Health experts warn of influenza pandemic threat

Health experts warned today the world was closer to its next pandemic in the form of a potent mix of bird flu and a human influenza virus, with Asia as its likely epicentre.

"We are getting closer, but when it's going to happen, I don't know," said Mr Francois Xavier-Meslin, the World Health Organization's (WHO) co-ordinator for disease control, prevention and eradication.

"If it happens, which is not yet proven, it's going to be worse than Sars. . .  A full-blown flu virus you can transmit easily to people in your family or people you work with. It's a very highly contagious disease compared to Sars."

Sars, or severe acute respiratory syndrome, killed 774 people and infected nearly 8,000, mostly in Asia, in 2003. It caused widespread economic losses throughout the region.

The H5N1 bird flu virus, which devastated the region's poultry stocks, also spread to people, killing 32 in Thailand and Vietnam.

But there was no evidence it had acquired the human-flu traits it would need to be passed easily between people. Once that happens, the result would be a pandemic that could cause as many as seven million deaths, the WHO has warned.

The WHO has in the past raised fears that bird flu could mix with a virus carried by pigs, which are genetically more similar to humans, giving rise to a mutated strain that would become transmissible among people.

However, Mr Xavier-Meslin noted today that widespread, traditional Asian farming methods resulted in close contact between humans and animals, which meant a bird flu virus contagious among people was more likely to come from someone who caught avian influenza directly from poultry.

"For example, in China you have poultry and swine together," he said. "The mix of these could be the likely cause, but the mixing vessel is now thought to be humans."

Mr Hans Wagner of the Food and Agriculture Organisation noted that deadly flu strains in the past had originated from Asia.

"Asia is an area with very high poultry density, human density. Asia has always been a centre of flu, so all these factors come together," he said.

AP