Michigan is experiencing a rapid surge in infections from the intestinal parasite Cyclospora cayetanensis, with 700+ confirmed cases and 36 hospitalizations as of July 6. The outbreak, first detected on June 22, accelerated sharply: cases jumped from 170 on June 30 to 572 by July 4 before surpassing 700 days later. The Michigan Department of Health and Human Services (MDHSS) reports no identified source yet, though past outbreaks have been tied to bagged salad mixes, cilantro, basil, raspberries, snow peas, and green onions.

Cyclosporiasis causes watery, sometimes explosive diarrhea lasting up to two weeks or more, with dehydration posing the main health risk. The parasite spreads via fecal contamination of produce or water, making proper washing and hand hygiene critical prevention measures. State officials are conducting a large-scale investigation alongside local health departments in southeastern Michigan, where most cases cluster.

MDHSS is sharing data with the CDC and conducting detailed interviews to pinpoint shared exposures. No specific grower, supplier, or produce type has been linked so far. Consumers in the affected region are advised to remain vigilant about produce handling and hygiene, especially as the investigation continues without a confirmed origin.

This outbreak highlights ongoing vulnerabilities in fresh produce supply chain safety and underscores the need for robust traceback capabilities when pathogens evade routine testing.