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 ...201322816511
presence of avian influenza viruses in waterfowl and wetlands during summer 2010 in california: are resident birds a potential reservoir?although wild waterfowl are the main reservoir for low pathogenic avian influenza viruses (lpaiv), the environment plays a critical role for the circulation and persistence of aiv. lpaiv may persist for extended periods in cold environments, suggesting that waterfowl breeding areas in the northern hemisphere may be an important reservoir for aiv in contrast to the warmer southern wintering areas. we evaluated whether southern wetlands, with relatively small populations (thousands) of resident wa ...201222328934
a live-attenuated influenza vaccine for h3n2 canine influenza virus.canine influenza is a contagious respiratory disease in dogs caused by two subtypes (h3n2 and h3n8) of canine influenza virus (civ). currently, only inactivated influenza vaccines (iivs) are available for the prevention of civs. historically, live-attenuated influenza vaccines (laivs) have been shown to produce better immunogenicity and protection efficacy than iivs. here, we have engineered a civ h3n2 laiv by using the internal genes of a previously described civ h3n8 laiv as a master donor vir ...201728167384
canine h3n8 influenza vaccines partially protect mice against the canine h3n2 strain currently circulating in the united states.influenza a viruses infect many species and cross-species transmission occurs occasionally. an equine h3n8 influenza virus began circulating in dogs in 1999 and an avian h3n2 influenza virus began circulating in dogs in 2006. the canine h3n8 (ch3n8) viral strain has become endemic in parts of the united states and there is a commercially available vaccine against this strain. the canine h3n2 (ch3n2) strain did not circulate widely in the united states until 2015. here, we used a mouse model to d ...201627670073
seroepidemiological evidence of subtype h3n8 influenza virus infection among pet dogs in china.the h3n8 virus and the h3n2 virus are the main subtypes of canine influenza virus (civ). h3n8 civ mainly circulates in america, and h3n2 civ mainly circulates in asia. however, there was an outbreak of the asian h3n2 virus in the united states (us) in 2015. thus, it is important to evaluate the presence of subtype h3n8 virus in dogs in china. from may 2015 to november 2015, 600 sera from pet dogs were collected from guangzhou, shanghai, beijing and shenzhen for hemagglutination inhibition (hi) a ...201627414031
phylogenetic analysis and pathogenicity of h3 subtype avian influenza viruses isolated from live poultry markets in china.h3 subtype influenza a virus is one of the main subtypes that threats both public and animal health. however, the evolution and pathogenicity of h3 avian influenza virus (aiv) circulating in domestic birds in china remain largely unclear. in this study, seven h3 aivs (four h3n2 and three h3n8) were isolated from poultry in live poultry market (lpm) in china. phylogenetic analyses of full genomes showed that all viruses were clustered into eurasian lineage, except n8 genes of two h3n8 isolates fe ...201627270298
the avian-origin h3n2 canine influenza virus that recently emerged in the united states has limited replication in swine.equine-origin h3n8 has circulated in dogs in the united states since 1999. a genetically and antigenically distinct avian-origin h3n2 canine influenza was detected in march of 2015 in chicago, illinois. subsequent outbreaks were reported with over 1000 dogs in the midwest affected followed by 23 additional states with detections within 5 months. the potential for canine-to-swine transmission was unknown. experimental infection in pigs showed this virus does not replicate efficiently in swine.201627110913
new england harbor seal h3n8 influenza virus retains avian-like receptor influenza h3n8 virus, carrying mammalian adaptation mutations, was isolated from new england harbor seals in 2011. we sought to assess the risk of its human transmissibility using two complementary approaches. first, we tested the binding of recombinant hemagglutinin (ha) proteins of seal h3n8 and human-adapted h3n2 viruses to respiratory tissues of humans and ferrets. for human tissues, we observed strong tendency of the seal h3 to bind to lung alveoli, which was in direct contrast to the hu ...201626888262
cross-species infectivity of h3n8 influenza virus in an experimental infection in swine.avian influenza a viruses have gained increasing attention due to their ability to cross the species barrier and cause severe disease in humans and other mammal species as pigs. h3 and particularly h3n8 viruses, are highly adaptive since they are found in multiple avian and mammal hosts. h3n8 viruses have not been isolated yet from humans; however, a recent report showed that equine influenza a viruses (iavs) can be isolated from pigs, although an established infection has not been observed thus ...201526311894
serological evidence of equine influenza infections among persons with horse exposure, iowa.equine influenza virus (eiv) is considered enzootic in north america and experimental studies have documented human eiv infections.201525959164
serological survey for emerging canine h3n8 and h3n2 influenza viruses in pet and village dogs in nigeria, keeping of dogs as pets and guards is gaining popularity. to determine whether infection of dogs with novel canine influenza virus (civ) of equine (h3n8) and avian (h3n2) origins had occurred in nigeria, we screened pet and village dogs from lagos, ibadan, odeda and sagamu in southwestern nigeria for antibodies to civ h3n8 and h3n2.201426949788
safety and immunogenicity of a novel cold-adapted modified-live equine influenza virus design and evaluate the safety and immunogenicity of a modified-live vaccine to prevent equine influenza virus (eiv) infection based on the novel reassortant cold-adapted strain a/hk/otar/6:2/2010.201425348146
a population prevalence study on influenza infection in dogs in southern italy.despite several data on influenza infection in dogs, the first natural outbreak of canine influenza virus, closely related to h3n8 equine subtype, dates back to 2004 in florida. subsequent studies highlighted the role of dogs in adaptation of h5n1 to mammals and the susceptibility of dogs to different subtypes of influenza. a prevalence study was carried out on 562 sera collected from pet and kennel dogs in the south of italy. a c-elisa test was employed and c-elisa-positive, c-elisa-doubtful an ...201425180843
avian influenza virus h3 hemagglutinin may enable high fitness of novel human virus reassortants.reassortment of influenza a virus genes enables antigenic shift resulting in the emergence of pandemic viruses with novel hemagglutinins (ha) acquired from avian strains. here, we investigated whether historic and contemporary avian strains with different replication capacity in human cells can donate their hemagglutinin to a pandemic human virus. we performed double-infections with two avian h3 strains as ha donors and a human acceptor strain, and determined gene compositions and replication of ...201324265752
genetic characterization of h13 and h16 influenza a viruses in gulls (larus spp. ) with clinically severe disease and concurrent circovirus infection.influenza a viruses (iavs) of the subtypes h13 and h16 are primarily found in gulls ( larus spp., order charadriiformes). although the gull-adapted subtypes replicate efficiently during infection, gulls usually remain apparently healthy during infection. avian influenza virus isolates are generally separated into two distinct populations, north american and eurasian, because of the limited gene flow between the continents. reassortment between these lineages does occur occasionally; however, dir ...201728384060
genetic evolution of equine influenza virus strains (h3n8) isolated in france from 1967 to 2015 and the implications of several potential pathogenic factors.equine influenza virus (eiv) is a major respiratory pathogen of horses despite the availability of equine influenza vaccines. this study aimed to determine genetic evolution of eiv strains in france between 1967 to present. a whole genome comparative analysis was also conducted on recent french strains in order to identify potential factors of pathogenicity. comparison of french eiv sequences with vaccine and worldwide epidemic strains revealed amino acid substitutions in both haemagglutinin (ha ...201728292661
evolution and divergence of h3n8 equine influenza viruses circulating in the united kingdom from 2013 to 2015.equine influenza viruses (eiv) are a major cause of acute respiratory disease in horses worldwide and occasionally also affect vaccinated animals. like other influenza a viruses, they undergo antigenic drift, highlighting the importance of both surveillance and virus characterisation in order for vaccine strains to be kept up to date. the aim of the work reported here was to monitor the genetic and antigenic changes occurring in eiv circulating in the uk from 2013 to 2015 and to identify any evi ...201728208721
new influenza a(h7n7) viruses detected in live poultry markets in china.h7n7 avian influenza viruses have been widely detected in wild birds and domestic poultry since they were first detected in chickens in italy in 1902. they can occasionally transmit to humans. here, we isolated six h7n7 viruses in live poultry markets during routine surveillance from 2010 to 2013. sequences analysis revealed that these viruses are reassortants bearing genes of h3n8, h7n3, h7n7, and h10n7 influenza viruses detected in wild birds and ducks, and can be categorized into three genoty ...201627661735
canine influenza viruses with modified ns1 proteins for the development of live-attenuated vaccines.canine influenza virus (civ) h3n8 is the causative agent of canine influenza, a common and contagious respiratory disease of dogs. currently, only inactivated influenza vaccines (iivs) are available for the prevention of civ h3n8. however, live-attenuated influenza vaccines (laivs) are known to provide better immunogenicity and protection efficacy than iivs. influenza ns1 is a virulence factor that offers an attractive target for the preparation of attenuated viruses as laivs. here we generated ...201727750071
serological evidence of equine influenza virus in horse stables in kaduna, nigeria.equine influenza virus (eiv) is a major cause of acute respiratory diseases in horses in most parts of the world that results in severe economic losses. information on the epidemiology of eiv in tropical africa is scanty. an enzyme-linked immunosorbent assay (elisa) was used to detect the presence of influenza a virus nucleoprotein (np) in 284 horse sera in kaduna state, northern nigeria. the elisa-positive sera were further examined for hemagglutination inhibition (hi) antibodies to two strains ...201627703404
assessment of antigenic difference of equine influenza virus strains by challenge study in horses.we previously reported that horse antiserum against the japanese equine influenza vaccine virus, a/equine/la plata/1993 (lp93) exhibited reduced cross-neutralization against some florida sublineage clade (fc) 2 viruses, for example, a/equine/carlow/2011 (cl11). as a result, japanese vaccine manufacturers will replace lp93 with a/equine/yokohama/aq13/2010 (y10, fc2). to assess the benefit of updating the vaccine, five horses vaccinated with inactivated y10 vaccine and five vaccinated with inactiv ...201627465864
a review of evidence that equine influenza viruses are zoonotic.among scientists, there exist mixed opinions whether equine influenza viruses infect man. in this report, we summarize a 2016 systematic and comprehensive review of the english, chinese, and mongolian scientific literature regarding evidence for equine influenza virus infections in man. searches of pubmed, web of knowledge, proquest, cnki, chongqing vip database, wanfang data and mongolmed yielded 2831 articles, of which 16 met the inclusion criteria for this review. considering these 16 publica ...201627420100
a naturally truncated ns1 protein of influenza a virus impairs its interferon-antagonizing activity and thereby confers attenuation in vitro.the non-structural protein of influenza a virus (ns1a protein) is a multifunctional protein that antagonizes host antiviral responses and contributes to efficient viral replication during infection. however, most of its functions have been elucidated by generating recombinant viruses expressing mutated ns1 proteins that do not exist in nature. recently, the novel h3n8 a/equine/kyonggi/sa1/2011 (kg11) influenza virus was isolated in korea from horses showing respiratory disease symptoms. kg11 vir ...201727400993
comparing the functions of equine and canine influenza h3n8 virus pa-x proteins: suppression of reporter gene expression and modulation of global host gene expression.the influenza pa-x protein is translated from the pa open reading frame from frameshifting and suppresses cellular gene expression due to its ribonuclease activity. we further defined the functional roles of pa-x by comparing pa-x proteins from two related viruses - equine influenza (eiv) and canine influenza (civ) h3n8 - that differ in a c-terminal truncation and internal mutations. in vitro reporter gene assays revealed that both proteins were able to suppress gene expression. interestingly, e ...201627314620
influenza a virus infection in dogs: epizootiology, evolution and prevention - a review.canine influenza virus (civ) is an enveloped virus belonging to the genus influenza virus a within the family orthomyxoviridae. prior to 2004, only sporadic outbreaks of canine influenza had been observed in dog populations around the world. however, in 2004 an h3n8 influenza virus of equine origin caused severe respiratory disease in racing greyhounds in florida; subsequently, cases of dogs affected with various subtypes of civ have been reported in many countries. here, we performed a structur ...201626919150
the first reported florida clade 1 virus in the nordic countries, isolated from a swedish outbreak of equine influenza in 2011.equine influenza virus (eiv) is a major cause of respiratory disease in horses and the virus constantly undergoes antigenic drift. here we characterize and describe the ha1 and the na genes of h3n8 within samples obtained from outbreaks in sweden during november-december 2011. both clade 1 and clade 2 viruses of the florida sublineage were identified. the index case of clade 2 was transported to sweden from spain through the netherlands, whereas the clade 1 had its origin from a swedish stud far ...201626854337
ns-gene based phylogenetic analysis of equine influenza viruses isolated in poland.the phylogenetic analysis of influenza virus is based mainly on the variable hemagglutinin or neuraminidase genes. however, some discrete evolutionary trends might be revealed when more conservative genes are considered. we compared all available in genbank database full length ns sequences of equine influenza virus including polish isolates. four nucleotides at positions a202, a237, t672 and a714 and three amino acids at positions h59, k71 and s216 which are also present in a/eq/pulawy/2006 and ...201626711034
sentinel model for influenza a virus monitoring in free-grazing ducks in thailand.influenza a virus (iav) can cause influenza in birds and mammals. in thailand, free-grazing ducks are known iav reservoirs and can spread viruses through frequent movements in habitats they share with wild birds. in this study, the sentinel model for iav monitoring was conducted over 4 months in two free-grazing duck flocks. iav subtypes h4n6 (n=1) and h3n8 (n=5) were isolated from sentinel ducks at the ages of 13 and 15 weeks. clinical signs of depression and ocular discharge were observed in t ...201626711026
serological survey for avian influenza in turkeys in three states of southwest nigeria.since the first outbreak of avian influenza (ai) in nigeria in 2006, there has been continuous monitoring of the disease in chickens with little attention given to turkeys. as part of on-going surveillance for ai in southwest nigeria, we used a competitive elisa to detect anti-ai virus antibodies in 520 turkey sera obtained from poultry farms in oyo, osun, and ondo states while haemagglutination inhibiting antibodies against low pathogenic ai viruses (lpaivs) were detected using h3n8 and h5n2 su ...201526664747
identification and genetic analysis of h3n8 subtype influenza viruses isolated from domestic pigeons in central china.a novel strain of h3n8 influenza virus was isolated from domestic pigeons during the avian influenza virus (aiv) surveillance in wet markets in anhui, china, during 2013. the virus was characterized by whole-genome sequencing with subsequent genetic comparison and phylogenetic analysis. phylogenetic analysis revealed that the na gene of aiv mapped to the north american lineage, and the remaining seven genes belong to a eurasian lineage. these findings indicated that this h3n8 virus is a novel na ...201626611442
evaluation of twenty-two rapid antigen detection tests in the diagnosis of equine influenza caused by viruses of h3n8 subtype.equine influenza (ei) is a highly contagious disease caused by viruses of the h3n8 subtype. the rapid diagnosis of ei is essential to reduce the disease spread. many rapid antigen detection (rad) tests for diagnosing human influenza are available, but their ability to diagnose ei has not been systematically evaluated.201626568369
isolation and characterization of influenza a viruses from environmental water at an overwintering site of migratory birds in japan.the izumi plain in kagoshima prefecture, japan, is an overwintering site of more than 10,000 cranes. the wet paddy areas are artificially created to provide roosting sites for the cranes every winter. since wild ducks, known to be a natural reservoir of influenza a viruses, also overwinter in this area, the cranes' roost water likely serves as a source of influenza a virus infection. to assess this potential risk, we collected 126 water samples from the cranes' roost in the 2012/2013 winter seas ...201526392284
antibody responses after vaccination against equine influenza in the republic of korea in this study, antibody responses after equine influenza vaccination were investigated among 1,098 horses in korea using the hemagglutination inhibition (hi) assay. the equine influenza viruses, a/equine/south africa/4/03 (h3n8) and a/equine/wildeshausen/1/08 (h3n8), were used as antigens in the hi assay. the mean seropositive rates were 91.7% (geometric mean antibody levels (gmt), 56.8) and 93.6% (gmt, 105.2) for a/equine/south africa/4/03 and a/equine/wildeshausen/1/08, respectively. yearlings ...201526062436
intranasal immunization with pressure inactivated avian influenza elicits cellular and humoral responses in mice.influenza viruses pose a serious global health threat, particularly in light of newly emerging strains, such as the avian influenza h5n1 and h7n9 viruses. vaccination remains the primary method for preventing acquiring influenza or for avoiding developing serious complications related to the disease. vaccinations based on inactivated split virus vaccines or on chemically inactivated whole virus have some important drawbacks, including changes in the immunogenic properties of the virus. to induce ...201526056825
genetic evolution of equine influenza strains isolated in france from 2005 to 2010.reason for performing this study: equine influenza virus (eiv) is considered the most economically important equine respiratory pathogen worldwide. the h3n8 subtype, responsible for all outbreaks of equine influenza globally, evolves perpetually. mutations in the genome of these viruses have the potential to modify their antigenic properties and recognition by pre-existing antibodies.201525763436
structural and functional analysis of surface proteins from an a(h3n8) influenza virus isolated from new england harbor late 2011, an a(h3n8) influenza virus infection resulted in the deaths of 162 new england harbor seals. virus sequence analysis and virus receptor binding studies highlighted potential markers responsible for mammalian adaptation and a mixed receptor binding preference (s. j. anthony, j. a. st leger, k. pugliares, h. s. ip, j. m. chan, z. w. carpenter, i. navarrete-macias, m. sanchez-leon, j. t. saliki, j. pedersen, w. karesh, p. daszak, r. rabadan, t. rowles, w. i. lipkin, mbio 3:e00166-0011 ...201525540377
equine influenza a(h3n8) virus isolated from bactrian camel, mongolia.because little is known about the ecology of influenza viruses in camels, 460 nasal swab specimens were collected from healthy (no overt illness) bactrian camels in mongolia during 2012. one specimen was positive for influenza a virus (a/camel/mongolia/335/2012[h3n8]), which is phylogenetically related to equine influenza a(h3n8) viruses and probably represents natural horse-to-camel transmission.201425418532
equine influenza a(h3n8) virus infection in cats.interspecies transmission of equine influenza a(h3n8) virus has resulted in establishment of a canine influenza virus. to determine if something similar could happen with cats, we experimentally infected 14 cats with the equine influenza a(h3n8) virus. all showed clinical signs, shed virus, and transmitted the virus to a contact cohort.201425417790
contact heterogeneity, rather than transmission efficiency, limits the emergence and spread of canine influenza shifts in influenza virus are a major risk factor for pandemics. a key question in the study of emerging zoonoses is how the evolution of transmission efficiency interacts with heterogeneity in contact patterns in the new host species, as this interplay influences disease dynamics and prospects for control. here we use a synergistic mixture of models and data to tease apart the evolutionary and demographic processes controlling a host-range shift in equine h3n8-derived canine influenz ...201425340642
respiratory transmission of an avian h3n8 influenza virus isolated from a harbour seal.the ongoing human h7n9 influenza infections highlight the threat of emerging avian influenza viruses. in 2011, an avian h3n8 influenza virus isolated from moribund new england harbour seals was shown to have naturally acquired mutations known to increase the transmissibility of highly pathogenic h5n1 influenza viruses. to elucidate the potential human health threat, here we evaluate a panel of avian h3n8 viruses and find that the harbour seal virus displays increased affinity for mammalian recep ...201425183346
prevalence of canine influenza virus a (h3n8) in dogs in germany.the aim of this study was to investigate the prevalence of civ h3n8 in dogs in germany. blood samples from 272 clinically healthy dogs and 35 dogs with acute respiratory signs were screened for antibodies against influenza virus by elisa and haemagglutination inhibition (hi) assay; positive samples were further tested by fluorescent antibody test (fat) and subtype-specific hi assay. nasal and pharyngeal swabs from all sick dogs were submitted for real-time (rt)-pcr for influenza virus rna; pcr r ...201425155218
genetic characterization of a natural reassortant h3n8 avian influenza virus isolated from domestic geese in guangxi, southern china.a h3n8 subtype of avian influenza virus, a/goose/guangxi/020g/2009(h3n8) (gx020g), was isolated from the guangxi province of china in 2009. all eight gene segments of the gx020g strain were sequenced. sequence analysis indicated that this h3n8 virus is a novel reassortant strain. the genome sequences provide useful information for understanding the epidemiology and molecular characteristics of the h3n8 subtype of influenza virus in southern china.201425081261
diversity of interferon inducible mx gene in horses and association of variations with susceptibility vis-à-vis resistance against equine influenza infection.equine influenza (ei) is primarily an infection of the upper respiratory tract and is one of the major infectious respiratory diseases of economic importance in equines. re-emergence of the disease, species jumping by h3n8 virus in canines and possible threat of human pandemic due to the unpredictable nature of the virus have necessitated research on devising strategies for preventing the disease. the myxovirus resistance protein (mx) has been reported to confer resistance to orthomyxo virus inf ...201425064524
evolution of the hemagglutinin gene of h3n8 canine influenza virus in dogs.with the widespread use of a recently developed canine influenza virus (civ) h3n8 vaccine, continual molecular evaluation of circulating civs is necessary for monitoring antigenic drift. the aim of this project was to further describe the genetic evolution of civ, as well as determine any genetic variation within potential antigenic regions that might result in antigenic drift. to this end, the hemagglutinin gene of 19 civ isolates from dogs residing in colorado, new york, and south carolina hum ...201425056577
cleavage site and ectodomain of ha2 sub-unit sequence of three equine influenza virus isolated in morocco.the equine influenza (ei) is an infectious and contagious disease of the upper respiratory tract of horses. two outbreaks were notified in morocco during 1997 and 2004 respectively in nador and essaouira. the aims of the present study concern the amino acids sequences comparison with reference strain a/equine/miami/1963(h3n8) of the ha2 subunit including the cleavage site of three equine influenza viruses (h3n8) isolated in morocco: a/equine/nador/1/1997(h3n8), a/equine/essaouira/2/2004 (h3n8) a ...201425016480
evaluation of direct antiviral activity of the deva-5 herb formulation and extracts of five asian plants against influenza a virus h3n8.the herb formulation deva-5 is used in traditional medicine to treat acute infectious diseases. deva-5 is composed of five herbs: gentiana decumbens l., momordica cochinchinensis l., hypecoum erectum l., polygonum bistorta l., and terminalia chebula retz. deva-5 and its five components were investigated for in vitro antiviral activity against avian influenza a virus subtype h3n8.201425012588
virological evaluation of avian influenza virus persistence in natural and anthropic ecosystems of western siberia (novosibirsk region, summer 2012).wild aquatic birds, reservoir of low-pathogenicity (lp) avian influenza viruses (aivs), congregate in huge numbers in western siberia wetlands, where major intra- and inter-continental bird flyways overlap. in 2005 and 2006, highly pathogenic (hp) aiv h5n1 epizootics affected wild and domestic birds in the novosibirsk region. in 2012, we evaluated aiv persistence in siberian natural and anthropic ecosystems.201424972026
equine influenza serological methods.serologic tests for equine influenza virus (eiv) antibodies are used for many purposes, including retrospective diagnosis, subtyping of virus isolates, antigenic comparison of different virus strains, and measurement of immune responses to eiv vaccines. the hemagglutination-inhibition (hi), single radial hemolysis (srh), and serum micro-neutralization tests are the most widely used for these purposes and are described here. the presence of inhibitors of hemagglutination in equine serum complicat ...201424899450
type a influenza virus detection from horses by real-time rt-pcr and insulated isothermal rt-pcr.equine influenza (ei) is a highly contagious disease of horses caused by the equine influenza virus (eiv) h3n8 subtype. ei is the most important respiratory virus infection of horses and can disrupt major equestrian events and cause significant economic losses to the equine industry worldwide. influenza h3n8 virus spreads rapidly in susceptible horses and can result in very high morbidity within 24-48 h after exposure to the virus. therefore, rapid and accurate diagnosis of ei is critical for im ...201424899448
a brief introduction to equine influenza and equine influenza viruses.equine influenza virus (eiv) is a common respiratory pathogen of horses and other equids in most parts of the world. eiv are type a influenza viruses and two subtypes are known: h3n8 and h7n7. both are believed to have evolved from avian influenza virus ancestors. the h3n8 subtype circulates widely, but the h7n7 subtype is thought to be extinct. the clinical disease in horses, caused by either subtype, is an upper respiratory infection of varying severity depending upon the immune status of the ...201424899445
infection and pathogenesis of canine, equine, and human influenza viruses in canine tracheas.influenza a viruses (iavs) can jump species barriers and occasionally cause epidemics, epizootics, pandemics, and panzootics. characterizing the infection dynamics at the target tissues of natural hosts is central to understanding the mechanisms that control host range, tropism, and virulence. canine influenza virus (civ; h3n8) originated after the transfer of an equine influenza virus (eiv) into dogs. thus, comparing civ and eiv isolates provides an opportunity to study the determinants of infl ...201424899186
presence of respiratory viruses in equines in brazil.equines are susceptible to respiratory viruses such as influenza and parainfluenza. respiratory diseases have adversely impacted economies all over the world. this study was intended to determine the presence of influenza and parainfluenza viruses in unvaccinated horses from some regions of the state of são paulo, brazil. blood serum collected from 72 equines of different towns in this state was tested by hemagglutination inhibition test to detect antibodies for both viruses using the correspond ...201524878995
a synchronized global sweep of the internal genes of modern avian influenza virus.zoonotic infectious diseases such as influenza continue to pose a grave threat to human health. however, the factors that mediate the emergence of rna viruses such as influenza a virus (iav) are still incompletely understood. phylogenetic inference is crucial to reconstructing the origins and tracing the flow of iav within and between hosts. here we show that explicitly allowing iav host lineages to have independent rates of molecular evolution is necessary for reliable phylogenetic inference of ...201424531761
failure of transmission of low-pathogenic avian influenza virus between mallards and freshwater snails: an experimental aquatic bird populations, the ability of avian influenza (ai) viruses to remain infectious in water for extended periods provides a mechanism that allows viral transmission to occur long after shedding birds have left the area. however, this also exposes other aquatic organisms, including freshwater invertebrates, to ai viruses. previous researchers found that ai viral rna can be sequestered in snail tissues. using an experimental approach, we determined whether freshwater snails (physa acuta ...201324502718
development of a surveillance scheme for equine influenza in the uk and characterisation of viruses isolated in europe, dubai and the usa from 2010-2012.equine influenza viruses are a major cause of respiratory disease in horses worldwide and undergo antigenic drift. several outbreaks of equine influenza occurred worldwide during 2010-2012, including in vaccinated animals, highlighting the importance of surveillance and virus characterisation. virus isolates were characterised from more than 20 outbreaks over a 3-year period, including strains from the uk, dubai, germany and the usa. the haemagglutinin-1 (ha1) sequence of all isolates was determ ...201424480583
epidemiology and ecology of h3n8 canine influenza viruses in us shelter dogs.h3n8 canine influenza virus (civ) infection might contribute to increased duration of shelter stay for dogs. greater understanding of factors contributing to civ within shelters could help veterinarians identify control measures for civ.201724467389
co-infection of mallards with low-virulence newcastle disease virus and low-pathogenic avian influenza virus.waterfowl are considered the natural reservoir of low-virulence newcastle disease viruses (londvs) and low-pathogenic avian influenza viruses (lpaivs). the objective of this study was to investigate the effect of co-infections with londv and lpaiv on the infectivity and excretion of these viruses in mallards. one-month-old mallards were inoculated intranasally with 10(6) median embryo infectious doses of a wild-bird-origin londv and a/mallard/mn/199106/99 (h3n8) lpaiv on the same day or received ...201424467249
little evidence of human infection with equine influenza during the 2007 epizootic, queensland, australia.equine influenza virus (eiv) is considered enzootic in europe (except iceland), asia, north africa, and north and south america. when eiv outbreaks occur they may severely impact the equine and tourist industries. australia faced its first eiv outbreak beginning in august of 2007. the outbreak was concentrated in new south wales and queensland, with more than 1400 confirmed eiv infections in horses during the first month. rapid response from the equine industry and the federal government was suc ...201424360918
the genetics of virus particle shape in equine influenza a virus.many human strains of influenza a virus produce highly pleomorphic virus particles that at the extremes can be approximated as either spheres of around 100 nm diameter or filaments of similar cross-section but elongated to lengths of many microns. the role filamentous virions play in the virus life cycle remains enigmatic.201324224823
no evidence for zoonotic transmission of h3n8 canine influenza virus among us adults occupationally exposed to dogs.the zoonotic potential of h3n8 canine influenza virus (civ) has not been previously examined; yet considering the popularity of dogs as a companion animal and the zoonotic capabilities of other influenza viruses, the public health implications are great. this study aimed to determine the seroprevalence of antibodies against civ among a us cohort.201424237615
comparison of the infectivity and transmission of contemporary canine and equine h3n8 influenza viruses in dogs.phylogenetic analyses indicate that canine influenza viruses (civs) (h3n8) evolved from contemporary equine influenza virus (eiv). despite the genetic relatedness of eiv and civ, recent evidence suggests that civ is unable to infect, replicate, and spread among susceptible horses. to determine whether equine h3n8 viruses have equally lost the ability to infect, cause disease, and spread among dogs, we evaluated the infectivity and transmissibility of a recent florida sublineage eiv isolate in do ...201324198997
humoral response and antiviral cytokine expression following vaccination of thoroughbred weanlings--a blinded comparison of commercially available vaccines.previous studies in experimental ponies using interferon gamma (ifn-γ) as a marker for cell mediated immune (cmi) response demonstrated an increase in ifn-γ gene expression following vaccination with an iscom subunit, a canarypox recombinant and more recently, an inactivated whole virus vaccine. the objective of this study was to carry out an independent comparison of both humoral antibody and cmi responses elicited following vaccination with all these vaccine presentation systems. antibody resp ...201324021309
a novel reassortant h3n8 influenza virus isolated from drinking water for duck in a domestic duck farm in poyang lake conduct a full genome sequence analysis for genetic characterization of an h3n8 influenza virus isolated from drinking water of a domestic duck farm in poyang lake area in 2011.201323895699
exhaustive proteome mining for functional mhc-i ligands.we present the development and application of a new machine-learning approach to exhaustively and reliably identify major histocompatibility complex class i (mhc-i) ligands among all 20(8) octapeptides and in genome-derived proteomes of mus musculus , influenza a h3n8, and vesicular stomatitis virus (vsv). focusing on murine h-2k(b), we identified potent octapeptides exhibiting direct mhc-i binding and stabilization on the surface of tap-deficient rma-s cells. computationally identified vsv-deri ...201323772559
evaluation of virus isolation, one-step real-time reverse transcription polymerase chain reaction assay, and two rapid influenza diagnostic tests for detecting canine influenza a virus h3n8 shedding in dogs.sustained transmission of canine influenza a virus (civ) h3n8 among u.s. dogs underscores the threat influenza continues to pose to canine health. because rapid and accurate detection of infection is critical to the diagnosis and control of civ, the 2 main objectives of the current study were to estimate and compare the sensitivities of civ testing methods on canine swab samples and to evaluate the performance of flu detect™ (synbiotics corp., kansas city, mo) for detecting civ nasal shedding in ...201323536615
the seroprevalence of canine influenza virus h3n8 in dogs participating in a flyball tournament in pennsylvania in 2010: a follow-up study.canine influenza virus (civ) h3n8 infection is thought to be highly contagious and potentially deadly. low seroprevalence in dogs participating in the sport of flyball in 2009 was reported. it remains unknown if prevalence is changing in dogs at risk.201623425189
strain-related variation in the persistence of influenza a virus in three types of water: distilled water, filtered surface water, and intact surface water.the persistence of influenza a (ia) virus in aquatic habitats has been demonstrated to be a determinant for virus transmission dynamics in wild duck populations. in this study, we investigated virus strain-related variation in persistence in water for nine wild duck isolated ia viruses of three subtypes (h3n8, h4n6, and h8n4).201323289857
isolation and characterization of h3n8 equine influenza a virus associated with the 2011 epizootic in mongolia.equine influenza virus (eiv) epizootics affect 2.1 million mongolian horses approximately every 10 years and critically impact economy and nomadic livelihood of mongolia.201323289427
prevalence of and exposure factors for seropositivity to h3n8 canine influenza virus in dogs with influenza-like illness in the united estimate the seroprevalence of antibodies against h3n8 canine influenza virus (civ) in a population of us dogs with influenza-like illness (ili) and to identify factors associated with seropositivity.201323276098
protein expression changes in cells inoculated with equine influenza virus: antibody microarray analysis.changes in the level of cellular proteins in cells inoculated with equine influenza virus h7n7 and h3n8 were studied with microarray technique. h3n8 induced pro-apoptotic proteins while h7n7 induced both pro- as well as anti-apoptotic factors. the higher level of some cytoskeleton components and proteins involved in the protein quality control was recorded. relatively high number of proteins involved in the regulation of transcription was down-regulated. the pattern of changes observed for h7n7 ...201324597300
ecological factors driving avian influenza virus dynamics in spanish wetland ecosystems.studies exploring the ecological interactions between avian influenza viruses (aiv), natural hosts and the environment are scarce. most work has focused on viral survival and transmission under laboratory conditions and through mathematical modelling. however, more integrated studies performed under field conditions are required to validate these results. in this study, we combined information on bird community, environmental factors and viral epidemiology to assess the contribution of biotic an ...201223152749
intestinal excretion of a wild bird-origin h3n8 low pathogenic avian influenza virus in mallards (anas platyrhynchos).mallards (anas platyrhynchos) and other dabbling ducks in the genus anas are an important component of the wild bird reservoir for avian influenza (ai) virus; these viruses are maintained in migratory duck populations through a fecal-oral transmission route. we provide a detailed characterization of intestinal viral shedding in mallards infected with a wild bird-origin low pathogenic (lp) ai virus. five of eight, 1-mo-old mallards inoculated with a high dose of an h3n8 lp ai virus became infecte ...201223060500
molecular and phylogenetic analysis of matrix gene of avian influenza viruses isolated from wild birds and live bird markets in the usa.wild birds are the natural hosts for influenza a viruses (iavs) and provide a niche for the maintenance of this virus.201322958470
quantification of heterosubtypic immunity between avian influenza subtypes h3n8 and h4n6 in multiple avian host species.low-pathogenicity avian influenza virus (lpaiv) can lead to epizootics that cause economic losses in poultry or the emergence of human-infectious strains. lpaivs experience a complex immunity landscape as they are endemic in numerous host species, and many antigenically distinct strains co-circulate. prevention and control of emergence of detrimental strains requires an understanding of infection/transmission characteristics of the various subtypes in different hosts, including interactions betw ...201222956733
accelerated vaccination schedule provides protective levels of antibody and complete herd immunity to equine influenza.during the 2007 australian equine influenza (ei) outbreak, an accelerated primary course 14 day intervaccination schedule was proposed, but not widely implemented. expert opinion was divided as to the efficacy of such a schedule given the lack of published data. this study determined the level and duration of humoral immunity following administration of a recombinant canarypox-vectored vaccine (alvac-eiv) with a primary intervaccination interval of 14 days and booster at 105 days.201322943193
emergence of fatal avian influenza in new england harbor seals.from september to december 2011, 162 new england harbor seals died in an outbreak of pneumonia. sequence analysis of postmortem samples revealed the presence of an avian h3n8 influenza a virus, similar to a virus circulating in north american waterfowl since at least 2002 but with mutations that indicate recent adaption to mammalian hosts. these include a d701n mutation in the viral pb2 protein, previously reported in highly pathogenic h5n1 avian influenza viruses infecting people. lectin staini ...201222851656
effect of low-pathogenicity influenza virus h3n8 infection on mycoplasma gallisepticum infection of chickens.mycoplasma infection is still very common in chicken and turkey flocks. several low-pathogenicity avian influenza (lpai) viruses are circulating in wild birds that can be easily transmitted to poultry flocks. however, the effect of lpai on mycoplasma infection is not well understood. the aim of the present study was to investigate the infection of lpai virus h3n8 (a/mallard/hungary/19616/07) in chickens challenged with mycoplasma gallisepticum. two groups of chickens were aerosol challenged with ...201222845321
diagnostic performance of the canine influenza a virus subtype h3n8 hemagglutination inhibition assay.canine influenza a virus subtype h3n8 (h3n8 civ) was recognized in 2004 as a novel respiratory pathogen for dogs. to date, infections have been diagnosed in thousands of dogs in 38 u.s. states. diagnostic techniques such as reverse transcription polymerase chain reaction (rt-pcr) and virus isolation may yield false-negative results if samples are collected after virus shedding has ceased. therefore, serology is often necessary to confirm diagnosis. the hemagglutination inhibition (hi) assay is t ...201222529116
no evidence of horizontal infection in horses kept in close contact with dogs experimentally infected with canine influenza a virus (h3n8).since equine influenza a virus (h3n8) was transmitted to dogs in the united states in 2004, the causative virus, which is called canine influenza a virus (civ), has become widespread in dogs. to date, it has remained unclear whether or not civ-infected dogs could transmit civ to horses. to address this, we tested whether or not close contact between horses and dogs experimentally infected with civ would result in its interspecies transmission.201222506984
immunogenicity and clinical protection against equine influenza by dna vaccination of ponies.equine influenza a (h3n8) virus infection is a leading cause of respiratory disease in horses, resulting in widespread morbidity and economic losses. as with influenza in other species, equine influenza strains continuously mutate, often requiring the development of new vaccines. current inactivated (killed) vaccines, while efficacious, only offer limited protection against diverse subtypes and require frequent boosts. research into new vaccine technologies, including gene-based vaccines, aims t ...201222449425
development of a reverse transcription loop-mediated isothermal amplification assay for h7n7 equine influenza virus.we have developed a reverse transcription loop-mediated isothermal amplification (rt-lamp) assay for detecting h7n7 equine influenza virus (eiv). the detection limit of the rt-lamp assay was a virus dilution of 10(-4), which was 10 times more sensitive than that of espline influenza a&b-n and the same as that of reverse transcription polymerase chain reaction. the rt-lamp assay specifically amplified h7n7 eiv strains but did not amplify several pathogens related to equine respiratory disease inc ...201222362254
efficacy of a single intravenous dose of the neuraminidase inhibitor peramivir in the treatment of equine influenza.equine influenza a virus (eiv) of the h3n8 subtype is an important pathogen causing acute respiratory disease in horses. peramivir is a selective inhibitor of the influenza virus neuraminidase (na). the characteristics of peramivir are not only its capacity for parenteral administration, but also its strong affinity for na and slow off-rate from the na-peramivir complex, suggesting that it could lead to a prolonged inhibitory effect and thus allow a lower dosing frequency. the aims of this study ...201222326934
time-related pathological changes in horses experimentally inoculated with equine influenza a investigate the pathology of equine influenza, necropsy of 7 horses experimentally infected with equine influenza a virus (eiv) subtype h3n8 was conducted on post-infection days (pid) 2, 3, 7, and 14. histopathologically, rhinitis or tracheitis including epithelial degeneration or necrosis with loss of ciliated epithelia and a reduction in goblet cell numbers, was observed in the respiratory tracts on pids 2 and 3. epithelial hyperplasia or squamous metaplasia and suppurative bronchopneumonia ...201224833992
the use of equine influenza pseudotypes for serological screening.standard assays used for influenza serology present certain practical issues, such as inter-laboratory variability, complex protocols and the necessity for handling certain virus strains in high biological containment facilities. in an attempt to address this, avian and human influenza ha pseudotyped retroviruses have been successfully employed in antibody neutralization assays. in this study we generated an equine influenza pseudotyped lentivirus for serological screening. this was achieved by ...201223515229
emergence of h3n8 equine influenza virus in donkeys in china in 2017.equine influenza virus is a major respiratory pathogen in horses. although both horses and donkeys belong to the genus equus, donkey infection with influenza viruses is rare. in march 2017, an influenza outbreak occurred in donkeys in shandong province, china. the causative virus, a/donkey/shandong/1/2017(h3n8), was isolated from a dead donkey. genetic analysis indicated that the virus originated from influenza a (h3n8) clade 2 of the florida sub-lineage that has been circulating in asian equine ...201829408020
epidemiological survey of equine influenza in andalusia, spain.equine influenza is a highly contagious respiratory disease considered the most important respiratory disease in equids. although influenza a virus (iav) has caused outbreaks in equids worldwide, surveillance in these species in spain has not been conducted. a cross-sectional study was carried out to determine the individual and herd prevalence of antibodies against h3n8 and h7n7 iav in equids in andalusia (southern spain). antibodies againsts iav were measured by the single radial haemolysis as ...201829496107
detection of h3n8 influenza a virus with multiple mammalian-adaptive mutations in a rescued grey seal (halichoerus grypus) pup.avian influenza a viruses (iavs) in different species of seals display a spectrum of pathogenicity, from sub-clinical infection to mass mortality events. here we present an investigation of avian iav infection in a 3- to 4-month-old grey seal (halichoerus grypus) pup, rescued from st michael's mount, cornwall in 2017. the pup underwent medical treatment but died after two weeks; post-mortem examination and histology indicated sepsis as the cause of death. iav np antigen was detected by immunohis ...202032211197
detection of the epidemic of the h3n8 subtype of the equine influenza virus in large-scale donkey monitor the occurrence of equine influenza in large-scale donkey farms in liaocheng city, shandong province, serological investigation and sequence analysis of ha/m protein gene of equine influenza virus (eiv) were carried out. samples (n = 65) of the lung and nasal swab were collected in six different large-scale donkey farms and detected with rt-pcr for ha and m protein gene. the homology and evolution of ha and m genes were analysed with known sequences. antibody titres of serum samples (n ...202032341914
novel hpaiv h5n8 reassortant (clade detected in germany.a novel h5n8 highly pathogenic avian influenza virus (hpaiv) was detected in a greater white-fronted goose in january 2020 in brandenburg, germany, and, in february 2020, in domestic chickens belonging to a smallholding in baden-wuerttemberg, germany. full-genome sequencing was conducted on the minion platform, enabling further phylogenetic analyses. the virus of clade holds six segments from a eurasian/asian/african hpaiv h5n8 reassortant and two segments from low pathogenic avian infl ...202032143363
comparison among three different serological methods for the detection of equine influenza virus infection.the equine influenza virus (eiv) h3n8 subtype is responsible for all eiv outbreaks worldwide while the h7n7 subtype is less pathogenic and is considered extinct as it has not been confirmed in outbreaks since 1980. although eiv is enzootic in brazil, few reports describe the actual eiv antibody status in the country. the aims of this study were: - to evaluate the efficiency of different serum treatments described by the world organisation for animal health (oie) and the world health organization ...201730160701
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