Cryptosporidiosis in immunocompetent patients presents as diarrhea lasting 2-28 days. It is transmitted by contaminated food and water (swimming & drinking), infected people, and contaminated surfaces. Oocysts can be removed from water by filtration or boiling, but not by chlorination.
CASES/YEAR
92,500 (US); 5,550,000 (Global)
OTHER NAMES
Cryptosporidium parvum infection; Cryptosporidium hominis infection;
INCUBATION
1 week with range of 1-30 days; [Cecil, p. 2103]
INITIAL SYMPTOMS
In immunocompetent patients: diarrhea lasting 2-28 days that may be associated with abdominal pain, nausea, myalgias, fatigue, headaches, and low grade fever; [Cohen]
PRECAUTIONS
"Use Contact Precautions for diapered or incontinent persons for the duration of illness or to control institutional outbreaks." [CDC 2007 Guideline for Isolation Precautions] "Excretion continues in stools for several weeks after symptoms resolve; outside the body, oocysts may remain infective for 2-6 months or longer in a moist environment." [CCDM, p. 137]
COMMENTS
FINDINGS:
Cryptosporidiosis causes a self-limited gastroenteritis that usually resolves in less than 30 days in immunologically healthy patients. Diarrhea and abdominal cramping are the most common symptoms. Biliary tract infection and cholecystitis occur in immunocompromised patients. [CCDM, p. 136] In developed countries, most patients are adults with 5-10 days of diarrhea, nausea, vomiting, cramping, and fever. In developing countries, most patients are children with diarrhea (lasting over 14 days in up to 45% of cases). Fever and cough are present in a minority of cases. Respiratory tract infections may occur in AIDS patients. [PPID, p. 3415-6] Lactoferrin is positive for fecal leukocytes in children and HIV infected but not healthy adults experimentally infected with C. parvum. [Guerrant, p. 638] In a series of cases, 11% had bloody diarrhea. [Cecil, p. 2103] Immunocompromised patients may develop infections of the respiratory tract, biliary tract, or rarely pancreas. Immunosuppressed HIV-infected patients may develop cholera-like diarrhea, wasting, and malabsorption. [CDC Travel, p. 193] Right upper quadrant pain in an AIDS patient suggests biliary tract involvement. [Guerrant, p. 636]
EPIDEMIOLOGY:
Transmitted by contaminated food and water (swimming & drinking), infected people, and contaminated surfaces. [CDC Travel, p. 192] Oocysts can be removed from water by filtration or boiling, but not by chlorination. [PPID, p. 3419] Men who have sex with men are at increased risk. Infection can occur in workers exposed to feces of infected farm animals (animal handlers) or to feces of infected children (daycare center employees). Reservoirs include over 45 vertebrate species including birds, fish, reptiles, and mammals. [CCDM, p. 137]
DIAGNOSTIC
Detect oocyst--IFA most sensitive and specific; "Must request detection of Cryptosporidia specifically on O&P specimen." Usually a single specimen is adequate. PCR available; [ABX Guide]
SCOPE
Global; One study found more commonly reported in travelers returning from Asia (particularly India) and Latin America; [CDC Travel]
SIGNS & SYMPTOMS
-
>arthralgia
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>fatigue, weakness
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>fever
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>myalgia
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G abdominal pain
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G blood in stool
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G diarrhea
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G fecal leukocytes
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G liver function test, abnormal
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G nausea, vomiting
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N headache
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R cough
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R dyspnea
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R sputum production
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X lung infiltrates
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*pancreatitis
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*pneumonia
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*weight loss
ENTRY
Ingestion, Swimming, Sexual Contact
SOURCE
Person-to-Person, Human Fecal-Oral, Eating Contaminated Food, Waterborne (Ingesting, Inhaling, or Swimming)
RESERVOIR
Birds and Poultry, Cattle, Goats and Sheep, Cats, Dogs, Fish and Shellfish, Horses, Rodents, Swine, Human, Wild Animals
RISK FACTORS
- AIDS patients
- Care for children or animals infected with cryptosporidiosis
- Ingest infectious agents in food/water
- Swim in contaminated water (ingestion or inhalation)
- Travel to endemic area
TREATMENT
"Most immunocompetent people recover without treatment. The US Food and Drug Administration has approved Nitazoxanide as a treatment for cryptosporidiosis in immunocompetent people aged >1 year." [CDC Travel]
REFERENCES FOR CASES/YEAR
1. (US) MMWR 2011: 9250 cases; 2.67 per 100,000 in 2007; [Gorbach, p. 10] Calculate 2.67 for population of 300 million = 8010; Use correction factor of 10 for reported diseases: 9,250 X 10 = 92,500;
2. (Global) Seroprevalence rates up to 25% in rich countries and 75% in poor countries; [Gorbach, p. 142] Calculate: 3 x 92500 = 277500 for global rate in US population of 300 million; Multiply x 20 for global population of 6 billion = 5550000;