The CDC says the E. coli outbreak at McDonald's is over

In this photo illustration, a McDonald's Quarter Pounder hamburger meal is seen at a McDonald's in the Flatbush neighborhood of the Brooklyn borough of New York on October 23, 2024.

Michael M. Santiago | Getty Images

The Centers for Disease Control and Prevention announced Tuesday that the deadly E. coli outbreak is linked to cut onions McDonald's is over, more than a month after the agency began investigating the spread.

According to the CDC, the outbreak infected 104 people in 14 states. It resulted in 27 hospitalizations and one previously reported death of an older adult in Colorado.

The agency first announced the outbreak on Oct. 22. The CDC indicated that freshly sliced ​​onions served on Quarter Pounders and other menu items were the likely cause of this outbreak.

Quarter Pounder hamburgers are a key menu item for McDonald's, bringing in billions of dollars each year. The company temporarily removed these burgers from some locations following the outbreak, but has since reintroduced the menu item. The most recent outbreak occurred on October 21, the day before the company took action and the CDC announced its investigation.

Even though the outbreak is officially over, McDonald's is still struggling with lost sales.

According to a research note from Gordon Haskett, foot traffic to its U.S. restaurants fell 6.6% as of Nov. 18 compared to a year ago. That's an improvement from the low point of a seven-day rolling average of 11% traffic declines on Oct. 29.

The 10 states that the CDC first linked to the outbreak saw larger drops in traffic, such as a combined decline of 9.5% on Nov. 18, according to the release.

Additionally, the company will invest more than $100 million in marketing and targeted financial support for affected franchisees.

McDonald's has brought back its popular McRib starting Tuesday, despite a “farewell tour” last year. The chain will also introduce a new McValue menu in January, hoping to appeal to consumers looking for value deals.

“Looking forward, we must remain focused on regaining our customers’ hard-earned trust and revitalizing their brand affinity,” Michael Gonda, McDonald’s North American chief impact officer, and Cesar Pina, the company’s North American chief supply chain officer, wrote in an internal Memo on Tuesday.

McDonald's shares have fallen 7% since the CDC first linked the chain's Quarter Pounders to the outbreak. The company has a market capitalization of $209.6 billion.