Why It Matters
The FDA’s correction of a false positive cyclospora test does not halt the investigation into an outbreak that has sickened more than 1,600 people across five states. The agency’s acknowledgment underscores the distinction between a laboratory error and the broader epidemiological evidence linking Taylor Farms iceberg lettuce to severe gastrointestinal illness.
What Happened
The FDA announced that a sample of iceberg lettuce from Taylor Farms’ central Mexico facility initially tested positive for cyclospora parasite on Saturday, but subsequent quality checks determined the result was a false positive. The discovery came after laboratory experts found no true amplification of the parasite in the sample, leading the agency to reverse its earlier finding.
Taylor Farms had issued a voluntary recall of iceberg lettuce products from the Mexican facility following the initial positive test. The company noted that the FDA had informed it of the mistaken result, though the agency later clarified it had not issued a formal apology but rather explained the factual circumstances of the error.
As of Sunday, no confirmed samples of Taylor Farms lettuce have tested positive for cyclospora. The false positive sample was not part of the current recall advisory.
Acting FDA Commissioner Kyle Diamantas emphasized that the laboratory error does not alter the agency’s investigation trajectory. “I want to stress that our investigation continues, including into other potential sources and commodities for other clusters of illnesses,” Diamantas said.
Shredded lettuce from Taylor Farms sold in Taco Bell restaurants remains identified as a potential outbreak source. The outbreak has concentrated in the Great Lakes and Appalachian regions, with cases confirmed in Michigan, Ohio, Indiana, Kentucky, and West Virginia.
By the Numbers
1,644 — confirmed cases of cyclosporiasis linked to the outbreak, according to the CDC
94 — hospitalizations recorded
0 — deaths reported
5 — states with confirmed cases
Zoom Out
Cyclospora outbreaks linked to fresh produce have recurred regularly over the past two decades, often traced to imported lettuce and leafy greens from Mexico and Central America. The pathogen, a parasitic protozoan, causes severe watery diarrhea and other gastrointestinal symptoms that typically resolve without treatment but may require hospitalization in severe cases. Food testing for cyclospora remains technically challenging, with false positives occasionally occurring in laboratory settings—a reality the FDA’s quality control process has now illustrated.
The outbreak underscores ongoing supply-chain vulnerabilities in the fresh produce system, where contamination at a single facility can rapidly distribute products across multiple states and restaurant chains. Regulatory agencies continue to balance rapid response to illness clusters with the need for confirmed laboratory results before public guidance.
What’s Next
The FDA stated its investigation continues into other potential sources and commodities related to additional illness clusters. The recall advisory remains in effect, with the agency’s banner warning consumers: “Do not eat recalled iceberg lettuce from Taylor Farms de Mexico.” Consumers who have purchased the recalled product are advised to discard it or return it to the point of purchase. The CDC last updated its outbreak tracking webpage on Saturday and is expected to provide updated case counts as state health departments report new findings.