H5N1 remains an avian influenza and has not taken root in another species, such as pigs.
At each stage, they took tissue samples from the ferrets to see how H5N1 was evolving.
WSJ: Scientists Craft Bird Flu Type That Can Be Transmitted Through Air
H5N1 was first identified in 1997 when there was a huge outbreak in Hong Kong.
H5N1 typically spreads between birds, but can jump to humans, especially if they're living in close proximity.
Experiments in Germany tested 22 flavonoids on human lung cells infected with the H5N1 influenza A virus.
Conservationists also argue that live animal markets have played an important role in the spread of H5N1.
Tests were positive for H5N1, the department said in a statement posted to the Health Ministry's Web site.
Longini would start to seriously worry if the H5N1 mutated to gain an R of 1.7 or higher.
No other cases of the H5N1 avian influenza have been reported from the same area, Xinhua reported.
H5N1 has led to 248 deaths worldwide since 2003, including 21 in China, according to the WHO.
The WHO has said that the current outbreak of H5N1 in birds started in South Korea in December.
Jude Hospital in Memphis, Tennessee, used reverse genetics to produce a vaccine against the H5N1 avian flu virus.
Two groups of scientists independently conducted studies published last year that involved genetically altering a strain of H5N1 influenza.
If H5N1 ever acquired this kind of transmissibility, he says, it probably could not be stopped without a vaccine.
The H5N1 strain of the virus was found in China back in 2003.
So far, every person who died from H5N1 was infected from birds directly.
FORBES: Why One Great Vaccine Researcher Wasn't Afraid Of Bird Flu
In 1997, authorities in Hong Kong killed about 1.5 million chickens after H5N1 avian influenza passed from birds to humans there.
The World Health Organization this week said the subtype isn't thought to be transmitted between humans, unlike the more-common H5N1 strain.
The history of the deadly H5N1 strain has been traced back to infected geese in Guangdong province in China, in 1996.
ECONOMIST: Turkey takes fright as bird flu heads towards Europe | The
The bird flu, H5N1, has the kill rate of over 60% in which 300 out of 500 infections resulted in death.
FORBES: Why One Great Vaccine Researcher Wasn't Afraid Of Bird Flu
It would take between five and nine mutations for the H5N1 flu to become airborne, scientists said, which is a low range.
Last year, it culled hundreds of exotic birds at a market beloved by bird fanciers after a strain of H5N1 was detected.
The only other country with a confirmed H5N1 case this year was Egypt, where a 36-year-old woman died in late January.
Four of the genetic substitutions were in hemagglutinin, a protein on the surface of H5N1 that helps it to enter host cells.
WSJ: Scientists Craft Bird Flu Type That Can Be Transmitted Through Air
The H5N1 virus can move from birds to people through close contact.
WSJ: Scientists Craft Bird Flu Type That Can Be Transmitted Through Air
But they say if the H5N1 strain mutates so it can be passed between humans, it could become a global pandemic, killing millions.
Experts fear that as the number of humans infected with the H5N1 strain increases, the opportunity for the virus to mutate also grows.
ECONOMIST: Turkey takes fright as bird flu heads towards Europe | The
Further, there are rumours that many of these chicks are still arriving from countries with domestic H5N1 infections, such as China and Turkey.
There had been no recorded cases of bird flu infecting people until an outbreak of H5N1 among poultry in Hong Kong in 1997.
The H5 in H5N1 stands for hemagglutinin type 5, meaning the fifth known type of hemagglutinin found on the coatings of influenza viruses.
FORBES: Why One Great Vaccine Researcher Wasn't Afraid Of Bird Flu
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