Oct 25 (Reuters) - The number of people infected by the

E. coli outbreak tied to McDonald's Quarter Pounder

hamburgers increased to 75 from 49, the U.S. Food and Drug

Administration said on Friday.

Of the 61, on whom information was available, the health

regulator said 22 persons have been hospitalized. Two of them

have developed hemolytic uremic syndrome, a serious condition

that can cause kidney failure.

The E. coli O157:H7 strain that has caused the death of one

person is said to cause "very serious disease", especially for

the elderly, children and people who are immunocompromised.

The world's largest burger chain temporarily paused serving

the Quarter Pounder in a fifth of its 14,000 U.S. restaurants

that were impacted, the company had said on Wednesday.

Slivered onions used in the Quarter Pounder was the likely

source of the outbreak and it was supplied by a single supplier

that serves three distribution centers, initial findings of the

FDA as well as the company showed.

Taylor Farms was the supplier for the affected locations and

McDonald's has initiated a voluntary recall, the company and the

agency said. The supplier also recalled several batches of

yellow onions produced in a Colorado facility.

The U.S. Department of Agriculture said late on Wednesday

even though onions are the likely suspects, one of its state

partners is testing samples of the beef used in the burger for

E. coli.

As of Oct.24, the outbreak has affected Colorado, Kansas,

Utah, Wyoming, Iowa, Missouri, Montana, Nebraska, New Mexico,

Oregan, Wisconsin, Washington and Michigan. Colorado reported 26

infections.

Due to the product actions taken by McDonald's and Taylor

Farms, the risk to the public is very low, the Centers for

Disease Control and Prevention said on Friday.

Other major U.S. fast food chains such as Taco Bell owner

Yum and Restaurant Brands unit Burger King were pulling fresh

onions out of their menu items. These restaurant chains also

source from Taylor Farms.

Shares of McDonald's were down 2% in mid-day trading.

"We continue to believe that more infections are possible in

the near term, and the greatest risk to investor, is the

continuous negative news cycle," BTIG analyst Peter Saleh said.

(Reporting by Ananya Mariam Rajesh and Aishwarya Venugopal in

Bengaluru; Editing by Sriraj Kalluvila and Arun Koyyur)