Michigan health officials are tracking 708 cases of explosive diarrhea parasites over about 10 days, with most illnesses centered in the southeastern part of Michigan. Dr. Natasha Bagdasarian said staff were pulling people’s grocery shopping lists as the count rose precipitously and investigators tried to identify what people had eaten.
The state’s case total is far above the 40 to 50 cyclosporiasis cases a year Michigan usually sees. Dr. Anurag Malani said the tally could easily reach 1,000, and some patients have needed hospitalization from dehydration.
Michigan and cyclospora
Cyclosporiasis is a foodborne illness caused by a microscopic parasite called cyclospora. Fresh produce is almost always the source, and previous outbreaks involved raspberries, bagged lettuce or salads, cilantro and basil. People may develop explosive, watery diarrhea, unusually bad gas, stomach cramps, nausea and loss of appetite.
Dr. Bagdasarian called the spike "highly unusual," and Dr. Brian Kaminski said cases in southeast Michigan and northwest Ohio appear to be part of an "epidemic cluster." He said, "When we started seeing cases of persistent diarrhea showing up, we knew there’s something going on" and added, "I would say that trend continues."
FDA and CDC tracking
The FDA said an investigation was ongoing. The CDC said cyclosporiasis cases tend to increase during the summer between May 1 and Aug. 31, and it reported 145 cases in 17 states from the beginning of May through June 16.
But the CDC also said it has no evidence of a single, multistate Cyclospora outbreak linking the cases being reported in the press. As of July 2025, the CDC made tracking cyclospora optional as part of scaling back its Foodborne Diseases Active Surveillance Network, which leaves the current search dependent on state and local tracing.
ProMedica Health System
As of Monday, ProMedica Health System accounted for 411 cases. Cyclosporiasis does not spread from person to person, and left untreated it can linger for weeks. It is treated with an antibiotic, usually Bactrim, so people in Michigan who develop persistent watery diarrhea after eating fresh produce need to seek care quickly and describe what they ate to investigators.
