using rrt-pcr analysis and virus isolation to determine the prevalence of avian influenza virus infections in ducks at minto flats state game refuge, alaska, during august 2005.this study describes surveillance for avian influenza viruses (aiv) in the minto flats state game refuge, high-density waterfowl breeding grounds in alaska. five hundred paired cloacal samples from dabbling ducks (northern pintail, mallard, green wing teal, and widgeon) were placed into ethanol and viral transport medium (vtm). additional ethanol-preserved samples were taken. of the ethanol-preserved samples, 25.6% were aiv rna-positive by real-time rt-pcr. the hemagglutinin (ha) and neuraminida ...200717541700
influenza a viruses in wild birds of the pacific flyway, 2005-2008.avian influenza viruses (aivs) pose a significant threat to public health, and viral subtypes circulating in natural avian reservoirs can contribute to the emergence of pathogenic influenza viruses in humans. we investigated the prevalence and distribution of aivs in 8826 migratory and resident wild birds in north america along the pacific flyway, which is a major north-south migration pathway that overlaps with four other flyways in alaska providing opportunities for mixing of eurasian and amer ...201020059316
intercontinental reassortment and genomic variation of low pathogenic avian influenza viruses isolated from northern pintails (anas acuta) in alaska: examining the evidence through space and time.migration and population genetic data for northern pintails (anas acuta) and phylogenetic analysis of low pathogenic avian influenza (lpai) viruses from this host in alaska suggest that northern pintails are involved in ongoing intercontinental transmission of avian influenza. here, we further refine this conclusion through phylogenetic analyses which demonstrate that detection of foreign lineage gene segments is spatially dependent and consistent through time. our results show detection of fore ...201020227102
mx gene diversity and influenza association among five wild dabbling duck species (anas spp.) in (myxovirus-resistant) proteins are induced by interferon and inhibit viral replication as part of the innate immune response to viral infection in many vertebrates. influenza a virus appears to be especially susceptible to mx antiviral effects. we characterized exon 13 and the 3' utr of the mx gene in wild ducks, the natural reservoir of influenza virus and explored its potential relevance to influenza infection. we observed a wide range of intra- and interspecies variations. total nucleotide ...201020621205
interspecific exchange of avian influenza virus genes in alaska: the influence of trans-hemispheric migratory tendency and breeding ground sympatry.the movement and transmission of avian influenza viral strains via wild migratory birds may vary by host species as a result of migratory tendency and sympatry with other infected individuals. to examine the roles of host migratory tendency and species sympatry on the movement of eurasian low-pathogenic avian influenza (lpai) genes into north america, we characterized migratory patterns and lpai viral genomic variation in mallards (anas platyrhynchos) of alaska in comparison with lpai diversity ...201021073586
evidence for limited exchange of avian influenza viruses between seaducks and dabbling ducks at alaska peninsula coastal lagoons.avian influenza virus (aiv) prevalence and sequence data were analyzed for steller's eiders (polysticta stelleri) to assess the role of this species in transporting virus genes between continents and maintaining a regional viral reservoir with sympatric northern pintails (anas acuta). aiv prevalence was 0.2% at izembek lagoon and 3.9% at nelson lagoon for steller's eiders and 11.2% for northern pintails at izembek lagoon. phylogenetic analysis of 13 aivs from steller's eiders revealed that 4.9% ...201121766196
cross-seasonal patterns of avian influenza virus in breeding and wintering migratory birds: a flyway perspective.abstract the spread of avian influenza viruses (aiv) in nature is intrinsically linked with the movements of wild birds. wild birds are the reservoirs for the virus and their migration may facilitate the circulation of aiv between breeding and wintering areas. this cycle of dispersal has become widely accepted; however, there are few aiv studies that present cross-seasonal information. a flyway perspective is critical for understanding how wild birds contribute to the persistence of aiv over l ...201121995264
interspecies transmission and limited persistence of low pathogenic avian influenza genomes among alaska dabbling ducks.the reassortment and geographic distribution of low pathogenic avian influenza (lpai) virus genes are well documented, but little is known about the persistence of intact lpai genomes among species and locations. to examine persistence of entire lpai genome constellations in alaska, we calculated the genetic identities among 161 full-genome lpai viruses isolated across 4 years from five species of duck: northern pintail (anas acuta), mallard (anas platyrhynchos), american green-winged teal (anas ...201121964597
genetic structure of pacific flyway avian influenza viruses is shaped by geographic location, host species, and sampling period.the eight gene segments of avian influenza virus (aiv) reassort frequently and rapidly to generate novel genotypes and subtypes that are transmissible to a broad range of hosts. there is evidence that aiv can have a restricted host range and can segregate in space and time. host-virus relationships at the species, geographic, and spatial scales have not been fully defined for aiv populations of the pacific flyway, particularly among the diverse waterfowl that occupy the flyway in alaska and cali ...201222222690
Displaying items 1 - 9 of 9