McDonald’s E. coli Outbreak Linked to Onions in Quarter Pounders

The cases appear to be linked to the restaurant’s infamous Quarter Pounders—more specifically, the slivered onions featured on the burgers, according to an update from McDonald’s Wednesday, October 23.

“The initial findings from the investigation indicate that a subset of illnesses may be linked to slivered onions used in the Quarter Pounder and sourced by a single supplier that serves three distribution centers,” McDonald’s states in its update. “As a result, and in line with our safety protocols, all local restaurants have been instructed to remove this product from their supply and we have paused the distribution of all slivered onions in the impacted area.”

As a precaution, the Quarter Pounder will also be removed from the menu in the affected areas until all investigations are complete. The impacted area in question appears to be limited to 12 states: Colorado, Kansas, Utah, Wyoming, Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, New Mexico and Oklahoma.

E. coli, or Escherichia coli, is a bacteria that lives in the gut of healthy people. Under normal circumstances, it can help digest food and its presence is generally inconsequential. However, when ingested, certain strains of E. coli can cause infections that are accompanied by uncomfortable GI issues, including diarrhea, severe stomach pain and vomiting. If these issues persist, they can lead to dehydration. In the worst cases, E. coli can cause sepsis—a serious, potentially deadly infection of the blood.

The symptoms usually show up within a few days of eating, drinking, or coming into contact with something contaminated by the bacteria, though some strains can make you feel sick within hours. E. coli can be spread, but not through coughing or sneezing. It most often spreads to individuals caring for someone with the bacteria through contact with their poop or other objects the bacteria may be on, which is why sanitizing surfaces and washing hands are extremely important to limit its spread.

People who have contracted E. coli often do not need any treatment as long as they are staying hydrated. However, in more severe cases, doctors will sometimes prescribe antibiotics.