Bird Flu Spate Signals Easier Transmission

Thailand has reported widespread outbreaks among farm poultry, and Vietnam, where all the fatalities have occurred in the last month, now counts bird or human infections in nearly half of its provinces.

The growing number of cases suggests that the virus may be mutating into a form that is more easily transmitted to and among humans, increasing the possibility of a pandemic.

"The situation in Southeast Asia right now is the most significant setup for a very serious public health crisis that I've seen in my 30 years in this business," said Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. "We're sitting on a time bomb."

Vietnamese officials have struggled to contain the virus, deploying riot police at some checkpoints around Ho Chi Minh City to prevent an influx of infected birds during this month's Lunar New Year celebrations.

The government has destroyed more than 1 million domestic poultry in an effort to control the outbreak. But the virus has become so widespread that the mass slaughter of birds has been abandoned in some infected areas.

Since July, about 1 million birds have died or been culled in Thailand, compared with about 40 million culled during the first few months of last year.

Authorities believe the virus has a natural reservoir in wild fowl, which continually reinfect domesticated flocks.

Fear of avian flu has become pervasive in the region. People in China, including Hong Kong, as well as in Japan and Thailand have begun to snap up supplies of Tamiflu, the one drug that is effective in suppressing the virus.

If Switzerland's Hoffman-La Roche, Tamiflu's only supplier, tripled production, it would still take it six months to make enough to supply 1 million people for five weeks, said Dr. Klaus Stohr, head of the World Health Organization's global influenza program.

The strain of avian flu affecting Southeast Asia, known as H5N1, emerged in Hong Kong in 1997.

But it has spread rapidly in the last year, killing 44 people out of the 58 infected in Vietnam and Thailand, according to the WHO and the Vietnamese government.