By Ahmed Aboulenein, Yasmeen Abutaleb and Julie Steenhuysen
WASHINGTON, July 20 (Reuters) – The U.S. FDA on Monday said the basis for linking Taylor Farms’ lettuce from Central Mexico to the largest U.S. foodborne illness outbreak in recent years remains unchanged, defending its decision to publicize a sample that a later review found was a false positive for the cyclospora parasite.
On Saturday, the Food and Drug Administration said a border-surveillance lettuce sample of Taylor Farms de Mexico product tested positive for cyclospora, but on Sunday, it called that a false positive after a re-review.
The agency said on Monday that it publicized the positive result before completing a quality-control review because the sample fell outside the scope of Taylor Farms’ recall, and it was facing an outbreak that was making people sick.
Acting FDA Commissioner Kyle Diamantas said the outbreak cluster involves more than 1,600 cases across multiple states, with some illnesses reported as recently as last week, making it imperative to keep contaminated product off the market.
Michigan health officials separately reported 6,148 cases linked to the outbreak on Monday, an increase of 1,146 cases since their last update on Friday. The outbreak has resulted in 102 hospitalizations in the state, with no deaths reported.
The outbreak has been linked to Yum Brands’ Taco Bell restaurants in Michigan and four other states.
Diamantas said the agency has investigated five subclusters of cyclospora illness nationwide since the season began in May, three of which are already considered over.
“We found it was important to share this actionable public health information,” Acting Deputy Commissioner for Food Donald Prater said on a call with reporters. “Subsequently, during a quality check by our laboratory personnel, we did detect the false positive, and we did issue a correction.”
The border test result is separate from the U.S. outbreak investigation, which relies on epidemiological and traceback evidence that stands on its own, said a public health laboratory scientist who was not authorized to speak publicly.
Cyclosporiasis is an intestinal infection contracted by consuming food, typically raw produce, or water contaminated with feces, according to the U.S. Centers for Disease Control and Prevention.
GOTTLIEB SAYS INVESTIGATION MATTERS MORE
Former FDA Commissioner Scott Gottlieb said on Monday that the false-positive result did not undermine the agency’s conclusions because investigators relied primarily on epidemiological evidence rather than laboratory testing.
“The particular test that tested positive that turned out to be a false positive was on recent samples. And so this isn’t the product that was affected – it went into the supply chain three weeks ago,” Gottlieb said.
Consumer foot traffic fell 18.9% at Taco Bell on Friday, compared with the day-of-week average between January 1 and July 6. Traffic at restaurant chains Chipotle and Cava was down 6.9% and 4.2%, respectively, on the same day, according to data from Placer.ai.
(Reporting by Ahmed Aboulenein and Yasmeen Abutaleb in Washington, Julie Steenhuysen in Chicago, Siddhi Mahatole and Neil J Kanatt in Bengaluru; Additional reporting by Leah Douglas in Washington; Editing by Maju Samuel, Pooja Desai and Daniel Wallis)
By Ahmed Aboulenein, Yasmeen Abutaleb and Julie Steenhuysen | Reuters | © Copyright Thomson Reuters 2026.
