A parasitic infection causing severe diarrhea has spread to more than half of US states, with thousands of people affected in recent weeks. The Centers for Disease Control and Prevention (CDC) confirmed 843 cases of cyclosporiasis between May 1 and July 9, while over 1,500 additional suspected cases are under review. Michigan has reported the most severe situation, with over 1,000 infections in two weeks, followed by New York, Ohio, and Illinois. Although 86 people have been hospitalized, no deaths have been reported so far.

The infection is caused by the microscopic parasite Cyclospora, which spreads through contaminated food or water. The CDC said all patients had eaten within the United States and none had recently traveled abroad. The exact source of contamination remains unknown, though past outbreaks have been linked to raw fruits and vegetables. Health experts note that the parasite does not spread directly from person to person.

Authorities in Michigan and the CDC have urged the public to wash fruits and vegetables thoroughly and seek medical advice if experiencing persistent diarrhea, as the number of infections is expected to rise with ongoing investigations.