US sees surge in cyclosporiasis cases linked to fresh produce
More than 3,700 cases of the parasite-caused illness have been reported in Michigan, with hundreds of additional infections across other states, prompting health officials to advise thorough washing and cooking of fresh fruits and vegetables.
The United States is experiencing a sharp increase in cyclosporiasis, a diarrheal illness caused by the parasite Cyclospora. Michigan's health department reported 3,762 cases as of July 15, up from 1,500 a week earlier, and 44 hospitalizations. Ohio has recorded at least 364 infections, and nearly every state has reported at least one case this year.
Cyclosporiasis is transmitted through consumption of contaminated fresh produce such as bagged salads, basil, cilantro, peas and berries. The parasite does not spread from person to person. Symptoms include frequent watery diarrhea, abdominal cramping, nausea and vomiting, typically appearing two days to two weeks after exposure. While rarely fatal, the illness can last for weeks without treatment, especially in immunocompromised individuals.
"At this time, no specific produce grower, supplier, or type of produce has been identified as the source," said Laina Stebbins, spokesperson for the Michigan Department of Health and Human Services. State officials suspect lettuce or bagged salad products but have not pinpointed particular brands.
Experts note that tracing the source is difficult because contamination can occur in distant growing regions and the lag between exposure and symptom onset hampers investigations. Dr. Kathleen Linder, an epidemiologist at the Veterans Affairs hospital in Ann Arbor, explained that globalized food distribution increases the chances of such pathogens entering the supply chain.
Public health agencies recommend cooking produce when possible, as heat effectively destroys the parasite, and washing raw fruits, vegetables and herbs thoroughly under running water. Even pre-washed packaged items should be rinsed again. Consumers are advised to avoid damaged produce, consider buying whole heads of lettuce instead of pre-cut salads, and refrigerate leftovers within two hours.
People experiencing severe diarrhea should stay hydrated and seek medical care if they develop signs of dehydration such as dizziness, inability to retain fluids, or dark urine. The Centers for Disease Control and Prevention is coordinating with state health departments, though reduced staffing has slowed data collection.
The outbreak underscores the need for improved surveillance of foodborne pathogens and reinforces basic food-handling practices to reduce risk.