Cryptosporidiosis

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Cryptosporidiosis
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Infectious Agent

• Protozoan
• Cryptosporidium parvum

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Reservoir

• Humans
• Cattle
• Other domestic animals

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Life Cycle
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Life Cycle
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Mode of Transmission

• Fecal-oral
• Person to person
• esp. child care settings
• Waterborne
• RWIs, both natural and swimming pools
• Drinking water
• Foodborne

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Susceptible Individuals

• Immunocompromised
• Young children
• Pregnant women
• AIDS patients

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Symptoms

• Diarrhea
• Weight loss
• Dehydration
• Stomach cramps
• Fever
• Nausea
• Vomiting

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Important Considerations

• Incubation-1 to 12 days
• Oocysts survive extreme conditions
• Oocysts infective for 2-6 months in environment
• Oocysts are 4-5 microns
• Infection may result from 10 oocysts

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Important Considerations

• Oocysts in stool appear with symptom onset
• Oocysts are immediately infectious
• Oocysts shed for several weeks after symptoms
  resolve
• Asymptomatic infections appear to be common

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Treatment

• Self-limiting in healthy individuals
• Drink fluids to prevent dehydration
• A new drug, nitazoxanide, has been approved for
  treatment of diarrhea

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Milwaukee 1993

• Largest documented waterborne outbreak in U.S.
  history
• 403,000 cases
• 111 deaths

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Causes of Milwaukee Incident

• Livestock runoff from record rainfalls entered
  Milwaukee River
• Poor design-Drinking water influent too close to
  wastewater effluent
• Human errors in drinking water plant

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Milwaukee Illness

• Watery diarrhea (93)
• Median stools/day12 (range 1 to 90)
• Abdominal cramps (84)
• Fever (57)
• Vomiting (48)

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Recreational Water Illness

• 10 documented outbreaks since 1988
• Contamination by AFRs
• Highly resistant to chlorination

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Foodborne Outbreaks

• 1993-Unpasteurized apple cider---apples fell in
  cow pasture
• 1995-Chicken salad-contamination by food worker
  operating home day care
• 1996-Commercially produced unpasterurized apple
  cider-contamination by washing with well water
  having fecal contamination

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General Prevention

• Do not swallow recreational water
• Do not drink untreated water
• Lakes, rivers, streams, untested wells
• Travelers and hikers
• Boil water for 1 minute or use NSF filter rated
  for cyst removal. Dont rely on chemical
  treatments
• Do not swim with GI infection

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Foodborne Prevention

• Thoroughly wash all produce
• No bare hand contact of ready-to-eat foods
• No food workers with GI illness
• Until 2 weeks after end of diarrhea
• Handwashing-handwashing-handwashing