Aisa: Two more people died in Vietnam of bird flu, taking Asia's death toll yesterday to 18, but UN agencies dismissed earlier reports that the virus had spread to pigs.
A day after China said bird flu had spread to more provinces and UN agencies chided Asian countries for being slow to sound the alarm, a Food and Agriculture Organisation (FAO) official in Vietnam said three or four pigs had tested positive for the virus.
That was a worrying development since the immune system of pigs is similar to that of humans, but a FAO scientist in Rome said said the tests referred to were not up to standard.
"The news that he reported was based we believe on studies with an experimental test," Peter Roeder, a FAO animal health expert, said.
Robert Webster, a World Health Organisation animal flu expert, added: "Right now there is no justification for saying there is H5N1 virus infection in pigs in Vietnam." Scientists say pigs are ideal vessels for mixing genes from the bird flu pathogen and the human influenza virus.
The WHO has said this could result in the emergence of a new subtype of virus for which humans would have no immunity.
"If there was a very widespread infection in pigs, then that would be a great concern that a pandemic strain might develop from it," Jacqueline Katz, a flu expert at the US Centres for Disease Control and Prevention, said last week.
The world animal health body OIE said it would not be surprised if pigs in Asia tested positive for the H5N1 bird flu virus.
"It would not be a surprise because the potential susceptibility of pigs to avian influenza virus is well known," the Paris-based OIE said.
The OIE said it recommended that countries with avian flu closely monitor pigs which were in contact with infected birds.
Experts say the possibility of a new strain sweeping through a human population with no immunity to it is remote, but that each outbreak narrows the odds a little.
The FAO and WHO have been urging affected countries to act swiftly to stamp out the H5N1 virus, preferably by slaughtering poultry within three km of an outbreak. - (Reuters)