US health officials have traced a nationwide outbreak of cyclosporiasis, a parasitic infection causing "explosive diarrhoea", to iceberg lettuce supplied by Taylor Farms, which supplies Taco Bell. The Food and Drug Administration confirmed a positive sample came from lettuce sourced in central Mexico, but the affected batch falls outside the recall Taylor Farms had already voluntarily issued on Friday, meaning officials are now checking whether any of the implicated product remains in shops or homes. The outbreak matters because it has caused widespread illness across multiple US states and highlights gaps in tracing contaminated produce through the food supply chain.

At least 94 people have been hospitalised, though no deaths have been reported, since the infections were first detected on 13 May. The Centers for Disease Control and Prevention has urged people not to eat shredded iceberg lettuce from Taco Bell outlets in Indiana, Kentucky, Michigan, Ohio and West Virginia, while Taylor Farms lettuce was recalled across 27 states and Marketside-branded lettuce sold at Walmart was recalled in 15 states. Taco Bell says it has removed all affected lettuce from its restaurants, and Taylor Farms says it has stopped receiving product from the implicated batch and is working with federal and state authorities.