Federal and state health officials are investigating an increasing number of cyclosporiasis cases, a parasitic infection causing severe gastrointestinal distress. As of June 18, the Centers for Disease Control and Prevention (CDC) reported 145 suspected cases in 17 states, with 20 individuals requiring hospitalization. These illnesses occurred between May 1 and June 6.
More recent data from Michigan indicates a significant surge, with state health officials reporting over 150 cases in that state alone since June 22. More than a dozen Michigan residents have been hospitalized due to the infection. Officials are working to pinpoint a common exposure in Michigan, where the first case was identified on June 22.
Cyclosporiasis is caused by the cyclospora parasite and leads to symptoms such as diarrhea, severe cramping, nausea, vomiting, and fatigue. These symptoms typically appear about a week after exposure. Human-to-human transmission of the parasite is considered rare.
Authorities suspect a foodborne source for the current outbreak, as patients have not reported recent travel that might explain the widespread illnesses. Previous outbreaks of cyclosporiasis have been linked to produce like bagged salad kits, cilantro, and basil. The CDC, in coordination with the Food and Drug Administration (FDA), is conducting interviews with patients to identify potential sources.
While New York has reported the highest number of cases among the states tracked by the CDC's June 18 report (between 31 and 80), the situation in Michigan appears to have rapidly escalated since that data was compiled. Texas and Illinois have reported the second-highest numbers, with 11 to 30 cases each. The remaining states with reported cases have between one and ten each.
Health authorities emphasize that undiagnosed cases may exist, as not everyone infected with the parasite seeks testing or treatment. Cyclosporiasis can persist for over a month, with symptoms potentially subsiding and recurring. The CDC recommends that individuals concerned about gastrointestinal illness consult a healthcare provider and practice good hydration, especially during high temperatures.
To prevent cyclosporiasis, the CDC advises avoiding food and water at risk of fecal contamination and adhering to general food safety practices. Treatment typically involves a course of the antibiotic trimethoprim-sulfamethoxazole. Most individuals with healthy immune systems recover without medical intervention.
Cyclosporiasis cases often see an increase between May and August. Historically, the infection is more common in individuals returning from international travel, but this does not appear to be a factor in the current domestic outbreak. Separately, 45 cases of cyclosporiasis have been reported in individuals who became ill after consuming food or water while traveling outside the U.S. These cases range in age from 17 to 89, with three hospitalizations and no reported deaths. The travel destinations for these patients were not specified.