HANOI, Vietnam -- The World Health Organization credited SARS for helping Asia prepare for a flu that has killed millions of chickens and at least three people, while governments struggled Friday to contain the virus with further curbs on poultry imports and culls of sick birds.
A minister in Thailand angrily denied that his government was covering up a major outbreak of the avian flu, while WHO officials worked to figure out how the disease jumped to people in Vietnam - where the three reported deaths from the illness occurred.
The H5N1 strain of bird flu has hit poultry farms hardest in Vietnam, South Korea and Japan, prompting authorities to order the slaughter of millions of chickens.
Asian governments have worked quickly to try to curb the virus, and the WHO's Vietnam representative Pascale Brudon attributed that in part to last year's major outbreak of severe acute respiratory syndrome.
"I can see there is increased awareness of the need for good surveillance, the need for acting urgently when we have a problem. I think this is a ...positive aspect and a lesson learned from SARS, which has helped us in this new crisis," Brudon said in Hanoi.
Vietnamese officials have enacted several measures to combat the spread of the flu, including banning the transportation of poultry between provinces and ordering farmers to destroy infected flocks.
On Friday, authorities in Ho Chi Minh City, the country's largest, imposed a temporary ban on all poultry sales in an effort to limit further flu infections.
The city government has also offered to buy off the estimated 1.1 million chickens citywide from farmers at 96 cents each. Farmers had balked at destroying chickens that were their livelihood.
"We have to act decisively to prevent the possible spread of the disease to the city," said Nguyen Phuoc Thao, deputy director of the city's department of agriculture and rural development.
In Taiwan, health workers donned surgical masks and blue suits Friday to dispose of 20,000 chickens infected with a milder variant of the virus hitting the other Asian countries. Officials on the island said the H5N2 strain poses little threat but that they wanted to avoid possible mutations and other risks.
Not taking any chances, Hong Kong moved to bar poultry imports from Taiwan.
The Chinese territory, plus China's mainland and Cambodia already have halted poultry imports from Vietnam, South Korea and Japan. Indonesia barred poultry imports from those three countries on Friday.
The H5N1 virus is the same one that jumped to people in Hong Kong in 1997, killing six.
The deadly virus - highly contagious among chickens - has not shown any human-to-human transmission, and is believed to spread to humans through contact with infected birds. Health officials say if it mutates and mixes genetic material with a human flu virus it could become contagious in humans, sparking a major health crisis.
Government officials have sought to calm fears about eating poultry products, saying there is no danger if the public properly cooks the meat and eggs of chickens.
In Taiwan, a county official insisted local birds are safe. To prove his point, he appeared on ETTV news, cracking an egg in his hand and slurping the yolk. "It tastes good and it's very nutritious," he said.
In Thailand, farmers and a consumer group have charged for several days that millions of chickens have been infected by the bird flu and that the government is covering it up. But the government insists the outbreak there is bird cholera - not bird flu.
"Irresponsible media and some groups of people are trying to spread this rumor," Deputy Agriculture Minister Newin Chidchob told reporters Friday. "There is no bird flu here."