Vietnam on alert against avian influenza H5N1

Typical lesions include hemorrhages in the pericardium, liver, spleen, and kidneys. The virus spreads rapidly through wild birds, farming equipment, vehicles, and direct contact within flocks.

AI remains a threat

In Vietnam, the first H5N1 outbreak was detected in 2003, leading to the culling of more than 56 million poultry. From 2003 to 2022, human infections were also reported, with a mortality rate of up to 50%.

Despite significant progress in prevention and control, sporadic outbreaks still occur.

Between 2023 and mid-2024, around 20 outbreaks were reported in Bac Ninh, Ninh Binh, Tien Giang, and Long An, resulting in the culling of over 6,000 birds. The risk of outbreaks is highest during the winter-spring season (December to March).

According to Nguyen Thi Thuy Tien of the Vigova Poultry Research and Development Center (National Institute of Animal Science), poultry infected with H5N1 often display lethargy, anorexia, greenish-white diarrhea, convulsions, circling movements, and even paralysis.

Post-mortem examinations commonly reveal pericardial fat hemorrhage, swollen and hemorrhagic liver, spleen, and kidneys.

Effective prevention measures

Proactive prevention is key. Main measures include:

• Vaccination: Administer full vaccination as instructed, with regular boosters. Birds should only be sold at least 14 days after vaccination.
• Biosecurity: Secure farms with fences, disinfection pits, and warning signs; keep feed storage dry; isolate new flocks; avoid mixed-species farming; prevent contact with wild birds.
• Hygiene and disinfection: Carry out daily cleaning and leave poultry houses empty for at least 20 days before restocking.
• Nutrition: Provide sufficient vitamins and minerals to strengthen immunity, especially during seasonal transitions.

If unusual poultry deaths are detected, farmers must immediately notify veterinary authorities. Carcasses should never be discarded into the environment or sold.

AI not only causes economic losses but also poses a serious public health threat. Therefore, close cooperation among farmers, businesses, and authorities, combined with vaccination and strict surveillance, is essential to protect flocks, ensure sustainable livestock production, and safeguard food security.