The stamping-out strategy has been used to control highly pathogenic avian influenza viruses in many countries,driven by the belief that vaccination would not be successful against such viruses and fears that avian in...The stamping-out strategy has been used to control highly pathogenic avian influenza viruses in many countries,driven by the belief that vaccination would not be successful against such viruses and fears that avian influenza virus in vaccinated birds would evolve more rapidly and pose a greater risk to humans.In this review,we summarize the successes in controlling highly pathogenic avian influenza in China and make suggestions regarding the requirements for vaccine selection and effectiveness.In addition,we present evidence that vaccination of poultry not only eliminates human infection with avian influenza virus,but also significantly reduces and abolishes some harmful characteristics of avian influenza virus.展开更多
H7N9 subtype avian influenza virus poses a great challenge for poultry industry.Newcastle disease virus(NDV)-vectored H7N9 avian influenza vaccines(NDV_(vec)H7N9)are effective in disease control because they are prote...H7N9 subtype avian influenza virus poses a great challenge for poultry industry.Newcastle disease virus(NDV)-vectored H7N9 avian influenza vaccines(NDV_(vec)H7N9)are effective in disease control because they are protective and allow mass administration.Of note,these vaccines elicit undetectable H7N9-specific hemagglutination-inhibition(HI)but high IgG antibodies in chickens.However,the molecular basis and protective mechanism underlying this particular antibody immunity remain unclear.Herein,immunization with an NDV_(vec)H7N9 induced low anti-H7N9 HI and virus neutralization titers but high levels of hemagglutinin(HA)-binding IgG antibodies in chickens.Three residues(S150,G151 and S152)in HA of H7N9 virus were identified as the dominant epitopes recognized by the NDV_(vec)H7N9 immune serum.Passively transferred NDV_(vec)H7N9 immune serum conferred complete protection against H7N9 virus infection in chickens.The NDV_(vec)H7N9 immune serum can mediate a potent lysis of HA-expressing and H7N9 virus-infected cells and significantly suppress H7N9 virus infectivity.These activities of the serum were significantly impaired after heat-inactivation or treatment with complement inhibitor,suggesting the engagement of the complement system.Moreover,mutations in the 150-SGS-152 sites in HA resulted in significant reductions in cell lysis and virus neutralization mediated by the NDV_(vec)H7N9 immune serum,indicating the requirement of antibody-antigen binding for complement activity.Therefore,antibodies induced by the NDV_(vec)H7N9 can activate antibody-dependent complement-mediated lysis of H7N9 virus-infected cells and complement-mediated neutralization of H7N9 virus.Our findings unveiled a novel role of the complement in protection conferred by the NDV_(vec)H7N9,highlighting a potential benefit of engaging the complement system in H7N9 vaccine design.展开更多
BACKGROUND Most of the first symptoms of avian influenza are respiratory symptoms,and cases with occipital neuralgia as the first manifestation are rarely reported.CASE SUMMARY A middle-aged patient complaining of par...BACKGROUND Most of the first symptoms of avian influenza are respiratory symptoms,and cases with occipital neuralgia as the first manifestation are rarely reported.CASE SUMMARY A middle-aged patient complaining of paroxysmal pain behind the ear was admitted to our hospital.The patient’s condition changed rapidly,and high fever,unexpected respiratory failure,and multiple organ failure developed rapidly.The patient was diagnosed with H7N9 avian influenza based on etiology.CONCLUSION We believe that the etiology of occipital neuralgia is complex and could be the earliest manifestation of severe diseases.The possibility of an infectious disease should be considered when occipital neuralgia is accompanied by fever.Avian influenza is one of these causative agents.展开更多
This study investigated the humoral immunization of Astragalus polysaccharide (APS) against HgN2 avian influenza virus (H9N2 AIV) infection in chickens. The effects of APS treatment on H9N2 infection was evaluated...This study investigated the humoral immunization of Astragalus polysaccharide (APS) against HgN2 avian influenza virus (H9N2 AIV) infection in chickens. The effects of APS treatment on H9N2 infection was evaluated by an Mqq- [3(4, 5-dimethylthiazol-2-yl)-2, 3-diphenyl tetrazolium bromide] assay and analysis of MFIC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to H9N2 AIV wet enhanced in the first week after APS treatment. The results indicated that APS treatment reduces H9N2 AIV replication and promotes early humoral immune responses in young chickens.This study investigated the humoral immunization of Astragalus polysaccharide (APS) against HgN2 avian influenza virus (H9N2 AIV) infection in chickens. The effects of APS treatment on HgN2 infection was evaluated by an M]q- [3(4, 5-dimethylthiazol-2-yl)-2, 3-diphenyl tetrazolium bromide] assay and analysis of MHC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to PIgN2 AIV were enhanced in the first week after APS treatment. The results indicated that APS treatment reduces HgN2 AIV replication and promotes early humoral immune responses in young chickens.展开更多
A novel avian influenza A (H7N9) virus was discovered in February 2013 in China and has resulted in more than 100 comfirmed human infections including 26 fatal cases as of May 2, 2013. The situation raises many ur- ...A novel avian influenza A (H7N9) virus was discovered in February 2013 in China and has resulted in more than 100 comfirmed human infections including 26 fatal cases as of May 2, 2013. The situation raises many ur- gent questions and global public health concerns. In this study, epidemiologic characteristics of infected human cases in Jiangsu province were analyzed and risk assessment was undertaken based on the information available. Briefly, it is highly unlikely that a pandemic of human infection with avian influenza A (HTN9) virus will happen in Jiangsu Province in the near future. Iia the end, some measures are recommended to prevent the situation from becoming worse.展开更多
A Objective3 This study was to understand the genetic variation characters of the H9N2 subtype avian influenza virus isolate (A/Chicken/ Hebei/WD/98, abbreviated as WD98) by comparing with other reference strains. I...A Objective3 This study was to understand the genetic variation characters of the H9N2 subtype avian influenza virus isolate (A/Chicken/ Hebei/WD/98, abbreviated as WD98) by comparing with other reference strains. I-Method3 Eight complete genes were amplified by RT-PCR and sequenced. The homology and genetic evolution relationship were analyzed between these sequences and that of the seven reference strains. [Result] The whole genomic sequence of WD98 strain was 91.1% -95.8% homologous to that of seven reference strains tested. This isolate shared the highest homology (95.8%) to D/HK/Y280/97 and the lowest homology (91.1% ) to C/Pak/2/99. The HA cleavage site of the WD98 strain was R-S-S-R G, and the 226th amino acid at receptor-binding site was Gin. [ Condmion] WD98 strain belongs to mildly pathogenic avian in- fluenza virus and may not infect human. The genetic relationship is the closest between A/Chicken/Hebei/wD/98 and A/duck/HongKong/Y280/ 97, both of which belong to the sub-line of A/Chicken/Beijing/1/94 in Eurasian line. And A/Chicken/Hebei/WD/98 and A/Chicken/Beijing/1/94 are genetically distant within the same sub-line.展开更多
We have developed a rapid microarray-based assay for the reliable detection of H5, H7 and H9 subtypes of avian influenza virus (AIV). The strains used in the experiment were A/Goose/Guangdong/1/96 (H5N1), A/Africa...We have developed a rapid microarray-based assay for the reliable detection of H5, H7 and H9 subtypes of avian influenza virus (AIV). The strains used in the experiment were A/Goose/Guangdong/1/96 (H5N1), A/African starling/983/79 (H7N1) and A/Turkey/Wiscosin/1/66 (H9N2). The capture DNAs clones which encoding approximate 500-bp avian influenza virus gene fragments obtained by RT-PCR, were spotted on a slide-bound microarray. Cy5-labeled fluorescent cDNAs, which generated from virus RNA during reverse transcription were hybridized to these capture DNAs. These capture DNAs contained multiple fragments of the hemagglutinin and matrix protein genes of AIV respectively, for subtyping and typing AIV. The arrays were scanned to determine the probe binding sites. The hybridization pattern agreed approximately with the known grid location of each target. The results show that DNA microarray technology provides a useful diagnostic method for AIV.展开更多
Objective To survey avian influenza A viruses(AIVs) in the environment and explore the reasons for the surge in human H7 N9 cases.Methods A total of 1,045 samples were collected from routine surveillance on poultry-re...Objective To survey avian influenza A viruses(AIVs) in the environment and explore the reasons for the surge in human H7 N9 cases.Methods A total of 1,045 samples were collected from routine surveillance on poultry-related environments and 307 samples from human H7 N9 cases-exposed environments in Henan from 2016 to2017. The nucleic acids of influenza A(Flu A), H5, H7, and H9 subtypes were detected by real-time polymerase chain reaction.Results A total of 27 H7 N9 cases were confirmed in Henan from 2016 to 2017, 24 had a history of live poultry exposure, and 15 had H7 N9 virus detected in the related live poultry markets(LPMs). About 96%(264/275) Flu A positive-environmental samples were from LPMs. H9 was the main AIV subtype(10.05%) from routine surveillance sites with only 1 H7-positive sample, whereas 21.17% samples were H7-positive in H7 N9 cases-exposed environments. Samples from H7 N9 cases-exposed LPMs(47.56%)had much higher AIVs positive rates than those from routine surveillance sites(12.34%). The H7+H9 combination of mixed infection was 78.18%(43/55) of H7-positive samples and 41.34%(43/104) of H9-positive samples.Conclusion The contamination status of AIVs in poultry-related environments is closely associated with the incidence of human infection caused by AIVs. Therefore, systematic surveillance of AIVs in LPMs in China is essential for the detection of novel reassortant viruses and their potential for interspecies transmission.展开更多
The contamination status of H5 avian influenza viruses and distribution of subtypes of H5N1 and H5N6 in poultry-related environment of Hubei areas were investigated.Urban and rural live poultry markets,poultry farms,i...The contamination status of H5 avian influenza viruses and distribution of subtypes of H5N1 and H5N6 in poultry-related environment of Hubei areas were investigated.Urban and rural live poultry markets,poultry farms,intensive livestock farms and other monitoring types of 103 counties in 17 cities were selected in Hubei.Wiping samples from cage surface,wiping samples from chopping board,fecal specimens and other environmental samples were collected and tested by real-time RT-PCR using primers and probes of influenza A,avian influenza of H5,N1 and N6 from December 2017 to March 2018.The avian influenza virus positive rate was compared among different monitoring sites,samples,time and regions.Totally,7132 environmental samples were collected in 1634 monitoring points with a positive rate of 2.24%.The positive rate of H5 avian influenza virus was the highest in urban and rural live poultry markets(3.44%,x^2=61.329,P<0.05)in 6 monitoring sites and wiping samples from chopping board(5.46%,x^2=67.072,P<0.05)in 6 sample types.H5N6 avian influenza viruses were detected more in eastern than western Hubei,and H5N6 avian influenza viruses were detected only in Xiangyang city of western Hubei.There were important high-risk places of human infection with H5 avian influenza virus in urban and rural live poultry markets and the poultry slaughtering plants.H5N6 has been the predominant subtype of H5 avian influenza viruses in the eastern and western Hubei and H5N6 avian influenza viruses were still present in a few areas of Hubei.Outbreaks of human H5N1 and H5N6 avian influenza remain at risk in Hubei province.展开更多
The DNA vaccine pCIHA5 encoding hemagglutinin can protect SPF chicken against lethal H5N1 avian influenza virus challenge. The more characters about its protection efficacity were studied. The protective rates in 10...The DNA vaccine pCIHA5 encoding hemagglutinin can protect SPF chicken against lethal H5N1 avian influenza virus challenge. The more characters about its protection efficacity were studied. The protective rates in 10, 40, 70, 100 and 150 μg groups immunized with pCIHA5 were 12.5 (1/8), 58.3 (7/12), 72.7 (8/11), 50.0 (6/12) and 66.7% (8/12), respectively. The protective rates in 5, 20, 35 and 50 μg groups were 145.5 (5/11), 58.3 (7/12), 58.3 (7/12) and 91.7% (11/12), respectively. The 70, 100 and 5 μg groups have virus shedding of 1/8, 2/6 and 1/5. Though the inactived oil-emulsion vaccine has high HI antibody titers and 100% protective rate, the AGP antibody could be detected after vaccination. Results show that the pCIHA5 is fit to boost by intramuscular injection. This would be useful to the study on gene engineering vaccine of avian influenza virus.展开更多
HA Gene of H9N2. sub-type avian influenza virus from three strains in different times was amplified, purified and then sequenced. The results of its sequence analysis showed that the whole length of the amplified HA G...HA Gene of H9N2. sub-type avian influenza virus from three strains in different times was amplified, purified and then sequenced. The results of its sequence analysis showed that the whole length of the amplified HA Gene was 1 683 bp, encoding 560 amino acids. The amino acid sequence of three virulent strains at cleavage site was R-S-S-R, which was low-pathogenicity strain. According to the amino acid sequence of the isolated strains, there were 7 potential glycosylation sites, and the receptor-binding site was the specific sequence of the avian-derived influenza virus. Amino acids on the left edge of receptor-binding site were all NGQQG, while amino acids on the right edge of receptor-binding site were GTSKA. From the comparative sequence analysis of HA Gene from some referenced strains, the results indicated that nucleotide and amino acid homology between isolated strains and referenced strains was higher. Evolutionary tree analysis showed that three strains were all Eurasian species, and there was a close relationship with the representative strains of A / duck / Hong Kong/Y280/97.展开更多
Live poultry markets(LPMs) are crucial places for human infection of influenza A(H7N9 virus).In Yangtze River Delta,LPMs were closed after the outbreak of human infection with avian influenza A(H7N9) virus,and t...Live poultry markets(LPMs) are crucial places for human infection of influenza A(H7N9 virus).In Yangtze River Delta,LPMs were closed after the outbreak of human infection with avian influenza A(H7N9) virus,and then reopened when no case was found.Our purpose was to quantify the effect of LPMs' operations in this region on the transmission of influenza A(H7N9) virus.We obtained information about dates of symptom onset and locations for all human influenza A(H7N9) cases reported from Shanghai,Jiangsu and Zhejiang provinces by May 31,2014,and acquired dates of closures and reopening of LPMs from official media.A two-phase Bayesian model was fitted by Markov Chain Monte Carlo methods to process the spatial and temporal influence of human cases.A total of 235 cases of influenza A(H7N9) were confirmed in Shanghai,Jiangsu and Zhejiang by May 31,2014.Using these data,our analysis showed that,after LPM closures,the influenza A(H7N9) outbreak disappeared within two weeks in Shanghai,one week in Jiangsu,and one week in Zhejiang,respectively.Local authorities reopened LPMs when there was no outbreak of influenza A(H7N9),which did not lead to reemergence of human influenza A(H7N9).LPM closures were effective in controlling the H7N9 outbreak.Reopening of LPM in summer did not increase the risk of human infection with H7N9.Our findings showed that LPMs should be closed immediately in areas where the H7N9 virus is confirmed in LPM.When there is no outbreak of H7N9 virus,LPMs can be reopened to satisfy the Chinese traditional culture of buying live poultry.In the long term,local authorities should take a cautious attitude in permanent LPM closure.展开更多
Objective In March 2012, an H7N7 subtype avian influenza virus (AIV) named A/wild goose/Dongting/PC0360/2022 (H7N7) (DT/PC0360) was recovered from a wild goose in East Dongting Lake. We performed whole-genome se...Objective In March 2012, an H7N7 subtype avian influenza virus (AIV) named A/wild goose/Dongting/PC0360/2022 (H7N7) (DT/PC0360) was recovered from a wild goose in East Dongting Lake. We performed whole-genome sequencing of the isolate, and analyzed the phylogenetic and molecular characterization. Methods RNA was extracted from environment samples (including fecal samples from wild bird or domestic ducks, and water samples) for detecting the presence of Influenza A Virus targeting Matrix gene, using realtime RT-PCR assay. The positive samples were performed virus isolation with embryonated eggs. The subtype of the isolates were identified by RT-PCR assay with the HI-HI6 and N1-N9 primer set. The whole-genome sequencing of isolates were performed. Phylogenetic and molecular characterizations of the eight genes of the isolates were analyzed. Results Our results suggested that all the eight gene segments of DT/PC0360 belonged to the Eurasian gene pool, and the HA gene were belonged to distinct sublineage with H7N9 AIV which caused outbreaks in China's Mainland in 2013. The hemagglutinin cleavage site of HA of DT/PC0360 showed characterization of low pathogenic avian influenza virus. Conclusion Strengthening the surveillance of AlVs of wild waterfowl and poultry in this region is vita for our knowledge of the ecology and mechanism of transmission to prevent an influenza pandemic.展开更多
H9 s ubtype avian influenza virus(AIV) and infectious bronchitis virus(IBV) are major pathogens circulating in poultry and have resulted in great economic losses due to respiratory disease and reduced egg producti...H9 s ubtype avian influenza virus(AIV) and infectious bronchitis virus(IBV) are major pathogens circulating in poultry and have resulted in great economic losses due to respiratory disease and reduced egg production. As similar symptoms are elicited by the two pathogens, it is difficult for their differential diagnosis. So far, no reverse transcription-polymerase chain reaction(RT-PCR) assay has been found to differentiate between H9 AIV and IBV in one reaction. Therefore, developing a sensitive and specific method is of importance to simultaneously detect and differentiate H9 AIV and IBV. In this study, a duplex RT-PCR(d RT-PCR) was established. Two primer sets target the hemagglutinin(HA) gene of H9 AIV and the nucleocapsid(N) gene of IBV, respectively. Spec ific PCR products were obtained from all tested H9 AIVs and IBVs belonging to the major clades circulating in China, but not from AIVs of other subtypes or other infectious avian viruses. The sensitivity of the d RT-PCR assay corresponding to H9 AIV, IBV and mixture of H9 AIV and IBV were at a concentration of 1×10^1, 1.5×10^1 and 1.5×10^1 50% egg infective doses(EID_(50)) m L^–1, respectively. The concordance rates between the d RT-PCR and virus isolation were 99.1 and 98.2%, respectively, for detection of samples from H9N2 AIV or IBV infected chickens, while the concordance rate was 99.1% for detection of samples from H9N2 AIV and IBV co-infected chickens. Thus, the d RT-PCR assay reported herein is specific and sensitive, and suitable for the differential diagnosis of clinical infections and survei llance of H9 AIVs and IBVs.展开更多
In the past decade,there has been extensive global surveillance for highly pathogenic avian influenza(HPAI)infection in both animals and humans,however,few studies on epidemiology of avian influenza in Democratic Peo...In the past decade,there has been extensive global surveillance for highly pathogenic avian influenza(HPAI)infection in both animals and humans,however,few studies on epidemiology of avian influenza in Democratic People’s Republic of Korea(DPRK)were published.During the period 2013–2014,HPAI H5N1 viruses were detected with outbreaks in domestic poultry in DPRK.Phylogenetic analysis revealed that the hemagglutinin gene of all samples belonged to clade 2.3.2.1c with high homology.The HPAI H5N1 virus found in ducks at the Tudan Duck Farm in 2013 was might introduced by migratory birds and then led to the outbreaks on neighboring chicken farms in 2014.These data provide direct evidence for the transmission of avian influenza viruses from wild birds to waterfowl to terrestrial birds.Therefore,the monitoring and control of influenza virus in ducks must be given top priority,which are essential components to prevent and control HPAI.展开更多
Objective In China, 24 cases of human infection with highly pathogenic avian influenza(HPAI) H5 N6 virus have been confirmed since the first confirmed case in 2014. Therefore, we developed and assessed two H5 N6 candi...Objective In China, 24 cases of human infection with highly pathogenic avian influenza(HPAI) H5 N6 virus have been confirmed since the first confirmed case in 2014. Therefore, we developed and assessed two H5 N6 candidate vaccine viruses(CVVs).Methods In accordance with the World Health Organization(WHO) recommendations, we constructed two reassortant viruses using reverse genetics(RG) technology to match the two different epidemic H5 N6 viruses. We performed complete genome sequencing to determine the genetic stability. We assessed the growth ability of the studied viruses in MDCK cells and conducted a hemagglutination inhibition assay to analyze their antigenicity. Pathogenicity attenuation was also evaluated in vitro and in vivo.Results The results showed that no mutations occurred in hemagglutinin or neuraminidase, and both CVVs retained their original antigenicity. The replication capacity of the two CVVs reached a level similar to that of A/Puerto Rico/8/34 in MDCK cells. The two CVVs showed low pathogenicity in vitro and in vivo, which are in line with the WHO requirements for CVVs.Conclusion We obtained two genetically stable CVVs of HPAI H5N6 with high growth characteristics,which may aid in our preparedness for a potential H5N6 pandemic.展开更多
The highly pathogenic influenza A virus subtype H5N1 spread throughout Asia since 2003, reached to Europe in 2005, and the Middle East, as well as Africa and caused a global concern for a potential pandemic threat las...The highly pathogenic influenza A virus subtype H5N1 spread throughout Asia since 2003, reached to Europe in 2005, and the Middle East, as well as Africa and caused a global concern for a potential pandemic threat last decade. A Clade 2.3.2 H5N1 virus became dominate in the Qinghai Lake region in 2009 with sporadic mammal cases of infection and transferred to Russia and Europe through wild migratory birds. Currently, HPAI H5N1 of clades 2.3.4, 2.3.2, and 7 are the dominant co-circulating H5N1 viruses in poultry in Asia. 2.3.2 Clade is dominant in wild birds through the world whereas there is no evident data about Clade 7 circulation in wild birds. We detected HPAI H5N1 virus of Clade 7.1 in Qinghai Lake, that closely related to Shanxi-like and Vietnam viruses co-circulating in poultry. This is the first report of Clade 7.1 H5N1 in wild birds. Based on phylogenetic analyses, the virus can be originated from Clade 7.1 virus gene pool that spread in Vietnam and Chinese poultry and could spread with migratory birds to Qinghai Lake. The Qinghai Lake continues to be significant hotspot for H5N1 surveillance since the regular outbreaks occurred there in wild birds and mammals. Based on these facts and findings, the related researchers should pay more attention to the Qinghai Lake basin as significant hotspot for H5N1 avian influenza surveillance since the regular H5N1 outbreaks occurred there in wild birds with sporadic mammal cases of infection.展开更多
A recombinant fowlpox virus co-expressing Haemagglutinin (HA) and Neuraminidase (NA)named as rFPV-HA-NA was produced by HA and NA gene of A/Goose/Guangdong/3/96(H5N1)isolate of avian influenza virus recombined into th...A recombinant fowlpox virus co-expressing Haemagglutinin (HA) and Neuraminidase (NA)named as rFPV-HA-NA was produced by HA and NA gene of A/Goose/Guangdong/3/96(H5N1)isolate of avian influenza virus recombined into the genome of fowlpox virus. In thisstudy, to evaluate its ability of protecting chickens against challenge with a lethaldose of highly pathogenic isolates of avian influenza virus, eight-week-old specific-pathogenic-free (SPF) chickens were vaccinated with recombinant virus or the wildtypefowlpox virus by wing-web puncture. After challenge 4 weeks with 10 LD50 highly pathogenicavian influenza virus H5N1 and H7N1 isolate, all chickens vaccinated with recombinantvirus were protected, while the chickens vaccinated with the wildtype fowlpox virus orunvaccinated controls experienced 100% mortality respectively following challenge. Thiscomplete protection was accompanied by the high levels of specific antibody response tothe respective components of the recombinant virus.展开更多
In this study, in situ hybridization (ISH) was developed to detect avian influenza'virus (AIV) in Madin-Darby canine kidney (MDCK) cells and formalin-fixed, paraffin-embedded chicken tissues. A cDNA probe corre...In this study, in situ hybridization (ISH) was developed to detect avian influenza'virus (AIV) in Madin-Darby canine kidney (MDCK) cells and formalin-fixed, paraffin-embedded chicken tissues. A cDNA probe corresponding to a region of AIV nucleoprotein (NP) gene was synthesized and labeled with digoxigenin. Probe specificity was determined by AIV infected MDCK cells in vitro and the results showed that strong cytoplasmic staining was only detected in AIV-infected cells. Various tissues were collected from 12 h to 35 days post-infection (PI) following inoculation with the H9N2 subtype A1V. AIV was localized in the epithelial cells of the duodenum and cartilage of the throat and trachea at 12 h PI. Tissues from uninfected chickens were negative. The finding of this study indicated ISH was a sensitive and specific technique to detect and localize AIV as well as to study AIV pathogenesis.展开更多
基金This work was supported by the National Key Research andDevelopment Programof China(2021YFD1800200 and2021YFC2301700).
文摘The stamping-out strategy has been used to control highly pathogenic avian influenza viruses in many countries,driven by the belief that vaccination would not be successful against such viruses and fears that avian influenza virus in vaccinated birds would evolve more rapidly and pose a greater risk to humans.In this review,we summarize the successes in controlling highly pathogenic avian influenza in China and make suggestions regarding the requirements for vaccine selection and effectiveness.In addition,we present evidence that vaccination of poultry not only eliminates human infection with avian influenza virus,but also significantly reduces and abolishes some harmful characteristics of avian influenza virus.
基金supported by the earmarked fund for China Agriculture Research System(CARS-40)the Key Research and Development Project of Yangzhou(Modern Agriculture),China(YZ2022052)the‘‘High-end Talent Support Program’’of Yangzhou University,China。
文摘H7N9 subtype avian influenza virus poses a great challenge for poultry industry.Newcastle disease virus(NDV)-vectored H7N9 avian influenza vaccines(NDV_(vec)H7N9)are effective in disease control because they are protective and allow mass administration.Of note,these vaccines elicit undetectable H7N9-specific hemagglutination-inhibition(HI)but high IgG antibodies in chickens.However,the molecular basis and protective mechanism underlying this particular antibody immunity remain unclear.Herein,immunization with an NDV_(vec)H7N9 induced low anti-H7N9 HI and virus neutralization titers but high levels of hemagglutinin(HA)-binding IgG antibodies in chickens.Three residues(S150,G151 and S152)in HA of H7N9 virus were identified as the dominant epitopes recognized by the NDV_(vec)H7N9 immune serum.Passively transferred NDV_(vec)H7N9 immune serum conferred complete protection against H7N9 virus infection in chickens.The NDV_(vec)H7N9 immune serum can mediate a potent lysis of HA-expressing and H7N9 virus-infected cells and significantly suppress H7N9 virus infectivity.These activities of the serum were significantly impaired after heat-inactivation or treatment with complement inhibitor,suggesting the engagement of the complement system.Moreover,mutations in the 150-SGS-152 sites in HA resulted in significant reductions in cell lysis and virus neutralization mediated by the NDV_(vec)H7N9 immune serum,indicating the requirement of antibody-antigen binding for complement activity.Therefore,antibodies induced by the NDV_(vec)H7N9 can activate antibody-dependent complement-mediated lysis of H7N9 virus-infected cells and complement-mediated neutralization of H7N9 virus.Our findings unveiled a novel role of the complement in protection conferred by the NDV_(vec)H7N9,highlighting a potential benefit of engaging the complement system in H7N9 vaccine design.
文摘BACKGROUND Most of the first symptoms of avian influenza are respiratory symptoms,and cases with occipital neuralgia as the first manifestation are rarely reported.CASE SUMMARY A middle-aged patient complaining of paroxysmal pain behind the ear was admitted to our hospital.The patient’s condition changed rapidly,and high fever,unexpected respiratory failure,and multiple organ failure developed rapidly.The patient was diagnosed with H7N9 avian influenza based on etiology.CONCLUSION We believe that the etiology of occipital neuralgia is complex and could be the earliest manifestation of severe diseases.The possibility of an infectious disease should be considered when occipital neuralgia is accompanied by fever.Avian influenza is one of these causative agents.
基金supported by funds provided by South China Agricultural University and Guangzhou work team project(No 2011A020102009)
文摘This study investigated the humoral immunization of Astragalus polysaccharide (APS) against HgN2 avian influenza virus (H9N2 AIV) infection in chickens. The effects of APS treatment on H9N2 infection was evaluated by an Mqq- [3(4, 5-dimethylthiazol-2-yl)-2, 3-diphenyl tetrazolium bromide] assay and analysis of MFIC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to H9N2 AIV wet enhanced in the first week after APS treatment. The results indicated that APS treatment reduces H9N2 AIV replication and promotes early humoral immune responses in young chickens.This study investigated the humoral immunization of Astragalus polysaccharide (APS) against HgN2 avian influenza virus (H9N2 AIV) infection in chickens. The effects of APS treatment on HgN2 infection was evaluated by an M]q- [3(4, 5-dimethylthiazol-2-yl)-2, 3-diphenyl tetrazolium bromide] assay and analysis of MHC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to PIgN2 AIV were enhanced in the first week after APS treatment. The results indicated that APS treatment reduces HgN2 AIV replication and promotes early humoral immune responses in young chickens.
基金supported by the Jiangsu Province Health Development Project with Science and Education (No.ZX201109 and RC2011085)the Research Projects of Jiangsu Preventive Medicine (No.YZ201020)
文摘A novel avian influenza A (H7N9) virus was discovered in February 2013 in China and has resulted in more than 100 comfirmed human infections including 26 fatal cases as of May 2, 2013. The situation raises many ur- gent questions and global public health concerns. In this study, epidemiologic characteristics of infected human cases in Jiangsu province were analyzed and risk assessment was undertaken based on the information available. Briefly, it is highly unlikely that a pandemic of human infection with avian influenza A (HTN9) virus will happen in Jiangsu Province in the near future. Iia the end, some measures are recommended to prevent the situation from becoming worse.
基金supported by subproject of National Program on Key Basic Research Project (973 Program )(2005CB523001)
文摘A Objective3 This study was to understand the genetic variation characters of the H9N2 subtype avian influenza virus isolate (A/Chicken/ Hebei/WD/98, abbreviated as WD98) by comparing with other reference strains. I-Method3 Eight complete genes were amplified by RT-PCR and sequenced. The homology and genetic evolution relationship were analyzed between these sequences and that of the seven reference strains. [Result] The whole genomic sequence of WD98 strain was 91.1% -95.8% homologous to that of seven reference strains tested. This isolate shared the highest homology (95.8%) to D/HK/Y280/97 and the lowest homology (91.1% ) to C/Pak/2/99. The HA cleavage site of the WD98 strain was R-S-S-R G, and the 226th amino acid at receptor-binding site was Gin. [ Condmion] WD98 strain belongs to mildly pathogenic avian in- fluenza virus and may not infect human. The genetic relationship is the closest between A/Chicken/Hebei/wD/98 and A/duck/HongKong/Y280/ 97, both of which belong to the sub-line of A/Chicken/Beijing/1/94 in Eurasian line. And A/Chicken/Hebei/WD/98 and A/Chicken/Beijing/1/94 are genetically distant within the same sub-line.
基金Chinese National S&T“1Oth Five-Year"Plan (2004BA519A23) the National Natural Science Foundation ofChina (30200201 , 30440009).
文摘We have developed a rapid microarray-based assay for the reliable detection of H5, H7 and H9 subtypes of avian influenza virus (AIV). The strains used in the experiment were A/Goose/Guangdong/1/96 (H5N1), A/African starling/983/79 (H7N1) and A/Turkey/Wiscosin/1/66 (H9N2). The capture DNAs clones which encoding approximate 500-bp avian influenza virus gene fragments obtained by RT-PCR, were spotted on a slide-bound microarray. Cy5-labeled fluorescent cDNAs, which generated from virus RNA during reverse transcription were hybridized to these capture DNAs. These capture DNAs contained multiple fragments of the hemagglutinin and matrix protein genes of AIV respectively, for subtyping and typing AIV. The arrays were scanned to determine the probe binding sites. The hybridization pattern agreed approximately with the known grid location of each target. The results show that DNA microarray technology provides a useful diagnostic method for AIV.
基金supported by Henan Department of Science and Technology Project [182102310235]Henan Medical Science and Technology Research Project [201702269]Henan Natural Science Foundation [182300410384]
文摘Objective To survey avian influenza A viruses(AIVs) in the environment and explore the reasons for the surge in human H7 N9 cases.Methods A total of 1,045 samples were collected from routine surveillance on poultry-related environments and 307 samples from human H7 N9 cases-exposed environments in Henan from 2016 to2017. The nucleic acids of influenza A(Flu A), H5, H7, and H9 subtypes were detected by real-time polymerase chain reaction.Results A total of 27 H7 N9 cases were confirmed in Henan from 2016 to 2017, 24 had a history of live poultry exposure, and 15 had H7 N9 virus detected in the related live poultry markets(LPMs). About 96%(264/275) Flu A positive-environmental samples were from LPMs. H9 was the main AIV subtype(10.05%) from routine surveillance sites with only 1 H7-positive sample, whereas 21.17% samples were H7-positive in H7 N9 cases-exposed environments. Samples from H7 N9 cases-exposed LPMs(47.56%)had much higher AIVs positive rates than those from routine surveillance sites(12.34%). The H7+H9 combination of mixed infection was 78.18%(43/55) of H7-positive samples and 41.34%(43/104) of H9-positive samples.Conclusion The contamination status of AIVs in poultry-related environments is closely associated with the incidence of human infection caused by AIVs. Therefore, systematic surveillance of AIVs in LPMs in China is essential for the detection of novel reassortant viruses and their potential for interspecies transmission.
基金the Natural Science Foundation of Hubei Province,China(No.2017CFB710).
文摘The contamination status of H5 avian influenza viruses and distribution of subtypes of H5N1 and H5N6 in poultry-related environment of Hubei areas were investigated.Urban and rural live poultry markets,poultry farms,intensive livestock farms and other monitoring types of 103 counties in 17 cities were selected in Hubei.Wiping samples from cage surface,wiping samples from chopping board,fecal specimens and other environmental samples were collected and tested by real-time RT-PCR using primers and probes of influenza A,avian influenza of H5,N1 and N6 from December 2017 to March 2018.The avian influenza virus positive rate was compared among different monitoring sites,samples,time and regions.Totally,7132 environmental samples were collected in 1634 monitoring points with a positive rate of 2.24%.The positive rate of H5 avian influenza virus was the highest in urban and rural live poultry markets(3.44%,x^2=61.329,P<0.05)in 6 monitoring sites and wiping samples from chopping board(5.46%,x^2=67.072,P<0.05)in 6 sample types.H5N6 avian influenza viruses were detected more in eastern than western Hubei,and H5N6 avian influenza viruses were detected only in Xiangyang city of western Hubei.There were important high-risk places of human infection with H5 avian influenza virus in urban and rural live poultry markets and the poultry slaughtering plants.H5N6 has been the predominant subtype of H5 avian influenza viruses in the eastern and western Hubei and H5N6 avian influenza viruses were still present in a few areas of Hubei.Outbreaks of human H5N1 and H5N6 avian influenza remain at risk in Hubei province.
文摘The DNA vaccine pCIHA5 encoding hemagglutinin can protect SPF chicken against lethal H5N1 avian influenza virus challenge. The more characters about its protection efficacity were studied. The protective rates in 10, 40, 70, 100 and 150 μg groups immunized with pCIHA5 were 12.5 (1/8), 58.3 (7/12), 72.7 (8/11), 50.0 (6/12) and 66.7% (8/12), respectively. The protective rates in 5, 20, 35 and 50 μg groups were 145.5 (5/11), 58.3 (7/12), 58.3 (7/12) and 91.7% (11/12), respectively. The 70, 100 and 5 μg groups have virus shedding of 1/8, 2/6 and 1/5. Though the inactived oil-emulsion vaccine has high HI antibody titers and 100% protective rate, the AGP antibody could be detected after vaccination. Results show that the pCIHA5 is fit to boost by intramuscular injection. This would be useful to the study on gene engineering vaccine of avian influenza virus.
文摘HA Gene of H9N2. sub-type avian influenza virus from three strains in different times was amplified, purified and then sequenced. The results of its sequence analysis showed that the whole length of the amplified HA Gene was 1 683 bp, encoding 560 amino acids. The amino acid sequence of three virulent strains at cleavage site was R-S-S-R, which was low-pathogenicity strain. According to the amino acid sequence of the isolated strains, there were 7 potential glycosylation sites, and the receptor-binding site was the specific sequence of the avian-derived influenza virus. Amino acids on the left edge of receptor-binding site were all NGQQG, while amino acids on the right edge of receptor-binding site were GTSKA. From the comparative sequence analysis of HA Gene from some referenced strains, the results indicated that nucleotide and amino acid homology between isolated strains and referenced strains was higher. Evolutionary tree analysis showed that three strains were all Eurasian species, and there was a close relationship with the representative strains of A / duck / Hong Kong/Y280/97.
文摘Live poultry markets(LPMs) are crucial places for human infection of influenza A(H7N9 virus).In Yangtze River Delta,LPMs were closed after the outbreak of human infection with avian influenza A(H7N9) virus,and then reopened when no case was found.Our purpose was to quantify the effect of LPMs' operations in this region on the transmission of influenza A(H7N9) virus.We obtained information about dates of symptom onset and locations for all human influenza A(H7N9) cases reported from Shanghai,Jiangsu and Zhejiang provinces by May 31,2014,and acquired dates of closures and reopening of LPMs from official media.A two-phase Bayesian model was fitted by Markov Chain Monte Carlo methods to process the spatial and temporal influence of human cases.A total of 235 cases of influenza A(H7N9) were confirmed in Shanghai,Jiangsu and Zhejiang by May 31,2014.Using these data,our analysis showed that,after LPM closures,the influenza A(H7N9) outbreak disappeared within two weeks in Shanghai,one week in Jiangsu,and one week in Zhejiang,respectively.Local authorities reopened LPMs when there was no outbreak of influenza A(H7N9),which did not lead to reemergence of human influenza A(H7N9).LPM closures were effective in controlling the H7N9 outbreak.Reopening of LPM in summer did not increase the risk of human infection with H7N9.Our findings showed that LPMs should be closed immediately in areas where the H7N9 virus is confirmed in LPM.When there is no outbreak of H7N9 virus,LPMs can be reopened to satisfy the Chinese traditional culture of buying live poultry.In the long term,local authorities should take a cautious attitude in permanent LPM closure.
文摘Objective In March 2012, an H7N7 subtype avian influenza virus (AIV) named A/wild goose/Dongting/PC0360/2022 (H7N7) (DT/PC0360) was recovered from a wild goose in East Dongting Lake. We performed whole-genome sequencing of the isolate, and analyzed the phylogenetic and molecular characterization. Methods RNA was extracted from environment samples (including fecal samples from wild bird or domestic ducks, and water samples) for detecting the presence of Influenza A Virus targeting Matrix gene, using realtime RT-PCR assay. The positive samples were performed virus isolation with embryonated eggs. The subtype of the isolates were identified by RT-PCR assay with the HI-HI6 and N1-N9 primer set. The whole-genome sequencing of isolates were performed. Phylogenetic and molecular characterizations of the eight genes of the isolates were analyzed. Results Our results suggested that all the eight gene segments of DT/PC0360 belonged to the Eurasian gene pool, and the HA gene were belonged to distinct sublineage with H7N9 AIV which caused outbreaks in China's Mainland in 2013. The hemagglutinin cleavage site of HA of DT/PC0360 showed characterization of low pathogenic avian influenza virus. Conclusion Strengthening the surveillance of AlVs of wild waterfowl and poultry in this region is vita for our knowledge of the ecology and mechanism of transmission to prevent an influenza pandemic.
基金supported by the National High-Tech R&D Program of China(2012AA101303)
文摘H9 s ubtype avian influenza virus(AIV) and infectious bronchitis virus(IBV) are major pathogens circulating in poultry and have resulted in great economic losses due to respiratory disease and reduced egg production. As similar symptoms are elicited by the two pathogens, it is difficult for their differential diagnosis. So far, no reverse transcription-polymerase chain reaction(RT-PCR) assay has been found to differentiate between H9 AIV and IBV in one reaction. Therefore, developing a sensitive and specific method is of importance to simultaneously detect and differentiate H9 AIV and IBV. In this study, a duplex RT-PCR(d RT-PCR) was established. Two primer sets target the hemagglutinin(HA) gene of H9 AIV and the nucleocapsid(N) gene of IBV, respectively. Spec ific PCR products were obtained from all tested H9 AIVs and IBVs belonging to the major clades circulating in China, but not from AIVs of other subtypes or other infectious avian viruses. The sensitivity of the d RT-PCR assay corresponding to H9 AIV, IBV and mixture of H9 AIV and IBV were at a concentration of 1×10^1, 1.5×10^1 and 1.5×10^1 50% egg infective doses(EID_(50)) m L^–1, respectively. The concordance rates between the d RT-PCR and virus isolation were 99.1 and 98.2%, respectively, for detection of samples from H9N2 AIV or IBV infected chickens, while the concordance rate was 99.1% for detection of samples from H9N2 AIV and IBV co-infected chickens. Thus, the d RT-PCR assay reported herein is specific and sensitive, and suitable for the differential diagnosis of clinical infections and survei llance of H9 AIVs and IBVs.
基金supported by the China Agriculture Research System of MOF and MARA(CARS-41)。
文摘In the past decade,there has been extensive global surveillance for highly pathogenic avian influenza(HPAI)infection in both animals and humans,however,few studies on epidemiology of avian influenza in Democratic People’s Republic of Korea(DPRK)were published.During the period 2013–2014,HPAI H5N1 viruses were detected with outbreaks in domestic poultry in DPRK.Phylogenetic analysis revealed that the hemagglutinin gene of all samples belonged to clade 2.3.2.1c with high homology.The HPAI H5N1 virus found in ducks at the Tudan Duck Farm in 2013 was might introduced by migratory birds and then led to the outbreaks on neighboring chicken farms in 2014.These data provide direct evidence for the transmission of avian influenza viruses from wild birds to waterfowl to terrestrial birds.Therefore,the monitoring and control of influenza virus in ducks must be given top priority,which are essential components to prevent and control HPAI.
基金This study was supported by the National Major Science and Technology Project for Control and Prevention of Major Infectious Diseases in China[No.2018ZX10711001,2018ZX10305409-004-002]Emergency Prevention and Control Project of Ministry of Science and Technology of China[No.10600100000015001206].
文摘Objective In China, 24 cases of human infection with highly pathogenic avian influenza(HPAI) H5 N6 virus have been confirmed since the first confirmed case in 2014. Therefore, we developed and assessed two H5 N6 candidate vaccine viruses(CVVs).Methods In accordance with the World Health Organization(WHO) recommendations, we constructed two reassortant viruses using reverse genetics(RG) technology to match the two different epidemic H5 N6 viruses. We performed complete genome sequencing to determine the genetic stability. We assessed the growth ability of the studied viruses in MDCK cells and conducted a hemagglutination inhibition assay to analyze their antigenicity. Pathogenicity attenuation was also evaluated in vitro and in vivo.Results The results showed that no mutations occurred in hemagglutinin or neuraminidase, and both CVVs retained their original antigenicity. The replication capacity of the two CVVs reached a level similar to that of A/Puerto Rico/8/34 in MDCK cells. The two CVVs showed low pathogenicity in vitro and in vivo, which are in line with the WHO requirements for CVVs.Conclusion We obtained two genetically stable CVVs of HPAI H5N6 with high growth characteristics,which may aid in our preparedness for a potential H5N6 pandemic.
文摘The highly pathogenic influenza A virus subtype H5N1 spread throughout Asia since 2003, reached to Europe in 2005, and the Middle East, as well as Africa and caused a global concern for a potential pandemic threat last decade. A Clade 2.3.2 H5N1 virus became dominate in the Qinghai Lake region in 2009 with sporadic mammal cases of infection and transferred to Russia and Europe through wild migratory birds. Currently, HPAI H5N1 of clades 2.3.4, 2.3.2, and 7 are the dominant co-circulating H5N1 viruses in poultry in Asia. 2.3.2 Clade is dominant in wild birds through the world whereas there is no evident data about Clade 7 circulation in wild birds. We detected HPAI H5N1 virus of Clade 7.1 in Qinghai Lake, that closely related to Shanxi-like and Vietnam viruses co-circulating in poultry. This is the first report of Clade 7.1 H5N1 in wild birds. Based on phylogenetic analyses, the virus can be originated from Clade 7.1 virus gene pool that spread in Vietnam and Chinese poultry and could spread with migratory birds to Qinghai Lake. The Qinghai Lake continues to be significant hotspot for H5N1 surveillance since the regular outbreaks occurred there in wild birds and mammals. Based on these facts and findings, the related researchers should pay more attention to the Qinghai Lake basin as significant hotspot for H5N1 avian influenza surveillance since the regular H5N1 outbreaks occurred there in wild birds with sporadic mammal cases of infection.
文摘A recombinant fowlpox virus co-expressing Haemagglutinin (HA) and Neuraminidase (NA)named as rFPV-HA-NA was produced by HA and NA gene of A/Goose/Guangdong/3/96(H5N1)isolate of avian influenza virus recombined into the genome of fowlpox virus. In thisstudy, to evaluate its ability of protecting chickens against challenge with a lethaldose of highly pathogenic isolates of avian influenza virus, eight-week-old specific-pathogenic-free (SPF) chickens were vaccinated with recombinant virus or the wildtypefowlpox virus by wing-web puncture. After challenge 4 weeks with 10 LD50 highly pathogenicavian influenza virus H5N1 and H7N1 isolate, all chickens vaccinated with recombinantvirus were protected, while the chickens vaccinated with the wildtype fowlpox virus orunvaccinated controls experienced 100% mortality respectively following challenge. Thiscomplete protection was accompanied by the high levels of specific antibody response tothe respective components of the recombinant virus.
文摘In this study, in situ hybridization (ISH) was developed to detect avian influenza'virus (AIV) in Madin-Darby canine kidney (MDCK) cells and formalin-fixed, paraffin-embedded chicken tissues. A cDNA probe corresponding to a region of AIV nucleoprotein (NP) gene was synthesized and labeled with digoxigenin. Probe specificity was determined by AIV infected MDCK cells in vitro and the results showed that strong cytoplasmic staining was only detected in AIV-infected cells. Various tissues were collected from 12 h to 35 days post-infection (PI) following inoculation with the H9N2 subtype A1V. AIV was localized in the epithelial cells of the duodenum and cartilage of the throat and trachea at 12 h PI. Tissues from uninfected chickens were negative. The finding of this study indicated ISH was a sensitive and specific technique to detect and localize AIV as well as to study AIV pathogenesis.