A parasitic intestinal illness has swept through Michigan at a pace state health officials say is nearly 20 times higher than anything the state has seen before. As of 9:30 a.m. on July 8, 2026, the Michigan Department of Health and Human Services (MDHHS) confirmed 992 cases of cyclosporiasis since June 22 — up from just 700 cases reported two days earlier. At least 36 people have been hospitalized.
No specific food, grower, or supplier has yet been identified as the source. The outbreak is centered in southeast Michigan but has now spread to neighboring states, triggering investigations across at least 28 other states, including Ohio, New York, and Illinois.
Why This Matters
In a typical year, Michigan records roughly 40 to 50 Cyclospora cases. The current outbreak surpassed that annual average in its first week alone. Unlike common foodborne illnesses such as salmonella, cyclosporiasis does not resolve on its own. Without antibiotic treatment, symptoms can persist for weeks to more than a month.
The illness matters to everyday consumers because Cyclospora is most commonly spread through fresh fruits and vegetables — the kind of produce found in home refrigerators, restaurant kitchens, and school cafeterias.
"Anyone experiencing gastrointestinal illness, such as sudden and ongoing diarrhea, should contact their health care provider and their local health department," MDHHS said in a statement this week.
What We Know So Far
The MDHHS reported 992 confirmed cyclosporiasis cases as of 9:30 a.m. on July 8, 2026, with 36 hospitalizations. The outbreak was first made public in late June after Monroe County health officials began investigating a cluster of cases. The case count stood at 170 on June 30, then exceeded 700 by July 6 before reaching 992 just 48 hours later.
The majority of cases are concentrated in southeast Michigan. According to MDHHS, the counties with the highest case burdens are Monroe, Lenawee, Washtenaw, Wayne, Shiawassee, Jackson, Oakland, and Livingston.
Ohio's Department of Health confirmed at least 177 cases — 171 of which occurred since late June, suggesting the Ohio cluster is part of the same wave affecting Michigan. Investigations into similar illnesses are also underway in at least 28 other states.
Where the Risk Is Highest
The outbreak is most heavily concentrated in southeast Michigan — a region that includes the Detroit metro area and its surrounding suburbs. Monroe, Lenawee, and Washtenaw counties have reported the largest case clusters.
Dr. Brian Kaminski, vice president of medical affairs at ProMedica Health System, told NBC News that the surge in cases across both Michigan and Ohio may represent an "epidemic cluster" with a common source.
Michigan's chief medical executive, Dr. Natasha Bagdasarian, acknowledged that the state's aggressive investigation and case-reporting infrastructure may be "part of the reason why this looks like a Michigan problem" — meaning other states could be undercounting.
What Doctors and Experts Say
Dr. Natasha Bagdasarian told ABC News that the department's working hypothesis is the outbreak is linked to contaminated produce.
Dr. Teena Chopra, a professor of infectious disease at Wayne State University, told WXYZ Detroit that identifying the source of Cyclospora outbreaks is challenging because of the parasite's incubation window: "Usually after infection, it can take anywhere from one to two weeks for the symptoms to be seen — and by that time, the patient forgets what they ate." She added that the parasite "exists in the environment and can contaminate food at any time during harvesting or growing or poor sanitation during agricultural methods."
Melanie Firestone, a foodborne illness researcher at the University of Minnesota, told the Associated Press that Cyclospora is frequently underreported because many standard food poisoning tests are not designed to detect it. She also explained that contaminated foods can be common ingredients in multiple recipes, making it difficult to establish a single shared exposure source.
What the Evidence Shows — and What It Does Not
Cyclospora cayetanensis is a well-characterized parasitic pathogen that spreads when people consume food or water contaminated with feces containing the parasite. It is not spread person-to-person.
The current Michigan outbreak is confirmed by laboratory testing. However, investigators have not yet linked the cases to a single food item, farm, supplier, or distribution chain. Michigan's MDHHS maintains a dedicated cyclosporiasis outbreak webpage updated daily.
Who Faces the Greatest Risk?
Cyclospora can infect anyone who consumes contaminated food or water. However, some groups may experience more severe illness or a longer recovery:
- People with weakened immune systems, including those with HIV/AIDS, cancer patients on chemotherapy, and transplant recipients
- Older adults, who may have more difficulty tolerating prolonged diarrhea and dehydration
- Young children, who are more vulnerable to dehydration from frequent watery stools
- People in the southeast Michigan counties where case density is highest
- Those who regularly eat fresh, uncooked produce — including salads, fresh herbs, and fruit — that has not been thoroughly washed
Symptoms and Warning Signs to Watch For
According to MDHHS and the CDC, symptoms typically appear two to 14 days after exposure and may include: frequent, watery diarrhea; loss of appetite and unintended weight loss; abdominal cramps and bloating; nausea (vomiting is less common); low-grade fever; and fatigue and body aches.
Important: These symptoms do not resolve without antibiotic treatment. If symptoms last more than a few days and do not improve on their own, contact a health care provider. Tell your doctor you may have been exposed to Cyclospora or consumed fresh produce recently.
Seek urgent medical attention if diarrhea is accompanied by severe dehydration, high fever, confusion, or bloody stools.
What You Can Do Now
The MDHHS and Michigan Department of Agriculture and Rural Development have issued guidance for residents, restaurants, and commercial kitchens:
- Lettuce/leafy greens : Buy whole heads of lettuce rather than pre-washed bagged salad mixes or salad kits, and discard the outer two to three layers of leaves before washing the inner leaves under running water.
- Cilantro and basil : Wash thoroughly under running water, separating the leaves. Safest when cooked.
- Green onions : Trim the root end and remove the outer layer, then wash thoroughly under running water. Safest when cooked.
- Snow peas : Wash under running water and rub the surface.
- Raspberries : Particularly difficult to clean because the parasite can hide in the bumpy surface. Safest when cooked as part of pies or jams.
- All fresh produce : Wash under clean running water, even if you plan to peel it. Cook food to 158°F or higher to kill Cyclospora.
- Wash and sanitize all cutting boards, surfaces, and utensils before and after handling fresh produce.
If you develop sudden diarrhea that lasts more than a few days, contact your health care provider and ask to be tested for Cyclospora. Tell your provider about any fresh produce you have eaten in the past two weeks.
Cost and Access: What Patients Should Know
Cyclospora is diagnosed through stool testing. Ask your health care provider specifically to test for Cyclospora — general stool panels may not detect it automatically.
The standard antibiotic treatment for cyclosporiasis is trimethoprim-sulfamethoxazole (TMP-SMX), which is widely available as a generic medication and is covered by most insurance plans and Medicare. For uninsured patients, low-cost community health centers and county health departments can assist with testing referrals and treatment access.
What Happens Next
The MDHHS and state and local public health officials continue to interview confirmed cases in an effort to identify a common food exposure. The CDC's dedicated cyclosporiasis surveillance page is updated regularly. Investigations of this type can take weeks or months, and some outbreaks never yield a confirmed source.
MedicalDaily will update this story as new case counts, source identification, or recall information become available.
The Bottom Line
The Michigan Cyclospora outbreak has reached 992 confirmed cases — nearly 20 times the state's annual baseline — in just two weeks. With no source yet identified, consumers in Michigan and neighboring states should be aware of the symptoms, exercise extra caution when handling fresh produce, and seek medical attention promptly if diarrhea persists. This is a treatable illness — but treatment requires a prescription, and the infection will not clear on its own.
