Bangkok, Thailand ? Thailand’s prime minister said Saturday the bird flu epidemic could hurt the country’s giant chicken export sector, as Vietnam confirmed that a sixth person had died from the disease.

After weeks of denial, Thai officials acknowledged the virus’ presence as poultry farmers claimed not enough was being done to stop the disease from spreading from nearby countries.

Vietnam and Thailand are the only countries this year where avian flu has been passed on to humans. But the virus has hit millions of chickens, raising fears it might mutate, link with regular influenza and foster the next human flu pandemic.

Asia is on a regionwide health alert, with governments slaughtering millions of chickens to contain outbreaks in six countries: Thailand, Vietnam, Cambodia, South Korea, Japan and Taiwan.

The World Health Organization confirmed two new cases of bird flu in southern Vietnam’s Ho Chi Minh City, which had not reported any patients.

One of the cases — a 13-year-old boy — died Jan. 22, while the virus also has sickened an 8-year-old girl, who is in a critical condition. Five others died earlier in Vietnam while a 56-year-old Thai man believed to have avian flu died Friday.

In a weekly radio address, Thai Prime Minister Thaksin Shinawatra acknowledged Saturday that the onset of the virus in Thailand could devastate the country’s chicken export sector — the world’s fourth largest.

Thailand shipped about 500,000 tons of chicken worth $1.3 billion in 2003. But on Friday the European Union and Japan — Thailand’s biggest markets for poultry — announced bans along with a host of countries because of fears about the spreading virus.

An employee removes packs of chickens imported from Thailand from shelves at a supermarket in Nagoya, central Japan. Japan has banned Thai chicken imports because of the proliferation of bird flu in Thailand.

Thaksin said overall exports could drop by up to 0.4 percent and gross domestic product could slip by as much as 0.1 percent.

“If they are going to stop buying, we have to deal with it,” he said. “This is the worst-case scenario.”