Vietnamese authorities have detected the H5N1 avian flu virus in a flock of ducks on a farm in the southern province of Ca Mau, a government official said Friday.
Hoang Van Nam, deputy director of Vietnam's Animal Health Department, said inspectors had found on September 22 that bird flu had killed more than 50 of 500 ducks on a Ca Mau farm, reported dpa.
All the ducks at the farm were ducklings under 45 days old, and had thus not been vaccinated yet, Nam said.
Authorities have culled all the ducks at the farm.
"Bird flu occurs occasionally in Vietnam," Nam said. "We cannot extinguish it, but only limit its spread."
On September 7, the Animal Health Department announced it had detected bird flu in a flock of 600 ducks on a farm in the southern province of Ben Tre, adjacent to Ho Chi Minh City.
According to Nam, bird flu outbreaks have been detected in 26 Vietnamese provinces since the beginning of 2008, killing 5 people and forcing authorities to cull more than 60,000 ducks.
H5N1 mainly affects poultry and wild birds, but can infect humans who have close contact with sick fowl. Scientists fear that if it spreads unchecked, the disease could mutate into a form which could be transmitted between humans, leading to a worldwide pandemic that could kill millions.
Bird flu has infected 105 people in Vietnam and killed at least 51 of them since it first appeared in the country in late 2003.