Michigan confirms rapid cyclosporiasis outbreak

Statewide spike

Michigan health officials say a cyclosporiasis outbreak is moving quickly, with more than 170 cases reported across at least seven counties as of June 30. The source has not yet been identified.

The Michigan Department of Health and Human Services and the Michigan Department of Agriculture and Rural Development are leading the investigation with local health departments. Dr. Natasha Bagdasarian, Michigan's chief medical executive, said additional cases are expected.

The case count is notable because Michigan typically identifies around 50 cyclosporiasis cases in a full year. Officials have said the current spike is unusually large and still developing.

How the investigation unfolded

The Monroe County Health Department first said a cluster of cyclosporiasis cases had been detected in the county during the past week, prompting concern about a shared exposure.

By June 30, state officials said cases had been reported in Monroe, Lenawee, Washtenaw, Wayne, Livingston, Shiawassee and Jackson counties. Regional reporting on July 1 said the outbreak had drawn wider attention as the investigation continued.

Officials have not announced a restaurant, distributor or specific food item linked to the illnesses. Interviews with patients are continuing as investigators look for a common exposure.

What cyclosporiasis is

Cyclosporiasis is caused by Cyclospora cayetanensis, a parasite spread through food or water contaminated with feces. It is not usually spread from person to person.

Symptoms can include sudden, ongoing diarrhea and may begin two to 14 days after exposure. The illness can last for weeks if untreated, but it usually improves with antibiotic treatment.

Public health officials say outbreaks like this one are often linked to contaminated fresh produce, although no source has been identified in Michigan.

What officials are watching next

Health departments are urging people with symptoms to contact a health care provider and their local health department. Investigators are trying to determine whether the same exposure explains cases across the affected counties.

Officials are also watching for any new case-count updates, whether the outbreak expands beyond the counties already named, and whether hospitalizations or other severe outcomes are reported.

For now, the central question remains unanswered: what caused the outbreak and whether the exposure is still ongoing.