FDA Admits Lettuce Recalled in Parasite Outbreak Was False Positive

The investigation into a multi-state outbreak of the parasite Cyclospora has taken a turn, as the U.S. Food and Drug Administration (FDA) announced that lettuce initially suspected as the source tested negative for the pathogen.

The FDA stated Sunday that a sample of lettuce supplied by Taylor Farms, which had previously tested positive for Cyclospora, was a false positive. The agency's laboratory experts re-evaluated the sample and concluded that the finding did not represent true amplification of the parasite.

"FDA has notified Taylor Farms and continues working with the firm to ensure product implicated in this outbreak has been removed from the market. FDA and state partners continue to collect and analyze product samples," the FDA said in a statement. "As of July 19, 2026, there are no confirmed positive sample results for product testing for cyclospora."

Earlier in the week, Taylor Farms had voluntarily recalled its lettuce grown in Mexico. This action followed reports that the Centers for Disease Control and Prevention (CDC) and the FDA were investigating shredded iceberg lettuce supplied by the company to Taco Bell locations across the U.S. as a potential source of the outbreak.

Taylor Farms stated that none of its products were associated with the outbreak, but it acted based on information from the FDA. Following the FDA's clarification on the false positive, Taylor Farms reiterated that the FDA had not identified a single positive product test result for Cyclospora.

Taco Bell had also taken precautionary measures, voluntarily removing potentially impacted lettuce from a supplier in select states and replacing it. The company stated it was acting out of an abundance of caution and to protect its customers.

The CDC had previously linked illnesses in the outbreak to shredded iceberg lettuce from a single supplier used at Taco Bell restaurants in Indiana, Kentucky, Michigan, Ohio, and West Virginia. Cases of cyclosporiasis have been estimated to have climbed to nearly 7,000 across more than 40 states, though the CDC noted that not all cases are related to this specific outbreak.

Cyclosporiasis is caused by the Cyclospora parasite and is typically transmitted through contaminated food or water, most commonly fresh produce. In the U.S., cases are often linked to imported produce from regions like Mexico, Central America, South America, and the Caribbean. Fresh produce can become contaminated if irrigated or washed with water containing human sewage.

Symptoms of cyclosporiasis include explosive diarrhea, abdominal cramping, nausea, vomiting, and fatigue. Unlike some other foodborne illnesses, symptoms can persist for weeks or recur. Medical professionals recommend seeking testing if diarrhea lasts for more than a few days, as Cyclospora is not routinely tested for. Treatment typically involves the antibiotic trimethoprim-sulfamethoxazole.