A parasitic infection is causing ‘explosive diarrhea’ and other symptoms in Michigan and other states across the U.S. Cases have been on the rise since May 2026, and the source has yet to be identified.
The parasite Cyclospora cayetanensis can cause an infection known as cyclosporiasis, and, according to the Michigan Department of Health & Human Services (MDHHS), as of June 30, 2026, 170 cases have been reported in the state. Michigan only sees about 50 cases of cyclosporiasis each year, and health experts believe that with an outbreak this size, more cases will likely pop up.
“Outbreaks of cyclosporiasis have been occurring across the United States and now here in Michigan,” said Natasha Bagdasarian, chief medical executive at the MDHHS, in a press release. “Based on the unusual number of cases we have identified in a little over a week, we anticipate additional cases of illness being reported. We recommend Michiganders contact their health care provider if they experience sudden, ongoing diarrhea and reach out to their local health department if additional members of their family are suffering from the same symptoms.”
The infection can spread through contaminated food, especially during the summer. Here’s what you need to know.
Explore All OptionsWhat Is Cyclosporiasis and What Are The Symptoms?
Cyclosporiasis, according to the Cleveland Clinic, is a type of food poisoning caused by the parasite C. cayetanensis. While cases do occur in the U.S. — there were just over 1,000 in 2025 — the infection is more common in subtropical or tropical regions, such as Asia, Africa, Central and South America, and parts of Europe.
According to the Cleveland Clinic, the infection is not usually life-threatening, and while anyone can be infected, it has a greater impact on children, older adults, and those who are immunocompromised. The symptoms are similar to those of other forms of food poisoning and include nausea, vomiting, fever, fatigue, loss of appetite, and stomach cramps.
However, the main symptom is explosive, loud, and watery diarrhea.
These symptoms can lead to severe dehydration and electrolyte imbalance. The best way to know for sure if you have cyclosporiasis is to see a doctor.
How Does Cyclosporiasis Spread?
The parasite spreads through contaminated water and food sources — typically from germs in contaminated poop. Since it is a microscopic organism, a person can’t see it with the naked eye. The parasite can often live on foods such as fruits and vegetables and can be accidentally consumed if produce is unwashed. It may also be ingested through untreated water. According to the Cleveland Clinic, the parasite can even live in chlorinated pool water for some time.
Infection rates can depend on where one lives and travels. Living in or traveling to areas where outbreaks are more common increases the risk of contracting the parasite. However, it's sometimes possible to contract cyclosporiasis from imported foods. Produce, including basil, raspberries, sweet peas, snow peas, cilantro, and mesclun lettuce, has been linked to past cases of cyclosporiasis in the U.S.
There is no evidence that the infection spreads from human to human.
Cyclosporiasis Treatments and How to Avoid It
Medical professionals often treat cyclosporiasis with antibiotics like trimethoprim/sulfamethoxazole. In some cases, a doctor may recommend taking an antidiarrheal medication to help slow dehydration and keep food in the body. Doctors may also recommend increasing fluid intake, such as water and electrolyte-rich sports drinks.
Cyclosporiasis may go away on its own, but symptoms may remain. Most people recover within a week or two with proper medical care and diagnosis, but some cases can last up to a month. Unfortunately, the diarrhea can sometimes continue in bouts for about a month after.
To prevent cyclosporiasis, the MDHHS suggests thoroughly washing all produce under running water before cooking, cutting, and eating. Using a clean produce brush to firmly scrub firm fruits and vegetables like melons and cucumbers. Keep produce peeled and cut in the refrigerator, and cut off bruised or damaged areas on produce before consuming.
This article is not offering medical advice and should be used for informational purposes only.
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- This article references information from the Michigan Department of Health and Human Services: Outbreak of cyclosporiasis occurring in Michigan
- This article references information from the Cleveland Clinic: Cyclosporiasis
