Beijing (AsiaNews/Agencies) – Greater vigilance and more transparency to monitor the unpredictable evolution of bird flu… this is what Shigeru Omi, director of the Pacific section of the World Health Organisation (WHO) said: "With bird flu, anything could happen."

The H5N1 virus has now contaminated all Asia: according to WHO sources, it is unstable and could evolve to the point of reaching a high pathogenic rate [capable of affecting genes of different NDR types]. WHO said that – compared to Vietnam – the virus has appeared at its most pathogenic in China: its spread in Qinghai and in Xinjiang [central-northern regions of the country] has killed several species of flying creatures which had seemed immune to infection at first. The virus therefore made a shift of species, and after recent cases of infection, WHO fears it could pass to a phase of direct human contagion. In Vietnam, the H5N1 appears even more unstable: although the mortality rate dropped from 70% in 2004 to 20% in 2005, there have been cases of people infected with the virus who have not shown any symptoms.

"Information must be circulated in real time and with total transparency," said Omi. He called on the Chinese government to allow WHO to carry out analysis of virus samples and on all Asian countries to develop vaccines and to create antiviral medicines "in expectation of a possible pandemic". Hend Bekedam – director of WHO's China section - said Beijing had not yet given the go-ahead for an inspection of its territory.

At the end of last month, more than 1,000 wild lake birds of the natural reserve of Qinghai were exterminated by the H5N1 virus. The government confirmed an outbreak of the virus also in Xinjiang, where 17,910 geese died. Official sources insist that both were isolated cases and that "all is under control" but the authorities have ordered the closure of all poultry markets in Tacheng.