FDA Corrects Itself: Mexican Lettuce Did Not Cause ‘Explosive Diarrhea’ Outbreak; It Was a ‘False Positive’

ByLa Jornada Editorial Staff

This article by the La Jornada editorial staff originally appeared in the July 20, 2026 edition of La Jornada, Mexico’s premier left wing daily newspaper.

The United States Food and Drug Administration (FDA) backtracked regarding the origin of the iceberg lettuce that has caused an outbreak of “explosive diarrhea” in that country, and stated that the test pointing to its origin in Mexico was a “false positive.”

In a statement, the FDA said the following:

“Due to the complexity in the detection of Cyclospora, the FDA’s laboratory experts reviewed the sample results again and concluded that the finding does not represent a real amplification and must be considered a false positive.”

It indicated that Taylor Farms was notified and that it continues working with the company to ensure that the product involved in this outbreak has been withdrawn from the market. The FDA and its state partners continue collecting and analyzing product samples.

This past July 17, the FDA had reported that Taylor Farms de México, based in Guanajuato, was related to the “explosive diarrhea” outbreak due to the iceberg lettuces it supplied to the Taco Bell chain. That same day, the company announced the voluntary withdrawal of its product.