MANILA, Aug. 20 (Xinhuanet) -- The World Health Organization (WHO)said Friday it was troubled that bird flu virus had appeared in poultry in Malaysia, a country that has been implementing aggressive measures to prevent importation of the virus.

    "H5N1 has once more shown how well it is entrenched in parts ofSouth-East Asia," said Dr Shigeru Omi, WHO's regional director forthe Western Pacific, in a statement.

    "It is going to be a long and difficult struggle to eliminate this virus from the environment. And the longer it takes, the greater the risk to public health," Omi said.

    Malaysian authorities Thursday officially informed WHO that H5N1 had been identified in a small flock of free-range chickens in a village in the northern state of Kelantan state, close to theborder with Thailand, where there have been known outbreaks. Thereis no evidence that the virus was imported from Thailand.

    The outbreak in Malaysia was the country's first and no human cases have been confirmed. But Omi repeated earlier WHO warnings that each new outbreak raises the possibility of this happening.

    "As long as the virus circulates in poultry this way, there will be a risk of it jumping to humans, with the potential for a pandemic influenza strain," he said.

    Omi expressed support for Malaysia's veterinary and public-health response to the outbreak and for the prompt manner in whichit informed international organizations, as well as neighboring countries, about the presence of the virus.

    "Transparency such as Malaysia has displayed is vital in the fight against the virus," he said. He also endorsed Singapore's decision to halt the import of poultry and poultry products from Malaysia. "This is in keeping with international recommendations,"he said.

    The Malaysian authorities have introduced a number of measures in response to the outbreak. These include culling all chickens within a one-km radius of the affected village, clinical surveillance of poultry within 10 km and a ban on the movement of poultry within 10 km.

    Members of the public in the affected area have been advised toseek prompt medical assistance if they show symptoms of influenza,surveillance is being tightened in Kelantan and other states, and hospitals, laboratories and clinics have been placed on alert.

    WHO will be working closely on the outbreak with the Malaysian authorities, the Food and Agriculture Organization and the World Organization for Animal Health, the statement said.

    A strain of bird flu claimed 27 deaths in Asia this year. The latest deaths from the H5N1 strain of avian influenza were of three people in Vietnam earlier this month. Enditem