The World Health Organization is calling for the rapid destruction of poultry infected with bird flu, to reduce the risk of spreading the disease to humans. The WHO has confirmed the deaths of five people in Vietnam from bird flu and two cases have just been confirmed in Thailand.
The World Health Organization says the spread of infection in birds increases the opportunities for direct infection of humans. The head of WHO's Global Influenza Department, Klaus Stohr, says dangers increase if human influenza and avian influenza are circulating at the same time.
He says this creates the possibility that the bird and human viruses might merge, making human to human transmission of the disease possible. He says this could start an influenza pandemic.
"There is a possibility that this avian virus merges as a human influenza virus and the resulting new strain would travel then very quickly around the world," he explained. "I have to emphasize that currently there is no indication that there is human to human transmission of this strain. There is no indication that this virus has already acquired genes from this influenza virus. There is no reason at this stage to think about human to human transmission."
Unlike SARS, which last year killed about 800 people, the bird flu virus is airborne. If this avian influenza mutated to allow human transmission, the World Health Organization says the consequences could be catastrophic. It notes that the great influenza pandemic of 1918-1919 caused an estimated 40 to 50 million deaths.
Dr. Stohr says there is still time to control the disease before it takes on global proportions. He stresses that countries must act decisively in halting the further spread of epidemics in poultry populations. He explains this would reduce opportunities for human exposure to the virus.
"One of the objectives for WHO is to avert a pandemic and the pathway to get there is to eliminate the animal reservoir," he said. "As long as there are animals which shed this virus which is known to cross the species barrier, there is a risk for the occurrence of a pandemic. This is the single most important intervention to reduce the public health risk."
Thailand and Vietnam already have killed millions of chickens. The European Union has just announced a ban on the import of Thai poultry, following similar bans by other countries including Hong Kong, Bangladesh and Japan. The crisis is threatening to destroy Thailand's multi-billion dollar poultry industry.
The World Health Organization says international scientists are working on a vaccine against bird flu. But the agency says it probably will take at least six months before a vaccine is developed and produced in sufficient quantities.