Multi-State E. Coli Outbreak Linked to McDonald’s: What You Need to Know

The company says the likely source of an E. coli outbreak is slivered onions used on its Quarter Pounders.

A sign in front of a McDonald's restaurant in Pittsburgh on April 23, 2022. Gene J. Puskar/AP Photo

The U.S. Centers for Disease Control and Prevention (CDC) warned Tuesday that a multi-state outbreak of E. coli has been linked to McDonald’s Quarter Pounder hamburgers, leading to at least one death.

So far, the CDC said that 49 people from 10 states have been sickened with the E. coli O157:H7 strain, which can cause severe illness. Of that figure, 10 have been hospitalized and one person died.

Which States Are Affected?

Most of the E. coli cases have been reported in Colorado and Nebraska, which have 26 and 9 cases, respectively, the CDC said.

Cases have also been reported in Oregon, Montana, Wyoming, Utah, Kansas, Iowa, Missouri, and Wisconsin. Utah and Wyoming reported four cases each, while the other states have each only reported one case, according to the agency.

The CDC warned that the outbreak might not be limited to states that have reported illness so far and that the “true number of sick people is likely much higher than the number reported.” Some people recover from the bacterial infection without seeking medical care and aren’t tested, it said.

McDonald’s Responds

McDonald’s made some supply changes after the CDC sent out its food safety alert this week, including limiting the sale of Quarter Pounders temporarily in some states, the agency said.

In multiple states—Colorado, Kansas, Utah, Wyoming, and portions of Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, New Mexico, and Oklahoma—McDonald’s temporarily stopped using the slivered onions and the quarter-pound beef patties, the agency said.

Investigators are still working to investigate what ingredient in the Quarter Pounders was contaminated with E. coli, the CDC said, noting that “fresh slivered onions” are used on the burgers and not other McDonald’s menu items.

In a statement Tuesday, McDonald’s North America Chief Supply Chain Officer Cesar Pina said the outbreak is linked to the onions used on the Quarter Pounders.

“As a result, and in line with our safety protocols, all local restaurants have been instructed to remove this product from their supply and we have paused the distribution of all slivered onions in the impacted area,” the statement said. “We will continue to work with the Centers for Disease Control and Prevention and are committed to providing timely updates as we restore our full menu.”

Signs and Symptoms of E. Coli

Officials with the CDC and health experts say that symptoms of E. coli can start three to five days after ingesting the bacteria, including severe stomach cramps as well as diarrhea that can be bloody, vomiting, a low-grade fever, and a loss of appetite.

If the E. coli spreads outside the stomach, other symptoms can be present, according to the Cleveland Clinic. Should the bacteria infect the urinary tract, symptoms include pelvic or abdominal pain, pain or burning sensation when urinating, an urgent need to urinate frequently, and cloudy or foul-smelling urine.

The CDC says that individuals who suspect they may have contracted E. coli and have severe symptoms should contact a health care provider. Severe symptoms can include a fever of 102 degrees F or higher, diarrhea for more than three days that is not improving, bloody diarrhea, vomiting so much that liquids cannot be kept down, as well as signs of dehydration such as not urinating often, a dry mouth and throat, and feeling dizzy when standing.

A map released by the U.S. Centers for Disease Control and Prevention on Oct. 22, 2024, shows where the E. coli cases were reported. U.S. CDC

“Some people may develop serious kidney problems (hemolytic uremic syndrome, also called HUS) and would need to be hospitalized,” the CDC  warns.

Symptoms of HUS can include vomiting, bloody diarrhea, stomach pain, fever, chills, and headache, and later, people can experience fatigue, weakness, fainting, bruising, and paleness, officials say.

McDonald’s in the News Recently

The CDC alert was issued just two days after former President Donald Trump made a campaign stop at a McDonald’s location in Bucks County, Pennsylvania, where he worked the drive-through and fryer.

The former president’s campaign has since promoted the event, while Vice President Kamala Harris’s campaign has accused him of engaging in a publicity stunt.

In response, McDonald’s issued an email to its employees saying that it does not support any particular political candidate and that “we open our doors to everyone.” A McDonald’s franchise owner in Pennsylvania commissioned the Trump visit, the company said.