October 22, 2024 — A fast-moving E. coli outbreak linked to McDonald’s Quarter Pounder hamburgers has sickened at least 49 people across 10 states, according to federal and state health officials.
Preliminary investigation suggests that slivered onions used in these burgers may be the source of contamination.
The outbreak, caused by the dangerous E. coli O157 strain, has led to 10 hospitalizations and one death, reported in Colorado. One patient developed hemolytic uremic syndrome (HUS), a severe complication that can cause kidney failure.
Early Investigation Points to Onions
The Centers for Disease Control and Prevention (CDC), the Food and Drug Administration (FDA), and the U.S. Department of Agriculture (USDA) are actively investigating the outbreak. Traceback data reviewed by the FDA indicates that the onions used in Quarter Pounders are a likely source of the contamination. Officials are also tracing the ground beef patties to rule out additional sources.