June 30, 2005

WHO calms fears of bird flu virus mutation

GENEVA (Reuters) - Tests have yielded no evidence so farthat the bird flu virus is mutating and becoming easier totransmit between humans, the World Health Organization said onThursday.

In May the WHO warned that the virus in Vietnam, thecountry with the highest number of cases, could be changing andbecoming easier to pass on.

Such a mutation could herald the start of a long-predictedinternational flu pandemic capable of killing millions ofpeople around the world.

But the Geneva-based body said in a brief statement thatlaboratory and epidemiological examinations of recentVietnamese cases, carried out by an international team, hadrevealed no change to the virus.

"We did not find evidence to substantiate what wassuggested in Manila," said WHO spokeswoman Maria Cheng,referring to the meeting in the Philippines where the concernsfirst surfaced.

"They (the investigators) have not found any change in thevirus," she said, but she added further tests would be needed.

"While these results are reassuring, further testing ofclinical specimens will continue over the next few weeks toprovide the most reliable possible foundation for riskassessment," the WHO statement said.

Cheng said that the tests would be carried out inlaboratories in the United States, Britain and Japan.

A total of 39 people have died in Vietnam, 19 of them sincethe H5N1 virus returned in December. Bird flu, which broke outin Asia in late 2003, has also killed 12 Thais and fourCambodians.

The Vietnamese Health Ministry has launched a campaign toraise public awareness and clean up the environment between nowand December to combat the poultry virus, which seems to thrivebest in the winter but jumps to humans in the hot months.