Michigan Links Diarrhea Outbreak to Lettuce and Salad Greens

A growing outbreak of diarrhea caused by the parasite cyclospora has sickened over 3,000 people in Michigan and Ohio, with lettuce or salad greens emerging as a possible source. Michigan health officials report 2,640 cases, including 44 hospitalizations, while Ohio has reported 361 cases since June 1, with at least 46 hospitalizations. The investigation is ongoing, and while lettuce has been identified as a common product, no specific type, grower, or supplier has been pinpointed.

What happened

The outbreak has been reported in 31 states, with Michigan and Ohio having the highest numbers. The US Centers for Disease Control and Prevention (CDC) has reported 843 confirmed cases since May 1. Investigators face challenges in identifying the source due to the slow counting of cyclosporiasis cases and complicated genomic testing.

The CDC and public health systems have been impacted by staff and funding cuts, which have reduced surveillance capabilities. In 2025, the CDC scaled back its FoodNet system, which proactively looks for cases of foodborne illness.

Why it matters

The outbreak highlights the importance of robust public health surveillance and the challenges faced in identifying and responding to foodborne illnesses. The reduction in surveillance capabilities due to funding cuts may hinder the ability to track and contain outbreaks.

How to think about it

When considering food safety, it's essential to be aware of ongoing outbreaks and take precautions when handling and consuming produce. This includes washing fruits and vegetables thoroughly and being mindful of food recalls.

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