Monitoring and controlling avian influenza at its poultry source is essential to decrease the virus load in susceptible avian species and environment. Implementation of biosecurity measures, in line with OIE international Standards, is a key to secure the production sector and trade, to safeguard food security and the livelihoods of farmers, in particular in developing countries, as well as to limit the risk of human infection with Avian Influenza strains that have zoonotic potential.
The first line of defence against avian influenza is the early detection of disease outbreaks followed by a rapid response. This is strongly linked to a high level of awareness among veterinarians and animal owners, and high quality Veterinary Services. Putting in place accurate warning systems as well as prevention measures is essential as part of an effective strategy to prevent and control avian influenza. This needs to be coupled with similar efforts placed on preparing for a potential outbreak.
Avian influenza is a notifiable disease listed by the OIE. As detailed by the OIE Terrestrial Animal Health Code, Member Countries must report:
Unusual mortality among wild birds should also be reported to the OIE through its World Animal Health Information System (WAHIS).
Because of the stability of the virus in the environment and highly contagious nature, strict biosecurity measures and good hygiene are essential in protecting against disease outbreaks.
If the infection is detected in animals, a policy of culling infected and contact animas is normally used in an effort to rapidly contain, control and eradicate the disease.
Requirements include (and are described in the OIE Terrestrial Animal Health Code):
When outbreaks are detected, stamping out is generally applied at the level of the infected farm or within a short radius around the infected premises in conjunction with active surveillance.
Controlled elimination of infected poultry, movement restrictions, improved hygiene and biosecurity, and appropriate surveillance should result in a significant decrease of viral contamination of the environment. These measures should be taken whether or not vaccination is part of the overall strategy.
Systems of financial compensation of farmers and producers who have lost their animals as a result of mandatory culling ordered by national authorities vary around the world; unfortunately they may not exist at all in some countries. The OIE encourages national authorities to develop and propose compensation schemes because they are a key incentive to support early detection and transparent reporting of animal disease occurrences, including avian influenza.
It is important that vaccination alone is not considered the solution to the control of avian influenza if eradication is the desired result. Without the application of monitoring systems, strict biosecurity and depopulation in the face of infection, there is the possibility that these viruses could become endemic in vaccinated poultry populations. Long-term circulation of the virus in a vaccinated population may result in both antigenic and genetic changes in the virus and this has been reported to have occurred in several countries.
Vaccination should be implemented for a limited duration when culling policies cannot be applied because either the disease has become endemic and therefore widespread, or the infection in affected animals is too difficult to detect.
When appropriate vaccines complying with OIE quality standards are available, vaccination is used to protect susceptible poultry populations from potential infection. Vaccination strategies can be effective as an emergency measure in an outbreak or as a routine measure in an endemic area.
Any decision to use vaccination must include an exit strategy, i.e. conditions to be met to in order to stop vaccination.
In 2006, the OIE set up a regional Vaccine Bank for avian influenza vaccines, which was the first OIE Vaccine Bank to be developed. A total of 62,017 million H5N2 vaccine doses were delivered to countries around the world. Today, the OIE avian influenza Vaccine Bank is closed, but it has paved the way for the creation of foot-and-mouth disease (FMD),rabies (vaccination of dogs), and peste des petits ruminants (PPR) Vaccine Banks.