FDA traces cyclospora outbreak to Mexican lettuce supplier used by Taco Bell

Federal health investigators have traced a sprawling cyclospora outbreak to a single source: iceberg lettuce from Mexico supplied to Taco Bell locations across five states. The Centers for Disease Control and Prevention issued the warning late Thursday, advising consumers to avoid shredded iceberg lettuce from Taco Bell restaurants in Indiana, Kentucky, Michigan, Ohio, and West Virginia. The parasite, which causes severe watery diarrhea, has sickened thousands across the country in what has become the largest documented cyclospora outbreak in US history.

The FDA's traceback investigation pinpointed the supplier, though federal officials initially withheld the company name. Taylor Fresh Foods, based in Salinas, California, subsequently acknowledged that FDA testing had identified "a specific independent farm" affiliated with the company as the source. The company announced Friday that it was voluntarily removing all iceberg lettuce sourced from central Mexico from the US market. Taco Bell, for its part, committed to halting use of lettuce from the identified supplier and said it would replace the affected ingredient nationwide within 24 hours in the hardest-hit states.

The scale of illness is staggering. Michigan, which appears to be the outbreak's epicenter, has reported more than 5,000 confirmed cases, with an additional 2,000 probable and suspected cases scattered across other states. More than 100 people in Michigan have required hospitalization, and dozens more have been admitted to hospitals in other affected areas. No deaths have been reported, but the sheer volume of cases has overwhelmed public health systems. The current surge has already far exceeded the previous US record, set in 2019, when approximately 4,700 cyclospora cases were reported nationwide.

Cyclospora is a microscopic parasite that infects the intestines and spreads through feces-contaminated water. The illness, called cyclosporiasis, typically causes explosive diarrhea and is usually treatable with antibiotics. Outbreaks tend to cluster in late spring and summer, when the heat-loving parasite thrives. In past incidents, people have contracted the infection by consuming fruits or vegetables exposed to contaminated irrigation water. The parasite is far less common than other foodborne pathogens like salmonella or E. coli, and for years, few US cases were documented. But the trend has shifted dramatically over the past decade, with a particularly sharp spike around 2018 and 2019.

Public health officials have stressed that the investigation remains ongoing and that other restaurants, retailers, or distribution channels could be implicated as the outbreak continues to unfold. Michigan investigators are actively examining whether the contaminated lettuce reached establishments beyond Taco Bell, noting that many ill people reported no consumption at the chain. State health officials have found no evidence of poor food handling or preparation at any single restaurant, suggesting the contamination originated upstream in the supply chain. They continue to recommend that consumers purchase whole heads of lettuce rather than pre-washed, bagged varieties or pre-mixed salad kits.

Taylor Fresh Foods has a history with foodborne outbreaks. The company was linked to a 2013 cyclosporiasis outbreak tied to salad mix and a 2024 E. coli outbreak connected to onions served at McDonald's. The company's statement Friday acknowledged the gravity of the situation, expressing deep concern for those who fell ill and for consumers whose trust in fresh produce safety has been shaken. Taco Bell, too, has been tied to foodborne illness outbreaks in the past, though the chain moved quickly to contain this one.

Experts attribute the rising trend in cyclospora cases to a combination of factors: climate change creating conditions favorable to the parasite, improved detection methods that catch cases previously missed, and the likelihood that historical cases were significantly underreported. The parasite cannot be grown in laboratory settings, making it difficult to isolate from contaminated produce. Many standard food poisoning tests were not designed to detect cyclospora, meaning cases went undiagnosed. Additionally, tracing the source becomes complicated when a single ingredient—like basil, cilantro, or lettuce—appears in multiple recipes across different establishments.

As investigators continue their work, the outbreak serves as a stark reminder of how vulnerable the nation's fresh produce supply remains, and how quickly a single contaminated shipment can sicken thousands across multiple states. The question now is whether other businesses received lettuce from the same supplier, and whether the true scope of this outbreak extends beyond what has been documented so far.