FDA Keeps Taylor Farms Lettuce at Center of Cyclospora Probe Despite False-Positive Result

The U.S. Food and Drug Administration said on July 20 that its investigation into a cyclosporiasis outbreak remains focused on shredded lettuce supplied by Taylor Farms despite a false positive test result.

Health regulators said on July 18 that a sample of Taylor Farms’ shredded lettuce from central Mexico tested positive for cyclospora, the parasite that causes the gastrointestinal disease, before reversing course on July 19, saying the result was a false positive.

Despite the finding, the FDA said on July 20 that the basis for its investigation linking Taylor Farms’ lettuce to cyclosporiasis outbreak remains unchanged.

“FDA’s traceback investigation and outbreak data continue to converge on shredded iceberg lettuce from Taylor Farms locations in central Mexico,” the agency said in a post on X.

The FDA said it would continue working with federal and state partners to investigate the outbreak and urged the public to avoid consuming “all products listed in Taylor Farms’ voluntary recall.”

The agency said on July 19 that it continued to collect and analyze product samples, but noted there had been “no confirmed positive sample results” for cyclospora.

Taylor Farms said in a July 20 statement that it has stopped sourcing iceberg lettuce from central Mexico for the remainder of the growing season and instructed experts on site to investigate possible sources of contamination there.

“We are committed to working closely with health officials during this ongoing investigation,” Taylor Farms said. “We remain deeply concerned for the health of those who are ill and will provide any updates relevant for your health.”

Taylor Farms initiated a voluntary recall of iceberg lettuce—which was served at Taco Bell restaurants—on July 17 after the Centers for Disease Control and Prevention and the FDA launched an investigation into the lettuce’s possible link to the parasite.

The lettuce was served at Taco Bell locations in five states.

More than 1,644 people infected with cyclosporiasis had reported eating at Taco Bell restaurants in Indiana, Kentucky, Michigan, Ohio, and West Virginia—before falling ill, the CDC said on July 17. Taco Bell said on July 16 that it had removed all impacted lettuce from its stores.

Symptoms of cyclosporiasis include loose, watery stool and abdominal pain. Diagnosis typically involves testing stool samples. Antibiotics are usually the preferred treatment.

Health agencies are advising people to wash their hands before and after handling produce, wash produce before preparing, and consider cooking produce before consumption.

Michigan Department of Health and Human Services said it has detected 6,148 cyclosporiasis cases in the state as of July 20, including 102 patients who have been hospitalized. No deaths have been reported.

Zachary Stieber contributed to this report.