| detection of pb2 627 k mutation in two highly pathogenic isolates of the h7n9 subtype influenza a virus from chickens in northern china. | | 2020 | 32828821 |
| continuous reassortment of clade 2.3.4.4 h5n6 highly pathogenetic avian influenza viruses demonstrating high risk to public health. | since it firstly emerged in china in 2013, clade 2.3.4.4 h5n6 highly pathogenic avian influenza viruses (hpaivs) has rapidly replaced predominant h5n1 to become the dominant h5 subtype in china, especially in ducks. not only endemic in china, it also crossed the geographical barrier and emerged in south korea, japan, and europe. here, we analyzed the genetic properties of the clade 2.3.4.4 h5n6 hpaivs with full genome sequences available online together with our own isolates. phylogenetic analys ... | 2020 | 32824873 |
| immunogenicity and efficacy comparison of mdck cell-based and egg-based live attenuated influenza vaccines of h5 and h7 subtypes in ferrets. | during a pandemic, the availability of specific pathogen free chicken eggs is a major bottleneck for up-scaling response to the demand for influenza vaccine. this has led us to explore the use of madin-darby canine kidney (mdck) cells for the manufacture of live attenuated influenza vaccine (laiv) that provides production flexibility and speed. the present study reports the comparison of the immunogenicity and efficacy of two mdck-based laivs against two egg-based laivs prepared from the same pa ... | 2020 | 32741671 |
| contribution of segment 3 to the acquisition of virulence in contemporary h9n2 avian influenza viruses. | h9n2 avian influenza viruses (aivs) circulate in poultry throughout much of asia, the middle east, and africa. these viruses cause huge economic damage to poultry production systems and pose a zoonotic threat both in their own right and in the generation of novel zoonotic viruses, for example, h7n9. in recent years, it has been observed that h9n2 viruses have further adapted to gallinaceous poultry, becoming more highly transmissible and causing higher morbidity and mortality. here, we investiga ... | 2020 | 32727875 |
| geographical variation in the risk of h7n9 human infections in china: implications for risk-based surveillance. | the influenza a (h7n9) subtype remains a public health problem in china affecting individuals in contact with live poultry, particularly at live bird markets. despite enhanced surveillance and biosecurity at lbms h7n9 viruses are now more widespread in china. this study aims to quantify the temporal relationship between poultry surveillance results and the onset of human h7n9 infections during 2013-2017 and to estimate risk factors associated with geographical risk of h7n9 human infections in co ... | 2020 | 32587266 |
| genetic and antigenic characterization of h5 and h7 avian influenza viruses isolated from migratory waterfowl in mongolia from 2017 to 2019. | the circulation of highly pathogenic avian influenza viruses (hpaivs) of various subtypes (e.g., h5n1, h5n6, h5n8, and h7n9) in poultry remains a global concern for animal and public health. migratory waterfowls play important roles in the transmission of these viruses across countries. to monitor virus spread by wild birds, active surveillance for avian influenza in migratory waterfowl was conducted in mongolia from 2015 to 2019. in total, 5000 fecal samples were collected from lakesides in cen ... | 2020 | 32430568 |
| development of high-growth influenza h7n9 prepandemic candidate vaccine viruses in suspension mdck cells. | influenza vaccine manufacturers traditionally use egg-derived candidate vaccine viruses (cvvs) to produce high-yield influenza viruses for seasonal or pandemic vaccines; however, these egg-derived cvvs need an adaptation process for the virus to grow in mammalian cells. the low yields of cell-based manufacturing systems using egg-derived cvvs remain an unsolved issue. this study aimed to develop high-growth cell-derived cvvs for mdck cell-based vaccine manufacturing platforms. | 2020 | 32241276 |
| intranasally administered protein coated chitosan nanoparticles encapsulating influenza h9n2 ha2 and m2e mrna molecules elicit protective immunity against avian influenza viruses in chickens. | chitosan nanoparticles (cnps) represent an efficient vaccination tool to deliver immunogenic antigens to the antigen-presenting cells (apcs), which subsequently stimulate protective immune responses against infectious diseases. herein, we prepared cnps encapsulating mrna molecules followed by surface coating with conserved h9n2 ha2 and m2e influenza proteins. we demonstrated that cnps efficiently delivered mrna molecules into apcs and had effectively penetrated the mucosal barrier to reach to th ... | 2020 | 32143695 |
| emergence of human avian influenza a(h7n9) virus infections in wenshan city in southwest china, 2017. | the emergence of human infection with avian influenza a(h7n9) virus was reported in wenshan city, southwestern china in 2017. the study describes the epidemiological and virological features of the outbreak and discusses the origin of the infection. | 2020 | 32075579 |
| the evolution and genetic diversity of avian influenza a(h9n2) viruses in cambodia, 2015 - 2016. | low pathogenic a(h9n2) subtype avian influenza viruses (aivs) were originally detected in cambodian poultry in 2013, and now circulate endemically. we sequenced and characterised 64 a(h9n2) aivs detected in cambodian poultry (chickens and ducks) from january 2015 to may 2016. all a(h9) viruses collected in 2015 and 2016 belonged to a new bj/94-like h9-4.2.5 sub-lineage that emerged in the region during or after 2013, and was distinct to previously detected cambodian viruses. overall, there was a ... | 2019 | 31815945 |
| process development for pandemic influenza vlp vaccine production using a baculovirus expression system. | influenza viruses cause hundreds of thousands of respiratory diseases worldwide each year, and vaccination is considered the most effective approach for preventing influenza annual epidemics or pandemics. since 1950, chicken embryonated eggs have been used as the main method for producing seasonal influenza vaccines. however, this platform has the main drawback of a lack of scale-up flexibility, and thus, egg-based vaccine manufacturers cannot supply sufficient doses within a short period for us ... | 2019 | 31666806 |
| amino acid mutations a286v and t437m in the nucleoprotein attenuate h7n9 viruses in mice. | the low-pathogenic h7n9 influenza viruses that emerged in 2013 acquired an insertion of four amino acids in their hemagglutinin cleavage site and thereby became highly pathogenic to chickens in 2017. previous studies indicated that these highly pathogenic h7n9 viruses are virulent in chickens but have distinct pathotypes in mice. a/chicken/guangdong/sd098/2017 (ck/sd098) is avirulent, with a 50% mouse lethal dose (mld50) of >7.5 log10 50% egg infectious dose (eid50), whereas a/chicken/hunan/s122 ... | 2020 | 31666373 |
| antigenic variation of avian influenza a(h5n6) viruses, guangdong province, china, 2014-2018. | market surveillance showed continuing circulation of avian influenza a(h5n6) virus in live poultry markets in guangdong province in 2017, despite compulsory vaccination for avian influenza a(h5nx) and a(h7n9). we analyzed h5n6 viruses from 2014-2018 from guangdong province, revealing antigenic drift and decreased antibody response against the vaccine strain in vaccinated chickens. | 2019 | 31538920 |
| a field-deployable insulated isothermal rt-pcr assay for identification of influenza a (h7n9) shows good performance in the laboratory. | avian influenza a (h7n9) remains circulating in china. for countries at risk of introduction of h7n9, such as vietnam, early detection of h7n9 virus is essential for the early containment of the virus. insulated isothermal reverse transcriptase pcr (iirt-pcr) is a portable pcr system that can be deployed under field conditions to identify pathogens at the sampling site. applying pcr at the sampling site will greatly reduce the time to obtain a diagnostic result which allows the veterinary author ... | 2019 | 31487118 |
| novel reassortant h7n2 originating from the h7n9 highly pathogenic avian influenza viruses in china, 2019. | | 2019 | 31473272 |
| the pb2 and m genes of genotype s h9n2 virus contribute to the enhanced fitness of h5nx and h7n9 avian influenza viruses in chickens. | genotype s h9n2 viruses frequently donate their internal genes to facilitate the generation of novel influenza viruses, e.g., h5n6, h7n9, and h10n8, which have caused human infection. genotype s was originated from the replacement of f/98-like m and pb2 genes of the genotype h with those from g1-like lineage. however, whether this gene substitution will influence the viral fitness of emerging influenza viruses remains unclear. we found that h5nx and h7n9 viruses with g1-like pb2 or m gene exhibi ... | 2019 | 31325836 |
| a single amino acid substitution at residue 218 of hemagglutinin improves the growth of influenza a(h7n9) candidate vaccine viruses. | the potential avian influenza pandemic remains a threat to public health, as the avian-origin influenza a(h7n9) virus has caused more than 1,560 laboratory-confirmed human infections since 2013, with nearly 40% mortality. development of low-pathogenic candidate vaccine viruses (cvvs) for vaccine production is essential for pandemic preparedness. however, the suboptimal growth of cvvs in mammalian cells and chicken eggs is often a challenge. by introducing a single adaptive substitution, g218e, i ... | 2019 | 31270231 |
| single immunization with newcastle disease virus-vectored h7n9 vaccine confers a complete protection against challenge with highly pathogenic avian influenza h7n9 virus. | in the fifth wave of the h7n9 avian influenza epidemic, highly pathogenic avian influenza (hpai) a (h7n9) viruses have emerged and pose a great challenge to public health and the poultry industry. in addition, there are apparent genetic and antigenic variations between the classical h7n9 avian influenza virus and the newly-emerged h7n9 virus. therefore, an antigenic-match vaccine is required for the prevention and control of h7n9 avian influenza in poultry in china. in this study, a recombinant ... | 2019 | 31251520 |
| chinese poultry farmers' decision-making for avian influenza prevention: a qualitative analysis. | poultry farmers faced dual risk when mutant avian influenza (ai) virus showed the zoonotic characteristics. a/h5n1 and a/h7n9 were two dominant ai virus strains that have captured the attention of the public over the years for they have been reported to bring about greater loss to poultry and human, respectively. previous studies mainly used quantitative methods investigating either the means that poultry farmers adopted for protecting their poultry against a/h5n1 infection or the poultry farmer ... | 2019 | 31215154 |
| emergence of waterfowl-originated gene cassettes in hpai h7n9 viruses caused severe human infection in fujian, china. | highly pathogenic avian influenza (hpai) a(h7n9) virus emerged and caused human infections during the 2016-2017 epidemic wave of influenza a(h7n9) viruses in china. we report a human infection with hpai h7n9 virus and six environmental isolates in fujian province, china. | 2019 | 31187583 |
| human-derived a/guangdong/th005/2017 (h7n9) exhibits extremely high replication in the lungs of ferrets and is highly pathogenic in chickens. | after a series of studies on the pathogenicity of several h7n9 strains from 2013 to 2018, we wanted to dynamically track the pathogenicity of a/guangdong/th005/2017 in ferrets and poultry. the pathogenicity and transmissibility of th005, especially the distribution and replication in tissues, were studied in ferrets. we also aimed to assess the level of th005 pathogenicity in chickens. the results showed that the pathogenicity of th005 was significantly increased in ferrets and chickens, especia ... | 2019 | 31146467 |
| the pathogenesis of h7 highly pathogenic avian influenza viruses in lesser scaup (aythya affinis). | waterfowl are the natural hosts of avian influenza virus (aiv), and through migration spread the virus worldwide. most aivs carried by wild waterfowl are low pathogenic strains; however, goose/guangdong/1996 lineage clade 2.3.4.4 h5 highly pathogenic (hp) aiv now appears to be endemic in wild birds in much of the eastern hemisphere. most research efforts studying aiv pathogenicity in waterfowl thus far have been directed toward dabbling ducks. in order to better understand the role of diving duc ... | 2019 | 31131581 |
| better fit of codon usage of the polymerase and nucleoprotein genes to the chicken host for h7n9 than h9n2 aivs. | | 2019 | 31125636 |
| a hospital cluster combined with a family cluster of avian influenza h7n9 infection in anhui province, china. | to identify human-to-human transmission of h7n9 avian influenza virus, we investigated a hospital cluster combined with family cluster in this study. | 2019 | 31100362 |
| prevalence of h7n9 subtype avian influenza viruses in poultry in china, 2013-2018. | h7n9 subtype avian influenza viruses (aiv) circulating in china over recent years have had an enormous impact on public health and economy. during the period between november 2016 and april 2017, an increase in human infections caused by these viruses was reported, with rapid emergence and spread of variants in china. consequently, the government of china implemented a controversial vaccination strategy in september 2017. here, we provide evidence of the prevalence of h7n9 aivs in china based on ... | 2019 | 30903740 |
| amino acid substitutions n123d and n149d in hemagglutinin molecule enhance immunigenicity of live attenuated influenza h7n9 vaccine strain in experiment. | we compared three cold-adapted live attenuated influenza vaccine strains prepared by reverse genetics methods on the basis of master donor virus a/leningrad/134/17/57 and influenza h7n9 strains a/anhui/1/2013 and a/shanghai/1/2013. two strains based on a/anhui/1/2013 differed by amino acid positions 123 and 149 in ha1 (123n/149n; 123d/149d). all strains efficiently replicated in developing chicken embryos; a/shanghai/1/2013-based strain and a/anhui/1/2013-123n/149n variant were characterized by ... | 2019 | 30903496 |
| knowledge, attitudes, and practices associated with avian influenza along the live chicken market chains in eastern china: a cross-sectional survey in shanghai, anhui, and jiangsu. | the avian influenza (ai) virus of the h7n9 subtype emerged in china in 2013. live bird markets (lbms) selling live meat chickens were indicated to present a high-risk of the virus dissemination. this study aimed to quantify the level of knowledge, attitudes, and practices (kap) on ai and to measure the associated risk factors among different actors along the live chicken market chain within h7n9-affected eastern provinces in china. a cross-sectional survey was conducted in these provinces from j ... | 2019 | 30891947 |
| influenza a(h7n9) virus emerged and resulted in human infections in chongqing, southwestern china since 2017. | influenza a(h7n9) virus has emerged and resulted in human infections in chongqing, southwestern china since 2017. this study aimed to describe the epidemiological characteristics of the first epidemic in this region. | 2019 | 30797966 |
| pathogenicity and transmissibility of north american h7 low pathogenic avian influenza viruses in chickens and turkeys. | low pathogenic avian influenza (lpai) viruses can silently circulate in poultry and wild aquatic birds and potentially mutate into highly pathogenic avian influenza (hpai) viruses. in the u.s., recent emergence and spread of h7n8 and h7n9 hpai viruses not only caused devastating losses to domestic poultry but also underscored the capability of lpai viruses to mutate into hpai viruses. therefore, in this study, we evaluated pathogenicity and transmissibility of h7n8 and h7n9 lpai viruses (the pro ... | 2019 | 30781528 |
| an avian influenza virus a(h7n9) reassortant that recently emerged in the united states with low pathogenic phenotype does not efficiently infect swine. | in 2017, outbreaks of low and highly pathogenic avian h7n9 viruses were reported in four states in the united states. in total, over 270 000 birds died or were culled, causing significant economic loss. the potential for avian-to-swine transmission of the u.s. avian h7n9 was unknown. in an experimental challenge in swine using a representative low pathogenic h7n9 (a/chicken/tennessee/17-007431-3/2017; lpai tn/17) isolated from these events, no infectious virus in the upper and minimal virus in t ... | 2019 | 30761746 |
| recombinant baculovirus vaccine expressing hemagglutinin of h7n9 avian influenza virus confers full protection against lethal highly pathogenic h7n9 virus infection in chickens. | the emergent highly pathogenic avian influenza a (h7n9) (hpai) virus is a major public concern in china. therefore, it is crucially important to develop an effective vaccine against this virus. in this study, we constructed a baculovirus vaccine expressing the hemagglutinin (ha) of h7n9 strain a/chicken/jiaxing/148/2014 (jx148). the recombinant baculovirus (rbac-jx148ha) generated in this study showed good growth in insect cells and good safety, and it stably expressed the ha protein. we compare ... | 2019 | 30671655 |
| closure of live bird markets leads to the spread of h7n9 influenza in china. | following the emergence of h7n9 influenza in march 2013, local animal and public health authorities in china have been closing live bird markets as a measure to try to control the h7n9 influenza epidemic. the role of live bird market (lbm) closure on the spread of n7n9 influenza following the closure of lbms during march to may 2013 (the first wave) and october 2013 to march 2014 (the second wave) is described in this paper. different provinces implemented closure actions at different times, and ... | 2018 | 30540847 |
| deciphering the sharp decrease in h7n9 human infections. | the h7n9 virus has caused five waves of human infections since 2013. however, human infections have almost disappeared in the past year. in a recent study, shi et al. revealed that the usage of a bivalent h5/h7 vaccine successfully prevented chicken infections, and thus prevented, and nearly eliminated, human infections. | 2018 | 30472993 |
| vaccination of poultry successfully eliminated human infection with h7n9 virus in china. | the h7n9 viruses that emerged in china in 2013 were nonpathogenic in chickens but mutated to a highly pathogenic form in early 2017 and caused severe disease outbreaks in chickens. the h7n9 influenza viruses have caused five waves of human infection, with almost half of the total number of human cases (766 of 1,567) being reported in the fifth wave, raising concerns that even more human infections could occur in the sixth wave. in september 2017, an h5/h7 bivalent inactivated vaccine for chicken ... | 2018 | 30414008 |
| two novel reassortant high pathogenic h7n9 viruses isolated in southern china in fifth wave shows internal genomic diversity and high virulence in chickens and ducks. | | 2018 | 30391631 |
| identifying key bird species and geographical hotspots of avian influenza a (h7n9) virus in china. | in china since the first human infection of avian influenza a (h7n9) virus was identified in 2013, it has caused serious public health concerns due to its wide spread and high mortality rate. evidence shows that bird migration plays an essential role in global spread of avian influenza viruses. accordingly, in this paper, we aim to identify key bird species and geographical hotspots that are relevant to the transmission of avian influenza a (h7n9) virus in china. | 2018 | 30305184 |
| amino acid residue 217 in the hemagglutinin glycoprotein is a key mediator of avian influenza h7n9 virus antigenicity. | avian influenza viruses continue to evolve and acquire mutations that facilitate antigenic drift and virulence change. in 2017, low-pathogenicity h7n9 avian influenza viruses evolved to a high-pathogenicity phenotype in china. comparative antigenic analysis of the low- and high-pathogenicity virus strains showed marked variability. in order to identify residues that may be linked to the antigenic change among the h7n9 viruses, we serially passaged the viruses in the presence of homologous ferret ... | 2019 | 30282714 |
| rapid evolution of h7n9 highly pathogenic viruses that emerged in china in 2017. | h7n9 low pathogenic influenza viruses emerged in china in 2013 and mutated to highly pathogenic strains in 2017, resulting in human infections and disease in chickens. to control spread, a bivalent h5/h7 inactivated vaccine was introduced in poultry in september 2017. to monitor virus evolution and vaccine efficacy, we collected 53,884 poultry samples across china from february 2017 to january 2018. we isolated 252 h7n9 low pathogenic viruses, 69 h7n9 highly pathogenic viruses, and one h7n2 high ... | 2018 | 30269969 |
| hemagglutinin characteristics, changes in pathogenicity, and antigenic variation of highly pathogenic h7n9 avian influenza viruses in china. | | 2019 | 30267798 |
| a family cluster of two fatal cases infected with influenza a (h7n9) virus in kunming china, 2017. | two imported family cases (mother and daughter) of fatal h7n9 infection in kunming, china were reported in 2017. epidemiological investigation showed that the two family members had both been exposed to sick chickens in a poultry market. the onset of illness and death of the mother was 7 days later than her daughter, raising concerns about human-to-human transmission of h7n9 in the locality. sequence alignment and phylogenetic analysis of the virus strains isolated from the two patients revealed ... | 2018 | 30248474 |
| protective efficacy of an inactivated chimeric h7/h5 avian influenza vaccine against highly pathogenic avian influenza h7n9 and clade 2.3.4.4 h5 viruses. | the highly pathogenic avian influenza (hpai) h5 and h7n9 viruses pose a serious challenge to public health and the poultry industry in china. in this study, we generated a chimeric h7/h5 recombinant virus that expressed the entire ha1 region of the hpai a/chicken/guangdong/rz/2017(h7n9) virus and the ha2 region of the hpai a/chicken/fujian/5/2016(h5n6) viruses. the resulting chimeric pr8-h7/h5 virus exhibited similar growth kinetics as the parental pr8-h5 and pr8-h7 viruses in vitro. the inactiv ... | 2018 | 30173747 |
| pathobiology of tennessee 2017 h7n9 low and high pathogenicity avian influenza viruses in commercial broiler breeders and specific pathogen free layer chickens. | in march 2017, h7n9 highly pathogenic avian influenza (hpai) virus was detected in 2 broiler breeder farms in the state of tennessee, usa. subsequent surveillance detected the low pathogenicity avian influenza (lpai) virus precursor in multiple broiler breeder farms and backyard poultry in tennessee and neighboring states. the pathogenesis of the h7n9 lpai virus was investigated in commercial broiler breeders, the bird type mostly affected in this outbreak. infectivity, transmissibility, and pat ... | 2018 | 30157963 |
| severe human infection with a novel avian-origin influenza a(h7n4) virus. | human infections with influenza h7 subtypes, such as h7n9, have raised concerns worldwide. here, we report a human infection with a novel influenza a(h7n4) virus. a 68 years-old woman with cardiovascular and cholecystic comorbidities developed rapidly progressed pneumonia with influenza-like-illness as initial symptom, recovered after 23 days-hospitalization including 8 days in icu. laboratory indicators for liver and blood coagulation dysfunction were observed. oseltamivir phosphate, glucocorti ... | 2018 | 32288966 |
| corrigendum: mucosal and systemic immune responses to influenza h7n9 antigen ha1-2 co-delivered intranasally with flagellin or polyethyleneimine in mice and chickens. | [this corrects the article doi: 10.3389/fimmu.2017.00326.]. | 2018 | 30131811 |
| enhanced th1/th2 mixed immune responses elicited by polyethyleneimine adjuvanted influenza a (h7n9) antigen ha1-2 in chickens. | influenza a (h7n9) viruses have caused severe human infections and deaths every year in china since 2013. to reduce the risk of human infection and prevent a new influenza pandemic, there is a pressing need to develop safe and effective anti-h7n9 vaccines for poultry. polyethyleneimine (pei) is an organic polycation used extensively as a transfection reagent for decades. although the adjuvant potential of pei is well studied in mammals, its applicability and immune characteristics to avian speci ... | 2018 | 30085299 |
| genetic and biological characterization of h9n2 avian influenza viruses isolated in china from 2011 to 2014. | the genotypes of the h9n2 avian influenza viruses have changed since 2013 when almost all h9n2 viruses circulating in chickens in china were genotype 57 (g57) with the fittest lineage of each gene. to characterize the h9n2 variant viruses from 2011 to 2014, 28 h9n2 influenza viruses were isolated from live poultry markets in china from 2011-2014 and were analyzed by genetic and biological characterization. our findings showed that 16 residues that changed antigenicity, two potential n-linked gly ... | 2018 | 29969454 |
| [a case of human infection with highly pathogenic avian influenza a (h7n9) virus through poultry processing without protection measure]. | objective: to investigate the infection pattern and etiological characteristics of a case of human infection with highly pathogenic avian influenza a (h7n9) virus and provide evidence for the prevention and control of human infection with highly pathogenic avian influenza virus. methods: epidemiological investigation was conducted to explore the case's exposure history, infection route and disease progression. samples collected from the patient, environments and poultry were tested by using real ... | 2018 | 29936750 |
| h7n9 avian influenza virus is efficiently transmissible and induces an antibody response in chickens. | h7n9 viruses pose a threat to human health and they are no less harmful to the poultry industry than the h5n1 avian influenza viruses. however, the pathogenesis, transmissibility, and the host immune response of the h7n9 virus in chickens and mice remain unclear. in this study, we found that h7n9 viruses replicated in multiple organs of the chicken and viral shedding persisted up to 30 days postinoculation (dpi). the viruses were efficiently transmitted between chickens through direct contact. n ... | 2018 | 29706970 |
| influenza viral vectors expressing two kinds of ha proteins as bivalent vaccine against highly pathogenic avian influenza viruses of clade 2.3.4.4 h5 and h7n9. | the h5 and h7n9 subtypes of highly pathogenic avian influenza viruses (hpaivs) in china pose a serious challenge to public health and the poultry industry. in this study, a replication competent recombinant influenza a virus of the í5n1 subtype expressing the h7 ha1 protein from a tri-cistronic ns segment was constructed. a heterologous dimerization domain was used to combine with the truncated ns1 protein of 73 amino acids to increase protein stability. h7 ha1, nuclear export protein coding reg ... | 2018 | 29670587 |
| does eating chicken feet with pickled peppers cause avian influenza? observational case study on chinese social media during the avian influenza a (h7n9) outbreak. | a hot topic on the relationship between a popular avian-origin food and avian influenza occurred on social media during the outbreak of the emerging avian influenza a (h7n9). the misinformation generated from this topic had caused great confusion and public concern. | 2018 | 29599109 |
| evolutionary pathway for the 2017 emergence of a novel highly pathogenic avian influenza a(h7n9) virus among domestic poultry in tennessee, united states. | in march 2017, a novel highly pathogenic avian influenza a(h7n9) virus was detected at two commercial broiler breeder facilities in tennessee, united states. in this study, a wild bird low pathogenic avian influenza a virus, a/blue-winged teal/wyoming/ah0099021/2016(h7n9), was shown to be the probable precursor of the novel h7n9 virus; this low pathogenic virus has eight possible progenitor genes sharing > 99% sequence identity with the novel h7n9 virus. phylogeographic analyses showed that vira ... | 2018 | 30236990 |
| interleukin 12-containing influenza virus-like-particle vaccine elevate its protective activity against heterotypic influenza virus infection. | to produce monovalent and bivalent influenza vaccines composed of virus-like particles (vlps) containing hemagglutinin (ha), we generated four recombinant baculoviruses derived from bombyx mori nuclear polyhedrosis virus (bmnpv) and autographa california nuclear polyhedrosis virus (acnpv). monovalent fukushima (a/tufted duck/fukushima/16/2011 [h5n1]) (fkh5) and anhui (a/anhui/1/2013 [h7n9]) (anh7) vlp influenza vaccines were produced in silkworm pupae infected with fkh5-bmnpv or anh7-bmnpv. to p ... | 2020 | 32802975 |
| h9n2 influenza virus spillover into wild birds from poultry in china bind to human-type receptors and transmit in mammals via respiratory droplets. | h9n2 influenza virus has been reported worldwide for several decades, and it has evolved into multiple genotypes among domestic poultry. however, the study involving ecology and evolution of low pathogenic avian influenza virus h9n2 in wild birds in china is limited. here, we carried out surveillance of avian influenza virus h9n2 in wild birds along with the east asian-australian migratory flyway in china in 2017. to estimate the prevalence of h9n2 avian virus in wild birds, information on expos ... | 2021 | 33566453 |
| pathogenesis and genetic characteristics of a novel reassortant low pathogenic avian influenza a(h7n6) virus isolated in cambodia in 2019. | the first human case of zoonotic a(h7n4) avian influenza virus (aiv) infection was reported in early 2018 in china. two months after this case, novel a(h7n4) viruses phylogenetically related to the jiangsu isolate emerged in ducks from live bird markets in cambodia. during active surveillance in cambodia, a novel a(h7n6) reassortant of the zoonotic low pathogenic aiv (lpaiv) a(h7n4) was detected in domestic ducks at a slaughterhouse. complete genome sequencing and phylogenetic analysis showed th ... | 2021 | 34347386 |
| virus adaptation following experimental infection of chickens with a domestic duck low pathogenic avian influenza isolate from the 2017 usa h7n9 outbreak identifies polymorphic mutations in multiple gene segments. | in march 2017, highly pathogenic (hp) and low pathogenic (lp) avian influenza virus (aiv) subtype h7n9 were detected from poultry farms and backyard birds in several states in the southeast united states. because interspecies transmission is a known mechanism for evolution of aivs, we sought to characterize infection and transmission of a domestic duck-origin h7n9 lpaiv in chickens and genetically compare the viruses replicating in the chickens to the original h7n9 clinical field samples used as ... | 2021 | 34207098 |
| the pb2 co-adaptation of h10n8 avian influenza virus increases the pathogenicity to chickens and mice. | avian influenza (ai) is an important zoonotic disease, which can be transmitted across species barriers to other hosts, especially humans, posing a serious threat to the poultry industry and public health. in recent years, human cases infected with the h10n8, h9n2, and h7n9 of avian influenza viruses (aivs) have been identified frequently as have the internal genes of h7n9 and h10n8, which are derived from h9n2 viruses. the adaptive mutation of the pb2 gene is an important way for the h10n8, h9n ... | 2021 | 34008327 |
| h7n9 influenza virus-like particle based on bevs protects chickens from lethal challenge with highly pathogenic h7n9 avian influenza virus. | h7n9 avian influenza virus poses a dual threat to both poultry industry and public health. therefore, it is highly urgent to develop an effective vaccine to reduce its pandemic potential. virus-like particles (vlp) represent an effective approach for pandemic vaccine development. in this study, a recombinant baculovirus co-expressing the ha, na and m1 genes of the h7n9 virus was constructed for generation of h7n9 vlp. single immunization of chickens with 15 μg of the vlp or the commercial whole ... | 2021 | 34004568 |
| egyptian fruit bats (rousettus aegyptiacus) were resistant to experimental inoculation with avian-origin influenza a virus of subtype h9n2, but are susceptible to experimental infection with bat-borne h9n2 virus. | influenza a viruses (iav) of subtype h9n2, endemic in world-wide poultry holdings, are reported to cause spill-over infections to pigs and humans and have also contributed substantially to recent reassortment-derived pre-pandemic zoonotic viruses of concern, such as the asian h7n9 viruses. recently, a h9n2 bat influenza a virus was found in egyptian fruit bats (rousettus aegyptiacus), raising the question of whether this bat species is a suitable host for iav. here, we studied the susceptibility ... | 2021 | 33919890 |
| genetic and biological properties of h7n9 avian influenza viruses detected after application of the h7n9 poultry vaccine in china. | the h7n9 avian influenza virus (aiv) that emerged in china have caused five waves of human infection. further human cases have been successfully prevented since september 2017 through the use of an h7n9 vaccine in poultry. however, the h7n9 aiv has not been eradicated from poultry in china, and its evolution remains largely unexplored. in this study, we isolated 19 h7n9 aivs during surveillance and diagnosis from february 2018 to december 2019, and genetic analysis showed that these viruses have ... | 2021 | 33905456 |
| development of an immunochromatographic strip for rapid detection of h7 subtype avian influenza viruses. | h7n9 avian influenza virus (aiv) including highly and low pathogenic viruses have been detected in china since 2013. h7n9 aiv has a high mortality rate after infection in humans, and most human cases have close contacted with poultry in the live poultry market. therefore, it is necessary to develop a rapid point-of-care testing (poct) technique for h7n9 aiv detection. | 2021 | 33827632 |
| identification of the dominant non-neutralizing epitope in the haemagglutinin of h7n9 avian influenza virus. | h7n9 avian influenza vaccines induce high levels of non-neutralizing (nonneu) antibodies against the haemagglutinin (ha). however, the antigenic epitopes underlying this particular antibody response are still undefined. in this study, a panel of 13 monoclonal antibodies (mabs) against the ha protein of h7n9 virus was generated and 12 of them had no hemagglutination inhibition and virus neutralizing activities. one linear epitope in the stalk (373-taa-375) recognized by three mabs and one conform ... | 2021 | 33819520 |
| genetic analysis of genotype g57 h9n2 avian influenza virus isolate a/chicken/tajikistan/2379/2018 recovered in central asia. | this paper presents genetic data on the full genome analysis of a/chicken/tajikistan/2379/2018 h9n2 influenza virus isolated in september 2018 from chicken pathological material received from poultry farms of the republic of tajikistan and subtyped as h9n2 by serological and molecular methods. according to the results of hemagglutinin gene sequencing, the amino acid sequence of the cleavage site was rssr/glf, which is typical for low-virulent avian influenza virus. phylogenetic analysis of the n ... | 2021 | 33740120 |
| reassortment with dominant chicken h9n2 influenza virus contributed to the fifth h7n9 virus human epidemic. | h9n2 avian influenza virus (aiv) is regarded as a principal donor of viral genes through reassortment to co-circulating influenza viruses that can result in zoonotic reassortants. whether h9n2 virus can maintain sustained evolutionary impact on such reassortants is unclear. since 2013, avian h7n9 virus had caused five sequential human epidemics in china; the fifth wave in 2016-2017 was by far the largest but the mechanistic explanation behind the scale of infection is not clear. here, we found t ... | 2021 | 33731452 |
| a live attenuated h9n2 avian influenza vaccine prevents the viral reassortment by exchanging the ha and ns1 packaging signals. | the h9n2 avian influenza virus is not only an important zoonotic pathogen, it can also easily recombine with other subtypes to generate novel reassortments, such as the h7n9 virus. although h9n2 live attenuated vaccines can provide good multiple immunities, including humoral, cellular, and mucosal immunity, the risk of reassortment between the vaccine strain and wild-type virus is still a concern. here, we successfully rescued an h9n2 live attenuated strain [rtx-ns1-128 (mut)] that can interdict ... | 2021 | 33613465 |
| g1-like m and pb2 genes are preferentially incorporated into h7n9 progeny virions during genetic reassortment. | genotype s h9n2 viruses have become predominant in poultry in china since 2010. these viruses frequently donate their whole internal gene segments to other emerging influenza a subtypes such as the novel h7n9, h5n6, and h10n8 viruses. we recently reported that the pb2 and m genes of the genotype s h9n2 virus, which are derived from the g1-like virus, enhance the fitness of h5nx and h7n9 avian influenza viruses in chickens and mice. however, whether the g1-like pb2 and m genes are preferentially ... | 2021 | 33588843 |
| a risk marker of tribasic hemagglutinin cleavage site in influenza a (h9n2) virus. | low pathogenic avian influenza a(h9n2) virus is endemic worldwide and continually recruit internal genes to generate human-infecting h5n1, h5n6, h7n9, and h10n8 influenza variants. here we show that hemagglutinin cleavage sites (hacs) of h9n2 viruses tended to mutate towards hydrophilic via evolutionary transition, and the tribasic hacs were found at high prevalence in asia and the middle east. our finding suggested that the tribasic h9n2 viruses increased the viral replication, stability, patho ... | 2021 | 33452423 |
| molecular characteristics of the h9n2 avian influenza viruses in live poultry markets in anhui province, china, 2013 to 2018. | h9n2 subtype avian influenza virus (aiv) has low-pathogenicity but causes respiratory symptoms and drop in egg production in chicken with long-term virus shedding, resulting in great economic losses due to high mortality related to secondary infection with other pathogens. in recent years, h9n2 viruses have been posing a threat to public health, causing human infection in china. compared to studies on other aiv subtypes, there are relatively few studies on the pathogenic mechanism of the h9n2 vi ... | 2021 | 33437876 |
| transcriptome profiles of highly pathogenic pure avian h7n9 virus-infected lungs of balb/c mice. | avian influenza a (h7n9) viruses emerged in china in 2013 and caused a zoonotic disease associated with a high case-fatality ratio of more than 30%. transcriptional profiles obtained using animal models reveal host responses to the disease, thereby providing insights into disease pathogenesis. therefore, we aimed to characterize the host responses of the h7n9 virus infected-mouse lungs in this study. first, we isolated an avian-originated h7n9 strain, which was shown to be highly pathogenic to b ... | 2020 | 33409298 |
| role of the hemagglutinin residue 227 in immunogenicity of h5 and h7 subtype avian influenza vaccines in chickens. | many h5 and h7 subtype avian influenza vaccines are poorly immunogenic in terms of inducing hemagglutination-inhibition (hi) antibody titers. residue 227 (h3 numbering) in the receptor binding site in the hemagglutinin (ha) is critical for the detectability of hi antibodies induced by h5 influenza vaccines. however, whether the effect of residue 227 on immunogenicity can be generalized in different subtypes is unclear. in this study, the impact of ha residue 227 on immunogenicity of h5n1, h5n6, ... | 2020 | 33347548 |
| establishing a multicolor flow cytometry to characterize cellular immune response in chickens following h7n9 avian influenza virus infection. | avian influenza virus (aiv) emerged and has continued to re-emerge, continuously posing great threats to animal and human health. the detection of hemagglutination inhibition (hi) or virus neutralization antibodies (na) is essential for assessing immune protection against aiv. however, the hi/na-independent immune protection is constantly observed in vaccines' development against h7n9 subtype aiv and other subtypes in chickens and mammals, necessitating the analysis of the cellular immune respon ... | 2020 | 33291218 |
| efficacy of a cap-dependent endonuclease inhibitor and neuraminidase inhibitors against h7n9 highly pathogenic avian influenza virus causing severe viral pneumonia in cynomolgus macaques. | h7n9 highly pathogenic avian influenza virus (hpaiv) infection in a human was first reported in 2017. a/duck/japan/aq-he29-22/2017 (h7n9) (dk/he29-22), found in imported duck meat at an airport in japan, possesses a hemagglutinin with a multibasic cleavage site, indicating high pathogenicity in chickens, as in the case of other h7 hpaivs. in the present study, we examined the pathogenicity of dk/he29-22 and the effectiveness of a cap-dependent endonuclease inhibitor (baloxavir) and neuraminidase ... | 2021 | 33257455 |
| dominant subtype switch in avian influenza viruses during 2016-2019 in china. | we have surveyed avian influenza virus (aiv) genomes from live poultry markets within china since 2014. here we present a total of 16,091 samples that were collected from may 2016 to february 2019 in 23 provinces and municipalities in china. we identify 2048 aiv-positive samples and perform next generation sequencing. aiv-positive rates (12.73%) from samples had decreased substantially since 2016, compared to that during 2014-2016 (26.90%). additionally, h9n2 has replaced h5n6 and h7n9 as the do ... | 2020 | 33219213 |
| molecular characteristics of h9n2 influenza viruses isolated from farmed raccoon dogs and arctic foxes in china. | in this study, eight h9n2 iavs were isolated from infected diseased, farmed raccoon dogs and arctic foxes. eight genes shared 98.6%-100% identity among the isolates possessing a psrssr/gl motif at the ha cleavage site, which is same as the motif of g1 and y280 lineages of h9n2 iavs. the phylogenetic analysis showed that the ha genes of the eight isolates clustered with y280-like viruses, whereas the na genes belonged to f/98-like sublineage. interestingly, the ns, np, pb2 and pa genes of the iso ... | 2020 | 33223121 |