The FDA and CDC say Michigan health officials analyzed food exposure details from 190 of the cases who reported eating at Taco Bell and shared these findings with CDC. Ingredient-level analyses on meals eaten by these cases indicate that 90% of those interviewed reported eating iceberg lettuce.

The FDA’s traceback investigation has identified a single supplier of iceberg lettuce from Mexico used by Taco Bell locations where people ate before becoming ill. While the FDA did not publicly identify the supplier, the agency says it is working directly with the supplier to determine if potentially contaminated shredded iceberg lettuce remains on the market. 

As part of this investigation, the FDA and state partners have initiated collection of product samples for testing and analysis. Additionally, the agency says it has increased screening at the border for products implicated in the outbreak.

Taco Bell says it has taken action to remove potentially impacted lettuce from a supplier in select states. 

“The affected ingredient from our supplier is being indefinitely removed from our supply chain nationwide and will be replaced within 24 hours in select states,” the chain said in a statement.

Because the investigation remains ongoing, the FDA says additional implicated brands, restaurants, retailers or distribution channels may be identified as the investigation continues. This advisory will be updated promptly as new information becomes available.