Cyclospora outbreak cause identified: contaminated lettuce

FDA Links Shredded Iceberg Lettuce Supplied to Taco Bell to Cyclosporiasis Outbreak

The U.S. Food and Drug Administration has connected shredded iceberg lettuce from a single supplier in Mexico to 1,644 confirmed cases of cyclosporiasis among people who ate at Taco Bell restaurants in five states. The total number of confirmed cases nationwide stands at 1,645 as of July 13, according to the Centers for Disease Control and Prevention.

On July 17, the FDA stated that the lettuce was served at Taco Bell locations in Indiana, Kentucky, Michigan, Ohio, and West Virginia. A person familiar with the matter identified the supplier as Taylor Farms. The FDA did not name the company in its public update. The investigation remains active, and officials have not ruled out additional sources.

The CDC has recorded cases across 34 states since May 1. As of July 13, the agency reported 1,645 confirmed infections and 141 hospitalizations, with no deaths confirmed. Michigan state health authorities separately reported more than 4,300 cyclosporiasis cases in that state through early July, noting that their data include both confirmed and probable infections under state surveillance definitions.

Taylor Farms operates 30 processing facilities in North America and supplies salad greens to multiple restaurant chains and retailers, including Chipotle, McDonald’s, Costco, Walmart, and Trader Joe’s. The company did not respond to requests for comment. Its product recall page showed no active recalls as of early July 18.

Taco Bell issued a statement on July 17 stating that it had voluntarily removed the potentially affected lettuce from restaurants in the five states and was removing the ingredient from its national supply chain. The company said the replacement would occur within 24 hours in the affected states.

Cyclosporiasis is caused by the parasite Cyclospora cayetanensis. Symptoms typically begin about one week after exposure and include watery diarrhea, abdominal cramps, and gas. The illness can persist for several weeks without treatment. A combination antibiotic containing trimethoprim and sulfamethoxazole is the standard treatment. The CDC has stated that case counts may continue to rise through the end of August.

Health authorities have noted that Cyclospora is difficult to trace because of the incubation period and because the parasite’s genetic profile is more variable than those of bacteria such as E. coli or Salmonella. Previous outbreaks have been linked to various fresh produce items, including raspberries, snow peas, cilantro, and other leafy greens.

The FDA update specified that the contamination source was traced to one supplier of iceberg lettuce used by the affected Taco Bell locations. It is not yet determined whether other Taylor Farms products or other brands are involved. Consumers have been advised by some health experts to avoid pre-washed bagged salads during the current season, to select whole heads of lettuce, to discard outer leaves, and to wash produce thoroughly. No washing method has been shown to eliminate Cyclospora with certainty; cooking to an internal temperature of at least 158 degrees Fahrenheit inactivates the parasite.

Taylor Farms has been the subject of prior recalls. In 2024 the company recalled yellow onions distributed to McDonald’s and other outlets after an E. coli outbreak that caused one death and more than 100 illnesses across multiple states. In 2020 the company recalled onions sold at Kroger and Walmart because of potential Salmonella contamination. In 2025 it recalled certain salad kits that failed to declare soy and sesame allergens.

The current investigation continues to examine whether contamination occurred at the farm level through irrigation water or during washing at processing facilities. Amira Roess, professor of global health and epidemiology at George Mason University, stated that environmental water sources are the most common route of produce contamination with Cyclospora in regions where the parasite is present.

The CDC and FDA have not issued a nationwide consumer advisory specific to this outbreak beyond the actions taken by Taco Bell. State and local health departments continue to interview patients to identify any additional common food exposures.