The number of people infected in a multistate outbreak of Shiga toxin-producing Escherichia coli linked to McDonald's Quarter Pounder hamburgers has risen from 49 to 75, the Centers for Disease Control and Prevention (CDC) said today in an update.
The outbreak of E coli O157:H7 has now affected people in 13 states, up from 10, with 22 people now hospitalized and 2 people diagnosed with hemolytic uremic syndrome, a serious condition that can cause kidney failure. One death was previously reported in an older adult in Colorado, which has reported the most cases (26).
The other states affected by the outbreak are Iowa, Kansas, Michigan, Missouri, Montana, Nebraska, New Mexico, Oregon, Utah, Washington, Wisconsin, and Wyoming.
More signs point to slivered onions as the source
Meanwhile, the investigation into the source of the outbreak continues. Of the 42 people who have been interviewed by the CDC so far, all 42 report eating at McDonald's, 39 report eating a hamburger, and 31 say the hamburger was a Quarter Pounder.
While the Food and Drug Administration's Food Safety and Inspection Service (FDA-FSIS) is conducting trace-back investigations on hamburger patties, preliminary data reviewed by the agency are pointing to slivered onions as the source.
In its update on the investigation, the FDA said that Taylor Farms, a California company with a Colorado facility that supplies slivered onions to the affected McDonald's locations, has initiated a voluntary recall of the product. Other customers who received onions from the company have been notified of the recall. The FDA says it's collecting onion samples for analysis and working with federal and state partners and the companies involved to evaluate records and distribution information as part of its investigation.
The Associated Press reports that the outbreak has prompted other national restaurant chains to temporarily stop using fresh onions. Among them is Restaurant Brands, which owns Burger King and said that 5% of its restaurants use onions distributed by Taylor Farms' Colorado facility. Yum Brands, which owns Taco Bell, KFC, and Pizza Hut, is another.
In addition to pausing distribution of all slivered onions supplied by Taylor Farms, McDonald's has also temporarily removed Quarter Pounders from restaurants in the impacted states.
E coli O157:H7 causes severe stomach cramps, bloody diarrhea, and vomiting. Symptoms typically start 3 to 4 days after ingesting the bacteria, and most people recover without needing treatment. The CDC says people should call their healthcare provider if they've recently eaten a Quarter Pounder and are experiencing E coli symptoms.
