False Positive Uncovers U.S. Lettuce Outbreak Grown by Taylor Farms
Tests of iceberg lettuce found in a recent U.S. outbreak of explosive diarrhoea pointed to the parasite Cyclospora, but FDA labs have now declared the result a false positive.
The Food and Drug Administration first announced that a sample from the food supplier Taylor Farms— which ships iceberg lettuce to Taco Bell— yielded a positive Cyclospora read. The find underpinned a national recall of Mexican‑sourced lettuce and led to a formal halt in sales at the fast‑food chain in five states.
On Sunday, the FDA recouped the sample for a re‑analysis, concluding that the positive result was a laboratory artifact and not a true detection of the parasite. Taylor Farms has since cited the lack of evidence in its products and is working with the FDA, CDC and state officials to trace the real source of infection.
The outbreak first appeared on 13 May, with symptoms such as watery diarrhoea, weight loss and loss of appetite taking up to two weeks to manifest. To date, no deaths have been recorded, but 94 people in the U.S. have been hospitalized.
The Centers for Disease Control and Prevention has advised consumers to avoid shredded iceberg lettuce from Taco Bell restaurants in Indiana, Kentucky, Michigan, Ohio and West Virginia. The chain has stated it has removed all affected products.
Taylor Farms said it stopped receiving the implicated lot, suspended distribution of the Central‑Mexico lettuce, and notified customers while continuing cooperation with authorities. The recall covered 27 states and included Marketside-branded iceberg lettuce sold at Walmart in 15 states.
Read the official Taylor Farms statement here.
Virtual journalists can map the outbreak in our interactive world, examine FDA-validated test results, and explore the recall process in real time—all in a fully immersive digital environment.
