The new cases reported on Friday were a sharp increase from the initial count of 49 in 10 states. The most illnesses were reported in Colorado, with 26 cases. At least 13 people have become ill in Montana, 11 in Nebraska, five each in New Mexico and Utah, four each in Missouri and Wyoming, two in Michigan and one each in Iowa, Kansas, Oregon, Wisconsin and Washington, the CDC reported .

McDonald’s said Friday that it has not pulled the Quarter Pounder from other restaurants because of the CDC’s increased number of illnesses. The company noted that some cases in states outside the original region were travel-related.

The CDC said some people who got sick reported traveling to other states before symptoms started. At least three people said they ate at McDonald’s during their trip. The illnesses were reported between September 27 and October 11.

Taylor Farms notified its customers directly about the onion recall but did not tell the public about it, an FDA official said. Companies often issue press releases, and the FDA sends out public notices for recalls, but these are not mandatory.

While it remains unclear whether the recalled onions were the source of the outbreak, several other fast-food restaurants — including Taco Bell, Pizza Hut, KFC and Burger King — pulled onions from some menus in certain areas this week.

Restaurant Brands International, which owns Burger King, said 5 percent of its restaurants use whole onions distributed by its Taylor Farms unit in Colorado. They are washed, peeled and sliced ​​by the employees.

Even though it was not contacted by health officials and had no signs of illness, Restaurant Brands said it has asked restaurants that received onions from the Colorado facility to get rid of them.

The outbreak involves infections with E. coli 0157:H7, a type of bacteria which produces a dangerous toxin. It causes about 74,000 infections in the U.S. annually, leading to more than 2,000 hospitalizations and 61 deaths each year, according to the CDC.

People sickened by the outbreak have already moved to sue McDonald’s, according to court filings. According to her lawsuit, Clarissa DeBock ate food at a local McDonald’s in Nebraska on September 18, became ill on September 23 and sought emergency care two days later before being diagnosed with an E. coli infection.

Symptoms of E. coli poisoning can appear quickly, within a day or two of eating the contaminated food. These usually include fever, vomiting, diarrhea or bloody diarrhea and signs of dehydration – little or no peeing, increased thirst and dizziness. The infection is especially dangerous for children under 5 years old, the elderly, pregnant people or those with a weakened immune system.

AP business reporter Dee-Ann Durbin contributed reporting from Detroit.