Cyclosporiasis outbreak in the US, by the numbers

July 22, 2026 - 02:21

A significant outbreak of cyclosporiasis, a diarrheal illness caused by the microscopic parasite Cyclospora cayetanensis, is expanding across several states in the US. Health officials are tracking a sharp increase in reported infections, with the parasite typically finding its way into the body through contaminated fresh produce or water.

The numbers paint a concerning picture. As of the latest reports, hundreds of confirmed cases have been documented, with the count climbing steadily over recent weeks. While cyclosporiasis is not new to the country, the current outbreak has hit a wider geographic area than usual. States in the Midwest and Northeast are reporting the highest numbers, though health departments in other regions are also investigating potential cases. The illness often strikes during the warmer months, from spring through early fall, which aligns with the current surge.

Symptoms of cyclosporiasis include watery diarrhea, loss of appetite, stomach cramps, nausea, and fatigue. In severe cases, the diarrhea can last for weeks if left untreated, leading to dehydration. The parasite is resilient and can survive on fruits, vegetables, and herbs that are eaten raw. Officials have not yet pinpointed a single source of the contamination, but they are urging consumers to wash all fresh produce thoroughly and to be aware of the symptoms, especially if they have recently traveled or eaten imported foods.

Public health agencies are working to trace the outbreak back to its origin, but the investigation is complicated by the long incubation period of the parasite, which can take a week or more to cause illness after exposure. For now, the best defense is careful food handling and seeking medical attention if symptoms persist.