(Reuters) - The U.S. Centers for Disease Control and Prevention said on Tuesday that the E. coli outbreak linked to McDonald's Quarter Pounder hamburgers is over and the investigation has been closed.

As of Dec. 3, the CDC said 104 people have fallen ill and 34 were hospitalized due to the outbreak caused by the E. coli O157:H7 strain that can cause "very serious disease."

The outbreak was first reported on Oct. 22, with one person reported dead due to the infection resulting from the slivered onions served on the burgers.

Onions were supplied by Taylor Farms, which serves three distribution centers and has already recalled several batches of yellow onions produced in a Colorado facility.

The infection was reported in 14 states: Colorado, Kansas, Utah, Wyoming, Iowa, Missouri, Montana, Nebraska, New Mexico, Oregon, Wisconsin, Washington, North Carolina and Michigan.

The burger chain has resumed selling Quarter Pounders burgers after temporarily taking the item off the menu in a fifth of its 14,000 U.S. restaurants that were impacted.

It has also reintroduced slivered onion from a different supplier into their full menu.