tetano
Editor, Senior Moderator
J Virol. 2015 Aug 26. pii: JVI.01573-15. [Epub ahead of print]
[h=1]Evolutionary dynamics and global diversity of influenza A virus.[/h] Rejmanek D[SUP]1[/SUP], Hosseini PR[SUP]2[/SUP], Mazet JA[SUP]1[/SUP], Daszak P[SUP]2[/SUP], Goldstein T[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] The increasing number of zoonotic infections caused by influenza A virus (IAV) subtypes of avian origin in recent years (e.g. H5N1 and H7N9) underscores the need to better understand the factors driving IAV evolution and diversity. To evaluate the current feasibility of global analyses to contribute to this aim, we evaluated information in the public domain to explore IAV evolutionary dynamics including, nucleotide substitution rates and selection pressures, using 14 IAV subtypes in 32 different countries over a 12-year period (2000 - 2011). Using geospatial information from 39,785 IAV strains, we examined associations between subtype diversity and socio-economic, biodiversity, and agricultural indices. Our analyses showed that nucleotide substitution rates for 11 of the 14 evaluated subtypes tended to be higher in Asian countries, particularly those in East Asia, compared to Canada and the United States. Similarly at a regional level, subtypes H5N1, H5N2, and H6N2 exhibited significantly higher substitution rates in East Asia compared to North America. In contrast, the selection pressures (measured as d[SUB]N[/SUB]/d[SUB]S[/SUB] ratios) acting on individual subtypes showed little geographic variation. We found that the strongest predictors for the detected subtype diversity at the country level were reporting effort and healthcare spending (an indicator of economic development). Our analyses also identified major global gaps in IAV reporting (including lack of sequences submitted from large portions of Africa and South America, and lack of geolocation information) and broad subtype testing which, until addressed, will continue to hinder efforts to track the evolution and diversity of IAV around the world.
[h=4]IMPORTANCE:[/h] In recent years, an increasing number of influenza A virus (IAV) subtypes including H5N1, H7N9, and H10N8 have been detected in humans. Their high fatality rates have led to an increased urgency to better understand where and how novel pathogenic influenza strains emerge. Our findings showed that mutational rates of 11 commonly encountered subtypes were higher in East Asian countries compared to those in North America, suggesting there may be a greater risk for the emergence of novel pathogenic strains in East Asia. In assessing the potential drivers of IAV subtype diversity, our analyses confirmed that reporting effort and healthcare spending were the best predictors of observed subtype diversity at the country level. These findings underscore the need to increase sampling and reporting efforts for all subtypes in many under-sampled countries throughout the world.
Copyright ? 2015, American Society for Microbiology. All Rights Reserved.
PMID: 26311890 [PubMed - as supplied by publisher]
[h=1]Evolutionary dynamics and global diversity of influenza A virus.[/h] Rejmanek D[SUP]1[/SUP], Hosseini PR[SUP]2[/SUP], Mazet JA[SUP]1[/SUP], Daszak P[SUP]2[/SUP], Goldstein T[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] The increasing number of zoonotic infections caused by influenza A virus (IAV) subtypes of avian origin in recent years (e.g. H5N1 and H7N9) underscores the need to better understand the factors driving IAV evolution and diversity. To evaluate the current feasibility of global analyses to contribute to this aim, we evaluated information in the public domain to explore IAV evolutionary dynamics including, nucleotide substitution rates and selection pressures, using 14 IAV subtypes in 32 different countries over a 12-year period (2000 - 2011). Using geospatial information from 39,785 IAV strains, we examined associations between subtype diversity and socio-economic, biodiversity, and agricultural indices. Our analyses showed that nucleotide substitution rates for 11 of the 14 evaluated subtypes tended to be higher in Asian countries, particularly those in East Asia, compared to Canada and the United States. Similarly at a regional level, subtypes H5N1, H5N2, and H6N2 exhibited significantly higher substitution rates in East Asia compared to North America. In contrast, the selection pressures (measured as d[SUB]N[/SUB]/d[SUB]S[/SUB] ratios) acting on individual subtypes showed little geographic variation. We found that the strongest predictors for the detected subtype diversity at the country level were reporting effort and healthcare spending (an indicator of economic development). Our analyses also identified major global gaps in IAV reporting (including lack of sequences submitted from large portions of Africa and South America, and lack of geolocation information) and broad subtype testing which, until addressed, will continue to hinder efforts to track the evolution and diversity of IAV around the world.
[h=4]IMPORTANCE:[/h] In recent years, an increasing number of influenza A virus (IAV) subtypes including H5N1, H7N9, and H10N8 have been detected in humans. Their high fatality rates have led to an increased urgency to better understand where and how novel pathogenic influenza strains emerge. Our findings showed that mutational rates of 11 commonly encountered subtypes were higher in East Asian countries compared to those in North America, suggesting there may be a greater risk for the emergence of novel pathogenic strains in East Asia. In assessing the potential drivers of IAV subtype diversity, our analyses confirmed that reporting effort and healthcare spending were the best predictors of observed subtype diversity at the country level. These findings underscore the need to increase sampling and reporting efforts for all subtypes in many under-sampled countries throughout the world.
Copyright ? 2015, American Society for Microbiology. All Rights Reserved.
PMID: 26311890 [PubMed - as supplied by publisher]