BEIJING (AP) _ A Chinese laboratory said Friday that a deadly strain of bird flu has been found in pigs, expanding the number of species that can be infected with the disease.
Bird flu ravaged poultry flocks throughout Asia earlier this year and killed 27 people in Vietnam and Thailand.
Researchers at the Harbin Institute of Veterinary Medicine have found the deadly strain, known as H5N1, in pigs, a lab worker said by phone from the northern Chinese city of Harbin. He would give only his surname, Yang.
Yang wouldn't give any other details.
The deadly strain of bird flu has so far been found to be capable of spreading from poultry to people, not directly from one person to another. But health experts worry that it could mutate into a form that can be transmitted among humans.
``The fear always is that this will jump to mammals,'' Chen Hualan, chief bird flu researcher at the Harbin laboratory, said at a conference in Beijing on the disease.
Lab workers have been able to infect mice with the lethal strain of bird flu called H5N1, Chen said. She said researchers earlier found a milder strain of bird flu in pigs.
But ``the mechanisms for the H5N1 virus to cross the species barrier and infect and kill mammals are still unknown,'' she said.
Malaysia this week became the latest country to report bird flu in poultry and has gone on nationwide alert against the disease.
Bird flu ``is not very good at jumping from animals to humans at this point in time, but it can do so,'' said Dr. Julie Hall, a World Health Organization expert in Beijing. ``It is very important that we prepare for that eventuality.''