Seventy-five people across 13 states have fallen ill in an E. coli outbreak attributed to McDonald's Quarter Pounders.

Health officials say that recalls of onions — the suspected source of the contamination — would help lessen the risk to consumers. Other major fast-food chains have also stopped offering onions.

McDonald's has paused Quarter Pounder sales in some states amid an E. coli outbreak, while foods ranging from smoked salmon to frozen waffles are under review.