E. coli symptoms to know after McDonald's linked to outbreak

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

The outbreak has killed one person in Colorado, according to the U.S. Centers for Disease Control and Prevention. It has also affected nearly 50 other people in 10 states.

The illnesses may be linked to slivered onions used on Quarter Pounders or the patty itself, but the investigation into the specific contaminated food ingredient is ongoing, the CDC shared in a post Tuesday.