A four-year-old boy became the latest casualty of bird flu in Vietnam, bringing to five the number of people to have died from the avian virus this year in the region, health ministry officials in Vietnam confirmed Thursday.

Tran Hung, Vietnam's health ministry administrative office director said, "He tested positive to the H5N1 virus late last week. It is the first human case of H5N1 in about four months in Vietnam."

The unidentified boy was from the town of Moc Chau, in the mountainous northern Son La province. He was admitted to a local hospital on December 11 after developing high fever and pneumonia.

Hung said the boy was transferred to children's hospital in the capital Hanoi on December 14 where he died two days later.

"His relatives told us he had eaten chicken meat and that some dead chickens had been found around his family home recently," Hung said.

The boy's death brings to 47 the total number of people to have died from the avian virus since the disease was first detected in late 2003 when the virus first hit poultry flocks in South east Asian countries.

Statistics from the World Health Organization showed that at least 209 people have died from the H5N1 virus across the globe. Although human-to-human transmission is still not reported, health experts believe the virus could mutate into a form that spreads easily among humans, which could spark a global pandemic.