Michigan cases of intestinal disease from parasite soar to over 2,600

Michigan health officials on Monday reported 2,640 cases linked to an outbreak of cyclosporiasis, an intestinal infection from the cyclospora parasite that often occurs through contaminated food or water, an increase of more than 1,000 cases since its last update on Friday.

The outbreak has resulted in 44 hospitalizations, according to the Michigan Department of Health and Human Services' latest update. No deaths have been reported.

The infection which has spread rapidly in Michigan since it began in May and has been detected in dozens of states, remains under investigation.

Michigan health officials said current evidence points to lettuce or other salad greens as a potential source of the outbreak, although investigators have not completely ruled out other food items. They added that no specific type of produce, grower or supplier has been linked to the outbreak.

Past outbreaks have occurred with fresh food including bagged salad mixes and some herbs, Michigan said.

Cyclosporiasis infections typically increase during the spring and summer months, with the season running from May through August, according to the U.S. Centers for Disease Control and Prevention.

The CDC said on its website dated July 9 that 843 people across 31 states had contracted the parasite, and 86 of them had been hospitalized. At that time, the agency said more than 1,500 additional cases required further analysis and confirmation.

The CDC did not respond to a request to comment on Michigan's report.

Michigan did not respond to a request for comment on whether all cases had been verified through testing.

The symptoms usually manifest within several days of eating the contaminated food, and include diarrhea, stomach cramps, nausea and fatigue. If not treated, the illness may last from a few days to a month or longer and may recur after symptoms initially subside, the CDC said.

The CDC has said that its surveillance figures include only laboratory-confirmed cases reported by states while state data may include both probable and confirmed cases, potentially resulting in higher case counts.

(Reporting by Mariam Sunny in Bengaluru; Editing by Caroline Humer and Mark Porter)

Copyright Reuters or USA Today Network via Reuters Connect.

This story was originally published July 13, 2026 at 1:40 PM.