New Delhi, July 12 -- A diarrheal illness caused by the microscopic parasite Cyclospora cayetanensis is spreading across the United States, with health officials reporting a sharp rise in infections during the 2026 outbreak season.

According to the US Centers for Disease Control and Prevention (CDC), 843 laboratory-confirmed domestically acquired cases of cyclosporiasis have been reported across 31 states as of July 9. The agency is also reviewing more than 1,500 additional suspected cases, meaning the actual number of infections could be significantly higher.

Here's what you need to know.

The CDC says several states have reported a noticeable increase in cyclosporiasis cases over the past two weeks compared with the same period last y...