A parasitic infection known as cyclosporiasis is spreading rapidly across the United States, resulting in hundreds of illnesses that health authorities are working to monitor. Caused by the parasite Cyclospora cayetanensis, the condition is typically contracted through the consumption of contaminated food or water. While the infection is rarely fatal, it is characterized by unpleasant gastrointestinal distress, most notably frequent and watery or “explosive” diarrhea, alongside nausea and vomiting.
According to the Centers for Disease Control and Prevention (CDC), the current “season” for this illness, which typically sees a spike in infections, began on May 1 and is expected to continue through August. Here’s what to know since the CDC’s last update on June 16, which reflected only 145 cases nationwide in 18 states. As of July 9, the CDC reported 843 confirmed domestic cases across 31 states, with patients ranging in age from 5 to 88 and a median age of 44. Of these individuals, 86 required hospitalization, though no deaths have been reported. Additionally, 343 cases have been linked to international travel.
There is a notable discrepancy between CDC data and reports from individual states, largely because the federal agency only counts laboratory-confirmed cases that are domestically acquired and occurred on or after May 1. For instance, while the CDC reported between 161 and 300 cases in Michigan as of July 9, state health officials reported 700 total cases to USA TODAY as of July 6. The CDC is currently aware of more than 1,500 additional cases that require further analysis to confirm their origin. Because of the rapid rise in numbers, the agency plans to transition from monthly to weekly state data reporting.
State-level reporting highlights the scale of the outbreak. Ohio officials recorded 364 cases, nearly all of which were domestically acquired, with 46 hospitalizations. North Carolina reported 205 cases between May 1 and July 9, while New York City documented 301 cases by July 7, with 273 occurring since May 1. New York State confirmed another 120 cases in the same timeframe.
Cyclosporiasis is transmitted via the fecal-oral route. Spikes in infections are common during the summer months when fresh produce like basil, lettuce, and raspberries can become contaminated. Symptoms typically manifest about a week after exposure, though they can appear within two days or up to two weeks later. While many healthy individuals recover at home without medical intervention, the infection can persist for months or recur if left untreated. Health officials emphasize that children, the elderly, and those with compromised immune systems are at a higher risk of severe illness and should seek professional care if symptoms arise.
Cyclosporiasis is transmitted via a fecal-oral route, meaning contact with foods, drinks and surfaces contaminated with infected poop particles. Usually, this means consuming the affected food or drink directly, or touching something contaminated and then touching your mouth without washing your hands.
To prevent catching cyclosporiasis in the first place, the CDC, Cleveland Clinic and Michigan Health Department suggest that you:
