Gastrointestinal disease and disasters

Gastrointestinal disease 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

Learning Objectives

In the case of diarrhoeal disease,

understanding:

– The global incidence and prevalence

– Effects of poverty

– Vulnerability of children

– Effects of disasters

– Essential aspects of treatment

– Causes

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

– Control

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)

Diarrhoeal disease and

income

• GI diseases were the 2nd most

common causes of death in

low-income countries & the 6th

most common in lower-middle-

income countries in 2015

• GI diseases did not appear in

the top 10 causes of death in

upper-middle income and high

income countries in that year

(WHO data)

Children are

particularly

vulnerable

• Diarrhoeal disease and children <5Y – The second leading cause of death in children under five years old.

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

– Globally - nearly 1.7 billion cases of childhood diarrhoeal disease every

year

– A leading cause of malnutrition in children <5Y

• A significant proportion of diarrhoeal disease can be

prevented through safe drinking-water and adequate

sanitation and hygiene.[WHO Diarrhoeal Disease Fact Sheet May 2017]

Diarrhoeal disease and

disasters

• Disasters can lead to

increases in

incidence of

diarrhoeal disease

and increase the risk

of outbreaks.

Factors in disasters

potentially increasing risk

of GI disease

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

• Contamination of water supplies and food

• Breakdown of hygiene

• Breakdown of environmental health systems

• Displacement

• Overcrowding

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

Key measures to treat diarrhoea include the

following:• Rehydration:

– with oral rehydration salts (ORS) solution.

– with intravenous fluids in case of severe dehydration or shock.

• Zinc supplements:

– reduce the duration of a diarrhoea episode by 25% and are 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, and

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

months of life – to children when they are well

• Consult a health professional

– for management of persistent diarrhoea, when there is blood in stool or

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

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

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

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%

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

(rehydration project)

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.

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)

Useful

references

• The Mother and Child Health and Education Trust (rehydration project)Nand WadhwaniTST P O Box 95020, KowloonHong Kong nand@rehydrate.orgPhone: +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)

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

Other causes of GI disease

Viruses

• Rotavirus

• Adenovirus

• Astrovirus

• Norovirus

• Hepatitis A

Other

• Giardia

• Amoebiasis

• Cryptosporidiosis

• Toxoplasmosis

• Algal toxins

• Scombroid poisoning

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)

The big three bacterial GI

diseases• Cholera

• Dysentery

• Typhoid (Enteric

fever)

Others

• Less spectacular and may be endemic not

epidemic

• May cause more morbidity and mortality

but diagnostic confirmation can be difficult

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

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)

Cholera – situation in 2016(WHO data)

• 38 countries from all continents reported

132,121 cases & 2420 deaths (cfr 1.8%)

– 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

The situation in

Yemen• Civil war began in 2015

• >20 million people need humanitarian support

• 9.8 million in acute need of assistance

• Ca.17 million people (60 % of the population) are food insecure

• 7 million are at risk of famine

• Ca. 3 million have fled their homes

• Public services have broken down

• <50% of health centres functional

• No doctors left in 49/276 districts

• Access to safe water limited

Cholera in Yemen

• Cumulative totals 27/04/17-10/03/18– 1,076,472 suspected cases

– 2,265 associated deaths (CFR 0.21%)

– 1104 culture confirmed

– Attack rate: 385/10,000

– Sex ratio of cases: 1:1

– Median age of suspected cases: 20Y

– Median age of suspected cases dying is 38Y

• 59.2 % of deaths defined as severe cases at admission (Proportion of severe cases among suspected cases = 18%)

• Children < 5 Y : 28.8% of total suspected cases

Cholera in Yemen - Trends

• The weekly number of cases has been decreasing for 23 consecutive weeks

• The weekly proportion of severe cases has significantly decreased now representing 11% of admitted cases

• Week 07 (2018)– 3,362 suspected cases and 0

associated deaths were reported

– 11 % were severe cases

– 731 RDTs were performed, (151 +ve)

– (No culture tests performed)

(Data from Reliefweb)

Reservoirs & transmission

• Main reservoir is humans

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

• Can occur in copepods and other zooplankton

• Can persist in water for long periods and multiply in moist food

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)

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

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 and antibiotic sensitivity testing done no need to test all. Use case definition.

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

Treatment• Adequate rehydration

– Mild cases: ORS

– 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, shortens excretion of organism. (Ciprofloxacin, erythromycin are alternatives)

• 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.

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

Cholera: Specific prevention/control

measures

• Hospitalise severe cases with enteric

precautions (isolation not essential)

• Disinfect faeces and 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

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)

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%

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

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)

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

Enteric fever

• Typhoid fever: S.enterica enterica serovar Typhi

• Paratyphoid fever: S.enterica enterica serovar Paratyphi

• Classified on somatic O antigen, flagellar H and 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

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

• 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

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

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

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.

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

Enteric fever: the disease

• Weight loss and debilitating weakness

for months

• Relapses in 10%

• CFR:

– 10-20% untreated,

– <1% with prompt treatment

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

Differential diagnosis

• Malaria

• Dengue fever

• Lassa fever

• Brucellosis

• Leishmaniasis

• TB

• Influenza

• Tularaemia

• Amoebic abscess

Treatment

• Need to check on local antibiotic sensitivities (or

where the patient has been, for returned

travellers)

– Ciprofloxacin 250-500mg oral bd 7-14 days• Some resistance emerging in SE Asia, alternatives are co-trimoxazole or

ampicilllin

– Chloramphenicol - mainstay in much of world, 500 mg

qid oral/iv for 14 d

• Dexamethasone– steroids have been recommended for severe cases with shock

and reduced consciousness

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

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%

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

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

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

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

Control of GI diseasesHealth education messages

• In 1994. Ndosho Orphanage in Goma, Zaire.

• Children fleeing the Rwanda war

• Dysentery levels high despite conventional control

• Put dysentery education into the hands of the children. – Compose their own songs and mimed

how dysentery could be prevented.

– Held a Dysentery Song Contest - the children sang and danced and put over their health message.

– Songs were broadcast on a local radio station to the other camps

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