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Gastrointestinal diseases and disasters Dr Tim Healing Dip.Clin.Micro, DMCC, FZS, FRSB, CBIOL Course Director, Course in Conflict and Catastrophe Medicine Worshipful Society of Apothecaries of London Faculty of Conflict and Catastrophe Medicine

Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

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Page 1: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Gastrointestinal diseases and

disasters

Dr Tim HealingDip.Clin.Micro, DMCC, FZS, FRSB, CBIOL

Course Director,

Course in Conflict and Catastrophe Medicine

Worshipful Society of Apothecaries of London

Faculty of Conflict and Catastrophe Medicine

Page 2: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Learning Objectives

In the case of diarrhoeal disease,

understanding:

– The global incidence & prevalence

– Effects of poverty

– Vulnerability of children

– Effects of disasters

– Essential aspects of treatment

– Causes

• The “Big Three” (Cholera, Dysentery, Typhoid)

– Control

Page 3: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Diarrhoeal disease

globally• Deaths from diarrhoeal

diseases almost halved

between 2000 and 2015 ( )

due to improved sanitation,

treatment etc.

• Still caused 1.4 million

(2.5%) of the 56.4 million

deaths recorded in 2015

(WHO data)

Page 4: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Diarrhoeal disease and

income

• 2nd most common causes of

death in low-income countries &

6th most common in lower-

middle-income countries in

2015

• Did not appear in the top 10

causes of death in upper-middle

income & high income countries

in that year

(WHO data)

Page 5: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Children are

particularly

vulnerable

• Diarrhoeal disease & children <5Y – Globally - nearly 1.7 billion cases of childhood diarrhoeal disease every

year

– 2nd leading cause of death in children <5Y

– Each year diarrhoea kills around 525,000 children <5Y

– A leading cause of malnutrition in children <5Y

• A significant proportion can be prevented through safe

drinking-water & adequate sanitation & hygiene.

[WHO Diarrhoeal Disease Fact Sheet May 2017]

Page 6: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Diarrhoeal disease and

disasters

• Disasters can lead to

increases in

incidence of

diarrhoeal disease &

increase the risk of

outbreaks.

Page 7: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Factors in disasters

potentially increasing risk of

GI disease

• Breakdown of infrastructure (esp water purification systems and waste disposal)

• Contamination of water supplies & food

• Breakdown of hygiene

• Breakdown of environmental health systems

• Displacement

• Overcrowding

Page 8: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Dehydration

• The most severe threat posed by

diarrhoea is dehydration

• During a diarrhoeal episode, water &

electrolytes (Na+, Cl-, K+ and HCO3-) are

lost through liquid stools, vomit, sweat,

urine & breathing

• Dehydration occurs when these losses are

not replaced

Page 9: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Dehydration scale

• Severe dehydration (at least 2 of the following signs):

– lethargy/unconsciousness

– sunken eyes

– unable to drink or drink poorly

– skin pinch goes back very slowly ( ≥2 seconds )

• Some dehydration (2 or more of the following signs):

– restlessness, irritability

– sunken eyes

– drinks eagerly, thirsty

• No dehydration (not enough signs to classify as some or

severe dehydration)

Page 10: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Key things to do

1. Treat the patient (symptoms)

• Rehydration is key

2. Confirm diagnosis

• Epidemiological investigations

• Source

• Routes of transmission

• Demography of cases etc.

• Know if & when to use antimicrobials

• Know if & when to use other drugs (e.g.

antimotility drugs)

3. Control measures

Page 11: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Key measures to treat diarrhoea include the following:

• Rehydration:

– with ORS solution.

– with IV fluids in cases of severe dehydration or shock

• Zinc supplements:

– reduce the duration of a diarrhoea episode by 25%

– associated with a 30% reduction in stool volume in children (situation in

adults is not so clear)

• Nutrient-rich foods:

– give nutrient-rich foods – including breast milk – during an episode

– give a nutritious diet – including exclusive breastfeeding for the first 6

months of life – to children when they are well

• Consult a health professional

– for management of persistent diarrhoea

– when there is blood in stool

– if there are signs of dehydration. WHO Diarrhoeal Disease Fact Sheet May 2017

Page 12: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Rehydration

• The process of restoring lost water to the

body tissues and fluids.

• May need to replace electrolytes also

• IV (e.g. Ringers Lactate) • plain glucose solution is not suitable as it contains

no electrolytes

• ORS

Page 13: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

ORS• Must contain proper amounts of salt & sugar

– no salt > hyponatraemia

– salt absorption coupled with sugar absorption in the intestine

• Prepare solutions with clean water

• Appropriate drinks:– official ORSs

– salted rice water

– salted yogurt-based drinks,

– vegetable or chicken soup with salt

Homemade solution should have the "taste of tears.“

• Avoid drinks with a high concentration of sugar - can worsen diarrhoea– soft/sports drinks

– sweetened tea/ coffee

– medical tea infusions: high sugar content/caffeine > diuretic effects

Page 14: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Rehydration – reduced osmolarity

• Original ORS ineffective in reducing

diarrhoea compared to other solutions,

including rice water

• 2003, WHO/UNICEF introduced reduced

osmolarity ORS

– decreases stool output, by about 25%,

– reduces vomiting by nearly 30%

Page 15: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Home-made ORS[The Mother and Child Health and Education Trust]

(rehydration project)

Page 16: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Zinc• In diarrhoea & cholera, zinc deficiency

causes reduced water & electrolyte absorption

• In trials, children with diarrhoea receiving zinc:– recovered faster

– had increased strength & appetites

– were less ill than children not on zinc

• 10 - 14-day treatment with zinc reduces duration & severity of persistent & acute diarrhoea.– 25% reduction in duration of acute diarrhoea

– 40% reduction in treatment failure and death in persistent diarrhoea.

– Also leads to• Increased ORS uptake

• Reductions in inappropriate drug use (antibiotics & anti-diarrhoeal medications)

Qadir MI, Arshad A, Ahmad B.

Zinc: Role in the management

of diarrhea and cholera. World

Journal of Clinical Cases :

WJCC. 2013;1(4):140-142.

doi:10.12998/wjcc.v1.i4.140.

Page 17: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

WHO-UNICEF recommended policies for health

professionals on treatment of diarrhoea (including cholera)

in children

• Give suitable home fluids immediately child gets diarrhoea

• Treat dehydration with low osmolarity ORS solution (or IV electrolyte solution for severe dehydration)

• Advise mother to:– Continue feeding or increase breast feeding during diarrhoea

– Increase feeding after diarrhoea

• Use antibiotics only when appropriate (i.e. bloody diarrhoea/shigellosis).

• Do not give anti-diarrhoeal drugs

• Give children 20 mg/day zinc supplement for 10-14 days (10 mg/day for infants <6 months)

Page 18: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Useful

references

• The Mother and Child Health and Education Trust (rehydration project)Nand WadhwaniTST P O Box 95020, KowloonHong Kong [email protected]: +852 3482 5121Fax: +1 913 273-8778

• Diarrhoea: Why Children are still dying and what can be done(UNICEF/WHO 2009)

• Clinical Management of Acute Diarrhoea (WHO/UNICEF, 2004)

Page 19: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Principal bacterial causes of GI disease

• Salmonellas– S.enterica

• 2,500 serotypes

• S.enterica enterica serovar Typhi

• S.enterica enterica serovar Paratyphi

– S.bongori

• Campylobacter– C.jejuni

– C.coli

• E.coli– Enterohaemorrhagic

– Enterotoxigenic

– Enteroinvasive

– Enteropathogenic

– Enteroaggregative

– Diffuse-adherence

• Shigella– S.dysenteriae

– S.flexneri

– S.boydii

– S.sonnei

• Vibrio– V.cholerae

– V.parahaemolyticus

– V.vulnificus

• Bacillus cereus

• Clostridium perfringens

• S.aureus

• Yersinia

• Listeria

Page 20: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Other causes of GI disease

Viruses

• Rotavirus (common cause in

children)

• Adenovirus

• Astrovirus

• Norovirus (common cause in

children and most common cause in

adults)

• Hepatitis A

Other

• Giardia

• Amoebiasis

• Cryptosporidiosis

• Toxoplasmosis

• Algal toxins

• Scombroid poisoning

Page 21: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Rotaviruses

• A very important cause of morbidity

& mortality in children

• WHO estimates that globally 215,000 child

deaths occurred in 2013 due to rotavirus

infection

– 37% of the 578,000 diarrhoeal deaths in children

– 3.4% of all child deaths

• This compares to 528,000 in 2000

• Decline due to:

– improved hygiene and sanitation

– Rotavirus vaccine

Tate JE, Burton AH, Boschi-Pinto C, Parashar

UD. Global, Regional, and National

Estimates of Rotavirus Mortality in Children

<5 Years of Age. Clinical Infectious Diseases

2016:62 (Suppl 2) S105

Page 22: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Norovirus (winter vomiting bug)

• Most common cause of

gastroenteritis

• Ca. 685 million cases &

200,000 deaths annually

• Children <5Y particularly

infected - ca. 50,000 deaths

occur in this group

Page 23: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Don’t forget!

Diarrhoea +/- vomiting

+/- fever may be a

symptom of another

type of disease –

not a GI infection

CDC Atlanta:

Symptoms of Ebola include:

• Fever

• Severe headache

• Muscle pain

• Weakness

• Fatigue

• Diarrhea

• Vomiting

• Abdominal (stomach) pain

• Unexplained hemorrhage

(bleeding or bruising)

Page 24: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

The big three bacterial GI

diseases• Cholera

• Dysentery

• Typhoid (Enteric

fever)

Page 25: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Others

• Less spectacular and may be endemic not

epidemic

• May cause more morbidity and mortality

but diagnostic confirmation can be difficult

Page 26: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Cholera: the blue death

Page 27: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Cholera

• Vibrio cholerae– More than 200 serogroups

– Only two (O1 and O139) cause severe disease and epidemics

• O1 has two biotypes– Classical

– El Tor

• Each of these biotypes occurs as three serotypes:– Inaba

– Ogawa

– Hikojima (rare)

• Current (7th) pandemic due to O1 El Tor

Page 28: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Cholera• Asian in origin (Gulf of Bengal)

• First western awareness 1817

• 6 pandemics in 19th Century

• Mainly in Asia in 1st half of 20th

Century

• 2nd half of 20th Century– 7th pandemic (V. cholerae O1 El

Tor) spread from Indonesia

– Explosive epidemics of non-O1 V.cholerae (O139 Bengal –emerged 1992 – currently confined to SE Asia)

– Recognition of environmental reservoirs (Gulf of Bengal, US coast of Gulf of Mexico)

Page 29: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Cholera – situation in 2017(WHO data)

• 34 countries from all continents reported 1,227,391

cases & 5654 deaths (cfr 0.5%)

– 54% of cases from Africa

• Five countries accounted for 80% of all cases– Democratic Republic of the Congo (DRC)

– Haiti

– Somalia

– United Republic of Tanzania

– Yemen

• Globally, the true number of cases is estimated to be

much higher

– estimated 1.4 to 4.0 million cases & 21,000 -143,000

deaths/yearWHO Weekly Epidemiological Record. No.36 ,2017, 92

Page 30: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

The situation in

Yemen

• Civil war began 2015

• Public services have broken

down

• <50% of health centres

functional

• No doctors left in 49/276

districts

• Access to safe water limited

Page 31: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Cholera in Yemen

• Jan 2018 - April 2019

– 649,910 cases

– 1,066 deaths (CFR 0.16%)

• Epidemiological week 17

(21 – 28 April) of 2019

– 22,502 suspected cases of

cholera (18% severe)

– 25 associated deaths

– 22.6% of suspected cases

are children <5Y

Page 32: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Reservoirs & transmission• Main reservoir is humans

• Transmitted by ingestion of contaminated water, ice, shellfish, food (usually due to water contamination)

• Direct person to person spread appears to be rare

• Can occur in copepods & other zooplankton where it can multiply

• Can persist in water for long periods & can potentially multiply in moist food

Page 33: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Cholera: pathogenesis

• Cholera exerts its pathogenic effects by means of a toxin

• The toxin (a protein) causes the secretion of water, Na+,

K+ & HCO3- into the lumen of the small intestine

– This flushes the rapidly multiplying V.cholerae bateria out into

the environment

– Leads to rapid dehydration of the patient

• Cholera organisms are readily destroyed by gastric

acids.

– Infectious dose is high (108 - 1011 cells)

Page 34: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Cholera: the disease

• Majority of cases asymptomatic or mild (esp El Tor) - but can transmit infection

• Acute disease

– Sudden onset

– Nausea & profuse vomiting in early stages

– Profuse, painless, watery diarrhoea

– Rapid dehydration, acidosis, circulatory collapse, hypoglycaemia (in children)

– CFR can be >50% untreated (<1% if treated)

Page 35: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

WHO proposed clinical case definitions

• Disease unknown in area: severe dehydration or

death from acute watery diarrhoea in a patient aged

5Y or more

• Endemic cholera: acute watery diarrhoea with or

without vomiting in a patient aged 5Y or more

• Epidemic cholera: acute watery diarrhoea with or

without vomiting in any patient

Page 36: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Diagnosis - Lab confirmationCary Blair transport medium – faecal sample

or rectal swab

– Presumptive diagnosis by microscopy

– Isolation

– Serogrouping (O1,O139), serotyping of O1

– Tests for • cholera toxin gene

• antibiotic sensitivity

– RDTs

• Epidemics – once lab confirmation & antibiotic sensitivity testing done no need to test all. Use case definition.

• Monitoring an epidemic - include regular lab confirmation & antibiotic sensitivity testing

Page 37: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Treatment• Adequate rehydration

– Mild cases: ORS (ca. 80% of cases)

– Severe cases: IV (initially 30ml/kg/hr for infants <1Y,

>1Y 30ml/kg/30 mins then reassess)• Ringers Lactate is best (or Dacca solution)

• Normal saline can be used if Ringer's lactate solution is unavailable.

• Plain glucose solutions ineffective

– Give ORS to cholera patients on IV as soon as they can drink, even before IV therapy has been completed

– Then treat with ORS until diarrhoea stops

• Antibiotics (severe cases)

– Adults 300mg doxycycline or 500mg tetracycline q.d.s / 3 days.

– Children 12.5 mg tetracycline q.d.s for 3 days – shortens diarrhoea, & excretion of organism. (Ciprofloxacin, erythromycin are alternatives)

– (NB. Widespread resistance to tetracycline, trimethoprim-sulfamethoxazole, & erythromycin)

• Zinc– 10-20mg zinc supplement/day reduces duration & severity of diarrhoea

in children with choleraRoy SK, et al. Zinc supplementation in children with cholera in

Bangladesh: randomized controlled trial. BMJ. 2008;336(7638):266-71.

Page 38: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Disaster implications

• High risk in endemic areas

• Must inform WHO

• IHR 2005• Deal with transport from cholera areas as specified

in IHR

• No country allowed to require proof of cholera vaccination as entry requirement

• Immunisation recommended for travellers with known risk factors:

– hypochlorhydria

– cardiac disease

– the elderly

– blood group O

Page 39: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Cholera: Specific prevention/control

measures

• Hospitalise severe cases with enteric

precautions (isolation not essential)

• Disinfect faeces & vomit with heat, phenol,

chlorine

• Quarantine not applicable

• Manage contacts (chemoprophylaxis rarely

advisable)

• Vaccines

– Traditional killed whole cell vaccines of little use

– WHO pre-qualified oral cholera vaccines (OCVs):

Dukoral®, Shanchol™, & Euvichol®. All 3 require

2 doses for full protection

• Induce antibodies that:

– prevent bacterial attachment to the intestinal

wall

– binding of toxin to the intestinal mucosa

Page 40: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

WHO Position Paper on Vaccines against Cholera

(August 2017)

• States that:

– OCV should be used in areas with endemic cholera,

in humanitarian crises with high risk of cholera, and

during cholera outbreaks; always in conjunction with

other cholera prevention and control strategies

– vaccination should not disrupt the provision of other

high priority health interventions to control or prevent

cholera outbreaks

Page 41: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Shigellas

Gm –ve rods (closely related to E.coli & Salmonella)

Four serogroups:

• Serogroup A: S,dysenteriae (12 serotypes)

• Serogroup B: S.flexneri (6 serotypes)

• Serogroup C: S.boydii (23 serotypes)

• Serogroup D: S.sonnei (1 serotype)

Three Shigella groups are the major cause of disease:

S. dysenteriae dysentery epidemics, particularly in confined populations

(e.g. refugee camps)

S. flexneri 60% of sporadic cases in the developing world

S. sonnei 77% of cases in the developed world (15% of cases in the

developing world)

Page 42: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Shigellosis• Acute disease of distal small intestine & colon

– Loose stools (small volume) containing blood & mucus (NB. Watery diarrhoea can occur)

– Fever

– Nausea

– Vomiting• Toxaemia

• Cramps

• Tenesmus

• Complications include:– Convulsions (young children)

– Toxic megacolon

– Intestinal perforation

– Haemolytic Uraemic Syndrome

• CFR can be >20%

Page 43: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Pathogenesis

• Shigellas attack the large intestine by:

– direct invasion of epithelial cells in the large intestine

– production of two enterotoxins

• Shigella is not destroyed by gastric acid

– As a result, it takes only 10 to 200 cells to cause an

infection

– This infectious dose is several orders of magnitude

smaller than that of other species of bacteria

(e.g. Cholera has an infectious dose between 108 -

1011 cells)

Page 44: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Shigellosis

• Ca 125 million cases and 14,000 deaths

worldwide/year*

• 66% of cases & most deaths in children <10Y*

• 2o attack rates in households can be ca 40%

• Transmitted by faecal-oral route

– Directly (person to person)

– Indirectly (food & water, flies)

• Infective dose small (10-100 organisms)

• Cases infectious up to 1/12 after illness

*Heymann D (Ed). Control of Communicable Diseases

Manual, 20th Edition, 2015

Page 45: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Treatment

• Fluid & electrolyte replacement (if watery

diarrhoea or signs of dehydration)

• Antibiotics

– depending on local sensitivity patterns – can shorten

duration and severity of illness

• Fluoroquinolones (ceftriazone, azithromycin)

• High levels of resistance to ampicillin, co-trimoxazole,

tetracyclines

• Loperamide/antimotility drugs contraindicated

(especially in children) (can prolong illness)

Page 46: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Shigella control

• Nurse with enteric precautions

• Infected persons should not:– prepare food,

– provide child or patient care until 2 successive faecal samples/rectal swabs collected >24hrs apart and

48hrs after ending of antibiotic treatment are –ve

• Report to Health Authorities

• Investigate sources

• Contact tracing

• Prophylactic antibiotics not recommended

• No vaccine for bacillary dysentery

Page 47: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Enteric fever

• Typhoid fever: S.enterica enterica serovar Typhi

• Paratyphoid fever: S.enterica enterica serovar Paratyphi

• Classified on somatic O antigen, flagellar H & surface virulence V1 antigens

• Ingestion of 1.0 x 106 S. e. e. Typhi bacilli caused disease in 50% of healthy unvaccinated men

• 200 orgs may cause disease

• Paratyphoid is less virulent

Page 48: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Occurrence

• Worldwide especially in developing world, – Ca 22 x 106 cases & 200,000 deaths annually

• Industrialised world– mostly in travellers to endemic areas

• Common in disasters and anywhere there is a breakdown of sanitation

• Paratyphoid sporadic, less serious, serotype A most common

Page 49: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

• Via food and water contaminated by faeces and urine of cases or chronic carriers (Typhoid Mary)

• Important vehicles include:– Sewage contaminated shell-fish

– Raw fruit & vegetables fertilised with night soil

– Milk & milk products contaminated by handlers

– (Faulty canned meat)

Transmission

Photo: Tim Healing

Page 50: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Reservoir

• Humans. – Carrier state can follow illness independent

of severity

– Short-term faecal carriers (urine carriers rare)

– Chronic carrier state most common (2-5%) in middle aged

– Chronic carriers often have biliary tract abnormalities including gallstones (carriage in gall bladder)

• Communicability– Whilst feces remain +ve

• Up to 3/12 in 10% of cases

• Permanently in 2-5% of cases

Page 51: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Enteric fever: the disease• Varies from mild disease with low grade fever to severe disease with

multiple complications

• Severity influenced by:– strain virulence

– size of inoculating dose

– age of patient

– vaccination history

– duration of illness before treatment

• Mild disease is like gastroenteritis

• Severe disease has insidious onset– Sustained fever

– Severe headache

– Malaise

– Anorexia

– Relative bradycardia

– Splenomegaly

– Non-productive cough

– Abdominal pain in 20-40% of cases

– Constipation

Page 52: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Rose spots

• Rose spots on trunk in

25% of cases - end of

first week.

• Salmon colour maculo-

papular, 1-4 cm,

blanching, resolve in 1-

5 days

• Difficult to see in

patients with dark skin.

Page 53: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Enteric fever:

the disease

• Week 2• fever

• abdominal distension

• splenomegaly

• Week 3• thready pulse

• weight loss

• lung base crepitus

• apathy/confusion

• some pea-soup diarrhoea

• Week 4• slow improvement of mental

state, apathy, abdominal

distension

• intermittent intestinal

symptoms

Page 54: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Enteric fever: the disease

• Weight loss & debilitating weakness for

months

• Relapses in 10%

• CFR:

– 10-20% untreated,

– <1% with prompt treatment

Page 55: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Diagnosis

• Isolate organism:– from blood cultures (early in disease)

– from faeces and urine (after 1st week)

• Culture from bone marrow most sensitive & useful even if patients have had antibiotics

• New rapid sero-diagnostic tests show promise

• ELISA IGM for V1 antigen good serological test

• Widal serological test obsolete

Page 56: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Differential diagnosis

• Malaria

• Dengue fever

• Lassa fever

• Brucellosis

• Leishmaniasis

• TB

• Influenza

• Tularaemia

• Amoebic abscess

Page 57: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Treatment• Check on local antibiotic sensitivities (or where the patient

has been, for returned travellers)

– Resistance to ampicillin, chloramphenicol, trimethoprim-

sulfamethoxazole & streptomycin now common

– Ciprofloxacin 250-500mg oral bd 7-14 days

• Some resistance emerging in SE Asia,

– Ceftriaxone (1-2 g/day) or azithromycin (10 mg/kg) are alternatives

– Chloramphenicol - mainstay in much of world, 500 mg qid oral/iv

for 14d

• [Dexamethasone?– steroids have been recommended for severe cases with shock & reduced

consciousness

– based mainly on a single study in 1986 (Jakarta study)

– use with care, especially where HIV/AIDS is present]

Hoffman SL, Punjabi NH, Kumala

S, et al. Reduction of mortality in

chloramphenicol-treated severe

typhoid fever by high dose

dexamethasone. N Engl J

Med 1984:310: 82-8

Page 58: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Specific Control Measures

• Exclude carriers from food handling or patient contact

– Treat carriers 750mg cipro bd / 28d

• Capsular V1 polysaccharide vaccine every 3 years IM protects around 70%

Page 59: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Disaster Implications

• Report to local health authorities

• Water, sewage and food hygiene measures

• Search for carrier if point source outbreak

• Selectively immunise if feasible - stable population etc, but basic control measures more important

• Immunise travellers to endemic & epidemic areas

Page 60: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

General measures to control GI diseases

• Identify

• Treat cases

• Find carriers/contacts (treat if appropriate)

• Inform authorities

• Break chain of infection

– Clean water/safe food

– Improved sanitation

– Hygiene/handwashing

– Public health education

– Waste disposal/pest control

– Exclusive breastfeeding for the first 6 months of life

• Rotavirus vaccination

Page 61: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Control of GI diseases

• Clean water– Decontaminate (filter, chlorinate etc).

– No faecal coliforms/100ml at point of delivery

– Take steps to minimise post-delivery contamination

• Safe food

– Stored carefully

– Prepared and served hygienically

– Education of food handlers

– Proper waste disposal

Page 62: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Control of GI diseases

• Waste disposal

– Burial

– Incineration– Fuel

– Pollution

– Recycling

• Pest control• Control breeding sites

• Use of pesticides

• Good hygiene &

sanitation practice

• Waste control

Page 63: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Control of GI diseases

• Hygiene– Hand washing

• after using the toilet,

• before and after handling infants

• before preparing or serving food

• before eating

Is one of the most important public health measures that can be employed

– Hand washing facilities must be available at toilets, & at food preparation areas & outlets

– Proper flyproof toilet facilities

– Regular cleaning of toilet and other hygiene facilities

Page 64: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Hygiene promotion

• Public education is a

vital part of any

disease control

programme

• Messages & methods

of delivery must be

culturally appropriate

• Consult the

community affected –

not just the authorities Photos: Julienne Anoko

Page 65: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Ndosho Children’s Centre

• Ndosho Centre for Unaccompanied Children in Goma, Zaire, opened 1993

• Built for 40 children

• In July 1994 ca. 1 million Rwandans fled into Goma

• By end July 1994, Ndosho held 2500 children

Page 66: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Medical Care

• MERLIN asked to provide medical care

• Other NGOs dealt with, nutrition, water, shelter

etc.

• Encadreur system introduced to support

children

– Older children supervise groups of younger children

– Assisted with daily living

– Helped ensure services functioned

Page 67: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Outbreak of dysentery

• Bacillary dysentery (due to Shigella sonnei) broke out in August 1994

• Conditions ideal for spread

– Children crowded in tents

– Enough clean water available but access poor for <5Y & the sick

– Too few latrines & environment soiled with faeces

– Children shared eating & drinking utensils

– Children susceptible to infection due to malnutrition related immunosuppression

Page 68: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Diarrhoeal illness at Ndosho.

Treatment policy:

• Patients with bloody diarrhoea received ciprofloxacin & rehydration

• Patients isolated

• Health education programme started

• This was not successful– Numbers of cases

increased

– Large outbreak of non-bloody diarrhoea

Page 69: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

Dysentery song contest

• Children liked to dance & sing - encouraged to take active role

• Encadreurs were taught about how dysentery is spread, treated, prevented

• Produced rhyme with this, & then, with children, a song & dance/mime

• Concert held one week later. Costumes, drums. Prizes given.

• Songs broadcast over UNHCR radio to other camps

• Health message put over in culturally acceptable way

Dr Paul Eunson and children

dancing during the contest at

Ndosho

Page 70: Gastrointestinal disease and disasters · –The global incidence & prevalence –Effects of poverty –Vulnerability of children ... –Enterohaemorrhagic –Enterotoxigenic

After the contest!

• One week after this diarrhoea numbers fell

• There was no further outbreak

• (Not a controlled study but still >1000 children at Ndoshowho had not had diarrhoea)

Contest