What is all this talk about explosive diarrhea?

There is a large, ongoing outbreak of cyclosporiasis, an intestinal infection caused by the parasite Cyclospora cayetanensis, affecting many U.S. states. Michigan has the most cases by far, with 1,251 reported and 44 hospitalizations as of early July 2026. The parasite spreads through food or water contaminated with human feces, and past outbreaks have been linked to fresh produce such as berries, bagged lettuce and other leafy greens, fresh herbs like cilantro, and snow or snap peas. The source of this outbreak has not yet been identified; pinpointing it requires slow, labor-intensive interviews with people who got sick, and extensive traceback efforts, so an answer may take time.

The hallmark symptom is watery, sometimes explosive, diarrhea that can persist for weeks if untreated, often with cramping, low-grade fever, and fatigue. Many people will recover on their own, but it can last a long time and be very unpleasant. It is treatable with a short course of antibiotics, which helps lessen the severity and duration. Dehydration is the main danger, particularly for young children, older adults, and people who are immunocompromised. Those who have had watery diarrhea for more than a few days should consider reaching out to a healthcare provider about Cyclospora testing.

Until the source is identified, the most effective way to lower risk is to cook produce thoroughly. You can also likely reduce risk by sticking to fruits and vegetables that have skin that can be vigorously washed and then peeled. Washing alone reduces risk but doesn’t eliminate it. For concern consumers and immunocompromised individuals, It is reasonable to consider limiting high-risk food categories that have been common sources in past outbreaks (e.g., raspberries, bagged salads, certain fresh herbs) and, when possible/reasonable, sourcing from local farms that are unlikely to be the source of a multi-state outbreak.

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