Michigan cyclosporiasis outbreak tops 10,000 cases; 33 additional hospitalizations in past week

An additional 33 Michigan residents have required hospital care for cyclosporiasis as an outbreak continues to be tracked, state health officials said on Thursday

Tracking of an outbreak of the intestinal ailment began in the state on June 22. The Michigan Department of Health and Human Services says it has counted 10,386 cases as of July 30; up 309 from the 10,077 case reports on July 29. The number has been increasing by the hundreds each day

Health officials say 193 people among those patients have been hospitalized, compared to the 160 hospital cases reported on July 23. 

Cyclospora cayetanensis is a parasite that causes the diarrheal illness cyclosporiasis. The Centers for Disease Control and Prevention says the most common symptoms associated with the illness are frequent watery diarrhea, loss of appetite, bloating, nausea and fatigue. Some people may also experience body aches, headache or vomiting. 

The outbreak was first identified in Monroe County in late June and has since spread to 70 Michigan counties, with Southeast Michigan bearing the heaviest burden. Wayne County alone has reported more than 1,000 cases. Eaton, Genesee, Ingham, Lenawee, Monroe, Oakland, Shiawassee, Washtenaw and Wayne counties are all reporting more than 300 cases each. 

Michigan sees around 50 cases of cyclosporiasis per year

Michigan health officials report case numbers Monday through Friday. Hospital reports are updated once a week on Thursdays. The numbers reported on July 27 included about 475 cases that were “not previously reported to MDHHS due to delayed laboratory reporting,” the agency said

Symptoms of cyclosporiasis 

Cyclosporiasis is caused by the parasite Cyclospora cayetanensis and spreads when infected feces contaminate food or water.   

Health officials say symptoms typically begin about a week after infection and include frequent watery diarrhea, loss of appetite, bloating, nausea and fatigue, lasting from two days to two weeks or longer.  

“Without treatment, illness can last for weeks and may come and go,” Wayne County health officials said.   

What’s causing the cyclosporiasis outbreak?  

Michigan officials said on July 13 that testing pointed to lettuce or salad greens as a potential

On July 24, the Centers for Disease Control said a lettuce supplier to fast-food giant Taco Bell has been linked to the outbreak. However, federal officials said there are multiple clusters of the ailment active in the United States. 

At the local level, the Wayne County Public Health agency in Michigan said on July 30 that it is reaching out to community residents with a survey to gather more information about the outbreak. “If we contact you, please take a few minutes to answer our questions. Your response helps us identify possible County Public Health said

Public reaction to the cyclosporiasis outbreak

A CBS News poll from July 26 that four in 10 Americans are buying or eating less produce because of the parasite.  

Lettuce sales at supermarkets, along with visits to several food and restaurant chains where popular menu items include lettuce, have also declined since the outbreak began, CBS News found

Tips to prevent cyclosporiasis

Michigan health officials shared the following tips for avoiding the illness:

• Wash all fruits and vegetables thoroughly, under running water, before cutting, cooking or eating.
• Scrub firm fruits and vegetables, such as melons and cucumbers, with a produce brush when cleaning.
• Cut away any damaged or bruised areas of produce before preparing and eating.
• Refrigerate any cut, peeled or cooked produce within two hours of preparing it.

The above video originally aired on July 27, 2026