Cyclosporiasis is an intestinal illness caused by the parasite Cyclospora cayetanensis through ingestion of fecally contaminated food or water. Symptoms of cyclosporiasis might include watery diarrhea (most common), loss of appetite, weight loss, cramping, bloating, increased gas, nausea, and fatigue. Typically, increased numbers of cases are reported in the United States during spring and summer; since the mid-1990s, outbreaks have been identified and investigated almost every year. Past outbreaks have been associated with various types of imported fresh produce (e.g., basil, cilantro, and raspberries) (1). There are currently no validated molecular typing tools* to facilitate linking cases to each other, to food vehicles, or their sources. Therefore, cyclosporiasis outbreak investigations rely primarily on epidemiologic data.
The 2018 outbreak season is noteworthy for multiple outbreaks associated with different fresh produce items and the large number of reported cases. Two multistate outbreaks resulted in 761 laboratory-confirmed illnesses. The first outbreak, identified in June, was associated with prepackaged vegetable trays (containing broccoli, cauliflower, and carrots) sold at a convenience store chain in the Midwest; 250 laboratory-confirmed cases were reported in persons with exposures in three states (illness onset mid-May–mid-June) (2). The supplier voluntarily recalled the vegetable trays (3). The second multistate outbreak, identified in July, was associated with salads (containing carrots, romaine, and other leafy greens) sold at a fast food chain in the Midwest; 511 laboratory-confirmed cases during May–July occurred in persons with exposures in 11 states who reported consuming salads (4). The fast food chain voluntarily stopped selling salads at approximately 3,000 stores in 14 Midwest states that received the implicated salad mix from a common processing facility (5). The traceback investigation conducted by the Food and Drug Administration (FDA) did not identify a single source or potential point of contamination for either outbreak.