The H5N1 virus has affected poultry production and had severe negative consequences on consumption of poultry and on employment in industries processing and retailing poultry products.The regional impact has been uneven, with some areas losing more than 50 percent of their poultry. Various levels of assistance, in the form of compensation and credit, have been provided.Control of the H5N1 virus is a complex task; it is essential to reduce the amount of virus circulating in poultry and in farm environment. Surveillance for early diagnosis and reporting, particularly to national Ministries of Agriculture and the World Organization for Animal Health (OIE), is key to success and must be optimized.
No single set of measures fits all countries. Consequently multiple strategies should be used. Virus control strategies range from culling and eradication to vaccination.Control measures must be based upon sound science and good disease management principles and adapted to the local situation.National authorities are responsible for implementing strategies that respond to local conditions, based on epidemiological, biological, economic, political and social factors.The main measures available to prevent, control and eradicate the avian influenza virus are:
- Effective disease surveillance for early detection and reporting of outbreaks.
- Enhanced biosecurity of poultry farms and associated premises.
- Control of movement of birds and products that may contain virus, including controls at the interface of infected and uninfected areas.
- Changes to industry practices to reduce risk.
- Rapid, humane destruction of infected poultry and poultry at high risk of infection.
- Disposal of carcasses and potentially infective material in a biosecure and environmentally acceptable manner.
- The proper use of vaccination.
All of these control measures reduce risk but none used in isolation is sufficient. All available measures should be discussed by government with the private sector and other stakeholders, to determine the best combination of control measures.
When outbreaks of H5N1 or other highly pathogenic avian influenza viruses occur, immediate stamping out is the most appropriate and the first response of veterinary authorities. Stamping out must be accompanied by movement control, proper disposal of carcasses and other potentially infective material, and cleaning/disinfection of affected farms and associated premises. Controls on the movement of birds and poultry products between countries should be based on OIE recommendations, which provide the basis for safe international trade.In countries that have reservoirs of HPAI viruses in wild birds or domestic waterfowl, control measures must focus on preventing these viruses from entering the domestic chicken population. FAO recommends against the destruction of wild birds or their habitat. Rather, farm biosecurity must be enhanced.
Vaccination can be used as a tool to support eradication or to control disease due to HPAI and to reduce the viral load in the environment. Where it may not be feasible or desirable to proceed with massive culling, targeted vaccination may be the most appropriate means of ‘dampening down' an HPAI outbreak. Where farm/village/backyard biosecurity cannot be improved and where there is significant challenge from HPAI viruses, including infection in neighbouring villages, wild birds, domestic ducks or bordering countries, veterinary authorities should consider vaccination strategies to minimize propagation by this sector, to protect susceptible birds from infection and to manage human health risks. Source: FAO Recommendations on the Prevention, Control and Eradication of Highly Pathogenic Avian Influenza in Asia