IN APRIL and May 1997, CDC received reports of seven event-associated clusters of cases of cyclosporiasis from five states (California, Florida, Nevada, New York, and Texas). Approximately 80 cases of infection with human-associated Cyclospora, a recently characterized coccidian parasite,1 have been laboratory-confirmed. State and local health departments, CDC, and the Food and Drug Administration are conducting investigations to identify the vehicles of infection.
Both foodborne and waterborne outbreaks of cyclosporiasis have previously been reported in the United States during spring and summer months.2-4 In 1996, a total of 978 laboratory-confirmed cases of cyclosporiasis in the United States and Canada were reported in association with a widespread foodborne outbreak.3 The average incubation period of cyclosporiasis is 1 week. Illness can be protracted (from days to weeks) with frequent, watery stools and other gastrointestinal symptoms; symptoms may remit and relapse. Health-care providers should consider Cyclospora infection in