McDonald’s is facing questions over food safety after the Center for Disease Control on Tuesday tied an E. coli outbreak to Quarter Pounders, prompting the fast food giant to stop serving the burgers in a fifth of its restaurants.
According to the CDC, 49 people across 10 states became sick, and most of the affected consumers were from Colorado or Nebraska. The CDC said everyone they interviewed mentioned eating at McDonald’s before they felt ill, with most mentioning Quarter Pounders. Ten people were hospitalized and one individual died.
While the CDC didn’t specify an ingredient tied to the illness, it narrowed down its focus to fresh slivered onions and fresh beef patties. McDonald’s is focusing its investigation on the slivered onions used to make the toppings for its Quarter Pounder, with a company spokesperson noting during a Wednesday press briefing that those ingredients are sourced from a single supplier.
The onions are served raw, a McDonald’s spokesperson said. If confirmed to be the source of the outbreak, it would be the first time onions have been found to be a carrier of the strain of E. Coli in question.
McDonald’s supplier Taylor Farms on Wednesday moved to recall batches of raw onions due to potential E. Coli contamination, according to a notification from distributor U.S. Foods. The company told Bloomberg that it has yet to find traces of E. Coli, but issued a recall “out of an abundance of caution.”
While beef has not entirely been ruled out as cause of the outbreak, it’s less likely due to federal testing requirements and restaurant policies to cook meat at temperatures high enough temperatures to neutralize the bacteria. McDonald’s also sources beef in the affected area from multiple suppliers, a company spokesperson said.
The chain estimates that it served roughly 1 million Quarter Pounders from Sept. 27 through Oct. 11, the time frame in question, a company spokesperson said during a Wednesday press briefing. A McDonald’s spokesperson said it was not serving the Quarter Pounder in roughly 20% of its restaurants.
McDonald’s is working with its suppliers to replenish its Quarter Pounders in the near future with timing depending on the local market, Cesar Piña, McDonald’s chief supply chain officer for North America, said in a statement. All other beef products, including its Cheeseburger, Hamburger, Big Mac, McDouble and the Double Cheeseburger are not impacted and remain available.
Initial news of the outbreak sparked fears among investors, who compared this incident to Chipotle’s E. coli and norovirus outbreaks, which impacted several locations over three years and led to $25 million in fines in 2020. McDonald’s faced investor criticism as its stock price slid nearly 7% during the opening bell Wednesday, marking its worst day since March 12, 2020, according to CNN.