Bird Flu Virus Spreads to Pakistan

Pakistan was today added to the list of nations affected by a lethal new strain of bird flu spreading across Asia.

The country said that it had detected a form of the virus in its chickens, with the news coming as a six-year-old Thai boy became the seventh confirmed bird flu fatality.

The child, who died in a Bangkok hospital last night, was Thailand's first confirmed death from the virus. He had been infected while playing with chickens in his home village.

Six people have so far died from bird flu in Vietnam, and Thai officials are also trying to determine whether the virus was responsible for last week's death of a 56-year-old man who bred fighting cocks.

Despite its similarities to the influenza virus in humans, bird flu very rarely jumps species to infect people. It usually only causes infections in birds and pigs.

However, the deadly H5N1 strain of the disease, which can infect humans, has been found in bird populations in Japan, South Korea, Thailand, Cambodia and Indonesia since it first emerged in Vietnam at the end of last year.

Laos fears that it could also be hit, and is awaiting the results of tests on the nature of an illness that is killing its fowl.

The World Health Organisation said that the rapid spread of the virus was "historically unprecedented", and called on the global scientific community to accelerate the search for a cure.

There is no evidence of person-to-person transmission, but health officials fear that the H5N1 strain could mutate to allow such an infection if it merged with a human flu virus.

Attempts to tackle the bird flu are being frustrated by its fast rate of mutation and its rapid spread.

One theory is that the strain is being spread to domestic chicken populations across Asia by migratory wildfowl.

"This is now spreading too quickly for anybody to ignore it," WHO spokesman Peter Cordingley said.

Affected nations have culled chicken flocks in a desperate bid to contain the disease. Vietnam has slaughtered more than three million birds, and Thailand more than nine million.