The likely source of the E. coli outbreak linked to McDonald’s is onions, according to federal agencies; 15 more cases have been reported

() – Fresh sliced ​​onions served on McDonald’s Quarter Pounder burgers are the likely source of an outbreak of E.coli which has caused one death and illness in more than a dozen states, the Centers for Disease Control and Prevention and the US Food and Drug Administration (CDC and FDA, respectively) reported on Wednesday.

Additional cases associated with the outbreak were also reported, bringing the total number of illnesses to 90 and the number of hospitalizations to 27. However, the CDC notes that the current risk to the public is “very low,” as infections The reported incidents occurred before the affected onions were removed from food venues.

“It is not necessary to avoid the consumption of onions or other foods made with onions,” the CDC noted.

Last week, supplier Taylor Farms issued a recall on four onion products due to “possible E. coli contamination.” McDonald’s stores in affected areas have temporarily stopped using sliced ​​onions, and other fast food restaurants that received onions from this supplier – including Burger King, Taco Bell, Pizza Hut and KFC – have removed fresh onions from their menus in some local.

The recalled onions are not likely to have ended up in grocery stores or directly to consumers, the CDC said Wednesday. The chopped onions used at McDonald’s are also not linked to this outbreak, according to the FDA.

The beef used in the Quarter Pounder burgers was also part of the investigation, which began on October 22. But the Colorado Department of Agriculture said Sunday that McDonald’s fresh beef burgers used for the Quarter Pounder tested negative for E.coliand the U.S. Department of Agriculture’s Food Safety and Inspection Service said Monday that testing did not point to ground beef as a likely source of the outbreak.

McDonald’s announced Sunday that it would resume selling Quarter Pounder in all restaurants this week, but the 900 restaurants that had previously received sliced ​​onions from Taylor Farms would not include onions.