5.1. schisostomiasis

7/24/2019 5.1. Schisostomiasis

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SchistosomiasisBlood and Lymphatic

System


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Schistosomiasis (bilharziasis)

Schistosomiasis transmission hasbeen reported from 78 countries

(WHO, 2015).

In 2013 : > 40 million people, were

treated for schistosomiasis.

at least 90% of those requiringtreatment live in Africa.


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Schistosomiasis (bilharziasis)

>>> School-age children are often

most at risk tend to spend

time swimming or bathing in water

>>> in tropical and sub-tropical areas;

in poor communities with poor

sanitation, no adequate waterresources
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Species Geographic Distribution

S. japonicum Southeast Asia , Japan, parts of

China and Indonesia (Central of

Sulawesi).

S. mansoni Africa, Nile River valley in

Sudan and Egypt, SouthAmerica, Caribbean

S. mekongi Cambodia and LaosS. intercalatum Central and West Africa.

S. haematobium Africa, Middle East


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Species Intermediat

e host

Reservoir host

S. japonicum Onchomelania Various animals,

such as dogs, cats,

rodents, pigs, cow,horse and goats

S. mansoni Biomphalaria baboons

S. mekongi Neotriculaaperta.

dogs

S. intercalatum Bulinus


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Morphology

S.j. : : 26mm x 0.3 mm: 12-20 mm x 0.5 mm

Source: http://neglecteddiseases.wordpress.com/schistosomiasas/


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Eggs of Schistosoma

S. japonicum

S.mekongi

S.mansoni

S.intercalatum

S.haematobium

http://www.dpd.cdc.gov/dpdx/HTML/Frames/morphologytables/body_morph_figure6.htm


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Life Cycle


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Intermediate host

Source: http://www.infectionlandscapes.org/2012/06/schistosomiasis.html

Oncomelania snail

Biomphalaria snail

Bulinus snail


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Transmission:

contaminate freshwater sources with their

excreta containing parasite eggs which hatch

in water.

People become infected when larval forms of

the parasite (cercaria) penetrate the skin

during contact with infested water.


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Pathogenesis & Clinical Symptom

1. The incubation period usually 14-84 days;

Penetration of cercariae causes transient

dermatitis (swimmers itch)

Fever, chills,

urticaria, angio-neurotic edema cough, and muscle aches


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Pathogenesis & Clinical (contd)

2. Acute stage

Hyperemia in the wall of intestine (adult

worm arrive in the venules Trauma with hemorrhage ( eggs escape

from the venules intestinal mucosa

intestinal canal

Diarrhea and dysentry syndrome (severe

infection)


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Eggs secreted by adult worm pairs enter the

circulation and lodge in organs ( >>> liver)

immune responses to schistosome eggs

commonly lodge in the liver

granulomatous reactions cirrhosis of the

liver.


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3. Tissue proliferation &repair

The liver decreased in size : parenchyma

replaced by the scar tissue Splenomegaly

enlarged liver,

abdominal pain,

blood in the stool


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Portal hypertension

Cirrhosis ("Pipe stem Portal Fibrosis)

Ascites Central nervous system lesions have

been reported, but are rare.


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http://www.themonsterguide.com/MGWFSwimmersItch.html

Source:http://neglecteddiseases.wordpress.com

/schistosomiasas/


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Biopsy of liver,lung and colon


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Diagnosis

Microscopic:

Examination of stool for eggs

Serologic testing:for antischistosomal antibody


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Treatment

The goal :

reduction of worm load

reduction of egg production

reduces morbidity and mortality


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Treatment

Praziquantel(drug of choice)

Dose : 40 - 60 mg/kg per day orally

in 2 3 divided doses for one day


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Epidemiology & Control

The WHO strategy on use of anthelminthicdrugs now makes it possible to control

schistosomiasis in poor and marginalized

community Mass drugs administration / regular

treatment withpraziquantel (twice in a

year)

Eradication of snail with molluscacide

Health education is a must


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Epidemiology & control

In 2006, the prevalence of schistosomiasis

in Danau Lindu : 0.49% and 1.08% in

Napu Valley (1973: 73 %)


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Prevention

Avoid swimming or wading in freshwaterwhen you are in endemic areas

Drink safe water.

Vigorous towel drying after an accidental,very brief water exposure


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Thank you

5.1. schisostomiasis

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