Health officials are investigating an E. coli outbreak linked to McDonald’s Quarter Pounders in multiple states, the Centers for Disease Control and Prevention said Tuesday. It’s not yet known which ingredient in the hamburger is making people sick.
At least 49 people in 10 states have been sickened. One person, an older adult in Colorado, has died. Ten people have been hospitalized.
McDonald’s is working with public health officials to determine what ingredient is contaminated, according to the CDC. The fast-food chain has stopped using fresh slivered onions and quarter-pound beef patties in several states, the CDC said.
The first case occurred on Sept. 27. The CDC said that recent illnesses may not have been reported yet as “it usually takes 3 to 4 weeks to determine if a sick person is part of an outbreak.” Symptoms of E. coli infection include high fever, severe stomach cramps, diarrhea and vomiting.