Diarrheal Diseases

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Diarrheal Diseases
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Leading Causes of Childhood Deaths
Source WHO estimates of the causes of death in
children, 2000-03 Bryce, Lancet, 26 March 2005
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Major Causes of Death in emergencies for lt5 Years
Sudan Wad Kowli Camp February, 1985
Somalia Gedo Region 7 Camps, January, 1980
Measles ARI Malaria Diarrhea Other
Source Centers for Disease Control and
Prevention, Famine-Affected, Refugee, and
Displaced Populations Recommendations for Public
Health Issues. MMWR, 199241(No. RR-13)8.
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Objectives

• The organisms
• Clinical features
• Diagnosis
• Treatment
• Epidemiology
• Preparedness

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Diarrheal Diseases

• Viruses
• Rotavirus
• Norovirus

• Bacteria
• E. coli
• Shigella
• Salmonella
• Campylobacter
• Yersinia
• Cholera

• Parasites
• Giardia
• Cryptosporidia
• Entamoeba histiolytica

Common Causes of epidemic diarrhea
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• Shigella - Microbiology

• Aerobic, non-motile, Gram negative bacilli
• Four subgroups (many serotypes)
• Shigella dysenteriae (group A)
• Shigella flexneri (group B)
• Shigella boydi (group C)
• Shigella sonnei (group D)
• Only reservoir people (and other primates)
• Shigella Dysenteriae serotype 1 greatest concern

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Shigella dysenteriae type 1(Shiga bacillus)

• Most virulent of four serogroups of Shigella
• Cause of epidemic dysentery
• Bloody diarrhea
• Abdominal cramps
• Fever
• Rectal pain

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Shigella dysenteriae type 1

• Infectious dose low (10-100 organisms)
• Disease more severe in elderly, infants,
  malnourished
• Complications
• Hemolytic-uremic syndrome (HUS)
• Seizures
• Sepsis
• Death rates 1-10

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Shigella dysenteriae type 1

• Diagnosis
• Blood is observed in a fresh stool specimen
• Stool culture
• Organisms die quickly
• Transport in special culture media
• Transport cold
• Reference laboratories
• Resistance testing

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Treatment in resource poor settings

• Zinc
• Rehydration
• Antimicrobial Agents
• Fluoroquinolones limited evidence for short
  course (1-2 doses) in children and adults
• If susceptible naladixic acid, chloramphenicol,
  tetracycline
• Less available and more expensive
  pivamdinocillin, ceftriaxone, azithromycin

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Shigella dysenteriae type 1

• Treatment
• Mainstay of therapy is antimicrobials
• Monitoring for antimicrobial resistance crucial
• Resistant to a wide variety of antimicrobials in
  many parts of the world
• Resistance to antimicrobials acquired rapidly
• WHO now recommends ciprofloxacin as first-line
  empiric therapy

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Shigella dysenteriae type 1

• During epidemics gt33 of population can be
  infected
• Conditions that facilitate epidemics
• Poor sanitation
• Substandard hygiene
• Inadequate water supplies
• Epidemics often occur during hot, humid, rainy
  seasons

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Shigella dysenteriae type 1Transmission

• Thought to be
• Person-to-person
• Contaminated food
• Water
• Contact with objects contaminated with the
  organism (fomites)
• Sharing latrines

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Prevention of Shigella dysenteriae infections

• Handwashing with soap
• Breast-feeding
• Food safety
• Safe water
• Clean water supply
• Home storage and treatment
• No vaccines available!

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Three Simple Rules for the Prevention of Dysentery

• Cook your food
• Boil your water
• Wash your hands
• (Make sure your neighbors wash their hands)

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Preparation for Shigella dysenteriae type 1
Epidemics

• Surveillance and reporting
• Laboratory
• Treatment policy
• Emergency stocks of essential supplies
• Training in case management
• Community education about importance of
  antimicrobials in diarrhea

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Surveillance and Reporting

• Case definition
• Diarrhea with visible blood
• Laboratory confirmation of first cases!
• Maintain case records
• Allows accurate reporting and assists with
  maintenance of adequate supplies
• Surveillance for antimicrobial resistance!
• Must continue to collect stools

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When Should an Outbreak of Dysentery Be Suspected?

• Sudden increase in daily or weekly numbers of
  patients with bloody diarrhea
• Increase in proportion of all cases that are
  bloody
• Increase in deaths from bloody diarrhea

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Questions about dysentery?
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Vibrio cholerae
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Vibrio Cholerae
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Vibrio cholerae O1

• Salt resistant
• Heat and acid sensitive
• El Tor biotype
• Asymptomatic infections common
• 75 asymptomatic
• 18 mild diarrhea
• 1-5 severe-cholera gravis
• Fast growing in food
• Lengthy survival in environment

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Vibrio cholerae O1

• Infectious dose 106 108
• Varies with vehicle of transmission
• Gastric acidity
• Incubation period
• 1-3 days (½-5 days)

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Transmission-worldwide

• Contaminated water
• Contaminated food
• Raw or undercooked seafood
• Rice, cereals, gruels left at ambient temperature
• Person to person transmission not common
• Fecal-oral transmission is possible

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Cholera in the world, 1960-2005
Source WHO Weekly Epi Record
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Cholera CFR, 1960-2005
Source WHO Weekly Epi Record
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Presentation- Rice water diarrhea
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Presentation- Dehydration

• Hypotension
• Rapid thready pulse
• Loss of skin turgor
• Sunken eyes
• Thirst
• Altered mental status but arousable
• Anuria
• Renal failure

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Cholera Gravis

• Severe diarrhea
• Vomiting
• Muscle cramps (leg cramps)
• Dehydration
• Electrolyte imbalance
• Death

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Cholera Gravis

• Loss of 1 liter of fluid/hour
• gt10 of body weight
• Hypotension in 1 hour (usually 4-12 hours)
• Death in 2 hours (usually gt18 hours)

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Diagnosis

• Suspicion increased
• Adults with dehydrating diarrhea
• Deaths from dehydration
• Recent travel to affected area
• Recent consumption of high-risk foods
• Undercooked seafood i.e. crabs, etc.
• Lab confirmation of initial isolates!

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Diagnosis

• Stool culture Toxigenic Vibrio cholerae O1
• Use Cary Blair Transport media if available
• Viable for many days at room temperature
• Use TCBS media for culture
• Use V. cholerae serogroup O1 antisera
• Confirm presence of cholera toxin
• Cholera Rapid Test Dipsticks

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Role of Laboratory

• Confirmation of initial isolates in new areas
• Monitor antibiotic susceptibility
• Confirm when outbreak is over

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Treatment

• Treat all cases / suspect cases promptly
• Assess degree of dehydration
• Determine if rehydration should be oral or IV
• Dont wait for laboratory confirmation to treat
• Death rates from severe cholera can be decreased
  from 50 to lt1

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Effect of tetracycline treatment on duration of
diarrhea
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Recommended Antibiotics for Cholera
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Preparedness and control

• Cholera control committees
• Ensure access to treatment facilities
• Ensure adequate treatment supplies
• Surveillance
• Water and sanitation
• Epidemiologic investigation
• Public health education

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Surveillance

• Case definition
• Example acute (watery) diarrhea in a person gt5
  years old
• Laboratory confirmation of initial cases
• Simple and sustainable
• Dissemination of data
• Environmental testing

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When to investigate

• Increase in total cases of diarrhea
• Increase in cases of diarrhea in adults
• Deaths caused by dehydration
• Laboratory confirmation of cholera

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Epidemiologic investigation

• Ensure adequate treatment and surveillance
• Investigate modes of transmission
• Case-control studies
• Household surveys
• Environmental testing
• Investigate unusually high case-fatality rates
• Control measures based on investigations

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Preparedness

• Every health facility should have capacity for
  oral or IV rehydration
• Train community health workers
• identify patients
• provide ORS for mild-moderate cases
• redirect those with cholera gravis to health
  centers
• Goal- 90 of health care workers trained
• When and how to set up Cholera Treatment Centers

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Cholera Treatment Centers

• ORT Corners- need to be well identified
• Cholera Treatment Centers
• Should be ready before outbreak
• Supplies-
• 50 L water/ patient
• Buckets, cholera cots, disinfectants, rubber
  gloves, clothing/bedding

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Cholera Treatment Centers

• Cholera Treatment Centers
• Organization- 4 areas
• Selection and observation
• Hospitalization
• Convalescent room for ORS
• Neutral area (kitchen, materials)
• Disinfection area
• Safe disposal of excreta

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Diarrheal Kits

• Full treatment (4 modules)
• 100 cases of severe cholera
• Antibiotics for 65 adults and 60 children
• 400 mild or moderate cases in ORT
• 100 adults and 100 children with shigella
• Can purchase modules separately
• Total kit cost 5000 US

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Water

• Disinfection
• Central chlorination
• Home chlorination (storage containers)
• Boiling water
• Narrow necked water containers
• Eliminate sewage cross connections
• Ensure adequate quantities

• Chlorine deactivated in metal need to use
  plastic buckets

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Control measures

• Quarantine?
• No
• Mass chemoprophylaxis?
• No
• Antibiotic treatment of family contacts?
• Maybe
• Vaccine?
• Maybe?

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Cholera Vaccines

• 2 oral vaccines currently exist
• Limited protection after 1 year, based on age
• Available only for those gt2 years of age
• Require multiple doses, 150ml of water
• Cold chain
• 7.00 per immunized person in Darfur
• 18.00 per immunized person in Aceh

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Cholera Case Study