Recent cases of bird flu outbreak indicate the H5N1 avian
influenza virus may have dangerous mutations, a US bird flu expert
said on Tuesday.
The virus, which has killed several domestic cats in Germany and
Austria, may have acquired the ability of directly transferring
from wild birds to cats and dogs, said Dr. Carol Cardona, a poultry
veterinarian and professor at the University of California,
Davis.
Cardona is part of a network of US researchers providing
education about bird flu. Her laboratory also conducts research on
avian influenza viruses focusing on the disease caused in
chickens.
"Recent cases in Germany and Austria may be a dangerous sign,"
Cardona told Xinhua in a telephone interview.
"We have known that felids could be infected by the virus
easily," she said. "Last year, tigers and leopards in a zoo in
Thailand were killed by the virus after eating fresh chicken, but
the German cases are different."
Generally, the H5N1 virus transfers from wild birds to poultry,
and then goes from poultry to wild birds or other species,
including human, according to Cardona.
But in recent cases, domestic cats were infected after eating
dead wild birds or contacting with them.
"That means, the virus may have acquired the ability of directly
transferring from wild birds to other species, such as domestic
cats or urban dogs," she said. "It may be able to do this without
the poultry."
If the virus can infect domestic cats and urban dogs, which
closely contact with people in everyday life, it will pose more
threat to humans, she said.
There is no evidence that the virus has accomplished the
so-called "species jumping," which means it can circulate among
animals other than the birds.
"But there is the possibility, so we can never underestimate the
virus," she said.
Asian poultry industry must reform
The highly pathogenic H5N1 bird flu has spread from Southeast
Asia to Europe, the Middle East and Africa. So far, the virus
hasn't reached North or South America, but experts say its arrival
is only a matter of time.
The deadly virus has killed millions of birds and more than 100
humans since it appeared 10 years ago.
It mutates, and the big fear among the world's scientists is
that the bird flu virus will join the human flu virus, change its
genetic code and emerge as a new and deadly flu that can even
spread through the air from human to human.
If the virus has mutated into a human flu virus, it does not
necessarily mean it will be as deadly to people as it is to birds,
but experts say they must prepare for the worst.
According to Cardona, the world's poultry industry has suffered
huge losses because of the bird flu outbreak.
"The common consumers, not knowing properly cooked chicken is
safe, refuse to buy poultry products. It happens in Italy and some
other European countries," she said.
And the poultry industry must reform itself to cope with the
bird flu challenge, especially in Asian countries. Breeding poultry
in closed henneries should be safer than outdoor feeding, Cardona
said.
?
"I know that both forms exist in China and other Asian countries,
indoor breeding and outdoor free-ranching," she said.
"Since the bird flu broke out about 10 years ago, no indoor
hennery has been infected, while there are too many cases of
infection in outdoor feeding."
"If they (outdoor poultry farms) are infected, the death rate
must be 100 percent. That means a tragedy for chicken, also means
huge loss and danger to humans."
(Xinhua News Agency March 15, 2006)
