who report on neglected tropical diseases

8/6/2019 WHO Report on Neglected Tropical Diseases

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Working to Overcome the Global Impact o Neglected Tropical Diseases Ann

First WHO report on neglected tropical diseases

Working to overcome

the global impact of

neglected tropical diseases



© World Health Organization 2010

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Design, layout and fgures: Denis Meissner, Claudia Corazzola, Christophe Grangier, WHO/GRA

Printed in FranceWHO/HTM/NTD/2010.1

WHO Library Cataloguing-in-Publication Data

First WHO report on neglected tropical diseases: working to overcome the global impact o neglected tropical diseases.

1 Tropical medicine - trends. 2 Endemic diseases. 3 Poverty areas. 4. Parasitic diseases. 5 Developing countries. 6. Annual reports.

I. World Health Organization

ISBN 978 92 4 1564090 (NLM Classifcation: WC 680)

Working to overcome the global impact of neglected tropical diseases was produced under the overall direction and supervision o

Dr Lorenzo Savioli (Director, WHO Department o Control o Neglected Tropical Diseases) and Dr Denis Daumerie (Programme Manager,

WHO Department o Control o Neglected Tropical Diseases), with contributions rom sta serving in the department.

Regional directors and members o their sta provided support and advice.

Valuable inputs in the orm o contributions, peer reviews and suggestions were received by members o the Strategic and Technical

Advisory Group or Neglected Tropical Diseases.

The report was edited by Proessor David W.T. Crompton, assisted by Mrs Patricia Peters.


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Contents

Foreword by the Director-General iii

Executive summary vii

PART 1

1. Neglected tropical diseases: a paradigm shif 1

1.1 Common eatures o neglected tropical diseases 2

1.2 New strategic approaches 2

1.3 Reocusing 3

1.4 Lessons learnt 4

2. Sixty years o growing concern 7

2.1 World Health Assembly resolutions 8

2.2 Landmarks in prevention and control 8

2.3 Strategic and echnical Advisory Group or Neglected ropical Diseases 10

3. Human and economic burden 13

3.1 Epidemiological burden 13

3.2 Economic burden 15

3.2.1 Economic impact 15

3.2.2 Costs o interventions 17

4. Ways orward 21

4.1 Approaches to overcoming neglected tropical diseases 21

4.1.1 Preventive chemotherapy 22

4.1.2 Intensifed case-management 25

4.1.3 Vector control 26

4.1.4 Sae water, sanitation and hygiene 28

4.1.5 Veterinary public health: 28

zoonotic aspects o neglected tropical diseases

4.2 Current policies and strategies 29

4.2.1 Te Global plan to combat neglected tropical diseases 2008–2015 31

4.2.2 Neglected tropical diseases and the Millennium Development Goals 32

4.2.3 Neglected tropical diseases and health-system strengthening 34


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PART 2

5. Neglected tropical diseases in the world today 39

5.1 Dengue 41

5.2 Rabies 47

5.3 rachoma 555.4 Buruli ulcer Mycobacterium ulcerans inection) 59

5.5 Endemic treponematoses 64

5.6 Leprosy Hansen disease) 69

5.7 Chagas disease American trypanosomiasis) 75

5.8 Human Arican trypanosomiasis sleeping sickness) 82

5.9 Leishmaniasis 91

5.10 Cysticercosis 97

5.11 Dracunculiasis guinea-worm disease) 103

5.12 Echinococcosis 107

5.13 Foodborne trematode inections 113

5.14 Lymphatic flariasis 117

5.15 Onchocerciasis river blindness) 123

5.16 Schistosomiasis bilharziasis) 129

5.17 Soil-transmitted helminthiases 135

6. Global and regional plans or prevention and control 143

6.1 Health targets 143

6.2 Regional plans 146

7. Conclusions 147

Overcoming neglected tropical diseases: 7 gains, 7 challenges 149

Annexes 153

1. Resolutions o the World Health Assembly on neglected tropical diseases 155

2. Ocial list o indicators or monitoring progress on the Millennium 159

Development Goals

3. Summary o metadata 163

4. Methods used to prepare maps and charts 169

Available in electronic ormat

WHO’s global and regional plans or prevention and control

Arican Region

Region o the Americas

Eastern Mediterranean Region

South-East Asia Region

Western Pacifc Region


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Foreword

hough medically diverse, neglected tropical diseases orm a group becauseall are strongly associated with poverty, all ourish in impoverished

environments and all thrive best in tropical areas, where they tend to co-exist. Most are ancient diseases that have plagued humanity or centuries.

Once widely prevalent, many o these diseases gradually disappeared romlarge parts o the world as societies developed and living conditions and hygieneimproved. oday, though neglected tropical diseases impair the lives o anestimated 1 billion people, they are largely hidden, concentrated in remote ruralareas or urban slums and shantytowns. Tey are also largely silent, as the peopleaected or at risk have little political voice.

Neglected tropical diseases have traditionally ranked low on national andinternational health agendas. Tey cause massive but hidden and silent suering,and requently kill, but not in numbers comparable to the deaths caused by HIV/AIDS, tuberculosis or malaria. ied as they are to impoverished tropical

Tackling neglected

tropical diseases:

a pro-poor

strategy on a

grand scale

by the Director-General o the World Health Organization


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settings, they do not spread to distant countries and only rarely aect travellersas, or example, during outbreaks o dengue. Because they are a threat only inimpoverished settings they have low visibility in the rest o the world. Toughgreatly eared in aected populations, they are little known and poorly understoodelsewhere. While the scale o the need or prevention and treatment is huge, the

poverty o those aected limits their access to interventions and the services neededto deliver them. Diseases linked to poverty likewise oer little incentive to industry to invest in developing new or better products or a market that cannot pay.

oday, neglected tropical diseases have their breeding grounds in the places leurthest behind by socioeconomic progress, where substandard housing, lack o access to sae water and sanitation, flthy environments, and abundant insects andother vectors contribute to ecient transmission o inection. Close companionso poverty, these diseases also anchor large populations in poverty. Onchocerciasisand trachoma cause blindness. Leprosy and lymphatic flariasis deorm in waysthat hinder economic productivity and cancel out chances or a normal social lie.

Buruli ulcer maims, especially when limbs have to be amputated to save a lie.Human Arican trypanosomiasis (sleeping sickness) severely debilitates beore itkills, and mortality approaches 100% in untreated cases. Without post-exposureprophylaxis, rabies causes acute encephalitis and is always atal. Leishmaniasis, inits various orms, leaves deep and permanent scars or entirely destroys the mucousmembranes o the nose, mouth and throat. In its most severe orm, it attacks theinternal organs and is rapidly atal i untreated. Chagas disease can cause youngadults to develop heart conditions, so that they fll hospital beds instead o thelabour orce. Severe schistosomiasis disrupts school attendance, contributes tomalnutrition and impairs the cognitive development o children. Guinea-wormdisease causes excruciating, debilitating pain, sometimes or extended periods

and oen coinciding with the peak agricultural season. Dengue has emerged as arapidly spreading vector-borne disease aecting mostly poor, urban populations;it is also the leading cause o hospital admissions in several countries.

Te consequences are costly or societies and or health care. Such costs includeintensive care or dengue haemorrhagic ever and clinical rabies, surgery andprolonged hospital stays or Chagas disease and Buruli ulcer, and rehabilitation orleprosy and lymphatic flariasis. For some diseases, such as sleeping sickness andleishmaniasis, treatments are old, cumbersome to administer and toxic. For others,especially the diseases that cause blindness, the damage is permanent. Clinicaldevelopment o rabies can be prevented through timely immunization aerexposure, but access to lie-saving biologicals is expensive and is not aordable inmany Asian and Arican countries. For most o these diseases, stigma and socialexclusion compound the misery, especially or women.

Fortunately, these problems are now much better documented and much morewidely recognized. Tey are also being addressed. Recent developments on severalronts have radically changed the prospects or controlling these diseases, andnew initiatives are enabling the people le behind by socioeconomic progress tocatch up. Te ambitions or health development have broadened, creating space or


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neglected tropical diseases. Te Millennium Declaration and its Goals recognizethe contribution o health to the overarching objective o reducing poverty. Eortsto control neglected tropical diseases constitute a pro-poor strategy on a grandscale. Te logic has changed: instead o waiting or these diseases to gradually disappear as countries develop and living conditions improve, a deliberate eort

to make them disappear is now viewed as a route to poverty alleviation that canitsel spur socioeconomic development.

As this report shows, reaching such an objective is now entirely easible or themasses o people known to be aected or at risk. Good medicines are availableor many o these diseases, and research continues to document their saety and ecacy when administered individually or in combination. Generous drugdonations by pharmaceutical companies have helped relieve some o the fnancialbarriers and allowed programmes to scale up coverage. A strategy o preventivechemotherapy, which mimics the advantages o childhood immunization, is beingused to protect entire at-risk populations and reduce the reservoir o inection. Teact that many o these diseases overlap geographically has practical advantages:preventive chemotherapy regimens are being integrated so that several diseases canbe tackled together, thus streamlining operational demands and cutting costs. Anintegrated approach to vector management likewise maximizes the use o resourcesand tools or controlling vector-borne diseases.

Governments and oundations have contributed substantial unds. Researchto develop new tools (such as medicines, diagnostics, vaccines and medicaldevices) and improve the delivery o existing ones has increased. Te momentumcontinues to grow. As the report shows, nearly 670 million people had been reachedwith preventive chemotherapy by the end o 2008. For some o these diseases,evidence indicates that, when a certain threshold o population coverage is

reached, transmission drops signifcantly; this raises the possibility that severalo these ancient diseases could be eliminated by 2020 i current eorts to scale upinterventions or preventive chemotherapy are increased.

While the report highlights a number o remaining challenges, the overallmessage is overwhelmingly positive. It is entirely possible to control neglectedtropical diseases. Aiming at their complete control and even elimination is ully

justifed, and this report sets out the solid evidence needed to achieve control.Above all, it makes the case or doing more, as an international community, torelieve hidden misery, on a grand scale, among people who would otherwise suerin silence.

Dr Margaret Chan

Director-General

World Health Organization


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Executive summary

Neglected tropical diseases (Ns) blight the lives of a billion people

worldwide and threaten the health of millions more. hese ancient

companions of poverty weaken impoverished populations, frustrate the

achievement of health in the Millennium evelopment oals and impede global

GHYHORSPHQWRXWFRPHV$PRUHUHOLDEOHHYDOXDWLRQRIWKHLUVLJQL¿FDQFHWRSXEOLFhealth and economies has convinced governments, donors, the pharmaceutical

industry and other agencies, including nongovernmental organizations (s), to

invest in preventing and controlling this diverse group of diseases. lobal efforts to

control “hidden” diseases, such as dracunculiasis (guinea-worm disease), leprosy,

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gains including the imminent eradication of dracunculiasis. ince 989 (when

most endemic countries began reporting monthly from each endemic village),

the number of new dracunculiasis cases has fallen from 89 055 in endemic

countries to 390 in 4 countries in 009, a decrease of more than 99%.

he orld ealth rganization () recommends five public-healthstrategies for the prevention and control of Ns: preventive chemotherapy;

intensified case-management; vector control; the provision of safe water,

sanitation and hygiene; and veterinary public health (that is, applying veterinary

sciences to ensure the health and well-being of humans). Although one approach

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and delivered locally.

Activities to prevent and control s are included in the policies and budgets

of many endemic countries. his has led to the development of interventions that

are appropriate to existing health systems, often with the support of implementing

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preventive chemotherapy during 008, although not all were given the full

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transmitted helminthiases and trachoma are being controlled mostly through this

approach. hese are a group of infections with a high disease burden for which

safe and simple treatments are available.


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Actions to address the suffering caused by Ns and assess how their impact

extends into sectors other than health will promote development by breaking the

cycle of poverty and disease; foster health security by reducing the vulnerability

of human and animal populations to infection; and strengthen health systems by

embedding strategic approaches and locally appropriate interventions into national

health programmes. he development of regional plans in response to the Global plan to combat neglected tropical diseases 2008–2015 has also led to growing

awareness of Ns and the suffering they cause.

he involvement of the pharmaceutical industry in Ns, and subsequent

donations made to support their control, have increased access to high-quality

medicines free of charge for hundreds of millions of poor people. he increasing

willingness and commitment of local and global communities of partners to

work with endemic countries have brought resources, innovation, expertise and

advocacy to efforts to overcome Ns. ntersectoral collaboration, involving

education, nutrition and agriculture, has reinforced N control.

$FKLHYLQJDQGVXVWDLQLQJLQWHQVL¿HGFRQWURORI17'VZLOOEHDFULWLFDOPLOHVWRQHfor in realizing its objective that all people attain the highest possible level

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of human African trypanosomiasis (T. b. gambiense) has fallen by 6%, from

86 in 999 to 0 3 in 008, and the number of newly reported cases of the

acute form (T. b. rhodesiense) has fallen by 58%, from 69 to 59, due largely to

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achievements in N prevention and control are to be sustained and extended.

espite global economic constraints, support from pain, the nited ingdom, the

nited tates, other countries, agencies and s will need to be sustained. hesecommitments should encourage others to expand their support for developing the

services needed to overcome Ns.

lanning for the development and control of Ns should take into account

the effects of porous borders, population growth and migration, urbanization, the

movement of livestock and vectors, and the political and geographical consequences

of climate change. everal of these factors help to explain the rapidly increasing

global spread of dengue. rom 00 to 009, a total of 6 66 950 cases were

reported to from more than 30 countries in ’s egion of the Americas,

where all four serotypes of the virus circulate. uring the same period, there were

80 6 cases of dengue haemorrhagic fever and 498 deaths reported to .engue has resurged in the region because successful vector surveillance and

control measures were not sustained after the campaign to eradicate Aedes aegypti,

the principal vector, during the 960s and early 90s. xplosive outbreaks now

occur every 35 years. he outh-ast Asia egion accounts for most deaths, but

the decline in case-fatality rates since 00 has been attributed mainly to effective

training in standardized case-management, based on a network of expertise, and

training materials developed by Member countries in the region.


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As control interventions reach more people and new technology is embraced,

quicker responses will need to be made to information about the epidemiology,

transmission and burden of Ns. imilarly, programme managers will need

to react quickly to information about the coverage, compliance, acceptance and

impact of interventions.

xpertise in individual Ns is lacking in some countries and continues to

decline in others. he decline in expertise is severe in the areas of vector control,

case-management, pesticide management and veterinary aspects of public health.

he ways to prevent and control rabies – a zoonotic disease that kills tens of

thousands of people annually in Africa and Asia and necessitates post-exposure

prophylaxis of more than 4 million patients worldwide following contact with

suspect rabid animals – are not known or well understood in many countries where

the disease exists.

As expansion of prevention and control activities increases, the need to

strengthen health systems, and to train and support staff in technical and

management expertise, will become more urgent.

argets for coverage set by the orld ealth Assembly for control of lymphatic

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not be met, especially in ’s African and outh-ast Asia regions, unless

interventions with preventive chemotherapy increase. n 008, only 8% of

people with schistosomiasis had access to high-quality medicines. onations of

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provide the quantities of this essential medicine needed to control schistosomiasis.

he provision of medicines to treat soil-transmitted helminthiases also must be

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more attractive to companies that manufacture generic pharmaceuticals.

A research strategy is required to develop and implement new medicines,

notably for leishmaniasis and trypanosomiasis; new methods for vector control;

vaccines for dengue; and new diagnostics that will be accessible to all who need

them.

he trategic echnical and Advisory roup for s, at its meeting in eneva

in late une 00, reviewed this report and commended it to the community

dedicated to the global prevention and control of these diseases of poverty.

he theme at the global partners’ meeting in eneva in April 00 was that

a turning point had been reached in the efforts to overcome Ns. he content

of this report demonstrates that there can be no turning back: the concept of

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Pa

1 Neglected tropical

diseases:

a paradigm shit

I

n 2003, the World Health Organization WHO) initiated a paradigm shi inthe control and elimination o a group o neglected tropical diseases NDs).Te process – led by the ormer Director-General, the late Dr JW Lee –

involved an important strategic change, rom a traditional approach centred ondiseases to one responding to the health needs o marginalized communities.

Te new approach uses integrated interventions based on tools or controllingNDs. From a public-health perspective, this change translated into the provisiono care and the delivery o treatment to underserved populations. Te shi

ensures a more ecient use o limited resources and the alleviation o poverty

and accompanying illness or millions o people living in rural and urban areas.

Tis emerging vision was sharpened at a meeting held in Berlin, Germany,

in December 2003 that convened experts rom diverse sectors, including public

health, economics, human rights, research, nongovernmental organizations

NGOs) and the pharmaceutical industry. Te meeting set the scene or WHO totranslate the new approach into a strategic policy and ormulate ways o providingpoor populations with an eective and comprehensive solution to some o their

health problems. From 2003 to 2007, bold steps were taken to develop a ramework or tackling NDs in a coordinated and integrated way. Details o the ramework are set out in section 4 o this report and in WHO’s Global plan to combat neglected

tropical diseases 2008–2015.

© E

r i c L a f f o r g u e




1.1 Common eatures o neglected tropical diseasesTe 17 neglected tropical diseases profled in this report share several common

eatures, which are summarized in Box 1.4.1. Te most proound commonality

is their stranglehold on populations whose lives are ravaged by poverty. During

the past decade, the international community’s recognition o this unacceptablesituation has stimulated the growth o a community o partners committed to

resolving this double bind o disease and poverty. Working to overcome the

impact o NDs represents a largely untapped development opportunity to

alleviate the poverty o many populations and thereby make a direct impact

on the achievement o the Millennium Development Goals (MDGs) as well as

ulflling WHO’s mission: ensuring attainment o the highest standard o healthas a undamental human right o all peoples.

1.2 New strategic approachesPreventive chemotherapy – a strategy frst used or delivering anthelminthic

medicines by means o a population-based approach – ocuses on optimizing

the use o single-administration medicines targeted simultaneously at more thanone orm o helminthiasis. Eorts to tackle helminth inections in a coordinatedashion can be traced back to the 2001 World Health Assembly resolution

WHA54.19 on schistosomiasis and soil-transmitted helminth inections, which

set common objectives and goals or their prevention and control.

Five years later in 2006, this concept was urther developed when WHO

published a manual on preventive chemotherapy in human helminthiases

recommending the integrated implementation o disease interventions againstthe our main helminth inections (lymphatic ilariasis, onchocerciasis,

schistosomiasis and soil-transmitted helminthiases) based on the coordinated useo a set o powerul anthelminthic medicines with an impressive saety record.

Preventive chemotherapy is now implemented worldwide and is used to treat

more than hal a billion people every year.

Te success o preventive chemotherapy is attributable to a number o actors

including:

the impact o preventive chemotherapy in reducing morbidity and

sustaining decreases in transmission; demonstration o the association o helminth inections with poverty and

disadvantage, and o the geographical overlap o the our main helminth

inections targeted;

the added beneft o controlling a number o inections and inestations

not specifcally targeted by the intervention (such as strongyloidiasis,

scabies and lice);



Neglected tropical diseases: a paradigm shit Pa

exibility o treatment that allows the expansion o its target to other

helminth inections (such as ascioliasis and other oodborne trematode

inections).

Te use o existing mechanisms to deliver anthelminthic medicines provides

a platorm to target other communicable diseases (such as trachoma) and pavesthe way or expansion o a public-health approach that shares common eatures

with immunization.

For protozoan and bacterial diseases, such as human Arican trypanosomiasis

(sleeping sickness), leishmaniasis, Chagas disease and Buruli ulcer ( Mycobacterium

ulcerans inection), the new ocus on improved and timely access to specialized

care through improved case detection and decentralized clinical management is

intended to prevent mortality, reduce morbidity and interrupt transmission.

ackling these diseases eectively requires specifc and proound expertise. In

the long term, WHO must ensure that sustainable steps are being taken to preventthese diseases and to promote the development o better, saer, more aordable

and simpler-to-use diagnostic methods and medicines.

Until such methods become available, the ocus remains on optimizing the useo existing treatments and expanding their access to a greater number o people,

who may immediately beneft rom a more coordinated strategic approach,

through innovative and intensifed case-management.

Te approach to vector control has also been revisited in light o the new,

integrated strategic ramework. Vector control now serves as an important cross-cutting activity aimed at enhancing the impact and the perormance o both

preventive chemotherapy and case-management. Integrated vector management

is an eective combination o dierent interventions and orms part o an

intersectoral and interprogrammatic collaboration within the health sector and

with other sectors, including agriculture and the environment. Its aim is to

improve the ecacy, cost-eectiveness, ecological soundness and sustainability

o disease control implemented against vector-borne NDs.

1.3 ReocusingFollowing its second meeting in Berlin in 2005, WHO proposed that the

vaguely defned term “other communicable diseases” be changed to the more

sharply ocused “neglected tropical diseases”. Tis change neatly encapsulated

the paradigm shi responsible or the new approach to dealing with NDs. Te

change recognizes that ND control can be achieved i three requirements are

met: (i) attention and action are given to the needs o populations aected by




© Sarah Cleaveland

NDs rather than to their diseases; (ii) interventions to deliver treatments are

integrated with control measures; and (iii) evidence-based advocacy is deployed

to generate resources or control rom the international community.

In April 2007, WHO convened its frst meeting o Global Partners on NDs,

which was attended by more than 200 participants, including representatives romWHO’s Member States, United Nations agencies, the World Bank, philanthropicoundations, universities, pharmaceutical companies, international NGOs and

other institutions dedicated to contributing their time, eorts and resources to

tackling these diseases.

1.4 Lessons learnt Te paradigm shi has enabled Member States and partners to fnd innovative

solutions to enable weak health systems to target the people most in need: the

poorest sectors o the population with limited or non-existent fnancial means.Grouping several diseases together under a new conceptual ramework

presents an opportunity to recalculate the collective burden associated with this

set o diverse aictions as well as their cumulative public-health relevance. Te

ramework has also enabled WHO to raise the profle o NDs and to mobilize

resources or scaling up implementation o activities or their global control and

elimination.

Tis report is confned to 17 NDs, although some comprise separate inectionsand thus separate diseases: or example, soil-transmitted helminthiases comprisethree separate inections and thereore three separate diseases. Tere are 149

countries and territories where NDs are endemic, at least 100 o which are

endemic or 2 or more diseases, and 30 countries that are endemic or 6 or more.



Neglected tropical diseases: a paradigm shit Pa

Box 1.4.1 Common eatures o neglected tropical diseases

A proxy or poverty and disadvantage

Neglected tropical diseases have an enormous impact on individuals, amilies and communities

in developing countries in terms o disease burden, quality o lie, loss o productivity and the

aggravation o poverty as well as the high cost o long-term care. They constitute a serious obstacle

to socioeconomic development and quality o lie at all levels.

Aect populations with low visibility and little political voice

This group o diseases largely aects low-income and politically marginalized people living in rural

and urban areas. Such people cannot readily inuence administrative and governmental decisions

that aect their health, and oten seem to have no constituency that speaks on their behal. Diseases

associated with rural poverty may have little impact on decision-makers in capital cities and their

expanding populations.

Do not travel widely

Unlike inuenza, HIV/AIDS and malaria and, to a lesser extent, tuberculosis, most NTDs generally do

not spread widely, and so present little threat to the inhabitants o high-income countries. Rather,

their distribution is restricted by climate and its eect on the distribution o vectors and reservoir

hosts; in most cases, there appears to be a low risk o transmission beyond the tropics.

Cause stigma and discrimination, especially o girls and women

Many NTDs cause disfgurement and disability, leading to stigma and social discrimination. In

some cases, their impact disproportionately aects girls and women, whose marriage prospects

may diminish or who may be let vulnerable to abuse and abandonment. Some NTDs contribute to

adverse pregnancy outcomes.Have an important impact on morbidity and mortality

The once-widespread assumptions held by the international community that people at risk o NTDs

experience relatively little morbidity, and that these diseases have low rates o mortality, have

been comprehensively reuted. A large body o evidence, published in peer-reviewed medical and

scientifc journals, has demonstrated the nature and extent o the adverse eects o NTDs.

Are relatively neglected by research

Research is needed to develop new diagnostics and medicines, and to make accessible interventions

to prevent, cure and manage the complications o all NTDs.

Can be controlled, prevented and possibly eliminated using effective and feasible

solutions

The fve strategic interventions recommended by WHO (preventive chemotherapy; intensifed case-

management; vector control; the provision o sae water, sanitation and hygiene; and veterinary

public health) make easible control, prevention and even elimination o several NTDs. Costs are

relatively low.



Sixty years o growing concern Pa

2 Sixty years o

growing concern

© W

H O

Since its ounding in 1948, WHO has led the common endeavour o protectingpeople rom inectious diseases, recognizing that the interests o its MemberStates are best served i the peoples o other countries are also helped to live

in healthy conditions 1).Tis report is the frst o its kind to review WHO’s work to prevent, control,

eliminate and eradicate 17 NDs. Section 5 provides a detailed account o these

diseases. History shows that NDs have not been overlooked or neglected by

WHO (2). Te Fih World Health Assembly, held in Geneva, Switzerland, in

May 1952, addressed the technical assistance needed by countries to deal with

treponematoses, rabies, leprosy, trachoma, hookworm, schistosomiasis and bothorms o flariasis 3). Tese diseases are included in WHO’s mandate today 4, 5),and it remains committed and available to attend to requests or prevention and

control rom countries where NDs are endemic.

In some ways, application o the term “neglected” to the communicable diseasesdiscussed in this report may appear inappropriate, since it is clear that WHO hasnever neglected them. Rather, WHO has consistently highlighted the impact thatthese diseases impose on its Member States. Te overt consequences o inectionwith the causative agents o NDs include skin ulcers, blindness, limb deormitiesand chronic pain. Less evident, but no less debilitating, are lesions to internal

organs, anaemia, growth retardation, impairment o cognitive development,




exercise intolerance and atigue, and the impairment o mental unctions

through neurological sequelae. Tese conditions blight the social, educational

and proessional lives o populations aected by NDS, most o whom are poor

people. Le untreated, diseases such as dengue haemorrhagic ever, human

Arican trypanosomiasis, visceral leishmaniasis and rabies are commonly atal.

Te heavy burden imposed by NDs on poor people has been gaining wider

recognition and prominence in countries and by institutions with the capacity to

release resources or prevention and control. Eective advocacy has successully

exploited the notion o “neglected” and stimulated health policy-makers to work

to overcome NDs in harmony with the ideals and aims o the MDGs. ools or

treatment interventions in communities can now reach the millions in need.

Resources are needed to support the research required to develop new medicinesand diagnostics, to produce and test tools or interventions, and to acilitate the

clinical management o several NDs.

Advocacy to support activities to overcome NDs must continue i resources

or extending sustainable relie are to be orthcoming. A record o the scale o

the most encouraging global response has been published in the Report o the

global partners’ meeting on neglected tropical diseases (6 ). In eect, partners at thatmeeting demonstrated their response to “the Golden Rule”, displayed as a mosaicby the 20th-century American painter and illustrator Norman Rockwell on a wallin the headquarters o the United Nations in New York: “Do unto others as you

would have them do unto you”.

2.1 World Health Assembly resolutions

Every year, the World Health Assembly – the supreme decision-making body

o WHO – evaluates the status o dierent health problems and decides whether

the adoption o a specifc resolution will add impetus to the eort designed to

bring relie, and so improve the quality o lie o populations at risk. Te frst

resolution on what are now termed NDs was adopted by the Second World

Health Assembly in 1949 Annex 1).

2.2 Landmarks in prevention and control

In addition to the work underpinning and justiying the resolutions o the WorldHealth Assembly, a series o initiatives has been proposed to orm partnerships,

strengthen measures and raise fnancial and other support to prevent and controlNDs Table 2.2.1).




Table 2.2.1 Summary o landmarks in overcoming neglected tropical diseases

1948 World Health Organization (WHO) begins work

WHO establishes Veterinary Public Health Programme

1952 UNICEF and WHO launch Global Yaws Programme

1960 WHO launches Programme or the Evaluation and Testing o New Insecticides

1974 Onchocerciasis Control Programme or West Arica begins

1976 Special Programme or Research and Training in Tropical Diseases established

1982 The Carter Center is inaugurated and begins work

1987 Mectizan® Donation Program created

1995 International Commission or the Certifcation o Dracunculiasis Eradication established

Arican Programme or Onchocerciasis Control set up

1997 Programme Against Arican Trypanosomiasis established

WHO-GET 2020 Alliance (Global Elimination o Trachoma by the year 2020) created

1998 Prime Minister Hashimoto o Japan presents his parasite-control initiative to the G8 Meeting

Global Buruli Ulcer Initiative established

Médecins Sans Frontières initiates a und to fght neglected tropical diseases rom the proceeds o itsNobel Peace Prize

1999 WHO Study Group on Future Trends in Veterinary Public Health established

2000 WHO Global Programme to Eliminate Lymphatic Filariasis launched

Bill & Melinda Gates Foundation created

Pan Arican Tsetse and Trypanosomiasis Eradication Campaign created

2002 WHO publishes Global defence against the infectious disease threat

Publication o the frst version o the WHO model formulary

2003 First issue o WHO’s newsletter Action Against Worms

Drugs or Neglected Diseases Initiative established

Berlin, Germany, hosts workshop on intensifed control o neglected diseases

2004 Third global meeting o the Partners or Parasite Control, leading to publication o Deworming for health and development

2005 Strategic and technical meeting on intensifed control o neglected tropical diseases held in Berlin, Germany

First International Conerence on the Control o Neglected Zoonotic Diseases: a route to poverty alleviation held at WHOheadquarters in Geneva, Switzerland

WHO Department o Control o Neglected Tropical Diseases established

Bangladesh, India and Nepal sign an agreement to eliminate visceral leishmaniasis by 2015

2006 Collaboration begins between WHO and the Foundation or Innovative New Diagnostics to develop and evaluate newdiagnostic tests or human Arican trypanosomiasis

Preventive chemotherapy in human helminthiasis: coordinated use of anthelminthic drugs in control interventions. A manual for health professionals and programme managers published by WHO

2007 Global partners’ meeting on neglected tropical diseases held at WHO headquarters in Geneva, Switzerland

Joint meeting on Integrated Control o Neglected Zoonotic Diseases in Arica, held in Nairobi, Kenya

2008 Launch o the Neglected Tropical Disease Initiative by the Government o the United States

Announcement that neglected tropical diseases are to be targeted ollowing a new £50 million commitment rom theDepartment or International Development o the Government o the United Kingdom




Most important has been the development by WHO o a ramework or actionthat gives equal attention to neglected communities and their health problems.

Te communities where NDs are entrenched have limited fnancial resources, ashortage o trained health workers and an urgent need or a stronger inrastructureto acilitate the delivery o health services 7 ). Implementation o this ramework still depends heavily on input rom countries where NDs are not endemic. Te

response has been signifcant, thanks to bilateral donations, the generosity o

the pharmaceutical industry, and the work o NGOs, implementing agencies,

universities and philanthropic institutions.

here is, however, growing recognition that successul and sustainable

control depend on the political commitment and ownership o interventions by

governments o countries where the diseases are endemic. In his Annual Report o 1951 8), Dr Brock Chisholm – the frst Director-General o WHO – was aware o this essential aspect o ND control. He declared, “oo oen countries requesting

assistance have been the object o well-meaning but disastrous attempts tosuperimpose on the local culture oreign patterns which, lacking the necessary

oundations, are bound to result in riction, misunderstanding and ultimate

ailure. In health work, as in all other felds o technical assistance, there can be

no question o simply transplanting techniques rom one place to another”.

2.3 Strategic and Technical Advisory Group or

Neglected Tropical Diseases

In 2007, WHO established a Strategic and echnical Advisory Group orneglected tropical diseases to support actions taken to overcome these diseases.

Te group serves as the principal advisory group to WHO and the Director-

General on matters relating to the prevention and control o NDs worldwide. Itsmain objective is to support the achievement o the goals contained in the Global

plan to combat neglected tropical diseases 2008–2015 5). Members have expertisein the range o NDs and represent disease-endemic countries, academia, donorsand agencies; the group is supported by WHO’s regional sta and secretariat.

In response to advice rom the Strategic and echnical Advisory Group, and

aer consultation with the global ND community, WHO established three

working groups, each with a remit to cover key aspects o managing the control

o NDs:

Working Group on access to quality-assured, essential medicines or

ND control, concerned with improving implementation, increasing

eectiveness, using economies o scale and developing aster sel-relianceby health authorities in endemic countries.




© Sarah Cleaveland

Working Group on monitoring and evaluation, concerned with the needso national programmes, monitoring disease-specifc indicators, and

monitoring coverage o interventions and their impact.

Working Group on anthelminthic drug ecacy, concerned with the

possible emergence o drug resistance, which could accelerate as access topreventive chemotherapy expands.

REFERENCES

1. Brockington F. World health. Harmondsworth, Penguin Books Ltd., 1958.

2. Account o the First World Health Assembly. Chronicle o the World Health Organization,

1948, 177(2):180–182.

3. Account o the Fih World Health Assembly. Chronicle o the World Health Organization ,

1952, 6:161–250.

4. Global deence against the inectious disease threat . Geneva, World Health Organization,

2003 (WHO/CDS/2003.15).

5. Global plan to combat neglected tropical diseases 2008–2015. Geneva, World Health

Organization, 2007 (WHO/CDS/ND/2007.3).

6. Report o the global partners’ meeting on neglected tropical diseases: a turning point .

Geneva, World Health Organization, 2007 (WHO/CDS/ND/2007.4).

7. Intensifed control o neglected diseases: report o an international workshop, Berlin,

10–12 December 2003. Geneva, World Health Organization, 2004 (WHO/CDS/CPE/

CEE/2004.45).

8. Te work WHO: 1951. Annual report o the Director-General to the World Health

Assembly and to the United Nations. Chronicle o the World Health Organization, 1952,

6(7-8):170.



Human and economic burden Pa

3 Human and

economic burden

© U

N

3.1 Epidemiological burden

Te concept o DALYs (disability-adjusted lie years) was developed to enable

the burden o individual diseases to be assessed quantitatively and comparatively.Te number o DALYs assigned to a specifc disease at a particular time gives

an estimate o the sum o years o potential lie lost due to premature mortality

and the years o productive lie lost. WHO’s Department o Health Statistics andInormatics has compiled and published estimates o DALYs or 2004 (1). Te

DALYs or a selection o NDs discussed in this report are set out in Table 3.1.1.

Public-health planners ace the problem o setting priorities or attention – anecessary task since competition or the most eective use o resources is

inevitable.




Table 3.1.1 Estimated number o disability-adjusted lie years (DALYs) (in thousands) by cause (neglected

tropical disease), and by WHO region (excluding the European Region)a, 2004

Neglected tropical disease Worldb

WHO region

Arican AmericasEastern

Mediterranean

South-East

Asia

Western

PacifcHuman Arican

trypanosomiasis1 673 1 609 0 62 0 0

Chagas disease 430 0 426 0 0 0

Schistosomiasis 1 707 1 502 46 145 0 13

Leishmaniasis 1 974 328 45 281 1 264 51

Lymphatic flariasis 5 941 2 263 10 75 3 525 65

Onchocerciasis 389 375 1 11 0 0

Leprosy 194 25 16 22 118 13

Dengue 670 9 73 28 391 169

Trachoma 1 334 601 15 208 88 419

Ascariasisc 1 851 915 60 162 404 308

Trichuriasisc 1 012 236 73 61 372 269

Hookworm diseasec 1 092 377 20 43 286 364

a ource: The global burden of disease: 2004 update (1). b Because estimates from the uropean egion were omitted from the table, numbers for the regions may not always add up to the world’s total.c oil-transmitted helminthiases.

Te published sources rom which these tables are based should be consulted or details o the costs involved.

Tere is consensus about the need or DALYs or an objective measure o the

burden o disease. However, there is some criticism o the procedures used to makethe estimates, and considerable concern about the quality and reliability o the rawdata available or generating the estimates. Four reasons may be oered to supportthis cause or concern. Firstly, or any disease there may be little inormation on

numbers o cases and deaths because surveillance systems and platorms or mostNDs and inections in animal reservoirs are weak or non-existent. Secondly,

national and regional estimates or some diseases are oen derived rom a ew

studies carried out in high-risk populations. Tirdly, or some conditions, such asschistosomiasis, there is uncertainty about the accuracy o the disability weightsthat should be attached to small or moderate reductions in physical unction, to




pain and to other orms o impairment. Small dierences in disability weights,

when multiplied by large numbers o aected people, yield highly variable

estimates o DALYs lost. Fourthly, the less overt or subtle morbidity o the highly prevalent NDs aects the severity o concurrent inection and disease. DALY

estimates still have to take account o this complication.

Estimates o DALYs or Buruli ulcer, cysticercosis, dracunculiasis,

echinococcosis, endemic syphilis, oodborne trematode inections (clonorchiasis,ascioliasis, opisthorchiasis) and rabies are not explicitly stated. However, they

contribute to the burden o disease caused by NDs, and some have exceedingly high mortality i le undiagnosed and untreated.

3.2 Economic burden

'DWDDERXWWKHHFRQRPLFEXUGHQRI17'VDUHFRQ¿QHGWRVPDOOVWXGLHVLQlimited geographical areas. More work is needed to quantify the impact of

Ns on the productivity of women. here data exist, the economic impact is

VLJQL¿FDQWRUH[DPSOHO\PSKDWLF¿ODULDVLVFDXVHVDOPRVWELOOLRQD\HDULQ

lost productivity (2) and the annual global expenditure for rabies prevention and

FRQWUROH[FHHGVELOOLRQE\:+2¶VFRQVHUYDWLYHDVVHVVPHQW

3.2.1 Economic impact

7KHUHLVDQXQTXDQWL¿DEOHGLPHQVLRQWRWKHEXUGHQRI17'VWKDWVDSVWKHunpaid work and productivity of millions of women. n countries where Ns

are endemic, women are the caregivers when children and family members are

healthy and when they are sick; they collect water and fuel, grow vegetables and

tend crops, provide meals and maintain the household (3). his vital work is

unpaid and would be easier if women were relieved from the burden of Ns. n

low-income countries, children are an economic resource, and improving their

health will help them better perform their daily tasks.

$TXDQWL¿DEOHGLPHQVLRQWRWKHEXUGHQRIGLVHDVHFDXVHGE\17'VLVWKHORVV

of productivity and its impact on the productivity of individuals, households,

communities and nations. hat people with poor health and crippling disabilities

are less productive than their healthy counterparts cannot be challenged,

EXWFDUHIXOO\VWUDWL¿HGDQDO\VHVRIWKHUHVXOWVRIZHOOGHVLJQHGODUJHVFDOH

LQYHVWLJDWLRQVDUHUDUHQGHUVWDQGLQJWKHHIIHFWRI17'VRQSURGXFWLYLW\ZLOO

help promote prevention and control activities, and assure governments and

donors that resources directed towards these endeavours are a good investment.

nformation about the impact of several Ns is shown in Table 3.2.1.1.




Table 3.2.1.1 Economic costs o selected neglected tropical diseasesa (data are the latest available)

Disease Setting Reported productivity lossb

Chagas disease Latin America

Estimated 752 000 working days/year lost due to premature deaths.

US$ 1.2 billion/year in lost productivity in 7 southernmost countries.Absenteeism o workers aected by Chagas disease in Brazil represented anestimated minimum loss o US$ 5.6 million/year.c

Cysticercosis

Eastern Capeprovince(South Arica),Honduras, India

The societal monetary cost o Taenia solium cysticercosis was estimated atUS$ 15.27 million (95% CI US$ 51.6–299 million) in India, US$ 28.3 million(US$ 7.1–42.9 million) in Honduras and US$ 16.6 million (US$ 8.3–22.8 million)in the Eastern Cape province (South Arica). The total annual costs associated withcysticercosis were estimated at US$ 13 million; the monetary burden per case ohuman cysticercosis amounted to US$ 252.

Dengue ever India

The average total economic burden was estimated at US$ 29.3 million(US$ 27.5–31.1 million).

Costs in the private health sector were estimated to be almost 4 times that o publicsector expenditures.

Echinococcosis GlobalThe fnancial burden o the disease in estimates o purchasing power parity is4.1 billion international dollars annually, o which 46% is due to human treatmentand morbidity and 54% is associated animal-health costs.

Lymphatic

flariasis

Various

countries

Annual economic burden o lymphatic flariasis measured in lost productivityreported in 1998 was about US$ 1.7 billion in 2008, taking into account ination incountries that are part o the Arican Programme or Onchocerciasis Control.

ERRs are 25% at the end o the investment period in 2019, and 28% over 30years. The programme breaks even in the tenth year.

Lymphatic flariasis causes almost US$ 1.3 billion/year in lost productivity.

Soil-transmitted

helminthiases Kenya

On the basis o the estimated rate o return to education in Kenya, deworming islikely to increase the net present value o wages by more than US$ 40 per treatedperson. Beneft-to-cost ratio = 100. Deworming may increase adult income by40%.

Schistosomiasis PhilippinesAter a series o computations, o which the disability rate was regarded as themost important, a total o 45.4 days o-work lost per inected person/year wasobtained.

Trachoma Variouscountries

The economic cost o t rachoma in terms o lost productivity is estimated atUS$ 2.9 billion annually.

CI = confdence interval; ERR = economic rate o return.a Source: Reproduced with permission rom Conteh L et al. (4).b All costs and losses are inated rom their original year o calculation and converted to their 2008 US$ equivalent with a constant dollar rate.c Te base year o costs is not given, so costs remain in original orm.





© Sarah Cleaveland

3.2.2 Costs o interventions

Assessing the burden o NDs in terms o DALYs is a powerul approach

that can be used to evaluate the gains made, and the costs o interventions ortheir prevention and control. Put simply, how many DALYs can be averted by

investing ully in a programme to control NDs including the costs o planning,

administration, stang, training, community relations, logistics, medicines,

procurement and reporting)? For example, the cost o treating a patient with

lymphatic flariasis using ivermectin and albendazole (donated by Merck & Co.,

Inc., and GlaxoSmithKline) ranges rom US$ 0.05 to US$ 0.10 per person treated,

while the cost o the DALYs averted is reckoned to be US$ 5.90. Results o this

sort are encouraging or ND control provided that the ull costs o intervention

have been identifed.

An economic analysis o deworming campaigns among school-aged children

conducted in seven countries (Cambodia, Egypt, Ghana, the Lao People’s

Democratic Republic, Myanmar, the United Republic o anzania and Viet Nam)calculated a cost o US$ 0.07 per each round o drug distribution or US$ 70 000

to cover 1 million school-aged children), with minimal variation among countries(5). Tis calculation includes the costs o training, health education, procurementand distribution o medicines, media campaigns, monitoring and supervision.

Economic evaluations o the Onchocerciasis Control Programme in west Aricashow a net present value equivalent discounted benefts minus discounted costs)

o US$ 919 million or the programme over 39 years, using a conservative 10%

rate to discount uture health and productivity gains. Te net present value or theArican Programme or Onchocerciasis Control is calculated at US$ 121 million

over 21 years, also using a 10% discount rate. However, the economic success

o ivermectin distribution is sensitive to the act that the drug itsel has been

donated. Te market value o donations made by Merck & Co. Inc., to the AricanProgramme or Onchocerciasis Control or just 1 year considerably outweighs

the benefts calculated or both the Onchocerciasis Control Programme and

the Arican Programme or Onchocerciasis Control over the duration o theseprojects.

Table 3.2.2.1VXPPDUL]HVWKH¿QGLQJVRIDQDWWHPSWWRFDOFXODWHWKH'$/<V

averted for several Ns in relation to the costs of their treatment and control.

he published sources from which this table is based should be consulted for

details of the costs involved.




Table 3.2.2.1 Cost-eectiveness o controlling neglected tropical diseasesa

Disease InterventionCost per DALYaverted (US$)

Chagas disease Vector control 317

Lymphatic flariasis

In implementation units (districts) where prevalence is greater than 1%, annualmass drug administration to treat the entire at-risk population or 5–7 years:ivermectin and albendazole in Arica, and diethylcarbamazine and albendazole inonchocerciasis-ree countries:

x to interrupt transmission and achieve elimination o the public-healthproblem

x to initiate morbidity control, surgery and lymphoedema management

To provide salt ortifed with diethylcarbamazine (China)

Vector control

5–10

35

1–4

59–370

Schistosomiasis

Mass school-based treatment with praziquantel and albendazole combined with

schistosomiasis treatment

Mass school-based treatment with praziquantel alone

10–23

410–844

TrachomaTrachoma control based on SAFE strategy (Surgery, Antibiotic treatment, Facewashing and Environmental control)

5–100

Onchocerciasis Community-directed treatment programmes with ivermectin 9

Soil-transmittedhelminthiases(hookworm,roundworm, andwhipworm)

Mass school-based treatment with albendazole or mebendazole 2–11

LeprosyCase-detection and treatment with multidrug therapy using donated drugs

Prevention o disability

46

1–122

Dengue ever controlCase-management

Environmental control

716–1757

more than 2440

Leishmaniasis Case detection and treatment; vector control. 11–22

Human Arican

trypanosomiasis

Case-fnding and treatment:

Less than 12

Less than 24

a Source: Reproduced with permission rom Conteh L et al. (4).





REFERENCES

1. Te global burden o disease: 2004 update. Geneva, World Health Organization, 2008.

2. Ramaiah KD et al. Te economic burden o lymphatic flariasis in India. Parasitology

oday, 2000, 16:151-253.

3. Momson JH, Kinnard V, eds. Dierent places, dierent voices. London, Routledge, 1993.

4. Conteh L, Engels , Molyneux D. Socioeconomic aspects o neglected tropical diseases.

Lancet , 2010, 375:239–247.

5. Montresor A et al. Estimation o the cost o large-scale school deworming programmes

with benzimidazoles. ransactions o the Royal Society o ropical Medicine and Hygiene,

2010, 104:129–132.



Ways orward Pa

4 Ways orward

© W

H O

4.1 Approaches to overcoming neglected tropical

diseases

WHO recommends fve strategies or the prevention and control o NDs: (i)

preventive chemotherapy; (ii) intensifed case-management; (iii) vector control;

(iv) provision o sae water, sanitation and hygiene; and (v) veterinary public

health. Working to overcome individual NDs or a group o these diseases shouldrely on a combination o the fve strategic approaches. For example, in order to

control the morbidity caused by lymphatic flariasis, individuals will beneft

rom preventive chemotherapy; individuals with hydrocoele will require case-

management. Bringing the vectors o Wuchereria and Brugia under control will

require appropriate management o water resources. Te SAFE strategy Surgery,Antibiotic treatment, Facial cleanliness and Environmental improvement) used




to control trachoma combines the large-scale distribution o medicines with

individual case-management and environmental improvement. Surgery or

trichiasis prevents progression to blindness. Azithromycin or tetracycline eye

ointment oered to populations at risk cures the inection and reduces person-

to-person transmission.

WHO osters technical expertise in each strategy. Sustaining the health

benefts will require integration and implementation o the strategies within the

national health programmes o countries where NDs are endemic. Tis vision

is encapsulated in most i not all o the resolutions o the World Health Assembly pertaining to NDs ( Annex 1) irrespective o specifc, measurable public-health

targets.

4.1.1 Preventive chemotherapy

Developed by WHO to control morbidity in populations at risk o inection

or illness, preventive chemotherapy depends on the large-scale distribution o

high-quality, saety-tested medicines. Preventive chemotherapy is the main

intervention or controlling lymphatic flariasis, onchocerciasis, schistosomiasis

and soil-transmitted helminthiases. Tis intervention contributes to the control

o trachoma and, depending on the choice o medicine, relieves strongyloidiasis,scabies and lice.

he application o preventive chemotherapy as a public-health measure

to control helminthiasis depends on the mass distribution o seven broad-

spectrum anthelminthic medicines: albendazole, diethylcarbamazine,ivermectin, levamisole, mebendazole, praziquantel and pyrantel (Table 4.1.1.1).

WHO recommends these medicines be used not only because o their ease o

administration and ecacy but also because o their excellent saety profles

and minimal side-eects 1). Te saety record o these medicines when used orpreventive chemotherapy is such that individual diagnosis is not justifed in areaso high endemicity. Tese medicines are administered as a single, oral dose, eitheras a single-dose tablet (e.g. albendazole 500 mg or mebendazole 400 mg) or as a

dose calculated according to weight or height (dose poles are used to calculate

doses or ivermectin and praziquantel). As a result, non-medically trained people,including schoolteachers and community volunteers, can be recruited to deliver

these medicines to many people who are beyond the reach o the peripheral

health-care system (2). Te requency o administration ranges rom once to

twice yearly, according to the prevailing epidemiology o the targeted inections.Preventive chemotherapy using azithromycin to control morbidity in trachoma

orms an eective component o the SAFE strategy. Guidance on the optimum useo preventive chemotherapy under a range o conditions is explained in WHO’s

manual on preventive chemotherapy in human helminthiasis 3).



Ways orward Pa

Table 4.1.1.1 WHO-recommended anthelminthic medicines or use in preventive chemotherapya,b,c

Disease Albendazole MebendazoleDiethyl-

carbamazineIvermectin Praziquantel Levamisoled Pyranteld

T a r g e t d i s e a s e s o r w h i c h a w

e l l -

d e f n e d s t r a t e g y i s a v a i l a b l

e Ascariasis √ √ – (√) – √ √

Hookworm √ √ – – – √ √

Lymphatic

flariasis√ – √ √ – – –

Onchocerciasis – – – √ – – –

Schistosomiasis – √ – –

Trichuriasis √ √ – (√) – (√)e (√) e

T a r g e t d i s e a s e s o r w h i c h a

s t r a t e g y i s b e i n g d e v e l o p e d Clonorchiasis – – – – √ – –

Opisthorchiasis – – – – √ – –

Paragonimiasis – – – – √ – –

Strongyloidiasis √ (√) – √ – –

Taeniasis – – – –√

up to 10 mg/ kg

– –

A d d i t i o

n a l b e n e f t s

Cutaneous

larva migrants

(zoonotic

ancylostomiasis)

√ (√) – (√) – (√) (√)

Ectoparasitic

inections

(scabies and

lice)

– – – √ – – –

Enterobiasis √ √ – (√) – (√) √

Intestinal

trematodiases– – – – √ – –

Visceral larva

migrants

(toxocariasis)

– – √ (√) – – –

a Source: adapted rom Preventive chemotherapy in human helminthiasis (3).b Prescribing inormation and contraindications are given in the WHO model ormulary 2004.c In this table, √ indicates medicines recommended by WHO or treatment o the relevant disease, and (√) indicatesmedicines that are not recommended or treatment but that have a (suboptimal) eect against the disease.

d At present, levamisole and pyrantel do not have a prominent role in preventive chemotherapy as described inthis manual. However, they remain useul drugs or treating soil-transmitted helminthiases, and since – unlikealbendazole and mebendazole – they do not belong to the benzimidazole group, they are expected to contribute to themanagement o drug-resistant soil-transmitted helminthiases should that problem emerge.

e Levamisole and pyrantel have only a l imited eect on trichuriasis but, when used in combination with oxantel,pyrantel has an ecacy against trichuriasis comparable to that observed with mebendazole.




Progress towards including preventive chemotherapy in control programmes

has been made in some endemic countries, but a considerable scale up will

be needed i targets set in resolutions o the World Health Assembly are to be

met ( Annex 1). Global coverage o preventive chemotherapy or the specifc

orms o helminthiasis is shown in Figure 4.1.1.1. Te coverage rates are basedon inormation that is available rom WHO’s preventive chemotherapy and

transmission control databank (4). A clear dierence is noticeable between the

rates o coverage or onchocerciasis, lymphatic flariasis, schistosomiasis and soil-transmitted helminthiases. Te quality and completeness o data are better or

onchocerciasis and lymphatic flariasis, probably because the medicines used to

treat these diseases are available in sucient quantities as part o donations made

by the private sector. For reporting purposes, countries are required to submit

detailed progress reports beore the next year’s supply o donated drugs can be

granted.

For soil-transmitted helminthiases and schistosomiasis, the situation is

dierent. Even though a large proportion o the population aected by soil-

transmitted helminthiases receives albendazole through the Global Programme

to Eliminate Lymphatic Filariasis, there is a need to purchase large quantities o

generic medicines or reaching persons aected by this disease in areas where

lymphatic ilariasis is not endemic. Given the large quantities o medicine

needed to achieve the required coverage or schistosomiasis and soil-transmitted

helminthiases, and the strict timing required or the medicines to be available atthe country level, some orm o centralized drug supply mechanism should be

established, as it is or vaccines supplied or routine immunization.

In act, preventive chemotherapy or schistosomiasis and soil-transmitted

helminthiases may have higher coverage than that shown in Table 4.1.1.2.

he reported low coverage may be explained by diiculties encountered in

collecting and managing data. Since many community-based treatments or

schistosomiasis and soil-transmitted helminthiases are delivered by a diverse

range o organizations and nongovernmental development organizations, there isa need or greater coordination in reporting. Coverage data are not systematically reported to national authorities by all implementing agencies and are not routinely sent on to the regional and global level o WHO, leading to an underestimation

o the numerator. Te denominator in calculating coverage may not always be

reliable or soil-transmitted helminthiases and particularly or schistosomiasis,

which is a highly ocal disease.



Ways orward Pa

© Sarah Cleaveland

Fig. 4.1.1.1 Global coverage (%)a o preventive chemotherapyor schistosomiasis, soil-transmitted helminthiases,lymphatic flariasis and onchocerciasisb

0

70

2 0 0 5

Year

C o v e r a g e ( % )

60

50

40

30

20

10

2 0 0 6

2 0 0 7

2 0 0 8

2 0 0 5

2 0 0 6

2 0 0 7

2 0 0 8

Schistosomiasis Soi l-transmit tedhelminthiases

2 0 0 5

2 0 0 6

2 0 0 7

2 0 0 8

Lymphaticflariasis

2 0 0 5

2 0 0 6

2 0 0 7

2 0 0 8

Onchocerciasis

a Coverage shown is the proportion o the global population requiring preventive chemotherapy with the appropriatepackage o medicine or each helminthic inection that has been treated annually between 2005 and 2008. For soil-transmitted helminthiases, the target population is children aged 1–15 years.

b Source: WHO preventive chemotherapy and transmission control databank (available at: http://www.who.int/neglected_diseases/preventive_chemotherapy/databank/en/).

Table 4.1.1.2 Number o people reached by preventive chemotherapy or at least one

neglected tropical disease, 2008

WHO region Number o countriesreporting to WHO

Number o people reached by preventivechemotherapy or at least one disease

Arican 34 167 575 966

Americas 16 10 987 288

Eastern Mediterranean 7 14 986 795

European 1 37 319

South-East Asia 9 437 651 823

Western Pacifc 8 36 831 068

Global 75 668 070 259

4.1.2 Intensifed case-management Intensifed case-management involves caring or inected individuals and

those at risk o inection. Te key processes are (i) making the diagnosis as early

as possible, (ii) providing treatment to reduce inection and morbidity, and (iii)

managing complications. Tis intervention is justifed as a principal strategy or

controlling and preventing those NDs or which there are no medicines available




or preventive chemotherapy. Inection may be asymptomatic or long periods

and require confrmation o diagnosis because o the toxicity o medicines. WHOocuses on the prevention and control o Buruli ulcer, Chagas disease, human

Arican trypanosomiasis, leishmaniasis (in its cutaneous, mucocutaneous

and visceral orms), leprosy and yaws. For Chagas disease, human Arican

trypanosomiasis and visceral leishmaniasis, diagnosis needs to be simplifed and

made less invasive without losing sensitivity. For these six and other NDs, there

is an urgent need to shorten the length o time that occurs between suspecting

inection and making the diagnosis so that treatment can begin without delay.

Innovative work is required to improve diagnostic methods and provide saer

medicines or administration under shorter treatment regimens.

Te medicines or treatment o the six target diseases include niurtimox

and benznidazole or Chagas disease; pentamidine, suramin, melarsoprol,

eornithine and niurtimox or human Arican trypanosomiasis; pentavalent

antimonials sodium stibogluconate and meglumine antimoniate), amphotericinB, paromomycin and milteosine or visceral leishmaniasis; multidrug therapy

or leprosy using a combination o riampicin, cloazimine and dapsone or

multibacillary leprosy, and riampicin and dapsone or paucibacillary leprosy; a

combination o riampicin and streptomycin or amikacin or Buruli ulcer; and

benzathine penicillin or yaws. Most o these medicines are donated to WHO,

acilitating the delivery o high-quality treatment ree o charge to targeted

populations in endemic areas.

4.1.3 Vector control

Vector-borne diseases account or about 16% o the estimated global burden

o communicable diseases (5). Most NDs involve vector transmission: insects

transmit the inectious agents o dengue and other virus-induced diseases, Chagasdisease, human Arican trypanosomiasis, leishmaniasis, lymphatic flariasis

and onchocerciasis; snails are essential in transmitting the agents o oodborne

trematodiasis and schistosomiasis; crustaceans are essential or transmission o

the agents o dracunculiasis and oodborne paragonimiasis. Understanding vectorbiology is an essential component or explaining and predicting the epidemiology o vector-borne disease.

Te promotion o integrated vector management is a component o the Global

plan to combat neglected tropical diseases 2008–2015 6 ). Tis approach to vector

control requires a rational decision-making process to optimize the use o

resources. Eective integrated vector management will be strengthened through



Ways orward Pa

makes clear that much o the morbidity and mortality resulting rom NDs has amajor zoonotic component. Zoonotic diseases (zoonoses) are those diseases arisingrom inections transmitted between vertebrate animals and people. Te animalsmay be domesticated (livestock or companion) or wild. NDs with a zoonotic

component – including brucellosis cysticercosis, echinococcosis, oodborne

trematodiasis, human Arican trypanosomiasis, leishmaniasis and rabies as

priority negleted zoonoses – are associated with people living in close proximity to animals. Zoonotic diseases are also actors in the persistence o poverty in

places where income and productivity depend on animal health. Control o thesediseases in livestock requires interventions that do not threaten the economic

security o populations whose livelihoods are dependent on animals. Tere is a

crucial role or veterinarians in the public-health arena.

4.2 Current policies and strategiesExtracts o reports rom recent G8 summit meetings are shown in boxes 4.2.1,

4.2.2 and 4.2.3. Te G8 countries are committed to action to relieve the burden o suering rom NDs, thereby making a signifcant contribution to the attainmento the MDGs.

Box 4.2.1

34th G8 Summit – Toyako, Japan, July 2008

Report o the G8 Health Experts Group to the G8 leadersa

For the 2008 meeting o G8 leaders, the Japanese Presidency established the G8 Health Experts Group to review and

recommend methods to overcome the inectious diseases that continue to challenge and impair human health and

development. The Group’s report ocuses on how the commitment o the G8 to the improvement o health will make a

signifcant contribution to the attainment o the Millennium Development Goals.

Importantly, or the diverse community o agencies working with WHO to overcome NTDs, section 25 o the report

states:

“An estimated one billion people are aected by a range o neglected tropical diseases (NTD) which cause substantial

health, economic and social burdens in poor countries. Eorts to control or eliminate NTDs need to be invigorated. The

G8 will work to support the control or elimination o diseases listed by the WHO through such measures as research,

diagnostics and treatment, prevention, awareness-raising and enhancing access to sae water and sanitation. In this

regard, by expanding health system coverage, alleviating poverty and social exclusion as well as promoting adequateintegrated public health approaches, including through the mass administration o drugs, we will be able to reach at

least 75% o the people aected by certain major neglected tropical diseases in the most aected countries in Arica,

Asia and Latin America, bearing in mind the WHO Plan. With sustained action or 3–5 years, this would enable a very

signifcant reduction o the current burden with the elimination o some o these diseases.”

a Toyako Framework or Action on Global Health: report o the G8 Health Experts Group (available at http://www.moa.go.jp/policy/economy/ summit/2008/doc/pd/0708_09_en.pd).

ˉ

ˉ




Box 4.2.2

35th G8 Summit – L’Aquila, Italy, July 2009

G8 Leaders Declaration: Responsible leadership or a sustainable uturea

“We warmly support building a global consensus on maternal, newborn and child health as a way

to accelerate progress on the Millennium Development Goals or both maternal and child health,

through (i) political and community leadership and engagement; (ii) a quality package o evidence-

based interventions through eective health systems; (iii) the removal o barriers to access or all

women and children, ree at the point o use where countries chose to provide it; (iv) skilled health

workers; (v) accountability or results. We encourage the work o the WHO, WB, UNICEF and UNFPA

are doing to renew international eorts on maternal and child health. We will implement urther

eorts towards universal access to HIV/AIDS prevention, treatment, care and support by 2010,

with particular ocus on prevention and integration o services or HIV/TB. We will combine this

with actions to: combat TB and Malaria; address the spread o Neglected Tropical Diseases andwork towards completing the task o polio eradication; improve monitoring o emerging inectious

diseases. In this regard, we stress the importance o addressing gender inequality.”

a Responsible leadership or a sustainable uture (available at http://www.g8italia2009.it/static/G8_Allegato/ G8_Declaration_08_07_09_fnal,0.pd).

Box 4.2.3

36th G8 Summit – Muskoka, Canada, June 2010

G8 Muskoka Declaration: Recovery and new beginningsa

“We reafrm our commitment to come as close as possible to universal access to prevention,

treatment, care and support with respect to HIV/AIDS. We will support country-led eorts to achieve

this objective by making the third voluntary replenishment conerence o the Global Fund to Fight

AIDS, TB and Malaria in October 2010 a success. We encourage other national and private sector

donors to provide fnancial support or the Global Fund. We commit to promote integration o HIV

and sexual and reproductive health, rights and services within the broader context o strengthening

health systems. G8 donors also remain steadast in their support or polio eradication and remain

committed to a polio-ree world. We continue to support the control or elimination o high-burden

Neglected Tropical Diseases (NTDs).”

a G8 Muskoka Declaration: recovery and new beginnings (available at http://g8.gc.ca/wp-content/uploads/2010/07/ declaration_eng.pd).



Ways orward Pa

Table 4.2.2.1 The contribution o the control o neglected tropical diseases (NTDs) to attaining health in

the Millennium Development Goalsa (MDGs) – excerpts rom World Health Assembly (WHA)

resolutions and other relevant resolutions

Public healthproblem

Selected WHA

resolutionsb and otherrelevant resolutions

Title Year

MDG

associatedwith NTDs

1 Dracunculiasis WHA57.9 (RecallingWHA50.35, WHA44.5)

Eradication o dracunculiasis 2004 1, 6

WHA42.29 (RecallingWHA39.21)

Elimination o dracunculiasis 1989 1, 6

2 Lymphatic flariasis EM/RC47/R.11 Elimination o lymphatic flariasis in theEastern Mediterranean Region

2000 6, 8

WHA50.29 Elimination o lymphatic flariasis as a publichealth problem

1997 6

WHA43.18 Tropical disease research 1990 4, 6, 8

WHA42.31 Control o disease vectors and pests 19891, 7, 8

3 Onchocerciasis WHA47.32 Control o onchocerciasis through ivermectindistribution

1994 6

WHA42.31 Control o disease vectors and pests 1989 1,7

4 Schistosomiasis WHA54.19 Schistosomiasis and soil-transmittedhelminth inections

2001 3–8

5 Soil-transmit tedhelminthiases

WHA54.19 Schistosomiasis and soil-transmittedhelminth inections

2001 3–8

6 Taeniasis/ Cysticercosis

WHA31.48 Prevention and control o zoonoses andoodborne diseases due to animal products

1978 1, 6, 8

7 Humanechinococcosis


1978 1, 6, 8

8 Blinding trachoma WHA51.11 Global elimination o blinding trachoma 1998 1, 3–8

9 Fascioliasis WHA31.48 Prevention and control o zoonoses andoodborne diseases due to animal products

1978 1, 6, 8

10 Yaws WHA31.58 Control o endemic treponematoses 1978 1, 6

11 Dengue SEA/RC61/R5 Dengue prevention and control 2008 6, 8

WPR /RC59.R6 Dengue ever and dengue haemorrhagicever prevention and control

2008 6, 8

WHA55.17 Prevention and control o dengue ever and

dengue haemorrhagic ever

2002 6, 8

CD43.R4 Dengue and dengue haemorrhagic ever 2001 6, 8

12 Rabies CD48.R13 15th Inter-American Meeting at ministeriallevel on health and agriculture (RIMSA):“Agriculture and health: Alliance or equityand rural development in the Americas”

2008 6


1978 6, 8



Ways orward Pa

A health system consists o more than the pyramid o publicly-owned acilities

that deliver personal health services. For example, mothers caring or sick

children, private health providers, vector-control campaigns, health insurance

organizations, and occupational health and saety legislation orm part o a healthsystem. Intersectoral action by health sta – or example to encourage a Ministry

o Education to promote emale education – is a well known determinant o betterhealth.

Growing recognition by the global community o the unacceptable scale and

severity o morbidity resulting rom NDs, coupled with changes in thinking

about how to prevent and control them, has provided an opportunity to strengthenhealth systems in the countries where these diseases have such detrimental eectson health and productivity. Summaries o the progress made in the developmentand practical application o this thinking, and the options it oers or using NDcontrol to strengthen health systems, are contained in two reports published by

WHO 12, 13).WHO advocates the prevention and control o NDs using the six components

(or core building blocks) that will strengthen the health systems o disease-

endemic countries 14). Te components are:

1. delivery o eective, sae, quality-assured health interventions to the

individuals and communities who need them, when and where they needthem, with the minimum waste o resources;

2. health workorce able to perorm responsively, airly and eciently to

achieve the best health outcomes possible, given the available resources

and circumstances (e.g. there should be enough trained and competent

sta evenly distributed to meet needs);

3. health inormation system to ensure the production, analysis, disseminationand use o reliable and timely inormation on health determinants, health-system perormance and health status;

4. ensure equitable access to essential medicines, vaccines and technologies

o assured quality, saety, ecacy and cost-eectiveness, and ensure theirscientifcally sound and cost-eective delivery;

5. establish a health fnancing system to raise adequate unds or health inways that ensure people have access to services and are protected rom

fnancial catastrophe or impoverishment associated with having to pay

or them;

6. leadership and governance to ensure that strategic policy rameworks existand are combined with eective oversight, coalition-building, regulation,attention to system-design and transparent accountability.



40


Macroparasites usually have complex lie-cycles involving intermediate and

reservoir hosts, and a tendency not to replicate in the defnitive human host. Somespecies o soil-transmitted helminths are an exception in that they do not requireintermediate hosts. ransmission may be (i) direct, through ingestion rom a

contaminated environment; (ii) direct, through skin penetration; (iii) indirect,through ingestion o an inected intermediate host or tissues o a reservoir host;

or (iv) indirect, through a vector serving as an intermediate host. Te inections

caused by macroparasites tend to be chronic rather than acute, and mortality ratesare considered low, given the millions o people experiencing disease.

Overcoming inections caused by a number o microparasites and

macroparasites is made more di cult because their survival and transmission

oen exploits a zoonotic component. Zoonotic inections are those in which

humans – through behaviour, culture or ood supply – have become incorporatedinto the transmission cycle o pathogens responsible or diseases in wild or

domesticated animals.

REFERENCE

1. Anderson RM, May RM. Inectious diseases o humans: dynamics and control . Oxord,

Oxord University Press, 1991.



42


Western Pacifc Region

Aer a major outbreak o dengue in the Western Pacifc Region in 1998, thenumber o reported cases remained at more than 150 000 during 2006–2007 (Figure5.1.3). Between 2000 and 2007, the 8 most aected Pacifc island countries andareas were French Polynesia 37 667 cases), Fiji 25 859), New Caledonia 14 270),the Cook Islands (7590), Palau (3146), Wallis and Futuna (2648), American Samoa(2310) and Kiribati (2143). From 1991 to 2004, 72 deaths were reported, most o which occurred during outbreaks in 1998, 2001 and 2003 in Fiji, French Polynesia,New Caledonia, Palau, the Solomon Islands and onga. All our serotypes (DEN-1, DEN-2, DEN-3 and DEN-4) have been reported in the Pacifc: A. aegypti is themain vector, and A. albopictus and A. polynesiensis are secondary vectors.

Fig. 5.1.1 Number o cases o dengue reported to WHO, 1995–2008

0

1.6

1995Year

N u m b e r o f c a s e s r e p o r t e d ( m i l l i o n s )

1.4

1.2

1

0.8

0.6

0.4

0.2

SEAR WPR AMR

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

AMR – The Americas / SEAR – South-East Asia / WPR – Western Pacifc



43

Neglected tropical diseases in the world today P

Region o the Americas

he an American ealth rganization has reported that interruption of

dengue transmission in the egion of the Americas resulted from the A. aegypti

eradication campaign in the region, conducted mainly during the 960s and

early 90s. ector surveillance and control measures were not sustained, and

subsequent resurgences of A. aegypti occurred, followed by dengue outbreaks in

the Caribbean and in Central and outh America. engue has since spread, with

outbreaks occurring every 35 years. he biggest outbreak – in 00 – generated

more than million reported cases. rom 200 to 2009, more than 30 countries inthe egion of the Americas notified a total of 6 66 950 cases of dengue. uring

the same period, there were 80 26 cases of dengue haemorrhagic fever and 2498

deaths, giving a C for dengue haemorrhagic fever of .38%. All four serotypes

of the virus circulate in the region and were identified simultaneously in 00

in 0 countries (Barbados, the Bolivarian epublic of enezuela, Colombia, the

ominican epublic, l alvador, uatemala, rench uyana, Mexico, eru and

uerto ico). ix countries (the Bolivarian epublic of enezuela, Brazil, Costa

ica, Colombia, onduras and Mexico) accounted for over more than 5% of all

cases in the region.

Eastern Mediterranean Region

n the astern Mediterranean egion, outbreaks of suspected dengue occurred

in akistan, audi Arabia, udan and emen during 005006 (1). n akistan,

a N-3 epidemic of dengue haemorrhagic fever was first reported in 005 (2).

ince then, outbreaks have increased in frequency and severity, reaching as far

north as the North-est rontier rovince in 008. emen is affected by the

increasing frequency and spread of epidemic dengue, and the number of cases



44


has risen since the N-3 epidemic in the estern al-udeidah governorate in

005. n 008, dengue affected the southern province of habwa. ince the first

death from dengue haemorrhagic fever in audi Arabia, in eddah in 993, the

country has reported three epidemics: a N- epidemic in 994 resulting in

469 cases of dengue, 3 cases of dengue haemorrhagic fever, cases of dengueshock syndrome and deaths; a N- epidemic in 006 resulting in 69 cases

of dengue, cases of dengue haemorrhagic fever, cases of dengue shock

syndrome and 6 deaths; and a N-3 epidemic in 008 resulting in 5 cases of

dengue, 9 cases of dengue haemorrhagic fever, 4 cases of dengue shock syndrome

and 4 deaths.

Arican Region

n the African egion, data from dengue surveillance remain sparse, and

cases and outbreaks are not reported to regularly. uring 984985, the

first major outbreak of N-3 was documented in emba, Mozambique. Most

patients experienced secondary infections and 2 deaths were attr ibuted to dengue

haemorrhagic fever. N-3 was identified again in a mixed outbreak caused by

N- and N-3 in omalia in 993 (3). ubsequent dengue outbreaks have

been reported from different countries, for example enegal (999, -2); -

3 cases were confirmed in Côte d’voire in 006 and 008 (3). n ctober 009,

a major outbreak of N-3 in Cape erde caused 5985 cases and 6 deaths (4).

Fig. 5.1.4 Distribution o countries or areas at risk o dengue transmission, worldwide, 2008

Countries or areas at risk o dengue transmission



46


In 1995, WHO developed a strategy or dengue prevention and control based

on (i) selective integrated vector control, with community and intersectoral

participation; (ii) active disease surveillance based on a strong health inormationsystem; iii) emergency preparedness; iv) capacity building and training; and v)

research into vector control. Successul programmes based on integrated vectormanagement and intersectoral collaboration are being implemented in Cuba,

Malaysia and Singapore. Sustaining such integrated vector management activities

and implementing them in other settings are the main challenges. Te integratedmanagement strategy or dengue prevention and control has been approved by

19 countries in the Region o the Americas. In 2009, WHO published revised

guidelines on dengue prevention and control, including case-management (7 ),

which recommend ollow-up training activities at regional and national levels.

Assessment

Outbreaks o dengue are increasing and spreading geographically. In 2008,

Member States o the South-East Asian and Western Pacifc Regions adopted

resolutions on dengue ever. In response to dengue epidemics, WHO recommendsselective vector control, active disease and vector surveillance and management

o severe cases in accordance with WHO’s guidelines (7 ). Sustained prevention

o dengue requires widespread vector control, environmental management and

possibly the development o a vaccine.

REFERENCES

1. Spread o dengue ever: the challen ges. DCD

Newsletter , 2005, 6:7–8 (also available at http.//www.

emro.who.int/pd/dcdnewsletter6.pd).

2. Bushra J et al. Dengue virus serotype 3, Karachi,

Pakistan. Emerging Inectious Diseases, 2007,

131):182–183.

3. Dengue in Arica: emergence o DENV-3, Côte

d’Ivoire, 2008. Weekly Epidemiological Record , 2009,

84:85–96.

4. Dengue ever, Cape Verde. Weekly Epidemiological

Record , 2009, 84:469.

5. he global burden o disease: 2004 update . Geneva,

World Health Organization, 2008.

6. Suayaja et al. Cost o dengue cases in eight countries in

the Americas and Asia: a prospective study. American

Journal o ropical Medicine and Hygiene, 2009,

80:846–855.

7. Dengue: guidelines or diagnosis, treatment, prevention

and control . Geneva, World Health Organization,

2009 (WHO/HM/ND/DEN/2009.1). © W

H O

Space-spraying activity outside a public building du ring a chikungunya outbreak in

Mauritius, 2006. Timely and proper space-spray application o insecticides is useul

in reducing transmission o dengue and chikungunya.



48


o human deaths caused by dog-transmitted rabies. By contrast, canine rabies

predominates in most o the developing countries o central and south America,Arica and Asia, where the greater burden o human rabies alls. More than 90%o cases o human rabies are transmitted by dogs (3); most deaths occur in Asia

and Arica 4).

Fig. 5.2.1 Distribution o risk levels or humans contracting rabies, worldwide, 2009

High risk Moderate risk

Low risk

No risk

Most Arican countries report the presence o human and dog rabies in all

or large parts o their territories. Inormation about the public-health impact o

wildlie rabies is limited. With some exceptions, data collected at the national

level are largely incomplete, notably or human rabies, and are oen based on

clinical observations rather than laboratory diagnosis (5). A number o Arican

countries have a national plan or controlling rabies through dog immunizationand population control, including post-exposure prophylaxis to prevent human

rabies. However dog vaccination coverage remains below the required threshold

o 70% and the availability o human vaccine is limited, especially in rural areas.argets or controlling and eliminating human and dog rabies at the regional levelhave not been established. Since early 2009, South Arica and the United Republico anzania have been working to eliminate human and dog rabies rom pilot

areas within 5 years.



49


In Latin American countries, national programmes or controlling dog rabies,which were initiated in 1983 and mainly based on mass immunization o dogs,have stopped dog-to-dog transmission and eliminated human rabies rom mosturban areas. Dog rabies is, however, stil l widespread in Cuba, the Dominican

Republic, El Salvador, Guatemala, Haiti and the Plurinational State o Bolivia.Rabies in vampire bats is widespread in Latin America; clusters o human deathsassociated with contact with bats are regularly reported in the Amazon orest,particularly in Brazil and Peru. Rabies in non-vampire bat species has emergedas a public-health problem in many Latin American countries since 2000. By 2003, the number o cases o dog-transmitted human rabies had allen by morethan 90% 6 ). Since then, ewer than 50 human rabies deaths have been reportedannually in the Region o the Americas, the majority still resulting rom contactwith dogs. In 2008, the 15th inter-American inter-ministerial meeting on healthand agriculture set a target or eliminating dog rabies in Latin America by 2012(7). In Canada and the United States, large programmes are under way to control

and eliminate rabies in wild carnivore hosts. Cases o human rabies (mostly transmitted by bats) remain rare in both countries.

In the Eastern Mediterranean Region, rabies virus circulates mostly in dogs,but the Islamic Republic o Iran, Oman and Saudi Arabia have reported theinvolvement o wolves, jackals and oxes. Te Islamic Republic o Iran and Sudanprovide high numbers o human post-exposure prophylaxis regimens per millioninhabitants to prevent the occurrence o human rabies, whereas in Aghanistan,Pakistan and Yemen these numbers are below those expected in countries whererabies is endemic 8).

In western Europe during the past 15 years, ox rabies has been eliminatedrom all aected countries ollowing more than 30 years o mass oral vaccinationcampaigns in oxes. In 2008, wildlie rabies in oxes and raccoon dogs was stillreported in many countries o eastern Europe, such as Belarus, Poland andUkraine, as well as in the Russian Federation. In south-eastern Europe, ox rabiesis present in Slovenia, and rabies occurs in oxes and dogs in Croatia, Bosniaand Herzegovina, Bulgaria, Romania, Montenegro and Serbia 9). Only Albania,the Former Yugoslav Republic o Macedonia and Greece reported the absence o rabies to WHO in 2008. Te Russian Federation and urkey reported signifcantnumbers o cases o dog rabies. In the Russian Federation, the dominant

epidemiological pattern in the north and south-western part o the country iswildlie rabies involving oxes and raccoon dogs; this is spreading eastwardsinto Siberia (10). In 2003, the Russian Federation launched a new wildlie rabies

vaccination project at its northern border with Finland and is planning a similarproject with Poland. In 2005, urkey launched a nationwide project to eliminatedog rabies with support rom the European Union. he rabies situation inAzerbaijan, ajikistan and Uzbekistan is not well known (11). In the EuropeanRegion, the number o human deaths rom rabies is estimated to be ewer than

100 cases annually, most o which involve dogs.



51


widespread use o post-exposure prophylaxis have signifcantly reduced the

number o human deaths rom rabies. Post-exposure prophylaxis is thought to

prevent more than 270 000 deaths in Asia and Arica 3).

Economic impactEstimating the economic impact o rabies should take into account the costs

o post-exposure prophylaxis, the control o rabies in dogs, losses to the livestock

industry and surveillance o the disease. Livestock losses can be signifcant, as

indicated by the results o a study carried out in Ethiopia, where it was estimated

that deaths among cattle caused by rabies cost the average household US$ 7.50

per year (17 ), equivalent to 7.5% o annual gross national income per capita. Te

estimated total expenditure or preventing and controlling rabies in Arica and

Asia is about US$ 585 million annually. Te greater part o the fnancial burden

alls on Asia, with 96% o total rabies expenditure occurring in the region. Te

breakdown o expenditure by cost category shows that the costs o post-exposuretreatment borne by patients orm the bulk o expenditure, accounting or nearly

hal o the total costs attributed to rabies. Tis expenditure as well as the requency o delivering post-exposure prophylaxis is expected to rise as all countries,

particularly by those replacing nerve-tissue vaccines by imported rabies vaccines

developed in cell cultures or embryonated eggs. In Asia and Arica, the cost o

human post-exposure treatment represents the main component o the economicburden o rabies; in Latin American countries such as Brazil and Mexico, the

cost o interventions aimed at controlling the disease in animals exceeds that o

post-exposure treatment. Te annual global expenditure or rabies prevention and

control exceeds US$ 1 billion, by WHO’s conservative assessment.

Prevention and control

Where rabies is a public-health issue, preventing the disease in humans dependson a combination o interventions including controlling rabies in both wild and

domestic animals, particularly dogs; providing pre-exposure immunization

to humans at occupational risk o contracting the disease; and on delivering

post-exposure prophylaxis to potentially exposed patients (18). Teoretical and

empirical studies show that immunizing 70% o the dog population is required

to stop dog-to-dog transmission (2, 19–21). Te level o success achieved by

vaccination programmes depends on knowledge o the ecology o the dogpopulation and the nature o human–dog interactions in the area.

Clinical inection in humans can be prevented by delivering prompt local

wound care and the timely administration o post-exposure treatment in the ormo rabies immunoglobulin and serial immunizations. Early post-exposure use o vaccines combined with proper wound treatment and administration o rabies

immunoglobulin is considered to be nearly 100% eective in preventing death,

even with high-risk exposure.



52


Reducing the burden o rabies and eliminating the disease in humans involve

coordinated eorts to procure and deliver sae and e cacious rabies vaccines

where they are most needed or preventive immunization in animals and pre-

exposure and post-exposure prophylaxis in humans. Awareness o preventive

measures is lacking among the general population, even in the most highly endemic regions, and many people exposed to the risk o rabies do not seek careat local health units where rabies biologicals may be available 16 ). Improving thedelivery o post-exposure treatment alone does not oer a long-term solution thatwill prevent deaths, especially among children 22). Countries are encouraged toinitiate measures that ensure coordination among all public sectors involved in

rabies control. Eorts should be coordinated among public sectors concerned withsurveillance and reporting, diagnosis, inormation campaigns, and vaccination o individuals and groups at risk o exposure 2).

AssessmentRabies remains a major public-health and economic concern or ministries o

health and agriculture in developing countries. Tis burden, which is increasingwith the continued demand or and consumption o sae and e cacious post-

exposure treatment, could be reduced and even eliminated through coordinatedinterventions aimed at controlling the disease in dogs. o achieve this goal,

pilot studies are in progress to demonstrate by 2013 the cost-eectiveness o

immunizing dogs in order to prevent rabies in humans.



53


REFERENCES

1. Rupprecht CE et al. Can rabies be eradicated? Developments in Biological Standardization

(Basel), 2008, 131:95–121.

2. Bishop GC. Canine rabies in South Arica. In: Bingham J, Bishop GC, King AA, eds.

Proceedings o the hird International Conerence o the Southern and East Arican Rabies

Group, Harare, 7–9 March 1995. Marcel Merieux Foundation, 1996:104–111.

3. WHO Expert Consultation on Rabies. Geneva, World Health Organization, 2005 (WHO

echnical Report Series, No. 931).

4. Knobel DL et al. Re-evaluating the burden o rabies in Arica and Asia. Bulletin o the

World Health Organization, 2005, 83:360–368.

5. Dodet B et al. Fighting rabies in Arica : the Arica Rabies Expert Bureau (AroREB),

Vaccine, 2008, 26:6295–6298.

6. Schneider MC et al. Current status o human rabies transmitted by dogs in Latin America.

Cadernos de Saúde, 2007, 23:2049–2063.

7. 15th inter-American meeting at ministerial level, on health and agriculture . Rio de Janeiro,

Brazil, 11–12 June 2008. World Health Organization/Pan American Health Organization

(RIMSA15/1, Rev. 2 (Sp.). 10 December 2007).

8. Seimenis A. he rabies situation in the Middle East. In: Proceedings o a joint OIE/WHO/

EU international conerence “owards the elimination o rabies in Eurasia”, Paris, France,

27–30 May 2007. Developments in Biologicals, 2008, 131:43–53.

9. Wandeler AI. he rabies situation in Western Europe. In: Proceedings o a joint OIE/WHO/EU international conerence “owards the elimination o rabies in Eurasia”, Paris,

France, 27–30 May 2007. Developments in Biologicals, 2008, 131:19–26.

10. Matouch O. he rabies situation in Eastern Europe. In: proceedings o a joint OIE/WHO/



11. Gruzdev KN. he rabies situation in Central Asia. In: Proceedings o a joint OIE/WHO/



Mass vaccination campaign o dogs,

United Republic o Tanzania.

Dogs continue to be the main carrier

o rabies, particularly in Arica and

Asia. Humans most oten become

inected through the bite or scratch o

an inected dog. Mass vaccination o

pets helps to prevent occurrence o

human rabies.

© S

a r a h C l e a v e l a n d



54


12. Sudarshan M et al . Assessing the burden o human rabies in India: results o a national

multi-center epidemiological survey. International Journal o Inectious Diseases, 2007, 11:

29–35.

13. Windiyaningsih C et al . he rabies epidemic on Flores Island, Indonesia (1998–2003).

Journal o the Medical Association o hailand , 2004, 87:1389–1393.

14. Fu ZF. he rabies situation in ar East Asia. In: Proceedings o a joint OIE/WHO/EU

international conerence “owards the elimination o rabies in Eurasia”, Paris, France,


15. Call or action: towards the elimination o rabies in the ASEAN Member States and the Plus

hree Countries. Jakarta, Association o Southeast Asian Nations.

16. Hampson K et al. Rabies exposures, post-exposure prophylaxis and deaths in a region o

endemic canine rabies. PLoS Neglected ropical Diseases, 2008, 2(11):e339.

17. Laurenson MK et al. Rabies as a threat to the Ethiopian wol (Canis simensis). In: Kitala

P et al., eds. Proceedings o 5th meeting o the Southern and Eastern Arican Rabies Group

(SEARG), Nairobi Kenya 4–6 March 1997 . Lyon, Fondation Marcel Merieux, 1998:97–103.

18. Rabies vaccines: WHO position paper. Weekly Epidemiological Record , 2010, 85: 309–320.

19. Kitala PM et al. Comparison o vaccination strategies or the control o dog rabies in

Machakos District, Kenya. Epidemiology and Inection, 2002, 129:215–222.

20. Cleaveland S et al. A dog rabies vaccination campaign in rural Arica: impact on the

incidence o dog rabies and human dog-bite injuries. Vaccine, 2003, 21:1965–1973.

21. Zinsstag J et al ransmission dynamics and economics o rabies control in dogs and

humans in an Arican city. PNAS, 2009, 106:14996–15001.

22. Cleaveland S et al. Canine vaccination-providing broader beneits or disease control.

Veterinary Microbiology, 2006, 117:53–50.



55


5.3 Trachoma

Abstract

In 57 countries where trachoma is endemic mil lions o people have irreversible visual impairment and blindness caused by the disease, and more than 40 millionpeople are in need o treatment. rachoma is caused by an obligate intracellular

microorganism (Chlamydia trachomatis), which is transmitted through contactwith eye and nose discharge rom inected people, particularly children, and,possibly, by eye-seeking ies. Te economic cost o trachoma in terms o lost

productivity is estimated at US$ 2.9 billion annually. Activities to control thedisease should adopt the SAFE strategy – that is, lid surgery (S), antibiotics to treatthe community pool o inection (A), acial cleanliness (F) and environmentalimprovement E).

Description

rachoma is responsible or approximately 3% o the world’s blindness (1).

Environmental risk actors inuencing transmission o the disease include poorhygiene, crowded households, water shortage and inadequate latrines. Aer yearso repeated inection, the inside o the eyelid may become scarred so severely thatit turns inward and the lashes rub the eyeball (trichiasis) and scar the cornea. Leuntreated, this condition – called “blinding trachoma” – leads to the ormation o irreversible corneal opacities and blindness.

In areas where trachoma is endemic, the average age o acquisition o the frstepisode o C. trachomatis inection is related to the prevailing level o inection

in the community: in hyperendemic settings, inection may be acquired in early

inancy. Inection is usually acquired through living in close proximity to an

inected person, and the amily is the principal unit or transmission 2).

Distribution

Blinding trachoma is hyperendemic in many o the poorest and most remoterural areas in 57 countries o Arica, Asia, Central and South America, Australiaand the Middle-East Figure 5.3.1) 3).

Roughly hal the global burden o active trachoma is concentrated in 5 countriesEthiopia, Guinea, India, Nigeria and Sudan), and that o trichiasis in 4 countries(China, Ethiopia, Nigeria and Sudan). Overall, Arica is the most aectedcontinent: 27.8 million cases o active trachoma (68.5% o all cases globally)

and 3.8 million cases o trichiasis (46.6% o all) occur in 28/46 countries in theArican Region. Te highest prevalences o active trachoma have been reported

rom Ethiopia and Sudan, where the inection oen occurs in more than 50% o

children younger than 10 years; trichiasis is ound in up to 19% o adults.



57



rachoma control programmes in endemic countries are being implementedat a dierent pace. In 1998, the World Health Assembly resolved to eliminateblinding trachoma as a public-health problem by the year 2020 (11). o this end,

control activities have been instituted through primary health-care approachesthat ollow the SAFE strategy, which consists o lid surgery S), antibiotics to treatthe community pool o inection (A), acial cleanliness (F) and environmentalimprovement E).

here is evidence to support the eectiveness o each component o theSAFE strategy (12). Problems with surgical outcomes may include high rates o trichiasis recurrence reported under operational conditions (13). Te overall cost-eectiveness o implementing the SAFE strategy has been estimated at US$ 54 percase o visual impairment prevented 14, 15).

Various countries have set target dates or the elimination o blinding trachoma.

Member States and partners have agreed to accelerate implementation o theSAFE strategy in order to reect the planned progression o elimination activitiesand achieve the relevant elimination targets (Figure 5.3.2). It is estimated that,during 2008–2012, about 1.7 billion doses o azithromycin and 19 million tubeso tetracycline eye ointment will be required to treat 60% o the target populationswith preventive chemotherapy where trachoma is endemic; the cost is equivalentto approximately US$ 0.4 billion.

Fig. 5.3.2 Target dates set by Member States or eliminatingblinding trachoma

2005-2008 2010 2011

Gambia

2012 2014 2015 2020

Achieved elimination

Not confrmed in trachoma

data orm 2010

Cameroon

Egypt

Ethiopia

Lao People'sDemocraticRepublic

Malawi

South Sudan

United Republico Tanzania

Uganda

Yemen

Zambia

Brazil

Burkina Faso

Burundi

Cambodia

Central AricanRepublic

DemocraticRepublic o the

Congo

Guinea

Kenya

Mali

Niger

Pakistan

SenegalSudan

Mauritania

Nepal

Guinea-Bissau

Djibouti

Eritrea

Nigeria

Viet Nam

China

Ghana

Myanmar

Morocco

Iran (IslamicRepublic o)

Oman

Eritrea: 2011=>2012Mauritania: 2012=>2014Nepal: 2015=>2014Nigeria: 2015=>2012

Assessment

Implementation o the SAFE strategy should lead to the elimination o blindingtrachoma (trichiasis) by 2020 in accordance with World Health Assembly resolution WHA51.11 adopted in 1998. Based on inormation reported to WHO,in 2008 about 60% o the population in need received preventive chemotherapy



58


using antibiotics and about 45% received surgical care. Te Islamic Republic

o Iran, Morocco and Oman have reported reaching their elimination targets,

but the global prevalence o blinding trachoma still must be reduced rom the

estimated 8 million cases o trichiasis 3).

REFERENCES

1. Resniko S et al. Global magnitude o visual impairment caused by uncorrected reractive errors in 2004. Bulletin o the World Health

Organization , 2008, 86:63–70.2. Barenanger J. Studies on the role o the amily unit in the transmission

o trachoma. American Journal o ropical Medicine and Hygiene , 1975,24:509–515.

3. Mariotti SP, Pascolini D, Rose-Nussbaumer J. rachoma: globalmagnitude o a preventable cause o blindness. British Journal o

Ophthalmology, 2009, 93:563–568.4. Frick KD et al. richiasis and disability in a trachoma-endemic area o

anzania. Archives o Ophthalmology, 2001, 119:1839–1844.5. Kirkwood B et al. Relationships between mortality, visual acuity

and microilarial load in the area o the Onchocerciasis ControlProgramme. ransactions o the Royal Society o ropical Medicine

and Hygiene, 1983, 77:862–868.6. aylor HR et al. Increase in mortal ity associated with blindness in

rural Arica. Bulletin o the World Health Organization, 1991, 69:335–338.

7. Bailey R et al. he duration o human ocular Chlamydia trachomatis

inection is age dependent. Epidemiology and Inection, 1999, 123:479–486.

8. West SK et al. he epidemiology o trachoma in central anzania.International Journal o Epidemiology, 1991, 20:1088–1092.

9. Courtright P et al. rachoma and blindness in the Nile Delta:current patterns and projections or the uture in the rural Egyptianpopulation. British Journal o Ophthalmology, 1989, 73:536–540.

10. Frick KD, Hanson CL, Jacobson GA. Global burden o trachoma andeconomics o the disease. American Journal o ropical Medicine and

Hygiene, 2003, 69:1–10.11. Global elimination o blinding trachoma (Resolution WHA51.11).

[Adopted by the Fity-irst World Health Assembly on 16 May 1998.]Geneva, World Health Organization, 1998.

12. Sumamo E et al. he Cochrane library and trachoma: an overview o reviews. Evidence-Based Child Health, 2007, 2:943–964.

13. West ES et al. Risk actors or postsurgical trichiasis recurrence in atrachoma-endemic area. Investigative Ophthalmology & Visual Science,2005, 46: 447–453.

14. Evans G et al. Cost-eectiveness and cost utility o preventingtachomatous visual impairment: lessons rom 30 years o trachomacontrol in Burma. British Journal o Ophthalmology, 1996, 80:880–889.

15. Baltussen RM et al. Cost-eectiveness o trachoma control in seven

world regions. Ophthalmic Epidemiology, 2005, 12:91–101.

© W

H O

Masai village, United Republic o Tanzania. Despite surgery,

Mzurisana (seen leaning against the tree) still cannot see well

enough to make the necklaces that she once sold as her main

source o income. She survives on the little money she earns by

selling milk and borrowing ood rom neighbours. She cannot

aord to send her children to school. Mzurisana’s plight could have

been prevented by better community education about eye health

and more accessible health care services.



61


MorbidityTe main problems caused by Buruli ulcer are the long periods needed or

healing, which include hospitalization, and contractures resulting rom healingin late disease, especially when lesions cross joints and treatment is inadequate.

Some studies have estimated that about 25% o healed cases have some extent o

disability 7 ). Other studies have arrived at higher percentages, depending on theextent o early-detection activities taking place in the study area – that is, i thereare ewer detection activities then the proportion o those who become disabled

will be higher. About 55% o cases occur in children, and there is no dierence

between males and emales as ar as the requency o inection is concerned (8).Te ew cases o death in patients are related to secondary causes (sepsis and

tetanus).

Economic impactBuruli ulcer imposes an economic burden on aected households and on health

systems that are involved in diagnosis and treatment. In Ghana during 2001–2003,the median annual total cost o the disease to a household, by stage o disease,ranged rom US$ 76.20 16% o a work year) per patient with a lesion to US$ 42889% o a work year) per patient who had undergone amputation 9). Te averagecost o treating a case was estimated to be US$ 780 per patient during 1994–1996,an amount that ar exceeded per capita government spending on health (7 ). In

Australia during 1997–1998, the average cost o diagnosing Buruli ulcer andtreating a patient was AUS$ 14 608 (10), an amount approximately seven timesgreater than the average national health expenditure per person AUS$ 2557). Ina study conducted in 2008 in Cameroon 11), hospitalization costs accounted or25% o households’ yearly earnings; median total costs o hospital treatment were€126.70. In addition to preventing disabilities, early detection and treatment o

cases are thereore economical and should be widely promoted.

1400

1 9 9 0

Year

N u m b e r o f n e w c a s e s r e p o r

t e d

Fig. 5.4.3 Number o new cases o Buruli ulcer reported to WHO,Benin, 1989–2009

0

1 9 8 9

1 9 9 1 1 9

9 2 1 9

9 3 1 9

9 4 1 9

9 5 1 9

9 6 1 9

9 7 1 9

9 8 1 9

9 9 2 0

0 0 2 0

0 1 2 0

0 2 2 0

0 3 2 0

0 4 2 0

0 5 2 0

0 6 2 0

0 7 2 0

0 8 2 0

0 9

1200

1000

800

600

400

200



62


Prevention and controlIn many countries, activities to control the disease through early case-detection

and treatment are restricted by limited resources. reatment acilities are limitedin aected areas, but the move towards decentralized delivery o antibiotic therapy should increase coverage. Te cost o interventions includes that or implementingearly detection and health education eorts at the community level, training

health workers, providing riampicin and streptomycin, supporting surgical

treatment or complicated cases, and rehabilitating those with deormities.

AssessmentResolution WHA57.1 adopted by the World Health Assembly in 2004 urges

endemic countries to intensiy control activities and accelerate research. Te

priority is to improve early detection and case-management in the absence o a vaccine. Basic research is needed to understand the biology and epidemiology o

the causative agent o this emerging disease.

© N

a t i o n a l B u r u l i U l c e r C o n t r o l P r o g r a m m e ,

G h a n a

Child receiving treatment

at Agogo hospital, Ghana.

Early detection o Buruli

ulcer disease is crucial to

prevent complications and

surgery.



64


5.5 Endemic treponematoses

AbstractEndemic treponematoses, which comprise yaws, endemic syphilis (bejel)

and pinta, are caused by bacteria o the genus Treponema. By the early 1970s,

prevalence o the diseases had been reduced rom 50 million to 2.5 million cases

ollowing the widespread use o long-lasting injectable penicillin. Tis progress

was not maintained.

Description

Te endemic treponematoses are a group o chronic bacterial inections causedby treponemes (1). Yaws is caused by Treponema pallidum pertenue, endemic

syphilis by T. pallidum endemicum, and pinta by T. pallidum carateum. Tese

organisms are morphologically and serologically indistinguishable rom the

organism that causes venereal syphilis (T. pallidum pallidum). Yaws is the most

prevalent disease. Endemic treponematoses cause disfgurement and disability i

le untreated. One o the major success stories in public health was the treatment

campaign led by WHO and UNICEF in the 1950s and 1960s, which reached 50

million individuals in 46 countries, and reduced the global burden o the endemictreponematoses to 2.5 million cases by the end o the campaigns in the early 1970s(2, 3). Penicillin was responsible or this achievement. Te absence o continued

surveillance in the remaining endemic countries allowed treponematoses to

persist; their resurgence in the late 1970s led to the adoption by the World Health

Assembly o resolution WHA31.58 in 1978, which aimed to implement integratedtreponematoses control programmes and place particular emphasis on active

surveillance to interrupt transmission o the diseases at the earliest possible time

in the areas where they are endemic and to prevent their recurrence in areas romwhich they have been eliminated or where they have never been endemic. Tis

was ollowed by renewed control eorts in west Arica in the early 1980s, but thesewere not sustained.

Yaws and endemic syphilis aect the skin and bone, while pinta is confned to

the skin. Poor personal hygiene and overcrowding acilitate their spread. Clinicalmaniestations are modifed by climate, season and the level o endemicity in the

aected geographical area. Diagnosis oen relies on clinical fndings. Serological

tests available or diagnosis are: the rapid plasmin reagin test, the venereal

disease research laboratory nontreponemal test, the treponemal pallidum

haemagglutination assay and the uorescent treponemal antibody absorption test.Te results rom these tests are helpul but should be interpreted in the context o

clinical fndings, the age o the patient and the endemicity o the area.



65


Distribution

he global extent o endemic treponematoses remains unknown.

reponematoses have been largely eliminated or signifcantly reduced in many

o the 46 countries that were endemic in the 1950s. Relatively ew countries wereendemic or these diseases in the 1990s; their status in 2008 is shown in Figure

5.5.1. Te last estimate by WHO in 1995 yielded a global prevalence o 2.5 millioncases, o which 460 000 were considered inectious (3). Most cases were in the

Arican Region. Since the early 1990s, there has been no ormal reporting o casesto WHO, and programmes to control these diseases have largely disappeared.

Only fve countries maintain some activities to control yaws. Since 2004, India

has reported zero cases aer intense eorts to eliminate the disease (4). Indonesia,while remaining the major endemic area in the South-East Asia Region, still

maintains its control programme (5). Papua New Guinea occasionally reports

data through the routine surveillance system and remains the major endemic areain the Western Pacifc Region.

Fig. 5.5.1 Distribution o endemic treponematoses, worldwide, 2008

≥10 000

Number o reported cases, 2008

1 000–9 999

<1 000

0 cases reported

Previously reported cases

No cases reported

Ghana has a signiicant number o yaws cases and maintains its control

programme. In Congo, cases o yaws occur among the pygmy population in the

regions o Likouala, Lekoumou and Sangha, and a survey in 2009 identifed 646



66


clinical cases (6 ). In 2008, a survey carried out in Lomie Health District in the

Eastern province o Cameroon identifed 167 clinical cases among the pygmy

population (personal communication, national coordinator or Leprosy, Buruli

ulcer and yaws, 2009). Cases have been reported in Côte d’Ivoire (7 ) and the

Democratic Republic o the Congo 8).

Tere are no clear patterns in the number o cases reported, such as that seen

in the obvious trend in Indonesia (Figure 5.5.2). As renewed interest increases andactivities intensiy in aected countries as part o ND control programmes, theull extent o endemic treponematoses, including trends over time, should becomeapparent.

10 000

2001

Year

N u m b e r o f n e w

c a s e s r e p o r t e d

Fig. 5.5.2 Number o new cases o yaws reported in Indonesia,2001–2009

0

9 000

8 000

7 000

6 000

5 000

4 000

3 000

2 000

1 000

2002 2003 2004 2005 2006 2007 2008 2009

Morbidity

Ulcerative cases may become inected and can lead to severe secondary bacterialinection including tetanus. Long-term complications o yaws arising 5 or moreyears later) occur in 10% o untreated cases, leading to disfgurement o the ace

and legs. Yaws most requently aects children, and inection peaks in those aged2–10 years (9). O new cases, 75% occur in children younger than 14 years. For

pinta, the age range is 10–30 years. Yaws aects boys more oen than girls; inendemic syphilis and pinta there is no dierence between males and emales in

the number aected.

Tere are no estimates o the economic impact o endemic treponematoses.

Since these diseases respond well to penicillin, it is unlikely that their long-term

economic impact would be considerable, although a ew cases o disfguring

complications may have a social rather than an economic impact. Motivation oraction against endemic treponematoses is based on humanitarian reasons: since



67


eective and inexpensive treatment is available, the persistence o treponematosesis medically and socially unacceptable. Tere is no reported mortality associatedwith endemic treponematoses.

Prevention and controlControl and treatment policies developed primarily or yaws decades ago are

still applicable or all the endemic treponematoses today: where prevalence is morethan 10%, the entire population should be treated; where prevalence is 5–10%, allactive cases, children aged younger than 14 years and obvious contacts should betreated; where prevalence is less than 5%, all active cases, household members andobvious contacts should be treated. reatment o these inections involves a singleinjection o long-acting benzathine penicillin. Te recommended single doses are600 000 units or children younger than 6 years, 1.2 million units or those aged

6–14 years and 2.4 million units or those older than 14 years 1).

In 2007, WHO launched a renewed attempt to eliminate yaws and related

diseases with a strategy or their control and eventual elimination based on

our components: (i) identifcation o the population at risk o inection; (ii)

case-fnding (active and passive); (iii) treatment o cases and contacts; and (iv)

surveillance using standardized recording and reporting systems) 2).

Assessment

Complete interruption o transmission as envisaged by resolution WHA31.58

adopted in 1978 has not been attained because the control programmes stopped.

Renewal o prevention and control activities requires active case-fnding andimproved treatment, preerably using non-injectable antibiotics 10–12).



69


5.6 Leprosy (Hansen disease)

AbstractO 122 countries considered to be endemic or leprosy, 119 have eliminated

the disease as a public-health problem (defned as achieving a prevalence o less

than 1 case/10 000 population). Te 213 000 cases reported are confned mostly

to 17 countries reporting more than 1000 cases annually. Tis fgure reects a

reduction o more than 90% in the number o cases detected globally since 1985,

mainly as a result o timely case-fnding and multidrug therapy, which have also

prevented disabilities caused by leprosy in 1–2 million people. ransmission o

the bacterium Mycobacterium leprae) continues in limited geographical areas in

several countries that have reached the national elimination target.

Description

Leprosy results rom a slowly progressive bacterial inection with

Mycobacterium leprae. Te disease mainly aects the skin, peripheral nerves,

lining o the upper respiratory tract, eyes and other organs. Leprosy aects peopleo all ages and both sexes. Te standard treatment or leprosy – multidrug therapy (a combination o riampicin, dapsone and cloazimine) – was recommended in

1981 by a WHO Study Group on chemotherapy or leprosy (1). Multidrug therapy,which replaced dapsone monotherapy, prevents the development o disabilities

by providing an early cure, and it prevents the emergence o drug resistance (2).

Le untreated, leprosy causes permanent damage to the skin, nerves, limbs and

eyes. For centuries, people suering rom leprosy were subject to discrimination,

stigmatization and exclusion.

Leprosy is not highly inectious because most people have natural immunity. Inaddition, once patients start multidrug therapy they are no longer inectious. Te

exact mode o transmission is not known but probably occurs through droplets

rom the nose and mouth during close and requent contact with untreated cases.Diagnosis commonly relies on clinical signs and symptoms. Only in rare instances

are laboratory and other investigations needed to confrm a diagnosis.

Distribution and trends

Since 1985, the reported prevalence o leprosy has been reduced by more than

90%, and more than 15 million patients have been cured (Figure 5.6.1). o date,

119/122 countries considered to be endemic or leprosy have eliminated the diseaseas a public-health problem Table 5.6.1).



70


n 009, a total of countries or territories reported on leprosy to :

3 from the African egion, 5 from the egion of the Americas, 0 from the

outh-ast Asia egion, from the astern Mediterranean egion and 33 from

the estern acific egion. At the beginning of 009, there were 3 036 casesregistered globally (3).

Fig. 5.6.1 Leprosy prevalence rates, data reported to WHO as o January 2009

>2

Prevalence rates (per 10 000 population)

1.0–2.0

<1

0 cases reported

No data available

Table 5.6.1 Trends in the detection o new leprosy cases, by WHO region (excluding the European Region),2002–2008 ( 3 )

WHO region

Number o new cases detected annually

2002 2003 2004 2005 2006 2007 2008

Arican 48 248 47 006 46 918 45 179 34 480 34 468 29 814

Americas 39 939 52 435 52 662 41 952 47 612 42 135 41 891

South-East Asia 520 632 405 147 298 603 201 635 174 118 171 576 167 505Eastern

Mediterranean4 665 3 940 3 392 3 133 3 261 4 091 3 938

Western Pacifc 7 154 6 190 6 216 7 137 6 190 5 863 5 859

Total 620 638 514 718 407 791 299 036 265 661 258 133 249 007

During 2008, only 17 countries reported more than 1000 new cases, accountingor 94% o the new cases detected globally.



73


Economic impact

Costs associated with control include those o case detection, treatment,

prevention o disability and rehabilitation. As case-detection rates decrease, the

average cost o detecting a case increases. Many leprosy control programmesnow rely on voluntary case-fnding supported by inormation, education and

communication activities to raise and maintain awareness o the early signs

and symptoms o leprosy. Costs o diagnosis and treatment have allen steadily,

and diagnosis by clinical examination only is now recommended. Te average

cost o fnding, treating, preventing disability in and rehabilitating a new case

ranges rom US$ 76 to US$ 264 6 ). Te cost per DALY o detecting and treatinga new case o leprosy is estimated to be US$ 38; or patients needing treatment orreactions and ulcers the cost per DALY is estimated to be US$ 7; or those needingootwear and sel-care education the cost is estimated at US$ 75; and or those

requiring reconstructive surgery it is US$ 110.

Data on the economic eect o leprosy at the national level are not available,

but leprosy aects the economically active, and the incidence peaks among thoseaged 10–20 years and 30–50 years. Studies o the impact o leprosy on productivity show that deormity rom leprosy reduces the chances o obtaining employment

and reduces household income and expenditure on ood 7 , 8).


Te dramatic impact o multidrug therapy led to the adoption in 1991 by theWorld Health Assembly o resolution WHA44.9 to eliminate leprosy as a public-health problem by 2000. Elimination is defned as reducing the prevalence o thedisease to less than 1 case/10 000 people. Te strategy to eliminate leprosy as a

public-health problem has two elements: (i) improving access to early diagnosis

by integrating leprosy control services into existing public-health services; and

(ii) providing ree multidrug therapy. Te early detection o cases has reduced therisk o deormities and disabilities, ensuring that people aected by leprosy can

lead normal lives with dignity.

Te scaling up o access to multidrug therapy took place during several distinctphases Table 5.6.2). Te slow uptake in the frst two phases was due to the highercost o multidrug therapy compared with dapsone monotherapy. Additionally,

sta providing leprosy control services needed to be retrained and reorganized

to provide monthly treatment instead o the earlier regimen o lielong treatmentprovided annually. Te provision o ree multidrug therapy or all patients was

the turning point in the eort against leprosy. With assured supplies o multidrugtherapy, health ministries in endemic countries scaled up access to diagnosis andtreatment.



74


Assessment

Early case detection and multidrug therapy will remain the key elements o

the leprosy-control strategy in the oreseeable uture. Tere is a need to maintain

the ree supply o medicines used or multidrug therapy. Te goal o eliminatingleprosy as a public-health problem has been shown to be attainable. Resource-

constrained countries have achieved that goal.

REFERENCES

1. Chemotherapy o leprosy or control programmes: report o a WHO Study Group. Geneva,

World Health Organization, 1982 (WHO echnical Report Series, No. 675).

2. Risk o relapse in leprosy. Geneva, World Health Organization, 1994 (WHO/CD/

LEP/94.1).

3. Leprosy: global situation. Weekly Epidemiological Record , 2009, 84:333–340.

4. Doull J A et al. he incidence o leprosy in Cordova and alisay, Cebu, Philippines.

International Journal o Leprosy, 1942, 10:107–131.

5. Leprosy disabil ities: magnitude o the problem. Weekly Epidemiological Record , 1995,

70:269–275.6. Jan HF et al. ropical diseases targeted or elimination: Chagas disease, lymphatic

ilariasis , onchocerciasis, and leprosy. In: Jamison D et al., eds. Disease control priorities

in developing countries, 2nd ed. New York, Oxord University Press, 2006:433–450.

7. Diey B et al. he eect o leprosy-induced deormity on the nutritional status o

index cases and their household members in rural South India: a socioeconomic

perspective. European Journal o Clinical Nutrition, 2000, 54(8):643–649.

8. Kopparty SN. Problems, acceptance, and social inequality: a study o the deormed

leprosy patients and their amil ies. Leprosy Review, 1995, 66(3):239–249.

© W

H O

Students discussing

leprosy at school

in India. Access to

inormation, diagnosis

and treatment with

multidrug therapy

(MDT) remain key

elements o WHO’s

drive to eliminate

leprosy.



75


5.7 Chagas disease (American trypanosomiasis)

Abstract

Chagas disease continues to persist in the Region o the Americas, but the

estimated number o inected people has allen rom approximately 20 million

in 1981 to around 10 million in 2009. Te risk o transmission has been reduced

by introducing vector-control measures and saer blood transusions in Latin

America. Population mobility has carried the disease to regions where the diseasewas previously unknown.

Description

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi.

Inection mainly occurs through contact with the aeces o a triatomine bug,

which deecates aer sucking blood at night. Te insect resides in crevices in

the walls and roos o poorly constructed houses, usually in rural and periurbanareas throughout Latin America. Te parasite is transmitted when a person

inadvertently enables the parasite-contaminated aeces to make contact with any break in the skin (including the bite), the eyes or mouth (1). Other modes o

transmission include transusion o inected blood (2), oral transmission throughcontaminated ood (3), vertical transmission (4) and organ transplantation (5). Upto 30% o patients will develop heart damage, and up to 10% will develop damageto their oesophagus, colon or autonomic nervous system, or all o these, in the latechronic phase o the disease. Patients ultimately die, usually rom sudden death

caused by arrhythmias; this oen occurs in early adulthood.

Distribution

About 10 million people worldwide are estimated to be inected with T. cruzi,

mostly in the endemic areas o 21 Latin American countries: Argentina, Belize,

the Bolivarian Republic o Venezuela, Brazil, Chile, Colombia, Costa Rica,

Ecuador, El Salvador, French Guyana, Guatemala, Guyana, Honduras, Mexico,

Nicaragua, Panama, Paraguay, Peru, the Plurinational State o Bolivia, Surinameand Uruguay 6 ) Figure 5.7.1).



76


For thousands o years, Chagas disease was known only in the Region o

the Americas, mainly in Latin America, where it has been endemic (7 ). In past

decades, it has been increasingly detected in other non-endemic countries in theRegion o the Americas Canada and the United States o America), the WesternPacifc Region (mainly Australia and Japan) and the European Region (mainly

in Belgium, France, Italy, Spain, Switzerland and the United Kingdom, but also

in Austria, Croatia, Denmark, Germany, Luxembourg, the Netherlands, Norway,Portugal, Romania and Sweden). Te presence o Chagas disease outside Latin

America is the result o population mobility, notably migration, but cases have

been reported among travellers returning rom Latin America and even in adoptedchildren 8). Subsequent transmission occurs through transusion or vertical andtransplantation routes 9).

Morbidity

Chagas disease maniests in two phases. Initially, there is an acute phase,

lasting or about 2 months, with a high parasitaemia in the blood. Most cases areasymptomatic or present nonspecifc symptoms but, depending on the entrance

Fig. 5.7.1 Distribution o cases o Trypanosoma cruzi inection, based on ofcial estimatesand status o vector transmission, worldwide, 2006–2009

Countries without vector transmission

Status o vector transmission

Countries with accidental vector transmission

Countries with ongoing vector transmission

<1 000

Estimated number o cases

1 000–99 999

100 000– 999 999

≥1 000 000

No ofcially estimated cases



77


point o the parasite into the body, the frst sign can be a skin lesion chagoma) orpurplish swelling o one eyelid (Romaña sign) with locally enlarged lymph glandsand ever lasting or several weeks. Other symptoms may include headache, pallor,muscle pain, di culty in breathing, swelling o the legs or ace, abdominal pain,

cough, liver enlargement, rash, painul nodules, spleen enlargement, generalizedbody swelling, diarrhoea, multiple swollen lymph glands, heart inammation

(with chest pain and even heart ailure) and, less requently, meningoencephalitis(with seizures and even paralysis). Te disease may be more severe in children

younger than 2 years, the elderly, the immunosuppressed or in individuals

inected with a high number o parasites, such as seen in oodborne outbreaks

(oral transmission). In people with AIDS, meningoencephalitis is the most

requent maniestation.

Te acute phase is ollowed by the chronic phase, with parasites hidden in targettissues, especially in the heart and digestive muscles. During this phase, dierentclinical orms may be observed: (i) the indeterminate or asymptomatic orm –

the most requent orm – is typically ound immediately aer the acute phase

and is lielong in most patients; (ii) the cardiac orm occurs in up to 30% o the

patients, with disorders o the heart’s electrical conduction system, arrhythmia,

heart-muscle disorder, heart ailure and embolisms; (iii) the orm o digestive

lesions (enlargement o the oesophagus and the colon) has been observed south

o the Amazon basin; and (iv) a mixed orm (cardiac plus digestive) that aects upto 10% o patients 10). More than 10 000 deaths are estimated to occur annually rom Chagas disease.

In areas with domiciliary vector transmission, typically children younger than5 years are inected. In areas without domiciliary transmission, the inection is

detected at older ages, and is usually related to agricultural, fshing or hunting

activities that provide greater exposure to wildlie vectors. In general, there is

no gender predominance in Chagas disease, but local variations exist dependingon exposure to dierent routes o transmission. Te incapacitating eects and

mortality o Chagas disease have been one o the biggest public-health problems

in Latin America. According to a published study 11), the 10-year mortality ratemay range rom 9% to 85%, depending on the cardiac damage.

Economic impactTe cost o treating Chagas disease is substantial, even though many people

are not receiving appropriate care. A recent study 12) in Colombia estimated anaverage expected annual cost per patient with chronic Chagas disease o US$ 1028.On average, the estimated lietime cost o treating a patient with chronic Chagasdisease in Colombia is US$ 11 619. Without taking into account the number

o inected patients who have not developed chronic alterations (these patients

are also a burden on the health-care system), the same study calculated that



78


the economic burden o the medical care o all patients who developed chronic

conditions would be around US$ 267 million per year. aking into account the

dwellings that should be prioritized because o the risk o vector transmission,

spraying activities would cost nearly US$ 5 million, or around 2% o the expectedannual expenditure on health care. Tese rough estimations seem to confrm

the potential o accruing not only economic savings but also, more importantly,

avoiding disability and suering.


here have been national and international successes in parasite and vector

control as a result of the outhern Cone nitiative, the Central American

nitiative, the Andean act nitiative and the Amazonian nitiative, all of which

were technically supported by the an American ealth rganization. hese

multinational initiatives have led to substantial reductions in transmission by

Triatoma infestans, the principal vector in the outhern Cone countries (Argentina,

Brazil, Chile, araguay, the lurinational tate of Bolivia and ruguay), and

by Rhodnius prolixus in Central America. n addition, the risk of transmission

by blood transfusion has been substantially reduced throughout atin America.

hese advances have been achieved because of the commitment from Member

tates where the disease is endemic and the strength of their research and control

organizations, which benefit from the support of international partners (13).

ustaining and consolidating the advances made in controlling the disease,

including those made in areas of low endemicity, will depend on retaining political

interest and public-health resources. urveillance and control programmes must

be able to adapt to new epidemiological scenarios, rather than continue the same

effort or believe that the current success will be permanent (14). urveillance will

be important to detect the emergence of disease in regions previously considered

to be free of it, such as the Amazon basin, where transmission would involve

wildlife rather than domestic vectors and may include local microepidemics of

orally transmitted disease (15). urveillance will be equally important to detect

the re-emergence of disease in regions where control had been in progress,

in areas such as the Chaco region of Argentina and the lurinational tate of

Bolivia, but surveillance may become more complicated owing to extensive extra-

domestic populations of the main vectors and focalized resistance to pyrethroid

insecticides (16 ).

he movement of Chagas disease to areas previously considered non-endemic,

resulting from increasing population mobility between atin America and the

rest of the world, represents a serious public-health challenge. he appearance

of Chagas disease in places where health professionals have little knowledge or



79


experience of the disease and its control will have to be addressed (17 ). ectors

with the capacity to transmit T. cruzi have been identified since the 8th century

along maritime travel routes to parts of Africa, the Middle ast, outh-ast Asia

and the estern acific, thereby increasing the possibility of transmission in

previously non-endemic areas. xpertise in Chagas disease must be maintained.

arasitological treatment is urgently indicated for anyone in the acute phase and

for those in whom the infection has been reactivated due to immunosuppression.

n the acute cases, medicine is almost 00% effective and the disease can be

completely cured. fficacy decreases as the duration of the infection lengthens.

Additionally, during the late chronic phase, severe cardiac or digestive

manifestations may occur that require specific treatment. ide-effects are less

frequent the younger the age of the patient. arasitological treatment is also

indicated in babies with congenital infection and in patients in the early chronic

phase. n adults, especially those with the indeterminate form, parasitologicaltreatment should be offered, but the potential benefits of the treatment and its long

duration should be weighed against its frequent side-effects.

he two medicines used for treatment are benznidazole and nifurtimox. he

main contraindications to treatment are pregnancy and kidney or liver failure.

Nifurtimox is contraindicated in patients with a background of psychiatric or

neurological disorders.

here is no vaccine to prevent Chagas disease. Nevertheless, depending on the

geographical area, the following prevention and control tools are useful: vector

control (the spraying of insecticides), home improvements (such as plastering

walls, installing concrete floors and corrugated iron roofs), personal preventive

measures (such as using bednets) and good hygiene practices (when preparing,

transporting, storing and consuming food). Another preventive measure is to

screen blood donors and, before transplantation, to screen organ, tissue and cell

donors and recipients.

ey to preventing vertical transmission is the diagnosis of infected pregnant

women and the early detection of infection in neonates (secondary prevention).

he prevention of laboratory accidents requires the use of standard safety

protocols (that is, wearing laboratory coats, gloves, face masks, caps and glasses),especially when dealing with the trypomastigote form of T. cruzi (the human

infective form). Microepidemics of orally transmitted disease can be prevented

by following good manufacturing practices. n areas with malaria transmission, a

new Chagas disease surveillance system has been implemented during 2006–200.

Malaria microscopy technicians have been trained to identify T. cruzi parasites

in malaria films and, consequently, to detect acute Chagas disease in individual

cases, possible foodborne outbreaks and active transmission areas for T. cruzi.



81


REFERENCES

. ias . studos sobre o Schizotrypanum cruzi tudies of Schizotrypanum cruzi.

Memórias do Instituto Oswaldo Cruz , 934, 28():–0.

2. Wendel S. ransusion-transmit ted Chagas’ disease. Current Opinion in Hematology,

1998, 5:406–411.

3. Valente SAS, Valente VC, Fraiha Neto H. Considerations on the epidemiology and

transmission o Chagas disease in the Brazilian Amazon. Memórias do Instituto Oswaldo

Cruz , 1999, 94(Suppl. 1):S395–S398.

4. Carlier Y, orrico F. Congenital inect ion with rypanosoma cruzi: rom mechanisms o

transmission to strategies or diagnosis and control. Revista da Sociedade Brasileira de

Medicina ropical , 2003, 6:767–771.

5. Chocair PR etal. Kidney transplantation: a new way o transmitting Chagas disease,

Revista do Instituto de Medicina ropica de São Paulo, 1981, 23(6):280–282.

6. Quantitative estimation o Chagas disease in the Americas. Montevideo, Pan American

Health Organization, 2006 (OPS/HDM/CD/425-06).

7. Araujo A et al. Paleoparasitology o Chagas disease – a review. Memórias do Instituto

Oswaldo Cruz , 2009, 104(Suppl. I):S9–S16.

8. Schmunis GA. Epidemiology o Chagas disease in non endemic countries: the role o

international migration. Memórias do Instituto Oswaldo Cruz , 2007, 102(Suppl. 1):S75–

S85.

9. Chagas disease control and prevention in Europe. Report o a WHO Inormal Consultation

(jointly organized by WHO headquarters and the WHO Regional Oice or Europe).

Geneva, Switzerland, 17–18 December 2009. Geneva, World Health Organization, 2010

(WHO/HM/ND/IDM/2010.1).

10. Control o Chagas disease: second report o the WHO Expert Committee. Geneva, World

Health Organization, 2002 (WHO echnical Report Series, No. 905).

11. Rassi A, Jr, et al. Development and validation o a risk score or predicting death in Chagas’

heart disease. New England Journal o Medicine, 2006, 355:799–808.

12. Castillo-Riquelme M et al. he costs o preventing and treating Chagas disease in

Colombia. PLoS Neglected ropical Diseases, 2008, 2(11):e336.

13. Dias JC, Silveira AC, Schoield CJ. he impact o Chagas disease in Latin America: a

review. Memórias do Instituto Oswaldo Cruz , 2002, 97(5):603–612.

14. Schoield CJ, Jannin J, Salvatella R. he uture o Chagas disease control. rends in

Parasitology, 2006, 22:583–588.15. Aguilar HM et al. Chagas disease in the Amazon Region. Memórias do Instituto Oswaldo

Cruz , 2007, 102(Suppl. I):S47–S55.

16. Gürtler RE. Sustainability o vector control strategies in the Gran Chaco Region:

current challenges and possible approaches. Memórias do Instituto Oswaldo Cruz , 2009,

104Suppl. I):S52–S59.

17. Jackson Y et al. Management o Chagas disease in Europe. Experiences and challenges

in Spain, Switzerland and Italy. Bulletin de la Société de Pathologie Exotique, 2009,

102(5):326–329.



82


5.8 Human Arican trypanosomiasis

(sleeping sickness)

Abstract

Human Arican trypanosomiasis, or sleeping sickness, is one o the most

complex endemic tropical diseases. Spread by the bite o the tsetse y, the diseaseourishes in impoverished, rural parts o Arica. Sleeping sickness is one o the

ew diseases where eective treatment depends on active screening or the early

detection o cases. Symptoms in the initial phase o the illness, when treatment

has the greatest chance o success, are oen mild or nonspecifc. However, patientsrequently present or treatment when the disease is already ar advanced, when

more complex treatment is needed and when its chances o success are jeopardized.Untreated, sleeping sickness is atal. Death ollows prolonged agony.

Description

Human Arican trypanosomiasis is caused by inection with protozoan

parasites belonging to the genus Trypanosoma. It is a vector-borne disease and isusually atal i le untreated. Parasites are transmitted through the bites o tsetseies (Glossina spp.) that have acquired their inection rom humans or animals.

Following the bite o the inected y, the parasite multiplies in the lymph and

blood, causing headaches, ever, weakness and pain in the joints. Over time, the

parasite crosses the blood–brain barrier, migrates to the central nervous systemand causes severe neurological and psychiatric disorders leading to death.

he human disease takes two orms, depending on the subspecies o

trypanosome involved. rypanosoma brucei gambiense causes a chronic inectionthat may persist or months or even years without major signs or symptoms o

the disease. Trypanosoma brucei rhodesiense causes an acute inection; signs

and symptoms are observed a ew weeks aer the inective bite. Te acute orm

develops rapidly, soon invading the central nervous system.

Te secure diagnosis o human Arican trypanosomiasis requires detection o

trypanosomes in the patient. rypanosomes can be present in any body uid, butthey may be di cult to detect owing to the lack o sensitivity o parasitological

diagnostic methods and the low number o circulating parasites, especially thosebelonging to . b. gambiense (1). Serological tests are useul only or screening andestablishing suspicion o T. b. gambiense inection. In some feld circumstances,

national sleeping sickness control programmes consider a seropositive individualto be inected even in the absence o parasitological confrmation i the suspectedcase lives in highly endemic or epidemic areas.



84


Between 1999 and 2008, the reported number o new cases o the chronic ormo human Arican trypanosomiasis (T. b. gambiense) ell by 62%, rom 27 862 to

10 372 (Figure 5.8.1). Eleven countries (Benin, Burkina Faso, Gambia, Ghana,

Guinea-Bissau, Liberia, Mali, Niger, Senegal, Sierra Leone and ogo) reported no

cases, and 6 (Cameroon, Côte d’Ivoire, Equatorial Guinea, Gabon, Guinea andNigeria) reported an average o less than 100 new cases annually. Te Central

Arican Republic, Chad, Congo and Uganda each reported 100–1000 new cases

annually. Angola, the Democratic Republic o the Congo and Sudan are the mostaected countries, with each reporting an average o more than 1000 new cases

annually 5). During the same period, the number o newly reported cases o theacute orm o human Arican trypanosomiasis (. b. rhodesiense) ell by 58%, rom619 to 259 (Figure 5.8.2). Botswana, Burundi, Ethiopia, Namibia and Swaziland

reported no cases. Kenya, Mozambique, Rwanda and Zimbabwe reported sporadiccases; Malawi and Zambia reported ewer than 100 new cases each year; Uganda

and the United Republic o anzania each reported 100–1000 new cases annually (5). Te number o cases reported annually is considered to be a raction o the realnumber o inected individuals. In 2006, the total number o cases was estimatedat 50 000–70 000 6 ).

Fig. 5.8.1 Distribution o human Arican trypanosomiasis ( T. b. gambiense ), worldwide, 2008

>1 000


100–1 000

<100

0 cases reported

Endemic countries (no data available)

Non T. b. gambiense endemic countries



85


Fig. 5.8.2 Distribution o human Arican trypanosomiasis ( T. b. rhodesiense ), worldwide, 2008

≥100


<100

0 cases reported


Non T. b. rhodesiense endemic countries

40 000

1 9 9 0

Year

N u

m b e r o f n e w c a s e s r e p o r t e d

Fig. 5.8.3 Number o new cases o human Aricantrypanosomiasis reported to WHO, worldwide, 1990–2008

0

AFR EMR

35 000

30 000

25 000

20 000

15 000

10 000

5 000

1 9 9 1

1 9 9 2

1 9 9 3

1 9 9 4

1 9 9 5

1 9 9 6

1 9 9 7

1 9 9 8

1 9 9 9

2 0 0 0

2 0 0 1

2 0 0 2

2 0 0 3

2 0 0 4

2 0 0 5

2 0 0 6

2 0 0 7

2 0 0 8

AFR – Arican / EMR – Eastern Mediterranean



86


Morbidity

Te average course rom inection to death is variable but is estimated to last

six months or T. b. rhodesiense inection and three years or T. b. gambiense,

unless treatment is provided 7 ). Te disease progressively devastates the patient,mainly during the late stage. Te patient develops physical and mental disabilitiesthat have a high socioeconomic burden or impoverished amilies. Stigmatizationo patients is common. Neurological and psychiatric sequelae are requent and

permanent. In children, growth and intellectual development are impaired,

leading to learning retardation.

Rural populations, living where transmission occurs and depending on

agriculture, fshing, animal husbandry or hunting, are most oen exposed to

the bites o tsetse ies. Although both sexes have the same exposure to risk with

regard to arming, women are more likely to become inected during activities

related to maintaining the household. Overall, adult men contract more inectionsbecause they have more requent contact with vectors during hunting, fshing andother activities in the orest. Te disease can cause amenorrhoea, sterility and

abortion, and so contributes to the stigmatization o women. Children are more

likely to remain in the village and are less likely to be exposed to inection than

adults, but their risk o inection increases when they begin to accompany adultsin their activities. Additionally, some childhood activities increase their risk o

inection, such as keeping cattle, collecting water, playing in water or travelling toattend a school located outside the village. Congenital transmission o inection isrequent, and the management o inected newborns is complex.

Economic impact

Sleeping sickness, coupled with nagana, the animal orm o Arican

trypanosomiasis, has been an obstruction to the development o rural sub-

Saharan Arica and a stumbling block to increased production o livestock

and agriculture. Te FAO estimates that Arica loses US$ 1.5 billion annually

in income rom agriculture as a result o Arican trypanosomiasis (8). Human

disease reduces labour resources, and disease in animals limits the availability

o meat and milk and deprives armers o draught power. Te cases o human

Arican trypanosomiasis detected and treated during 1997–2006 averted some 10million DALYs, mostly due to the prevention o premature death 8).


Even i areas at risk are not completely covered by control and surveillance

programmes, most oci o sleeping sickness are well known. Ministries o healthcarry out interventions, through national sleeping sickness control programmes

and health systems. Case-detection and treatment are available in disease-endemic



88


endemic countries prepare control strategies, carry out interventions and monitortheir impact. Te atlas will also acilitate evidence-based estimations o at-risk

populations and the burden o disease 9).

Since 2007, in an attempt to reduce the treatment atality rate associated with

melarsoprol, eorts have been made to switch to eornithine by supplying it to

national control programmes in a standardized kit along with the appropriate

solvents and equipment. Te introduction o such a complicated protocol or

treatment was supported by ad hoc training provided by WHO. Te use o

melarsoprol has decreased rom 88% o the total second stage cases reported in

2006 to 51% in 2008 Figure 5.8.4) 10).

100

2003Year

C a s e s ( % )

Fig. 5.8.4 Treatment o second-stage cases (%) o humanArican trypanosomiasis according to medicine used,2003–2008

0

Melarsoprol Eornithine

80

60

40

20

2004 2005 2006 2007 2008

Te same approach has been introduced or the newly released combination

o eornithine and niurtimox, again made available with a kit or treatment.

Tese kits are provided by WHO along with systematic in-service training or

specialized health-care workers. WHO is playing a major part in developing

new medicines by defning the required profle o the medicine, by acilitating

clinical trials and by ensuring a distribution system is in place to provide patients

with access to new medicines. National control programmes are making eortsto obtain new diagnostics. WHO, in collaboration with partners, has set up a

specimen bank or human Arican trypanosomiasis that is available to research

institutions to acilitate the development o appropriate and aordable diagnostictools.

Te main challenge in controlling the acute orm o the disease is to control

the animal reservoir that represents the risk o permanent transmission and

unexpected epidemics. Controlling T. b. rhodesiense requires that health systems



89


be strengthened to reduce misdiagnosis and underreporting; there must also be acoordinated multisectoral approach that involves specialists in human and animalhealth, livestock, agriculture, tourism, wildlie and vector control. Although mosto the historical oci o the chronic orm o the disease are under control, the

challenge will be to sustain the progress made. Improving rural health acilitiesand ensuring access to new, sae, cheap and easy-to-use diagnostic tools and

medicine are crucial to sustaining progress made against this disease.

Assessment

Te most immediate challenge is to expand and sustain control and surveillanceactivities using the best tools available. Research into new tools should be

accelerated. Awareness about the disease should be raised, control o the disease

should be prioritized and undraising should be advocated. WHO should continueto support countries and to coordinate the work o all parties concerned with thecontrol o, and research into, human Arican trypanosomiasis.

© W

H O

Mobile team o national health

care workers perorming syste-

matic screening o population o

human Arican trypanosomiasis

(sleeping sickness) in Bodo

village, Chad.

Confrmation o inection by

serological and parasitological

tests is always ollowed by

treatment. I untreated the disea

is usually atal.



90


REFERENCES

1. Chappuis F et al. Options or the ield diagnosis o human Arican trypanosomiasis .

Clinical Microbiology Reviews, 2005, 18:133–146.

2. Control and surveillance o Arican trypanosomiasis: report o a WHO Expert Committee .

Geneva, World Health Organization, 1998 (WHO echnical Report Series, No. 881).

3. Priotto G et al. Niurtimox-elornithine combination therapy or second-stage Arican

rypanosoma brucei gambiense trypanosomiasis: a multicentre, randomised, phase III,

non-ineriority trial . Lancet , 2009, 374:56–64.

4. Courtin F et al. Sleeping sickness in West Arica (1906–2006): changes in spatial

repartition and lessons rom the past. ropical Medicine and International Health, 2008,

133:334–344.

5. Simarro PP, Jannin J, Cattand P. Eliminating human Arican trypanosomiasis: where do

we stand and what comes next? PLoS Medicine, 2008, 5:174–180.

6. Human Arican trypanosomiasis (sleeping sickness): epidemiological update. Weekly

Epidemiological Record , 2006, 81:69–80.

7. Checchi F et al. he natural progression o Gambiense sleeping sickness: what is the

evidence? PLoS Neglected ropical Diseases, 2008, 2(12):e303.8. On target against poverty: the Programme Against Arican rypanosomiasis (PAA)

1997–2007 . Rome, United Nations Food and Agriculture Organization, 2008.

9. Cecchi G et al. owards the atlas o human Arican trypanosomiasis. International Journal

o Health Geographics, 2009, 8:15.

10. Chappuis F et al. Elornithine is saer than melarsoprol or the treatment o second-stage

rypanosoma brucei gambiense human Arican trypanosomiasis. Clinical Inectious

Diseases, 2005, 41:748–751.



91


5.9 Leishmaniasis

AbstractVisceral leishmaniasis predominates in WHO’s Arican, Americas and

South-East Asia regions. Cutaneous leishmaniasis predominates in the Eastern

Mediterranean and Americas regions; and mucocutaneous leishmaniasis occursmainly in the Region o the Americas. Cases o visceral leishmaniasis that are notdetected or treated cause death within 2 years; untreated cutaneous leishmaniasismay lead to disfguring scars and stigma. Patients with mucocutaneous disease

may also be stigmatized.

Description

Leishmaniasis is a disease caused by protozoan parasites transmitted throughthe bites o inected sandies. Tis disease has a wide range o clinical symptoms.Te diering maniestations o the disease arise rom inections with dierent

species o Leishmania.

Visceral leishmaniasis, also known as kala azar, attacks the internal organs

and is the most severe orm o the disease. Le untreated, it is usually atal within2 years. Furthermore, a percentage o cases may evolve to skin dissemination

o parasites. Visceral leishmaniasis is characterized by irregular bouts o ever,

substantial weight loss, swelling o the spleen and liver, and pancytopenia. Aer

treatment, this orm may evolve into a cutaneous orm known as post-kala azar

dermal leishmaniasis, which requires lengthy treatment.

Te cutaneous orm is the most common. It usually causes ulcers on the

ace, arms and legs. Although the ulcers heal spontaneously, they cause serious

disability and leave severe and permanently disfguring scars. Te cutaneous ormmay produce up to 200 lesions and lead to disability. Te patient is le permanently scarred, and so may become socially stigmatized. Diuse cutaneous leishmaniasisproduces chronic skin lesions that never heal spontaneously. Recidivans cutaneousleishmaniasis is a relapsing orm that appears aer treatment.

Te most disfguring orm is the mucocutaneous, which invades the mucous

membranes o the upper respiratory tract, causing gross mutilation as it destroysthe so tissues o the nose, mouth and throat. Patients with this orm o the

disease may also suer rom discrimination and prejudice.

Coinection with Leishmania and HIV is an emerging problem that requires

urgent attention. Patients who are coinected, may relapse repeatedly despite

receiving proper treatment, and requently the outcome is atal 1).



92


Distribution

Leishmaniasis is a predominantly rural disease, and is prevalent in 88 countrieson 4 continents (Figure 5.9.1, Figure 5.9.2, Figure 5.9.3). Te disease is estimatedto cause 1.6 million new cases annually (2), o which an estimated 500 000 are visceral (90% o them occurring in Bangladesh, Brazil, Ethiopia, India, Nepaland Sudan) and 1.1 million cutaneous (90% o them occurring in Aghanistan,Algeria, Brazil, the Islamic Republic o Iran, Peru, Saudi Arabia, Sudan andthe Syrian Arab Republic) or mucocutaneous (90% occurring in Brazil, Peruand the Plurinational State o Bolivia). O the 1.6 million estimated cases, only about 600 000 are reported (2). Since 1993, the distribution o leishmaniasis hasexpanded, and there has been a sharp increase in the number o cases recorded (3).Since reporting is mandatory in only 33/ 88 aected countries, the true increasein cases remains unknown. Te spread o leishmaniasis is mostly caused by

voluntary and orced movement o populations that expose non-immune people

to inection (4). When leishmaniasis occurs in urban areas, conditions oenavour explosive epidemics, thereby transorming leishmaniasis rom a sporadicthreat to an epidemic threat.

Brazil has experienced a sharp increase in the number o cases o visceralleishmaniasis since 1999. Brazil has historically experienced rural epidemics in10-year cycles, but the disease now appears in urban areas as well. Te large-scalemigration o people rom rural areas to the suburbs o large cities has resulted indensely populated settlements where the newly introduced parasite encounterslarge numbers o non-immune hosts. Children are the most severely aected.Dogs are the reservoir host or the parasite in Brazil.

In Sudan, in 1997 the number o confrmed cases o visceral disease increasedour-old compared with the previous year. reatment centres were overwhelmed,and stocks o frst-line drugs were depleted. Te migration o seasonal workersand the movement o large numbers o people caused by civil unrest carried theepidemic to neighbouring countries.

Although not lethal, epidemics o cutaneous leishmaniasis are o concern inAghanistan, where war and civil unrest have avoured the spread o the diseaseand made its control di cult 5). Te disease ared up in 2002, with 40 000 casesreported in Kabul.

Te spread o HIV inection is making people more susceptible to visceral

leishmaniasis and changing the epidemiology o the disease. Te HIV pandemicin South America, Asia and Arica has expanded into remote areas, and 35/88disease-endemic countries have already reported cases o coinection o HIV and

visceral disease. In Europe, the number o new cases o visceral disease associatedwith HIV has declined since the end o the 1990s, mainly as a result o patientshaving access to antiretroviral therapy. In other parts o the world, where there isinsu cient access to antiretroviral therapy, the prevalence o visceral leishmaniasisis rising. In northern Ethiopia, the rate o coinected patients increased rom 19%during 1998–1999 to 34% during 2006–2007 1).



93


Fig. 5.9.1 Distribution o cutaneous leishmaniasis, worldwide, 2009


No cases reported

<1 000

Average numbero reported cases, 2005–2009

1 000–4 999

5 000–24 999

≥25 000

Fig. 5.9.2 Distribution o visceral leishmaniasis, worldwide, 2009


No cases reported

<1 000

Average numbero reported cases, 2005–2009

1 000–4 999

5 000–24 999

≥25 000



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Morbidity and mortality

Visceral leishmaniasis may cause large-scale tenacious epidemics with high

case-atality rates (CFRs); about 50 000 people die rom the disease annually. InEast Arica, particularly in Sudan, epidemics o visceral disease with a high CFR

are requent. Epidemics have occurred recently in Libo Kemkem, Ethiopia (2005);Wajir, Kenya (2007); and in the Upper Nile, southern Sudan (2009), among others.

Te true burden o cutaneous leishmaniasis remains largely concealed, partly

because those most aected live in remote areas with no access to treatment.

Cutaneous leishmaniasis and mucocutaneous leishmaniasis may lead to

patients being excluded rom society because many people believe that the diseaseis contagious. Mothers with cutaneous disease may rerain or be prohibited rom

touching their children; young women with scars are viewed as being unable to

marry 5); and the disease may be the pretext or a husband to abandon a wie.

Decisions about whether to seek care vary depending on the role o the patient

within the amily (whether the patient is a wage-earner, homemaker, or male

or emale child), the place o the lesion, the access to care and its aordability,

the number o amily members suering rom the disease, the perception o

treatment’s e cacy and, i the patient is a woman, whether she is pregnant.

Fig. 5.9.3 Burden o leishmaniasis, by WHO region, 2009

AFR – Arican / AMR – The Americas / EMR – Eastern Mediterranean / EUR – European / SEAR – South-East Asia / WPR – Western Pacifc

AFR17 %

SEAR66 %

WPR1%

AMR3%EMR12%

EUR1%



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Te sex ratio diers by ecological and cultural setting. Because o occupationalexposure to sand lies, there are settings in which men are more aected

than women. In other cases, the burden o the disease among women may

be underestimated because women have limited access to health acilities.


For more than 70 years, the frst-line treatment in most countries has been

injectable pentavalent antimonials. Te treatment is lengthy, potentially toxic,

and painul; it has become ineective in parts o India and Nepal as resistance hasdeveloped (6 ). In the case o relapse, patients need treatment with a more toxic,

second-line medicine, such as amphotericin B or pentamidine. Newly developed,

liposomal amphotericin B is highly eective, has almost no side-eects and is

now the preerred frst-line treatment or visceral disease (7 ). Tis medicine is tooexpensive to be widely used by developing countries. Other eective medicines

are milteosine 8) and paromomycin 9).

Improved control o leishmaniasis will have a major benefcial impact on

mortality and morbidity. Where the inection aects only humans, transmission

can be reduced by implementing a combination o active case-detection and early treatment. Knowledge o this possibility led to the signing o a memorandum

o understanding in 2005 by Bangladesh, India and Nepal to eliminate visceral

leishmaniasis by reducing the incidence o the disease to less than 1 case/10 000

individuals by 2015 10).

Tere is a need to strengthen active case-detection o both cutaneous and

visceral disease, and to strengthen the ability to diagnose these at peripheral

health centres where patients are usually treated based only on clinical symptoms.

A consensus has emerged that anthroponotic visceral leishmaniasis – which hasthe potential to develop drug resistance – should be treated with a combination

o medicine instead o with monotherapy. rials o promising combinations o

medicine are under way, and it is expected that combination treatment will preventresistance rom developing and shorten the duration o treatment, which, in turn,

will make it more likely that patients complete treatment. Combination therapy

also will reduce side-eects, be cheaper and allow programmes to be more cost-

eective. In 2009, it was recommended that liposomal amphotericin B should be

used as an interim strategy until combinations can be implemented. In 2010, this

medicine was ound to be eective in India in a single-dose regimen; this oers

new perspectives or control programmes working in the Indian subcontinent (11).



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5.10 Cysticercosis

Abstract

Human cysticercosis is caused by the development o Taenia solium cysticerci

in human tissues. Cysticerci that develop in the central nervous system causeneurocysticercosis. Neurocysticercosis is considered to be a common inection o the human nervous system. Neurocysticercosis is the most requent preventable

cause o epilepsy in the developing world. More than 80% o the world’s 50 millionpeople who are aected by epilepsy live in developing countries, many o which

are endemic or T. solium inections in people and pigs.

Description

Humans acquire cysticerci by ingesting the tapeworm’s eggs. Cysticerci

also develop in the muscles o pigs that have swallowed T. solium eggs. Teconsumption o undercooked pork by humans completes the tapeworm’s lie-

cycle. Te requency o the disease has decreased in developed countries owing

to stricter meat-inspection standards, improved hygiene and better sanitary

acilities. Preventing the disease requires strict meat inspection regimens, healtheducation, thorough cooking o pork, sound hygiene, and adequate water and

sanitation.

Symptoms include epileptiorm attacks, headaches, learning diiculties

and convulsions. Te location o inection that most oen prompts a medical

consultation is the central nervous system, ollowed by the eye and its surrounding

tissues. reating cysticercosis is di cult, and not always successul.Cysticercosis mainly aects the health and livelihoods o subsistence armers in

developing countries o Arica, Asia and Latin America Figure 5.10.1). Althoughtheoretically amenable to control and declared eradicable by the International

ask Force or Disease Eradication in 1993, cysticercosis remains a neglected

disease given the lack o inormation about its burden and transmission, the lack o diagnostic tools available or use in the feld, and the lack o validation o simpleintervention packages used as part o integrated helminth control strategies.



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Distribution

Cysticercosis has been a serious problem in atin America for decades.

otspots of the disease include the Bolivarian epublic of enezuela, northern

Brazil, Colombia, cuador, uatemala, onduras, Mexico, Nicaragua, eru

and the lurinational tate of Bolivia. he disease is also endemic in aiti and

possibly the ominican epublic. tudies in Brazil and the nited tates indicate

that neurocysticercosis is an important cause of human deaths (1, 2). n spite of

the importance of cysticercosis in ’s egion of the Americas, surveillance

or control programmes have been only rarely established.Cysticercosis has emerged as a public-health and agricultural problem in most

of sub-aharan Africa, from Cape erde to Madagascar, because of the increasing

popularity of raising pigs and consuming pork. xceptions in ’s African

egion include the mainly Muslim countries of Algeria, the Comoros, Mauritania

and Niger, as well as in countries with low pork consumption, such as Botswana,

the Congo, abon and amibia. Community-based surveys of human and porcine

cysticercosis have been undertaken in the following countries where the disease

Fig. 5.10.1 Countries and areas at risk o cysticercosis, 2009

Endemic (ull lie-cycle)

Suspected endemic

Imported cases (possible human cysticercosis transmission)

No data available



99


is believed to be prevalent, though mainly with focal distribution: Benin, Burkina

aso, Burundi, Cameroon, the Central African epublic, Chad, Côte d’voire, the

emocratic epublic of the Congo, hana, enya, Madagascar, Mozambique,

Nigeria, wanda, enegal, outh Africa, ogo, ganda, the nited epublic of

anzania, ambia and imbabwe (3–6 ). Cysticercosis has received little attentionfrom national and regional authorities. he results of recent studies (7, 8) have

linked the high prevalence of epilepsy with neurocysticercosis.

he disease is endemic in Bhutan, ndia, parts of ndonesia (Bali and apua),

Nepal and imor-este; the situation is unknown in Bangladesh, the emocratic

eople’s epublic of orea and ri anka. Case reports suggest that the disease

is endemic in Myanmar and hailand; a recent survey indicated taeniasis

solium (presence of adult T. solium in human intestine) is common in western

hailand. Cysticercosis occurs in all states in ndia, although the predominantly

Muslim states of ammu and ashmir and the affluent state of erala report

few cases. Neurocysticercosis is the cause of epilepsy in up to 50% of ndian

patients presenting with partial seizures; ocular cysticercosis is also common.

More than half of patients suffering seizures caused by neurocysticercosis are

diagnosed with a solitary cysticercus granuloma. nterestingly, a large proportion

of ndian patients diagnosed with neurocysticercosis is vegetarian or does not

report consuming pork (9). urveys conducted in 008 in ndonesia suggest that

the incidence of cysticercosis has decreased in Bali; apua is considered to have

one of the highest levels of endemicity in ndonesia.

Cysticercosis has been reported in 29 administrative divisions of China, and in

004 was included for the first time in the national survey of parasitic diseases.Cysticercosis appears to be highly endemic in the south-west provinces of

ichuan, unnan and uizhou. n mainland China, the results of a meta-analysis

of data, from the 930s to the 000s, showed that human cases of taeniasis and

cysticercosis were found in all 3 provinces, municipalities and autonomous

regions in mainland China, and there were 5 epidemic zones. he average

incidence of T. solium infection in China was 0.% (range, 0.046–5%); the

estimated number of taeniasis solium patients was .26 million; and the estimated

number of cysticercosis cases was 3–6 million. he incidence of cysticercosis

varied from 0.4% to 3.% in endemic areas. he majority of cases occurred

among people aged 0–50 years, who accounted for 3% of all cases. he ratioof male cases to female cases was .4:. About 00 000 tonnes of infected pork

are discarded annually in China, causing a loss of billion renminbi (about

46 million) (10).

Community-based surveys of cysticercosis in iet Nam have detected foci

in villages in the northern part of the country where traditional dishes using

raw pork are popular. ost-mortem surveys of pigs indicate that the infection

is present in the southern part of iet Nam. here are no published reports



100


from community-based surveys on cysticercosis in Cambodia, the ao eople’s

emocratic epublic, Malaysia or the hilippines, but case reports suggest that

cysticercosis is probably endemic in those countries.

iven the absence of pig-keeping and pork consumption in the asternMediterranean egion, T. solium cysticercosis is not considered to be a problem

there except in non-Muslim communities in gypt and southern udan. here are

reports of human cysticercosis occurring in more affluent countries in the region;

these have been linked to transmission through workers from countries where the

disease is endemic.

Morbidity

Morbidity mostly occurs when the cysticerci develop in the brain causing

neurocysticercosis. Te incubation period is variable, and inected people may remain asymptomatic or years. Te cysticerci may evade the host’s immune

system so that viable cysts with little or no inammatory reaction are usually

not associated with symptoms. When cysts are recognized by the host ollowing

spontaneous degeneration or aer treatment, an inammatory reaction may

occur; this usually results in clinical symptoms, including chronic headaches,

blindness, seizures (epilepsy i they are recurrent), hydrocephalus, meningitis,

symptoms caused by lesions occupying spaces o the central nervous system,

dementia and even death. In severe cases, neurocysticercosis may be atal and

it has been noted as a cause o death among young adult Hispanics and Latinos

in the United States. Oedema around calcifed cysticercal granulomas also has

been ound to cause symptoms. Te requency o sequelae ollowing inection

with cysticerci remains unknown. Te duration o symptoms associated with

neurocysticercosis, and the proportion o patients that will ully recover with or

without treatment, are ill-defned. Neurocysticercosis is now considered to be a

common helminth inection o the human nervous system and the most requentpreventable cause o epilepsy in the developing world. Te disease aects rom

20% to 50% o late-onset epilepsy cases globally, and is reported to be a common

cause o juvenile epilepsy in certain countries, such as India and South Arica.

Tere are about 35 000 cases o epilepsy associated with neurocysticercosis inthe Eastern Cape province o South Arica, and more than 400 000 symptomatic

cases in Latin America. Te occurrence o the disease in developing countries is

expected to increase as the demand or pork grows in countries where T. solium

is endemic. WHO estimates that at least 50 million people suer rom epilepsy,

more than 80% o whom live in developing countries. Approximately one third o all cases o epilepsy occur in regions where endemic T. solium is associated with

neurocysticercosis.



102


In 2009, all aspects o controlling . solium inections and disease were discussedduring an expert consultation on oodborne trematodiasis and taeniasis and

cysticercosis held in Vientiane, Lao People’s Democratic Republic. Te meeting

issued guidance that ocused on using improved preventive chemotherapy in

humans and pigs, and the vaccination o pigs. Tese tools should be ready or usein the feld within 2–3 years. Te group urther acknowledged that community-ledtotal sanitation that is, the provision o adequate water and sanitation organizedby the community itsel) is a novel approach to behavioural change and has the

potential to be scaled up with minimal investment 13).

Assessment

Te elimination o cysticercosis requires improvements in chemotherapy or

humans and pigs, and the vaccination o pigs. Neurocysticercosis is the most

requent and preventable cause o acquired epilepsy in developing countries.

REFERENCES

1. Flisser A. Epidemiological studies o taeniosis and cysticercosis in Latin America. In:Craig P, Pawlowski Z, eds. Cestode zoonoses: echinococcosis and cysticercosis. An emergent

and global problem. Amsterdam, IOS Press, 2002:3–11 (NAO Science Series. Series I: Lie

and Behavioural Sciences, Vol. 341).2. Sorvil lo FJ, DeGiorgio C, Waterman SH. Deaths rom cysticercosis, United States.

Emerging Inectious Diseases, 2007, 13:230–235.3. Andriantsimahavandy A et al. Situation épidémiologique actuelle de la cysticercose à

Madagascar [Epidemiological situation o cysticercosis in Madagascar]. Archives de

l’Institut Pasteur de Madagascar , 2003, 69(1-2):46–51.4. Maojane NA et al. he current status o neurocysticercosis in Eastern and Southern

Arica. Acta ropica, 2003, 87:25–33.5. Geerts S et al. he taeniasis-cysticercosis complex in West and Central Arica. Southeast

Asian Journal o ropical Medicine and Public Health, 2004, 35(Suppl.1):S262–S265.6. Murrell KD. Epidemiology o taeniosis and cysticercosis. In: Murrell KD, ed. WHO/FAO/

OIE guidelines or the surveillance, prevention and control o taeniosis/cysticercosis. Paris,OIE, WHO, FAO, 2005:27–43.

7. DeGiorgio CM et al. Neurocysticercosis. Epilepsy Currents, 2004, 4(3):107–111.8. Winkler AS et al. Epilepsy and neurocysticercosis in sub-Saharan Arica. Wiener Klinische

Wochenschrit , 2009, 121(Suppl. 3):S3–S12.9. Rajshekhar V et al. aenia solium taeniosis/cysticercosis in Asia : epidemiology, impact

and issues. Acta ropica, 2003, 87(1):53–60.10. Chen Y, Xu L, Zhou X. Distribution and disease burden o cysticercosis in China. Southeast

Asian Journal o ropical Medicine and Public Health, 2004, 35(Suppl. 1):S231–S239.11. Carabin H et al. Estimation o the cost o aenia solium cysticercosis in Eastern Cape

Province, South Arica. ropical Medicine and International Health, 2006, 11:906–916.12. Praet N et al. he disease burden o aenia solium cysticercosis in Cameroon. PLoS

Neglected ropical Diseases, 2009, 3(3):e406.13. Report o the WHO Expert Consultation on Food-Borne rematode Inections and

aeniasis/Cysticercosis. Vientiane, Lao People’s Democratic Republic, 12–16 October 2009.

Geneva, World Health Organization, 2010.

© W

H O

Farmer transporting a pig in rural Cambodia.

Cysticercosis has a serious impact on the agricultural

systems o pig-producing communities. Cysticercosis is

responsible or poor pork quality and the labelling o pig

carcasses as condemned, thereby reducing armers’ income.



106


REFERENCES

1. Dracunculiasis – global surveillance summary, 1994. Weekly


2. Dracunculiasis – global surveillance summary, 1992. Weekly


3. Monthly report on dracunculiasis cases, January–April 2009. Weekly

Epidemiological Record , 2009, 84:203.

4. Monthly report on dracunculiasis cases, January–May 2009. Weekly


5. Monthly report on dracunculiasis cases, January–July 2009. Weekly


6. Monthly report on dracuncul iasis cases, January–August 2009.

Weekly Epidemiological Record , 2009, 84:466–467.

7. Dracunculi asis eradication-global surveill ance summary, 2009.

Weekly Epidemiological Record , 2010, 85:165–176.

8. Jim A, andon A, Ruiz-iben E. Cost-beneit analysis o the global

dracunculiasis eradication campaign. Washington DC, World Bank,

1997 (Policy Research Working Paper No. 1835).

9. Certiication o dracunculiasis eradication: criteria, strategies,

procedures. Geneva, World Health Organization, 1996.

Fig. 5.11.2 Status o dracunculiasis eradication, worldwide, 2010

Countries currently endemic or dracunculiasis

Countries in the precertifcation stage

Previously endemic countries certifed ree o dracunculiasis

Other countries and territories certifed ree o dracunculiasis

Countries and territories not known to have dracunculiasis but yet to be certifed

© W

H O

Filtering drinking-

water using a fne

mesh in N iger.

Dracunculiasis

(guinea-worm

disease) aects

people in rural,

deprived and

isolated communities

who have no sae

drinking water supply

and who depend

mainly on open water

sources, such as ponds.



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5.12 Echinococcosis

Abstract

Cystic echinococcosis (hydatid disease) and alveolar echinococcosis develop

when humans ingest eggs o Echinococcus granulosus or E. multilocularis,

respectively, which are shed in the aeces o dogs harbouring adult stages o

these tapeworms. Echinococcosis has a global distribution, and causes serious

morbidity and death i untreated.

Description

Cystic echinococcosis is principally maintained in a dog–sheep–dog cycle. Teinection is transmitted to dogs when they are ed inected viscera o sheep or other

ruminants during the home-slaughter o animals. Dogs also become inectedthrough scavenging. Direct contact with dogs and consuming vegetables and

water contaminated with inected dog aeces are important modes o transmissionto humans. Humans are accidental intermediate hosts and are not able to transmitthe disease. Tere are areas o high endemicity in southern South America, the

Mediterranean coast, the southern part o the ormer Soviet Union, the Middle

East, south-western Asia, northern Arica, Australia, Kenya, New Zealand and

Uganda 1).

Human cystic echinococcosis (or hydatidosis) is a disease caused by the larvalstages o the dog tapeworm E. granulosus Cestoda). In its domestic transmission

cycle, dogs are defnitive hosts o the adult tapeworm, and ruminants (particularly sheep and goats) are intermediate hosts. Humans become accidental intermediatehosts ollowing ingestion o eggs through direct contact with defnitive hosts or

indirectly through ood, water or soil contaminated with eggs. Te larval stage

that emerges rom the egg gives rise to a hydatid cyst. A cyst slowly enlarges,

and signs and symptoms o disease vary according to its location and size in

the body, duration o the development o the cyst, and the cyst type, which is

defned according to the classifcation system o WHO’s Inormal Working Groupon Echinococcosis. Cases o inection with more than one cyst occur. Cysts are

ound mostly in the liver and lungs, although other organs may be aected. Cysticechinococcosis, a chronic disease with an asymptomatic period o several years,

is di cult to diagnose without imaging tools (such as computed tomography or

ultrasound); laboratory confrmation o the disease relies on good serological tests.reatment comprises mainly surgical intervention or percutaneous treatment

and/or high dose, long-term therapy with albendazole alone or in combination

with praziquantel (2). Surveillance in animals is di cult because the inection

is asymptomatic in livestock and dogs, and is not recognized or prioritized by

communities or local veterinary services.



108


Distribution

Echinococcosis is widely distributed Figure. 5.12.1). Prevalence and incidencedata in animals and humans are variable and, even when the disease is notifable,

its occurrence is requently underreported (3). Given the unreliability o data onhuman cystic echinococcosis, the fgures by country or the collated numbers o

cases are estimates based on prevalence o abdominal cysts detected by ultrasoundin at-risk rural populations or extrapolated rom hospital data mostly collected

during special surveys. Data indicate that Echinococcus inection is re-emerging

as an important public-health issue 4).

Human cystic echinococcosis is endemic in parts o east Arica. Te disease

is present in domestic and wild ungulate populations, and in canids in west and

central Arica. Te disease is more prevalent in the Nilotic pastoral populations.

Between 1981 and 2002, a total o 663 cases average age 27 years) were operated

on in northern urkana in Kenya (5). In that region in 2002, the prevalence in dogswas 33% and in livestock 3–60%. O 234 cases surgically treated in Addis Ababa,Ethiopia, 94 cases (40%) occurred in Oromiya state. Echinococcus granulosus is

present in livestock in Somalia but appears not to be a human problem. In 2008,Echinococcus isolates rom lions in Uganda were shown by DNA analysis to be a

separate species E. elidis), the zoonotic potential o which is unknown. Humancases o cystic echinococcosis have occurred in Angola but no data are available.

Echinococcus granulosus is transmitted between dogs and livestock in the majorpastoral areas o South America. Human cystic echinococcosis cases occur in

Argentina (especially Patagonia), south Brazil (Rio Grande do Sul), Chile, Peru

(mainly in the Andes), the Plurinational State o Bolivia (Andes) and Uruguay.Te sheep–dog strain G1 genotype) predominates, while inections with G5, G6and/or G7 pig strain) have occurred in Argentina and Chile; inections with G5(cattle strain) have occurred in south Brazil. Long-term control programmes havebeen implemented with variable success in south Chile (1979–1997), Uruguay

(1965–current) and south-central Argentina (1970–current), although new humancases continue to occur in several regions. In Patagonia, the annual incidence,

calculated as the number o surgeries or the disease, was more than 200/100 000population in Neuquen and Chubut. In Peru, the incidence among humans by

administrative department in 2005 ranged rom 0 to more than 30/100 000, witha mean o 9/100 000 annually; and the incidence o abdominal ultrasound was

4.7% in highland communities (6 ). Community ultrasound surveys revealed

prevalences ranging rom 3% to 9% in Andean populations, indicating a signifcanthealth burden. Cystic echinococcosis in Brazil is a public-health and economic

problem in the southern state o Rio Grande do Sol; the prevalence is 30% in

sheep and 11–38% in dogs. Echinococcus granulosus occurs rarely in Mexico andGuatemala but is sustained in pig–dog cycles. Tere are no indications o cystic

echinococcosis transmission in Haiti. In central and south America, two other

species o tapeworm (E. vogeli and E. oligarthrus) occur in wildlie cycles and both



109


have zoonotic potential. Echinococcus vogeli is more important because domesticdogs become inected by eating rodents (agouti, paca), thereby causing human

polycystic echinococcosis (about 150 cases have been described mainly in the

Amazonas regions o Brazil and Colombia).

Cystic echinococcosis is endemic throughout WHO’s Eastern Mediterranean

Region, but data on the disease in humans is ragmented, except in the

Islamic Republic o Iran. Cystic echinococcosis is endemic in people and

animals throughout the country, while more than 100 cases o human alveolar

echinococcosis have occurred in the north-west zone bordering Azerbaijan

and urkey. Te prevalence o cystic echinococcosis in humans as detected by

ultrasound ranges rom less than 0.5% to 1.5%; 1227 cases were surgically treatedin three hospitals in Shiraz between 1978 and 1998. Human seropositivity was

greater than 5% in the west and south-west o the Islamic Republic o Iran, with

2–18% seroprevalence in nomadic groups (7 ): hydatid control programmes

have not been implemented in the country. Cystic echinococcosis is not a majorpublic-health problem in Egypt, but inections in livestock are not uncommon.

Te incidence o surgery among humans varied rom 0.8 to 2.6/100 000, with

most cases occurring in Matrouh and Giza governorates. In Sudan, human cysticechinococcosis is mainly a health problem or pastoral tribes in the ar south

where the ultrasound prevalence in oposaland during the late 1990s ranged rom0.5% to 3.5%. Human cases have been recorded in Aghanistan, Pakistan and

Yemen, but ew data have been collected.

Human cystic echinococcosis is endemic throughout southern Europe, Near

East, Central Asia and much o central and eastern Russia. Cystic echinococcosis

is a public-health problem in urkey, with an average incidence in humans o 4.7/100 000 annually range 0.87–20/100 000); 21 303 cases were treated between1987 and 1994.

Human alveolar echinococcosis is endemic in eastern urkey mainly in Karsand Erzurum provinces) with 207 cases recorded up until 1995 8). Human cysticechinococcosis and a ew alveolar echinococcosis cases have been reported in

Azerbaijan; 484 cases o cystic echinococcosis had been treated surgically over 15years in Baku up until 2008. Human cystic echinococcosis persists in Albania, theRussian Federation, ajikistan and Uzbekistan. Alveolar echinococcosis is also

present in Kyrgyzstan, the Russian Federation, Siberia, ajikistan and Uzbekistan.

Cystic echinococcosis is endemic in Bangladesh, Bhutan, India and Nepal, andcauses disease in livestock and people. Te inection and the disease are assumedto be o low endemicity or absent rom Cambodia, Indonesia and the Lao People’sDemocratic Republic since there is little or no inormation on echinococcosis in

that area. Both cystic echinococcosis and alveolar echinococcosis are endemicin China, with cystic echinococcosis reported in 20/32 provinces or autonomousregions. Eight provinces and autonomous regions o China account or most caseso both cystic echinococcosis and alveolar echinococcosis, with greatest disease



111


MorbidityMortality rom cystic echinococcosis ranges between 2% and 4% but it may

increase considerably i medical treatment and care are inadequate. Cystic

echinococcosis is a health problem or children in endemic regions, and reports

o paediatric cases are increasing in some areas. Te disease in children is anindicator o the “parasite pressure” in the area, revealing ongoing transmissiono inection. In children the disease diers in several aspects rom that in adults.Cysts are more requent in males and the liver and lungs are equally aected.Cysts in children enlarge more rapidly than in adults and cause symptoms earlier,resulting in earlier detection. Te so-called rare locations are more commonly detected in children. Tese include the central nervous system, pelvis, peritonealcavity, diaphragm, so tissues, abdominal wall, head and neck region, heart,kidney, spleen, orbit, bone and spine; 50–75% o cases o central nervous system

involvement in cystic echinococcosis are reported in children 11).

he global burden o cystic echinococcosis has been estimated to beapproximately 1 million DALYs (range 860 000–1 175 000), assuming an

underreporting o cases. Further estimates indicate that approximately 200 000new cases are diagnosed annually. Te fnancial burden o the disease in estimateso purchasing power parity is approximately US$ 4.1 billion annually, o which46% is associated with human treatment and morbidity and 54% with animal-health costs. Te burden o human disease o 1 million DALYs is greater than thato several other conditions in the cluster o NDs, such as dengue, Chagas diseaseand onchocerciasis, but less than that o trypanosomiasis and schistosomiasis (12).Although most cases are associated with direct contact or close association with

dogs, an unknown proportion o cases may be associated with contamination o human ood and water with canine aecal material.

Prevention and controlControl programmes directed at the regular deworming o dogs combined with

public inormation campaigns and improved post-mortem examinations, thecondemning o oal and proper destruction at the slaughterhouse, may eventually be eective. Tese measures will require at least 5 years and possibly more than10 years to achieve results, and are expensive and di cult to sustain 13). Tere isno vaccine or dogs, although research is under way 14). An eective vaccine or

ovine echinococcosis has been developed (15) and may become available soon.Community ultrasound surveys have been used to raise awareness in communitiesconsidered to be at risk 16 ).

AssessmentControl interventions based on regularly deworming dogs, providing health

inormation and inspecting meat have the potential to reduce the impact

o echinococcosis but will take some years to achieve results and will require

considerable resources.



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REFERENCES

1. Parasitoses. In: Hydatidosis in zoonoses and communicable diseases common to man and

animals, 3rd ed. Washington, DC, Pan American Health Organization, 2003, Volume

III:184–199.

2. Brunetti E et al. Expert consensus or the diagnosis and treatment o cystic and alveolar

echinococcosis in humans. Acta ropica, 2010, 114(1):1–16.3. Eckert J et al, eds. WHO/OIE manual on echinococcosis in humans and animals: a

public health problem o global concern . Geneva, World Health Organization and World

Organisation or Animal Health, 2001.

4. Jenkins D, Romig , hompson R. Emergence/re-emergence o Echinocccus spp. A global

update. International Journal or Parasitology, 2005, 35:1205–1219.

5. Cooney RM, Flanagan KP, Zehyle E. Review o surgical management o cystic hydatid

disease in a resource limited setting: urkana, Kenya. European Journal o Gastroenterology

and Hepatology, 2004, 16:1233–1336.

6. Gavidia CM et al. Diagnosis o cystic echinococcosis, central Peruvian highlands.

Emerging Inectious Diseases, 2008, 14:260–266.

7. Sarkari B et al. Human cystic echinococcosis in Yasuj District in Southwest o Iran:

an epidemiological study o seroprevalence and surgical cases over a ten-year period.

Zoonoses and Public Health, 2008, 57(2):146–150.

8. Altintas N. Cystic and alveolar echinococcosis in urkey. Annals o ropical Medicine and

Parasitology, 1998, 92:637–642.

9. ity et al. chinococcosis in ibetan populations , western ichuan province, China.

Emerging Infectious Diseases , 2005, :866–83.

0. eskin et al. ydatid cysts in children article in rench. Journal de Chirurgie (Paris),

99, 28():42–44.

11. orgerson PR et al. he global burden o alveolar echinococcosis. PLoS Neglected ropical

Diseases, 2010, 4:e722.

12. Budke C, orgerson P, Deplazes P. Global socioeconomic impact o cystic echinococcosis.

Emerging Inectious Diseases, 2006, 12(2):296–303.

13. Craig PS, Larrieu E. Control o cystic echinococcosis/hydatidosis: 1863–2002. Advances

in Parasitology, 2006, 61:443–508.

14. Petavy A et al. An oral recombinant vaccine in dog against Echinococcus granulosus, the

causative agent o human hydatid disease: a pilot study. PLoS Neglected ropical Diseases,

2008, 2(1):e125.

15. Lightowlers M et al. Vaccination against cysticercosis and hydatid disease. Parasitology

oday, 2000, 16:191–196.

16. Kachani M et al. Public health education: importance and experience rom the ield.

Educational impact o ultrasound screening surveys. Acta ropica, 2003, 85:263–269.

© W

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The human-animal interace in a street market

scene in Mbou r, Senegal.

As many diseases aecting vulnerable populations

originate rom animals, an integrated human and

animal health approach is needed to prevent

disease occurrence in humans.



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Foodborne trematode inections have been neglected by the international

community. he absence o conclusive inormation on their geographical

distribution and burden means that their public-health impact may have been

underestimated or decades. Only a small proportion o those who are inected

receive adequate treatment; others are orced to conront chronic disease and,in the most severe cases, death. In 1995, a WHO Study Group estimated that

at least 40 million people were inected (1). Considering the usual resistance to

modiying ood habits, which are deeply rooted in the culture and traditions o

aected populations, and the act that these diseases mainly aect marginalized

communities not beneiting rom social and economic development, it is

reasonable to assume that the number o inected individuals is increasing as a

consequence o population growth in endemic countries.

Morbidity

Foodborne trematode inections are characterized by a chronic clinicalevolution reecting the steady accumulation o adult worms in the body throughsubsequent rounds o inection. Early and light inections are usually asymptomaticor only responsible or mild symptoms, such as ever, loss o appetite and atigue.Fascioliasis is a notable exception and is characterized by a critical acute phase

marked by severe abdominal pain, corresponding to the migration o the large

parasites through the liver tissues.

As the number o worms increases so does long-standing inammation o

the biological tissues harbouring them. In chronic ascioliasis, inammation

o the larger bile ducts where the adult worms lodge may lead to fbrosis o thesurrounding liver tissue and eventually to cirrhosis, ascites and impairment o liverunction; anaemia is also a typical fnding. In clonorchiasis and opisthorchiasis,

the adult worms lodge in the intrahepatic bile ducts; chronic inammation o

the ducts may result in cholangiocarcinoma, a severe malignancy that almost

invariably leads to death i not adequately addressed. Te clinical picture o

paragonimiasis resembles that o pulmonary tuberculosis: chronic inammationo the lungs associated with severe chest pain, chronic dyspnoea, respiratory

ailure and expectoration o blood ollowing paroxysmal coughing. Among

ectopic cases, cerebral casese are the most severe and may be associated with

epilepsy, neurological impairment and dementia.Dierences in age and sex in the epidemiology o oodborne trematode

inections are mainly related to ood habits. In rural communities in the Republico Korea, raw fsh dishes are typically enjoyed over alcohol: such practices excludechildren and are more common among males than emales; the epidemiology

o clonorchiasis and opisthorchiasis relects this demographic pattern. In

mountainous areas o northern Viet Nam, where catching and eating crabs aersummarily roasting them is a common practice among children, severe cases o



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paragonimiasis may already be encountered in adolescents and young adults. In

Egypt, ascioliasis mainly aects girls and young women employed in agriculturalwork in irrigated plantations where they consume raw vegetables.

Economic aspectsFood saety standards are rarely applied to the small amily businesses and

inormal home fsheries that currently represent an important source o inectionor clonorchiasis and opisthorchiasis (2). On the other hand, industrial aquacultureis expanding in developing countries as a way to maintain ood security, and theimpact on loss o production generated by the associated introduction o ood

standards is likely to be signifcant. Te case o ascioliasis appears similar since

the aquaculture o plants is an increasing source o inection. In addition, given

that the main reservoir hosts are livestock (cows, bualoes, sheep), the impact

o ascioliasis on livestock breeding is signifcant. In the case o paragonimiasis,

although most inections occur in remote rural areas and are associated withconsumption o wild crabs, the health risk and the consequent economic loss

associated with an expansion o aquaculture should not be underestimated.

Prevention and controlPreventive chemotherapy against clonorchiasis and opisthorchiasis has been

implemented in the most aected countries, but the scale is limited and not all

individuals who need treatment are reached (3). Donated triclabendazole is helpingto expand control o human ascioliasis 4). Te donation has allowed preventivechemotherapy to be delivered to the most-aected areas and has improved accessto individual case-management in less endemic settings. Paragonimiasis remainslargely unaddressed, and the scale o treatment activities is limited.

Praziquantel is active against the more common oodborne trematode

inections: clonorchiasis, opisthorchiasis and paragonimiasis. riclabendazole is

used to treat ascioliasis and paragonimiasis.

he lack o knowledge about the distribution o these diseases, the

underreporting o cases and poor awareness o the public-health signifcance o

oodborne trematode inections have limited the expansion o control activities.

In some settings, patients are exclusively dealt with through a case-managementapproach. No mechanisms or case-detection are in place, and only those

individuals who spontaneously present to health centres are treated – that is, thosesuering rom advanced stages o disease. Access to treatment is limited becausemedicines are not available or are unaordable or those inected.

AssessmentPreventive chemotherapy using praziquantel and triclabendazole has been

introduced on a limited scale to control the our most common orms o oodbornetrematode inections. Te use o preventive chemotherapy should be scaled up asshould eorts to increase health awareness and improve ood hygiene.



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REFERENCES

1. Control o oodborne trematode inections. Report o a WHO Study Group. Geneva, World

Health Organization, 1995 (WHO echnical Report Series, No. 849).

2. Report o the joint WHO/FAO workshop on oodborne trematode inections in Asia. Ha Noi,

Viet Nam, 26–28 November 2002. Manila, World Health Organization Regional Oice or

the Western Paciic, 2004.

3. Report o the WHO Expert Consultation on Food-Borne rematode Inections and

aeniasis/Cysticercosis. Vientiane, Lao People’s Democratic Republic, 12–16 October 2009.

Geneva, World Health Organization, 2010.

4. Report o the WHO Inormal Meeting on use o triclabendazole in ascioliasis control.

WHO headquarters, Geneva, Switzerland, 17–18 October 2006 . Geneva, World Health

Organization, 2007.

© W

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Man cleaning fsh in Thanh Hóa p rovince, north central

Viet Nam. Consumption o traditional dishes containing

raw resh-water fsh is linked with transmission o

clonorchiasis and opisthorchiasis.



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5.14 Lymphatic f lariasis

AbstractLymphatic flariasis arises rom inection with mosquito-borne flarial worms.

Te Global Programme to Eliminate Lymphatic Filariasis, launched by WHO

in 2000, has delivered 2.45 billion treatments to people in need to interrupt

transmission and control morbidity.

Description

Lymphatic flariasis, which is mostly acquired in childhood, remains silent ora long time aer inection. Mosquitoes that bite inected humans transmit the

disease. Te thread-like, parasitic flarial worms Wuchereria bancrofi, Brugiamalayi and Brugia timori that cause lymphatic flariasis live almost exclusively

in humans. Tese worms lodge in the lymphatic system, the network o nodes

and vessels that maintain the delicate uid balance between the tissues and

blood and are an essential component o the body’s immune deence system. Teworst symptoms o chronic disease generally appear in adults and in men more

oen than in women: these are damage to the lymphatic system, kidneys, arms,

legs or genitals (especially in men) that causes signifcant pain, large-scale lost

productivity and discrimination.

DistributionProgress has been made in mapping the distribution o lymphatic flariasis

during the past decade. Altogether 79/81 endemic countries have initiated

mapping the distribution o the disease. Globally, 1334 million people live in the81 countries where the disease is known to be endemic (Figure. 5.14.1). Prior to

Global Programme to Eliminate Lymphatic Filariasis, there were an estimated

115 million people inected with W. bancrofi and 13 million with Brugia spp 1).WHO’s Arican and South-East Asia regions harbour 95% o the population livingin endemic areas, and 98% o the inected population. O the endemic population,874 million (65%) live in the South-East Asia Region (9 endemic countries) and

396 million (30%) live in the Arican Region (39 countries). Te Mekong Plusarea (6 countries) accounts or 3%; and the Region o the Americas, Eastern

Mediterranean Region and Oceania (with 7, 3 and 17 countries, respectively)

together account or 2% (Figure 5.14.2) (2). All Brugia inections are confned to

countries o the South-East Asia Region. en previously endemic countries have

not reported oci and are ree rom the disease (Burundi, Cape Verde, Rwanda,

Mauritius and the Seychelles in the Arican Region; Costa Rica, Suriname and

rinidad and obago in the Region o the Americas; and Brunei Darussalam and



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the Solomon islands in the Western Pacifc Region). Consultations are being heldby the international community to develop a mechanism to veriy claims that

countries are ree o the disease.

All countries o the major endemic region – the South-East Asia Region –

have initiated mass drug administration, although geographical coverage needs

to be extended in Bangladesh, Indonesia, Myanmar, and imor-Leste. O the

39 endemic countries in the Arican Region, 17 have yet to start mass drug

administration, and some countries have only l imited geographical coverage.

Te limited progress made in some countries o the South-East Asia and Aricanregions is o immediate concern to the Global Programme to Eliminate LymphaticFilariasis. At least 10 countries in the Arican Region are co-endemic or Loa

loa, and this precludes rapid geographical expansion o the programme because

treatment or lymphatic flariasis can cause unacceptable severe adverse events inpeople inected with Loa loa. Modifcations need to be made to the use o mass

drug administration or other sae treatments or countries where the diseases areco-endemic.

Fig. 5.14.1 Distribution and status o preventive chemotherapy or lymphatic flariasis, worldwide, 2008

Ongoing interventions

Interventions not started

Stopped interventions

Not required interventions

Non-endemic countries

Distribution o lymphatic flariasis is ocal in many countries. For the detailed epidemiological situation in countries, please reer to Preventive chemotherapy and transmission control databank.Geneva, World Health Organization, 2010 (available at: http://www.who.int/neglected-diseases/ preventive-chemotherapy/databank/en/index.html: accessed January 2009).



119


Fig. 5.14.2 Distribution o population requiring preventive chemotherapyor lymphatic flariasis, by WHO region, 2008

AFR – Arican / AMR – The Americas / EMR – Eastern Mediterranean / SEAR – South-East Asia / WPR – Western Pacifc

AFR30 %

SEAR65 %

WPR

3%

AMR1%

EMR1%

Fig. 5.14.3 Reported coverage o treatment (%) or lymphatic flariasis,by WHO region, 2004–2008

0

60

2004

Year

C o v e r a g e ( % )

AFR GlobalAMR EMR


SEAR WPR

50

40

30

20

10

2005 2006 2007 2008



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Morbidity

Episodes o acute adenolymphangitis and maniestations o chronic disease

– especially lymphoedema and elephantiasis o limbs, and hydrocoele – inict

hardship on aected people. Daily chores, occupational activities, educational andemployment opportunities, and mobility are severely impaired. Te disfguremento limbs and genital parts leads to stigma, ridicule and psychological distress.

Marriage prospects and married lie are adversely aected by the disease.

Morbidity management to alleviate disease is a key component o the Global

Programme to Eliminate Lymphatic Filariasis. Simple hygiene measures and othermeasures reduce the requency o acute episodes and improve lymphoedema.

Surgical intervention or hydrocoele is eective and is being oered in more

communities. Although 23 countries are implementing case-management

programmes, other priorities remain including increasing advocacy, mobilizing

resources and orientating health services to make morbidity management andsurgical acilities more accessible.

In women the prevalence o lymphoedema and elephantiasis is higher and theimpact o disfgurement and disability is more serious. Te disease impairs theirwork and societal roles, which leads to dependence on amily and reductions

in income and health-seeking opportunities. Women are oen discriminated

against by the amily, community and health acilities, and they experience socialisolation and emotional and psychological problems (3). Psychosocial counsellingand education on coping should be promoted as part o morbidity management

programmes.


Te Global Programme to Eliminate Lymphatic Filariasis, which emphasizes

the mass distribution o medicines and was launched in 2000 ollowing the

adoption o World Health Assembly resolution WHA50.29 in 1997, has enabled

many countries to make antiflarial medicines available ree to millions o people.Annual mass chemotherapy delivered or 5–6 years is expected to interrupt

transmission in many settings and eliminate lymphatic flariasis as a public-healthproblem. China and the Republic o o Korea made concerted eorts and declared,in May 2007 and March 2008, respectively, to have eliminated the disease as a

public-health problem (4). At least 9 more countries (the Maldives, Sri Lanka

and Tailand in the South-East Asia Region; and the Cook Islands, Kiribati,

Malaysia, Niue, onga and Vanuatu in the Western Pacifc Region) have achievedsae threshold levels o prevalence or microflaraemia and thus may not require

urther interventions. Some geographical areas o Burkina Faso, the Comoros,

Egypt, Ghana, India, the Philippines and ogo have completed implementation

o more than 5 rounds o mass drug administration and achieved signifcant

reductions in the prevalence o microflaraemia prevalence (2). Te disease burden



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is declining in some regions and countries. Improvements in socioeconomic

status and the extensive use o personal protection measures against mosquitoesin some countries as well as the use o insecticide-treated bednets or malaria

control in parts o Arica are all expected to reduce exposure to transmission and

prevalence.In many settings, children born aer the initiation o mass drug administration

programmes remain ree rom microflaraemia, though a small proportion

display circulating antigenaemia and antibodies. Estimates suggest that mass drugadministration carried out under the Global Programme to Eliminate LymphaticFilariasis during 2000–2008 has prevented 8.46 million children aged less than 9years rom acquiring the inection, o which 1.76 million would have developed

hydrocoele, 1.06 million would have developed lymphoedema and 5.67 million

would have remained subclinical. By 2008, the number o people targeted by

mass drug administration programmes had reached 695 million, o whom an

estimated 5.63 million thus did not develop hydrocele and 3.38 million did notdevelop lymphoedema. Preventing disease in all age groups translates to averting32.46 million DALYs. Mass drug administration oers communities a variety

o ancillary benefts. O the 2.45 billion treatments delivered by the end o 2008,

828 million included albendazole together with diethylcarbamazine or ivermectinthereby preventing and curing other helminthiases, and 63.5 million preschool-

aged and school-aged children were treated in 2008 3).

Te geographical and population coverage o mass drug administration

programmes has been steadily increasing since the Global Programme to EliminateLymphatic Filariasis began. By 2009, 53 endemic countries were implementing

mass drug administration. Te number o people treated has increased rom 10million in 2000 to 546 million in 2007. By the end o 2008, a total o 2.45 billion

treatments had been delivered to populations where the disease is endemic (5), andthis number was approximately 3 billion at the end o 2009. Since 2005, 32–42% o the at-risk population has been treated every year Figure 5.14.3). Te proportionand size o the population treated through mass drug administration are likely tobe stable at around 35–40% and in the range o 450 million–550 million during

the next 3–4 years. Te cost o mass drug administration is cheap at US$ 0.05–0.10per person; the cost o DALY averted per person is US$ 5.90, suggesting that the

programme has an advantageous cost–beneft ratio 6 , 7 ).

Te timely supply and procurement o medicines o assured quality continuesto be an operational priority or the Global Programme to Eliminate Lymphatic

Filariasis. Te programme will continue its advocacy to strengthen its partnerships,mobilize resources, integrate with programmes to control other NDs and

provide support or research. Te next decade o the programme will be crucial

and it will need to be initiated in more countries. Mass drug administration willneed to be sustained in the countries where it has been implemented; countries

on the verge o stopping mass drug administration will need to maintain their

surveillance activities.



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Assessment

Te Global Programme to Eliminate Lymphatic Filariasis, which is based

on regularly delivering donated medicines, remains a vital player in eorts to

control lymphatic flariasis and interrupt its transmission. Despite signifcantsuccesses, the date when the goal o eliminating lymphatic flariasis as a public-

health problem as set by the World Health Assembly resolution WHA50.29 will

be attained cannot be predicted. In many places, lymphatic flariasis persists as apublic-health problem.

REFERENCES

1. Michael E, Bundy DAP. Global mapping o lymphatic ilariasis. Parasitology oday, 1997, 13:472–476.

2. Global programme to eliminate lymphatic ilariasis: progress report on mass drug administration in 2008. Weekly


3. WHO preventive chemotherapy and transmission control databank. Geneva, World Health Organization, 2010

(http://www.who.int/neglected_diseases/preventive_chemotherapy/databank/en/index.html; accessed July 2010).

4. Global Programme to eliminate lymphatic ilariasis: progress report on mass drug administration in 2007. Weekly

Epidemiological Record, 2008, 37/38:333–348.

5. Person B et al. Health-related stigma among women with lymphatic ilariasis rom the Dominican Republic and

Ghana. Social Science and Medicine, 2009, 68:30–38.

6. Ramaiah KD, Das PK. Mass drug administration to eliminate lymphatic ilariasis in India. rends in Parasitology,

2004, 20:499–502.

7. Ottesen EA et al. he global programme to eliminate lymphatic ilariasis: health impact ater 8 years. PLoS Neglected

ropical Diseases, 2008, 2(10):e317.

© W

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Triple drug administration in Zanzibar:

health worker recording treatment

with albendazole, ivermectin and

praziquantel dispensed to villagers

living in areas co-endemic or

lymphatic flariasis, schistosomiasis

and soil-transmitted helminthiases.



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5.15 Onchocerciasis (river blindness)

AbstractOnchocerciasis is a disease o the skin and eyes caused by a species o flarial

nematode (Onchocerca volvulus); it is transmitted by blackies. Te disease was

brought under control in west Arica through the work o the Onchocerciasis

Control Programme (1974–2002). Te programme relieved 40 million people rominection, prevented blindness in 600 000 and ensured that 18 million children

were born ree rom the threat o the disease and blindness, thus contributing tothe generation o 1 million years o productive labour.

DescriptionOnchocerciasis, or river blindness, is a parasitic disease caused by a flarial

worm (Onchocerca volvulus); it is transmitted to humans through the bite o

inected blackies that breed in ast-owing rivers. Te disease causes severe

visual impairment, including permanent blindness, and can shorten lie

expectancy by up to 15 years. Other eects include skin nodules and onchocercalskin disease, which is characterized by skin lesions (severe itching, dermatitis

and de-pigmentation). Severe itching alone is estimated to account or 60% o thedisease burden.

Onchocerca volvulus is transmitted by vector blackies o the genus Simulium,whose larvae and pupae develop in rapid-owing, well oxygenated streams and

rivers. During blood-eeding, inected blackies deposit inective larvae, which

enter the body; the larvae reach maturity aer about a year but may live as long

as 14 years. Te adult worms in the fbrous nodules o subcutaneous tissue then

mate, and emales produce microflariae that migrate to the skin, eyes and otherorgans. Tousands o microflariae eventually die in the body, provoking the

inammatory tissue reactions responsible or the disease.

DistributionMore than 99% o people inected with O. volvulus live in 30 endemic countries

in the Arican Region; the remainder live in Yemen and 6 countries o the Regiono the Americas (the Bolivarian Republic o Venezuela, Brazil, Colombia, Ecuador,Guatemala and Mexico) Figure 5.15.1, Figure 5.15.2). In 1995, 17.7 million peoplewere estimated to be inected, o whom about 270 000 were blind and 500 000

were visually impaired (1). Inormation rom rapid epidemiological mapping

o onchocerciasis and two cross-sectional studies o the long-term impact o

the work o the Arican Programme or Onchocerciasis Control indicate that

these numbers are higher, with nearly 42 million inected people in 1995 and

385 000 who were blind. Furthermore, there were 944 000 cases o low vision and13.1 million cases o severe itching 2).



124



Te Onchocerciasis Control Programme in west Arica was launched in 1974

with the objective o eliminating onchocerciasis as a disease o public-health

importance and an obstacle to socioeconomic development in 7 west Arican

countries. Control was based on aerial application o insecticides to kill the

larvae o the vector in riverine breeding sites. Destroying the vector to interrupt

transmission needed to continue or about 14 years, since that is the estimated

liespan o the adult worm. Following the donation o ivermectin, mass treatmentwas included in the Onchocerciasis Control Programme’s activities as an adjunct

to vector control or as the sole control measure, particularly when the programmewas expanded to include 4 additional countries in 1989 (3). Te programme was

successully concluded in 2002, although concerns remained about possible

recrudescence o onchocerciasis through re-invasion by inected blackies ormigration o inected people in the extended programme area o 11 west Arican

countries; hence the need or the countries to maintain eective surveillance 4).

Te Arican Programme or Onchocerciasis Control was launched in 1995 withthe objective o controlling onchocerciasis in the remaining endemic countries

in Arica by establishing sel-sustaining community-directed treatment with

ivermectin. By the end o 2009, 11 600 villages have been surveyed in 19 countriesusing mapping to determine levels o endemicity. In Mali and Senegal, sustained

high coverage o ivermectin alone has eliminated transmission o O. volvulus

in some oci (5). Te Arican Programme or Onchocerciasis Control is also

charged, where possible, with eliminating the vector – and hence the disease –

rom careully selected isolated oci using environmentally sae insecticides. able

5.15.1 summarizes the achievements o the Onchocerciasis Control Programme inwest Arica and the Arican Programme or Onchocerciasis Control.

he Onchocerciasis Elimination Program or the Americas is a regional

initiative that aims to eliminate morbidity related to the disease and interrupt

transmission in 6 endemic countries (the Bolivarian Republic o Venezuela, Brazil,

Colombia, Ecuador, Guatemala and Mexico), which is distributed in 13 oci.Te programme’s strategy encourages endemic countries to sustain mass drug

treatment with ivermectin every 6 months and aim to reach at least 85% o the

500 000 people at risk o the disease. By the end o 2007, all 6 endemic countries

had established eective national programmes in all 13 oci and had treatment

coverage o at least 85% twice a year. No new cases o blindness attributable to

onchocerciasis have been reported in the Region o the Americas, where eye

lesions due to onchocerciasis have been eliminated in 9 o the 13 oci.



125


Donations o ivermectin have enabled onchocerciasis control to proceed

in endemic countries where vector control was impractical, so the Arican

Programme or Onchocerciasis Control was established. Its strategy using

community-directed treatment with ivermectin empowers local communities

rather than health services to direct the treatment process (6 ). Communities

decide whether they want treatment, how to collect and distribute tablets, and howto monitor and record coverage. Health workers provide training and supervision.More than 120 000 communities have responded to this approach and, in 2008,

56.7 million people received ivermectin (Table 5.15.1) rom nearly hal a millioncommunity-directed distributors. Te cost per treatment is estimated at US$ 0.58compared with saving US$ 7 per DALY averted. Table 5.15.2 shows reductions in

the prevalence o O. volvulus inection and onchocerciasis in areas where in the

Arican Programme or Onchocerciasis Control has used community-directed

treatment; the table also shows that the cumulative number o DALYs gained has

risen since the project began. A rapid positive impact on human health has been

achieved 2).



126


Fig. 5.15.2 Distribution o population requiring preventive chemotherapyor onchocerciasis, by WHO region, 2008

AFR – Arican / AMR – The Americas / EMR – Eastern Mediterranean

AFR95 %

AMR1%

EMR4%

Table 5.15.1 Summary o achievements o the Onchocerciasis Control Programme(OCP) in west Arica and the Arican Programme or Onchocerciasis Control (APOC),1974–2008

OCP achievements (1974–2002) APOC achievements (1996–2008)

40 million people in 11 countries ree rom inection and eye

lesions20 million cases o severe itching prevented

600 000 cases o blindness prevented 500 000 cases o blindness prevented

18 million children born ree o the threat o blindness and

debilitating skin disease120 000 communities mobilized

1 million years o productive labour generated in participating

nations

Workorce o 748 000 community-directed distributors o

treatment trained and available or other programmes

25 million hectares o abandoned arable land reclaimed or

settlement and agricultural production, capable o eeding 17

million people annually

56.7 million people treated in 2008

Economic rate o return o 20%

Economic rate o return o 17%

850 000 DALYs averted per year

Cost o US$ 7 per DALY averted



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Te eort to overcome the public-health signifcance o onchocerciasis willdepend on (i) maintaining high treatment coverage with ivermectin during theliespan o the adult worm, Onchocerca, (ii) supporting government ownershipto sustain high treatment coverage (in 2006, governments o 13 APOC countries

reported disbursing more than US$ 1 million annually to support corecommunity-directed treatment activities) (7 ) and (iii) establishing community-directed treatment in post-conict countries to help strengthen weakened health

inrastructure and depleted human resources.

Fig. 5.15.3 Reported coverage o treatment (%) or onchocerciasis,by WHO region, 2005–2008

0

90

2005

Year

C o v e

r a g e ( % )

AFR Global

80

70

60

50

4030

20

10

AMR EMR

AFR – Arican / AMR – The Americas / EMR – Eastern Mediterranean

2006 2007 2008

Table 5.15.2 Estimated number o people with Onchocerca volvulus inection and clinical maniestations oonchocerciasis in 1995 beore the establishment o the Arican Programme or OnchocerciasisControl (APOC) and during its operations in 2006 and 2008

During APOC’s operations

Condition or maniestation Beore (1995) 2006 2008

Inection 41 894 000 30 724 000 25 719 000

Blindness 385 000 302 000 265 000

Low vision 944 000 809 000 746 000

Severe itching 29 700 000 6 285 000 4 186 000

Cumulative DALYs gained NA* 3 850 000 5 840 000

*NA, not applicable.



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REFERENCES

1. Onchocerciasis and its control. Report o a WHO Expert Committee on Onchocerciasis

Control . Geneva, World Health Organization, 1995 (WHO echnical Report Series, No.

852).

2. Habbema JDF. Health impact assessment [unpublished report]. Erasmus University,

Rotterdam and APOC, 2008 (available rom the WHO Department o Control o

Neglected ropical Diseases).

3. wenty years o onchocerciasis control. Review o the work o the Onchocerciasis Control

Programme in West Arica rom 1974 to 1994 [internal report]. Geneva, World Health

Organization, 1995 (available rom the WHO Department o Control o Neglected

ropical Diseases).

4. Sauerbrey M. he Onchocerciasis Elimination Program or the Americas (OEPA). Annals

o ropical Medicine and Parasitology, 2008, 102(Suppl. 1):S25–S29.

5. Diawara L et al. Feasibility o onchocerciasis elimination with ivermectin treatment in

endemic oci in Arica: irst evidence rom studies in Mali and Senegal. PLoS Neglected

ropical Diseases, 2009, 3(7):e497. doi:10.1371/journal.pntd.0000497 .

6. Amazigo UV et al. he challenges o community directed treatment with ivermectin

(CDI) within the Arican Programme or Onchocerciasis Control (APOC). Annals o

ropical Medicine and Parasitology, 2002, 96(Suppl. 1):S41–S58.

7. hirteenth Session o the Joint Action Forum, Brussels, Belgium, 4–7 December 2007 [inal

communiqué]. Ougadoudou, Arican Programme or Onchocerciasis Control, 2007. © W

H O

A community drug distributor carrying ivermectin and a

dose-pole during an onchocerciasis treatment campaign

is making her way to a remote village in Cameroon.

Assessment

Onchocerciasis control in the Arican Region is now the responsibility o o theArican Programme or Onchocerciasis Control, which was established in 1995.

By 2008, 56.7 million people had been treated at a cost o US$ 0.58 per treatment.In the Region o the Americas, the onchocerciasis elimination programme is

working to control the inection and development o the disease in the remainingendemic countries.



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5.16 Schistosomiasis (bilharziasis)

AbstractSchistosomiasis is now largely conined to sub-Saharan Arica where an

estimated 90% o the cases occur. More than 60% o the global burden is confnedto 10 countries in WHO’s Arican Region. In the other regions, the disease in

humans has been successully controlled or eliminated.

Description

Schistosomiasis, one orm o which is also known as bilharziasis, is a parasitic

disease that leads to chronic ill health 1). People inected with schistosomes expel

the parasite’s eggs in their aeces or urine. In villages or communities withoutproper latrines or sanitation, reshwater resources around the village or community may easily become contaminated with aeces or urine containing the eggs. Whenthey come in contact with water, the eggs hatch and release larvae called miracidia.I the miracidia fnd the right type o snail, they use it to multiply in several cycles,eventually producing thousands o new parasites, called cercariae, which are thenreleased rom the snail into the surrounding water. Humans become inected

when they come into contact with skin-penetrating cercariae in water. A child whohas suered persistent and heavy inections is likely to have chronic, irreversible

disease later in lie, such as liver fbrosis, cancer o the bladder or kidney ailure.

Schistosomiasis is characterized as either intestinal or urogenital, depending onwhere the adult ukes are located. Four species o schistosomes cause the intestinalorm (Schistosoma intercalatum, S. japonicum, S. mansoni, S. mekongi); in this

orm the adult worms occupy mesenteric veins, and their eggs pass into the lumeno the intestine and reach the aeces. Adult S. haematobium, which cause urogenitalschistosomiasis, reside in veins draining the urinary tract, and their eggs normally pass out o the body in the urine. Adult schistosomes are sometimes ound in sitesother than the intestines or urogenital tract.

Schistosomiasis is diagnosed by identiying specifc eggs using parasitological

methods, identiying haematuria (or S. haematobium), or detecting antibodiesor antigens in biological uids. Imaging techniques are used to detect pathology.

Because haematuria is a characteristic o urogenital schistosomiasis, especially inschool-aged children, asking people whether they have had blood in their urine canbe used to detect communities with a high prevalence o inection.

An estimated 207 million people may have schistosomiasis (2). Population growthand the increasing demand or water leads to developments that result in increasedtransmission and a changing epidemiology o the inection and disease 3).



131


Fig. 5.16.2 Distribution o population requiring preventive chemotherapyor schistosomiasis, by WHO region, 2008


AFR90.48 %

SEAR0.01%

WPR0.56%

AMR3.02%

EMR5.93%



132


MorbidityTe burden o disease caused by schistosomiasis continues to be debated. In

2004, WHO estimated that morbidity caused an equivalent o 1.7 million DALYs7 ). Te disability weight o 0.5% used in WHO’s calculations or the average caseo inection may be an underestimate; others have estimated greater disability weights 8).

Schistosomiasis results in severe organ pathology, anaemia, malnutrition,

stunted growth, impaired cognitive development and reduced capacity to work (9). Chronic intestinal schistosomiasis progresses rom abdominal pain andbloody diarrhoea to hepatosplenomegaly, periportal liver fbrosis and portal

hypertension. Urogenital schistosomiasis, which results in haematuria, dysuria,hydronephrosis, calcifcation o the bladder and other serious sequelae, is alsoassociated with bladder cancer 10) and an increased risk o HIV inection 11).

Te extent o mortality caused by schistosomiasis remains unclear. Using cause-specifc reports WHO estimated that 41 000 people die each year (7 ). Analysis o

data rom sub-Saharan Arica about the relationship between schistosomiasis and

specifc morbidity were used to estimate that mortality could be as high as 280 000

per year in the Arican region 12). Brazil has demonstrated that implementation o control activities leads to a notable decline in schistosomiasis-related mortality (13).

Economic impactTe economic benefts o schistosomiasis control are di cult to quantiy,

but gains in productivity have resulted rom treatment. A study carried outin Cambodia quantiied the productivity gained as a result o the national

schistosomiasis control programme implemented rom 1995 to 2006 (14).

Fig. 5.16.3 Number o people treated or schistosomiasis andreported coverage o treatment (%), by WHO region,

0

20

2006

Year

N u m b e r o f p e o p l e t r e a t e d ( m i l l i o n s )

AFR GlobalAMR EMR

AFR – Arican / AMR – The Americas / EMR – Eastern Mediterranean / WPR – Western Pacifc

WPR

C o v e r a g e ( % )

10

2007 2008

18

1614

12

10

8

6

4

2

8

6

4

2

2006–2008



134


REFERENCES

1. Gryseels B et al. Human schistosomiasis. Lancet , 2006, 368:1006–1018.

2. Steinmann P et al. Schistosomiasi s and water resources development: systematicreview, meta-analysis, and estimates o people at risk. Lancet Inectious Diseases,

2006, 6:411–425.3. alla I et al. Outbreak o intestinal schistosomiasis in the Senegal River Basin [in English].

Annales de la Société Belge de Médecine ropicale, 1990, 70:173–180.

4. Chitsulo L et al. he global status o schistosomiasis and its control. Acta ropica, 2000,77:41–51.

5. Wang LD et al. A strategy to control transmission o Schistosoma japonicum in China.

New England Journal o Medicine, 2009, 360:121–128.

6. Sinuon M et al. Control o Schistosoma mekongi in Cambodia: results o eight years o

control activities in the two endemic provinces. Transactions o the Royal Society o

Tropical Medicine and Hygiene, 2007, 101:34–39.

7. The global burden o disease: 2004 update. Geneva, World Health Organization,

2008.8. King CH, Dickman K, isch DJ. Reassessment o the cost o chronic helmintic inection:

a meta-analysis o disability-related outcomes in endemic schistosomiasis. Lancet , 2005,365:1561–1569.

9. King CH, Dangerield-Cha M. he unacknowledged impact o chronic schistosomiasis.

Chronic Illness, 2008, 4:65–79.

10. Parkin DM. he global burden o urinary bladder cancer. Scandinavian Journal o

Urology and Nephrology, 2008, 42(Suppl. 218):S12–S20.

11. Kjetland EF et al. Association between genital schistosomiasis and HIV in rural

Zimbabwean women. AIDS, 2006, 20:593–600.

12. van der Wer MJ et al . Quantiication o clinical morbidity associated with schistosome

inection in sub-Saharan Arica. Acta Tropica, 2003, 86:125–139.

13. Amaral RS et al. An analysis o the impact o the Schistosomiasis Control Programme in

Brazil [in English]. Memórias do Instituto Oswaldo Cruz , 2006, 101(Suppl. 1):S79–S85.

14. Croce D et al. Cost-eectiveness o a successul schistosomiasis control programme in

Cambodia (1995–2006). Acta Tropica, 2010, 113:279–284.

15. Brooker S et al. Cost and cost-eectiveness o nationwide school-based helminthcontrol in Uganda. Health Policy and Planning , 2008, 23:24–35.

16. Hotez PJ, Fenwick A. Schistosomiasis in Arica: an emerging tragedy in our new global

health decade. PLoS Neglected Tropical Diseases, 2009, 3(9):e485.

17. Gabrielli AF et al. A combined school- and community-based campaign targeting all

school-age children o Burkina Faso against schistosomiasis and soil-transmitted

helminthiasis: perormance, inancial costs and implications or sustainability. Acta

Tropica, 2006, 99:234–242.18. Kjetland EF et al. Prevention o gynecologic contact bleeding and genital sandy patches by

childhood anti-schistosomal treatment. American Journal o Tropical Medicine and

Hygiene, 2008, 79:79–83.

19. Allen HE et al. New policies or using anthelmintics in high risk groups. Trends in

Parasitology, 2002, 18:381–382.

20. WHO preventive chemotherapy and transmission control databank . Geneva, World Health

Organization, 2010 (http://www.who.int/neglected_diseases/preventive_chemotherapy/

databank/en/index.html; accessed July 2010).

© W

i l s o n ,

M

Children confrming haematuria (blood-urine) by show o

hands during a schistosomiasis (bilharziasis) education

session at a primary school in Bongo, Ghana.

Schistosomiasis causes anaemia, stunting and a reduced

ability to learn among children.



135


5.17 Soil-transmitted helminthiases

Abstract

More than 1 billion people are inected with the species o nematode that causesoil-transmitted helminthiases (SH). Te inections and the chronic morbidity

they cause persist wherever access to eective sanitation is lacking. Burkina Faso,Cambodia and the Lao People’s Democratic Republic have reached the World

Health Assembly’s target contained in resolution WHA54.19) o treating at least75% o school-aged children or the disease by 2010.

Description

Te our species o helminth sometimes occur concurrently in the same

community, resulting in people being inected with more than one species at atime. Also, inections are acquired rom an environment contaminated by the

worms’ inective stages, and so the species are oen considered collectively as i

they are a single entity. Consequently SH may be used to mean soil-transmittedhelminth, soil-transmitted helminth inection or soil-transmitted helminthiases,without reerence to the species involved. Care should be taken to be precise

about the use o the abbreviation SH, especially in the context o health, where

SH could mean soil-transmitted helminthiases relating, say, to ascariasis, or

soil-transmitted helminthiases relating to ascariasis and trichuriasis in the samepatient. Each species is responsible or a separate set o signs and symptoms, in

act or a separate disease. Hookworms ( Ancylostoma duodenale and Necator americanus) dier in their biology rom the common roundworm ( Ascaris

lumbricoides) and in the diseases they cause. Similarly, whipworm (Trichuris

trichiura) diers rom the others, as does the disease that it causes. Te conventiono reerring to the disease caused by hookworms as “hookworm disease” seems

to have arisen because the identifcation o the species o hookworm on the basiso eggs in stools is unreliable. In this report, the abbreviation SH reers to soil-

transmitted helminthiases.

People inected with soil-transmitted helminths pass parasite eggs in their

aeces. In areas where there is no latrine system, the soil and water around the

village or community becomes contaminated with aeces containing these eggs.

Te persistence o SH is closely linked to contamination o the environment

with the aeces o inected people. Te symptoms o soil-transmitted helminth

inections are nonspeciic and become evident only when the inection is

particularly severe. Symptoms include nausea, tiredness, abdominal pain and losso appetite. Tese inections aggravate malnutrition and ampliy rates o anaemia.Tey impede children’s physical growth and cognitive development, contributingsignifcantly to school absenteeism.



137


Fig. 5.17.1 Distribution o soil-transmitted helminthiases, worldwide, 2009

High (prevalence ≥50%)

Moderate (prevalence 20%–49%)

Low (prevalence <20%)


Non-endemic countries

Distribution o soil-transmitted helminthiases is ocal in many countries. For the detailed epidemiological situation in countries, please reer to Preventive chemotherapy and transmission control databank.Geneva, World Health Organization, 2010 (available at: http://www.who.int/neglected-diseases/ preventive-chemotherapy/databank/en/index.html: accessed January 2009).

Fig. 5.17.2 Distribution o population requiring preventive chemotherapyor soil-transmitted helminthiases, by WHO region, 2008


AFR24 %

SEAR41%

WPR9%

AMR12%

EMR14%

Four countries in the European Region are endemic. The population requiring preventive chemotherapy in these countries is <1% globallyand not represented in the chart.



138


Morbidity

Te main orm o morbidity caused by SH is the negative eect on nutritional

status (3). In addition the disease may cause cognitive impairment in children,

and complications requiring surgical intervention, such as intestinal and biliary

obstructions. Details on the morbidity caused by SH are presented in Table 5.17.2.

Fig. 5.17.3 Reported coverage o treatment (%) or soil-transmittedhelminthiases, by WHO region, 2004–2008

0

35

2004

Year

C o v e r a g e ( % )

AFR GlobalAMR EMR


SEAR WPR

30

25

20

15

10

5

2005 2006 2007 2008

Table 5.17.2 Morbidity associated with soil-transmitted helminth inectionsa

Type o morbidity Sign o morbidity Parasite Reerence

Nutritional impairment

Intestinal bleeding, anaemia Ancylostoma duodenale

Necator americanus 4

Malabsorption o nutrients Ascaris lumbricoides 6, 7

Competition or micronutrients Ascaris lumbricoides 8

Impaired growth Ascaris lumbricoides 9

Loss o appetite andreduction o ood intake

Ascaris lumbricoides 10

Diarrhoea or dysentery Trichuris trichiura 11

Cognitive impairment Reduction in uency and memory Trichuris trichiura 12, 13

Conditions requiringsurgical intervention

Intestinal and biliary obstructions Ascaris lumbricoides 5

Rectal prolapse Trichuris trichiura 14

a Adapted rom Montresor et al. (15 ).



139


Te prevalence and intensity o inection with Ascaris and Trichuris typically

reach a peak among children aged 5–14 years and subsequently decline among

adults. However, although heavy hookworm inections may occur in children, thepeak o their prevalence and intensity is commonly reported among those aged

30–44 years or even among people who are older than 50 (1). Soil-transmittedhelminthiases (especially hookworm) are particularly detrimental to the health

o childbearing women and on pregnancy outcomes owing to their impact on

nutrition, since they cause iron defciency and anaemia.

Economic impactA retrospective study based on data rom the Rockeeller Commission

evaluated the economic impact o eorts to control hookworm inection in the

southern United States; it ound that children cured o hookworm were 25% morelikely to attend school than untreated children, and having a hookworm-ree

childhood translated into earning 45% more income during adulthood (16 ). Te

impact produced by the nutritional and cognitive impairment associated with

these inections on the intellectual development and physical ftness o children

and adults, and consequently on work capacity and productivity, has been clearly highlighted 17 ).

Prevention and controlLack o access to sae water and proper sanitation are the main actors in the

persistence and prevalence o the disease. During the second hal o the 20th

century, the progressive improvement in standards o living in North America,

Europe and Japan has virtually eliminated SH there. More recently, a similar

trend has been observed in emerging economies in Asia, such as Malaysia and

the Republic o Korea. Te level o sanitation has not signifcantly improved in

the least-developed countries where these inections continue to cause signifcantmorbidity.

Control programmes in endemic countries have demonstrated that the

benefts o regular deworming are not limited to reducing direct morbidity.

School attendance, school results and productivity improve. An e cient way

to reach preschool-aged children or deworming treatment is to integrate this

treatment into vaccination campaigns organized or this age group. Te inclusiono deworming along with vaccination increases the coverage o the campaign.

More than 104 million preschool-aged children 20% o those in need o regulartreatment) are dewormed through vaccination campaigns, and coverage is

increasing.An equally e cient way to reach children o school age is through the school

system. Countries with ew resources but with strong political commitment (or

example, Burkina Faso, Cambodia and the Lao People’s Democratic Republic)

have achieved the target set by the World Health Assembly o treating 75% o

school-aged children by using schools as treatment centres.



140


Approximately 16% o school-aged children in need o regular treatment in

endemic countries (100 million children) receive periodic treatment. Recent

estimates report that it would cost US$ 33 000 to cover 1 million schoolchildren

(18). Despite the growth in coverage rates, the target o 75% coverage o the

world’s school-age children will not be reached unless implementation increasessignifcantly in order to take account o current needs and demographic growth.Figure 5.17.3).

Another important aspect to be considered is that one third o school-aged

children receive anthelminthic medicine through the Global Programme to

Eliminate Lymphatic Filariasis, which distributes albendazole together with

ivermectin or diethylcarbamazine. Once this programme eliminates lymphatic

flariasis in a community (normally aer 6 years o mass distribution o medicine),treatment at the population level is generally discontinued. Mechanisms to

maintain the anthelminthic distribution o benzimidazoles (albendazole or

mebendazole) aer the Global Programme to Eliminate Lymphatic Filariasis

ceases operating should be put in place so the advantages obtained by the

programme in controlling SH are not lost.

Assessment

Many countries where soil-transmitted helminthiases are endemic will not

attain the target set or 2010 by World Health Assembly resolution WHA54.19,

and adopted in 2001, to treat at least 75% o school-aged children. In 2008, 16%

o inected children were treated worldwide. In 2008, the Global Programme to

Eliminate Lymphatic Filariasis distributed albendazole as part o its treatmentor lymphatic ilariasis, thereby providing treatment or soil-transmitted

helminthiases to 65 million children. Tere will be a signifcant shortall in accessto medicine when this programme ends.

© W

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Distribution o mebendazole to school children in Bac Can province in Viet Nam. The use o the school inrastructure to deliver deworming

allows a low-cost distribution o drugs and ensures a higher rate o treatment.



141


REFERENCES

1. Hotez PJ et al. Rescuing the bottom bill ion through control o neglected tropical diseases.

Lancet , 2009, 373:1570–1575.

2. de Silva NR et al. Soil-transmitted helminth inections: updating the global picture.rends

in Parasitology, 2003, 19:547–551.

3. Hall A et al. A review and meta-analysis o the impact o intestinal worms on child growth

and nutrition. Maternal and Child Nutrition, 2008, 4(Suppl. 1):S118–S236.

4. Stoltzus RJ et al. Hemoquant determination o hookworm-related blood loss and its role

in iron deiciency in Arican children. American Journal o ropical Medicine and Hygiene,

1996, 55:399–404.5. de Silva NR, Chan MS, Bundy DA. Morbidity and mortality due to ascariasis: re-estimation

and sensitivity analysis o global numbers at risk. ropical Medicine and International

Health, 1997, 2:519–528.

6. Solomons NW. Pathways to the impairment o human nutritional status by gastrointestinal

pathogens. Parasitology, 1993, 107(Suppl.):S19–S35.

7. Crompton DW, Nesheim MC. Nutritional impact o intestinal helminthiasis during the

human lie cycle. Annual Review o Nutrition, 2002, 22:35–59.

8. Curtale F et al. Intestinal helminths and risk o anaemia among Nepalese children.

Panminerva Medica, 1993, 35:159–166.

9. aren DL et al. Contributions o ascariasis to poor nutritional status in children rom

Chiriqui Province, Republic o Panama. Parasitology, 1987, 95:603–613.

10. Stephenson LS et al. Physical itness, growth and appetite o Kenyan school boys with

hookworm, richuris trichiura and Ascaris lumbricoides inections are improved our

months ater a single dose o albendazole. Journal o Nutrition, 1993, 123:1036–1046.

11. Callender JE et al. Growth and development our years ater treatment or the richuris

dysentery syndrome. Acta Paediatrica , 1998, 87:1247–1249.

12. Nokes C et al. Parasitic helminth inection and cognitive unction in school children.

Proceedings o the Royal Society B: Biological Sciences , 1992, 247:77–81.

13. Kvalsvig JD, Cooppan RM, Connolly KJ. he eects o parasite inections on cognitive

processes in children. Annals o ropical Medicine and Parasitology, 1991, 85:551–568.

14. Intestinal protozoan and helminthic inections. Report o a WHO Scientiic Group. Geneva,

World Health Organization, 1981.

15. Montresor A et al. Helminth control in school age children: a guide or managers o control

programmes. Geneva, World Health Organization, 2002.

16. McGuire RA, Elman C.he prevalence o parasitic intestinal worms in the early twentieth-

century American south and their demographic and economic correlates [working paper].

Akron, OH, University o Akron, 2003.

17. Guyatt H. Do intestinal nematodes aect productivity in adulthood? Parasitology oday,

2000, 16:153–158.

18. Montresor A et al. Estimation o the cost o large-scale school deworming programmes

with benzimidazoles. ransactions o the Royal Society o ropical Medicine and Hygiene ,

2010, 104:129–132.



Global and regional plans or prevention and control Pa

6 Global and

regional plans

or prevention

and control

© W

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6.1 Health targets

Te Global plan to combat neglected tropical diseases 2008–2015 (1) was preparedby WHO aer deliberations among technical sta at headquarters and regional

oces, country representatives and their sta, and external experts. In keeping

with the Millennium Development Goals, the global plan aims to prevent, control,eliminate or eradicate NDs. Te targets or the plan’s period are:

to eliminate or eradicate those diseases targeted in resolutions o the WorldHealth Assembly and WHO’s regional committees;

to reduce signifcantly the burden o other diseases or which interventionsexist;

to ensure that novel approaches to treatment are available, promoted andaccessible or diseases that have ew treatments or control strategies.




Each o the nine strategic areas o the global plan proposes a series o actions tomeet specifc targets during 2008–2015. Te strategic areas or action are:

1. to assess the burden o NDs including zoonoses;

2. to develop integrated approaches and multi-intervention packages ordisease control;

3. to strengthen health-care systems and capacity building;

4. to ormulate evidence or advocacy to promote prevention, treatment andcontrol;

5. to ensure ree and timely access to high-quality medicines and diagnosticand preventive tools;

6. to improve access to innovation;

7. to strengthen the integration o vector management and veterinary public-health interventions at the human–animal health interace;

8. to consolidate partnerships and mobilize resources;

9. to promote an intersectoral, interprogrammatic approach to ND control.

Since the list o NDs presented in this report is not exhaustive, and has

regional and national variations, diseases need to be prioritized or action and

appropriate strategies should be developed or control. Some diseases can be

controlled with a multi-intervention package implemented on a large scale, whileothers require taking intensifed actions in ocus areas.

WHO’s regional oces have developed individual action plans to combat NDs,and each plan ocuses on regionally prioritized diseases. Regional specifcities andpriorities or prevention and control o NDs are set out below (able 6.1.1). Tereis no report rom the European Region since NDs have little direct public-healtheect on its countries, but the region should be mindul o the opportunities or

inections to travel as evidenced by the arrival o Chagas disease in southern

Europe see section 5.7).



Global and regional plans or prevention and control Pa

Table 6.1.1 Neglected tropical diseases given priority or prevention and control, by WHO

region and source o document

WHO region and source Priority diseases

Arican RegionAFRO workplan 2006–2007 (DDC/CPC)

Buruli ulcerDracunculiasisHuman Arican trypanosomiasisLeishmaniasisLeprosyLymphatic flariasisLoiasisOnchocerciasisSchistosomiasisSoil-transmitted helminthiases

Eastern Mediterranean RegionEMRO NTD control inter-country workplan 2006 –2007

DracunculiasisHuman Arican trypanosomiasisLeishmaniasisLeprosyLymphatic flariasis

Schistosomiasis and intestinal parasitic inectionsZoonotic cutaneous leishmaniasisZoonotic diseases (brucellosis, rabies, hydatidosis)

Region o the AmericasRegional strategic ramework or prevention and control oneglected diseases in neglected populations in Latin Americaand the Caribbean 2006–2020

Chagas diseaseDengueEchinococcosis (hydatidosis)FascioliasisHookworm diseaseLeishmaniasisLeprosyLymphatic flariasisOnchocerciasisOther soil-transmitted inectionsSchistosomiasisTaeniasis solium and cysticercosisTrachomaRabies

South-East Asia RegionSEARO workplan 2006–2007 (communicable diseaseprevention and control)

Dengue and dengue haemorrhagic everRabiesSoil-transmitted helminthiasesJapanese encephalitisLeishmaniasisLeprosyLymphatic flariasisTrachoma and leptospirosis Yaws

Western Pacifc RegionWPRO workplan 2006–2007 Malaria and other vector-borne and parasitic diseases inCambodiaDengue and dengue haemorrhagic everFoodborne trematodiasisLeprosyLymphatic flariasisSchistosomiasisSoil-transmitted helminthiasesRabies and zoonoses




6.2 Regional plans

WHO’s regional oces and the Member States they support have responded

to the global plan by developing regional plans to identiy how NDs can be

prevented and controlled in their regions. Copies o the regional plans rom theArican, Americas, Eastern Mediterranean and South-East Asia regions have beenpublished in electronic ormat and are attached to this report. Te report rom theWestern Pacifc Region, which has also been published electronically, is concernedonly with the prevention and control o dengue ever and dengue haemorrhagic

ever.

REFERENCE





Conclusions Pa

7 Conclusions

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his report is the frst o its kind to detail the work o WHO and its partnersin overcoming the global impact o neglected tropical diseases, work thatbegan during the early years o WHO. Te report contains quantitative

inormation and evidence about the global situation o NDs in the world

today, ocusing on progress made in overcoming the transmission o widely

prevalent pathogens and their associated morbidity and mortality in millions o

people. Although NDs are a diverse group o diseases, they share in common astranglehold on populations whose lives are ravaged by poverty. During the pastdecade, the wider international community has recognized that this situation is

unacceptable, and this recognition has stimulated the growth o a community o partners committed to bringing resources and expertise to the task o overcomingNDs.




WHO provides technical advice to governments and other organizations,

develops strategies or prevention and control, compiles quantitative inormationabout the distribution o NDs and the coverage and implementation o activities,and coordinates the work o its community o partners.

Evidence provided throughout this report demonstrates that steady progress isbeing made. Te eort is directed towards achieving the targets or ND controlset by the World Health Assembly that wil l in turn contribute to attaining the

Millennium Development Goals. Improvements in health will surely have a majorbenefcial impact on development. Onchocerciasis has declined in west Arica andis being tackled in the rest o the continent. Te prevalence o leprosy worldwidehas declined steadily. Schistosomiasis has been deeated in China. Dracunculiasisshould soon be eradicated. New public-health approaches or controlling NDs incommunities have been developed and are being implemented. Processes are beingstrengthened to acilitate assessment o the quality o medicines and procurement

management. A Strategic and echnical Advisory Group or NDs, reporting toWHO’s Director-General, has been established and has begun work. Millions o

people are now receiving treatment ree o charge with saety-tested medicines o assured quality. Many health workers in endemic countries have been trained inaspects o ND control, thereby strengthening national health systems.

We should not get carried away with success. Many challenges need attention

and action. Millions more people are in need o ree treatment with high-quality medicines. Millions more need care and treatment or rabies, echinococcosis,

leishmaniasis and other seemingly intractable NDs. Drug resistance may emergeas control interventions based on the distribution o medicines expand. Vector

control must be increased and coordinated, in many cases with water supply andwater development projects. In the long term, economic growth and stability willeventually ensure that sae water and sanitation are provided or all peoples: a

prerequisite or banishing NDs rom the human experience.

In April 2007, Dr Margaret Chan, WHO’s Director-General, addressed the NDpartners. She set out her vision or the uture o ND control and concluded: “Forthe frst time, we have a head start on these ancient companions o poverty. For

the frst time, more than 1 billion people le behind by socioeconomic progress

have a chance to catch up. I believe this is our shared ambition”.



Conclusions Pa

Overcoming neglected tropical diseases:

7 gains, 7 challenges

Gains

1. Recognition o the importance o global control o neglected tropical

diseases. A more reliable evaluation o the signifcance o NDs in terms o their impact on public health and economies has stimulated new thinkingin public health, leading to the adoption o ive strategic approaches orwidespread interventions. Tis evaluation has convinced governments, donors,the pharmaceutical industry and other agencies, including NGOs, to invest inND prevention and control.

2. Progress in prevention and control o neglected tropical diseases. Preventionand control activities or NDs have been included in the policies and budgetso many endemic countries. Tis has led to the development o interventionsappropriate to existing health systems, oen with the support o implementingpartners.

3. Increased commitment. Te development o plans by WHO’s regional ocesin response to the Global plan to combat neglected tropical diseases 2008–2015 (1) has led to growing awareness o NDs and the suering they cause.

4. Successul outcomes. Global eorts to control “hidden” diseases, such as

dracunculiasis, leprosy, lymphatic flariasis and yaws, have yielded progressivegains including the imminent eradication o dracunculiasis.

5. Regional success. Achievements in the control o Chagas disease, humanArican trypanosomiasis, onchocerciasis, schistosomiasis and trachoma havegenerated greater awareness and wider recognition o the disease burden thataects poor people.

6. Engagement with the pharmaceutical industry. Involvement o the industry with NDs and their subsequent donations to support control eorts haveincreased access to high-quality medicines ree o charge or hundreds o millions o poor people (able 7.1).

7. Expanded collaboration between partners. Te increasing willingness andcommitment o local and global communities o partners to work with endemiccountries have brought resources, innovation, expertise and advocacy to eortsto overcome NDs. Intersectoral collaboration involving education, nutritionand agriculture has reinorced ND control eorts (2).




Table 7.1 Major donations o medicines or controlling neglected tropical diseases made

by the pharmaceutical industry

Medicine Donation

Albendazole Unlimited supply or as long as needed rom GlaxoSmithKline or

lymphatic flariasis; donation made through WHO

Azithromycin Unlimited quantity rom Pfzer in the context o SAFE

Eornithine Unlimited quantity until 2012 rom sanof-aventis or human Arican

trypanosomiasis; donation made through WHO

Ivermectin Unlimited supply or as long as needed donated directly to countries by

Merck & Co., Inc., or lymphatic flariasis and onchocerciasis

Multidrug therapy (riampicin, cloazimine

and dapsone in blister packs) and loose

cloazimine

Unlimited supply or as long as needed or leprosy and its complications

rom Novartis; donation made through WHO

Mebendazole 50 million tablets annually rom Johnson & Johnson or soil-transmittedhelminthiases control programmes or children. From 2011, this will

increase to 200 million annually

Melarsoprol Unlimited quantity until 2012 rom sanof-aventis or human Arican


Niurtimox 900 000 tablets (120 mg) per year by 2014 rom Bayer or treatment

o Chagas disease and human Arican trypanosomiasis; donation made

through WHO

Pentamidine Unlimited quantity by 2012 rom sanof-aventis or human Arican


Praziquantel 200 million tablets during 2008–2017 rom Merck KGaA orschistosomiasis; donation made through WHO

Suramin Unlimited quantity by 2012 rom Bayer or human Arican


Triclabendazole From Novartis or ascioliasis; donation made through WHO

Challenges

1. Commitment o resources. Despite global economic constraints, support romthe United States, the United Kingdom, Spain, other countries, agencies andNGOs will need to be sustained, and this should encourage others to expand

their support or developing the services needed to overcome NDs.2. Declining relevant expertise. Expertise in individual NDs is lacking in some

countries or continues to decline. Te decline is most severe in vector control,case-management, pesticide management and veterinary aspects o publichealth. As expansion o prevention and control activities in endemic countriesincreases, the need will increase to strengthen health systems, and to train andsupport sta with technical and management expertise.



Conclusions Pa

3. Expanding use o preventive chemotherapy. argets or coverage set by theWorld Health Assembly or control o lymphatic flariasis, schistosomiasis,soil-transmitted helminthiases and trachoma will not be met, especially inthe Arican and South-East Asia regions, unless interventions with preventivechemotherapy increase.

4. Insufcient quantities o quality-assured medicines or neglected tropical

diseases. Donations o praziquantel rom the private sector and unds or itsproduction are insucient to meet the quantities o this essential medicineneeded to control schistosomiasis. For lymphatic flariasis, two o the threemedicines required (albendazole and ivermectin) are donated. he third(diethylcarbamazine citrate [DEC]) needs to be purchased. Te provision o medicines to treat soil-transmitted helminthiases needs also to be increasedsignifcantly. Production o medicines or NDs needs to become attractive tomanuacturers o generic drugs.

5. Targeted research or neglected tropical diseases. A research strategy isrequired to develop and introduce new medicines, notably or leishmaniasisand trypanosomiasis; new methods or vector control; vaccines or dengue; andnew diagnostics that will be accessible to all who need them.

6. Improved quantitative inormation systems. As control interventions reachmore people and new technologies are embraced, quicker responses will needto be made to inormation about the epidemiology, transmission and burden o NDs. Similarly, programme managers will need to react quickly to inormationabout the coverage, compliance, acceptance and impact o interventions.

7. Global changes. Planning or the development o prevention and controlmeasures or NDs should take into account the possible eects o porousborders, population growth and migration, the movements o livestock and

vectors, and the political and geographical consequences o climate change.

REFERENCES



2. Report o the global partners’ meeting on neglected tropical di seases. Geneva, World Health




Neglected tropical diseases in the world today An

Annexes




Annex 1. Resolutions o the World Health Assembly

(WHA) on neglected tropical diseases

Disease WHA resolutionnumber

Title Year

Vector-borne disease WHA1.12 Vector biology and control 1948

Vector-borne disease WHA2.18Expert Committee on insecticides: report on the frstsession

1949

Endemic treponematoses WHA2.36 Bejel and other treponematoses 1949

Leprosy WHA2.43 Leprosy 1949

Rabies WHA3.20 Rabies 1950

Trachoma WHA3.22 Trachoma 1950

Hydatidosis WHA3.23 Hydatidosis 1950

Schistosomiasis and soil-transmitted helminthiases

WHA3.26 Bilharziasis 1950

Vector-borne disease WHA3.43 Labelling and distribution o insecticides 1950

Trachoma WHA4.29 Trachoma 1951

Vector-borne disease WHA4.30 Supply o insecticides 1951


Vector-borne disease WHA5.29Supply and requirements o insecticides: world

position

1952

Leprosy WHA6.19 Expert Committee on leprosy: frst report 1953

Leprosy WHA9.45 Inter-regional conerence on leprosy control, 1958 1956

Vector-borne disease WHA13.54 Vector-borne diseases and malaria eradication 1960

Vector-borne disease WHA22.40 Research on methods o vector control 1969

Vector-borne disease WHA23.33 Research on alternative methods o vector control 1970

Research WHA27.52Intensifcation o research on tropical parasiticdiseases

1974

Leprosy WHA27.58 Coordination and strengthening o leprosy control 1974

Schistosomiasis WHA28.53 Schistosomiasis 1975

Avoidable blindness (or bothonchocerciasis and trachoma)

WHA28.54 Prevention o blindness 1975

Leprosy WHA28.56 Leprosy control 1975

Research WHA28.71WHO’s role in the development and coordination oresearch in tropical diseases

1975




Schistosomiasis WHA29.58 Schistosomiasis 1976



Research WHA30.42Special Programme or Research and Training inTropical Diseases

1977

Zoonoses WHA31.48Prevention and control o zoonoses and oodbornediseases due to animal products

1978

Endemic treponematoses WHA31.58 Control o endemic treponematoses 1978


Dracunculiasis WHA34.25International drinking-water supply and sanitationdecade

1981

Human Arican trypanosomiasis WHA36.31 Arican human trypanosomiasis 1983

Dracunculiasis WHA39.21 Elimination o dracunculiasis 1986

Leprosy WHA40.35 Towards the elimination o leprosy 1987

Dracunculiasis WHA42.25International Drinking Water Supply and SanitationDecade

1989

Dracunculiasis WHA42.29 Elimination o dracunculiasis 1989

Vector-borne disease WHA42.31 Control o disease vectors and pests 1989

Research WHA43.18 Tropical disease research 1990

Dracunculiasis WHA44.5 Eradication o dracunculiasis 1991


Dengue and dengue haemorrhagicever

WHA46.31 Dengue prevention and control 1993

Onchocerciasis WHA47.32Onchocerciasis control through ivermectindistribution

1994

Vector-borne disease WHA50.13Promotion o chemical saety, with special attentionto persistent organic pollutants

1997

Lymphatic flariasis WHA50.29Elimination o lymphatic flariasis as a public healthproblem

1997

Dracunculiasis WHA50.35 Eradication o dracunculiasis 1997

Human Arican trypanosomiasis WHA50.36 Arican tr ypanosomiasis 1997

Trachoma WHA51.11 Global elimination o blinding trachoma 1998

Chagas disease WHA51.14 Elimination o transmission o Chagas disease 1998

Leprosy WHA51.15 Elimination o leprosy as a public health problem 1998

DiseaseWHA resolution

numberTitle Year




Schistosomiasis and soil-transmitted helminthiases

WHA54.19Schistosomiasis and soil-transmitted helminthinections

2001

Dengue and dengue haemorrhagicever

WHA55.17Prevention and control o dengue ever and denguehaemorrhagic ever

2002

Human Arican trypanosomiasis WHA56.7Pan Arican tsetse and tr ypanosomiasis eradicationcampaign

2003


WHA56.26Elimination o avoidable blindness

2003

Buruli ulcer WHA57.1Surveillance and control o Mycobacterium ulcerans

disease (Buruli ulcer)2004

Human Arican trypanosomiasis WHA57.2 Control o human Arican trypanosomiasis 2004

Dracunculiasis WHA57.9 Eradication o dracunculiasis 2004Avoidable blindness (or bothonchocerciasis and trachoma)

WHA59.25Prevention o avoidable blindness and visualimpairment

2006

Leishmaniasis WHA60.13 Control o leishmaniasis 2007


WHA62.1Prevention o avoidable blindness and visualimpairment

2009

Chagas disease WHA63.20 Chagas disease: control and elimination 2010

DiseaseWHA resolution

numberTitle Year




Annex 2. Ofcial list o indicators or monitoring progress on

the Millennium Development Goals

Millennium Development Goals (MDGs)

Goals and targetsrom the Millennium Declaration

Indicators or monitoring progress

Goal 1: Eradicate extreme poverty and hunger

Target 1.A: Halve, between 1990 and 2015,the proportion o people whose income is lessthan one dollar a day

1.1 Proportion o population living on less than US$ 1 (PPP) per daya

1.2 Poverty gap ratio

1.3 Share o poorest quintile in national consumption

Target 1.B: Achieve ull and productive

employment and decent work or all, includingwomen and young people

1.4 Growth rate o gross domestic product per person employed

1.5 Employment-to-population ratio

1.6 Proportion o employed people living on less than US$ 1 (PPP) per day

1.7 Proportion o own-account and contributing amily workers in totalemployment

Target 1.C: Halve, between 1990 and 2015,the proportion o people who suer romhunger

1.8 Prevalence o underweight children aged less than 5 years

1.9 Proportion o population below minimum level o dietary energyconsumption

Goal 2: Achieve universal primary education

Target 2.A: Ensure that, by 2015, childreneverywhere, boys and girls alike, will be ableto complete a ull course o primary schooling

2.1 Net enrolment ratio in primary education

2.2 Proportion o pupils starting grade 1 who reach last grade o primaryschool

2.3 Literacy rate o 15–24 year-olds, women and men

Goal 3: Promote gender equality and empower women

Target 3.A: Eliminate gender disparity inprimary and secondary education, preerablyby 2005, and in all levels o education no laterthan 2015

3.1 Ratios o girls to boys in primary, secondary and tertiary education

3.2 Share o women in wage employment in the nonagricultural sector

3.3 Proportion o seats held by women in national parliament

Goal 4: Reduce child mortality

Target 4.A: Reduce by two thirds, between1990 and 2015, the under-fve mortality rate

4.1 Under-fve mortality rate

4.2 Inant mortality rate

4.3 Proportion o 1-year-old children immunized against measles

Goal 5: Improve maternal health

Target 5.A: Reduce by three quarters,between 1990 and 2015, the maternalmortality ratio

5.1 Maternal mortality ratio

5.2 Proportion o births at tended by skilled health personnel

Target 5.B: Achieve, by 2015, universalaccess to reproductive health care

5.3 Contraceptive prevalence rate5.4 Adolescent birth rate5.5 Antenatal care coverage (at least one v isit and at least our visits)5.6 Unmet need or amily planning




Target 8.C: Address the special needso landlocked developing countries andsmall island developing states (through theProgramme o Action or the Sustainable

Development o Small Island Developing Statesand the outcome o the twenty-second specialsession o the General Assembly)

Target 8.D: Deal comprehensively with thedebt problems o developing countries throughnational and international measures in order tomake debt sustainable in the long term

Market access

8.1 Proportion o total developed country imports (by value and excludingarms) rom developing countries and least-developed countries, admittedree o duty

8.2 Average taris imposed by developed countries on agricultural products,textiles and clothing rom developing countries

8.3 Agricultural support estimate or OECD countries as a percentage o theirgross domestic product

8.4 Proportion o o fcial development assistance provided to help build tradecapacity

Debt sustainability

8.5 Total number o countries that have reached their HIPC decision pointsand number that have reached their heavily indebted poor countriescompletion points (cumulative)

8.6 Debt relie committed under heavily indebted poor countries and MDRIinitiatives

8.7 Debt service as a percentage o exports o goods and services

Target 8.E: In cooperation with pharmaceuticalcompanies, provide access to a ordableessential drugs in developing countries

8.8 Proportion o population with access to aordable essential drugs on asustainable basis

Target 8.F: In cooperation with the privatesector, make available the benefts o newtechnologies, especially inormation andcommunications

8.9 Telephone lines/100 population

8.10 Cellular subscribers/100 population

8.11 Internet users/100 population

Te Millennium Development Goals and targets come rom the Millennium

Declaration, signed by 189 countries, including 147 heads o state and government,in September 2000 (http://www.un.org/millennium/declaration/ares552e.htm)

and rom urther agreement by Member States at the 2005 World Summit(Resolution adopted by the General Assembly, A/RES/60/1, http://www.un.org/

Docs/journal/asp/ws.asp?m=A/RES/60/1). Te goals and targets are interrelated

and should be seen as a whole. Tey represent a partnership between developed

countries and developing countries “to create an environment – at the national

and global levels alike – which is conducive to development and the elimination

o poverty”.

a o monitor poverty trends in countries, indicators based on national poverty lines should be used whereavailable.

b Te actual proportion o people living in slums is measured by a proxy, represented by the urbanpopulation living in households with at least one o the ollowing our characteristics: (a) lack o accessto improved water supply; (b) lack o access to improved sanitation; (c) overcrowding (3 or more peopleper room); and (d) dwellings made o non-durable material.



Neglected tropical diseases in the world today Ann

Annex 3. Summary o metadata (1) with relevant code or codes

rom the International statistical classifcation o dis-

eases and related health problems , 10th revision (2 )

5.1 Dengue and other arboviral diseases (A90, A91)

Global number o cases reported Dengue and other mosquito-borne viral evers (A90, A91, A92)

5.2 Rabies (A82.0, A82.1)

Risk categories or rabies are defnedbased on the likelihood o contractinghuman rabies in a given country or area

No risk: countries or areas that are considered rabies-ree (human and animalrabies historically not reported and/or not reported by surveillance in any animalspecies, domestic or wild)

Low risk: countries or areas with no dog-to-dog rabies transmission (becauseo dog control or elimination operations or because these areas were historicallyree o rabies in dogs) but with wildlie (wild-carnivore mediated and/or bat-mediated) rabies. Throughout these areas, human rabies biologics (vaccines andimmunoglobulin) and expertise to provide post-exposure prophylaxis are readilyavailable

Moderate risk: countries or areas with only sporadic cases o rabies in dogs andwildlie (wild carnivore-mediated and/or bat-mediated). In these areas, humanbiologics and expertise to provide post-exposure prophylaxis are mostly availablein major urban centres

High risk: countries or areas with sustained dog-to-dog rabies transmission and

no or little wildlie rabies (with the exception o the Amazonian orestwhere rabies in vampire bats is present and represents a high risk or humans).In these countries or areas, access to human biologics and expertise to providepost-exposure prophylaxis are usually very limited

5.3 Trachoma (A71)

Trachomatous inammation – ollicular(TF)

Trachomatous inammation – ollicular: defned as the presence o at least5 ollicles at least 0.5 mm in diameter in the central part o the upper tarsalconjunctiva ( 3 )

Trachomatous inammation – intense (T I)Trachomatous inammation – intense: defned as pronounced inammatorythickening o the upper tarsal conjunctiva obscuring more than hal the normal

deep tarsal vessels ( 3 )

Endemic

Countries with communities where the prevalence o active trachoma in childrenaged 1–9 years is greater than 10% or where the prevalence o trichiasis inpeople aged 15 years or older is 1% and where trachoma elimination activitiesare required

Non-endemic Countries not requiring implementation o trachoma elimination activities




5.12 Cystic echinococcosis (hydatidosis) (B67)

Probably absentCountries or territories with no confrmed identifcations or reports oEchinococcus granulosus in indigenous domestic or wild animal populations.Human cystic echinococcosis (hydatidosis) has not been reported

SuspectedE. granulosus may not be recorded in ofcial data or publications, but may occurin wildlie and possibly at low prevalence in domestic animals. Human cysticechinococcosis (hydatidosis) appears not to occur

Rare/SporadicE. granulosus has been recorded at low prevalence in domestic animals and maybe transmitted in wildlie populations. Human cystic echinococcosis (hydatidosis)cases are only occasionally reported

PresentE. granulosus is known to be endemic in at least some areas o the country.Domestic animal (and possibly wildlie) and human cystic echinococcosis(hydatidosis) occur regularly

High endemicity areas

The defnition applies only to areas within a specifed endemic country.High endemicity areas involve ≥1 state, region, province or districtwhere E. granulosus prevalence in dogs exceeds 5-10% and where theprevalence o human cystic echinococcosis (hydatidosis) is greaterthan 1–5 cases/100 000 inhabitants annually

5.13 Foodborne trematodiasis (B66.0, B66.1, B66.3, B66.4) – ascioliasis

CasesActively or passively reported cases o ascioliasis, detected clinically orparasitologically

5.14 Lymphatic flariasis (B74.0, B74.1, B74.2)

Ongoing interventions Endemic country implementing mass drug administration

Interventions not startedEndemic country that has not commenced implementation o mass drugadministration

Interventions stopped ater achievingmicroflaraemia prevalence rate less than1%

Endemic country where the microflaraemia rate has decreased to less than 1%and mass drug administration has been stopped

Not requiring interventions Historically endemic where no mass drug administration is required

Non-endemic Country not previously endemic

5.15 Onchocerciasis (B73)

Endemic Cases o onchocerciasis have been detected previously

Non-endemic No cases o onchocerciasis have been detected previously




HypoendemicCountry with onchocercal nodule prevalence rates less than 20% and whereindividuals are treated on a clinical basis

MesoendemicCountry with onchocercal nodule prevalence rates o 20–39% and wherepreventive chemotherapy is required

HyperendemicCountry with onchocercal nodule prevalence rates greater than 39% and wherepreventive chemotherapy is required

5.16 Schistosomiasis (B65.0, B65.1, B65.2, B65.8)

Non-endemic No parasitiologically confrmed cases o schistosomiasis detected or reported.

Low risk o morbidityParasitiologically confrmed cases reported, with prevalence less than 10% inaected areas and preventive chemotherapy is not required

Moderate risk o morbidityParasitiologically confrmed cases reported, with prevalence o 10% or higher butless than 50% in a ected areas and preventive chemotherapy is required

High risk o morbidityParasitiologically confrmed cases reported, with prevalence 50% or higher inaected areas and preventive chemotherapy is required

5.17 Soil-transmitted helminthiases (B76.0, B76.1, B77, B79)

Non-endemic No parasitologically confrmed soil-transmitted helminths reported

Low risk o morbidityParasitologically confrmed cases reported, prevalence is less than 20% inaected areas and preventive chemotherapy is not required

Moderate risk o morbidity

Parasitologically confrmed cases reported, with prevalence 20% or higher but

less than 50% in a ected areas and preventive chemotherapy is required

High risk o morbidityParasitologically confrmed cases reported, with prevalence 50% or higher inaected areas and preventive chemotherapy is required

REFERENCES

1. For clinical descriptions and case defnitions, see WHO recommended strategies or the

prevention and control o communicable diseases. Geneva, World Health Organization,

2001 (WHO/CDS/CPE/SM/2001.13).

2. International Statistical Classifcation o Diseases and related health problems , 10th

revision, ICD-10, 2008 edition. Geneva, World Health Organization, 2009.

3. rachoma control: a guide or programme managers. Geneva, World Health Organization,

2006.




Annex 4. Methods used to prepare maps and charts

Population

Te total population o each country is taken rom World population prospects:

2009 revision (1). Te population o children aged 1–4 years and 5–14 years is

also given in some cases since these are the age groups specifcally targeted or

anthelminthic treatments.

Preventive chemotherapy dataUnless otherwise specifed, data on preventive chemotherapy are as provided by

national authorities to WHO through reporting processes in country and regionaloces using standardized templates. Maps and charts or lymphatic flariasis,

soil-transmitted helminthiases, schistosomiasis, onchocerciasis and trachoma

were prepared using data routinely reported to WHO annually. Inormation romthe preventive chemotherapy databank was used to compile sections o this reportand is accessible online 2).

Te main defnitions o data used to describe preventive chemotherapy are as

ollows.

Population requiring preventive chemotherapy : the total population

living in all endemic areas who require preventive chemotherapy.

Geographical coverage: the proportion (%) o endemic districts covered

by preventive chemotherapy.

Programme coverage: the proportion (%) o individuals who were treatedaccording to the programme’s target.

National disease-specifc coverage: the proportion (%) o individuals in

the population requiring preventive chemotherapy or the specifc disease

that has been treated.

Dracunculiasis data are as reported weekly to WHO by national authorities

that provide updates on the status o the eradication initiative at the country levelas well as related epidemiological inormation.

Fascioliasis data are based on inormation obtained rom peer-reviewed

publications and supplemented by the opinions o international experts.




Data on innovative and intensifed disease management

Data or neglected tropical diseases where the large-scale use o existing tools

is limited have been obtained by various non-integrated methods that depend onthe particularities o the disease control programme.

Chagas disease: data ocially reported to WHO as ocial estimates

endorsed through a consultative process between national authorities andinternational experts.

Buruli ulcer: annual data routinely reported to WHO by national

authorities using a standardized reporting template.

Endemic syphilis: historical data and ad hoc inormation reported to

WHO by national authorities and researchers.

Human Arican trypanosomiasis: data routinely reported to WHO

annually by national authorities using a standardized reporting template. Leishmaniasis: ad hoc inormation made available to WHO by programme

managers and researchers.

Leprosy: data routinely reported to WHO annually by national authoritiesusing a standardized reporting template.

Zoonoses data

Rabies: data were obtained rom RabNet and other sources. RabNet is a WHO-led interactive inormation system that is able to generate interactive maps and

graphs using data on rabies in humans and animals. Tis online data collection

system collects data electronically on a yearly basis 3).

Cysticercosis: data are based on inormation obtained rom peer-reviewed

publications and supplemented by the opinions o international experts.

Echinococcosis (hydatidosis): data are based on inormation obtained rom

peer-reviewed publications and the opinions o international experts.

Sources o inormation

Sources o inormation are as indicated in each diagram and specifc chapter.

All reasonable precautions have been taken to veriy and confrm the accuracy o the inormation contained in this publication.




REFERENCES

1. World population prospects: 2008 revision. New York, NY, United Nations PopulationDivision, 2009.

2. WHO preventive chemotherapy and transmission control databank. Geneva, World Health

Organization, 2010 (http://www.who.int/neglected_diseases/preventive_chemotherapy/

databank/en/index.html; accessed July 2010).

3. RabNet: human and animal rabies – an interactive and inormation mapping system [online

database]. Geneva, World Health Organization, 2010 (http://apps.who.int/globalatlas/

deault.asp).

who report on neglected tropical diseases

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