Richard T. Nowitz via Getty The scope of the McDonald’s E. coli outbreak has gotten larger. Health officials have reported a substantial increase in cases this week, with many more cases likely having gone unnoticed. The U.S. Centers for Disease Control ...

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

A deadly E. coli outbreak connected to slivered onions served in McDonald's Quarter Pounder hamburgers across the country has sickened at least 104 people, federal health officials said.

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

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.

The E. coli case total has risen to 104 in the outbreak linked to McDonald’s Quarter Pounders. Slivered onions still appear to be the most likely source of the contamination.