Outbreak blamed on ‘super’ E.coli

“This is a unique strain that has never been isolated from patients before,’’ said Hilde Kruse, a food safety specialist at the World Health Organization. The new strain has “various characteristics that make it more virulent and toxin-producing’’ than the many E. coli strains people naturally carry in their intestines.

However, Dr. Robert Tauxe, a foodborne-disease specialist at the US Centers for Disease Control and Prevention, questioned whether the strain is truly new, saying it had previously caused a single case in Korea in the 1990s. He said the genetic fingerprints from the two samples may vary a little, but not enough to say that the strain in Europe is new.

“Though it appears to have been around awhile, it hasn’t called attention to itself as a major public health problem before,’’ Tauxe said.

Elsewhere in Europe, Russia extended a ban on vegetables from Spain and Germany to the entire European Union to try to stop the outbreak spreading east, a move the EU quickly called disproportionate and Italy’s farmers denounced as “absurd.’’ No deaths or infections have been reported in Russia.

In Hamburg, Philipp, a 29-year old photojournalist, was hospitalized on Monday after falling ill. He would not provide his last name because he did not want people to know he had caught the E. coli strain.

Kruse said it is not uncommon for bacteria to evolve and swap genes. It is difficult to explain where the new strain came from, she said, but bacteria from humans and animals easily trade genes.

Previous E. coli outbreaks have mainly hit children and the elderly, but this one is disproportionately affecting adults, especially women.