Samples from the man in Vinh Long province suffering from fever, cough and pain chest were now being tested for the H5N1 virus at the Pasteur Institute in Ho Chi Minh City, the Thanh Nien (Young People) daily said.

It did not say on how he fell sick.

The Health Ministry has warned bird flu could spread during and after this week's Lunar New Year festival when chicken is consumed in vast quantities. In addition, winter creates an ideal environment for the avian influenza virus to thrive.

Vietnam has this year confirmed one case of human infection in the northern province of Thanh Hoa, involving a 8-year-old girl who fell sick after having eaten duck and chicken raised on the family farm. She has recovered.

The H5N1 flu remains largely a virus among birds, but experts fear it could mutate into a form that is easily transmitted by humans and spark a pandemic that could kill millions worldwide.

Having resurfaced in Asia in late 2003, the virus has infected 399 people worldwide and killed 252 of them, including 52 in Vietnam, according to the World Health Organization.

By Ho Binh Minh - Reuters - January 31, 2009