Risk of avian influenza re-emerging during seasonal transitions

Strict control of the outbreak

At the end of August 2025, an avian influenza outbreak was recorded in Trung Hiep commune at the household of Nguyen Thanh Duy in Trung Hung hamlet. Within just a few days, hundreds of chickens died, forcing local authorities and the veterinary sector to urgently cull the remaining flock and implement containment measures.

According to the household owner, the flock of more than 1,600 bantam chickens was purchased from My Chanh Hoa commune (Vinh Long province) and vaccinated against avian influenza by the family when they were 25 days old. However, on August 25, the chickens stopped eating, showed wheezing, purple combs, and leg paralysis. The family tried to medicate them, but to no avail.

Just a few days later, the number of dead chickens rose rapidly, reaching approximately 300, prompting the household to report to the commune veterinary unit and the People’s Committee. On August 31, the Regional Livestock Production and Animal Health Station 2 collected samples and confirmed the appearance of the disease on the same day. By the morning of September 1, the Trung Hiep commune authorities and specialists had urgently implemented disinfection, isolation, and monitoring measures to prevent the spread to other farms.

According to the Vinh Long Sub-Department of Livestock Production and Animal Health, the source of the outbreak in Trung Hiep commune was likely due to improper vaccination practices. The household did not follow the correct procedure or recommended age for vaccination. The farming area also lacked adequate biosecurity measures. One thing to note is that erratic weather and sudden temperature changes reduced the birds’ immunity, creating an opportunity for the virus to invade and cause disease.

Nguyen Van The, Department of Economics, Trung Hiep commune People’s Committee, in charge of agriculture, said: “At the time the disease was detected, around 300 chickens in Duy’s household had already died. The remaining 1,340 chickens (weighing 495 kg in total) were also culled according to proper procedures.

Authorities instructed the farmer to clean and disinfect the poultry house. Health agencies coordinated with the local force to monitor the health of people in the outbreak area. At the same time, epidemiological investigations were conducted in and around the outbreak area, and disinfectants were provided for regular use.”

According to the Trung Hiep Commune People’s Committee, the chickens culled due to avian influenza will be proposed for compensation under Government Decree 116 (issued June 5, 2025) on support policies for livestock disease recovery, with a compensation rate of VND 35,000/kg. The Department of Economics is currently preparing documentation to propose support for this farmer.

Trung Hiep commune currently has 247 poultry-farming households with a total flock of 316,550 birds (175 households raising 265,500 chickens and 72 households raising 51,050 ducks). Among these, 10 large-scale farming households raise poultry under contract for enterprises.

Since the beginning of the year, the commune has strengthened disease prevention measures. The vaccination rate for avian influenza has reached 70.69%, with 223,800 birds vaccinated (171,600 chickens and 52,200 ducks). The commune also recently disinfected the livestock environment, spraying 120 liters of chemicals across 26 hamlets. Preparations are underway for the second vaccination session.

Strengthening prevention measures

Prior to Nguyen Thanh Duy’s case, another avian influenza (H5N1) outbreak occurred in Hieu Phung commune (Vinh Long province) with 2,450 poultry infected and destroyed. Since the beginning of the year, Vinh Long has recorded two avian influenza outbreaks, but thanks to prompt handling, the disease situation remains under control.

This year, the Sub-Department of Livestock Production and Animal Health plans to vaccinate 12.1 million poultry. A total of over 10.8 million birds were vaccinated in the first eight months of the year, reaching nearly 90% of the plan. Particularly in August 2025 alone, 300,250 birds were vaccinated against avian influenza.

However, vaccination work faces challenges, as livestock in the province is mainly small-scale and scattered (around 70–80%). In some localities, efforts to encourage vaccination remain limited, leading to low participation among farmers.

The Sub-Department no longer manages animal product businesses at markets, making it difficult to monitor these products. The trading and transport of animal products between regions are often run under the local veterinary force’s inspection radar, putting more pressure on the province’s disease control work.

Although two outbreaks have been controlled since the beginning of the year, the risk of re-emergence remains high, especially during seasonal transitions when high humidity and unstable weather create favorable conditions for avian influenza viruses to spread. To minimize damage and protect flocks, the provincial Livestock Production and Animal Health sector continues to monitor poultry diseases, carry out the second vaccination session, and supervise slaughtering activities at facilities.

According to Le Van Dong, Deputy Director of the Department of Agriculture and Environment, farmers must purchase quality poultry breeds with clear origins from reputable suppliers. This is a crucial factor not only for farming efficiency but also for effective disease prevention at the beginning of the crop.

It is also vital to apply biosecure farming practices and conduct vaccinations according to the recommended schedule by age. Regular cleaning, disinfection, and the use of lime powder and chemicals are needed to destroy pathogens.

“Farmers must monitor the health of their poultry daily to promptly detect unusual signs. When an outbreak occurs, they must not conceal it and immediately report it. Carcasses must not be discarded into the environment (rivers, canals, ditches). Farmers should cooperate closely with veterinary authorities for timely handling and rapid containment, thereby minimizing losses and preventing large-scale spread,” said Deputy Director Le van Dong.