Where is avian influenza usually found?
The virus originated in Eastern Asia, and has tended to spread westward; new strains appear periodically, some classified as low pathogenicity avian influenza (LPAI), causing little harm to infected birds. Other strains are high pathogenicity avian influenza (HPAI); causing serious illness and death among infected birds, and similarly in people. H5N1 is currently the HPAI causing major concern; first isolated in the east, it reached Scotland in April 2006.
