FDA Maintains Lettuce Warning Despite False Positive Test
The Food and Drug Administration said its investigation into a multistate cyclosporiasis outbreak remains focused on shredded iceberg lettuce supplied by Taylor Farms facilities in central Mexico, despite determining that one laboratory result was a false positive. The outbreak has sickened more than 1,600 people across over 30 states, while investigators continue working to identify the precise source and scope of contamination.
The disputed test involved a specific lettuce shipment that regulators do not believe caused the illnesses. FDA officials said the corrected result does not alter traceback evidence connecting the outbreak to recalled Taylor Farms iceberg lettuce. The agency continues advising consumers not to eat recalled products.
Taylor Farms is maintaining its voluntary recall, while Taco Bell said it removed suspected lettuce from affected restaurants and adjusted its supply chain. Walmart also withdrew four Marketside salad kits supplied by Taylor Farms from stores in 27 states as a precaution, although no illnesses had been linked to those products.
The revised test finding has added uncertainty for consumers and food businesses. Michigan health officials continue to recommend whole heads of lettuce instead of bagged or premixed salads. Experts note that cyclospora can be difficult to confirm in laboratories and may take up to two weeks to produce symptoms, complicating efforts to connect illnesses with short-lived produce shipments.
Restaurant traffic data indicate temporary declines at Taco Bell and other chains serving lettuce, including Chopt, Panera Bread and Chipotle. Taco Bell said it completed removals within 72 hours and considers its restaurants safe.
Industry analysts do not expect lasting financial damage, though companies could face weaker sales for one or two quarters. Yum Brands shares fell nearly 9% over five days. Federal and state investigators are continuing to test shipments, review patient interviews and assess whether additional suppliers or ingredients are involved.