Veterinarians had controlled the bird flu outbreak in northern Thai Nguyen province, Vietnam Animal Health Department director Bui Quang Anh was quoted by the Vietnam News Agency as saying on January 4.

A flock of 350 two-month-old muscovy ducks at a farm in Song Cong town’s Luong Chau ward, less than 100 kilometres from Hanoi, died early this week and tests later confirmed they were infected with the deadly H5N1 virus.

Provincial veterinarians immediately culled the entire unvaccinated flock and disinfected the farm and its surrounds.

A veterinarian told Vietnam News that the vaccination of muscovy ducks had not been subsidised since mid 2007 and farmers had to pay for the injections themselves.

Vaccines for the species of duck were too expensive, not highly effective, and affected the birds’ development, he said.

Muscovy ducks were not as popular as other ducks and chickens in Vietnam.

Normally only 95% of birds in any given flock were vaccinated. The remaining 5% left show evidence of the virus.

Although vaccination prevented the virus from infecting birds, the virus still existed in the environment.

Scientists have warned that the possibility of new outbreaks is high with Tet, the Lunar New Year, only one month away, where poultry-smuggling was on the rise.

The Ministry of Public Health has 69 mobile teams in Vietnam’s 64 provinces and cities to prevent new outbreaks.

A boy, four years old, from Son La province died from bird flu in Hanoi last month and the virus had killed birds in six communes of Tra Vinh province.

Bird flu was first identified in Vietnam in late 2003 and has been reported from 23 cities and provinces deployed since last May.