WASHINGTON D.C. (Michigan News Source) – After weeks of searching for the source of Michigan’s growing cyclosporiasis outbreak, federal investigators believe they’ve found a major breakthrough. The U.S. Food and Drug Administration (FDA) traced a five-state Cyclospora outbreak to shredded iceberg lettuce served at Taco Bell restaurants. The traceback investigation led investigators to Taylor Farms de Mexico, which has since recalled all iceberg lettuce sourced from central Mexico that was distributed to restaurants, food-service companies and retailers in 27 states, including Michigan.

The FDA’s traceback investigation identified Taylor Farms de Mexico as the common supplier of the implicated shredded iceberg lettuce, prompting the company to voluntarily recall affected products distributed to 27 states, including Michigan. The FDA is responsible for tracing contaminated food through the supply chain and coordinating recalls, while the Centers for Disease Control and Prevention (CDC) tracks illnesses, analyzes patient data, and works with state health officials to determine how outbreaks are spreading. Federal investigators are also investigating other outbreaks and illnesses of cyclosporiasis nationally that are unrelated to this outbreak.

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Recall follows illnesses across five states.

The cyclosporiasis outbreak has sickened at least 5,002 people in Michigan, with 102 people hospitalized, according to Reuters citing Michigan health officials. Among 190 Michigan patients who reported eating at Taco Bell and were interviewed about their meals, 90% reported eating iceberg lettuce, according to the FDA

Taylor Farms said it is removing all iceberg lettuce sourced from central Mexico from the U.S. market. Recalled products were distributed between June 29 and July 16 across 27 states, including Michigan, under several retail and food-service labels. Consumers are being told to throw the products away rather than gamble on whether their salad comes with an unwanted microscopic topping.

The FDA said its traceback investigation converged on Taylor Farms de Mexico as the single supplier providing shredded iceberg lettuce to Taco Bell locations where sick customers had eaten. Taco Bell has agreed to stop using the implicated lettuce, although not every location in the affected states received it.

The FDA has also released a statement saying that a test after the recall suggested Taylor Farms de Mexico lettuce contained Cyclospora was a false positive. After reviewing the results, agency experts determined the sample that was provided by Taylor Farms de Mexico did not actually test positive for the parasite and removed that information from its July 18 update. The FDA said it has notified Taylor Farms, continues working to remove potentially affected products from the market, and is still testing lettuce samples. As of July 19, no Taylor Farms product samples have been confirmed positive for Cyclospora. Federal officials are continuing to investigate other Cyclospora outbreaks and have not concluded that all cases stem from the same source.