The U.S. Food and Drug Administration's outbreak investigations page lists an active Cyclospora investigation — reference number 1375 — with cases increasing since the last update, and the source of contamination has not yet been identified. This is not the kind of headline that generates mass alarm, but it should generate immediate consumer awareness, because Cyclospora is a parasite that causes weeks of profuse watery diarrhea with fatigue and weight loss, because summer is its peak transmission season, and because the foods most frequently linked to Cyclospora outbreaks in the United States — bagged salads, fresh cilantro, basil, and leafy greens — are among the most commonly consumed summer foods in America.
Cyclospora cayetanensis is a microscopic parasite that infects the small intestine, causing a syndrome of profuse, often watery diarrhea that begins approximately one week after exposure and can last for weeks to months in untreated cases. Unlike most foodborne pathogens whose symptoms resolve in a few days, Cyclospora produces a characteristically prolonged illness — diarrhea cycles between profuse and less severe, with periods of temporary improvement that trick patients into thinking they are recovering before the diarrhea returns. Fatigue, nausea, appetite loss, bloating, and significant weight loss are common. In otherwise healthy adults, Cyclospora is rarely fatal — but it is profoundly debilitating, and it is responsible for a surprising number of hospitalizations each year.
