E. coli cases linked to McDonald's Quarter Pounders rise to 75 in 13 states: CDC

The number of cases in a deadly E. coli outbreak linked to McDonald's Quarter Pounders has risen to 75, according to new federal data released Friday.

According to the Centers for Disease Control and Prevention (CDC), cases have been reported in 13 states.

Most of the cases have occurred in Colorado, with 26 cases reported, and Montana, with 13 cases reported, according to the CDC.

Cases have also been reported in Iowa, Kansas, Michigan, Missouri, Nebraska, New Mexico, Oregon, Utah, Washington, Wisconsin and Wyoming, according to the CDC, which also indicates illnesses occurred between September 27 and October 10 are this year.

Of the 61 people the CDC has information about, 22 were hospitalized and two developed hemolytic uremic syndrome, a serious, potentially fatal complication of E. coli infection that can lead to kidney failure, according to the CDC.

One death has been reported in Colorado in connection with the outbreak. According to the Mesa County Health Department, the person lived in Mesa County in the western part of the state.

“The actual number of people sickened in this outbreak is likely much higher than the reported number, and the outbreak may not be limited to those states with known illnesses,” the CDC said in its update. “This is because many people recover without medical care and are not tested for E. coli. Additionally, recent illnesses may not yet be reported because it typically takes three to four weeks to determine whether a sick person is part of an outbreak.”

According to McDonald's, either fresh, chopped onions or beef patties used in the Quarter Pounder could be behind the outbreak.

After initially announcing the outbreak on Tuesday, the fast food company said it had proactively removed two ingredients from stores in two affected regions. The company's leadership team said most other menu items were not affected, according to the CDC investigation.

McDonald's confirmed in a statement to ABC News that Taylor Farms is the supplier of the sliced ​​onions that the fast food chain removed. The U.S. Food and Drug Administration (FDA) is investigating but has not definitively identified the source of the E. coli, although it has said the onions were a “likely source of contamination.”

In an updated statement Friday, McDonald's said chopped onions from a Taylor Farms facility in Colorado Springs were distributed to about 900 McDonald's restaurants in Colorado, Kansas, Wyoming and parts of other states. Some were at airports, “which could be responsible for illnesses in other states,” McDonald's said.

“Nothing is more important to us than the quality and safety of our food, which is why McDonald's has taken swift and decisive action to protect the health of our customers,” the fast food company said in its updated statement.

McDonald's said it had removed all onion slivers from the Taylor Farms facility from its restaurants as of Oct. 22, but “due to general concern and our unwavering commitment to food safety, we have decided to no longer remove onions from the Taylor Farms facility in Colorado Springs.” unlimited.”

Taylor Farms issued a voluntary recall of its raw onions on Wednesday.

ABC News' Kelly McCarthy and Taylor Dunn contributed to this report.