Update on Highly Pathogenic Avian Influenza Control Methods in Asia Including Use of Vaccination
27 September 2004, Rome – The avian influenza epidemic in Asia is a “crisis of global importance” and will continue to demand the attention of the international community for some time to come, the UN Food and Agriculture Organization (FAO) and the World Organisation for Animal Health (OIE) said in a joint statement today.
Recent outbreaks in China, Vietnam, Cambodia, Malaysia and Thailand show that the virus continues to circulate in the region and will not probably be eradicated in the near future, the two organizations said.
More research is urgently needed as the role of wildlife, domestic ducks and pigs in transmitting the virus among animals is still not fully understood. A permanent threat to animal and human health continues to exist.
Major investments needed
While much progress has been made in early detection and reaction, countries still need to step up proactive surveillance and control measures. Major investments are required to strengthen veterinary services, in particular for surveillance, early warning, detection, reporting and response and for the rehabilitation and restructuring of the poultry sector, FAO/OIE said.
The newly published FAO Recommendations on the Prevention, Control and Eradication of Highly Pathogenic Avian Influenza (HPAI) in Asia , prepared in close collaboration with OIE, review the factors that should be taken into account in designing and implementing control programmes and explain how countries can adopt a strategy appropriate to their individual situation.
In response to recent controversies on vaccination against bird flu, OIE and FAO reiterated that the slaughter of infected animals is the best way of controlling and ultimately stamping out the disease.
However, FAO/OIE acknowledged that this policy may not be practical or adequate in certain countries because of social and economic reasons or because of high viral challenge due to infection in villages, wild birds or domestic waterfowl. In such cases, countries wishing to eradicate the disease may choose to use vaccination as a complementary measure to the stamping out policy.
The two agencies stressed that vaccines, if used, should be produced in accordance with the international guidelines prescribed in the OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals .
The OIE Terrestrial Code states that a country may be considered free from HPAI based on the absence of virus irrespective of whether vaccination has been carried out. Therefore, the two organisations confirm that the use of vaccines does not imply automatic loss of export markets.
It has been shown that the use of such vaccines does not only protect healthy birds from disease but also reduces the load of viruses excreted by infected birds and thus the likelihood of transmission of the virus to other birds and to humans.
However, the decision on whether to use vaccines has to be made by each country based on its own situation, OIE/FAO said.
The factors countries should consider in making their decision include their ability to detect and react to the disease as early as possible and the need for transparent and timely notification; this will have to be supported by a good institutional framework and sound legislation underpinning veterinary services.
Any vaccination strategy should be developed in consultation with all stakeholders, including the private sector. The types of poultry and production sectors to be vaccinated must be determined and clearly documented. Infected poultry and those in contact with the virus should not be vaccinated.
The two agencies said vaccination should be carried out under the supervision of official veterinary services and be accompanied by a parallel surveillance strategy. This would include the capacity of the veterinary services to identify and monitor the circulating virus as well as the response to vaccination, by means including the use of non-vaccinated sentinel birds and the application of serological tests capable of differentiating infected from vaccinated animals.