Michigan state health authorities report investigating a large and growing outbreak of cyclosporiasis, a diarrheal illness.
As of Tuesday, June 30, more than 170 cases have been reported in Monroe, Lenawee, Washtenaw, Wayne, Livingston, Shiawassee and Jackson counties in the past nine days. Typically, Michigan only identifies around 50 cyclosporiasis cases per year.
Current case county by county as of Tuesday, June 30:
Monroe: 70
Lenawee: 33
Washtenaw: 21
Wayne: 12
Jackson: 7
Shiawassee: 7
24 cases in 11 other counties and the City of Detroit.
Cyclosporiasis is caused by infection with the parasite Cyclospora cayatenensis, which is commonly found in developing countries and spread by food or water contaminated with feces. In recent years, outbreaks have occurred in the U.S. as a result of eating contaminated fresh produce, especially during the summer months. Cyclosporiasis is not known to spread from person to person. Symptoms occur two to 14 days after exposure and may include:
Frequent watery diarrhea.
Loss of appetite and weight.
Abdominal cramps and bloating.
Nausea (vomiting is less common).
Low-grade fever.
Alpha-gal syndrome, or Red Meat Allergy
Individuals experiencing sudden gastrointestinal illness are encouraged to be evaluated by a health care provider. Symptoms of cyclosporiasis can be significantly improved with antibiotic treatment. If untreated, the illness may last for a few days to a month or longer. Providers are urged to consider cyclosporiasis among patients presenting with acute gastrointestinal illness in southeast Michigan.
The Centers for Disease Control and Prevention (CDC) reported as of June 16, 2026, 145 cases were reported in people who acquired cyclosporiasis from 17 states.