Scientists in China say they have discovered a highly virulent strain of bird flu virus in pigs. An official at the China National Avian Flu Reference Laboratory said the H5N1 virus strain had been found in pigs at several farms in the country. The spread to pigs has yet to be confirmed, but there could be serious implications for human health if it is. The World Health Organization said that if the pigs were harbouring both bird and human flu viruses, the two strains could interact to create a strain capable of transferring easily to humans. According to the Chinese scientists the virus had been discovered in pigs in south-east Chinas Fujian province in 2003, and in "another place" in 2004.
Comment The finding has not yet been confirmed, and it is not yet clear whether the pigs were actually infected with the virus (i.e. the virus replicating inside the pigs respiratory tract cells) or merely found without actually infecting the pigs. If the H5N1 infection actually infected the pigs the possibility increases of adaptation of the H5N1 towards a virus with higher capability of infecting humans. More than 20 people died and almost 200 million birds were culled during a flu epidemic in Asia earlier this year.