What happened in 5 previous outbreaks of foodborne illnesses at restaurant chains

Federal health officials have identified iceberg lettuce served at Taco Bell locations across five states as the source of a widespread outbreak of infections caused by the parasite cyclospora. The parasite is known to cause diarrhea. An investigation by the U.S. Food and Drug Administration pinpointed a single supplier as the origin of the suspect lettuce.

Taco Bell announced Thursday that the affected ingredient from its supplier is being removed from its supply chain nationwide and will be replaced within 24 hours in select states. The company described the move as a precautionary measure. A federal official briefed on the investigation identified the supplier as Taylor Farms, a California-based company that produces fresh vegetables for commercial use, meal kits, and bagged lettuce sold in supermarkets. Health officials stressed that other brands, restaurants, retailers, or distribution channels could be implicated as the investigation progresses.

This incident adds to a history of foodborne illness outbreaks linked to major U.S. restaurant chains. In 2024, raw onions on McDonald's Quarter Pounder hamburgers, also supplied by Taylor Farms, were implicated in an E. coli outbreak that sickened at least 104 people in 14 states, resulting in 34 hospitalizations and one death. McDonald's temporarily removed the Quarter Pounder from its menu in affected areas.

Wendy's also faced scrutiny in August 2022 when it pulled lettuce from sandwiches in Michigan, Ohio, and Pennsylvania due to potential E. coli contamination. The CDC investigated whether romaine lettuce was the source of an outbreak that sickened at least 37 people. Chipotle experienced a significant E. coli outbreak in 2015 that affected over 50 people and led to temporary restaurant closures on the West Coast. These past events highlight the ongoing challenges in food safety regulation within the restaurant industry.