Federal regulators have closed their investigation into the largest cyclosporiasis outbreak in U.S. history, which sickened nearly 13,000 people and led to two deaths. While officials confirmed the parasite was present at Mexican farm and processing sites tied to shredded iceberg lettuce, the root cause of the contamination remains undetermined.
FDA Closes Investigation After Finding Cyclospora at Mexican Production Sites
The U.S. Food and Drug Administration closed its investigation into the multi-state parasite surge after inspectors collected environmental samples during onsite visits to Taylor Farms de Mexico facilities. The sweep yielded two positive samples of the parasite cyclospora: one extracted from a tank holding outgoing wastewater at the company’s processing facility, and another taken from a drainage ditch at an iceberg lettuce grower.
Inspectors were dispatched to Guanajuato, Mexico, in August following a steep decline in international food safety inspections after the COVID-19 pandemic. The field visit marked the agency’s first inspection at the site in more than seven years. These steps include enhancing laboratory capacity in Mexico to collect, analyze, and process samples for Cyclospora investigations in-country, which helps reduce the time needed to get final laboratory analyses. Taking lessons learned from the investigation and any root cause analysis of this specific outbreak, the agency aims to update the Cyclospora Prevention, Response and Research Action Plan with longer-term prevention, response, research, and programmatic activities to lay the groundwork for stronger prevention and response in future growing seasons ahead of 2027.
The agency added that these findings provide strong epidemiological data and traceback convergence supporting the link between the outbreak and recalled products.
Human Toll and Scale of the Multi-State Outbreak
The outbreak, which emerged in early summer, sickened 12,883 people across 21 states, hospitalized at least 570, and resulted in two deaths in Michigan. Federal health officials noted that thousands of additional infections were reported during the peak of the crisis, though health authorities faced difficulties in definitively tying many of those illnesses to the recalled produce.
At the height of the contamination event, more than 1,000 infections occurred in a single day before voluntary recalls took effect. The Centers for Disease Control and Prevention officially declared the outbreak over on September 11.
Investigators traced the contamination to shredded iceberg lettuce supplied to Taco Bell restaurants and sourced from central Mexico. In mid-July, Taylor Farms de Mexico issued a voluntary recall affecting iceberg lettuce distributed to 27 states with best-if-used-by dates up to August 3. Taco Bell confirmed it is no longer using lettuce from Taylor Farms de Mexico at any of its restaurants.
Taylor Fresh Foods Closes Facility and Cuts Supplier
Parent company Taylor Fresh Foods addressed the regulatory findings by noting that the independent grower linked to the positive drainage ditch sample is no longer part of its supplier program.
A company spokesperson emphasized that the positive sample taken from the wastewater tank came from discharged waste and sewer water outside the processing plant. The company also maintained that current evidence remains insufficient to connect the environmental sample results to ongoing genetic comparisons of clinical specimens.
FDA Outlines Ten-Point Action Plan Ahead of the 2027 Growing Season
With the investigation concluded, the FDA has released a 10-point prevention plan aimed at keeping the parasite from disrupting future growing seasons.
The agency is also collaborating with Mexican authorities, including the Ministry of Agriculture and the Federal Commission for the Protection Against Sanitary Risks, to ensure imported fresh produce meets U.S. safety standards ahead of 2027.
