Avian influenza (AI), also known as bird flu, remains a major challenge to the poultry industry in Asia despite the availability of vaccines. HA THU and the Asian Agribiz team learn that countries in the region have been trying their best to overcome challenges posed by the viral disease.
In Indonesia, AI remains a concern for the poultry sector, according to Fauzi Iskandar, Veterinary Service Manager at Ceva Animal Health Indonesia.
He told Asian Agribiz that AI virus subtypes H5 and H9 are endemic in the country, similar to H5N1 clade 126.96.36.199c and H9N2 strain Y280. He observed a rise in H9N1 cases in the last three months among commercial broiler and layers.
AI is also endemic in Vietnam. In the first 11 months of this year, more than 31 provinces and cities reported AI outbreaks with more than 400,000 birds culled.
The most common AI virus strains in Vietnam include H5N1 and H5N6. However, the industry is on high alert for H5N8 from chicken imported illegally.
Quality of vaccine and vaccination
Many reasons contribute to AI outbreaks in the region, but some of them are related to the low quality of the vaccines and ineffective vaccination at farms.
Vietnam produces AI vaccines that can work against several virus strains. However, “AI virus mutates quickly, so the vaccines should be developed accordingly to be effective against the circulating strains,” said Trung Huynh, Poultry Unit Manager at Ceva Animal Health Vietnam.
On-farm vaccination is challenging as backyard farms still account for majority of poultry production like in Vietnam. “The outbreaks often occur in small farms, where farmers don’t vaccinate their flocks. If they do, they buy poor quality vaccines that don’t offer sufficient protection,” Nguyen Van Quy, Technical Director at Luong Hue Poultry Breeding Company, told Asian Agribiz.
The same situation is apparent in Indonesia, where backyard chickens, ducks, and other poultry are not 100% vaccinated. “Even if the flocks are 100% vaccinated, the quality of the vaccination is not good enough to support the immunity of the birds. Farmers must use the correct vaccine and administer it properly,” said Mr Iskandar, adding that AI vaccines are more effective if applied at hatchery.
Nevertheless, vaccination alone is insufficient to control AI. “Strict biosecurity rules and proper hygiene are essential for an effective prevention program,” Mr Iskandar stressed.
In July 2020, OIE published the list of 100 AI-free compartments in Indonesia.
Due to the implementation of AI-free compartmentalization, the number of AI cases in Indonesia has decreased drastically. Some export markets, such as Japan, Qatar, Timor-Leste, and Papua New Guinea, now import Indonesia’s poultry and its processed products.
“We continue to invite more poultry producers to get the compartment-based AI-free certification,” said Nasrullah, Director General of Livestock and Animal Health at the Agriculture Ministry.
In the Philippines, compartmentalization and zoning are included in the country’s Avian Influenza Protection Program Manual of Procedures.
Also in Vietnam, there are some compartmentalized farms built in accordance with OIE’s guidance and are certified as AI-free poultry production area. Those farms are built to produce chicken meat for export.
According to Mr Iskandar, eradicating is possible. However, it may take a long time for Indonesia.
Likewise, Vietnam’s poultry industry finds it difficult to completely wipe out AI. “It is difficult because of the natural habits of livestock production in the country. Backyard farming is still dominant in the industry’s structure, and it is challenging to have vaccine coverage at backyard farms,” said Mr Quy.
In addition, the fact that Vietnam shares borders with many countries poses a risk of disease transmission via illegal trans-border trading activities.
Lessons from AI-free countries
The Philippines and Thailand are two countries in Southeast Asia that have AI-free status.
Arlene Vytiaco, Veterinarian IV at the Bureau of Animal Industry told Asian Agribiz, “it is possible to eradicate AI. We have conducted eradication program during past outbreaks in 2017 and 2020.”
In 2017, the Philippines applied several control measures including depopulation of all avian species within 1km around the index case, movement control, strict biosecurity measures, and intensive surveillance activities.
“In 2020, we modified some of them such as selective depopulation wherein only the affected farm is depopulated but culling is simultaneously done with surveillance within the 1km quarantine area. Those testing positive will be culled as well,” Dr Vytiaco explained.
In Thailand, preventive measures are key to making Thailand AI-free for more than 10 years. Sorravis Thaneto, Director General of the Department of Livestock Development (DLD), said the measures include strict biosecurity, regular cleaning and disinfecting of poultry houses and outside areas, farm safety, controlling movements in and out of the farm, and vehicle disinfection.
“When we are alerted of unusual deaths of poultry or suspected AI cases, DLD officials proceed to investigate and implement disease control measures immediately,” Mr Sorravis explained.
The DLD also strictly monitors animal disease at the border and asks poultry farmers to observe bird symptoms closely, and warns farmers to be vigilant following outbreaks in Europe and Asia.