Cyclospora outbreak rises in Kentucky as summer cases spread nationwide

Norton Healthcare diagnosed 10 adults with cyclosporiasis in its facilities over the previous two weeks as of July 8, and none of the patients had been hospitalized. The Kentucky cluster comes as hospitals and health departments across the country track a parasite that tends to surge in summer and can move quickly through contaminated food before investigators identify the source.

From May 1 through June 16, the CDC counted 145 U.S.-acquired cases of cyclosporiasis, with 20 hospitalizations and no deaths. U.S. cases usually peak between May and August, a pattern that fits the summer rise now showing up in Kentucky, Michigan, Virginia and Maryland. Cyclosporiasis is caused by the microscopic parasite Cyclospora cayetanensis.

The disease is difficult to track because infection starts when people ingest food or water contaminated with stool, and the symptoms can take time to surface. Illness usually begins about a week after exposure, but it can start as soon as two days later or as late as two weeks or more. That lag gives contaminated produce time to move through farms, distributors, grocery shelves and kitchens before a common source is obvious, especially when cases appear in several states at once.

Public-health officials have not identified the food source of the 2026 outbreak yet. Prior U.S. cyclospora outbreaks have often been tied to fresh produce. Cyclosporiasis is a nationally notifiable disease, and cases are tracked year-round to spot common-source outbreaks sooner. Kentucky’s reportable-disease rules also require prompt notification of suspected outbreaks.

Most healthy people eventually recover without treatment, though the illness can linger. Trimethoprim-sulfamethoxazole, sold as Bactrim, Septra and Cotrim, is the treatment of choice, and there is no vaccine. Prevention comes down to avoiding food or water contaminated with feces, because routine washing or sanitizing is unlikely to kill Cyclospora on produce once it is there.