The number of E. coli cases linked to McDonald’s Quarter Pounders has risen to 90, the Centers for Disease Control and Prevention said Wednesday, up from 75 reported cases Friday.
The slivered onions used on the burgers are the “likely source” of the outbreak, the CDC said.
A spokesperson for McDonald’s said all Quarter Pounders in affected states had been pulled from the restaurants by Oct. 22, when the outbreak was announced.
The CDC said any further risk to the public is “very low.” The most recent case was on Oct. 16.
On Sunday, Colorado Agriculture Department officials ruled out the beef patties used in the Quarter Pounders as the outbreak’s source after testing found no traces of E. coli.
One person has died and 27 have been hospitalized, the CDC said. At least two people developed a rare kidney illness called hemolytic uremic syndrome.
A family in Grand Junction, Colorado, told NBC News that their 15-year-old daughter is one of those who developed the kidney condition.
The high school freshman’s initial symptoms — fever and stomach pain — began just days after she went to her local McDonald’s several times for a Quarter Pounder. She experienced vomiting and diarrhea with blood.
She has since been hospitalized with kidney damage, the family said, and has had to undergo multiple rounds of dialysis.
The true number of cases linked to the Quarter Pounders is likely to be much higher than the 90 reported so far. Most people with E. coli infections are never tested for the bacterium and recover on their own.
Thirteen states have reported cases: Colorado, Iowa, Kansas, Michigan, Missouri, Nebraska, New Mexico, Montana, Oregon, Utah, Washington, Wisconsin and Wyoming.
The Food and Drug Administration has also said the slivered onions, supplied by food producer Taylor Farms Colorado Springs, are the most likely source of contamination.
The FDA said Wednesday that in addition to inspecting a Taylor Farms processing center in Colorado, it’s also looking into an “onion grower of interest” based in Washington state.
According to McDonald’s, 900 restaurants across 12 states received the onions from Taylor Farms.
McDonald’s said it stopped sourcing onions from the company indefinitely on Friday. It’ll start selling the Quarter Pounder without onions in affected stores this week.
Other restaurant chains in Colorado, including Taco Bell, Burger King, KFC, Pizza Hut and Illegal Pete’s, removed onions from their menus out of an abundance of caution. There are no signs that people have gotten E. coli after having eaten at those restaurants.
