An E. coli outbreak linked to McDonald’s signature Quarter Pounder hamburgers has sickened at least 75 people across 13 states, the Centers for Disease Control and Prevention reported on Friday. One person has died.

The number of illnesses is up from the 49 previously reported and the number of states has increased by three.

At least 22 people have been hospitalized — including two people who have since developed serious complications that can lead to kidney failure — potentially after consuming fresh onions on the hamburgers sourced from the California-based Taylor Farms. The CDC previously reported that 10 people had been hospitalized.

Consumers are thought to have gotten sick between Sept. 27 and Oct. 10.

Major food service distributor US Foods announced on Thursday that Taylor Farms had issued a recall for onions over possible E. coli contamination. A US Foods spokesperson said that the wholesale company is not a supplier to McDonald’s.

The true number of people who have fallen ill is likely much higher and could extend beyond the states currently known to be affected, the CDC said, because not everyone who gets sick will require medical attention and it will take additional time for cases to be linked to the outbreak if more are reported.

McDonald’s said earlier this week it was temporarily removing the Quarter Pounder from the menu in affected areas.

“We are working in close partnership with our suppliers to replenish supply for the Quarter Pounder in the coming weeks,” North America Chief Supply Chain Officer Cesar Piña said in a Tuesday statement. “In the meantime, all other menu items, including other beef products (including the Cheeseburger, Hamburger, Big Mac, McDouble and the Double Cheeseburger) are unaffected and available.”

Shares for the fast food giant were down 2.7% Friday afternoon.