The U.S. Food and Drug Administration (FDA) has retracted an earlier claim that a sample of Taylor Farms lettuce tested positive for the Cyclospora parasite, calling the result a “false positive” after retesting. The reversal comes as the agency continues to investigate a multistate outbreak of cyclosporiasis, which has sickened over 1,600 people and prompted widespread recalls of lettuce products.
FDA Reverses Cyclospora Finding
The FDA announced Sunday that laboratory experts had re-reviewed a sample of shredded iceberg lettuce from Taylor Farms de Mexico and concluded the initial positive test for Cyclospora was incorrect. Due to the complexity in detection of Cyclospora, FDA laboratory experts re-reviewed the sample results and have concluded that the finding does not represent true amplification and should be considered a false positive,
the agency stated. As of Sunday, the FDA reported no confirmed positive samples for Cyclospora in its testing.
The agency had previously linked the outbreak to Taylor Farms’ lettuce, which was supplied to Taco Bell restaurants in Indiana, Kentucky, Michigan, Ohio, and West Virginia. Taylor Farms said the FDA “apologizedfor the error, adding,
Today, we were informed that FDA made a mistake, and this was a false positive.”
Taylor Farms Recalls, Apologizes
Taylor Farms had voluntarily removed iceberg lettuce sourced from central Mexico out of an abundance of caution
after the initial positive test. The company stated it would continue cooperating with health officials. Our thoughts remain with everyone who has fallen ill in this outbreak,
Taylor Farms said in a statement. The recall initially targeted lettuce from the region but was later expanded to include four Marketside-brand salad products sold at Walmart.
Walmart removed the affected products from its stores in over two dozen states, citing no indication that products sold in our stores are affected
but acting as a precaution. The company emphasized that no illnesses had been confirmed linked to the products. Taco Bell also said it had completed removal of affected Taylor Farms lettuce from our restaurants,
following the FDA’s initial findings.
Outbreak Impacts 34 States
The cyclosporiasis outbreak, first reported in May, has spread to 34 states, with the CDC confirming 1,645 cases and 141 hospitalizations as of July 13. However, state health departments have reported significantly higher numbers. Michigan, for example, recorded over 5,000 confirmed cases as of July 16, far exceeding its usual annual total of about 50. The CDC has not reported any deaths linked to the outbreak.
Cyclosporiasis, caused by a parasite transmitted through contaminated food or water, causes symptoms including watery diarrhea, cramping, and fever. The illness typically lasts weeks and is treatable with antibiotics. Outbreaks often occur in late spring and summer, with past incidents linked to bagged salads, cilantro, and other fresh produce. The CDC warned that cases may continue through August, the peak of the season.
Lab Testing Challenges Highlighted
The FDA’s retraction underscores ongoing challenges in detecting Cyclospora, a parasite that is difficult to identify due to its resistance to standard disinfectants. A separate source revealed that the FDA suspended a program in 2025 to validate lab capabilities for detecting contaminants, including Cyclospora, due to staffing shortages. The program, which tested about 170 labs, was paused for nearly five months, coinciding with the peak of the 2025 cyclosporiasis season.
Public health experts have criticized the lack of mandatory testing for Cyclospora in produce, despite validated methods available. The FDA’s current approach relies on voluntary testing, and there are no federal rules requiring growers or processors to screen for the parasite. Washing your produce reduces the risk but doesn’t remove it,
one expert noted, emphasizing that heat is the only reliable way to kill the parasite.
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