According to an internal U.S. Food and Drug Administration (FDA) report uncovered by NBC News, an Escherichia coli O157:H7 outbreak sickened 89 people across 15 states in November 2024, resulting in 36 hospitalizations, seven cases of hemolytic uremic syndrome (HUS), and one death. FDA made its first public mention of the outbreak in its Coordinated Outbreak and Response Evaluation (CORE) Investigations Table after the investigation was closed, but did not disclose details about the outbreak nor the implicated firms.

Per the internal FDA report, the agency made no public communications about the outbreak and firms were not named because there was no relevant product remaining in commerce by the time FDA opened its investigation.

Many patients fell ill after eating salads at catered events, schools, and restaurants. Cases were reported in Arkansas, Colorado, Illinois, Indiana, Kansas, Missouri, Montana, North Dakota, Nebraska, Ohio, Pennsylvania, South Dakota, Tennessee, and Wisconsin. Whole genome sequencing (WGS) showed that the cases were genetically related.

Epidemiological and traceback investigations pointed to romaine lettuce, provided by a sole processor that sourced the lettuce from a single grower, as the vehicle of illness. Additionally, romaine lettuce that made people sick was traced back to a common ranch and lot. FDA conducted an on-farm investigation at the grower of interest, but the agency made no notable observations.

Although no grower or firm was officially implicated or named by FDA, Bill Marler, a prominent personal injury attorney most known for representing foodborne illness victims and one of the original sources that reported on the undisclosed E. coli outbreak, has filed several lawsuits against Taylor Farms, based in California’s Salinas Valley, in relation to the outbreak. On why he filed lawsuits against Taylor Farms, Mr. Marler said, by looking at WGS data, "[The Marler Clark law firm's] on-staff epidemiologist determined that the common link was that all clients consumed Taylor Farms romaine lettuce in the outbreak period." Taylor Farms, however, refutes this assertion, saying, "Taylor Farms product WAS NOT the source of the referenced 2024 E. coli outbreak. We perform extensive raw and finished product testing on all our product and there was no evidence of contamination.” The company also said that it is "considering all legal action to defend itself," highlighting its pathogen testing program, use of verified wash systems, and continuous improvements to its food safety program supported by third-party certifications.

FDA declined to comment on whether Taylor Farms produced the implicated lettuce, saying it was restricted by federal law from disclosing confidential commercial information. Regarding any potentially involved firm, the internal FDA report said, “No product or firm actions were taken by FDA during this investigation… [redacted firm] performed an internal investigation to review production and testing data as well as distribution patterns. The firm confirmed that both the raw material testing and finished product testing of the lot did not indicate the presence of E. coli. [Redacted firm] reported taking additional investigative steps, including an onsite review of the [redacted] ranch.”

Frank Yiannas, former FDA Deputy Commissioner for Food Policy and Response, explained in a statement provided by Taylor Farms, "If FDA lacked sufficient scientific evidence to publicly identify a farm or firm, it would make sense for them not to name a company," as it would "do more harm than good." In a statement to NBC News, Mr. Yiannas also called FDA's lack of transparency about the outbreak "disturbing."