GENEVA, Feb. 10 (Xinhuanet) -- The confirmation of H5N1 avian influenza in poultry in Africa is a cause for great concern and demands immediate action, the World Health Organization (WHO) warned here on Friday.

    The warning came after Nigerian and international authorities announced on Wednesday that the deadly strain of bird flu virus H5N1 had been detected on a poultry farm in northern Nigeria.

    No human infections have been reported yet in Nigeria, but some 40, 000 birds have died.

    "This is the first reported incidence of this highly pathogenic virus on the continent, where people are already enduring the HIV/AIDS pandemic and other serious infectious diseases," said WHO Director-General LEE Jong-wook in a statement.

    "The H5N1 virus now confirmed in Nigeria poses a risk to human health and livelihood," he said.

    The single most important public health priority at this stage is to warn the Nigerian people about the dangers of close contact with sick or dead birds infected with H5N1, said the statement.

    Experience in Asian countries and most recently in Turkey underscores the fact that immediate and clear public information is critical to the protection of human health, the WHO head said.

    The WHO is offering support to Nigeria's national public information campaign which may include delivering messages to communities during the nationwide house-to-house polio immunization campaign beginning on Saturday.

    The polio eradication infrastructure in Nigeria is also being mobilized to support other essential surveillance and protective measures, such as monitoring for human cases, support for early warning systems, and logistic support for containment, treatment, and laboratory functions.

    "This latest outbreak confirms that no country is immune to H5N1. There is a risk that outbreaks of H5N1 infection in birds could spread within Nigeria and into neighbouring countries, the WHO head said.

    "There is no time to waste. We are ready to help all African countries take measures to reduce the risks of H5N1," he added.

    The confirmation of H5N1 in domestic birds in northern Nigeria marks the further geographical spread of this virus.

    At present, the only confirmed H5N1 outbreak is thought to be confined to a large commercial farm, located in Kaduna State in the northern part of the country, where thousands of chickens were kept in battery cages.

    Poultry deaths in the adjacent province of Kano have been reported, but the cause has not yet been determined.

    In Nigeria, as in other parts of Africa, most village households maintain free-ranging flocks of poultry as a source of income and food. Close human contact with poultry is extensive.

    No clear information about the source of the Nigerian outbreak is presently available, but the country is known to lie along a flight route for birds migrating from central Asia.

    A WHO expert team is expected to arrive in Nigeria on weekend to assess the situation there. Enditem