HANOI (AFP) - A Vietnamese student has died from the H5N1 strain of bird flu, the country´s fourth victim of avian influenza this year, state media reported on Tuesday.

The 15-year-old victim´s family had kept ducks at their home in Thanh Hoa province south of the capital Hanoi, the state-run Vietnam News Agency reported.

The death, which could not immediately be verified with government officials, would bring to 46 the number of people who have died of bird flu in Vietnam since the killer virus broke out here in late 2003.

Communist Vietnam, once the nation worst hit by bird flu, contained earlier outbreaks through mass vaccination campaigns, the culling of millions of poultry and public education initiatives.

But the virus resurfaced strongly earlier this year, especially among waterfowl, hitting scores of poultry farms in an outbreak that at its peak in May spread to 18 of Vietnam´s 64 provinces and municipalities.

As of this week, only three provinces remained affected, and 160 million head of poultry had received bird flu shots in the year´s first round of vaccinations which was ongoing or finished in all provinces, officials said.

The World Health Organisation (WHO) had recorded 319 cases of bird flu in humans worldwide, 192 of which were fatal. The Geneva-based body has yet to confirm the latest death in Vietnam with laboratory tests.

Experts fear the global death toll could rise sharply if the virus were to mutate and become easily transmissible between humans, leading to a global pandemic with the potential to kill millions.

Last week WHO spokesman Gregory Hartl said global bird flu cases appeared to have stabilised among humans but that several developing nations had not been able to stem its spread among poultry and domesticated birds.

"The number of human cases of bird flu appears to be stable when compared to the same period last year," Hartl said. "In the northern hemisphere, the number of cases in summer has declined marginally from the winter.

"Human to human transmission are very rare. We think there have been three cases -- in Vietnam, Cambodia and Indonesia. And each time the person has had prolonged and direct contact with an affected person," Hartl said.

World Bank vice president for East Asia and the Pacific James Adams, speaking earlier Tuesday during a visit to Hanoi, warned that the bird flu threat remained.

"The magnitude of the challenge in this region is exceptional because this is a region where livestock lives in close proximity to the human population," he told a Hanoi media briefing.

"We are trying to emphasise from the development side that the needs of the veterinary systems and the health systems do need to be pushed and have to be reinforced."