Highly Pathogenic Avian Influenza (HPAI) virus of the H5N1 subtype re-emerged in Southeast Asia in late 2003 and can now be considered endemic in the region. Like other highly contagious livestock diseases, HPAI affects poultry production via three main pathways: (1) through the direct impact of disease-related morbidity and mortality, and the costs associated with ex-ante risk mitigation and / or ex-post coping measures that affect the incomes of producers and other stakeholders connected to poultry production and marketing; (2) through government interventions aimed at disease control, which include culling, marketing and movement restrictions, and investment in animal health infrastructure and disease preparedness; and (3) through consumer and market reactions, both domestic and international, affecting demand for poultry and poultry products and their substitutes, and thus prices of products and production inputs.