'Hidden' H5N1 is mainland's challenge: WHO Beijing chief

The mainland faces a challenge to identify where the bird flu virus is 'hiding' and to fight it at source, says the World Health Organisation's top man in Beijing.

The H5N1 virus might be hiding in healthy-looking ducks and geese, partly because of a massive vaccination programme that resulted in birds being only partly immunised against the deadly virus, said Henk Bekedam.

'In China we have 22 human cases - 21 were not forewarned by poultry,' said Dr Bekedam, the WHO Representative in China, in a telephone interview. 'I do not think that in more than 10 [cases] we were able to make a link to poultry.'

Seven dead birds in Hong Kong have been found with H5N1 since New Year's Eve, and the first human case in six months was confirmed on the mainland.

Dr Bekedam said the mainland - as well as Thailand and Vietnam - should now review the point they had reached in their bird flu campaigns.

'They have to see what they have been able to achieve and see the remaining challenge: it is very much in trying to identify where the virus is hiding. The virus is still there, otherwise there would not be cases of bird flu in Hong Kong and mainland human cases,' he said.

'It has been shown by the University of Hong Kong research,' he added.

Virologists from the university, including Guan Yi and Malik Peiris, have published groundbreaking research on how the so-called Fujian-like virus has emerged as the dominant sub-strain in southern China and has been detected in Laos, Thailand and Hong Kong.

Dr Bekedam said: 'We know the virus is still there and also in birds which are not even sick. If you fight a war, you have to direct the war to where the viruses live - maybe ducks and geese.' He said while bigger poultry farms had been doing well with their control measures, 'the challenge is still very much in the backyard'.

Dr Bekedam also cautioned against complacency - brought on by 'bird flu fatigue'. He said: '[Bird flu] is a threat, it will never go away and we must be on guard.'

WHO director-general Margaret Chan Fung Fu-chun, Hong Kong's former director of health, arrived in Bangkok yesterday for an official visit as a guest of the Thai government and will speak at the two-day Prince Mahidol Award Conference which opens today.

With retired University of Hong Kong microbiology professor Ken Shortridge, Dr Chan received the award in 1998 for their fight against H5N1 after six out of 18 people died in Hong Kong. It was the first time the virus had infected humans. The award was established in 1992.