The bird flu virus has killed two more people in Vietnam and a boy in Thailand, bringing the death toll in Southeast Asia to at least 15. International health officials say the disease is spreading, and is probably not the newcomer it originally appeared to be.
World Health Organization officials say the bird flu virus has been in the region longer than previously thought.
They say it is more entrenched among bird populations, and as a result, there is a greater risk of it eventually spreading from human to human. So far, most or all of the human infections have resulted from people handling infected poultry.
WHO spokesman Peter Cordingley says that some of the recent discoveries of bird flu may be older infections that are just now being reported. He says the relatively low number of human victims so far means there is no cause for panic.
"Any talk of a pandemic is exceptionally premature," stressed Mr. Cordingley. "But still, the virus is on the move. We do not know where it is going to pop up next. I would say that as of today, we are losing more than we are winning."
The virus has been reported in two more provinces in China, raising the total of infected areas there to 12. Mr. Cordingley said this is a major concern because of China's vast population and the poor health care system in its rural areas.
"We would describe China as our area of main concern now. We still don't know what's going in large parts of the country," said the WHO official.
China's agriculture minister met with a WHO representative for the first time to discuss the outbreak. The organization has been pressing for more extensive information from China.
Mr. Cordingley says there are an estimated nine billion chickens in China - a lot of birds to examine. He reiterated the organization's position that there is no way to eliminate the threat of bird flu other than to destroy all the chickens in an infected area.
The virus has also been found in two more provinces in Thailand, where the government has killed nearly 30 million chickens. The Thai government says it has completed its culls in most provinces, and only nine provinces remain on the critical list. The rest are under surveillance.