The U.S. Food and Drug Administration has walked back a key finding in its investigation into the nation’s ongoing Cyclospora outbreak, acknowledging that a laboratory result linking the illness to Taylor Farms de Mexico was a false positive and leaving investigators once again searching for the source.
The agency said Sunday that laboratory experts re-reviewed testing conducted on a sample of iceberg lettuce and determined the initial finding “does not represent true amplification and should be considered a false positive.” As of July 20, the FDA said there are no confirmed positive product samples for Cyclospora, even as the multistate investigation continues.
The reversal comes just days after the FDA announced its traceback investigation had converged on Taylor Farms de Mexico as the supplier of shredded iceberg lettuce served at Taco Bell restaurants in Indiana, Kentucky, Michigan, Ohio and West Virginia, where illnesses had been reported.
Despite the revised laboratory findings, Taylor Farms said it will maintain its voluntary recall of iceberg lettuce sourced from central Mexico “out of an abundance of caution.” The company said the FDA acknowledged the error and apologized after informing the company that the original laboratory result was incorrect.
The FDA said it continues working with Taylor Farms while federal and state investigators collect and analyze additional product samples. The agency emphasized that the outbreak investigation remains active and that additional suppliers, products or distribution channels could still be identified as more information becomes available.
The investigation has become one of the largest Cyclospora outbreaks in recent years. According to the FDA, 1,644 laboratory-confirmed illnesses tied to the five-state Taco Bell outbreak have been identified, including 94 hospitalizations but no deaths. Separately, the CDC is tracking a broader nationwide increase in Cyclospora illnesses that extends beyond the Taco Bell-related cases.
For grocery retailers and foodservice operators, the latest development underscores both the complexity of modern foodborne illness investigations and the importance of measured communication as scientific findings evolve. While the Taylor Farms recall remains in effect, investigators have not yet confirmed a definitive source of contamination, meaning the industry’s attention remains focused on continued traceback efforts and any additional guidance from the FDA and CDC.