CDC probes Cyclospora outbreak with over 400 cases across 18 states

Michigan reports over 300 cases in ‘large and growing’ outbreak

The CDC said it is working with the U.S. Food and Drug Administration and local health officials to investigate clusters of Cyclospora cases in several states. Those who became ill ate food in the U.S. and had not reported any travel in the two weeks before becoming sick, according to the agency.

Between May 1 and June 16, at least 145 cases of cyclosporiasis were reported across 17 states, the CDC said. Of those, 20 resulted in hospitalization. New York has seen 107 cases since May 1, according to the New York State Department of Health.

Outside the time frame of the CDC’s count, Michigan health officials have been investigating an unusually high number of cases in what they described as a “large and growing outbreak.” More than 300 cases had been reported since June 22 as of Friday, in a state that typically identifies only about 50 cases of cyclosporiasis annually, according to the Michigan Department of Health and Human Services.

The illness is caused by the parasite Cyclospora cayetanensis, which spreads through raw produce and water contaminated with human feces. It typically causes the intestinal illness cyclosporiasis, whose symptoms include watery diarrhea, cramps, nausea, fatigue, loss of appetite, low-grade fever, and vomiting. The CDC said the most commonly reported symptom is “watery diarrhea with frequent and sometimes explosive bowel movements.”

Cyclosporiasis is not usually life-threatening, and most people with healthy immune systems recover on their own in days or weeks, the agency said. In more severe cases, the infection is typically treated with antibiotics.

In the U.S., the illness is seasonal, with cases usually peaking between May and August. During the spring and summer, people typically eat a lot of fresh produce such as basil, cilantro, spinach, and berries, which have been linked to past outbreaks. The U.S. typically sees several hundred cases of cyclosporiasis annually. In 2019, an unusually high 4,703 infections were identified, according to a 2023 CDC report.

It can take anywhere from two days to two weeks after ingesting the parasite to develop symptoms, the CDC said. Not everyone infected experiences symptoms. The disease is not typically transmitted from person to person.

The CDC advises people to wash all fresh produce thoroughly before eating, and to wash hands and kitchen surfaces thoroughly. Anyone with symptoms of cyclosporiasis should see a healthcare provider and, if they test positive, report it to their local health department. Those who are ill should drink plenty of water and other fluids to avoid dehydration.