A Global Review of Highly Pathogenic Avian Influenza (HPAI) and Control Strategies in Nepal

Highly pathogenic avian influenza (HPAI) is a transboundary and zoonotic viral disease affecting poultry and wild birds in many countries worldwide. Globally, HPAI outbreaks have led to the death or culling of hundreds of millions of birds over the past two decades and have caused nearly 1000 confirmed human H5N1 infections, with a case fatality rate of approximately 50%. Asia and Europe remain among the most affected regions, with recurrent outbreaks linked to intensive poultry production, live bird markets, and migratory bird pathways. In Nepal, HPAI has been reported since 2009, with more than 320 outbreaks recorded and over 2.7 million birds lost, alongside one confirmed human fatality. Control measures rely largely on stamping out, movement restrictions, and surveillance; however, gaps in farm-level biosecurity, informal cross-border poultry trade, and limited vaccination use continue to sustain vulnerability. Strengthened multisectoral coordination under a One Health framework, integrating veterinary and public health surveillance, molecular monitoring, community awareness, and risk-based biosecurity enforcement, is essential to reduce the impact of HPAI and mitigate future zoonotic and pandemic risks.