HANOI/BEIJING - BIRD flu has killed a woman teacher in northern Vietnam, the fourth death from the H5N1 virus this year, state-run Voice of Vietnam radio reported.

The 23-year-old woman died on Monday at a Hanoi hospital after falling sick as she ate chicken in her home province of Phu Tho, the radio quoted the Health Ministry as saying on Tuesday.

In communist-run Vietnam, official announcements are often made in state-run media.

The woman's death is the fourth out of five people infected by bird flu so far this year in Vietnam after an extended cold spell in northern provinces. The virus is usually most active in colder weather.

A 7-year-old child from the northern province of Hai Duong who has been confirmed as infected by the H5N1 virus remained under treatment at a paediatric hospital in Hanoi, doctors said.

Excluding the death on Monday, bird flu has killed 232 people among the 366 known cases globally, among them 50 deaths in Vietnam, the WHO said.

In China, a bird flu outbreak in poultry has been reported in the south-western province of Guizhou, state media said, the same day a woman died from bird flu in the south.

The poultry outbreak, which was first noticed on Feb 17 in the city of Zunyi, had killed 3,993 birds and triggered the culling of more than 238,000 birds, Xinhua said late on Monday, citing the Ministry of Agriculture.

China has reported four outbreaks of the disease in poultry since December, when average temperatures across the country hit their lowest in decades.

With the world's biggest poultry population and hundreds of millions of farmers raising birds in their backyards, China is seen as crucial in the global fight against the disease.

China has also reported three confirmed human deaths from bird flu this year, in central Hunan province, the southern region of Guangxi and the latest in southern province of Guangdong. -- REUTERS