| 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 ... | 1982 | 6815876 |
| influenza a viruses isolated from waterfowl in two wildlife management areas of pennsylvania. | a survey was conducted at two wildlife management areas of pennsylvania (usa) to evaluate an antigen capture enzyme-linked immunosorbent assay (ac-elisa) for the detection of avian influenza viruses (aiv) in cloacal swabs from waterfowl and to determine the influenza a virus subtypes and the distribution of these viruses among waterfowl. we collected 330 cloacal swabs from hunter-killed waterfowl in the fall of 1990 and from cage-captured waterfowl in the summer of 1991. thirty-one hemagglutinat ... | 1995 | 8583635 |
| outbreaks of avian influenza h6n2 viruses in chickens arose by a reassortment of h6n8 and h9n2 ostrich viruses. | the first recorded outbreak of avian influenza (ai) in south african chickens (low pathogenicity h6n2) occurred at camperdown, kwazulu/natal province (kzn) in june 2002. to determine the source of the outbreak, we defined the phylogenetic relationships between various h6n2 isolates, and the previously unpublished gene sequences of an h6n8 virus isolated in 1998 from ostriches in the leeu gamka region (a/ostrich/south africa/kk98/98). we demonstrated that two distinct genetic h6n2 lineages (sub-l ... | 2007 | 16927114 |
| genome characterisation of the newly discovered avian influenza a h5n7 virus subtype combination. | in denmark, in 2003, a previously unknown subtype combination of avian influenza a virus, h5n7 (a/mallard/denmark/64650/03), was isolated from a flock of 12,000 mallards. the h5n7 subtype combination might be a reassortant between recent european avian influenza a h5, h7, and a third subtype, possibly an h6. the haemagglutinin and the acidic polymerase genes of the virus were closely related to a low-pathogenic danish h5n2 virus a/duck/denmark/65041/04 (h5n2). the neuraminidase gene and the non- ... | 2007 | 17115305 |
| hampered foraging and migratory performance in swans infected with low-pathogenic avian influenza a virus. | it is increasingly acknowledged that migratory birds, notably waterfowl, play a critical role in the maintenance and spread of influenza a viruses. in order to elucidate the epidemiology of influenza a viruses in their natural hosts, a better understanding of the pathological effects in these hosts is required. here we report on the feeding and migratory performance of wild migratory bewick's swans (cygnus columbianus bewickii yarrell) naturally infected with low-pathogenic avian influenza (lpai ... | 2007 | 17264886 |
| phylogenetic analysis of low-pathogenicity avian influenza h6n2 viruses from chicken outbreaks (2001-2005) suggest that they are reassortants of historic ostrich low-pathogenicity avian influenza h9n2 and h6n8 viruses. | low-pathogenicity (lpai) and high-pathogenicity (hpai) avian influenza viruses are periodically isolated from south african ostriches, but during 2002 the first recorded outbreak of lpai (h6n2) in south african chickens occurred on commercial farms in the camperdown area of kwazulu/natal (kzn) province. sequence analysis of all eight genes were performed and phylogenetic analysis was done based on the hemagglutinin and neuraminidasc sequences. results from phylogenetic analyses indicated that th ... | 2007 | 17494567 |
| virologic findings in selected free-range mule duck farms at high risk for avian influenza infection. | prevalence of avian influenza infection in free-range mule ducks (a cross between muscovy [cairina moschata domesticus] and pekin ducks [anas platyrhychos domesticus]) is a matter of concern and deserves particular attention. thus, cloacal swabs were collected blindly from 30 targeted mule flocks at 4, 8, and 12 wk of age between october 2004 and january 2005. they were stored until selection. on the basis of a positive h5 antibody detection at 12 wk of age with the use of four h5 antigens, the ... | 2007 | 17494595 |
| 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 ... | 2007 | 17494599 |
| origin of the 1918 spanish influenza virus: a comparative genomic analysis. | to test the avian-origin hypothesis of the 1918 spanish influenza virus we surveyed influenza sequences from a broad taxonomic distribution and collected 65 full-length genomes representing avian, human and "classic" swine h1n1 lineages in addition to numerous other swine (h1n2, h3n1, and h3n2), human (h2n2, h3n2, and h5n1), and avian (h1n1, h4n6, h5n1, h6n1, h6n6, h6n8, h7n3, h8n4, h9n2, and h13n2) subtypes. amino acids from all eight segments were concatenated, aligned, and used for phylogenet ... | 2008 | 18353690 |
| surveillance of avian influenza viruses in northern pintails (anas acuta) in tohoku district, japan. | among winter migratory waterfowl, northern pintails (anas acuta), in one of the largest flocks in tohoku district, northeast japan, were surveyed for influenza a viruses at five wintering sites in three prefectures, viz., aomori, akita, and miyagi. a total of 38 influenza a viruses were isolated from 2066 fecal samples collected during november 2006 through march 2007. the overall isolation rate was 1.84%. eleven different subtypes were isolated, including nine h5n2, seven h6n8, seven h10n1, fou ... | 2008 | 18459295 |
| [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. | 2008 | 19160806 |
| phylogenetic analysis of influenza a viruses (h6n8, h1n8, h4n2, h9n2, h10n7) isolated from wild birds, ducks, and ostriches in south africa from 2007 to 2009. | influenza a strains emerging from wild birds are a constant threat to south africa's valuable ostrich industry. in 2004 and again in 2006, low pathogenicity avian influenza h5n2 strains introduced from a wild bird reservoir mutated in ostriches to high pathogenicity avian influenza (hpai), with serious economic consequences and export bans imposed by the european union. although no outbreaks of notifiable avian influenza have occurred in south africa since 2006, the h9n2 virus caused a localized ... | 2010 | 20521652 |
| long-term study on tenacity of avian influenza viruses in water (distilled water, normal saline, and surface water) at different temperatures. | the tenacity of three low pathogenicity avian influenza viruses (aiv; subtypes h4n6, h5n1, and h6n8) was tested at five different temperatures (-10, 0, 10, 20, and 30 c) in distilled water, normal saline, and surface water obtained from lake constance. infectivity of aiv in the samples was quantified at regular intervals by end point titration on madin-darby canine kidney cells for a maximum period of 36 wk, and duplicate samples were tested each time. the results showed that the survival time o ... | 2010 | 20521721 |
| use of filter carrier technique to measure the persistence of avian influenza viruses in wet environmental conditions. | a germ carrier technique was adapted for the determination of the persistence of influenza viruses in moist environments. the technique was employed with 3 low pathogenic avian influenza viruses (h4n6, h5n1, and h6n8), one human influenza virus (h1n1), and two model viruses (ndv and ecbo) in lake water at five different temperatures (30, 20, 10, 0, and -10°c). viral quantitation was carried out at regular intervals on cell culture for a maximum duration of 16 weeks. serial data were analyzed by ... | 2010 | 20833205 |
| surveillance of avian influenza virus in migratory water birds in eastern hokkaido, japan. | the epidemiological information has obtained on avian influenza virus (aiv) in eastern hokkaido, japan, where aiv surveillance has not been performed. cloacal or fecal samples obtained from migratory water birds were screened for aiv both by real-time reverse transcriptase polymerase chain reaction to detect the influenza a virus matrix (m) gene and by egg inoculation. between 2007 and 2009, a total of 2,488 samples were collected from various avian species in abashiri, kushiro, nemuro and tokac ... | 2010 | 20948168 |
| persistence of avian influenza viruses in lake sediment, duck feces, and duck meat. | the persistence of 3 low pathogenicity avian influenza (lpai) viruses (h4n6, h5n1, and h6n8), one human influenza virus (h1n1) as well as ndv and ecbo was investigated in lake sediment, duck feces, and duck meat at 30, 20, 10, and 0 °c using a germ carrier technique. virus loaded germ carriers were incubated in each substrate and residual infectivity of the eluted virus was quantified on cell culture after regular intervals for a maximum of 24 weeks. data was analyzed by linear regression model ... | 2011 | 21622783 |
| non-structural protein 1 of avian influenza a viruses differentially inhibit nf-kappab promoter activation. | abstract: background: influenza virus infection activates nf-kappab and is a general prerequisite for a productive influenza virus infection. on the other hand, non-structural protein 1 (ns1) suppresses this viral activated nf-kappab, presumably to prevent expression of nf-kappab mediated anti-viral response. ns1 proteins of influenza a viruses are divided into two groups, known as allele a and allele b. the possible functional relevance of this ns1 division to viral pathogenicity is lacking. fi ... | 2011 | 21810221 |
| 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. | 2011 | 21999472 |
| is there a relation between genetic or social groups of mallard ducks and the circulation of low pathogenic avian influenza viruses? | we investigated the circulation dynamics of low pathogenic avian influenza viruses (lpaivs) in the mallard (anas platyrhynchos) reservoir in italy. in particular, we evaluated the temporal distribution of virologic findings by combining virus isolation data with a new population genetic-based study approach. thus, during 11 consecutive sampling periods (wintering periods between 1993/94 and 2003/04), categorised into 40 sampling sub-periods, cloacal swab samples were collected from 996 wild and ... | 2014 | 24690373 |
| molecular and epidemiological characterization of avian influenza viruses from gulls and dabbling ducks in norway. | wild aquatic birds constitute the natural reservoir for avian influenza viruses (aivs). separate eurasian and american aiv gene pools exist. here, the prevalence and diversity of aivs in gulls and dabbling ducks in norway were described. the influence of host species and temporal changes on aiv prevalence was examined. five aivs from norway, including three from common gull (larus canus), were analyzed along with 10 available aiv genomes from gulls in eurasia to search for evidence of intraconti ... | 2013 | 23575317 |
| immunization with baculovirus displayed h6 hemagglutinin vaccine protects mice against lethal h6 influenza virus challenge. | low pathogenic influenza viruses of h6 hemagglutinin (ha) subtype have a high prevalence among aquatic and domestic birds and have caused outbreaks in poultry worldwide. the first human infection with wild avian influenza h6n1 virus was reported in taiwan and these subtype viruses may continue to evolve and accumulate changes which increasing the potential risk of human-to-human transmission. to develop a vaccine against influenza viruses of the h6 subtype, we displayed the ha gene on the baculo ... | 2014 | 24973759 |
| consecutive natural influenza a virus infections in sentinel mallards in the evident absence of subtype-specific hemagglutination inhibiting antibodies. | dabbling ducks, particularly mallards (anas platyrhynchos) have been frequently and consistently reported to play a pivotal role as a reservoir of low pathogenic avian influenza viruses (aiv). from october 2006 to november 2008, hand-raised mallard ducks kept at a pond in an avifaunistically rich area of southern germany served as sentinel birds in the aiv surveillance programme in germany. the pond was regularly visited by several species of dabbling ducks. a flock of sentinel birds, consisting ... | 2013 | 22816511 |
| epidemiological surveillance of low pathogenic avian influenza virus (lpaiv) from poultry in guangxi province, southern china. | low pathogenic avian influenza virus (lpaiv) usually causes mild disease or asymptomatic infection in poultry. however, some lpaiv strains can be transmitted to humans and cause severe infection. genetic rearrangement and recombination of even low pathogenic influenza may generate a novel virus with increased virulence, posing a substantial risk to public health. southern china is regarded as the world "influenza epicenter", due to a rash of outbreaks of influenza in recent years. in this study, ... | 2013 | 24204754 |
| complete genome sequence of a novel reassortant h6n8 avian influenza virus isolated from wild waterfowl in poyang lake, china. | here, we report the complete genome sequence of an h6n8 avian influenza virus (aiv) isolated from wild waterfowl in poyang lake, china, in 2016. phylogenetic analysis showed that it was a novel reassortant aiv between domestic ducks and wild waterfowl. the finding of this study is helpful for our understanding of the ecology and the evolutionary characteristics of h6 subtypes of aiv in birds. | 2017 | 28153897 |
| a comparison of virulence of influenza a virus isolates from mallards in experimentally inoculated turkeys. | low pathogenic avian influenza viruses (lpaiv) from wild waterfowl can and do cross species barriers, infecting and sometimes becoming established in domestic poultry. turkeys are naturally highly susceptible to lpaiv infections, especially with viruses from ducks. in this study, we describe clinical signs and lesions in experimentally inoculated commercial turkeys produced by a lpaiv, a/mallard/mn/1714/09 (h7n1), isolated from a mallard duck. our results demonstrate that this h7n1 isolate produ ... | 2013 | 24597123 |
| freshwater clams as bioconcentrators of avian influenza virus in water. | we report experimental evidence for bioconcentration of a low-pathogenicity avian influenza virus (h6n8) in the tissue of freshwater clams. our results support the concept that freshwater clams may provide an effective tool for use in the early detection of influenza a viruses in aquatic environments. | 2012 | 22925022 |
| replication and adaptive mutations of low pathogenic avian influenza viruses in tracheal organ cultures of different avian species. | transmission of avian influenza viruses (aiv) between different avian species may require genome mutations that allow efficient virus replication in a new species and could increase virulence. to study the role of domestic poultry in the evolution of aiv we compared replication of low pathogenic (lp) aiv of subtypes h9n2, h7n7 and h6n8 in tracheal organ cultures (toc) and primary embryo fibroblast cultures of chicken, turkey, pekin duck and homing pigeon. virus strain-dependent and avian species ... | 2012 | 22912693 |
| antibody response and viral shedding profile of egyptian geese (alopochen aegyptiacus) infected with low pathogenicity h7n1 and h6n8 avian influenza viruses. | egyptian geese (alopochen aegypticus), a duck species endemic to sub-saharan africa and occasionally implicated in the transmission of avian influenza viruses (aiv) to farmed ostriches, were experimentally infected with low pathogenicity h7n1 and h6n8 viruses to assess viral shedding and immune profiles. following the first infection with h7n1 virus, high titers of virus were shed from both the tracheae and cloacae for at least 7 days postinfection, and tracheal shedding lasting until day 14. al ... | 2012 | 22856191 |