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Australia as a global sink for the genetic diversity of avian influenza A virus

Authors :
Michelle Wille
Victoria Grillo
Silvia Ban de Gouvea Pedroso
Graham W. Burgess
Allison Crawley
Celia Dickason
Philip M. Hansbro
Md. Ahasanul Hoque
Paul F. Horwood
Peter D. Kirkland
Nina Yu-Hsin Kung
Stacey E. Lynch
Sue Martin
Michaela McArthur
Kim O’Riley
Andrew J. Read
Simone Warner
Bethany J. Hoye
Simeon Lisovski
Trent Leen
Aeron C. Hurt
Jeff Butler
Ivano Broz
Kelly R. Davies
Patrick Mileto
Matthew J. Neave
Vicky Stevens
Andrew C. Breed
Tommy T. Y. Lam
Edward C. Holmes
Marcel Klaassen
Frank Y. K. Wong
Source :
PLoS Pathogens, Vol 18, Iss 5 (2022)
Publication Year :
2022
Publisher :
Public Library of Science (PLoS), 2022.

Abstract

Most of our understanding of the ecology and evolution of avian influenza A virus (AIV) in wild birds is derived from studies conducted in the northern hemisphere on waterfowl, with a substantial bias towards dabbling ducks. However, relevant environmental conditions and patterns of avian migration and reproduction are substantially different in the southern hemisphere. Through the sequencing and analysis of 333 unique AIV genomes collected from wild birds collected over 15 years we show that Australia is a global sink for AIV diversity and not integrally linked with the Eurasian gene pool. Rather, AIV are infrequently introduced to Australia, followed by decades of isolated circulation and eventual extinction. The number of co-circulating viral lineages varies per subtype. AIV haemagglutinin (HA) subtypes that are rarely identified at duck-centric study sites (H8-12) had more detected introductions and contemporary co-circulating lineages in Australia. Combined with a lack of duck migration beyond the Australian-Papuan region, these findings suggest introductions by long-distance migratory shorebirds. In addition, on the available data we found no evidence of directional or consistent patterns in virus movement across the Australian continent. This feature corresponds to patterns of bird movement, whereby waterfowl have nomadic and erratic rainfall-dependant distributions rather than consistent intra-continental migratory routes. Finally, we detected high levels of virus gene segment reassortment, with a high diversity of AIV genome constellations across years and locations. These data, in addition to those from other studies in Africa and South America, clearly show that patterns of AIV dynamics in the Southern Hemisphere are distinct from those in the temperate north. Author summary A result of the ever-growing poultry industry is a dramatic global increase in the incidence of high pathogenicity avian influenza virus outbreaks. In contrast, wild birds are believed to be the main reservoir for low pathogenic avian influenza A virus. Due to intensive research and surveillance of AIV in waterfowl in the Northern Hemisphere, we have a better understanding of AIV ecology and evolution in that region compared to the Southern Hemisphere, which are characterised by different patterns of avian migration and ecological conditions. We analysed 333 unique AIV genomes collected from wild birds in Australia to understand how Australia fits into global AIV dynamics and how viruses are maintained and dispersed within the continent of Australia. We show that the Southern Hemisphere experiences differing evolutionary dynamics to those seen in Northern Hemisphere with Australia representing a global sink for AIV.

Details

Language :
English
ISSN :
15537366 and 15537374
Volume :
18
Issue :
5
Database :
Directory of Open Access Journals
Journal :
PLoS Pathogens
Publication Type :
Academic Journal
Accession number :
edsdoj.597dd63c93ea48d69a56872424a6de66
Document Type :
article