In an effort to determine the offending ingredient, McDonald’s told the CDC it has stopped using fresh slivered onions and quarter-pound beef patties in several states, both of which are used in Quarter Pounders almost exclusively.
Many cases of E. coli across 10 US states have sickened almost 50 and killed an elderly person in Colorado, stemming from infections linked to McDonald’s Quarter Pounder burgers.
Ten individuals have been hospitalized so far in the outbreak, in which 49 people have been infected, according to a Food Safety Alert from Centers for Disease Control and Prevention.
Those infected have all reported specifically eating a Quarter Pounder at the restaurant chain before falling ill, the federal health agency reports.
The agency urges those feeling sick with symptoms like diarrhea and a fever higher than 102 degrees, severe vomiting, dehydration and dizziness to get in touch with their health care provider.
Most of those infected with the bacteria experience severe symptoms that begin within 3-4 days of consumption, and the majority recover after 5-7 days even without treatment.
However, others may be susceptible to a serious kidney condition called hemolytic uremic syndrome (HUS) and would likely require hospitalization.
As of 2023, there were around 13,450 McDonald’s restaurants in the US, with a location in all 50 states and all but one state capital — Montpelier, Vt.