New threat of world flu epidemic

A lethal strain of bird flu could become another global pandemic killing millions, scientists warned today.

Asian bird flu has so far killed 32 of the 44 people who have caught it - mostly as a result of direct contact with infected chickens.

But now scientists have found it has spread from person to person. There are fears that if the virus took hold within humans an epidemic could spread on a scale not seen since 1918, when 40 million people are thought to have died from a strain that mutated from bird flu.

Researchers warned the case of person-to-person transmission should act as a reminder of "the urgent need to prepare for a future influenza pandemic".

A research paper published by the New England Journal of Medicine documents the case of an 11-year-old girl in Thailand who caught strain A avian flu from infected chickens. She died five days later.

Her mother, who had no contact with chickens but who had nursed her daughter, fell ill and died the same month. The girl's aunt also became ill but later recovered.

Tests carried out in Bangkok and at the Centres for Disease Control in Atlanta found all three had contracted avian influenza A. The paper said person-to-person infection had been of "intense concern" but there had been little evidence until now. In an accompanying article Dr Arnold Monto, professor of epidemiology at Universityof Michigan school of public health, said there was no further spread between people other than from the girl.

This showed the virus had not mutated considerably. But he warned that these changes would happen.

Dr John Watson, head of the respiratory diseases department at the Health Protection Agency, said the risk to people in the UK was still low.

However, ministers are drawing up plans to close down London and other big cities in the event of a pandemic.