November 23, 2005
A critical phase in the evolution of a bird flu pandemic could play out in China in the coming weeks, according to a New Zealand expert. Robert Webster said a campaign in China to vaccinate its 14 billion poultry could precipitate a worst case scenario.
The doomsday scenario was that the Chinese would use a poor-quality vaccine that did nothing more than force the virus to mutate into something more lethal. "The international community has no way of knowing whether China will use a good one," Webster said.
"There is a big argument that they will simply help the virus to evolve to become a human pathogen," he said.
Meanwhile, China reported its second confirmed human death from bird flu. China's Health Ministry said the latest fatality -- a 35-year-old farmer -- died Tuesday after developing a fever and pneumonia-like symptoms following contact with sick and dead poultry.
The woman tested positive for the H5N1 virus, the official Xinhua News Agency said, citing the Chinese Center for Disease Control and Prevention.
China has provided few details about the vaccination campaign it has begun. It is even unclear if the birds are to be vaccinated against the bird flu strain - H5N1 - that has ravaged poultry stocks across Asia and killed at least 64 people since 2003.
For all the misgivings about the Chinese program, Webster said the international community should be doing more to vaccinate animals.
"There are good vaccinations available for agriculture that aren't being wisely used." Others were too weak, as animal vaccines were not subject to the same quality controls that applied to human vaccines, he said.
Even if the Chinese efforts did not precipitate the worst case scenario, that could still play out somewhere else in the world, Webster said.
The recent discovery of the virus in flamingoes in Kuwait indicated it was moving South toward Africa, which could provide the perfect environment for the critical mutation to human-to-human transfer.
"If it gets into the backyard flocks in Africa...that's a real worry," he said.
Even without such nightmare scenarios, the H5N1 virus was slowly accumulating mutations, he said. It has already picked up a genetic marker common to other killer viruses. The genetic marker has shown up in populations of geese in China killed by the virus, New Zealand media reported.
Some wild fowl from the same area had survived to migrate, potentially carrying the virus, Webster said.
