Cyclosporiasis Outbreak in Michigan linked to Unknown Source

Michigan, United States

Update July 1st, 2026:
Michigan health officials have expanded the investigation into the cyclosporiasis outbreak. The Michigan Department of Health and Human Services (MDHHS) and the Michigan Department of Agriculture and Rural Development (MDARD), in collaboration with local health departments, are now investigating a large, multi-county outbreak.

As of June 30, 2026, more than 170 cases have been reported across Monroe, Lenawee, Washtenaw, Wayne, Livingston, Shiawassee, and Jackson counties, with additional cases reported in 11 other counties and the City of Detroit. Monroe County remains the most affected, reporting 70 cases.

Health officials have not yet identified a common source of exposure and continue interviewing patients to determine whether the illnesses are linked. While not all reported cases may ultimately be associated with the same outbreak, investigators note that the number of illnesses reported over the past nine days is far higher than Michigan's typical annual total of about 50 cyclosporiasis cases.

Officials continue to advise residents to seek medical care if they develop persistent diarrhea or other symptoms consistent with cyclosporiasis and recommend thoroughly washing fresh produce and following safe food handling practices while the investigation remains ongoing.

Source: Michigan Department of Health and Human Services (MDHHS)


June 29th, 2026:
The Monroe County Health Department is investigating a cyclosporiasis outbreak affecting several residents in the area. The illness, caused by the Cyclospora cayetanensis parasite, has been confirmed in multiple cases, with symptoms emerging over the past week.

The health department is actively working to identify a common source of exposure among the affected individuals. Cyclosporiasis is typically linked to consuming contaminated food or water, often fresh produce. The illness is not transmitted from person to person, but outbreaks have been noted in the U.S. during the summer months due to contaminated produce.

The outbreak was identified following reports of symptoms consistent with cyclosporiasis, such as watery diarrhea, loss of appetite, and abdominal cramps. Health officials urge anyone experiencing these symptoms to seek medical attention for proper diagnosis and treatment. The investigation is ongoing as authorities aim to prevent further cases.

Source: www.co.monroe.mi.us/DocumentCenter/View/6114/MCHD-cyclosporiasis-PR-6292026
Update July 1st, 2026: www.michigan.gov/mdhhs/inside-mdhhs/newsroom/2026/07/01/cyclosporiasis