A recent Escherichia coli (E. coli) outbreak has been linked to McDonalds. The outbreak affected 90 people, who claimed they fell ill after eating the fast food restaurant’s quarter pound beef burgers, with 22 individuals hospitalized and only one fatality as of Oct. 30, 2024. The Center For Disease Control and Prevention (CDC) stated ingredients used in McDonalds’ quarter pound burgers were responsible for the E. coli outbreak which affected 13 states, including Missouri, Iowa and Colorado which have the highest number of cases.

E. coli is a bacterium found in contaminated food, water and in people and animals’ intestines. The McDonalds outbreak involved the O157H:H7 strain of E. coli, which releases a ‘Shiga’ toxin that disrupts protein synthesis in intestinal epithelial cells and leads to cell death, sloughing of the mucosa and eventually bloody diarrhea. According to the CDC it also leads to kidney failure, hemolytic uremic syndrome and other serious problems. Symptoms vary from fever, vomiting, dizziness and diarrhea and can take effect as early as the day of consumption to at least two weeks.

The Food and Drug Administration’s (FDA) preliminary investigations suggest uncooked slivered onions, supplied by Taylor Farms, are the likely source of the outbreak. The restaurant’s beef was unlikely to be contaminated due to the scrutiny with which the FDA inspects it to be approved for distribution. The onions supplied by Taylor Farms came from Colorado, where most of the cases have been recorded, which is why they are suspected to be the reason for this outbreak. These onions were distributed to approximately 900 McDonald’s restaurants. Taylor Farms have recalled all onions sold to food service customers in affected states including other fast food chains. FDA officials reassured the public that the risk of illness is low because all the onions have been recalled and should no longer be available.