Tweet
Accepted manuscript posted online 17 August 2016, doi: 10.1128/JVI.01404-16 JVI.01404-16
Evidence for the introduction, reassortment and persistence of diverse influenza A viruses in Antarctica
ABSTRACT
Avian influenza virus (AIV) surveillance in Antarctica during 2013 revealed the prevalence of evolutionarily distinct influenza viruses of H11N2 subtype in Ad?lie penguins. Here we present results from the continued surveillance of AIV on the Antarctic Peninsula during 2014 and 2015. In addition to the continued detection of H11 subtype viruses during 2014 in a snowy sheathbill, we isolated a novel H5N5 subtype virus during 2015 in a chinstrap penguin. Gene sequencing and phylogenetic analysis revealed that the H11 virus detected in 2014 had a >99.1% nucleotide similarity to the H11N2 viruses isolated in 2013, suggesting continued prevalence of this virus over multiple years in Antarctica. However, phylogenetic analysis of the H5N5 virus showed that their genome segments were recently introduced into the continent, except for the NP gene that was similar to that in the endemic H11N2 viruses. Our analysis indicates geographically diverse origins for the H5N5 virus genes; with the majority of its genome segments derived from North American lineage viruses, but the neuraminidase gene derived from a Eurasian lineage virus. In summary, we show the persistence of AIV lineages over multiple years in Antarctica; recent introduction of gene segments from diverse regions; and reassortment between different AIV lineages in Antarctica, which together, significantly increases our understanding of AIV ecology in this fragile and pristine environment.
IMPORTANCE Analysis of avian influenza viruses (AIVs) detected in Antarctica reveals both the relatively recent introduction of an H5N5 AIV predominantly of North American-like origin, as well as the persistence of an evolutionarily divergent H11 AIV. These data demonstrate that the flow of viruses from North America may be more common than initially thought, and that once introduced, these AIVs have the potential to be maintained within Antarctica. The future introduction of AIVs from North America into the Antarctic Peninsula is of particular concern given that highly pathogenic H5Nx viruses have recently been circulating amongst wild birds in parts of Canada and the Unites States following the movement of these viruses from Eurasia via migratory birds. The introduction of a highly pathogenic influenza virus into penguin colonies within Antarctica might have devastating consequences.
Evidence for the introduction, reassortment and persistence of diverse influenza A viruses in Antarctica
- Aeron C. Hurt1,2⇑,
- Yvonne C. F. Su3,
- Malet Aban1,
- Heidi Peck1,
- Hilda Lau1,
- Chantal Baas1,
- Yi-Mo Deng1,
- Natalie Spirason1,
- Patrik Ellstr?m4,
- Jorge Hernandez4,5,
- Bjorn Olsen6,
- Ian G. Barr1,
- Dhanasekaran Vijaykrishna3 and
- Daniel Gonzalez-Acuna7
- 1WHO Collaborating Centre for Reference and Research on Influenza, North Melbourne, Victoria 3051, Australia.
- 2University of Melbourne, Melbourne School of Population and Global Health, Parkville, Victoria 3010, Australia.
- 3Program in Emerging Infectious Diseases, Duke-NUS Medical School, 8 College Road, Singapore 169857
- 4Zoonosis Science Center, IMBIM, Uppsala University, Uppsala, Sweden
- 5Department of Microbiology, Kalmar County Hospital, Kalmar, Sweden
- 6Medical Sciences, Uppsala University, Uppsala, Sweden.
- 7Universidad de Concepci?n, Facultad de Ciencias Veterinarias, Chill?n, Chile.
ABSTRACT
Avian influenza virus (AIV) surveillance in Antarctica during 2013 revealed the prevalence of evolutionarily distinct influenza viruses of H11N2 subtype in Ad?lie penguins. Here we present results from the continued surveillance of AIV on the Antarctic Peninsula during 2014 and 2015. In addition to the continued detection of H11 subtype viruses during 2014 in a snowy sheathbill, we isolated a novel H5N5 subtype virus during 2015 in a chinstrap penguin. Gene sequencing and phylogenetic analysis revealed that the H11 virus detected in 2014 had a >99.1% nucleotide similarity to the H11N2 viruses isolated in 2013, suggesting continued prevalence of this virus over multiple years in Antarctica. However, phylogenetic analysis of the H5N5 virus showed that their genome segments were recently introduced into the continent, except for the NP gene that was similar to that in the endemic H11N2 viruses. Our analysis indicates geographically diverse origins for the H5N5 virus genes; with the majority of its genome segments derived from North American lineage viruses, but the neuraminidase gene derived from a Eurasian lineage virus. In summary, we show the persistence of AIV lineages over multiple years in Antarctica; recent introduction of gene segments from diverse regions; and reassortment between different AIV lineages in Antarctica, which together, significantly increases our understanding of AIV ecology in this fragile and pristine environment.
IMPORTANCE Analysis of avian influenza viruses (AIVs) detected in Antarctica reveals both the relatively recent introduction of an H5N5 AIV predominantly of North American-like origin, as well as the persistence of an evolutionarily divergent H11 AIV. These data demonstrate that the flow of viruses from North America may be more common than initially thought, and that once introduced, these AIVs have the potential to be maintained within Antarctica. The future introduction of AIVs from North America into the Antarctic Peninsula is of particular concern given that highly pathogenic H5Nx viruses have recently been circulating amongst wild birds in parts of Canada and the Unites States following the movement of these viruses from Eurasia via migratory birds. The introduction of a highly pathogenic influenza virus into penguin colonies within Antarctica might have devastating consequences.
