The number of reported cyclosporiasis cases in the United States has reached an estimated 22,700 nationwide, marking a substantial surge with thousands of new cases confirmed in recent weeks. The Centers for Disease Control and Prevention (CDC) reported 10,468 lab-confirmed cases across 47 states as of Tuesday, an increase of 6,707 from the previous week. An additional 12,255 reports are pending laboratory confirmation and investigation, contributing to the overall estimated toll.
Two deaths have been attributed to the parasite in Michigan, and 517 individuals have been hospitalized across the country. Michigan and Ohio are currently at the epicenter of the outbreak, with local health departments in these states reporting over 15,000 cases and more than 300 hospitalizations combined. A lag often exists between data reported at the local level and federal confirmation.
Cyclosporiasis is caused by the parasite Cyclospora and is typically spread through the consumption of food or water contaminated with human feces. Symptoms can include severe diarrhea, abdominal cramps, and vomiting. While the illness usually resolves within two weeks and is rarely fatal, it can lead to severe dehydration.
The current outbreak has been linked to shredded iceberg lettuce from Taylor Farms, distributed to various retailers including Taco Bell. In North Carolina, health officials are investigating lettuce, cilantro, and parsley as potential sources. Michigan health officials, while not identifying a specific source, have advised residents to thoroughly wash and trim produce such as lettuce, leafy greens, cilantro, basil, green onions, raspberries, and snow peas before consumption.
Across the U.S., patients diagnosed with cyclosporiasis range in age from one to 98 years, with a median age of 44. Females represent 56 percent of reported cases. The majority of patients fell ill around July 4.
This outbreak significantly surpasses the largest previous recorded outbreak in 2019, which involved 4,703 cases, primarily linked to imported basil. Typically, the U.S. sees only a few hundred cyclosporiasis cases annually, often associated with travelers returning from endemic regions in Mexico, Central America, South America, and the Caribbean. Contamination of fresh produce can occur when it is washed or irrigated with water containing human sewage.
Experts note that Cyclospora infections can cause prolonged or recurring symptoms, unlike more common foodborne illnesses. Treatment for cyclosporiasis involves the antibiotic trimethoprim-sulfamethoxazole. Medical professionals recommend seeking testing for Cyclospora if diarrhea persists for more than a few days, as it is not a standard test.
Currently, health officials are monitoring six distinct outbreaks of cyclosporiasis. While these are tracked separately, experts suggest they may not represent entirely unrelated events and highlight the ongoing challenge of identifying common food sources for each cluster of infections.