FDA detects cyclospora at Mexican farm tied to 12,883 US lettuce illnesses

Environmental findings in Guanajuato

The US Food and Drug Administration concluded its inquiry on Friday after detecting cyclospora at a Mexican facility and an associated farm. Investigators identified the microscopic parasite in two locations: outgoing wastewater from a Taylor Farms processing plant and sediment from an agricultural drainage ditch. The implicated cultivation site is operated by an independent grower in Guanajuato that supplied fresh iceberg lettuce to the company. While the agency determined that the parasite existed in the cultivation environment, it could not identify the specific pathway through which sewage or contaminated water reached the crop. The visit marked the first FDA inspection at the location in more than seven years, following a prolonged reduction in foreign food safety reviews after the COVID-19 pandemic.

Scope of the multi-state outbreak

The contamination produced 12,883 documented illnesses between July and September, making it the largest cyclosporiasis event recorded in the United States. Federal health data recorded 570 hospitalizations and two deaths across 21 states. Patients experienced severe gastrointestinal symptoms, including watery diarrhea, stomach cramps, increased digestive gas, bloating, and rapid weight loss. Initial clusters centered in four Midwestern states before surveillance expanded nationwide. Health investigators in Michigan originally connected patient clusters to shredded lettuce distributed to Taco Bell locations. Taylor Farms subsequently recalled 236,192 cases of iceberg lettuce that had entered commercial supply chains for restaurants, retailers, and food service distributors, including Walmart, Subway, Jack in the Box, and Sysco.

Testing disputes and corporate response

Taylor Farms stated that the contaminated drainage ditch belonged to an independent grower who has been permanently excluded from its supplier program. The company noted that its processing operations in central Mexico remain suspended while technicians develop updated sanitation measures across the production chain.

Our facility remains closed in central Mexico as we work with our research team to implement enhanced safety protocols from the field to the facility.

The federal findings follow conflicting test results released during the summer. Mexican health authorities in the Secretariat of Health reported negative results from their own lettuce and water samples in August. That announcement came days after the FDA was forced to retract an earlier border test that had falsely identified cyclospora in a Mexican lettuce consignment. On 16 July, Mexico's National Epidemiological Surveillance System had issued a travel advisory regarding foodborne illness risks in the United States.

Scientific hurdles and regulatory closure

The Centers for Disease Control and Prevention declared the multi-state outbreak officially over on 11 September. Federal scientists continue genetic evaluations on the collected samples, though direct strain matching remains technically difficult. Unlike common bacterial pathogens such as salmonella or E. coli, cyclospora cannot be cultured in laboratory media, preventing researchers from rapidly matching patient specimens to environmental isolates. The FDA stated that traceback records and epidemiological interviews firmly connect the illnesses to recalled lettuce from the central Mexican operation.

While there is currently not enough evidence to conclusively determine how contamination occurred in this outbreak, the positive samples show that cyclospora was present in the environment where lettuce was grown and processed.

Federal regulators have now closed the investigation and shifted their focus to preventative guidance for growers ahead of the upcoming agricultural season.