Tther fast-food restaurants - including Taco Bell, Pizza Hut, KFC and Burger King - pulled onions from some menus.
SALINAS, Calif. -- A California-based produce company was the source of fresh onions linked to a deadly E. coli food poisoning outbreak at McDonald's, officials with the restaurant chain said Thursday. Meanwhile, other fast-food restaurants - including Taco Bell, Pizza Hut, KFC and Burger King - pulled onions from some menus.
U.S. Foods, a major wholesaler to restaurants across the country, said Thursday that Taylor Farms had issued a recall this week for peeled whole and diced yellow onions for potential E. coli contamination. The recalled onions came from a Taylor Farms facility in Colorado, a U.S. Foods spokesperson said. But the wholesaler also noted that it wasn't a McDonald's supplier and that its recall didn't include any products sold at the fast-food chain's restaurants.
"Our records show that affected product may have been sent to your location. It is urgent that you stop using affected product as soon as possible," the recall notice read.
"US Foods takes food safety very seriously. Out of an abundance of caution, Taylor Farms, one of our third-party suppliers, has issued a voluntary recall for specific onion products produced out of their Colorado facility. The Taylor Farms recall impacts six US Foods distribution centers located in Colorado, Kansas, Nebraska and New Mexico. US Foods operates 70+ distribution centers across the country. As aligned with our rigorous recall process, we have contacted all impacted US Foods customers with appropriate recall instructions," the company said in a statement.
US Foods told ABC News that it does not distribute Taylor Farms slivered onions to McDonald's.
McDonald's confirmed in a statement to ABC News that Taylor Farms is the supplier of the sliced onions the fast-food chain removed, but it is unclear whether Taylor Farms provides its products directly to McDonald's or through an intermediary.
Four different products were included in the recall: 30-pound bags of peeled jumbo yellow onions, 4-5-pound bags of 3/8-inch diced fresh yellow onions, 5-pound bags of fresh diced yellow onions, and 6-5-pound bags of whole, peeled yellow onions.
"If you find any of the affected product, please record the number of cases and then destroy the product," the U.S. Foods notice stated.
Officials with the U.S. Food and Drug Administration did not confirm that the agency is investigating Taylor Farms. A spokesperson said Thursday that the agency is "looking at all sources" of the outbreak.
In the meantime, other national restaurant chains temporarily stopped using fresh onions.
"As we continue to monitor the recently reported E. coli outbreak, and out of an abundance of caution, we have proactively removed fresh onions from select Taco Bell, Pizza Hut and KFC restaurants," Yum Brands said in a statement.
Louisville, Kentucky-based Yum Brands wouldn't say where onions were removed or whether the company uses the same supplier as McDonald's. Yum Brands said it will continue to follow guidance from regulators and its suppliers.
Restaurant Brands International, which owns Burger King, said Thursday that 5% of its restaurants use onions distributed by Taylor Farms' Colorado facility. Burger King restaurants get deliveries of whole, fresh onions and its employees wash, peel and slice them.
Even though it wasn't contacted by health officials and it had no indications of illness, Restaurant Brands said it asked the restaurants that received onions from the Colorado facility to dispose of them two days ago. The company said it's restocking with onions from other suppliers.
Chipotle said Thursday it doesn't source onions from Taylor Farms or us any other ingredients from the Colorado facility.
Onions have been implicated in previous outbreaks. In 2015, Taylor Farms recalled a celery and onion mix used in Costco chicken salads after 19 people were sickened with E. coli. Last year, 80 people were sickened and one died in an outbreak of salmonella poisoning tied to bagged diced onions from Gills Onions of Oxnard, California.
As of the time of publication, the Centers for Disease Control and Prevention has reported 49 cases of E. coli with 10 hospitalizations and one death across 10 states linked to McDonald's Quarter Pounders.
Health officials have said they expect the number of sick people to grow.
"This is a fast-moving outbreak investigation. Most sick people are reporting eating Quarter Pounder hamburgers from McDonald's and investigators are working quickly to confirm which food ingredient is contaminated," the agency stated in a food safety alert. "McDonald's has pulled ingredients for these burgers, and they won't be available for sale in some states."
As a result, McDonald's removed the Quarter Pounder from menus in the states affected by the outbreak, which accounts for 20% of the U.S. locations.
McDonald's announced Wednesday that it had proactively removed two ingredients from stores across two impacted regions, but the company's leadership team assured that a majority of other menu items are not impacted, according to the CDC investigation.
"Other beef products at McDonald's, including the Cheeseburger, Hamburger, Big Mac, McDouble and the Double Cheeseburger, are not impacted," McDonald's USA president Joe Erlinger said Wednesday.
A spokesperson for McDonald's said either fresh onions, which came from one supplier, or beef patties used for the Quarter Pounder could be behind the outbreak.
If onions are found to be the source of the E. coli outbreak, it would be the first time onions have ever been a carrier for this particular strain of the bacteria, company spokespeople said on Wednesday.
The spokespeople also reiterated that onions used in the Quarter Pounders, as identified by CDC tracing data, came from suppliers that also test for E. coli.
Burger King released a statement Thursday saying, "There is no crossover with McDonald's for the vast majority of our onion facilities," but added, "About 5% of our restaurants do receive onions distributed from the Taylor Farms Colorado facility."
"Despite no contact from health authorities and no indications of illness, we proactively asked our 5% of restaurants who received whole onions distributed by this facility to dispose of them immediately two days ago and we are in the process of restocking them from other facilities," Burger King said.
A Greeley, Colorado, man is suing McDonald's after contracting an E. coli infection. In a lawsuit filed this week, Eric Stelly said he ate food from local McDonald's on Oct. 4 and fell ill two days later. After he sought emergency care, health officials confirmed his infection was part of the outbreak.
The Associated Press contributed to this report.