McDonald’s Quarter Pounder hamburgers are to blame for sickening at least 104 people – and hospitalizing at least 34 – after an outbreak of E coli was tied to onions served on the burgers, federal health officials said on Wednesday.
Cases have been detected in 14 states, according to an update from the US Centers for Disease Control and Prevention. One person died in Colorado and four people have developed a potentially life-threatening kidney disease complication.
At least 30 cases were reported in Colorado, followed by 19 in Montana, 13 in Nebraska, 10 in New Mexico, eight in Missouri and Utah, six in Wyoming, three in Kansas, two in Michigan and one each in Iowa, North Carolina, Oregon, Washington and Wisconsin.
Illnesses were reported between 12 September and 21 October. At least seven people who got sick said they ate McDonald’s food while traveling.
Slivered onions served on the Quarter Pounders were the likely source of the outbreak, the CDC said. Taylor Farms, a California-based produce grower, recalled onions potentially linked to the outbreak. Tests by the US Food and Drug Administration detected a type of E coli bacteria that produces a dangerous toxin in one sample of the onions, but it did not match the strain that made people sick, officials reported.
McDonald’s said on 25 October that onions from Taylor Farms’ Colorado facility were distributed to about 900 of its restaurants in Colorado, Kansas, Wyoming and portions of other states in the region.
The company said it had also decided to stop sourcing onions from the facility indefinitely.
McDonald’s removed the quarter pounder hamburgers from its menu during the early days of the outbreak at locations in Colorado, Kansas, Utah and Wyoming and in parts of Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, New Mexico and Oklahoma. These account for a fifth of its 14,000 US restaurants.
The onions served at the McDonald’s locations are past their shelf life and no longer for sale. CDC officials said the risk to the public remained low.
The type of bacteria implicated in this outbreak causes about 74,000 infections in the US annually, leading to more than 2,000 hospitalizations and 61 deaths each year, according to the CDC.
Symptoms occur quickly, within a day or two of eating contaminated food, and typically include fever, vomiting, diarrhea or bloody diarrhea, and signs of dehydration – little or no urination, increased thirst and dizziness. The infection can cause a type of serious kidney injury, especially in children younger than five. E coli poisoning in young children requires immediate medical attention.
Past outbreaks of the bacterial disease have hampered sales at big fast food restaurants, as customers shun the affected chains.
As news of the McDonald’s outbreak spread, Yum! Brands made the decision to remove fresh onions from menus at some of its KFC, Pizza Hut and Taco Bell chains “out of an abundance of caution”.
Restaurant Brands International, the parent company of Burger King, the McDonald’s rival, removed onions from its menu at at least one outlet in Colorado, the state at the center of the McDonald’s outbreak.
“We’ve been told by corporate to not use any onions going forward for the foreseeable future,” said Maria Gonzales, the on-duty manager inside a Burger King in Longmont, Colorado, on 23 October. “They’re off our menu.”
Associated Press contributed reporting