The role of Africa in the dynamics of the global spread of a zoonotic and economicallyimportant
virus, such as the highly pathogenic avian influenza (HPAI) H5Nx of the Gs/GD
lineage, remains unexplored. Here we characterise the spatiotemporal patterns of virus diffusion
during three HPAI H5Nx intercontinental epidemic waves and demonstrate that Africa
mainly acted as an ecological sink of the HPAI H5Nx viruses. A joint analysis of host
dynamics and continuous spatial diffusion indicates that poultry trade as well as wild bird
migrations have contributed to the virus spreading into Africa, with West Africa acting as a
crucial hotspot for virus introduction and dissemination into the continent. We demonstrate
varying paths of avian influenza incursions into Africa as well as virus spread within Africa
over time, which reveal that virus expansion is a complex phenomenon, shaped by an
intricate interplay between avian host ecology, virus characteristics and environmental
variables.
