FDA says Taylor Farms lettuce test was false positive for Cyclospora

The Food and Drug Administration said a test that had flagged a sample of lettuce from Taylor Farms de Mexico as positive for the parasite Cyclospora was later determined to be a false positive. The agency removed the result from its public updates and noted that, as of July 19, 2026, no confirmed positive samples have been identified.

Taylor Farms continues its voluntary recall of iceberg lettuce sourced from central Mexico, which was initially issued after the FDA linked the product to a multi-state outbreak that sickened thousands of people. The recall covers lettuce distributed to stores in 27 states and to Taco Bell locations in five states.

In a statement, Taylor Farms said the FDA had made a mistake and reiterated that no single product test has confirmed Cyclospora contamination. The company said it will keep cooperating with public-health investigators.

The FDA explained that the erroneous result stemmed from false amplification during laboratory testing, a process that can sometimes generate inaccurate findings. Experts noted that detecting Cyclospora is technically challenging and that false positives can occur.

Donald W. Schaffner, chair of the Department of Food Science at Rutgers University, said the recall was appropriate regardless of the test outcome and praised the FDA for acknowledging the error. He warned that the situation could cause confusion among consumers and called for agencies to provide more data on test reliability when announcing results.