With three new bird flu deaths confirmed during the week, the UN-affiliated World Health Organization expressed concern about the high fatality rate - more than 70 percent of those infected have died - and the lack of research to answer critical questions about how it is transmitted, especially since no vaccine or effective treatment exists.

"We have got to be very careful that we do not lose sight of, or control of, the bird flu health threat which could have much greater public health implications than the tsunami," said William Aldis, the WHO's top representative in Thailand.

Human cases generally have been traced to direct contact with sick birds.

But as more human bird flu cases occur, the chances become greater for the deadly virus to acquire more ability to be transmitted from person to person.

"If we continue to experience these frequent new outbreaks with the virus spread both in poultry and people, it finally might result in an awful virus strain that could become a pandemic with a horrendous outcome," said Hans Troedsson, WHO's representative in Viet Nam.

"The more frequently we get outbreaks, the higher risk we have to infect." Viet Nam has reported seven bird flu deaths since December 30. The latest victim marks the first death in northern Viet Nam and brings the toll to 27 in Viet Nam over the past year. In Thailand, 12 people died of the disease last year.

(China Daily January 22, 2005)