Propagation of Emerging and Re-Emerging Infectious Disease Pathogens in Africa: The Role of Migratory Birds

Migratory birds have been implicated in the spread of diverse emerging infectious pathogens, including West Nile virus, Usutu virus, Avian influenza viruses, Salmonella, Campylobacter, antimicrobial-resistant (AMR) bacteria, and antibiotic resistance genes (ARGs). Beyond their roles as vectors and reservoirs, migratory birds are also susceptible hosts whose own health may be compromised by these infections, reflecting their dual position in the ecology of pathogens. As facilitators of pathogen transmission during their long-distance migrations, often spanning thousands of kilometres and connecting ecosystems across continents, these birds can easily cross-national borders and circumvent traditional biosecurity measures, thereby acting as primary or secondary vectors in the transmission of cross-species diseases among wildlife, livestock, and humans. Africa occupies a pivotal position in global migratory bird networks, yet comprehensive data on pathogen carriage remain limited. Gaps in knowledge of pathogen diversity constrain current surveillance systems, resulting in insufficient genomic monitoring of pathogen evolution and a weak integration of avian ecology with veterinary and human health. These limitations hinder early detection of novel pathogens and reduce the continent’s preparedness to manage outbreaks. Therefore, this review provides a holistic assessment of these challenges by consolidating existing knowledge concerning the pathogens transmitted by migratory birds in Africa, while recognizing the adverse effect of pathogens, which potentiates population decline, extinction, and ecological imbalance. It further advocates for the adoption of a comprehensive One Health-omics approach that not only strengthens surveillance and technological capacity but also prioritizes the protection of avian health as an integral component of ecosystem and public health.