Federal regulators have begun an inspection of Taylor Farms’ central Mexico processing plant, which has been linked to a massive multistate outbreak of cyclosporiasis, a parasitic infection that causes severe gastrointestinal illness.

The Food and Drug Administration is conducting the inspection and collecting samples at Taylor Farms de Mexico in Guanajuato, the agency said on Aug. 13. The move comes nearly a month after the Salinas, California-headquartered company announced on July 17 that it was voluntarily removing all iceberg lettuce sourced from central Mexico from the U.S. market.

Outbreak by the numbers

The cyclospora outbreak — caused by the parasite Cyclospora cayetanensis — has reached unprecedented scale. The CDC has reported 13,895 laboratory-confirmed cases across 47 states between May 1 and its latest update on Aug. 10, though the agency’s numbers lag significantly behind state reporting. Michigan alone has confirmed 12,485 cases since May 1, including the first two deaths identified in the nationwide outbreak. State health officials there have outpaced federal agencies in tracking and reporting infections.

Symptoms of cyclosporiasis include watery diarrhea, cramping, gas, nausea and fatigue. In many cases, patients experience “explosive” diarrhea.

The false positive that confused the investigation

The FDA’s investigation hit a snag in July when a lab test initially found cyclospora contamination in a sample of Taylor Farms shredded iceberg lettuce. But on July 19, the agency walked back that finding, announcing the result was a false positive. “As of July 19, 2026, there are no confirmed positive sample results for product testing for Cyclospora,” the FDA said in a statement.

Taylor Farms issued a press release saying the FDA had apologized. “To be clear, at this moment, FDA has not identified a single positive product test result for Cyclospora,” the company said.

However, the FDA quickly clarified that the false positive did not clear Taylor Farms from suspicion. “To clarify, this false-positive lab sample DOES NOT change the basis for FDA’s ongoing outbreak investigation or the overwhelming epidemiological data supporting the current voluntary recall by Taylor Farms,” the agency posted on X on July 20.

The investigation continues

Donald Prater, the FDA’s acting deputy commissioner for food, told The Washington Post that agricultural water is often the cause of cyclospora contamination. The FDA is “looking carefully at the available data to be able to understand what could have happened,” he said.

Taylor Farms, which suspended processing and distribution of iceberg lettuce and brought in outside inspectors at its central Mexico plant, has also been cooperating with the investigation. The company had initially taken action on July 17, a day after the CDC, FDA and state health officials linked a single supplier of lettuce served at Taco Bell restaurants to the ongoing outbreak.

Recalled products and safety guidance

Taylor Farms’ voluntary recall included iceberg lettuce products distributed to retailers including Walmart and Taco Bell. Walmart recalled some bags of Marketside Bagged Iceberg Salad and Shredded Iceberg Salads sold in 27 states.

As of mid-August, most of the affected produce is “likely” no longer available to consumers, according to Michigan health officials. The state’s health department said on Aug. 6 that residents “can resume routine guidance for consuming lettuce and salad greens” and that the broad precautionary recommendation to avoid bagged salad mixes is no longer in effect.

New cases and associated hospital visits are now on the downswing, the department added. However, with public trust damaged to the point that eateries associated with the outbreak have seen a notable dip in foot traffic, it may take more than one assurance to send shoppers back to bagged lettuce.