Map tracks spread of 'explosive' diarrhea outbreak. How to prevent infection

Michigan and at least two dozen other states are reporting rising cases of cyclosporiasis, a foodborne infection caused by a stomach parasite that causes severe and sometimes explosive diarrhea.

More than 1,000 infections have been reported as of July 9, according to STAT, a health and medical news source which cited Associated Press reports. Michigan has officially reported 1,251 cases to date.

Cyclosporiasis is usually not considered a life-threatening disease, though it can cause severe dehydration.

The illness is caused by consuming the microscopic parasite Cyclospora cayetanensis while ingesting contaminated food or water. It's generally not transmitted directly from one person to another.

Here's where cyclosporiasis has been reported and how to protect yourself.

States reporting cyclosporiasis illnesses

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How can I protect myself from cyclosporiasis?

To reduce the risk of cyclosporiasis, health officials have issued guidance aimed at anyone involved in preparing, processing or serving fresh produce:

Other ways to reduce your risk of food-borne illnesses:

• Scrub firm produce like melons and cucumbers with a clean brush.
• Cut away bruised or damaged areas before eating.
• Clean and sanitize utensils and food-prep surfaces before and after use.
• Sanitize display cases and refrigerators used to store fresh produce.
• Clean and sanitize cutting boards and tools used with fresh produce.
• Refrigerate cut, peeled or cooked fruits and vegetables promptly.

While most bacterial foodborne illnesses resolve within a few days, cyclosporiasis can lead to gastrointestinal symptoms that persist for weeks or even longer, according to the Food and Drug Administration.

CONTRIBUTING: Mary Walrath-Holdridge, USA TODAY

SOURCE: USA TODAY Network reporting and research; Reuters; Centers for Disease Control and Prevention; Food and Drug Administration

This article originally appeared on USA TODAY: Map tracks spread of 'explosive' diarrhea outbreak. How to prevent infection

Reporting by Janet Loehrke and George Petras, USA TODAY / USA TODAY

USA TODAY Network via Reuters Connect

Copyright Reuters or USA Today Network via Reuters Connect

This story was originally published July 9, 2026 at 2:34 PM.