A nationwide E. coli outbreak traced to McDonald’s Quarter Pounder burgers with slivered onions has now sickened at least 104 people across 14 states, according to an update from the Centers for Disease Control and Prevention (CDC) on Wednesday.
The outbreak, which led to at least one death and four severe cases of kidney failure, has raised concerns about food safety, even as McDonald’s resumed Quarter Pounder sales after sourcing slivered onions from a new supplier.
The CDC reported that the number of people hospitalized has risen to 34, with four individuals developing hemolytic uremic syndrome (HUS), a potentially life-threatening condition that affects the kidneys. Among the affected states, Colorado and Montana were hardest hit, with 30 and 19 cases respectively.
Federal health officials linked the outbreak to slivered onions provided by California-based Taylor Farms, which has since recalled the product. The US Food and Drug Administration (FDA) confirmed that an E. coli strain was found in one onion sample, though it did not match the strain responsible for this outbreak.
The CDC acknowledged that the actual number of cases may be higher than reported, as many people recover without medical care or testing for E. coli. The latest known case was reported on October 21.
McDonald’s, citing the FDA’s reassurance, resumed serving Quarter Pounders with slivered onions in about 900 restaurants that had previously halted sales due to the outbreak.
“There does not appear to be a continued food safety concern related to this outbreak at McDonald’s restaurants,” the FDA said in a statement.
In response, McDonald’s said it had “found an alternate supplier” for onions and has since reintroduced Quarter Pounders with slivered onions at the impacted locations.
The CDC initially issued a food safety alert in October, prompting McDonald’s to briefly halt sales of its Quarter Pounders with slivered onions. Although McDonald’s confirmed that beef patties were not implicated, Taylor Farms initiated a voluntary recall of their yellow onions following the outbreak. McDonald’s CEO Chris Kempczinski addressed the outbreak in a recent earnings call, expressing concern over the impact on customer trust and the company’s sales.
The CDC advises anyone who consumed McDonald’s Quarter Pounders and is experiencing symptoms of E. coli infection—including fever, stomach cramps, vomiting, and dehydration—to seek medical attention, especially young children who are at increased risk of severe kidney complications.
E. coli infections cause approximately 74,000 illnesses annually in the United States, leading to over 2,000 hospitalizations and 61 deaths, according to CDC data.
Forbes, the Associated Press, and CBS News contributed to this report.
