PHNOM PENH - CAMBODIA'S Health Ministry confirmed on Friday the country's eighth human case of virulent bird flu since 2005.

The ministry said in a statement with the UN's World Health Organisation that a 19-year-old man from Kandal province, south-east of the capital Phnom Penh, was confirmed to have the deadly H5N1 strain of the virus in laboratory tests on Thursday.

The case, the first this year in Cambodia, comes a day after a senior World Health Organization official warned that Asian nations must remain vigilant against the disease.

The WHO says there have been 246 confirmed fatal cases of the disease in humans worldwide since 2003.

The man is being treated at Calmette Hospital in the capital.

Cambodian health and agriculture ministry officials have been sent to the victim's village to ensure that there is no further spread of the disease.

Ly Sovann, a health ministry expert on bird flu, said the victim became sick after touching a dead chicken that had been raised at his home.

'The boy is being treated at hospital now but his health is getting better day by day,' Mr Ly Sovann said. 'If nothing changes with his health, he will be released from hospital soon.' The seven previous Cambodian victims of the disease had died.

On Thursday, the WHO's regional chief urged Asian governments not to let down their guard against bird flu, saying a new outbreak among poultry in Hong Kong showed the disease still poses a threat.

'This is an indication that we have to remain vigilant,' Shigeru Omi said in Malaysia. 'Constant vigilance is the key.'

Mr Omi said the outbreak in Hong Kong was 'not unexpected because the virus is still circulating in the world, and certainly in this part of the world.'

Twenty countries had outbreaks of the disease during the first nine months of 2008, down from 25 during the same period last year, UN officials have said.

Some officials worry that the public has largely lost interest because the virus has so far not mutated into a much-feared form that could spread easily among people. It remains hard for people to catch, with most human cases linked to contact with infected birds. -- AP