WASHINGTON — The U.S. Food and Drug Administration announced Sunday that the Taylor Farms lettuce sample that tested positive for the parasite cyclospora was actually a false positive. 

The announcement comes after the FDA previously reported on Saturday that a sample of iceberg lettuce from Taylor Farms in central Mexico had tested positive for the parasite. As of Sunday, the FDA said there are no confirmed samples of Taylor Farms lettuce testing positive for cyclospora.

The FDA did not cite any other positive tests for the source of the outbreak, which has been linked to severe gastrointestinal illness.

As of Monday morning, a banner on an FDA webpage tracking the outbreak still reads: “Do not eat recalled iceberg lettuce from Taylor Farms de Mexico. FDA’s investigation is ongoing.”

The FDA also said: “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.”

After an FDA investigation into the source of the outbreak affecting at least five states identified shredded lettuce provided by Taylor Farms and sold in many Taco Bell restaurants in the United States as a potential reason, the California-based produce firm announced a voluntary recall of many of its lettuce products. 

The FDA and Taylor Farms continue to work together to ensure that “product implicated in this outbreak” has been removed from store shelves and not sold on the market, the Sunday statement continued. 

In its own statement Sunday, Taylor Farms said the FDA had apologized to the company. 

“Based on initial information provided by health officials, in an abundance of caution, we completed a voluntary recall of iceberg lettuce from central Mexico,” the company’s statement read. “Recalled product was limited to iceberg lettuce grown and processed in central Mexico. All other Taylor Farms products, including all Taylor Farms brand products available for purchase, are not involved in the recall.” 

The multistate outbreak of the parasite has mostly been concentrated in the Great Lakes and Appalachian regions, with cases identified in Michigan, Ohio, Indiana, Kentucky and West Virginia, according to the FDA. 

The Centers for Disease Control and Prevention says there have been more than 1,644 confirmed cases of cyclosporiasis, the food-borne illness caused by ingestion of the parasite, with 94 of those cases leading to hospitalization. There have been no reported deaths.