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TRANSCRIPT
Common childhood infec-ons including vaccine-‐preventable diseases
Dr James Nu;all Paediatric Infec-ous Diseases Unit
Red Cross War Memorial Children’s Hospital & University of Cape Town
DCH 2016
Infec-ons in childhood
• Understanding & managing infec-ons/infec-ous diseases in an individual child but also in the family and wider community – Neonates to adolescents – May be a ‘normal’ part of childhood – Infec-ons have enormous impact on overall morbidity / mortality – Infec-ous diseases involve transmission from/to adults & other
children
• Provides insight into func-oning of health care system – Impacts all levels of care (primary / secondary / ter-ary) – Intersects with public health / epidemiology / laboratory – Preven-on (vaccina-on / prophylaxis / infec-on control interven-ons) – An-microbial therapy is one of most commonly prescribed treatments
in medicine (an-microbial stewardship)
• 5.9 million children <5yrs of age died in 2015 (16 000 each day) • Approximately 50% of deaths <5yrs of age are due to infec-ous diseases
How to approach this topic? • Infec-ons by organ system e.g. CNS: meningi-s, Renal: UTI etc
• Infec-ous (communicable) versus non-‐infec-ous infec-ons
• Vaccine-‐preventable diseases
• Common versus less common/rare
• Serious/invasive versus less serious infec-ons
• Bacterial, viral, fungal, protozoal…
Reading-‐1 • Child Health for All – a manual for Southern Africa, 5th edi7on (2012)
– Chapter 16 (page 128-‐139): Immunisa-on – Chapter 43 (page 369-‐382): Vaccine-‐preventable diseases
– Chapters 40 (HIV infec-on), 41 (Acute respiratory infec-ons), 42 (Diarrhoeal disease), 46 (Malaria), 47 (Tuberculosis), 50 (Parasi-c infec-ons of the gut)
• Coovadia’s Paediatrics and Child Health -‐ a manual for health professionals in developing countries, 7th edi7on (2014)
– Chapters 14-‐19, 22
• Handbook of Paediatrics, 7th edi7on (2010) – Chapter 9: Immuniza-on and infec-ons – Chapter 10: HIV infec-on – Other sec-ons relevant to ID (newborn, CNS, immunodeficiency)
• The two websites listed below include up-‐to-‐date disease fact sheets and vaccine informa-on for
vaccine-‐preventable diseases and other infec-ous diseases of childhood. Suggested minimum topics to cover include: all diseases on SA na-onal immunisa-on programme as well as rubella, chickenpox, influenza, rabies, typhoid, cholera, schistosomiasis, malaria & selected parasites.
– h;p://www.cdc.gov/ncidod/diseases/children/diseases.htm – h;p://www.who.int/topics/en/
Reading-‐2
• Ar7cles – Common Childhood Infec-ous Diseases_MIMS Handbook 2014
– Secondary & ter-ary preven-on of selected communicable diseases_MIMS Handbook 2014
– Immunisa-on: new vaccines, schedules, catch-‐up, contraindica-ons_MIMS Handbook 2014
Outline of seminar • Focus on “common” infec-ous diseases occurring during childhood – Viral exanthems – Non-‐viral exanthems – Other infec-ons targeted by vaccina-on programme
• Immunisa-on – Vaccines included in SA vaccina-on schedule – Other vaccines – Children with specific vaccina-on needs – Adverse events, contra-‐indica-ons, barriers
• Clinical approach to infec-ons/infec-ous diseases
Selected common infec-ons in childhood
• Viral exanthems – Measles – Rubella – Roseola infantum (Human Herpes Virus
6) – Erythema infec-osum (Parvovirus B19) – Enteroviral infec-ons – Hand-‐foot-‐mouth disease (Coxsackie) – Infec-ous mononucleosis (Epstein Barr
Virus) – Cytomegalovirus – Herpes simplex infec-ons – Varicella zoster (chickenpox / shingles)
• Non-‐viral exanthems – Scarlet fever (Grp A Strep) – Meningococcal disease – Tick bite fever – Staphylococcal infec-ons
– Kawasaki syndrome (uncertain ae-ology)
• Other infec-ons targeted by immunisa-on programme
– Polio – Diphtheria – Pertussis – Tetanus – Haemophilus influenzae type b – Streptococcus pneumoniae – Hepa--s B
Measles • Measles virus • Highly infec-ous pathogen, airborne transmission • Generally occurs in outbreaks / epidemics when vaccina-on
coverage drops (<90%) resul-ng in a suscep-ble popula-on • Constant surveillance & mass measles catch-‐up immunisa-on
campaigns required • Young infants (<9mths of age) at par-cularly high risk • Incuba-on period: 7-‐14 days • Prodrome: fever, cough, coryza may last from 3-‐7 days. Koplik spots
may be present from 2 days before un-l days aper onset of rash • Clinical features: fever, generalised erythematous maculopapular
rash starts on face/neck, progresses down body, conjunc-vi-s
Measles natural history “clinical -metable”
Measles • Diagnosis: clinical case defini-on, serology (measles IgM), PCR
tes-ng on blood or urine
• Treatment: Symptoma-c, Vitamin A, manage complica-ons
• Complica-ons: pneumonia, o--s media, laryngotracheobronchi-s, gastroenteri-s, eye involvement, encephali-s, malnutri-on
• Period of communicability: from 4 days before rash appears un-l 4 days aper onset of rash (if immunocompromised may be longer)
• Preven-on: vaccina-on, isola-on (airborne precau-ons) if available
Koplik’s spots
Rubella (German measles) • Rubella virus • Clinically milder disease than measles
– Rash less prominent, no conjunc-vi-s
• Complica-ons: arthri-s, encephali-s, thrombocytopaenia
• Congenital rubella syndrome: congenital cataracts or glaucoma, congenital heart disease, hearing impairment, purpura, hepatosplenomegaly, jaundice, microcephaly, developmental delay, meningo-‐encephali-s, radiolucent bone disease
Erythema infec-osum Parvovirus B19 (“slapped cheek syndrome”)
• Incuba-on period 4-‐21 days • Prodrome: fever, malaise, myalgia for 7-‐10 days • Clinical: “slapped-‐cheek” appearance to face, fine rash on trunk & limbs
• Diagnosis: clinical, serology, PCR
• Complica-ons: hydrops fetalis (intrauterine infec-on), aplas-c crisis (haemoglobinopathies, HIV), polyarthri-s
• Treatment: symptoma-c, blood transfusions, intravenous immunoglobulin
Infec-ous mononucleosis Ebstein Barr virus / “glandular fever”
• Incuba-on period: 30-‐50 days • Prodrome: fever, sore throat • Clinical: asymptoma-c, fa-gue, fever, pharyngi-s,
lymphadenopathy, generalised rash (exacerba-on with ampicillin or amoxicillin), splenomegaly. Symptoms may last wks-‐mths.
• Diagnosis: serology, PCR • Treatment: symptoma-c & suppor-ve
• Complica-ons: hepa--s, haemoly-c anaemia, thrombocytopaenia, meningo-‐encephali-s, transplant pa-ents (post-‐transplant lymphoprolifera-ve disorder, EBV-‐associated malignancies)
Cytomegalovirus • Cytomegalovirus (Human Herpes Virus 5) • Clinical:
– asymptoma-c or EBV-‐like illness, – intrauterine infec-on may result in severe mul-system involvement, neurodevelopmental problems, sensorineural hearing loss
– immunocomprised pa-ents (opportunis-c infec-on): pneumoni-s, re-ni-s, coli-s, disseminated infec-on
• Diagnosis: PCR • Treatment: an-viral therapy not usually required in
immunocompetent pa-ents, ganciclovir in immunocomprised / severe disease
Herpes simplex infec-on • Herpes simplex virus (1 & 2) • Prodrome: fever, irritability • Clinical:
– Primary infec-on: gingivostoma--s (painful oral ulcers), genital ulcers in sexually ac-ve, eczema herpe-cum (vesicular lesions in eczematous skin)
– Reac-va-on disease: herpes labialis (“fever blisters”) – Disseminated disease including encephali-s, hepa--s (mostly infants)
• Diagnosis: clinical, PCR • Treatment: symptoma-c, acyclovir, • Complica-ons: recurrent disease, disseminated disease
Varicella zoster infec-on • Varicella zoster virus • Incuba-on period: 14-‐21 days • Prodrome 0-‐2 days
• Clinical: – Primary infec-on (chickenpox): fever, vesicular rash (lesions at different stages of evolu-on) on trunk then limbs
– Reac-va-on disease (herpes zoster/shingles): vesicular rash in sensory nerve distribu-on (dermatome), pain/pruri-s
Varicella zoster infec-on • Diagnosis: clinical, PCR • Treatment: acyclovir for severe/immunocompromised cases,
analgesia
• Complica-ons: Primary infec-on: secondary bacterial skin infec-on, pneumonia, encephali-s; Reac-va-on disease: recurrences, disseminated infec-on (immunocompromised), post-‐herpe-c neuralgia
• Period of communicability: Chickenpox: 1-‐2 days before onset of rash un-l all lesions are crusted (usually 5-‐7 days aper onset of rash)
• Preven-on: vaccina-on (not currently in SA EPI schedule), isola-on with airborne transmission precau-ons in hospital
Herpes viruses
• Human herpes viruses 1-‐8 – Herpes simplex virus 1 (HSV-‐1) – Herpes simplex virus 2 (HSV-‐2) – Varicella zoster virus (VZV) – Cytomegalovirus (CMV) – Epstein-‐Barr virus (EBV) – Human herpes virus 6 (HHV-‐6) – Human herpes virus 7
– Human herpes virus 8 (KS)
Non-‐viral exanthems
Scarlet fever Group A streptococcal infec-on
• Incuba-on period: hours-‐days • Prodrome: fever, sore throat • Clinical: intense, erythematous rash on face & trunk,
circumoral pallor, strawberry tongue
• Diagnosis: clinical, evidence of streptococcal infec-on (ASOT/an--‐DNAse B), throat swab culture
• Treatment: penicillin
• Complica-ons: acute rheuma-c fever, myocardi-s, acute glomerulonephri-s, arthri-s
• Preven-on: appropriate an-bio-c treatment of pharyngi-s
Meningococcal disease • Neisseria meningi8dis • Clinical: fever, petechial or purpuric rash (may be preceded by maculopapular rash), sep-c shock
• Diagnosis: clinical, blood culture • Treatment: intravenous an-bio-cs (cephalosporin) and fluids, may need inotropic support
• Infec-on control: isola-on/droplet transmission precau-ons for 1st 48 hrs of an-bio-c treatment, telephonic no-fica-on & post-‐exposure prophylaxis to close contacts
• Preven-on: vaccina-on (not currently on SA EPI schedule)
Tick bite fever • Mainly due to African -ck bite fever (Ricke<sia africae) • Zoonosis (infec-on passed between animals & humans) • Vertebrate hosts: wild animals, ca;le, dogs, rodents • Main -ck vector: Amblyomma spp. • At risk individuals: farm workers, ecotourists
• Incuba-on period: 5-‐7 days • Prodrome: fever, headache, myalgia, malaise • Clinical: rash (50%), maculopapular, or vesicular, inocula-on eschar,
lymphadenopathy • Complica-ons: not common, haemorrhagic illness with mul--‐organ
involvement
• Treatment: an-bio-cs (doxycycline, fluoroquinolones in children <8 yrs) • Preven-on: protec-ve clothing, -ck repellents
Inocula-on eschar of Tick Bite Fever
Staphylococcal infec-on • Staphylococcus aureus • Clinical: wide spectrum of condi-ons – skin infec-ons
(impe-go, abscesses, scalded skin syndrome), invasive infec-ons (toxic shock syndrome, bacteraemia, pneumonia, ostei-s, endocardi-s)
• Diagnosis: clinical, culture • Treatment: an-bio-cs directed at S aureus, suppor-ve
treatment
• Complica-ons: invasive disease, mul--‐organ failure, an-bio-c resistance
Impe-go
Kawasaki syndrome • Acute, febrile, self-‐limi-ng, exanthematous, mul--‐system disease • Unknown ae-ology • 80% of cases under 5 years of age • 20% of untreated cases develop coronary artery aneurysms
• Clinical diagnosis, no confirmatory diagnos-c test • Fever persis-ng for at least 5 days + at least 4 of following 5 features:
– Changes in peripheries ( erythema and/or oedema of palms and soles; later desquama-on) or perineum
– Polymorphous exanthem – Bilateral conjunc-val injec-on – Changes on lips & oral cavity (red fissured lips, strawberry tongue, injec-on of oral/
pharyngeal mucosa) – Cervical lymphadenopathy
• In the presence of coronary artery involvement and fever, fewer than 4 of the remaining 5 criteria are sufficient
• Treatment: Intravenous immunoglobulin (IVIG) (2g/kg infused over 10-‐12 hrs) during first 10 days of illness reduces risk of aneurysms to <5%.
Poliomyeli-s • Majority of infected cases are asymptoma-c or have flu-‐like illness • May have biphasic illness: meningism followed by paralysis or “bulbar”
form of illness affec-ng circula-on & respira-on
• SA has been declared polio-‐free by WHO – Last cases in 1991 – Monitoring: acute flaccid paralysis (AFP) surveillance – Risk of impor-ng wild-‐type virus from neighbouring countries
• Recent outbreak in Namibia
• Vaccina-on – Oral polio vaccine at birth & 6 wks, inac-vated polio vaccine at 6/10/14 wks &
18 mths – Mass polio immunisa-on campaigns
• Eradica-on is technically feasible – No non-‐human reservoir, effec-ve vaccine incl. campaigns, AFP surveillance
Diphtheria • Corynebacterium diphtheria • Clinical:
– Severe upper airway obstruc-on due to pseudomembrane in oropharynx (“bull-‐neck”)
– Mycocardi-s in 1st or 2nd week of disease – Peripheral neuropathy / paralysis
• Effec-ve vaccine: rou-nely at 6/10/14 wks, 18 mths, 6 & 12 yrs • Disease surveillance & high vaccina-on coverage essen-al
– Recent outbreak in KZN (2015)
• Treatment: – An-bio-cs, diphtheria an--‐toxin, bed-‐rest, suppor-ve care, contact &
droplet transmission precau-ons, post-‐exposure prophylaxis for contacts
Pertussis (whooping cough) • Bordetella pertussis
• Clinical: cough paroxysms, apnoea (infants), seizures/encephalopathy, “100-‐day cough”
– Re-‐emergence of cases in adolescents/adults
• Difficul-es in accurate diagnosis – Clinical case defini-on – Microbiological confirma-on (PCR)
• Most deaths in infancy
• Transmission via respiratory droplets within 4 weeks of disease onset
• Vaccina-on: – Acellular vaccine safer than whole-‐cell vaccine, – Rou-ne schedule 6/10/14 wks, 18 mths – Adolescents/adults?
Tetanus • Clostridium tetani • Neonatal tetanus
– Contamina-on of umbilical stump – Exotoxin released by organism (tetanospasmin)
• Clinical: severe convulsions, recurrent muscle spasms, respiratory complica-ons frequent cause of death
• Treatment: debridement, an-toxin, an-bio-cs, suppor-ve care (ICU), rehabilita-on for survivors
• Maternal immunisa-on is key to preven-on • Neonatal tetanus elimina-on targets reached in SA in 2002 • Risk of breakthrough cases & tetanus in older child aper injury
Neonatal tetanus
Haemophilus influenzae type b • Severe respiratory infec-ons, meningi-s, epigloy-s, celluli-s, bone
& joint infec-ons • Treatment: ampicillin, suppor-ve care
• High case fatality rate (30%) & high incidence of neurological sequelae
• Rou-ne vaccina-on introduced in SA in 1999 – Conjugated vaccine, effec-ve in infants
• Hib disease now very uncommon
• Role of other serotypes & non-‐typeable H. influenzae
Streptococcus pneumoniae • 150 million global cases of pneumococcal disease annually, 1.6
million deaths • Very young & elderly, HIV-‐infected most at risk
• Clinical: meningi-s, pneumonia, bacteraemia, o--s media • Treatment: penicillin (resistance occurs and requires treatment
with cephalosporins)
• Preven-on: vaccina-on (& preven-on of HIV infec-on) – Polysaccharide vaccine not effec-ve <2 yrs of age – Conjugate vaccine (PCV 13) effec-ve at all ages, includes serotypes
associated with penicillin resistance – 6 & 14 wks, and 9 mths – Vaccine efficacy less in HIV-‐infected children
Hepa--s B • Children acquire Hep B via ver-cal transmission from mother (antenatally or
intrapartum) or via horizontal transmission during early childhood (mechanisms may include scarifica-on, ear-‐piercing, intra-‐familial spread, mosquito bites)
– Ver-cal transmission associated with higher chronic carrier rate
• Mostly asymptoma-c during childhood – Some children develop acute hepa--s which usually resolves without chronic carriage – Asymptoma-c carrier rates are around 2.5% <6 yrs of age, around 14% at 6-‐8 yrs of age
• Chronic carriage associated with development of cirrhosis and hepatocellular
carcinoma during adulthood (1 million global deaths annually)
• Preven-on: – rou-ne vaccina-on introduced in SA in 1995 for infants (6/10/14 wks), – birth vaccina-on? – Immunoglobulin to infant at birth in high risk pregnant women – occupa-onal risk includes healthcare workers
Immunisa-on
• “The two public health interven-ons that have had the greatest impact on the world’s health are clean water and vaccines.” World Health Organisa-on
• “The -me has come to close the book on infec-ous diseases. We have basically wiped out infec-on in the United States.” William Stewart, Surgeon General, USA, 1967
Some basic principles of vaccina-on
• Vaccines induce protec-on against a disease by s-mula-ng ac-ve immunity – Passive immunity may be provided by administra-on of immunoglobulin
• Comprise – sub-‐unit components or toxin of target pathogens, – inac-vated whole pathogens, or – live a;enuated organisms
• Polysaccharide an-gen may be conjugated with proteins to increase the immunogenicity (efficacy) of the vaccine par-cularly in infants
Live a;enuated & inac-vated vaccines
Vaccines included in SA schedule Extended Programme on Immunisa-on (EPI), WHO
South African schedule (2015) Extended Programme on Immunisa-on (EPI), WHO
SA rou-ne immunisa-on schedule by vaccine & age
Vaccine coverage • Cri-cal to maintain high levels of vaccine coverage for target diseases in order to achieve protec-on in a community – Infec-ousness of pathogen (e.g. measles >90% coverage required)
– Variable efficacy & -ming for different vaccines – Higher coverage obtained with vaccines given at earlier age (6/10/14 wks) than with vaccines given at 9 & 18 months (measles)
– Coverage figures vary depending on repor-ng agency – Herd immunity
Elimina-on & Eradica-on • Elimina-on (regional)
– Measles elimina-on defined as the absence of con-nuous disease transmission for 12 mths or more in a specific geographic area e.g. measles is no longer endemic in USA
– Highly effec-ve vaccine, strong vaccina-on programme with high vaccine coverage, well defined clinical presenta-on, no chronic carrier state, strong public health system for detec-ng & responding to measles cases & outbreaks, no reservoir (outside humans)
• Imported cases • Pockets of unvaccinated individuals
• Eradica-on (global) – Smallpox – Polio?
Barriers to achieving high vaccina-on coverage
• Limited integra-on of vaccina-on programme into all aspects of child health care delivery (separate ver-cal programme)
• Unavailability of vaccines (e.g. hospitals, stock-‐outs)
• An--‐vaccina-on lobby
• False contraindica-ons (parents & health care workers) – Family history of adverse reac-ons aper immunisa-on or convulsions – Previous mealses, mumps, rubella or pertussis-‐like illness – Preterm birth – Jaundice aper birth – Stable neurological condi-on (e.g. cerebral palsy, Trisomy 21) – Contact with an infec-ous disease or an-bio-c treatment – Underweight – Minor illnesses e.g. upper respiratory tract infec-on – Breas{eeding – Prematurity (use chronological age) – Non-‐specific allergies – Local reac-on aper previous DPT – Treatment with low-‐dose inhaled or topical cor-costeroids
Vaccines not currently included in SA EPI schedule
• Rubella – Live a;enuated virus – Measles mumps rubella (MMR) vaccine at 15 mths & 4-‐6 yrs + catch-‐up dose for girls prior to reproduc-ve age
– Aim is to reduce/eliminate congenital rubella syndrome (sensorineural hearing loss, congenital heart disease, cataracts/re-nopathy, developmental problems)
• Influenza – Annual recommenda-ons from WHO on strains included in vaccine
– Inac-vated virus – Recommended from 6-‐59 mths of age & in pregnancy – High risk groups (including health care workers) – Not shown to be effec-ve in HIV-‐infected children
Vaccines not currently included in SA EPI schedule
• Hepa--s A – 2 doses 6 months apart – Long las-ng protec-on (>10yrs) – Children & at-‐risk individuals (incl. health care workers)
• Varicella – Live a;enuated vaccine – Single dose from around 12 months of age – 2 doses more effec-ve (in adolescents & older individuals) – Contraindica-ons (pregnancy, immunosuppression) – Rela-vely low burden of severe illness in low resource countries so not regarded as high priority vaccine (WHO)
– Ins-tu-onal outbreaks
Vaccines not currently included in SA EPI schedule
• Meningococcal vaccines – Capsular & non-‐capsular vaccines – Capsular polysaccharide & polysaccharide-‐protein conjugate vaccines
– In SA, a capsular polysaccharide-‐protein conjugate vaccine (Menactra) is registered for use from 9 mths-‐55 yrs of age for preven-on of disease caused by A, C, Y, W serogroups of Neisseria meningi8dis
Children with special vaccina-on requirements
• HIV-‐infected children – Protec-ve an-body responses to Hib conjugate, Hep B, & pneumococcal vaccines are reduced but large burden of disease may s-ll be prevented
– Measles vaccine from 6 mths of age if admi;ed to hospital (followed by 9 & 18 mths)
• New measles vaccine will be given at 6 & 12 months to all children
– BCG is s-ll given at birth despite risk of disseminated BCG disease in HIV-‐infected infants
Children with special vaccina-on requirements
• Preterm babies – Should receive vaccina-ons according to chronological age (not
corrected gesta-onal age) if well and no contraindica-ons
• Children at special risk of infec-on – E.g. chronic lung, cardiac, renal, liver disease should receive annual
influenza vaccine & be considered for certain other vaccines e.g. Hep A, varicella
• Immunodeficiency (disease or treatment-‐related) – Live vaccines usually contraindicated, post-‐exposure prophylaxis with
immunoglobulins may be required
• Delayed or unknown immunisa-on status – ‘Catch-‐up’ schedules
Adverse events following immunisa-on
• Common minor adverse events
• Significant adverse events – No-fiable to local health authority
• Local – Severe local reac-on (swelling >5cm/>3 days), lymphadeni-s, injec-on
site abscess
• Systemic – Hospitalisa-on – Encephalopathy with 7 days – Collapse or shock-‐like state within 48 hrs – Fever >40.5°C within 48 hrs – Seizure within 3 days – Deaths (thought to be related to immunisa-on)
Contra-‐indica-ons to vaccina-on • Very few true contra-‐indica-ons, many ‘false’ contra-‐indica-ons – Severe allergic reac-on (anaphylaxis) to a vaccine component or following a prior to dose of a vaccine
– Encephalopathy occurring within 7 days of pertussis vaccina-on
– Severe systemic adverse reac-on to previous vaccina-on
– Egg allergy: avoid influenza & yellow fever vaccines, may receive measles vaccine
– Avoid live vaccines in severe immunosuppression & pregnancy
Clinical approach to a child who may have an infec-on/infec-ous disease
• History
• Examina-on
• Assessment
• Differen-al diagnosis
• Inves-ga-on plan – According to differen-al
diagnosis & severity of illness
• Treatment – Empirical if required – Directed
• Reassessments – Clinical – Laboratory
History
• Age of child
• Nutri-onal state
• Immunisa-on history
• Contact with other infected individuals
• Travel (prophylaxis)
• Symptoms – Prodromal symptoms
• Fever, lethargy, myalgia, upper respiratory tract
– Rash – Other localising symptoms
• Previous / current treatment
Infec-ous Diseases & The Road To Health Book
• Pregnancy & perinatal history – Exposure to ver-cally transmi;ed infec-ons
• E.g. syphilis, HIV, TB, others
• Vaccina-ons
• Exposure to horizontally transmi;ed infec-ons – E.g. TB & prophylaxis provided
• Feeding & growth
• Communica-on between levels of health care system – E.g. TB treatment, an-retroviral therapy
Examina-on
• General examina-on – Nutri-onal state – Fever – Cardinal signs including lymphadenopathy – Rash – Haemodynamic instability & shock
• Systems examina-on
• Pa;ern recogni-on / characteris-c features
• Specific complica-ons
Rashes in paediatric infec-ous diseases
• ‘Skin’ includes: – Body, hands & feet
(exanthem) – Nails – Scalp & hair – Mucous membranes – Mouth/nose/throat
(enanthem) – Eyes – Genital/perineal/perianal
• Descrip-ve terms include: – Erythematous maculo-‐
papular – Papular – Nodular – Vesicular – Ulcers – Petechiae – Vasculi-c (skin infarcts)
Pa;ern recogni-on & clinical case defini-ons
• Pa;ern recogni-on – Constella-ons of symptoms & signs e.g.
• headache / fever / vomi-ng: meningi-s, UTI • purpuric rash /shock: meningococcal disease
• “Alarm bells”
• Clinical case defini-ons e.g. – Measles
• Fever + rash + at least 1 of the 3 ‘C’s – Cough or coryza (runny nose) or conjunc-vi-s
• Useful in outbreaks for purpose of diagnosis, treatment (Vit A), surveillance
– Kawasaki syndrome
Assessment & differen-al diagnosis
• Assessment: iden-fica-on and statement of clinical diagnosis (based on history & examina-on) – e.g. lower respiratory tract infec-on ± specific complica-ons (e.g.
pleural effusion/empyema)
• Differen-al diagnosis & ae-ology – Viral (e.g. respiratory syncy-al virus) – Bacterial (e.g. Streptococcus pneumonia) – Mycobacterial (e.g. Mycobacterium tuberculosis) – Fungal (e.g. Pnemocys8s jirovecii) – Parasi-c (e.g. Plasmodium falciparum) – Combina-ons
Inves-ga-on plan
• According to priority of differen-al diagnosis – Consider severity of condi-ons & urgency of diagnosis regarding treatment (e.g.
meningi-s)
• Op-ons are: – Clinical diagnosis, no/minimal inves-ga-ons, no empirical an-microbial treatment
required (non-‐severe, self-‐limi-ng infec-on, symptoma-c treatment only) – Inves-ga-ons to screen for presence & site of infec-on, no empirical an-microbial
treatment (stable pa-ent) – Inves-ga-ons to screen for presence & site of infec-on & start empirical
an-microbial treatment (unstable pa-ent, poten-ally severe infec-on)
• Diagnos-c tests: will confirm/exclude diagnosis & determine ae-ology (e.g. lumbar puncture & cerebrospinal fluid evalua-on, measles serology)
• Non-‐specific tests for infec-on: including inflammatory markers (e.g. white cell count, C-‐reac-ve protein), imaging studies (e.g. CXR) & tests that assist in monitoring and managing the pa-ent (e.g. urea & electrolytes)
Infec-ous/communicable diseases A theore-cal framework
Exposure • Route of transmission: contact, droplet, airborne, vector • Risk factors for developing infec-on include dura-on & intensity of exposure,
infec-ousness of organism, suscep-bility of host í î Infec7on No infec7on ! Incuba7on period (disease-‐specific) ê • Clinical: prodromal / “seroconversion” illness or asymptoma-c/latent infec-on • Laboratory: specific immunological response (±isola-on of organism) í î Disease Infec7on only / no disease • Clinical diagnosis: pa;ern recogni-on / clinical case defini-on • Laboratory diagnosis: specific immunological response, isola-on of
organism/gene-c material (sensi-vity & specificity of tests)
Incuba-on period & prodromal period Incuba7on period Disease Prodromal period Short (1-‐7 days) Cholera Nil
Diphtheria Nil
Influenza Nil
Meningococcal disease Nil
Scarlet fever Nil
Intermediate (7-‐14 days) Measles 3-‐7 days
Pertussis Usually 5-‐7 days (up to 21 days)
Polio 3-‐36 days
Tetanus Nil
Typhoid Nil
Long (14-‐21 days) Chickenpox 0-‐2 days
Mumps 0-‐1 day
Rubella 0-‐2 days
15-‐40 days Hepa--s A 2-‐5 days
60-‐180 days Hepa--s B 2-‐5 days
Treatment principles
• Always try to obtain appropriate good-‐quality samples for microbiological inves-ga-ons prior to star-ng an-microbial treatment in order to facilitate microbiological confirma-on of a clinical diagnosis
– Helps to reduce prolonged courses of broad-‐spectrum an-microbials for unconfirmed diagnoses
– Allows one to obtain culture and drug sensi-vity results to guide op-mal drug choices
– Excep-ons include lack of access to relevant laboratory tests, contra-‐indica-on or inability to obtain appropriate samples (e.g. lumbar puncture) and urgency of ini-a-ng treatment prior to obtaining samples (e.g. meningococcal sep-caemia)
Treatment principles
• Empirical an-microbial treatment – Based on clinical diagnoses & severity of condi-on – Broad-‐spectrum agents (an-bio-cs, an-virals…)
• Directed an-microbial treatment – Confirmed diagnosis (or strongly suspected microbiologically) – Narrow-‐spectrum agents directed at specific organism/s
• Consider – Dosing & route of administra-on – Dura-on / adherence to treatment
• Infec-on preven-on & control – No-fica-on – Post-‐exposure prophylaxis for contacts – Transmission-‐based precau-ons in health care facility
Notifiable Medical Conditions
Acute flaccid paralysis Acute Rheumatic fever Anthrax Brucellosis Cholera Congenital syphilis Diphtheria Food poisoning (outbreak of >4 persons) Haemophilus influenza type B Haemorrhagic fever of Africa (Congo, Dengue, Lassa, Marburg & Rift Valley fever) Lead poisoning Legionellosis Leprosy Malaria Measles
Meningococcal infections Paratyphoid fever Plague Poisoning from any agricultural or stock remedy (e.g. pesticides/fertilizers) Poliomyelitis Rabies (specify whether human cases or human contact) Tetanus Tetanus neonatorum Trachoma Tuberculosis Typhoid fever Typhus fever (louse-borne) Typhus fever (ratflea-borne) Viral hepatitis (A, B, non-A non-B, undifferentiated) Whooping cough Yellow fever
Disease Who qualifies for post-‐exposure prophylaxis Recommended prophylaxis Chickenpox Non-‐immune contacts
Newborns whose mothers develop varicella from 5 days before to 2 days aper birth.
Varicella zoster immune globulin (VZIG) dosed according to manufacturer, administered within 96 hours of exposure OR Varicella vaccine within 72 hours of exposure. Vaccine is not indicated for newborns, children <9 months of age or HIV-‐infected children
Meningococcal disease
Household members and close contacts in day-‐care centres and hostels. Hospital contacts only if intense and in-mate contact e.g. resuscita-on / intuba-on
Cepriaxone: <12 years of age: 125mg, ≥12 years of age: 250mg as single intramuscular dose OR Ciprofloxacin: <12 years of age: 10mg/kg, ≥12 years of age: 500mg as single oral dose
Measles Suscep-ble children (received <2 measles vaccines) Human an--‐measles immunoglobulin (0.25ml/kg, and 0.5ml/kg for those who are immunocompromised, maximum dose 15ml, as single intramuscular dose) within 1 week of exposure
Hepa77s A Household contacts, children and staff in crèche or day-‐care seyngs or other ins-tu-onal seyngs, individuals at risk for severe disease e.g. underlying chronic liver disease
Pooled immunoglobulin dosed according to manufacturer OR Hepa--s A vaccine (for healthy individuals 1-‐40 years of age, who should also receive booster dose of vaccine 6 months later) within 14 days of exposure
Pertussis Household and other close contacts, vulnerable contacts at high risk of severe or complicated pertussis disease (including newborn infants born to symptoma-c mothers, infants <1 year of age with incomplete immunisa-on, immunocompromised, chronic cardiac or lung disease)
Erythromycin OR azithromycin OR clarithromycin. (Erythromycin is not recommended under 1 month of age). Chemoprophylaxis should start within 21 days of onset of cough in index case. Refer to guidelines [Ref 6] for dosing and dura-on.
Disease Period of communicability Measles 4 days before rash un-l 4 days aper onset of rash (immunocompromised pa-ents may be
contagious for dura-on of illness)
Rubella Approximately a week before onset of rash un-l 5-‐7 days aper onset of rash
Erythema infec-osum Approximately a week before onset of rash un-l appearance of the rash
Varicella zoster virus Primary infec-on: 1-‐2 days before rash un-l all lesions have crusted (usually 5-‐7 days aper onset of rash). Reac-va-on disease: onset of rash un-l all lesions have crusted
Meningococcal disease Un-l 2 days aper start of an-bio-c treatment
Scarlet fever Un-l rash fades & desquama-on starts
Viral gastroenteri-s Rotavirus is present in stools for several days before and several days aper onset of clinical disease
Hepa--s A Most infec-ous from 1-‐2 weeks before onset of jaundice un-l 1 week aper onset of jaundice.
Influenza From a few days before symptoms begin un-l 5-‐7 days aper onset of symptoms. Very young children and individuals with severe disease (e.g. viral pneumonia) may be infec-ous for >10 days aper onset of symptoms and severely immunocompromised individuals may shed virus for weeks to months.
Pertussis Most infec-ous during the catarrhal stage and for the first 2 weeks aper onset of cough. Other factors influencing communicability include age, immunisa-on status, and appropriate an-microbial therapy.
Mumps Un-l paro-d swelling subsides
Recommenda-ons on when children with selected infec-ous diseases are no longer regarded as infec-ous and may return to
school or other teaching ins-tu-on
Disease Isola7on Period Measles 5 days from start of rash Rubella 7 days from start of rash Chickenpox Un-l all skin lesions have crusted, usually 5-‐7 days aper start
of rash Meningococcal disease
2 days aper start of an-bio-c treatment
Scarlet fever Un-l rash fades and desquama-on starts Hepa--s A 7 days from onset of jaundice Pertussis 5 days from star-ng effec-ve an-bio-c therapy or 3 weeks
aper onset of paroxysmal cough Influenza Un-l apyrexial and feeling be;er or un-l 5-‐7 days aper onset
of symptoms
Infec-on Control Precau-ons for Health Care seyngs
• Standard precau-ons (“universal precau-ons”) – Hand disinfec-on – Gloves & mask when working with blood/body fluids – Safe disposal of sharps – Safe disposal of contaminated linen/other waste
• Transmission-‐based precau-ons – Contact – Droplet – Airborne
My 5 Moments for Hand Hygiene (WHO)
• Defines the key moments when health care workers should perform hand hygiene
• Evidence-‐based, field-‐tested, user-‐centred approach
Routes of transmission • Contact
– Direct (e.g. STI) – Indirect (e.g. faecal-‐oral)
• Droplet (e.g. influenza, streptococcus, pertussis, diphtheria) – Large droplets, contact with mucous membranes
• Airborne (e.g. TB, measles, varicella) – Small droplets, inhaled
• Vehicle / Vector – Biological (e.g. mosquito in malaria) – Mechanical
Contact precau-ons
• Organisms – Resistant bacteria
• Methicillin-‐resistant staphylococcus aureus (MRSA) • Extended spectrum B lactamase (ESBL)-‐producing Gram nega-ves • Carbapenem-‐resistant organisms e.g. Acinetobacter
– Clostridium difficile – Respiratory syncy-al virus – Adenovirus – Enteric illnesses (Hepa--s A, Salmonella, Shigella)
• Private room / cohort if possible • Limit movement around hospital • Use dedicated equipment (e.g. stethoscopes)
Droplet precau-ons • Organisms
– Meningococcus – Haemophilus influenzae B – Diphtheria – Pertussis – Adenovirus – Mumps – Influenza
• Separate cubicle if possible, or cohort, or ≥1 metre separa-on of beds
Airborne precau-ons
• Organisms – Tuberculosis – Varicella – Measles
• Private room with nega-ve pressure ven-la-on – 6 air changes per hour
• Gloves, gown & par-culate filter mask
An-microbial Stewardship
• A mul--‐disciplinary, systema-c approach to op-mising the appropriate use of an-bio-cs to improve pa-ent outcome and limit the emergence of resistant pathogens whilst ensuring pa-ent safety
• Other an-microbials