(CNN) — The US Centers for Disease Control and Prevention issued a food safety alert Tuesday regarding an E. coli outbreak that it says is linked with McDonald’s Quarter Pounders.
At least 49 illnesses have been reported across 10 states, including one death of an older person. Ten people have been hospitalized, including a child who had hemolytic uremic syndrome, a serious complication that can develop from an E. coli infection. Most of the illnesses are in Colorado and Nebraska.
Most of the people who became ill reported eating McDonald’s Quarter Pounder sandwiches, the CDC says.
The agency says that the investigation is “fast-moving” and that information reviewed by the US Food and Drug Administration shows that slivered onions are a likely source of contamination.
McDonald’s has stopped using the onions as well as quarter-pound beef patties in several states while the investigation continues, the CDC says. According to the agency, the beef patties are used only for the Quarter Pounders, and the slivered onions are used primarily for the Quarter Pounder and not other items.