Cambodia´s health ministry on Wednesday officially confirmed that the woman died in Vietnam last month was killed by bird flu.

    "Samples taken from the woman were sent to Pasteur Institute in Ho Chi Minh City for testing and they were confirmed positive for avian influenza A/H5 virus," said a joint statement of the Health Ministry and the World Health Organization (WHO).

    The 20-year-old woman was from Kompong Trach district in Kampotprovince, the same district as the first case reported in February. She died on April 19 in a hospital in Vietnam.

    She was a secondary school student who also ran a small business selling food, including chicken, to neighbors in her village of residence.

    No poultry deaths with patterns of mortality indicative of avian influenza were reported in her village, according to the statement. But the investigations at the school found that poultrydeaths began occurring in late March/early April and were continuing into Khmer New Year.

    "The woman was likely to have been exposed to the virus in the village of her school," it added.

    The woman has been the fourth person killed by bird flu in Cambodia since January. Cambodia´s third bird flu victim was a 8-year-old girl who died on April 10 at a hospital in Phnom Penh.

    And the second bird flu victim, who died on March, was a 28-year-old man and the first one was a 25-year-old woman who died in Vietnam´s hospital and lived only 20 km away from the second victim.

    The four were all from Kompot province bordering Vietnam.

    Public education in Kampot province is on-going and the government is calling for support from public and private health care workers in detecting and responding to suspected cases of avian influenza.