Four people in Western Pennsylvania may have become infected with E. coli after eating at Taco Bell restaurants, an Allegheny County health official said yesterday.

Health Director Dr. Bruce Dixon said the four went to emergency rooms recently with diarrhea and fever. None required hospitalization.

One person was from Aliquippa, and another ate at a Taco Bell in Breezewood, Bedford County, Dr. Dixon said. He did not have information on the other two cases.

Lab tests to confirm the infection are pending, Dr. Dixon said. The four are believed to have become infected with E. coli 0157.

According to the U.S. Centers for Disease Control and Prevention, there have been 62 cases in six states, predominantly in New Jersey and New York, as of Friday.

"The vast majority of patients reported eating at a particular fast-food restaurant chain, Taco Bell," the CDC said. But, "no specific food has been implicated yet."

Bacterial strains from different patients have been "fingerprinted" in terms of their DNA, and the matching results suggest they came from the same source, the CDC said.

Food samples from Taco Bell have been tested, and preliminary findings suggest the presence E. coli 0157 in green onions. The fingerprints of the patient strains and the green onion strains are being compared.

Taco Bell announced Wednesday that it had pulled green onions from its 5,800 restaurants.

Symptoms of E. coli 0157 infection include diarrhea, often bloody, and cramps. They typically begin within three to four days of eating contaminated food, but can occur from one day later to 10 days later, the CDC said.

Some people may develop a complication called hemolytic uremic syndrome, in which red blood cells are damaged and the kidneys fail.

Among those sickened in the current outbreak, about three-quarters were hospitalized, and seven people, or 11 percent, developed hemolytic uremic syndrome, the CDC said.