There is growing evidence that the avian influenza which has been responsible for serious disease outbreaks in poultry and humans in several Asian countries since 2003 was spread through a number of sources, including poor biosecurity at poultry farms, movement of poultry and poultry products and live market trade, illegal and legal trade in wild birds.

Although unproven, it is also suspected that the virus could possibly be carried over long distances along the migratory bird flyways to regions previously unaffected, which is a cause of serious concern for the region. It is suspected that Avian influenza subtype H5N1 could be transported along these routes to densely populated areas on the rest of the continent of Asia and to the Middle East, Africa and Europe. Indeed through any of these modes HPAI outbreaks have occurred in eight countries in Africa since the beginning of 2006, causing the loss of at least 30 million domestic poultry through deaths or culling.