McDonald's shares fall after CDC says E. coli outbreak linked to Quarter Pounders

McDonald's Stocks fell in extended trading Tuesday after the Centers for Disease Control and Prevention said an E. coli outbreak linked to McDonald's Quarter Pounder burgers led to 10 hospitalizations and one death.

The agency said 49 cases were reported in 10 states between Sept. 27 and Oct. 11, with most illnesses occurring in Colorado and Nebraska. “Most” sick people reported eating a McDonald's Quarter Pounder, the CDC added.

One of the patients developed hemolytic uremic syndrome, a serious condition that can lead to kidney failure. An older adult in Colorado has died.

Shares of McDonald's fell about 7% in after-hours trading on Tuesday.

In a statement Tuesday, McDonald's said it was taking “swift and decisive action” following the E. coli outbreak in certain states.

The company said initial results from the ongoing investigation show that some of the illnesses may be linked to slivered onions – or fresh, thinly sliced ​​onions – used in the Quarter Pounder and purchased from a single supplier that serves three distribution centers . McDonald's has ordered all local restaurants to remove sliced ​​onions from their inventory and has stopped distributing the ingredient in the affected area.

Quarter Pounder hamburgers will be temporarily unavailable in several Western states, including Colorado, Kansas, Utah and Wyoming, as well as parts of other states, McDonald's said. It added that it was working with suppliers to replenish ingredients.

Most states and menu items are unaffected by the outbreak, Joe Erlinger, president of McDonald's USA, said in a video. The company's other beef products, including cheeseburgers, hamburgers, Big Mac, McDouble and the double cheeseburger, are not affected, he added. These sandwiches use a different type of onion product.

“We are working quickly to return our full menu in these states as quickly as possible,” Erlinger said. “I hope these steps demonstrate McDonald’s commitment to food safety.”

Quarter Pounder hamburgers are a key menu item for McDonald's, bringing in billions of dollars each year. In 2018, McDonald's introduced fresh beef for its Quarter Pounders in most of its U.S. stores.

The CDC said the number of people affected by the outbreak is “likely much higher” than previously reported. The agency said that's because many people recover from an E. coli infection without being tested for it or receiving medical care. Additionally, it typically takes three to four weeks to determine whether a sick patient is part of an outbreak, the CDC added.

E. coli refers to a group of bacteria that occurs in the intestines of almost all people and animals. However, some strains of bacteria can cause mild to severe illness when a person eats contaminated food or drinks contaminated water.

According to the CDC, symptoms such as stomach cramps, diarrhea and vomiting usually appear three to four days after ingesting the bacteria. Most people recover without treatment in five to seven days.

Several cases of E. coli have been reported in McDonald's restaurants in the past.

In 2022, at least six children developed symptoms suggestive of E. coli poisoning after eating McDonald's Chicken McNuggets Happy Meals in Ashland, Alabama. Four of the six children were hospitalized due to serious side effects.