The global distribution and diversity of wild bird-associated pathogens: an integrated data analysis and modelling

This article is a preprint with The Lancet

Abstract

Background

Wild birds are recognized as important vectors for the transmission of various pathogens across regions and species. However, there is limited knowledge regarding the diversity and global distribution of wild bird-associated pathogens (WAPs).

Methods

We compiled an up-to-date dataset encompassing all WAPs by conducting an extensive search on PubMed, Web of Science, GenBank, MedRvix, and bioRvix for publication from 1959 to 2022. We mapped the diversity and global distribution of WAPs, and utilized three machine learning algorithms to predict geospatial hotspots where zoonotic WAPs and emerging WAPs were prevalent.

Findings

Based on these selected 1834 studies, a total of 760 pathogens associated with 1438 wild bird species were identified. Among them, 387 are classified as emerging pathogens and 226 are defined as zoonotic (including 43 viruses, 102 bacteria, 32 parasites, and 49 fungi). West Nile virus and influenza A viruses exhibit the widest range of infectivity across wild bird species among the zoonotic WAPs. Migratory birds exhibited higher pathogen richness (593 species), but a lower proportion of zoonotic pathogens (28·5%) compared to resident birds (303 species and 40·2%, all p<0·01). 

When comparing different ecological groups, waterfowl had the highest richness of zoonotic pathogens (136 species) followed by songbirds (79), shorebirds (61), raptors (59), landfowl (58), and climbing birds (52). The geospatial distribution of WAPs was significantly influenced by the habitat suitability index of wild birds and climatic factors. Projected hotspots for zoonotic WAPs and emerging WAPs were especially widespread in the tropical regions of South America, Central Africa, South and Southeast Asia, in addition to being widely distributed in eastern North America, western Europe and the eastern seaboard of Asia.

Interpretation

This information could provide guidance for prioritizing surveillance, control and prevention efforts concerning avian infectious and zoonotic diseases.

Funding

National Key Research and Development Program of China.