News CDC: McDonald’s Quarter Pounders Linked to Deadly E. Coli Outbreak in 10 States By Jenna Anderson Updated on October 24, 2024 Fact checked by Nick Blackmer Fact checked by Nick Blackmer Nick Blackmer is a librarian, fact-checker, and researcher with more than 20 years of experience in consumer-facing health and wellness content. health's fact checking process Close Michael M. Santiago / Getty Images An E. coli outbreak in 10 states linked to McDonald’s Quarter Pounders is currently being investigated, the CDC announced on Tuesday.There have been 49 reported illnesses connected to the outbreak—including 10 hospitalizations and one death—and the majority of cases occurred in Colorado and Nebraska.The contaminated ingredient is likely slivered onions, and McDonald’s has pulled Quarter Pounders off the menu in 12 states in response. An Escherichia coli (E. coli) outbreak in 10 states linked to McDonald’s Quarter Pounders is currently being investigated, the Centers for Disease Control and Prevention (CDC) announced on Tuesday. There have been 49 reported illnesses connected to the outbreak, including 10 hospitalizations. One older adult in Colorado has died, and another individual developed hemolytic uremic syndrome, which can lead to kidney failure, the CDC said. The number of reported cases is expected to rise, as it usually takes three to four weeks to determine whether an illness is part of a specific outbreak. The 49 illnesses were reported between September 27 to October 11, and the CDC’s investigation started on October 22. The majority of cases occurred in Colorado and Nebraska. It is still not known which ingredient in the Quarter Pounders is making people sick, the CDC said, but preliminary findings reviewed by the Food and Drug Administration (FDA) show that slivered onions could be a “likely source of contamination.” In a press release, McDonald’s said a number of the reported illnesses may be connected to onions “sourced by a single supplier that serves three distribution centers.” The company has asked restaurants in this affected area to stop using the slivered onions, as well as Quarter Pounder beef patties until officials figure out the source of the E. coli contamination. McDonald’s also said that it was temporarily removing the Quarter Pounder from restaurants’ menus in the impacted area, including Colorado, Kansas, Utah, and Wyoming, as well as certain regions of Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, New Mexico, and Oklahoma. Other beef menu items—such as the Big Mac and McDouble—are not impacted. “The decision to do this is not one we take lightly, and it was made in close consultation with the CDC,” said McDonald’s USA President Joe Erlinger in a video. “We are working quickly to return our full menu in these states as soon as possible.” 600+ Frozen Waffle Products Sold at Target, Walmart, and More Recalled Over Listeria Risk Which States Are Affected? The following states have reported cases of E. coli infection linked to the outbreak, listed by the number of illnesses: Colorado, 26Nebraska, 9Utah, 4Wyoming, 4Iowa, 1Kansas, 1Missouri, 1Montana, 1Oregon, 1Wisconsin, 1 Is E. Coli Contagious? Causes, Prevention, and Treatment How Serious Are E. coli Infections? The most common symptoms of an E. coli infection are diarrhea (which may be bloody) and stomach cramps. Symptoms typically start three to four days after consuming the bacteria and last for about a week. Most people recover from E. coli infections without the use of antibiotics. However, certain people have a higher chance of experiencing a more severe infection, including children under the age of five, adults 65 and older, and those with weakened immune systems. Severe symptoms might include: Diarrhea and a fever above 102°F Diarrhea for more than three days that is not improving, or bloody diarrhea Extreme vomiting that makes it hard to keep liquids down Signs of dehydration, such as not peeing, having a dry mouth or throat, or feeling dizzy Signs of hemolytic uremic syndrome, including decreased alertness, loss of color in the cheeks, unexplained bruising or tiny red spots on the skin, irritability, or blood in pee If you ate a McDonald’s Quarter Pounder and have severe E. coli symptoms, the CDC recommends contacting a healthcare provider. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit 6 Sources Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Centers for Disease Control and Prevention. E. coli outbreak linked to McDonald’s Quarter Pounders. Centers for Disease Control and Prevention. Investigation update: E. coli outbreak, McDonald's Quarter Pounders - October 22, 2024. Centers for Disease Control and Prevention. Where people got sick: E. coli outbreak, McDonald's Quarter Pounders - October 22, 2024. McDonald's. Always putting food safety first. Centers for Disease Control and Prevention. Treatment of E. coli infection. Centers for Disease Control and Prevention. E. coli infection (Escherichia coli): signs of hemolytic uremic syndrome.