Cryptosporidium parvum

Aka: Cryptosporidium parvum, Cryptosporidium

1. See Also
   1. Diarrhea
   2. Infectious Diarrhea
2. Epidemiology
   1. Natural Hosts: young animals (e.g. calves)
   2. Waterborne Illness outbreaks
      1. Milwaukee contaminated municipal water (n=400,000)
      2. Florida Summer Camp with contaminated outdoor faucet
      3. References
         1. N Engl J Med (1994) 331:161
         2. MMWR (1996) 45:442-5
   3. Advanced HIV patients affected: 10-20%
3. Risk Factors
   1. Day care center attendance
   2. Human Immunodeficiency Virus (HIV) infection
4. Pathophysiology
   1. Coccidian protozoan present in animal feces
      1. Farm animals
      2. Domestic pets
   2. Very low inoculum required: 10 Oocysts
   3. Immunocompetent host has only mild Diarrheal illness
   4. AIDS patients
      1. CD4 Count <200: Chronic, persistent Diarrhea
      2. CD4 Count <140: More severe symptoms
5. Symptoms
   1. Normal Host
      1. Diarrhea
      2. Abdominal Pain
      3. Nausea or Vomiting
      4. Fever
   2. HIV Infection
      1. Chronic, persistent, secretory, watery Diarrhea
6. Course
   1. Symptom onset delayed 2-10 days from exposure
   2. Diarrhea persists for 10 days in normal host
7. Complications: HIV Infection
   1. Chronic biliary tract disease (sclerosing Cholangitis)
8. Management
   1. Very resistant to halogens
   2. HIV Infection
      1. Azithromycin
         1. High dose may be effective
      2. Paromomycin 500 to 750 mg PO tid to qid
         1. Oral Aminoglycoside with poor systemic absorption
      3. Metronidazole
         1. May be effective in reducing Diarrhea
9. Prevention
   1. Water filters or boiling water reduces infection risk
10. References
    1. Weller (2001) BMJ 322:1350-4