Federal health officials have tied a multi-state outbreak of the parasite Cyclospora cayetanensis to shredded iceberg lettuce from Taylor Farms de Mexico, sickening nearly 7,000 people across the United States and triggering a recall spanning 27 states as of July 18, 2026. The FDA formally labeled it a "5-State Outbreak" on its investigation page published July 19, making it one of the largest foodborne parasitic events in recent memory — even as Mexican authorities push back on whether their lettuce is to blame.

The CDC confirmed in its July 18 update that epidemiologic and traceback data point to iceberg lettuce from Taylor Farms de Mexico as the source. A sample of the company's lettuce tested positive for the parasite on July 18, according to the FDA's investigation page. The contaminated product was processed into 5-pound (2.3-kg) bags at Taylor Farms' facility in Guanajuato, Mexico, and shipped to Taco Bell locations, mainly across five states: Indiana, Kentucky, Michigan, Ohio, and West Virginia. The FDA issued its initial outbreak advisory on July 16, telling consumers not to eat recalled iceberg lettuce from Taylor Farms de Mexico and specifically warning about shredded iceberg lettuce from Mexico sold at Taco Bell locations in Indiana.

Taylor Farms de Mexico launched a voluntary recall of all iceberg lettuce sourced from central Mexico on July 17. Sysco separately pulled iceberg lettuce from central Mexico linked to the outbreak. Wendy's and Chipotle both stated they are unaffected. The recall expanded to 27 states the next day, July 18. The FDA planned to inspect Taylor Farms' Guanajuato facility to determine how the parasite got into the lettuce. Taylor Farms operates two processing facilities in Mexico, including one in Baja California.

The human toll has climbed sharply. The CDC reported 1,644 illnesses linked to the Taco Bell lettuce as of its July 17 media release. Michigan alone reported 5,002 cyclosporiasis cases as of roughly July 17, a figure that rose past 6,000 by approximately July 20. Nationwide, there were nearly 7,000 confirmed or suspected cases as of approximately July 20.

Cyclospora cayetanensis is a microscopic parasite that causes cyclosporiasis, an intestinal illness people get when they consume food or water contaminated with fecal matter carrying the parasite's oocyst — a hardy, spore-like stage of the organism. The pathogen is common in certain tropical and subtropical regions and has repeatedly turned up in imported fresh produce in the United States. Unlike bacterial contaminants such as E. coli or Salmonella, Cyclospora cannot be grown in standard lab cultures; confirmation requires specialized microscopy or molecular testing, which can slow the investigation and make it harder to pin down the exact source.

Mexican federal authorities moved quickly to engage. The Secretariat of Health (Secretaría de Salud) and the Secretariat of Agriculture (Secretaría de Agricultura) announced on July 17 that they are collaborating on the U.S. investigation. Three agencies — COFEPRIS (the federal health regulatory commission), the Dirección General de Epidemiología, and SENASICA (the national food safety service) — are coordinating a sanitary, epidemiological, and documentary review of the supply chain tied to the iceberg lettuce in question.

By July 21, however, Mexico's Health Minister stated there is no evidence that lettuce sourced from Mexico caused the outbreak. That assertion was complicated, at least temporarily, by a sample taken in Doctor Mora, Guanajuato state, which initially tested positive for Cyclospora but was later determined to be a false positive. The retraction removes a potential corroborating data point from the Mexican side, even as U.S. traceback and epidemiological evidence continues to converge on the Taylor Farms de Mexico supply chain.

The divergence between U.S. and Mexican characterizations is not unusual in cross-border food safety events involving shared supply chains, but it carries practical consequences. Mexican agricultural exports to the United States depend on regulatory confidence, and a contested outbreak can ripple through sourcing decisions across the entire quick-service restaurant sector. The FDA's planned inspection of the Guanajuato facility may prove pivotal in resolving the evidentiary gap, though inspection timelines and the technical difficulty of identifying environmental contamination sources for Cyclospora mean definitive answers could take weeks.

The scale of this outbreak also raises structural questions about pre-shredded, bagged lettuce distributed through centralized processing facilities. The product format — 5-pound bags processed at a single Mexican facility and distributed to a national fast-food chain — means contamination at one point in the chain can reach consumers across multiple states simultaneously. The number of affected states, the case count, and the involvement of a major supplier and a national restaurant chain place this event in a different category from typical seasonal cyclosporiasis clusters, which tend to be smaller and harder to trace.

For now, the recall remains active, the CDC and FDA investigations continue, and Mexican regulators are conducting a parallel review whose findings may or may not align with the U.S. conclusion. The Taco Bell lettuce advisory for the five-state region remains the FDA's operative consumer guidance.