FDA’s false positive doesn’t clear Taylor Farms

The FDA said “lettuce get this right.” The agency retracted its claim that it had found the sickness-causing cyclospora parasite in a sample of Taylor Farms lettuce over the weekend, saying yesterday that the test was a false positive. But don’t go preparing that salad kit in your fridge just yet—the FDA still believes the company’s iceberg lettuce is linked to the multi-state outbreak.Here’s what we know about the illness’s probable connection between the company whose clients include Walmart, Whole Foods, Costco, Taco Bell, and McDonald’s and the gastrointestinal ailment that’s got Americans straddling toilets in agony:Last week, the outbreak of explosive diarrhea (as if there’s any other kind) was linked to shredded lettuce from a single supplier to Taco Bell restaurants in five states.On Friday, Taylor Farms issued a voluntary recall of its iceberg lettuce grown in central Mexico that was sold between June 29 and July 16 across 27 states. The recall remains in place.Despite the false positive, the FDA clarified yesterday that, unlike the Titanic captain, it still considers the iceberg a serious problem. “FDA’s traceback investigation and outbreak data continue to converge on shredded iceberg lettuce from Taylor Farms locations in central Mexico,” the agency said in a statement.In its own statement, Taylor Farms said that the FDA “apologized to us” for the false positive, noting that besides the lettuce from Mexico, “all other Taylor Farms products…are not involved in the recall.”How did the false positive happen?An expert told the Wall Street Journal that cyclospora is impossible to grow in a lab, making it harder to study and link to a common source because scientists can’t culture more of it to test.Another scientist interviewed by MarketWatch said the complex nature of the pathogen could have resulted in the test detecting a similar organism.More cases are likely coming: As of July 15, the FDA said there have been more than 1,600 confirmed cyclospora cases in the US and another 5,100+ it is working to confirm.—DL