The risk of a flu pandemic remains high despite possible public fatigue with the issue, but the World Health Organization is hopeful the bird flu virus will do less damage than in past years during Asia's upcoming colder months, an official said Sunday.

"The virus seems to be very embedded in the environment and, in our view, the risk of a pandemic continues unabated," Richard Nesbit, WHO's acting regional director for the Western Pacific, told reporters prior to a weeklong meeting in Auckland, New Zealand.

"Recently, we've seen new outbreaks in poultry in Cambodia and also in Thailand, besides seeing continuing outbreaks in Indonesia," he said.

Bird flu is expected to be one of the top items discussed for the third straight year at the annual WHO regional meeting, which helps set the organization's strategic agenda. The H5N1 virus has killed at least 144 people since it began ravaging Asian poultry stocks in late 2003, and experts worry more fatalities will emerge as the cooler months approach.

Nesbit said he's encouraged by the progress Vietnam has made in beating back the virus. The communist country has recorded the second-highest number of fatalities after Indonesia, but has not detected a human case since November 2005. Vietnam has credited its success to a mass vaccination campaign of poultry and strong political will.

"I think that we've made a lot of effort in building up capacity in other countries, so I'm also hopeful that we will see a much improved situation (and) that we will not get human cases," he said of the cooler weather, when bird flu outbreaks and human cases are often logged.

Bird flu remains hard for humans to catch, but experts fear the virus could mutate into a new form that spreads easily among people. So far, most human cases have been traced to contact with infected birds, but Nesbit said the public should not lower its guard even though the warning has now become somewhat old.

"The scientists are telling us that the risk is just as present as ever. ... We are seeing continuing evolution of these viruses and that's been very well documented now both in humans but as well also in poultry," he said. "After three years now, I'm sure that many journalists and the public are starting to get tired of the same message that there's a potential global pandemic around the corner, but we have a responsibility to continue to give this message."

In Singapore, officials from the World Bank and United Nations expressed worry on the sidelines of the bank's annual meeting about bird flu in Africa and Asia, particularly China and Indonesia.

Last week, David Nabarro, the U.N.'s point man on bird flu, said he would push for donors to give more money to help Indonesia, which has been hit by a string of bird flu cases and has become the worst-hit nation with 49 human deaths.

The WHO meeting in New Zealand, attended by 37 countries and territories, also will address a number of other major health issues affecting the region, including heart disease, diabetes, AIDS and tuberculosis. Smoking and alcohol control also will be discussed, along with the migration of health care workers throughout the region.