Officials have confirmed that more than 100 people were infected by a severe E. Coli outbreak linked to slivered onions on McDonald’s Quarter Pounders, Forbes reported. The infections sent 34 people to the hospital and left four with a potentially life-threatening kidney condition called hemolytic uremic syndrome.

Illnesses linked to slivered onions on McDonald's Quarter Pounder burgers expand to 14 states, federal officials say.

The source of the outbreak was likely slivered onions on McDonald's Quarter Pounder burgers, health officials have said.