ATLANTA — The U.S. Centers for Disease Control and Prevention is investigating clusters of cyclosporiasis cases linked to a parasitic infection that can cause prolonged watery diarrhea, as health officials reported 145 domestically acquired infections across 17 states.
The cases, reported in people who became ill between May 1 and June 16, 2026, involved no recent international travel, according to CDC surveillance data. About 20 people have been hospitalized. No deaths have been reported.
Cyclosporiasis is caused by the microscopic parasite *Cyclospora cayetanensis*, which spreads through food or water contaminated with feces. Symptoms typically begin about one week after ingestion and can include watery diarrhea — sometimes described as explosive — along with loss of appetite, fatigue, bloating, stomach cramps, nausea and vomiting. The illness can last weeks to months if untreated, though many people recover without specific therapy.
New York reported the highest number of cases, between 31 and 80. Illinois and Texas each reported 11 to 30 cases. Other affected states with 1 to 10 cases each include Alaska, Colorado, Connecticut, Florida, Georgia, Louisiana, Massachusetts, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia and Wisconsin.
The CDC noted there is currently no evidence of a single multistate outbreak linking all cases. Instead, the figures represent a surveillance total that includes several clusters under investigation. Local, state and federal officials, including the Food and Drug Administration, continue traceback efforts to identify potential sources, which often involve fresh produce such as herbs, berries or leafy greens.
Separately, Michigan health authorities reported a sharp rise in cases not yet fully reflected in national totals. More than 170 cases were identified in southeast Michigan as of late June, concentrated in counties including Monroe, Lenawee and Washtenaw.
Health officials recommend thorough washing of fresh produce, though the parasite can be difficult to remove. Cooking produce kills the parasite. People experiencing prolonged diarrhea should consult a healthcare provider for testing and possible antibiotic treatment.
Case counts typically rise during the spring and summer months. The CDC continues to monitor the situation and update data as investigations proceed.
