Onions Recalled in Deadly E.Coli Outbreaks Linked to McDonald’s Quarter Pounders

The deadly outbreak spurred removal of onions by a major food supplier in the Mountain West. Taco Bell, KFC and Pizza Hut have stopped serving onions with their menu offerings at various locations.

A sweeping onion recall related to a multistate E. coli outbreak linked to McDonald’s Quarter Pounders has prompted several other major food chains to remove raw onions from their menu offerings.

Taco Bell, Pizza Hut and KFC have stopped adding fresh onions to their signature items at certain locations “out of an abundance of caution,” according to a spokeswoman from Yum Brands, which owns those chains. Yum Brands would not elaborate or say how many sites in how many states would not offer onions.

Though federal regulators have not confirmed the source of the outbreak, which has so far killed one person and sickened 49, initial investigations have suggested that the fresh, slivered onions served mainly atop the Quarter Pounder were a “likely source of contamination.”

Taylor Farms, the sole supplier of those onions to the affected McDonald’s locations in 10 states, issued a recall of several yellow onion products because of “potential E. coli contamination,” according to a notice from U.S. Foods, a company that distributes the Taylor ingredients to many restaurants.

Yum Brands declined to say whether Taylor Farms supplied its onions. In addition, though U.S. Foods alerted its customers, a spokeswoman said it did not directly supply McDonald’s with Taylor onions. McDonald’s declined to publicly identify its distributors.

The U.S. Foods notice instructed restaurants to immediately stop serving the specified onions — diced, peeled and whole — and destroy them.

The items were voluntarily recalled by Taylor Farms Colorado out of an “abundance of caution,” a spokeswoman for U.S. Foods said in an email. Taylor Farms did not immediately respond to requests for comment.

McDonald’s and the Food and Drug Administration said preliminary reviews linked the outbreak to those raw, slivered onions. But health officials and McDonald’s said that they had not ruled out possible contamination of the quarter-pound beef patties used for the burger, a popular menu item. The Agriculture Department said a state agency has collected ground beef patties for testing. The Centers for Disease Control and Prevention is also investigating reports from people who became ill in a number of states.

The outbreak has sickened people across the Mountain West, though most cases have been clustered in Colorado.

Sysco, one of the largest food distributors in the United States, has also notified its customers of the onion recall, a spokesman for the company said. McDonald’s is not a Sysco customer.

McDonald’s has stopped using slivered onions, and has halted sales of Quarter Pounders at restaurants in Colorado, Kansas, Utah, Wyoming, Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, New Mexico and Oklahoma. McDonald’s has said that its other hamburger items are not affected by the recall.

One lawsuit has already been filed on behalf of at least 10 people who say they were sickened by McDonald’s food, including one Colorado man who said he went to the emergency room after eating at his local McDonald’s.

E. coli outbreaks are not uncommon in the United States, said Barbara Kowalcyk, director of the Institute for Food Safety and Nutrition Security at George Washington University.

Every year, there are 20 to 50 E. coli outbreaks, a spokeswoman for the C.D.C. said. In 2024 alone, 13 cases have been linked to organic walnuts and 11 cases were linked to raw Cheddar cheese.

In 2019, a large E. coli outbreak linked to romaine lettuce grown in the Salinas Valley region of California sickened 167 people in 27 states, including 85 who were hospitalized. Taylor Farms did not issue a recall during the outbreak, but acknowledged in 2019 that research suggested that irrigation water was the source of the contamination.

Experts have found that open creeks used to water fields can be littered with feces from wild animals and larger-scale cattle ranches and other farms. At the time, Taylor Farms company pledged to buy leafy greens only from growers that killed bacteria by treating their irrigation water.

The F.D.A. finalized a rule last year on how water should be managed on farms that grow produce, but did not require routine treatment of irrigation water. Instead, the rule calls on farmers to assess the risks unique to their farm and take steps to minimize them.

What worries experts about this outbreak is that this particular strain of the bacteria can cause a life-threatening condition called Hemolytic Uremic Syndrome, which damages blood vessels in the kidneys.

The condition is most common in young children and there is no treatment to stop the disease from progressing once it has started. Federal health officials said one of the people hospitalized with the disease was a child. Of the 49 people with a confirmed case of E. coli, the youngest was 13.

“If you had to pick the characteristics you would not want to have in your food-borne disease group, this is a good set,” said Dr. Michael Osterholm, an infectious disease expert at the University of Minnesota.

One silver lining of this outbreak, Dr. Kowalcyk said, is that parents don’t generally buy the large hamburgers for young children.

Dr. Osterholm said that while beef used to be a frequent source of E. coli outbreaks (dangerous strains of the bacteria often live in cow intestines), several high-profile outbreaks have led to food safety changes that have made beef less likely to be a culprit.

For example, after an E. coli outbreak in 1993 related to undercooked Jack in the Box hamburger patties — which sickened hundreds, killed four children and left others with kidney failure — the F.D.A. raised the recommended internal temperature for hamburgers.

Historically, a large proportion of food-borne illnesses has proved impossible to trace back to the source. A study by federal officials looking at more than 3,800 clusters of E. coli, salmonella and listeria illnesses found that about 40 percent of the cases could not be linked to a particular food.

The study examined outbreaks from 1998 through 2021, though, before whole genome sequencing became commonplace in food-safety investigations.

Sequencing provided a breakthrough to inspectors investigating a recent cluster of 10 listeria-related deaths and dozens of illnesses linked to Boar’s Head deli meats. Public health inspectors in Maryland and New York found the strain of listeria in packaged liverwurst that matched bacteria from hospitalized patients.

The F.D.A., which oversees fresh produce, has said that it is looking at all sources of possible E. coli contamination as the Quarter Pounder investigation rapidly develops.

Taylor Farms has also faced federal scrutiny in recent years over violations of the Clean Air Act related to its handling of the anhydrous ammonia it uses for refrigeration in some of its food processing facilities. The gas was released at a Rhode Island facility after a forklift hit a storage container. The Environmental Protection Agency fined the company $650,000 in 2023 over the violation.

The company paid a $67,000 fine from the E.P.A. in 2018 over releasing pollutants into a local waterway near its plant in Salinas, Calif.

Christina Jewett contributed reporting.

Food Safety Issues and How to Avoid Them

• Listeria: A listeria outbreak has been linked to Boar’s Head deli meats, leading to a recall of seven million pounds of the company’s products. Here’s what to know.
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