The FDA lab check that exists to catch a cyclospora false positive.
FDA suspended proficiency testing for the national food lab network in April 2025 after losing four positions. A retracted lab result doesn’t clear Taylor Farms or Taco Bell.
Last week, the FDA reported that a sample of Taylor Farms shredded iceberg lettuce had tested positive for cyclospora. Then on Sunday, July 19th, it took that back, saying that it had been a false positive test result.
Why a lab test rarely solves a produce outbreak.
Investigators name a source three ways: they interview sick people about what they ate, trace the supply chain back from where they ate, and test the food itself.
Testing the food isn’t usually what solves the case. By the time a produce outbreak is spotted, the lettuce has been eaten or thrown out, and contamination sits in patches, so a clean sample can come from a dirty lot. Most produce outbreaks are solved based on interviews, what we call “shoe leather epidemiology,” public health workers literally wearing out their shoes, going into communities, hospitals, restaurants, farms, food distributors, homes, and more to gather evidence firsthand.
The CDC says the link comes from “epidemiologic and traceback data.” Sick people reported eating at the same restaurants. FDA followed the chain back to one supplier of shredded iceberg from Mexico. Neither finding depended on a positive sample.
Everyone is still pulling the lettuce.
The FDA didn’t withdraw the warning. The same July 19th notice that pulled the sample still tells people not to eat recalled iceberg lettuce from Taylor Farms de Mexico. It says the investigation is ongoing and calls the company’s lettuce “product implicated in this outbreak.” A MedWatch recall notice went out this morning.
Taylor Farms de Mexico, of Guanajuato, is pulling all iceberg lettuce grown in central Mexico from the U.S. market. Taco Bell says it took the lettuce out of every restaurant as of July 17th. Walmart pulled four bagged iceberg products from stores in 26 states, though it says there’s been no sign that its own products were affected. Mexico’s health and agriculture ministries opened a review of the supply chain.
Two lawsuits were filed before the retraction, both on July 17th. Ron Simon & Associates and DiCello Levitt sued Taco Bell and Taylor Farms in Ohio state court for David Ott, a 27-year Army veteran. Marler Clark and Darr Law filed Caruso v. Taco Bell in federal court in northern Ohio, the first case to name Taylor Farms as a defendant. Both claims are based on the government’s traceback.
FoodNet, the FDA’s lab checks, and the budget.
Two systems were cut before this outbreak started.
FoodNet is the country’s only active tracking system for foodborne illness. CDC, USDA, FDA, and ten state health departments run it, covering about 16% of the population. Active means staff stay in touch with more than 700 clinical labs and audit them, instead of waiting for reports to come in. FoodNet isn’t how outbreaks are spotted. It’s how you know what a normal year looks like, so you can tell a real surge from better reporting. On July 1, 2025, it went from tracking eight pathogens to two. Cyclospora had been on that list for 28 years.
The second is the proficiency testing program for the national food testing lab network. It sends labs blind samples to confirm they can find a given hazard, cyclospora among them. In April 2025, after job cuts that took a quality assurance officer, a chemist and two microbiologists, the FDA suspended it, at least through that September. I asked HHS whether it’s running again. The agency wouldn’t say. Proficiency testing exists to catch a wrong lab result before it goes public.
Meanwhile Congress is setting the CDC food safety budget now. FoodNet’s funding is paid out of a single CDC food safety account, funded at $74 million this year. FoodNet’s share has sat at $5 to $6 million a year for a decade while its workload grew, and the CDC dropped from eight pathogens to two last year, saying it needed to conserve resources. Food safety experts, joined by the Meat Institute and the grocery industry, have asked for $111 million, a 50% increase, to turn the other six pathogens back on. The White House asked for $107 million. The House bill offers $79 million, and directs the increase to lab and informatics modernization.
The other two agencies are in a separate bill, and they fare better. FDA’s Human Foods Program, responsible for lettuce, would get $1.279 billion, a $108 million increase and within a rounding error of what the White House asked for. That account had been flat since 2023. USDA’s Food Safety and Inspection Service would get $1.226 billion, up $10.8 million, all of it for state inspection programs. FSIS inspects meat, poultry and eggs. It has no authority over lettuce.