Domestically Acquired Cyclosporiasis Cases in Multiple U.S. States, 2026

This CDC health advisory concerns a sharp rise in cyclosporiasis, a gastrointestinal illness caused by the microscopic parasite Cyclospora. People become infected by consuming contaminated food or water — previous outbreaks have been linked to fresh produce — and the illness does not usually spread from person to person. CDC considers May 1 to August 31 the annual cyclosporiasis season.

Since May 1, 2026, CDC has received reports of 1,645 confirmed domestic cases across 34 states — substantially higher than the 249 cases reported nationally by the same time last year. Of the case-patients with available information, 141 (about 9%) were hospitalized, and no deaths have been reported. Reported patients range in age from 2 to 95 years.

For parents, the key signs to watch for are watery diarrhea (which can be frequent), loss of appetite, weight loss, bloating, nausea, and fatigue, typically beginning about one week after exposure. Without treatment, symptoms can follow a relapsing course lasting from a few days to a month or longer. If your child has prolonged or relapsing watery diarrhea, contact your pediatrician — and note that routine stool tests may not reliably detect this parasite, so testing specifically for Cyclospora may need to be requested. Effective treatment is available; see the official CDC notice for details and current guidance.