An elderly person died in Colorado, and a child has been hospitalized with severe kidney complications, the United States Centers for Disease Control and Prevention (CDC) reported.
Infections were reported between September 27 and October 11 in Colorado, Iowa, Kansas, Missouri, Montana, Nebraska, Oregon, Utah, Wisconsin, and Wyoming. Colorado has the highest number of cases with 26, followed by Nebraska with nine.
All individuals interviewed regarding the outbreak had reported eating at McDonald's before getting sick, with most stating they had eaten Quarter Pounder hamburgers, the CDC pointed out. The United States Department of Agriculture (USDA), the Food and Drug Administration (FDA), and state health authorities have also initiated investigations.
A specific ingredient has not yet been identified as the cause, but researchers are focusing on onions and meat. A preliminary investigation suggests that the possible source of contamination was the onions served in the hamburgers. The USDA is analyzing the meat.
McDonald's released a statement indicating that preliminary findings suggest that some of the cases are linked to onions from a single supplier. The company has suspended the distribution of these onions and has temporarily removed Quarter Pounder hamburgers from menus in the affected states, as well as parts of Idaho, Nevada, New Mexico, and Oklahoma.
"We take food safety very seriously, and this is the right thing to do," the company stated.