An investigation of E. coli linked to onions in McDonald’s Quarter Pounders is being banned in the US

The US government said on Tuesday it had closed its investigation into the outbreak of E. coli that has been tied to McDonald’s Quarter Pounder burgers after it was found to be no longer a safety risk.

The outbreak, which began in late October, has sickened at least 104 people in 14 states, including 34 hospitalized, according to the US Food and Drug Administration. One person in Colorado has died and four people have developed life-threatening kidney disease.

The FDA, which conducted an investigation with the US Centers for Disease Control and Prevention and state health departments, linked yellow onions distributed by Taylor Farms in California and used raw in Quarter Pounders at McDonald’s restaurants in Colorado, Kansas, Wyoming. and other states. Taylor Farms began voluntarily recalling yellow onions on Oct. 22.

State and federal health officials in Colorado have not found a strain of E. coli that caused disease in the onions it tested or in any environmental samples. But they concluded that the evidence points to recalled yellow onions as the likely source of the outbreak.

“McDonald’s is no longer serving the recalled onions and there do not appear to be ongoing food safety concerns related to this outbreak,” the FDA said Tuesday in a statement.

McDonald’s briefly pulled Quarter Pounders from one-fifth of its U.S. stores because of the outbreak. The company found another supplier and resumed selling Quarter Pounders and loose onions in all U.S. stores last month.

A spokesperson for McDonald’s Canada said the concern of E. coli does not spread to Canadian territories.