South-East and East Asian countries have been severely affected by Highly Pathogenic Avian Influenza (HPAI).
This follows the emergence of a new virulent strain of virus in southern China in 1996 and its subsequent spread throughout the region since 2003. From past experience, it is understood that intimate contact between livestock (poultry and swine) and people in parts of Asia creates a favourable situation for the evolution of a human pandemic strain.
The current strain of the virus (designated H5N1 by virtue of the characterisation of surface markers) has already demonstrated its ability to infect and kill people. It has been fatal in approximately 50 per cent of people who have tested positive for the disease. To date, there is limited evidence of person-to-person transmission. Swine and other affected mammals appear to be only incidentally infected, playing no significant role in virus transmission. However, this situation could change rapidly and the emergence, by recombination or mutation, of a highly pathogenic strain of Influenza which could transmit rapidly between people and cause a global pandemic is a matter of international concern. The most effective means of protecting human welfare is to combat the precursor virus in its Avian hosts, thus pre-empting the appearance of a pandemic strain.