McDonald's Quarter Pounder hamburgers have been linked to an outbreak of E. coli, a bacteria that can make people sick. Here's what to know.

So far, 49 illnesses have been reported in 10 states, including 10 people who were hospitalized. One of those hospitalized is a child who developed hemolytic uremic syndrome, a serious complication that can develop from an E. coli infection. An older person has also died in connection with the outbreak.