Michigan Cyclosporiasis Outbreak: More Than 170 Cases Reported Across 17 Counties

Lindsay Knake
| 3 min read
Lindsay Knake is a brand journalist for Blue Cross B...

Key Takeaways
- Michigan health officials have confirmed more than 170 cases of cyclosporiasis in 17 counties in the past nine days, a sharp rise from the typical 50 cases a year.
- The parasite, spread through contaminated fresh produce or water, causes frequent diarrhea, abdominal cramps and other gastrointestinal symptoms.
- Officials urge residents to wash hands thoroughly and rinse all fruits and vegetables under running water, scrubbing firm produce and discarding bruised sections to reduce risk.
Michigan is experiencing a surge of an illness that causes diarrhea.
There have been more than 170 reported cases of cyclosporiasis across the state in the past nine days as of July 1, according to the Michigan Department of Health and Human Services (MDHHS). State and county health officials are investigating the source of the outbreak, which is confirmed in 17 counties in Michigan. Most cases are in Monroe, Lenawee, Washtenaw, Wayne, Livingston, Shiawassee and Jackson counties, and there are also reported cases in the city of Detroit. By comparison, Michigan usually has 50 reported cyclosporiasis cases per year.
This illness has been reported in people age eight to 84. The health department anticipates there will be more reported cases in coming days.
The outbreak in Michigan is part of a surge in cases in 16 additional states across the United States.
What is cyclosporiasis?
Cyclosporiasis is an intestinal illness caused by the parasite Cyclospora cayatenensis, which is spread by contaminated food or water contaminated with feces, per the U.S. Centers for Disease Control and Prevention (CDC). While the parasite and illness do not spread person to person, fresh produce has been a cause of the illness in the United States in recent years. The mild to moderate illness can last anywhere from a few days up to a month; however, it is usually not life-threatening.
What are the symptoms of cyclosporiasis?
Symptoms include:
- Frequent and sometimes explosive diarrhea
- Abdominal cramps
- Bloating
- Nausea and sometimes vomiting
- Loss of appetite
- Low-grade fever
Cyclosporiasis symptoms can be intermittent through the course of the illness.
If you have a sudden gastrointestinal illness, talk to your primary care provider (PCP). Antibiotics are a common treatment for cyclosporiasis, which can persist for several weeks if untreated for some people. The MDHHS is recommending physicians and health care providers consider cyclosporiasis as a reason for gastrointestinal illness in Southeast Michigan.
Those with the illness should drink plenty of fluids and get rest, according to the CDC.
What foods are linked to Cyclospora outbreaks?
While Michigan health officials are still looking for the cause of the 2026 outbreak, past sources of the Cyclospora cayatenensis in the U.S. include:
- Basil
- Cilantro
- Mesclun lettuce
- Raspberries
- Snow peas
- Sweet peas
How can you prevent cyclosporiasis?
To prevent contracting this illness, frequently wash your hands with soap and warm water, scrubbing for at least 20 seconds.
Because cyclosporiasis typically spreads through contaminated produce, the Michigan Department of Agriculture and Rural Development (MDARD) recommends taking the following steps to reduce your chance of contracting the parasite:
- Thoroughly wash all fruits and vegetables under running water before eating or cooking.
- Scrub firm produce such as melon with a clean produce brush.
- Remove damaged or bruised areas of produce before consuming.
- Refrigerate peeled, cut or cooked produce as quickly as possible.
Photo credit: Getty Images
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