Veterinarians cull all sick ducklings and monitor other healthy poultry. (Photo: VOV))

The outbreak was detected at a poultry farm in Vinh Son commune of Vinh Linh district on June 2, with hundreds of 10-day old ducklings dying of unknown causes.

Local veterinarians took samples for testing and announced a week later that the ducklings had contracted the avian influenza subtype H5N1 that causes bird flu.

Local authorities culled all the sick birds and disinfected the farm and nearby neighbourhood. They closely monitored other poultry herds and banned the transport and trading in poultry products in the affected areas.