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

Of those who have fallen ill, 34 were hospitalized; four people developed HUS, a condition that causes kidney failure; and one person died.

McDonald's is investing $100 million to bring customers back to stores after an outbreak of E. coli food poisoning tied to onions on the fast-food giant's Quarter Pounder hamburgers.

McDonald’s is investing $100 million to bring customers back to stores after an outbreak of E. coli food poisoning tied to onions on the fast-food giant’s Quarter Pounder hamburgers. The investments include $65 million that will go directly to the hardest-hit franchises, the company said.

A memo seen by CNN said $35 million is being spent on marketing, with another $65 million going to McDonald's franchisees worst hit by the outbreak.

McDonald's is spending $100 million to bring back customers after an E. coli outbreak infected onion supplies in certain states. So far, 104 cases have been reported, the FDA says.