Michigan health officials warn of ‘large and growing outbreak’ of cyclosporiasis

July 1, 2026 - 18:45

State health authorities are warning the public about what they describe as a large and growing outbreak of cyclosporiasis, a parasitic intestinal illness. As of the latest update, more than 170 confirmed cases have been reported across Michigan, with officials still working to pinpoint the source of the contamination. The outbreak has spread across multiple counties, prompting a coordinated investigation by the Michigan Department of Health and Human Services and local health departments.

Cyclosporiasis is caused by the Cyclospora cayetanensis parasite, which is typically spread through contaminated food or water. Symptoms include watery diarrhea, stomach cramps, nausea, and fatigue, often lasting several weeks if untreated. Health officials urge anyone experiencing these symptoms, especially after consuming fresh produce or imported foods, to seek medical testing. The infection is treatable with specific antibiotics, but diagnosis requires a specialized stool test that is not part of routine lab work.

Investigators are interviewing patients and analyzing food histories to trace the outbreak to a common source. Past cyclosporiasis outbreaks in the U.S. have been linked to imported fresh produce like cilantro, raspberries, and salad mixes. While no specific food item has been confirmed yet, officials advise washing all fruits and vegetables thoroughly and cooking foods when possible. The public is encouraged to report any suspected cases to their local health department. This outbreak serves as a reminder of the importance of food safety practices, especially during warmer months when the parasite is more active.