Background: High pathogenicity avian influenza (HPAI) viruses have rapidly emerged as a major global threat to wildlife, with severe consequences for seabird populations. Albatrosses and petrels (order Procellariiformes) are particularly vulnerable due to their long lifespan, low reproductive rates and strong site fidelity. Since 2021, HPAI viruses have caused unprecedented mortality in seabird communities worldwide and have expanded into the core range of procellariiform species, including sub-Antarctic and Antarctic regions.

New information: In response to the urgent need for timely, species-relevant information, the Agreement on the Conservation of Albatrosses and Petrels (ACAP) established the High Pathogenicity H5Nx Avian Influenza Intersessional Correspondence Group (HPAI-ICG), which developed the ACAP HPAI database - an openly accessible, regularly updated resource that consolidates all known suspected and confirmed HPAI events involving procellariiform birds. The database compiles information from global and national reporting systems, scientific literature, genetic repositories, government communications and direct expert notifications. Events are standardised using transparent case definitions, cross-referenced and validated by subject-matter experts and complemented by additional data on case impacts and viral characteristics. The database provides a critical decision-support tool for governments, researchers, conservation practitioners and tourism operators, contributing to the planning and implementation of HPAI biosafety, surveillance, monitoring and outbreak response activities.