Check Latest Cyclosporiasis Cases in Your County

An intestinal illness known as cyclosporiasis, which can lead to weeks of severe and “explosive” diarrhea, is spreading across the United States at a rate that health officials describe as unusually high for this time of year. Thousands of cases have already been reported nationwide, and the total number continues to rise.

While most states have not yet released county-level data, USA TODAY has gathered information directly from state health departments to identify where reported cyclosporiasis cases are concentrated and which communities have been most affected.

Michigan

Michigan has reported more cyclosporiasis cases than any other state in the nation. As of July 15, the state had recorded over 3,700 cases and 44 hospitalizations, according to the Michigan Department of Health and Human Services.

At the county level, Wayne County reported the most cases, with 339, followed by Washtenaw and Monroe counties, based on data available through July 13. However, when population size is taken into account, Shiawassee County is the hardest-hit, with about 307 cases per 100,000 residents. That’s nearly double the rate reported in Monroe and Lenawee counties, which each had about 165 cases per 100,000 residents.

Ohio

Ohio is another state that reported a record-high number of cyclosporiasis cases. Based on the latest data available through July 9, the state confirmed 264 cases. Lucas County reported the highest number of cases with 86, followed by Wood County with 49 and Wyandot County with 23. Wyandot County had the state’s highest infection rate at about 107 cases per 100,000 residents, followed by Carroll County and Wood County.

Kentucky

Kentucky also experienced an unusual spike in cyclosporiasis cases. It is one of four states, including Michigan, Ohio, and West Virginia, where the CDC believes a cluster of cases is likely linked as it investigates a nationwide surge in infections.

“While cases of cyclosporiasis normally rise in the spring and summer months, Kentucky is one of many states experiencing a larger-than-typical increase,” said Beth Fisher, spokesperson at the Kentucky Cabinet for Health and Family Services.

“In 2026, the Kentucky Department for Public Health has received 100 reports of cases of cyclosporiasis, and 55 cases have been confirmed, whereas Kentucky typically only has about 35 cases of cyclosporiasis each year.”

Connecticut

As of July 13, Connecticut confirmed 35 cyclosporiasis cases in 2026, nearly double the count from this time last year. Health officials are investigating outbreaks in several states and have not yet identified a source for the illnesses.