Scientific Discussion 1. Summary of the Dossier

Avian influenza occurs worldwide and not only affects domestic poultry, but also infects a wide range of feral birds covering 88 species and 22 families, occurring most prolifically in migratory waterfowl. Type A influenza virus can also infect various species of mammals (including humans). The main reservoir of infection is thought to be wild ducks, gulls and shorebirds. Infections in poultry can be unapparent, i.e. low pathogenic avian influenza (LPAI), or cause mild to severe respiratory disease, decreases in production, decreases in food or water intake, or cause a rapidly fatal systemic disease known as highly pathogenic avian influenza (HPAI). Important economic losses occur as a result of mortality, but also due to egg production loss, to retardation of growth, bad feed conversion, diminished quality and cost of medical treatment for secondary bacterial infections.