The FDA has withdrawn its report that a Taylor Farms lettuce sample tested positive for Cyclospora, saying the result was a false positive.
Taylor Farms says the reversal supports its position that no product testing has confirmed Cyclospora in its lettuce, but federal investigators say epidemiological and supply-chain evidence still point to the company.
The recall remains in effect, and consumers should not eat the affected iceberg lettuce even though the laboratory result was invalid.
Taylor Farms is pushing back against the suggestion that its lettuce has been conclusively identified as the source of a large Cyclospora outbreak after the Food and Drug Administration (FDA) acknowledged that a supposedly positive product test was wrong.
On July 18, the FDA reported that a sample of lettuce supplied by Taylor Farms de Mexico had tested positive for Cyclospora, a microscopic parasite that can cause prolonged diarrhea and other gastrointestinal symptoms.
One day later, the agency reversed itself. FDA laboratory experts reexamined the results and concluded that the finding did not represent “true amplification,” meaning the test should be considered a false positive.
“As of July 19, 2026, there are no confirmed positive sample results for product testing for Cyclospora,” the FDA said in its updated investigation notice.
Taylor Farms quickly highlighted the mistake.
“FDA informed Taylor Fresh Foods that one of its iceberg lettuce products from central Mexico tested positive for Cyclospora,” the company said. “Today, we were informed that FDA made a mistake, and this was a false positive.”
Taylor Farms said the FDA apologized to the company, although the agency reportedly disputed that characterization. Regardless, the FDA has publicly acknowledged that the laboratory result was invalid and removed references to it from its earlier update.
Taylor Farms remains under investigation
The false positive does not fully clear Taylor Farms, however.
Federal health officials say their investigation was not based solely on the product test. The FDA said Monday that epidemiological evidence and product-tracing records continue to converge on shredded iceberg lettuce from Taylor Farms operations in central Mexico.
The agency said the erroneous test “does not change the basis” for the continuing investigation or the evidence supporting the company’s voluntary recall.
The Centers for Disease Control and Prevention (CDC) has also said epidemiological and traceback evidence links Taylor Farms de Mexico iceberg lettuce to illnesses reported in Indiana, Kentucky, Michigan, Ohio, and West Virginia.
Among 190 patients who reported eating at Taco Bell and provided detailed food information, 90% said they ate iceberg lettuce, according to the CDC. Investigators traced the lettuce supplied to affected restaurant locations to Taylor Farms de Mexico.
As of the latest federal update, the five-state outbreak included 1,644 confirmed illnesses, 94 hospitalizations, and no deaths.
Taylor Farms said its recall was initiated “in an abundance of caution” based on information supplied by health officials. The company removed all iceberg lettuce sourced from central Mexico from the U.S. market, even though investigators had focused on a specific independent farm that accounted for less than 1% of the nation’s iceberg lettuce supply.
The company stressed that other Taylor Farms products, including Taylor Farms-branded products available to consumers, are not included in the recall.
Recall remains in effect
The FDA is continuing to advise consumers, restaurants, and retailers not to use recalled iceberg lettuce distributed by Taylor Fresh Foods. The recall includes certain Marketside iceberg salad and shredded lettuce products sold at Walmart, along with numerous products distributed to restaurants and other food-service customers.
Taco Bell said it stopped using lettuce from Taylor Farms de Mexico on July 17.
Consumers who have recalled lettuce should throw it away or return it for a refund. Surfaces and containers that touched the lettuce should also be cleaned and sanitized.
The false positive leaves the investigation in an unusual position: Taylor Farms remains the government’s leading focus based on illness patterns and supply-chain records, but there is currently no laboratory-confirmed product sample proving that its lettuce contained the parasite.