In the first outbreak in poultry in Vietnam this year government officials say the H5N1 bird flu virus has killed 350 white-winged ducks in the north of the country.
The virus was detected at a farm in Thai Nguyen province in young ducklings and the Animal Health Department have slaughtered all the remaining birds on the farm in efforts to prevent the virus spreading.
In Vietnam's first human case in nearly five months the deadly virus claimed the life of a four-year-old boy in December from an ethnic minority group in the northern province of Son La.
At that time the government said the virus had infected hundreds of ducks and chickens in the Mekong Delta province of Tra Vinh in the south which along with Thai Nguyen remains on the government's bird flu watchlist.
As investigations failed to find any indication of the H5N1 virus in or around the area where the boy died the suspicion is that wild birds may have spread the bird flu virus.
The boy's death from bird flu has been confirmed by the World Health Organization (WHO) which now brings the death toll to 47 of the 101 people infected in Vietnam since late 2003.
Experts say cold weather currently affecting the northern provinces, along with a rising demand for poultry ahead of the Lunar New Year festival early next month could exacerbate the spread of the H5N1 virus, which thrives best in cool temperatures.
To date, according to the WHO, the H5N1 virus has killed 212 people out of 343 known cases, with most of the deaths in Indonesia, Vietnam, Thailand and Egypt.