• A multi-state E. coli outbreak has been linked to McDonald’s Quarter Pounder burgers.
• 49 people in 10 states have become ill and one person has died.
• Those who have eaten one and experienced severe E. coli symptoms should call their healthcare provider, the CDC said.

McDonald’s Quarter Pounder burgers have been linked to 49 cases of E. coli infections and one death during an outbreak in ten states. The Centers for Disease Control and Prevention said anyone who has developed severe E. coli symptoms after eating a Quarter Pounder should call their healthcare provider.

The last case of E. coli linked to the outbreak was recorded on October 11, according to the Food and Drug Administration. Symptoms of an E. coli infection usually occur three to four days after someone swallows the bacteria, according to the CDC.

According to the CDC, symptoms of a serious E. coli infection include:

• Bloody diarrhea or diarrhea that lasts more than 3 days and does not improve
• A fever higher than 102°F
• Vomiting and being unable to keep fluids down
• Severe stomach cramps
• Signs of dehydration, including: feeling dizzy when standing, dry mouth and throat, and not urinating much

Most people with typical E. coli symptoms recover within five to seven days without medical treatment, the CDC said, but some people may develop serious kidney problems and require hospitalization.

Ten people have been hospitalized after eating Quarter Pounders

As of Tuesday, the outbreak had been linked to 10 hospitalizations, with most illnesses occurring in Colorado and Nebraska, the CDC said.

Public health officials are investigating what ingredient could be causing the outbreak, but early information from the FDA suggests that the sliced ​​onions or beef patties used for Quarter Pounders are the likely source of contamination.

Cesar Piña, McDonald’s chief supply chain officer for North America, said in a statement on his website Tuesday that initial investigation suggested the illnesses may be linked to cut onions, which came from a single supplier serving three distribution centers.

McDonald’s has stopped using both the beef patties and sliced ​​onions specifically used for the Quarter Pounder. It has also temporarily removed the burger from menus in Colorado, Kansas, Utah and Wyoming, as well as parts of surrounding states such as Nebraska and Oklahoma.

The FDA said Tuesday that diced onions and other types of beef patties used in McDonald’s restaurants are not affected by the E. coli outbreak.

McDonald’s stock price fell more than 9% as news of the outbreak spread. John A. Gordon, a chain restaurant analyst, told Business Insider on Tuesday that sales of the Quarter Pounder could be negatively affected.

McDonald’s did not immediately respond to a request for comment from Business Insider after business hours.

Have you experienced complaints of E. coli after eating at McDonald’s? Contact reporter Serafina Kenny: [email protected].