The outbreak of Highly Pathogenic Avian influenza (HPAI) of the H5N1 virus subtype was first reported in Thailand in January 2004. It widely spread throughout the country causing severe morbidity and mortality in poultry, restrictions of domestic and international trade of poultry products, and impacts on farmers’ livelihoods and socioeconomics. From 2004-2006, Thailand had experienced four waves of HPAI outbreaks, the first wave resulted in 320,000 birds culled, the second wave 63 million birds culled, the third wave 450,000 birds and the fourth wave resulted in a limited number of culls. The disease has major social and economic impacts, from Jan-Jul 2004, HPAI outbreaks cost Thailand 54 billion baht and affecting 1.2 million people. The disease is also a potential threat to a global human influenza pandemic with 25 infected human cases and 17 death reported in Thailand. Avian influenza virus (AIV) is highly contagious, infected birds shed viruses in high concentration in cloacal and nasal discharge. The virus can spread from flock to flock through the movement of infected birds, farm equipment, egg cartons and feed, farm workers, and etc. Controlling HPAI at source is the essential prerequisite for protecting Thai farmers and poultry industries and ensures a safety of poultry products for consumers.
The Department of Livestock Development (DLD) has direct responsibility to control and mitigate HPAI. DLD has developed the National Strategic Plan for AIV prevention and control by assigning the responsibility of averting and potential eradication of HPAI to National Institute of Animal Health (NIAH), seven regional VRDCs and DLD network of veterinarians. Before this project, the seven VRDCs were mainly responsible for laboratory diagnostics and epidemiology, but following HPAI outbreaks, regional VRDCs’ responsibilities also included containment of the disease by implementing rapid diagnosis and management of future outbreak risk. DLD has strictly implemented a stamping-out policy (i.e. culling of all flocks within 5 kilometer radius of confirmed cases) with compensation and other control measures (i.e. movement restriction, disinfection), to eradicate the disease. A use of vaccination against HPAI is prohibited in Thailand.
Some 20 percent of total poultry agribusiness in Thailand resides in the Eastern region (9 provinces and a population of 5.2 million). In addition to several large commercial farms, poultry meat processing, parent stock and feed mills, there are many small-scale poultry farmers who raise native chickens, fighting cocks and free-grazing ducks (the latter are reservoirs of infection), and these activities are essential source of income in the form of direct sells and job opportunities. Initially, DLD’s official containment policy has led to low uptake of control measures and the less willingness from smallholder poultry producers in the region to report potential “new cases”. This low uptake was exacerbated by the farmer’s lack of knowledge on HPAI transmission pathways and the poor access to appropriate veterinary services and mixes of different poultry species. All these factors greatly increased the risk and spread of AI and thus provided an option for EVRDC to implement better veterinary service in order to control HPAI outbreaks systematically.