The new mutant strain of bird flu predominant in the mainland, Vietnam and Europe - and which also infected a local woman last year - was introduced by wild birds, an expert said.University of Hong Kong microbiologist Malik Peiris said this is the second time that wild birds introduced the dreaded H5N1, which has wiped out poultry in several countries since re- emerging in 2003, and killed 58 percent of humans infected.
The new strain of H5N1 was found in the territory in 2008, Peiris said.
"We reported that this virus is probably spread by wild birds, and sure enough [it was]. Unfortunately it is now causing outbreaks in Japan, in Vietnam and all the way up to Europe."
This is the second time bird flu has been introduced by wild birds to domestic poultry. "But once it gets into the poultry the maintenance of the virus is by the poultry trade," Peiris said.
The first time was during the Qinghai Lake outbreak of 2005 that killed thousands of wild birds.
"Within a few months the virus spread to many parts of the world including Nigeria, Egypt and several European countries, then ended up in India and Bangladesh," Peiris said. The UN Food and Agriculture Organization last month warned about the new mutant strain that can "sidestep the defenses" of veterinary vaccines.
Reacting to Peiris' remarks, Hong Kong Bird Watching Society director Mike Kilburn said it is reasonable to monitor wild birds.
But he said the myth that migratory birds give people bird flu is being perpetuated by closing Mai Po Nature Reserve each time a live or dead infected bird is found in the vicinity.
The reserve was shut six times in the past six years because of this government policy, the latest being early last year.
However, the guideline was relaxed last November after a campaign by bird- watchers and the World Wide Fund for Nature, which runs Mai Po.
The new rules state the reserve will be closed for 21 days "when no less than three live or dead infected birds are found within a period of 10 days in the three kilometer circular radius of the reserve."
"That's okay because one bird reported infected is no big deal, but closing Mai Po is always news," Kilburn said. "That's what influences public opinion that wild birds are scary."
He said none of the 30,000 wild birds that visit Mai Po each year has yet been found to carry the H5N1 virus, despite extensive monitoring.
