FDA and CDC expand cyclospora investigation tied to iceberg lettuce to 20 states

Federal health agencies said Thursday they have expanded an investigation into a cyclospora outbreak tied to iceberg lettuce, with confirmed cyclosporiasis cases reported in 20 states. The Food and Drug Administration and the Centers for Disease Control and Prevention said the scope of the investigation increased after lab-confirmed cases were identified in three additional states.

The agencies reported that the additional states were Texas, Georgia, and Tennessee, bringing the confirmed total to 20 states. The agencies described the outbreak as the largest of its kind in U.S. history, with the number of identified cases continuing to grow as monitoring expands.

Officials’ updated tally reflects a wider national public health effort to detect and confirm infections, determine whether a common food source is involved, and coordinate information with state and local health departments. Because food products move through multiple supply channels, federal and state officials said the geographic spread is one reason the probe relies on consistent case confirmation and timely reporting across jurisdictions.

The outbreak has also put regulatory and food-safety oversight at the center of federal-state coordination. The FDA and CDC said the illness is linked to iceberg lettuce, underscoring the role of federal agencies in tracing contaminated commodities through production and distribution, while states handle local case investigation, reporting, and outreach.

While the agencies’ announcement focused on widening the confirmed case footprint, it also indicated that surveillance remains active. As new states report lab-confirmed cyclosporiasis cases, officials can refine the epidemiological picture, including which exposure routes are most consistent with the timing and characteristics of the illnesses.

Public health officials said cyclospora infection is caused by the parasite Cyclospora cayetanensis and can cause prolonged gastrointestinal illness. The agencies’ continued emphasis on confirmed cases in additional states is part of a broader effort to ensure clinicians and public health responders are aware of the expanding geographic pattern.

The next steps for the investigation, according to Thursday’s update, will depend on continued case confirmations and information that supports links to specific food supply channels. Federal officials said the widening investigation also helps guide how states prioritize testing, reporting, and communications to reduce further exposure while investigators work to identify the source and reduce risk.