The avian flu epidemic now sweeping through Asia has already taken a huge toll. Millions of chickens, ducks and other poultry have been slaughtered. Vital exports to the West have been halted. Thousands of peasants in the countries where the disease has spread with astonishing rapidity have seen their livelihoods ruined. And those accused of playing down or trying to conceal the extent of the disaster are now fighting for their political lives.

The human death toll has so far been small: ten people have died in Thailand and Vietnam, although the number of cases in all the countries affected is unclear. But the figures offer no real comfort. The great fear is that the H5N1 virus, which until now has been caught only from birds, may mutate or combine with another influenza strain and spread rapidly from person to person. Ominously, the first such cases of human infection may have already been recorded in Vietnam. Unless this virus can be contained, sober scientists fear a possible pandemic.

As with Sars, the focus of concern is China. Both the human and poultry population are the world’s largest. And conditions for the rapid spread of the disease are almost ideal: most farmers and peasants live in close proximity to their birds and animals, hygiene in the vast commercial chicken farms is often poor, the tradition of selling live birds makes every market a catalyst for infection, and migrating birds are able to spread the virus rapidly over the huge landmass. Equally worrying is the political failure to respond effectively and transparently. The tradition of cover-up, even after the Sars disaster, lingers on. China has still not replied to the request two weeks ago by the World Health Organisation for more information on avian flu. And a WHO spokesman gave a grim warning at the weekend that, although China had a small window of opportunity to contain avian flu, “that window grows smaller with each passing day”.

Party officials in China insist that they are dealing with outbreaks. Teams are killing all poultry within a two-mile radius of each outbreak. Millions of birds have been slaughtered and burnt in holes in the ground, officials said, by teams wearing the same protective suits as those who dealt with Sars. In addition, the Ministry of Agriculture claims that it has now developed a human vaccine that is “100 per cent effective”.

Such measures are to be welcomed. But China’s past record does not inspire confidence. There are still worries about the public health aspects of the culls. Reporting of the disease is still patchy. And China has only one national bird flu laboratory authorised to examine samples of the H5N1 virus.

China should have learnt from Sars the dangers of complacency. That disease, as expected, has returned, with confirmation of four new cases. Both Chinese and WHO experts have given warning that the country still lacks experts on dealing with emerging diseases. So too do most countries struggling to contain avian flu. What they can do, however, is take the precautions essential to prevent the disease spreading: close markets, halt exports, report infections and give WHO all the information needed to mount a global campaign. Disgracefully, Thailand hushed up its outbreak for two months to protect its $1.2 billion chicken export industry.

WHO, whose prompt action was largely responsible for halting the spread of Sars last year, is caught between the competing fears of complacency and alarmism. But as Sars showed, however costly the economic consequences, it is better to err on the side of alarmism.

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