A multistate Cyclospora outbreak linked to recalled iceberg lettuce has infected at least 1,947 people across nine states, making it one of the largest outbreaks of the parasite ever recorded in the United States. The agency is also investigating other Cyclospora outbreaks and illnesses occurring nationwide that are unrelated to this investigation. Cyclospora is a microscopic parasite (Cyclospora cayetanensis) that infects the small intestine and causes an illness known as cyclosporiasis. Largest Outbreaks of CyclosporaAlthough the investigation remains ongoing, the spread has already become one of the largest documented Cyclospora outbreaks in U.S. history. A History of Major Cyclospora OutbreaksCyclospora was rarely recognized as a foodborne illness in North America until the mid-1990s after a widespread outbreak linked to Guatemalan raspberries.