FDA Says Lettuce Test Was a False Positive, Leaving Cyclospora Outbreak Source in the Dark

On a quiet Thursday morning, the U.S. Food and Drug Administration sent out an apology that felt more like a sigh of relief than a triumph. In an emailed statement the agency admitted that the laboratory test which had pointed a finger at iceberg lettuce from Taylor Farms was, in fact, a false positive. In plain words: the lettuce isn’t proven to be the source of the Cyclospora outbreak that has plagued 34 states.

The revelation came just days after Taylor Farms, the California‑based supplier that sources a large portion of its lettuce from central Mexico, announced a voluntary recall of all its iceberg lettuce from that region. The recall, issued on Friday, July 18, 2026, was a precautionary move – the lot that originally tested positive was not part of the recall, and its status on grocery shelves remains murky.

Meanwhile, the numbers keep climbing. Michigan, the epicenter of the outbreak, has logged 5,002 confirmed cases of cyclosporiasis, a diarrheal illness caused by the parasite Cyclospora cayetanensis. More than a hundred of those patients have been hospitalized, and the Centers for Disease Control and Prevention (CDC) says cases have now been reported in 34 states.

What exactly is cyclosporiasis? Think of a bout of stomach flu that just won’t quit – explosive, watery diarrhea that can last a week or longer, with fatigue and abdominal cramping that make daily life miserable. For most healthy adults it isn’t deadly, but it can be severe enough to land people in the hospital, especially the very young, the elderly, or anyone with a weakened immune system.

Taylor Farms, whose sprawling greenhouses sit near Salinas, California, quickly responded to the FDA’s initial findings. The company’s spokesperson told reporters that the lettuce in question was grown in central Mexico, a region that supplies a significant share of the U.S. market. “We are fully cooperating with the FDA and public health officials,” the spokesperson said, adding that the company had already pulled the affected batches from distribution.

But the FDA’s reversal throws a wrench into the investigation. Without a confirmed link, public‑health officials are left chasing a phantom, and consumers are left wondering whether the crisp, head‑shaped lettuce they pick up at the deli counter is safe.

“Our priority is always the health and safety of the public,” the FDA’s email reiterated. “We are reviewing our testing protocols to ensure this does not happen again.” The agency did not specify whether the false‑positive result stemmed from a lab contamination issue, a technical glitch, or a simple human error – details that may never be fully disclosed.

For now, the best advice remains the same: wash all fresh produce thoroughly, keep an eye on any new recalls, and stay informed through reliable sources like the CDC and FDA. As the investigation continues, the food‑industry watchdogs and the millions of Americans hoping for an end to the outbreak can only wait for clearer answers.