It is widely disseminated in nature in surface water, mammals, birds and reptiles. Transmission occurs from animals or water to man by the oral route. Diagnosis depends on demonstrating the acid fast oocysts in stool. Most common symptom is watery diarrhea with abdominal pain, anorexia and weight loss. Self limited disease in healthy individuals lasting 10-20 days.
Severe disease occurs in immunocompromised patients, esp.
Incubation period is 2-14 days. Asymptomatic shedding after infection lasts 5 weeks. Routine disinfectants in home or hospitals are not useful. Transmission directly from animals is rare but has been found in a cockroach in Peru where transmission occurred to a child. Sand filters in swimming pools are also not effective.