BEIJING, Jan. 23 (Xinhuanet) -- Bird flu virus mutations that could make it easier for the virus to infect humans have been found in a sample taken from a patient in Turkey, according to a report published in the journal Nature.

    The mutations, which were recently detected by scientists at a London lab, may "signify the virus is trying different things to see if it can more easily infect humans," WHO's spokeswoman Maria Cheng said in Geneva. "So far, we haven't seen that the virus has the ability to do this. But it's important that we continue monitoring."

    One mutation found "suggests the virus might be more inclined to bind to human cells rather than animal cells," Cheng said, but there's no evidence that it's becoming more infectious.

    "If we started to see a lot more samples from Turkey with this mutation and saw the virus changing, we'd be more concerned," she said.

    Flu viruses mutate all the time, Cheng said. "For us to assign public health significance to a genetic change we need to match it to what is happening epidemiologically ¡ª how the virus is behaving ¡ª and clinically ¡ª if it's more or less virulent," Cheng said.     

    The Nature report cites a second mutation that also "signals adaptation to humans."     

    The H5N1 strain first infected humans in 1997. It re-emerged in 2003 and, although it has not been stamped out, health officials have seen no evidence yet that the virus can spread easily in humans.

    "We would be concerned if we were seeing successive generations of spread of the virus" in Turkey, Cheng said. "We haven't so far. All these people had a very clear history of contact with diseased birds." Enditem

    (Agencies)