An E. coli outbreak linked to McDonald’s Quarter Pounders has led to at least 49 illnesses across 10 states, including one death. Here’s what we know. Quarter Pounders made people sick The US Centers for Disease Control and Prevention issued a food safety alert Tuesday warning that dozens of people reported eating the Quarter Pounder sandwich at McDonald’s before becoming sick.

In 10 states throughout the country, 49 people have gotten ill and one has died after an E. coli outbreak at McDonald’s. Infected people reported eating a McDonald’s Quarter Pounder, and experts suspect the beef or the onions on the hamburger sickened folks.

A widespread E. coli outbreak has been linked to a McDonald’s product, according to the CDC. Here's what to know about symptoms, treatment and prevention.