FDA: Taylor Farms iceberg lettuce sample produced a false positive for cyclospora

WASHINGTON — A top U.S. Food and Drug Administration official said Monday that a false positive report for the parasite Cyclospora from a Taylor Farms iceberg lettuce sample does not change the basis for an ongoing agency investigation.

The main entrance of Food and Drug Administration Building 1 on the FDA campus in Silver Spring, Maryland. (Photo by Michael J. Ermarth/FDA)

The FDA announced on Sunday a false positive on a Taylor Farms lettuce sample, amid an outbreak of cyclosporiasis that has sickened more than 1,600 people.

But in a call with reporters Monday afternoon, acting FDA Commissioner Kyle Diamantas said the false positive report doesn’t change the basis for the probe or the epidemiological data supporting Taylor Farms’ voluntary recall of some of its iceberg lettuce products.

“I want to stress that our investigation continues, including into other potential sources and commodities for other clusters of illnesses,” he said on the call.

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.”

5 states affected

After an FDA investigation into the source of the outbreak affecting at least five states, which 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 sample that generated the false positive was not part of the current recall, according to FDA acting Deputy Commissioner for Food Donald Prater.

Prater said that it was important to communicate the findings, given the ongoing outbreak and public health risk. The FDA detected the false positive during a subsequent quality check in the lab and immediately issued the correction, he said.

“The reevaluation of the sample does not alter the data supporting the outbreak advisory that prompted the current voluntary recall,” Prater said on the call with reporters Monday. “FDA’s traceback investigation and the outbreak data continue to converge on shredded iceberg lettuce from Taylor Farms’ location in central Mexico.”

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.

Taylor Farms statement

In its own statement Sunday, Taylor Farms said the FDA had “apologized” to the company after informing it of the mistaken result.

“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. “The 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.”

In the call with reporters on Monday, however, an FDA official said that the agency informed the company of the false positive report and explained how it happened, but did not offer an official apology.

“We did not offer an official apology, but did explain the issues factually,” the official said.

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.

The CDC’s webpage on the cyclosporiasis outbreak was last updated on Saturday, before the false positive was announced.

by Sam Gauntt, Virginia Mercury

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