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.

The first lawsuits related to a deadly outbreak of E. coli in the fast food giant’s hamburgers have been filed in Cook County, Illinois. One suit was filed on Thursday on behalf of Colorado resident Eric Stelly, who was one of dozens of customers across the country who have been exposed to the bacteria.