CDC Case Definition

What is a "Case Definition"?

Overview of Public Health Surveillance

During May-June 1998, the Ontario Ministry of Health and local health departments in Ontario received reports of clusters of cases of cyclosporiasis associated with events held during May. This report describes the preliminary findings of the investigation of a cluster in Toronto, Ontario, and summarizes the findings from investigations of 12 other clusters.

During July 1997, state and local health departments in Virginia, the District of Columbia (DC), and Maryland received reports of clusters of cases of cyclosporiasis associated with events (e.g., luncheons) held in their jurisdictions during June and July. This report describes the preliminary findings of the investigation of a cluster in Virginia and summarizes the findings from ongoing investigations of the other clusters. Fresh basil has been implicated as the probable vehicle of infection.

Since April 1997, CDC has received reports of outbreaks of cyclosporiasis in the United States and Canada (1,2). As of June 11, there have been 21 clusters of cases of cyclosporiasis reported from eight states (California, Florida, Maryland, Nebraska, Nevada, New York, Rhode Island, and Texas) and one province in Canada (Ontario). These clusters were associated with events (e.g., receptions, banquets, or time-place-related exposures {meals in the same restaurant on the same day}) that occurred during March 19-May 25 and comprise approximately 140 laboratory-confirmed and 370 clinically defined cases of cyclosporiasis.

During April and May 1997, CDC received reports of clusters of cases of cyclosporiasis in the United States (1). This report describes the preliminary findings of an investigation of an outbreak in New York and summarizes the findings from on-going investigations in other states.

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, 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.

Until 1996, most cases of cyclosporiasis in the United States occurred among international travelers, and information about modes of transmission of C. cayetanensis was limited. Waterborne transmission had been documented, but direct person-to-person transmission was considered unlikely. During the summer of 1995, in response to an outbreak of Cyclospora infection among Florida residents with no history of international travel, the state health department initiated surveillance for the organism.

Since May 1996, CDC has received reports of clusters and sporadic cases of infection with the parasite Cyclospora cayetanensis that occurred in May and June in the United States and Canada. This report describes preliminary findings of an investigation by the New Jersey Department of Health and Senior Services (NJDHSS) and updates the findings of other ongoing investigations.

Cyclospora cayetanensis (previously termed cyanobacterium-like body) is a recently characterized coccidian parasite; the first known cases of infection in humans were diagnosed in 1977. Before 1996, only three outbreaks of Cyclospora infection had been reported in the United States. This report describes the preliminary findings of an ongoing outbreak investigation by the South Carolina Department of Health and Environmental Control (SCDHEC) and summarizes the findings from investigations in other states.

FDA has released a talk paper on outbreaks of cyclosporiasis and Guatemalan raspberries.