Avian influenza situation report-Africa

Abstract

Africa's vast geographic and climatic diversity makes it a critical region for the ecology and spread of avian influenza viruses, particularly due to its role as a wintering ground for Palearctic migratory waterbirds. The continent has experienced multiple waves of clade 2.3.4.4b A/H5Nx high pathogenicity avian influenza (HPAI), which has caused widespread outbreaks in poultry and wild birds since 2017. From 2023 to mid-2025, clade 2.3.4.4b A/H5N1 outbreaks were reported across West and Southern Africa, with severe impacts on poultry production and conservation of endangered wild bird species. Concurrently, South Africa and Mozambique battled an unprecedented A/H7N6 HPAI epizootic in 2023, leading to the culling or loss of over 6.8 million chickens. Additionally, the A/H9N2 subtype, particularly G5.5 sublineage strains, continues to circulate in North, West, and East Africa, with reassortant viruses with A/H5Nx viruses reported in Egypt. Underreporting and limited surveillance hamper accurate epidemiological assessment. Despite these challenges, advancements in noninvasive environmental sampling offer promising tools for early detection. Strengthening regional cooperation and surveillance is essential for mitigating future outbreaks and protecting both animal and public health.

Keywords: A/H7N6; A/H9N2; Africa; clade 2.3.4.4b A/H5Nx high pathogenicity avian influenza.