At least 75 people fall ill as McDonald’s deadly E. coli outbreak spreads

A deadly outbreak of E. coli poisoning linked to McDonald’s Quarter Pounders has spread, with at least 75 people sickened in 13 states, federal health officials said Friday.

Twenty-two people have been hospitalized, the Centers for Disease Control and Prevention said. Two people developed a dangerous complication of kidney disease and one died.

No source of the outbreak has been identified, U.S. Food and Drug Administration officials said. But researchers have focused on the chopped onions used in hamburgers, as well as beef patties.

McDonald’s officials have said that a California-based produce producer, Taylor Farms, supplied yellow onions that have been recalled for possible E. coli contamination. McDonald’s pulled the burger from menus in several states on Tuesday when the outbreak was announced.

Infections were reported as of Sept. 27 in Colorado, Iowa, Kansas, Missouri, Montana, Nebraska, Oregon, Utah, Wisconsin and Wyoming. Colorado has the most cases.

Everyone interviewed in connection with the outbreak had reported eating at McDonald’s before getting sick, and most mentioned eating Quarter Pounder burgers, the CDC said. The U.S. Department of Agriculture, the Food and Drug Administration and state health officials are also investigating.

The E. coli bacteria lives in the intestines of animals and is found in the environment. Infections can cause serious illness, such as fever, stomach cramps, and bloody diarrhea. People who develop symptoms of E. coli poisoning should seek medical attention immediately and tell their provider what they ate.

The news comes in an already difficult year for the Chicago-based McDonald’s chain. Its overall same-store sales fell for the first time in nearly four years in the second quarter, as inflation-weary customers stopped eating out or chose cheaper options. The company responded with a $5 meal deal, which was introduced in U.S. restaurants in late June and recently extended through December. The deal does not include the Quarter Pounder.

McDonald’s shares fell 9% in after-hours trading Tuesday after the CDC announcement.

The type of bacteria implicated in this outbreak, E. coli O157:H7, causes about 74,000 infections in the U.S. each year, resulting in more than 2,000 hospitalizations and 61 deaths. Infections are especially dangerous for children under 5 years of age and can cause acute kidney failure.