US cases tied to Europe’s E. coli outbreak

The rarer strains of E. coli found in the United States have generally caused less severe illness, leading to fewer hospitalizations and deaths than the predominant strain, which is known as E. coli O157:H7. That strain has long been the focus of campaigns to eradicate it from the food supply.

The new tally is likely to add to the fierce debate over whether the government should force meatpackers to test for the rarer forms of E. coli and make it illegal to sell ground beef that contains them.

The Agriculture Department, which regulates the meat industry, has drafted new rules that would cover additional forms of E. coli, often called non-O157s, but the rules have become stalled in a review by the Obama administration. The rules have not been made public, but many in the food industry expect them to either ban the sale of ground beef containing the pathogens or to require testing for them.

“Pathogens evolve,’’ Dr. Elisabeth Hagen, the Agriculture Department’s head of food safety, said in a conference call with reporters to discuss the new CDC data. “I don’t think we can afford to stand still while the pathogens are evolving around us.’’

The E. coli outbreak centered in Germany also involves a non-O157 form of the bacteria, but one that is highly virulent. More than 2,400 people have fallen ill.