Thousands Sick, One Test Pulled: FDA Walks Back Cyclospora Finding on Taylor Farms Lettuce

More than 2,400 people have fallen ill with cyclosporiasis since May, and on July 19 the Food and Drug Administration quietly walked back the single lab result that had put a name on the outbreak's likely source. The agency's positive Cyclospora test on a sample of Taylor Farms de Mexico iceberg lettuce was, in the agency's own words, a false positive — discovered only after FDA lab experts re-reviewed the work and concluded the finding could not stand. The reversal has not changed the recall on grocery shelves, and it has not changed the agency's working theory about where thousands of Americans got sick. It has changed the evidentiary floor under both. ²⁷⁸

What the FDA has not done is issue a formal apology. Taylor Farms said the agency apologized over the false-positive result, but an FDA official told reporters the agency notified the company of the re-review and explained the conclusion — it did not, in that official's account, apologize. The two versions are on the record and they have not been reconciled. ¹¹

By Monday, July 20, the agency had restated its position in clearer terms: the data continue to converge on shredded iceberg lettuce from Taylor Farms de Mexico, even with the positive sample now off the board. ⁴⁵⁶ A top FDA official added that the false positive "does not change the basis for" the investigation. ⁹ In other words, the lab slip has been logged and the case has not been reopened from scratch.

The outbreak was first detected in May and has grown into one of the larger cyclosporiasis events the agency has worked in recent years. Federal health officials have been investigating five clusters of cases; the largest is tied to Taco Bell restaurants in five states — Indiana, Kentucky, Michigan, Ohio and West Virginia — where the common thread on the menu is iceberg lettuce. ⁸¹⁰ That epidemiological thread is what pointed investigators at Taylor Farms in the first place, and it is what kept the agency's focus there after the lab finding collapsed.

The recall itself was voluntary. Taylor Farms pulled iceberg lettuce — and salad kits containing it — sourced from its Mexico operations, and that recall remains in effect. ²⁵⁸ The agency's reason for keeping it in place is the same reason the case count keeps climbing: there is no other candidate food on the table. Until one is found, the recall is the only consumer-facing lever the agency can pull.

The most public friction is about the word "apology." Newsweek reported that Taylor Farms said the FDA apologized over the false positive; the FDA's own characterization, per the same Newsweek account, is that it explained the re-review to the company without offering an apology. ¹¹ Readers should treat the existence of a formal apology as disputed, not confirmed. The substance of the re-review — that the test was wrong — is not in dispute.

A second, quieter disagreement runs through the public framing. The FDA's language is that the false positive does not undercut the investigation. Outside food-safety experts note that PCR testing for Cyclospora is fast and sensitive but can produce false positives when not properly confirmed, which is exactly what an agency re-review is designed to catch. The result is an investigation still pointing at Taylor Farms lettuce but now pointing at it on epidemiological grounds alone, with no positive sample to anchor the chain of custody.

For consumers, the practical line has not moved. The recall covers iceberg lettuce and salad kits with iceberg from Taylor Farms de Mexico, distributed across 27 states, and the agency has not told the public to do anything different. ² What has changed is the evidence behind that instruction: one of the agency's two main reasons to suspect Taylor Farms — the positive sample — has been pulled. The other reason, the epidemiology, still points the same way. The agency is, in effect, asking the public to keep acting on half a case while it rebuilds the other half.