An avian flu sweeping Hong Kong poultry farms is mutating fast and
officials are fighting to stop it from evolving into a strain that
crossed to humans and killed six people in 1997, a top scientist
said on Wednesday.
"At the moment, it does not present an immediate threat (to
humans). But that threat is if it does happen to go to the right
type of reassortment (mutation)," Ken Shortridge, who is studying
the virus, said on Hong Kong RTHK radio.
"It will need one little chance ... and this could give rise to a
serious virus."
Earlier, Shortridge told the daily South China Morning Post that
the bird flu outbreak came from the same family of viruses that
mutated into the deadly human strain in 1997.
That outbreak forced authorities to slaughter all domestic fowl,
more than a million birds. The latest scare hit as Hong Kong
prepares for Chinese New Year next week, when fresh chicken is a
main dish.
Hong Kong health officials have tried to move quickly to stop the
virus before it mutates into a rogue strain that threatens
humans.
Some 169,000 birds from two farms and four markets have been killed
since the weekend and 24 more poultry farms were shut on
Tuesday.
Imports of live chickens, mostly from Chinese mainland are halted
on Wednesday and Thursday and chicken sales will be halted on
Friday so "all poultry stalls and fresh provision shops can be
thoroughly cleansed and disinfected", a government statement
said.
About 20 percent of some 100,000 live chickens sold daily are
raised in the territory. The remainder comes largely from the
mainland.
Shortridge said the danger came from the speed with which the virus
was mutating in Hong Kong's aquatic bird population. It could
become a risk to humans but so far this was not the case.
The government has said the virus had not been identified as yet,
but Shortridge said it was from the H5N1 goose family from which
the 1997 strain that killed humans emerged.
"It is still the Guangdong goose family (of H5N1) but it is moving
away from the Guangdong virus of 1996," the parent strain of the
1997 flu, he said.
"The way the virus is behaving now, we are seeing it undergo many,
many of what we call reassortment, swapping genes with many other
viruses quickly," he told RTHK on radio.
Hong Kong had to order a mass cull of 1.2 million birds last May
after another virus scare.
Agriculture officials in neighbouring Guangdong province and
Shenzhen city in southern China said they had seen no sign of the
bird flu outbreak.
(China Daily February
06, 2002)