US fast-food chains were pulling fresh onions out of their menu items on Thursday after the vegetable was named as the likely source of an E. coli outbreak at McDonald’s restaurants that has sickened 49 people and killed one.
Restaurant Brands International, parent of McDonald’s rival Burger King, and Yum Brands said they were removing fresh onions from menu items. Roughly 5% of Burger King locations have removed onions from the menu, a Burger King spokesperson said in a statement.
McDonald’s said on Thursday that Taylor Farms was the supplier of the sliced onions that have been removed. Taylor Farms did not immediately respond to a request for comment. The company has recalled several batches of yellow onions produced in a Colorado facility, according to a recall memo on Wednesday by US Foods, one of the largest U.S. suppliers of food service operations.
About 5% of Burger King stores also get supplies from Taylor Farms, but a company spokesperson said Burger King has not been contacted yet from health authorities or had any illnesses. Yum, which operates KFC, Pizza Hut and the Taco Bell chains, said it was removing onions “out of an abundance of caution.”
The U.S. Food and Drug Administration on Thursday also confirmed that Taylor Farms was the supplier for the affected McDonald’s locations and that the company has initiated a voluntary recall.
“Yellow onions were sold to additional food service customers. Customers who received recalled onions have been directly notified of the recall,” an FDA spokesperson told Reuters.
Food distributors including US Foods and Sysco Corp have been notifying customers of the recall.
“Sysco has communicated to customers and a limited number of our sites instructions regarding the supplier-initiated recall of yellow onions,” a company spokesperson said.
The U.S. health regulator added that it was working with federal and state partners and the companies involved to investigate if onions are the source of this outbreak.
The U.S. Department of Agriculture said late on Wednesday that fresh onions were the likely source of the outbreak.
Past E. coli outbreaks have hampered sales at big fast-food restaurants as customers avoid the affected chains for fear of illness. Regulators are still investigating whether McDonald’s beef patties could be affected, but E. coli is killed in beef when cooked properly, whereas the McDonald’s Quarter Pounder is served with raw, slivered onions.
McDonald’s has pulled the Quarter Pounder from about one-fifth of its U.S. restaurants, including in Colorado, Kansas, Utah and Wyoming, and in parts of Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, New Mexico and Oklahoma.
“We’ve been told by corporate to not use any onions going forward for the foreseeable future,” Maria Gonzales, the on-duty manager inside a Burger King in Longmont, Colorado, said on Wednesday. “They’re off our menu.”
McDonald’s did not immediately respond to a request for comment on Thursday.