Largest U.S. Cyclospora Outbreak Linked to Recalled Lettuce

By Scout Nelson

Health officials continue to investigate what is being described as the largest cyclospora outbreak ever recorded in the United States, with thousands of people reporting illnesses linked to the parasite. Cyclospora causes cyclosporiasis, a gastrointestinal illness that is typically spread through food or water contaminated with human feces.

Federal investigators have connected part of the outbreak to Taylor Farms iceberg lettuce sourced from central Mexico. The lettuce was supplied to retailers and restaurants, leading the company to issue a voluntary recall while authorities continue to trace the source and extent of the contamination.

Food safety experts believe contaminated irrigation or contact water is the most likely pathway through which the parasite entered produce fields. Water used for irrigation or pesticide application can carry harmful pathogens that contaminate crops before they are harvested.

Although cyclospora cases have previously been reported in the United States, the scale of the current outbreak is unprecedented. Researchers know humans are the host for the parasite, but determining the exact food source responsible for widespread infections remains a difficult and time-consuming process.

The Centers for Disease Control and Prevention (CDC) is investigating cases across multiple states. More than 6,000 confirmed infections have been reported since May, while thousands of additional cases identified by state and local health departments are still under review. Michigan has reported one of the highest numbers of cases.

Investigators face several challenges, including delayed symptom onset, limited testing capabilities, and the complexity of tracing produce through modern supply chains. Fresh produce can pass through multiple farms, distributors, and processing facilities before reaching consumers, making contamination sources difficult to identify.

Despite the outbreak, food safety specialists emphasize that fruits and vegetables remain an important part of a healthy diet. Consumers are encouraged to stay informed about recalls, follow proper food-handling practices, and monitor public health advisories.

Experts also recommend practicing good hygiene, including handwashing and proper produce handling. While consumers should avoid recalled products, health officials stress that most fresh produce remains safe to eat and should continue to be included in a balanced diet.

Photo Credit: commons-jeremy-bronson