—
More than 700 Michiganders have fallen ill with cyclosporiasis, a severe stomach bug linked to parasites found in food or water, and health officials warn the worst may not be over.
The Michigan Department of Health and Human Services (MDHHS) has received more than 700 reports of cyclosporiasis since June 22, with 36 hospitalizations connected to the outbreak.
Disease detectives across the state are working to identify the source of the infections, while Detroit’s Health Department monitors cases locally as numbers rise daily.
‘One of the largest we’ve ever had’
Dr. Matthew Sims, director of Infectious Diseases Research at Corewell Health, says the scale of this outbreak is unprecedented for the state.
“This is one of the largest we’ve ever had in Michigan,” Sims said.
The case count continues to climb. Sims points to testing data to underscore just how dramatic the spike has been.
“In the previous year, we sent a total of 36 tests for Cyclospora; none of them were positive,” he said. “So far this year, as of yesterday, there were 26, and 15 were positive, so it’s a lot more testing and a lot more positives.”
He expects to see even more positive cases in the days ahead.
Where cases are concentrated
The outbreak has affected communities across Michigan, with the highest case counts in Monroe County (173), Washtenaw County (95), and Lenawee County (86). Wayne County, which includes Detroit, has reported 58 cases, with an additional six cases recorded specifically within Detroit city limits.
Cases have been reported in at least 35 counties across the state.
MDHHS notes that the numbers are constantly fluctuating and should not be interpreted as real-time case counts; data were last updated at 4:30 p.m. July 6.
Produce suspected, but source still unknown
Health officials suspect contaminated produce is to blame, though no specific fruit, vegetable, grower, or supplier has been identified.
MDHHS confirmed Monday that no specific produce source has been pinpointed at this time.
Past outbreaks offer some clues about where to look.
“Bagged lettuce, basil, raspberries bagged lettuce is a big one because you don’t cook it; it already comes washed,” Sims said.
Dr. Claudia Richardson, medical director for Detroit’s Health Department, says everyone should take extra precautions when handling and eating produce right now.
“I would rinse it thoroughly, immerse in water, vinegar,” Richardson said.
She also offered some reassurance about how the illness spreads.
“It’s not something that’s passed from person to person,” Richardson said. She added: “With produce, pay extra attention at this time with this outbreak going on — we want them to thoroughly wash your produce.”
When to see a doctor
For those who do contract cyclosporiasis, the experience can be miserable.
Sims says it’s important to know when symptoms warrant medical attention.
“If you have diarrhea that lasts for more than a day or so, or you’re getting dehydrated and can’t keep up with their food, that’s the time to see a doctor,” Sims said, noting fever or blood as additional warning signs.
MDHHS echoed that guidance, urging anyone experiencing gastrointestinal illness, such as sudden or ongoing diarrhea, to contact their health care provider and local health department.
The good news: antibiotics are available and can help treat the illness.
Doctors also suggest washing hands frequently and after handling produce.
Copyright 2026 by WDIV ClickOnDetroit – All rights reserved.
