A 4-year study of avian influenza virus prevalence and subtype diversity in ducks of Newfoundland, Canada

2013 ◽  
Vol 59 (10) ◽  
pp. 701-708 ◽  
Author(s):  
Yanyan Huang ◽  
Michelle Wille ◽  
Ashley Dobbin ◽  
Gregory J. Robertson ◽  
Pierre Ryan ◽  
...  
Keyword(s):  
Influenza Virus ◽  
North America ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
North Atlantic Ocean ◽  
Migratory Bird ◽  
The North ◽  
Environmental Reservoir ◽  
American Black

The island of Newfoundland, Canada, is at the eastern edge of North America and has migratory bird connections with the continental mainland as well as across the North Atlantic Ocean. Here, we report a 4-year avian influenza virus (AIV) epidemiological study in ducks in the St. John’s region of Newfoundland. The overall prevalence of AIV detection in ducks during this study was 7.2%, with American Black Ducks contributing the vast majority of the collected samples and the AIV positives. The juvenile ducks showed a significantly higher AIV detection rate (10.6%) compared with adults (3.4%). Seasonally, AIV prevalence rates were higher in the autumn (8.4%), but positives were still detected in the winter (4.6%). Preliminary serology tests showed a high incidence of previous AIV infection (20/38, 52.6%). A total of 43 viruses were characterized for their HA–NA or HA subtypes, which revealed a large diversity of AIV subtypes and little recurrence of subtypes from year to year. Investigation of the movement patterns of ducks in this region showed that it is a largely non-migratory duck population, which may contribute to the observed pattern of high AIV subtype turnover. Phylogenetic analysis of 4 H1N1 and one H5N4 AIVs showed these viruses were highly similar to other low pathogenic AIV sequences from waterfowl in North America and assigned all gene segments into American-avian clades. Notably, the H1N1 viruses, which were identified in consecutive years, possessed homologous genomes. Such detection of homologous AIV genomes across years is rare, but indicates the role of the environmental reservoir in viral perpetuation.

scholarly journals Role of aflatoxin toxicity on transmissibility and pathogenicity of H9N2 avian influenza virus in turkeys

2015 ◽  
Vol 44 (4) ◽  
pp. 305-310 ◽  
Author(s):  
Sajid Umar ◽  
Muhammad Younus ◽  
Muti Ur Rehman ◽  
Asim Aslam ◽  
Muhammad Ali Abdullah Shah ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
H9n2 Avian Influenza Virus

scholarly journals The Impact of Migratory Flyways on the Spread of Avian Influenza Virus in North America

2016 ◽  
Author(s):  
Mathieu Fourment ◽  
Aaron E. Darling ◽  
Edward C. Holmes
Keyword(s):  
Influenza Virus ◽  
Genetic Structure ◽  
North America ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Bird Species ◽  
Influenza Viruses ◽  
Data Sets ◽  
Avian Influenza Viruses ◽  
The Impact

AbstractWild birds are the major reservoir hosts for influenza A viruses (AIVs) and have been implicated in the emergence of pandemic events in livestock and human populations. Understanding how AIVs spread within and across continents is therefore critical to the development of successful strategies to manage and reduce the impact of influenza outbreaks. In North America many bird species undergo seasonal migratory movements along a North-South axis, thereby fostering opportunities for viruses to spread over long distances. However, the role played by such avian flyways in shaping the genetic structure of AIV populations has proven controversial. To assess the relative contribution of bird migration along flyways to the genetic structure of AIV we performed a large-scale phylogeographic study of viruses sampled in the USA and Canada, involving the analysis of 3805 to 4505 sequences from 36 to 38 geographic localities depending on the gene data set. To assist this we developed a maximum likelihood-based genetic algorithm to explore a wide range of complex spatial models, thereby depicting a more complete picture of the migration network than previous studies. Based on phylogenies estimated from nucleotide data sets, our results show that AIV migration rates within flyways are significantly higher than those between flyways, indicating that the migratory patterns of birds play a key role in pathogen dispersal. These findings provide valuable insights into the evolution, maintenance and transmission of AIVs, in turn allowing the development of improved programs for surveillance and risk assessment.Significance StatementAvian influenza viruses infect a wide variety of wild bird species and represent a potential disease threat to the poultry industry and hence to human and livestock populations. However, the ecological factors that drive the geographic spread and evolution of these viruses are both poorly understood and controversial at the continental scale, particularly the role played by migratory flyways in shaping patterns of virus dispersal. Using a novel phylogeographic analysis of large genomic data sets we show migration flyways act as important transmission barriers to the spread of avian influenza viruses in North America. Hence, these results indicate that the spread of avian influenza virus in wild birds in North America has an element of predictability.

scholarly journals Detection of a Reassortant H9N2 Avian Influenza Virus with Intercontinental Gene Segments in a Resident Australian Chestnut Teal

Viruses ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 88 ◽  
Author(s):  
Tarka Raj Bhatta ◽  
Anthony Chamings ◽  
Jessy Vibin ◽  
Marcel Klaassen ◽  
Soren Alexandersen
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Phylogenetic Analyses ◽  
Gene Segment ◽  
Wild Birds ◽  
Influenza Viruses ◽  
H9n2 Avian Influenza Virus ◽  
The North ◽  
Southeastern Australia

The present study reports the genetic characterization of a low-pathogenicity H9N2 avian influenza virus, initially from a pool and subsequently from individual faecal samples collected from Chestnut teals (Anas castanea) in southeastern Australia. Phylogenetic analyses of six full gene segments and two partial gene segments obtained from next-generation sequencing showed that this avian influenza virus, A/Chestnut teal/Australia/CT08.18/12952/2018 (H9N2), was a typical, low-pathogenicity, Eurasian aquatic bird lineage H9N2 virus, albeit containing the North American lineage nucleoprotein (NP) gene segment detected previously in Australian wild birds. This is the first report of a H9N2 avian influenza virus in resident wild birds in Australia, and although not in itself a cause of concern, is a clear indication of spillover and likely reassortment of influenza viruses between migratory and resident birds, and an indication that any lineage could potentially be introduced in this way.

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