isolation of influenza a viruses from birds in great britain during 1980 and 1981.during 1980 and 1981 influenza a viruses of subtypes h3n2, h3n8, h4n1, h4n6, h6n2, h6n8, h7n7, h11n8 and h11n9 were isolated from birds in great britain, usually as a result of investigations of disease or death. however, all viruses were shown to be of low virulence for chickens in pathogenicity index tests. there was one occurrence of influenza virus infection of turkeys (h6n8) but viruses were frequently obtained from domestic ducks. other viruses were isolated from exotic birds in zoos or bi ...19826815876
multiple avian influenza infection: selection of a non-avid virus by a heterologous avian host.experimental infection of domestic fowl, ducks and geese with an influenza a virus (h7n2) isolated from a domestic duck showed that this virus was apathogenic for these poultry. a second virus (h6n2), also apathogenic and more 'non-avid' than any such isolates previously recognised in surveillance of domestic poultry in hong kong, was isolated from one goose after h7n2 shedding had ceased. this goose, in effect, acted as a selective isolation system for the h6n2 virus whose presence in the field ...19827134641
molecular epizootiology of recurrent low pathogenic avian influenza by h9n2 subtype virus in korea.the first outbreak of low pathogenic avian influenza (lpai), h9n2 virus subtype, in 1996 prompted an eradication response, but lpai returned to korea in 1999. the relationship between the first and the recurrent viruses is unclear. to determine the molecular epizootiology of recurrent lpai, we performed phylogenetic analysis with partial nucleotide sequences of four gene segments (ha, na, np and pb2) from eight chicken-origin h9n2 viruses. the recurrent h9n2 viruses showed higher nucleotide simi ...200616854644
avian influenza virus screening in wild waterfowl in norway, 2005.the prevalence of influenza a virus infection, and the distribution of different subtypes of the virus, were studied in 604 geese and ducks shot during ordinary hunting 2005. the study was based upon molecular screening of cloacal swabs taken by the hunters. the sampling included the following species: greylag (anser anser), mallard (anas platyrhynchos), wigeon (anas penelope), teal (anas crecca), goosander (mergus merganser), tufted duck (aythya fuligula), common scoter (melanitta nigra), golde ...200717494599
evaluation of a positive marker of avian influenza vaccination in ducks for use in h5n1 surveillance.control measures for h5n1 avian influenza involve increased biosecurity, monitoring, surveillance and vaccination. subclinical infection in farmed ducks is important for virus persistence. in major duck rearing countries, homologous h5n1 vaccines are being used in ducks, so sero-surveillance using h5- or n1-specific antibody testing cannot identify infected flocks. an alternative is to include a positive marker for vaccination. testing for an antibody response to the marker would confirm approve ...200818723069
[distribution of avian influenza virus subtypes among domestic ducks in eastern china].to identify the distribution of avian influenza virus subtypes among domestic ducks in eastern china.200819160806
genetic relatedness of h6 subtype avian influenza viruses isolated from wild birds and domestic ducks in korea and their pathogenicity in animals.we report the genetic characterization of h6 avian influenza (ai) viruses isolated from domestic ducks and wild birds in korea between april 2008 and april 2009. a phylogenetic analysis showed that the h6n1 viruses of wild birds and domestic ducks were of the same genotype (k-1) and were similar to the h6n1 virus isolated from a live poultry market in 2003, as six of the eight gene segments of those viruses had a common source. however, the h6n2 viruses of domestic poultry were separated into fo ...201019812266
establishment of an h6n2 influenza virus lineage in domestic ducks in southern china.multiple reassortment events between different subtypes of endemic avian influenza viruses have increased the genomic diversity of influenza viruses circulating in poultry in southern china. gene exchange from the natural gene pool to poultry has contributed to this increase in genetic diversity. however, the role of domestic ducks as an interface between the natural gene pool and terrestrial poultry in the influenza virus ecosystem has not been fully characterized. here we phylogenetically and ...201020463062
molecular evolution of the h6 subtype influenza a viruses from poultry in eastern china from 2002 to 2010.although extensive data demonstrates that the majority of h6 duck isolates belonged to a single h6n2 virus lineage with a single gene constellation in southern china from 2000 to 2005, the prevalence of h6n2 virus in poultry in eastern china is largely unknown.201121999472
characterization of a low pathogenic avian influenza virus (h6n1) isolated from avian influenza virus (aiv), a/turkey/israel/09 subtype h6n1, was isolated from turkey poults exhibiting typical pathology associated with aiv infection. the virus was characterized by rt-pcr using aiv subtype-specific primers and by the haemagglutination inhibition test using aiv subtype-specific antisera. the virus has an intravenous pathogenicity index of 0 and possessed a nucleotide sequence at the cleavage site of the hemagglutinin gene, pqietr*glf, associated with avian influenza viruse ...201123074655
resistance mutation r292k is induced in influenza a(h6n2) virus by exposure of infected mallards to low levels of oseltamivir.resistance to neuraminidase inhibitors (nais) is problematic as these drugs constitute the major treatment option for severe influenza. extensive use of the nai oseltamivir (tamiflu®) results in up to 865 ng/l of its active metabolite oseltamivir carboxylate (oc) in river water. there one of the natural reservoirs of influenza a, dabbling ducks, can be exposed. we previously demonstrated that an influenza a(h1n1) virus in mallards (anas platyrhynchos) exposed to 1 µg/l of oc developed oseltamivi ...201323951116
competition between influenza a virus subtypes through heterosubtypic immunity modulates re-infection and antibody dynamics in the mallard duck.our overall hypothesis is that host population immunity directed at multiple antigens will influence the prevalence, diversity and evolution of influenza a virus (iav) in avian populations where the vast subtype diversity is maintained. to investigate how initial infection influences the outcome of later infections with homologous or heterologous iav subtypes and how viruses interact through host immune responses, we carried out experimental infections in mallard ducks (anas platyrhynchos). mall ...201728640898
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