Start date of the investigation: October 22, 2024

Investigation status: Open

Callback issued: Yes

New from October 25th: Additional illnesses were reported and all respondents continue to report that they ate at McDonald’s before the illness began. The most recent illness began on October 10th. Taylor Farms has initiated a voluntary recall of some onions shipped to food service providers. Based on product actions taken by both companies, CDC believes the risk to the public is very low.

United States

  • cases: 75 (26 new)
  • Hospital stays: 22 (12 new)
  • Deaths: 1 (0 new)
  • States: 13 (3 new)

New from October 25th: Additional illnesses were reported and all respondents continue to report that they ate at McDonald’s before the illness began. The most recent illness began on October 10th. Taylor Farms has initiated a voluntary recall of some onions shipped to food service providers. Based on product actions taken by both companies, CDC believes the risk to the public is very low.

Summary of the situation

CDC, FDA, USDA FSIS and public health officials in several states are investigating an outbreak of E.coli O157:H7 infections. Most people in this outbreak report eating the Quarter Pounder hamburger at McDonald’s before getting sick. It is not yet known which specific food ingredient is contaminated.

McDonald’s is working with research partners to find out which food ingredient in Quarter Pounders is making people sick. McDonald’s has stopped using fresh onion slices and quarter-pound beef patties in several states while the investigation to identify the disease-causing ingredient continues.

Taylor Farms, the supplier of sliced ​​onions to the affected McDonald’s locations, has initiated a voluntary recall and asked customers to stop using onions while the investigation is ongoing. Restaurant customers were contacted directly and asked to remove the onions.

Contaminated food

McDonald’s Quarter Pounder Hamburgers make people sick

  • Quarter Pounder hamburgers will be temporarily unavailable in some states while McDonald’s makes some offering changes.
  • McDonald’s locations in Colorado, Kansas, Utah, Wyoming and parts of Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, New Mexico and Oklahoma have temporarily stopped using their current offerings of Quarter Pounder onions and beef patties.
  • McDonald’s is proactively making these changes while investigators work to confirm the contaminated ingredient. Quarter pound beef patties are only used at Quarter Pounders. Fresh onion slices are primarily used for Quarter Pounder hamburgers and not for other menu items.
  • Investigators are working to find out what ingredient in these hamburgers is making people sick and whether it made its way into other restaurants or stores.

What you should do

McDonald’s has stopped using fresh onion slices and quarter-pound beef patties in several states to protect its customers while a source of illness is confirmed.

Call your doctor if you have a serious illness E.coli Symptoms:

  • Diarrhea and fever over 38°C
    • Diarrhea for more than 3 days that is not improving
    • Bloody diarrhea
  • Vomiting so much that you can’t keep your fluids down
  • Signs of dehydration, such as:
    • Not peeing much
    • Dry mouth and throat
    • Feeling dizzy when standing up

What companies should do

  • Food service operators should not sell, eat, or serve the yellow onions recalled by Taylor Farms.
  • Taylor Farms contacted the companies directly.

Symptoms of E.coli

  • Most people are infected with Shiga toxin E.coli suffer from severe stomach cramps, diarrhea (often bloody) and vomiting.
    • Symptoms usually begin 3 to 4 days after ingesting the bacteria.
    • Most people recover without treatment in 5 to 7 days.
  • Some people may develop severe kidney problems (hemolytic uremic syndrome, also called HUS) that require hospitalization.
  • More information about E.colisee info Escherichia coli Infection page



Content source:

National Center for Emerging and Zoonotic Infectious Diseases (NCEZID)