The Food and Drug Administration said Friday it has closed its investigation into the cyclospora outbreak tied to shredded iceberg lettuce from Taylor Farms de Mexico, announcing that inspectors finally found the parasite at the Mexican operation at the heart of the crisis.
During onsite inspections at the company's central Mexico processing facility in Guanajuato state and at several iceberg lettuce growers, FDA teams collected samples of water, soil, sediment and lettuce. Two samples tested positive for Cyclospora: one from a tank holding outgoing wastewater at the Taylor Farms de Mexico processing plant, and one from a drainage ditch at an iceberg lettuce grower identified in the agency's traceback investigation.
The FDA said the findings show the parasite "was present in the environment where lettuce was grown and processed," adding to "strong epidemiological data and traceback convergence" linking the outbreak to the recalled lettuce. But the agency was candid about the limits: there is "not enough evidence to conclusively determine how contamination occurred."
The final federal tally: 12,883 confirmed illnesses, 570 hospitalizations and two deaths across 21 states — the largest recorded multistate cyclospora outbreak in U.S. history. The last illness onset was August 17. The CDC declared the outbreak over on September 11, saying it was confident all recalled lettuce was off the market.
The first alarm came in July, when diners at Taco Bell restaurants began falling ill with severe diarrhea. Data from Michigan health officials showed that 90 percent of patients who had eaten at Taco Bell reported eating iceberg lettuce. On July 17, Taylor Farms voluntarily recalled all iceberg lettuce sourced from central Mexico — including Marketside-brand shredded iceberg sold at Walmart and bulk lettuce supplied to Taco Bell, Jack in the Box and Sysco, the country's largest food distributor. At the outbreak's peak, more than 1,000 infections were recorded in a single day.
The FDA's visit to the Guanajuato facility in August was its first in more than seven years. Foreign food safety inspections collapsed after the COVID-19 pandemic, and the agency has lagged on the inspection targets Congress set. CBS News reported the farm linked to the outbreak had not been inspected in seven years.
Taylor Fresh Foods, the parent company, pushed back on the findings. It attributed the contamination to an independent grower "who is no longer part of our supplier program," noting the FDA-referenced sample came from "discharged waste and sewer water outside of our processing facility." The company said its central Mexico facility remains closed while it works with researchers to implement enhanced safety protocols "from the field to the facility."
Cyclosporiasis is caused by the microscopic parasite Cyclospora cayetanensis, which reaches food through water or soil contaminated with human feces. The CDC describes the hallmark symptom as watery diarrhea "with frequent and sometimes explosive bowel movements." The illness rarely passes directly from person to person — which is why investigators keep coming back to the water.
The Taylor Farms outbreak was only part of a grim 2026 for cyclospora. The CDC counted 19,595 domestically acquired cases between May and August, compared with 1,180 in the same period of 2025. The FDA says it is investigating four additional outbreaks with unidentified food vehicles. Lawsuits against Taco Bell and Taylor Farms were already filed in July.
The FDA says it will continue genotyping clinical specimens to try to match the environmental samples to patients — but the investigation itself is over, with the central question unanswered: how did human waste get onto enough lettuce to sicken nearly 13,000 people?