A parasitic illness that causes explosive, relentless diarrhea has reached an unprecedented scale across the United States this summer. As of July 8, 2026, at least 718 cases of cyclosporiasis have been reported in Michigan since June 22 — a number roughly 14 times higher than the state normally records in an entire year. Ohio has confirmed at least 177 cases since late June. New York has recorded 120 cases since May 1, North Carolina reported at least 110 cases since May, Illinois has seen 141 cases, and Indiana has reported 72 cases. No common food source has been identified. No recall has been issued.
Health departments in multiple states are urging residents who have experienced prolonged or relapsing diarrhea since late May to contact their physician and specifically request a Cyclospora PCR or modified acid-fast stain stool test. The parasite does not appear on standard stool panels and is frequently missed without a targeted order.
Why This Matters
Cyclosporiasis caused by the microscopic parasite Cyclospora cayetanensis is not a typical 24-hour stomach bug. Unlike norovirus, which usually runs its course within a few days, cyclosporiasis symptoms can last for weeks and return in waves after appearing to resolve. Anyone who has had persistent diarrhea lasting longer than five to seven days since late May — especially those in Michigan, Ohio, Indiana, Illinois, New York, or North Carolina — should not assume it is a routine stomach bug.
The infected range in age from 5 to 86 years old, and there have been at least 20 hospitalizations nationally, though no deaths have been reported so far. The true number of people infected is almost certainly higher than what is captured in official counts, because the illness requires a specific stool test that is not included in routine screening.
For immunocompromised individuals — including people on chemotherapy, organ transplant recipients, older adults, and infants — the risk of prolonged illness and complications is significantly elevated.
What We Know So Far
Since June 22, at least 718 cases of cyclosporiasis have been reported across at least eight counties in Michigan: Monroe, Lenawee, Washtenaw, Wayne, Shiawassee, Jackson, Oakland, and Livingston. No specific food, grower, or supplier has been identified as the source so far, according to the Michigan Department of Health and Human Services.
As of July 2, the Ohio Department of Health reported at least 177 cyclosporiasis cases in 2026 — of those, 171 occurred since late June. The Illinois Department of Health has seen 141 cases this year, a "higher than average" number, with no single potential cause identified. New York State recorded 120 cases since May 1, according to a July 7 statement from the state health department — though the spokesperson noted this is not unusually high for New York, which typically records 500-700 cases per year. As of July 6, North Carolina reported at least 110 cyclospora infections since May. Indiana reported 72 cases since May 1.
The CDC has received reports of 145 cases of cyclosporiasis acquired in the United States in the period from May 1, 2026, through June 16, 2026. There is currently no evidence of a single, multistate Cyclospora outbreak linking all cases. Investigators at the CDC and FDA are conducting ongoing traceback investigations.
Dr. Brian Kaminski, vice president of medical affairs at ProMedica Health System — treating patients in southeast Michigan and northwest Ohio — described cases in the two states as appearing to be part of an "epidemic cluster." As of last reporting, ProMedica had accounted for 411 of the confirmed Michigan cases.
Where the Risk Is Highest
The outbreak is concentrated in eight southeast Michigan counties — Monroe, Lenawee, Washtenaw, Wayne, Shiawassee, Jackson, Oakland, and Livingston — and has spread into Ohio, with cases confirmed across 43 counties statewide there.
Within Michigan, Wayne County — which includes Detroit — is among the hardest-hit areas. States with reported cases in the national CDC surveillance dataset include Massachusetts, Florida, Indiana, Wisconsin, Ohio, Pennsylvania, North Carolina, Virginia, Tennessee, Texas, Georgia, Colorado, Illinois, New York, New Jersey, Connecticut, and Alaska.
Produce Safety: What the Evidence Shows Right Now
No specific food source has been identified in the current outbreak. However, based on the pattern of prior Cyclospora outbreaks, health officials have identified the categories of fresh produce most likely to be implicated.
Previous outbreaks have involved raspberries, bagged lettuce or salads, cilantro, and basil. Rinsing produce can reduce the risk for cyclosporiasis but does not eliminate it. "The parasite 'clings to produce,'" Dr. Kaminski told NBC News. "Raspberries in particular can be difficult to clean because they are covered in tiny hairs that the parasite likes to hang on."
The Michigan Department of Health and Human Services advises that cooking food to 158°F or higher will kill Cyclospora. Michigan health officials are also encouraging consumers to buy whole heads of lettuce rather than pre-cut mixes, and to remove outer leaves and wash the remaining head under running water before eating.
What Doctors and Experts Say
Dr. Natasha Bagdasarian, MDHHS chief medical executive, described the confirmed case count as a "moving target," meaning that cases are likely to continue rising.
Dr. Irfan Hafiz, an infectious disease physician at Northwestern Medicine, explained why Cyclospora is so frequently misdiagnosed: "The symptoms are a bit less, but they go on longer. Noroviruses kind of hit you hard and then it's done. This kind of just drags on for a longer period of time."
Symptoms and Warning Signs to Watch For
The primary symptom of cyclosporiasis is watery, explosive diarrhea that may come in waves and return after appearing to resolve. Additional symptoms may include severe stomach cramps and bloating, nausea and vomiting, loss of appetite, significant fatigue, unexplained weight loss, low-grade fever, and muscle aches.
It takes anywhere from two to 14 days after ingesting the Cyclospora parasite to show signs of illness. The illness can last from a few days to over a month, and symptoms frequently relapse.
What You Can Do Now
- Request the right test. If you have had prolonged or relapsing diarrhea since late May in any affected state, ask your physician specifically for a Cyclospora PCR or modified acid-fast stain stool test. Standard stool panels do not detect this parasite.
- Handle produce carefully. Wash all fresh produce under clean running water. For raspberries, cilantro, basil, and bagged salad mixes, cook when possible. The only guaranteed decontamination method is cooking to 158°F.
- Choose whole over pre-cut. Buy whole heads of lettuce and remove outer leaves rather than purchasing pre-cut mixes.
- Wash hands thoroughly. Wash hands with soap and water before and after handling raw produce.
- Check your state health department. Residents in Michigan, Ohio, Indiana, Illinois, New York, and North Carolina should check their state health department website for updated case counts and guidance.
Cost and Access: What Patients Should Know
Cyclosporiasis is typically treated with the antibiotic trimethoprim-sulfamethoxazole, which is available at most pharmacies, often at low cost with insurance. Stool testing for Cyclospora requires a specific laboratory order; if a standard stool panel was ordered and came back negative, that does not rule out Cyclospora infection.
What Happens Next
The CDC and FDA are conducting active traceback investigations in multiple states. If a contaminated food source is identified, a recall will be issued. MedicalDaily will update coverage as new information becomes available.
The Bottom Line
The Cyclospora outbreak now affecting Michigan, Ohio, Indiana, Illinois, New York, North Carolina, and other states is real, expanding, and unlike typical summer stomach bugs. The illness lasts longer, relapses more often, and requires a specific test to diagnose. No food recall has been issued because no source has yet been confirmed. Until investigators identify a vehicle, residents in affected states should handle fresh produce with extra care, request the right stool test if they develop prolonged gastrointestinal symptoms, and ensure that immunocompromised or elderly family members get timely medical evaluation.
