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Sample records for human h5n1 isolates

  1. Characterization of H5N1 influenza viruses isolated from humans in vitro

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    Kameoka Masanori

    2010-06-01

    Full Text Available Abstract Since December 1997, highly pathogenic avian influenza A H5N1viruses have swept through poultry populations across Asian countries and been transmitted into African and European countries. We characterized 6 avian influenza H5N1 viruses isolated from humans in 2004 in Thailand. A highly pathogenic (HP KAN353 strain showed faster replication and higher virulence in embryonated eggs compared to other strains, especially compared to the low pathogenic (LP SP83 strain. HP KAN353 also showed strong cytopathogenicity compared to SP83 in Madin-Darby canine kidney cells. Interestingly, LP SP83 induced smaller plaques compared to other strains, especially HP KAN353. PB2 amino acid 627E may contribute to low virulence, whereas either PB2 amino acid 627 K or the combination of 627E/701N seems to be associated with high virulence. The in vitro assays used in this study may provide the basis for assessing the pathogenesis of influenza H5N1 viruses in vivo.

  2. Novel Polymerase Gene Mutations for Human Adaptation in Clinical Isolates of Avian H5N1 Influenza Viruses.

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    Arai, Yasuha; Kawashita, Norihito; Daidoji, Tomo; Ibrahim, Madiha S; El-Gendy, Emad M; Takagi, Tatsuya; Takahashi, Kazuo; Suzuki, Yasuo; Ikuta, Kazuyoshi; Nakaya, Takaaki; Shioda, Tatsuo; Watanabe, Yohei

    2016-04-01

    A major determinant in the change of the avian influenza virus host range to humans is the E627K substitution in the PB2 polymerase protein. However, the polymerase activity of avian influenza viruses with a single PB2-E627K mutation is still lower than that of seasonal human influenza viruses, implying that avian viruses require polymerase mutations in addition to PB2-627K for human adaptation. Here, we used a database search of H5N1 clade 2.2.1 virus sequences with the PB2-627K mutation to identify other polymerase adaptation mutations that have been selected in infected patients. Several of the mutations identified acted cooperatively with PB2-627K to increase viral growth in human airway epithelial cells and mouse lungs. These mutations were in multiple domains of the polymerase complex other than the PB2-627 domain, highlighting a complicated avian-to-human adaptation pathway of avian influenza viruses. Thus, H5N1 viruses could rapidly acquire multiple polymerase mutations that function cooperatively with PB2-627K in infected patients for optimal human adaptation.

  3. Influenza H5N1 Virus of Birds Surrounding H5N1 Human Cases Have Specific Characteristics on the Matrix Protein

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    NI LUH PUTU INDI DHARMAYANTI

    2011-06-01

    Full Text Available The H5N1 influenza virus in Indonesia has caused more than 100 people died due to the virus infections. Cases in humans were mostly due to the virus spread from the infected birds. This study characterized molecularly the H5N1 virus from birds around the H5N1 infection cases in humans in Indonesia. Result from this study revealed that in several cases, waterfowl species could become the source of H5N1 infections in human. We found that the one of six viruses used in this study probably was a first antigenic shift virus in Indonesia. This study shows that the AI viruses isolated from birds around humans infected by H5N1 virus has specific characteristics namely the presence of several amino acid substitutions especially on the M1 and M2 proteins. The substitutions are similar in most of H5N1 human cases in Indonesia.

  4. Isolation and characterization of highly pathogenic avian influenza virus subtype H5N1 from donkeys

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    Abdel-Ghany Ahmad E

    2010-04-01

    Full Text Available Abstract Background The highly pathogenic H5N1 is a major avian pathogen that crosses species barriers and seriously affects humans as well as some mammals. It mutates in an intensified manner and is considered a potential candidate for the possible next pandemic with all the catastrophic consequences. Methods Nasal swabs were collected from donkeys suffered from respiratory distress. The virus was isolated from the pooled nasal swabs in specific pathogen free embryonated chicken eggs (SPF-ECE. Reverse transcriptase polymerase chain reaction (RT-PCR and sequencing of both haemagglutingin and neuraminidase were performed. H5 seroconversion was screened using haemagglutination inhibition (HI assay on 105 donkey serum samples. Results We demonstrated that H5N1 jumped from poultry to another mammalian host; donkeys. Phylogenetic analysis showed that the virus clustered within the lineage of H5N1 from Egypt, closely related to 2009 isolates. It harboured few genetic changes compared to the closely related viruses from avian and humans. The neuraminidase lacks oseltamivir resistant mutations. Interestingly, HI screening for antibodies to H5 haemagglutinins in donkeys revealed high exposure rate. Conclusions These findings extend the host range of the H5N1 influenza virus, possess implications for influenza virus epidemiology and highlight the need for the systematic surveillance of H5N1 in animals in the vicinity of backyard poultry units especially in endemic areas.

  5. Isolation of avian influenza H5N1 virus from vaccinated commercial layer flock in Egypt

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    El-Zoghby Elham F

    2012-11-01

    Full Text Available Abstract Background Uninterrupted transmission of highly pathogenic avian influenza virus (HPAIV H5N1 of clade 2.2.1 in Egypt since 2006 resulted in establishment of two main genetic clusters. The 2.2.1/C group where all recent human and majority of backyard origin viruses clustered together, meanwhile the majority of viruses derived from vaccinated poultry in commercial farms grouped in 2.2.1.1 clade. Findings In the present investigation, an HPAIV H5N1 was isolated from twenty weeks old layers chickens that were vaccinated with a homologous H5N1 vaccine at 1, 7 and 16 weeks old. At twenty weeks of age, birds showed cyanosis of comb and wattle, decrease in egg production and up to 27% mortality. Examined serum samples showed low antibody titer in HI test (Log2 3.2± 4.2. The hemagglutinin (HA and neuraminidase (NA genes of the isolated virus were closely related to viruses in 2.2.1/C group isolated from poultry in live bird market (LBM and backyards or from infected people. Conspicuous mutations in the HA and NA genes including a deletion within the receptor binding domain in the HA globular head region were observed. Conclusions Despite repeated vaccination of layer chickens using a homologous H5N1 vaccine, infection with HPAIV H5N1 resulted in significant morbidity and mortality. In endemic countries like Egypt, rigorous control measures including enforcement of biosecurity, culling of infected birds and constant update of vaccine virus strains are highly required to prevent circulation of HPAIV H5N1 between backyard birds, commercial poultry, LBM and humans.

  6. Mx1 gene protects mice against the highly lethal human H5N1 influenza virus.

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    Salomon, Rachelle; Staeheli, Peter; Kochs, Georg; Yen, Hui-Ling; Franks, John; Rehg, Jerold E; Webster, Robert G; Hoffmann, Erich

    2007-10-01

    We investigated the importance of the host Mx1 gene in protection against highly pathogenic H5N1 avian influenza virus. Mice expressing the Mx1 gene survived infection with the lethal human H5N1 isolate A/Vietnam/1203/04 and with reassortants combining its genes with those of the non-lethal virus A/chicken/Vietnam/C58/04, while all Mx1-/- mice succumbed. Mx1-expressing mice showed lower organ virus titers, fewer lesions, and less pulmonary inflammation. Our data support the hypothesis that Mx1 expression protects mice against the high pathogenicity of H5N1 virus through inhibition of viral polymerase activity ultimately resulting in reduced viral growth and spread. Drugs that mimic this mechanism may be protective in humans.

  7. Genetic drift evolution under vaccination pressure among H5N1 Egyptian isolates

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    Afifi Manal A

    2011-06-01

    Full Text Available Background The highly pathogenic H5N1 is a major avian pathogen that intensively affects the poultry industry in Egypt even in spite of the adoption of vaccination strategy. Antigenic drift is among the strategies the influenza virus uses to escape the immune system that might develop due to the pressure of extensive vaccination. H5N1 mutates in an intensified manner and is considered a potential candidate for the possible next pandemic with all the catastrophic consequences such an eventuality will entail. Methods H5N1 was isolated from the pooled organ samples of four different affected flocks in specific pathogen free embryonated chicken eggs (SPF-ECE. A reverse transcriptase polymerase chain reaction (RT-PCR was performed to the haemagglutingin and neuraminidase. Sequencing of the full length haemagglutingin was performed. Sequence analyses of the isolated strains were performed and compared to all available H5N1 from Egyptian human and avian strains in the flu database. Changes in the different amino acid that may be related to virus virulence, receptor affinity and epitope configuration were assigned and matched with all available Egyptian strains in the flu database. Results One out of the four strains was found to be related to the B2 Egyptian lineage, 2 were related to A1 lineage and the 4th was related to A2 lineage. Comparing data obtained from the current study by other available Egyptian H5N1 sequences remarkably demonstrates that amino acid changes in the immune escape variants are remarkably restricted to a limited number of locations on the HA molecule during antigenic drift. Molecular diversity in the HA gene, in relevance to different epitopes, were not found to follow a regular trend, suggesting abrupt cumulative sequence mutations. However a number of amino acids were found to be subjected to high mutation pressure. Conclusion The current data provides a comprehensive view of HA gene evolution among H5N1 subtype viruses in

  8. Evolution and adaptation of hemagglutinin gene of human H5N1 influenza virus.

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    Wei, Kaifa; Chen, Yanfeng; Chen, Juan; Wu, Lingjuan; Xie, Daoxin

    2012-06-01

    The H5N1 HPAI virus has brought heavy loss to poultry industry. Although, there exists limited human-to-human transmission, it poses potential serious risks to public health. HA is responsible for receptor-binding and membrane-fusion and contains the host receptor-binding sites and major epitopes for neutralizing antibodies. To investigate molecular adaption of HPAI H5N1 viruses, we performed a phylogenetic analysis of HA sequences with 240 HPAI virus strains isolated from human. The topology of the tree reveals overall clustering of strains in four major clusters based on geographic location, and shows antigenic diversity of HA of human H5N1 isolates co-circulating in Asia, Africa, and Europe. The four clusters possess distinct features within the cleavage site and glycosylation sites, respectively. We identified six sites apparently evolving under positive selection, five of which persist in the population. Three positively selected sites are found to be located either within or flanking the receptor-binding sites, suggesting that selection at these sites may increase the affinity to human-type receptor. Furthermore, some sites are also associated with glycosylation and antigenic changes. In addition, two sites are found to be selected differentially in the two clusters. The analyses provide us deep insight into the adaptive evolution of human H5N1 viruses, show us several candidate mutations that could cause a pandemic, and suggest that efficiency measures should be taken to deal with potential risks.

  9. Pathogenicity of human high pathogenic H5N1 virus with different plaque property

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    Yong-qiang LI

    2011-06-01

    Full Text Available Objective To determine the pathogenicity of human high pathogenic H5N1 virus with different plaque property,and provide a new train of thought and basis for research on crossing species-genus transmission of avian influenza virus.Methods Variants with different plaque property(larger-and smaller-plaque variant were isolated from A/Beijing/01/03(H5N1(BJ01 by the plaque purification.Mice were inoculated intranasally(i.n. with each kind of isolated variant and monitored for 14 days to record and calculate the body weight change and the survival rate.The difference in pathogenicity of isolated variants was estimated with proper principle of statistics.Results The plaques of original strain of BJ01 virus were heterogeneous with various size and shape.Larger-plaque variants(L1 and L2 and smaller-plaque variants(S1,S2 and S3 were isolated separately.The pathogenicity was higher in S1 and S2 variants than in S3,L1 and L2 variants,and that of L2 variant was the lowest.Variants forming different plaques were heterogeneous in pathogenicity,and those forming same plaques were also heterogeneous in pathogenicity.Conclusion There is no linear correlation between the pathogenicity of variants and the size of plaque they formed.The variants with different pathogenicity could be isolated from the same H5N1 virus strain by plaque purification.These results would provide a basis for vaccine development and the studies on molecular mechanism of H5N1 virus.

  10. Subclinical avian influenza A(H5N1) virus infection in human, Vietnam.

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    Le, Mai Quynh; Horby, Peter; Fox, Annette; Nguyen, Hien Tran; Le Nguyen, Hang Khanh; Hoang, Phuong Mai Vu; Nguyen, Khanh Cong; de Jong, Menno D; Jeeninga, Rienk E; Rogier van Doorn, H; Farrar, Jeremy; Wertheim, Heiman F L

    2013-10-01

    Laboratory-confirmed cases of subclinical infection with avian influenza A(H5N1) virus in humans are rare, and the true number of these cases is unknown. We describe the identification of a laboratory-confirmed subclinical case in a woman during an influenza A(H5N1) contact investigation in northern Vietnam.

  11. Human avian influenza A (H5N1) virus infection in China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Highly pathogenic influenza A (H5N1) virus causes a widespread poultry deaths worldwide. The first human H5N1 infected case was reported in Hong Kong Special Administrative Region of China in 1997. Since then, the virus re-emerged in 2003 and continues to infect people worldwide. Currently, over 400 human infections have been reported in more than 15 countries and mortality rate is greater than 60%. H5N1 viruses still pose a potential pandemic threat in the future because of the continuing global spread and evolution. Here, we summarize the epidemiological, clinical and virological characteristics of human H5N1 infection in China monitored and identified by our national surveillance systems.

  12. PHYLOGENETIC AND ANTIGENIC STRUCTURE OF AVIAN INFLUENZA VIRUS OF H5N1 SUBTYPE ISOLATED FROM WATERFOWLS

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    R Susanti

    2008-09-01

    Full Text Available A study was carried (1 to analyze the phylogenetic relationship of fragment hemaglutinin (HA geneof avian influenza viruses (AIV subtype H5N1 isolated from apparently healthy backyard waterfowls inWest Java with representative of animal and human isolates from Indonesia and some countries in Asia;(2 to find out cross-reactivity of those viruses with a standard Indonesian strain. Nucleotide sequences ofHA gene of AIV H5N1 from backyard waterfowls along with other H5N1 isolates of Indonesian and Asianorigin were aligned using with ClustalW of MEGA 3.1 program. Estimation of genetic distance and theconstruction phylogenetic tree were conducted by Neighbor Joining method and calculation of distancematrix using Kimura 2-parameter. Antigenic analysis was conducted using hemagglutination inhibition(HI test. Result of phylogenetic analysis indicated that all viruses from backyard waterfowls form threedistinct sublineages. One lineage was located in Indonesia cluster and two lineages in Asia cluster. In thephylogenetic analysis, it was concluded that multiple introductions of AIV H5N1 to Indonesia have occurred.Six AI H5N1 viruses from backyard waterfowls (IPB1-RS to IPB6-RS appeared to be different ancestorsthose isolated previously in Indonesia. Cross-antigenic analysis showed that nine viruses isolates used inthis study were antigenically different to Legok 2003 chicken strain of AIV H5N1. The HI titer of anti-Legok 2003 antibody with all newly isolated viruses is up to 6 log lower then the HI titer using homologstrain.

  13. Insights into Human Astrocyte Response to H5N1 Infection by Microarray Analysis

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    Xian Lin

    2015-05-01

    Full Text Available Influenza virus infects not only the respiratory system but also the central nervous system (CNS, leading to influenza-associated encephalopathy and encephalitis. Astrocytes are essential for brain homeostasis and neuronal function. These cells can also be infected by influenza virus. However, genome-wide changes in response to influenza viral infection in astrocytes have not been defined. In this study, we performed gene profiling of human astrocytes in response to H5N1. Innate immune and pro-inflammatory responses were strongly activated at 24 h post-infection (hpi. Antiviral genes, as well as several cytokines and chemokines, including CXCL9, CXCL10, and CXCL11, were robustly induced. Phosphorylation of p65 and p38 can be activated by viral infection, suggesting their potential critical roles in H5N1-induced pro-inflammatory response. Moreover, H5N1 infection significantly upregulated the gene expressions related to the neuroactive ligand-receptor interaction pathway at 24 hpi, such as MC2R, CHRNG, P2RY13, GABRA1, and HRH2, which participant in synaptic transmission and may take part in CNS disorders induced by H5N1 infection. Targeting key components of innate immune response and the neuroactive ligand-receptor interaction pathway may provide a strategy to control H5N1-induced encephalopathy and encephalitis. This research can contribute to the understanding of H5N1 pathogenesis in astrocytes.

  14. Is avian influenza virus A(H5N1) a real threat to human health?

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    Amendola, A; Ranghiero, A; Zanetti, A; Pariani, E

    2011-09-01

    The A(H5N1) influenza remains a disease of birds with a significant species barrier: in the presence of some tens million cases of infection in poultry--with a wide geographical spread--, only a few hundreds cases have occurred in humans. To date, human cases have been reported in 15 countries--mainly in Asia--and all were related to the onset of outbreaks in poultry. A peak of H5N1 human cases was recorded in 2006, then decreasing in subsequent years. Despite this trend, the H5N1 virus still represents a possible threat to human health, considering that more than half of human cases of H5N1 have been fatal. Moreover, despite the drop in the number of cases, the risk of a novel pandemic cannot be excluded, since H5N1 continues to circulate in poultry in countries with elevated human population density and where monitoring systems are not fully appropriate. In addition, there is a major global concern about the potential occurrence of a reassortment between the 2009 pandemic H1N1 and the highly pathogenic H5N1 influenza viruses following a co-infection in a susceptible host. Therefore, the implementation of appropriate surveillance and containment measures is crucial in order to minimize such risk. In conclusion, H5N1 avian influenza is still a rare disease in humans but its clinical severe outcome requires a careful monitoring of the virus's ability to evolve and to trigger a new pandemic.

  15. Intersubtype Reassortments of H5N1 Highly Pathogenic Avian Influenza Viruses Isolated from Quail.

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    Nguyen, Tinh Huu; Than, Van Thai; Thanh, Hien Dang; Hung, Vu-Khac; Nguyen, Duc Tan; Kim, Wonyong

    2016-01-01

    H5N1 highly pathogenic avian influenza (HPAI) viruses are considered a threat to national animal industries, causing production losses and high mortality in domestic poultry. In recent years, quail has become a popular terrestrial poultry species raised for production of meat and eggs in Asia. In this study, to better understand the roles of quail in H5N1 viral evolution, two H5N1-positive samples, designated A/quail/Vietnam/CVVI-49/2010 (CVVI-49/2010) and A/quail/Vietnam/CVVI-50/2014 (CVVI-50/2014), were isolated from quail during H5N1 outbreaks in Vietnam, and their whole genome were analyzed. The phylogenetic analysis reveals new evolutionary variation in the worldwide H5N1 viruses. The quail HA genes were clustered into clades 1.1.1 (CVVI-49/2010) and clade 2.3.2.1c (CVVI-50/2014), which may have evolved from viruses circulating from chickens and/or ducks in Cambodia, mainland of China, Taiwan, Indonesia, and South Korea in recent years. Interestingly, the M2 gene of the CVVI-49/2010 strain contained amino acid substitutions at position 26L-I and 31S-N that are related to amantadine-resistance. In particular, the CVVI-50/2014 strain revealed evidence of multiple intersubtype reassortment events between virus clades 2.3.2.1c, 2.3.2.1b, and 2.3.2.1a. Data from this study supports the possible role of quail as an important intermediate host in avian influenza virus evolution. Therefore, additional surveillance is needed to monitor these HPAI viruses both serologically and virologically in quail.

  16. Genetic dynamic analysis of the H5N1 Avian influenza virus NS1 gene isolated in Bali

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    Arief Mulyono

    2013-05-01

    Full Text Available AbstrakLatar belakang:Virus Avian Influenza H5N1 diperkirakan terus bermutasi, yang berpotensi meningkatkan kapasitas untuk melompati barier spesies, dan dapat menular secara mudah antar manusia. Penelitian ini bertujuan untuk menganalisis dinamika genetik gen NS1 dan mengetahui adanya marka virulensi pada sekuen gen NS1 VAI H5N1 ayam asal Bali.Metode: Metode yang digunakan dalam penelitian ini adalah isolasi RNA, amplifikasi gen NS1 dengan Reverse Transcriptase Polymerase Chain Reaction (RT-PCR, elektroforesis dan sequencing. Data sekuen isolat virus Avian influenza H5N1 asal Bali tersebut selanjutnya dibandingkan dengan multiple aligment dengan isolat asal Indonesia lainnya dari berbagai hospes yang diakses melalui GenBank tahun 2005-2007, dan pembuatan pohon filogenetik.Hasil:Keempat isolat uji mengalami substitusi P42S dan delesi 5 asam amino pada posisi 80-84 yang mengakibatkan potensi peningkatan virulensi virus, namun tidak dijumpai adanya substitusi D92E, F103L dan M106I. Analisis filogenetik menunjukkan keempat isolat uji mempunyai kekerabatan genetik lebih dekat dengan isolat asal kucing dan manusia. Dibandingkan dengan isolat Bali tahun 2005 isolat uji mengalami peningkatan substitusi nukleotida dan asam amino.Kesimpulan:Isolat VAI H5N1 asal Bali mengalami dinamika genetik dan ditemukan marker virulensi pada sekuen gen NS1. (Health Science Indones 2012;2:xx-xxKata kunci: avian influenza, H5N1, NS1Abstract Background:H5N1 Avian Influenza virus is expected to continue to mutate, potentially increasing the capacity to jump the species barrier, and can be easily transmitted between humans. This study aimed to analyze the genetic dynamics of the NS1 gene and to recognize markers of virulence in VAI H5N1 NS1 gene sequences from Balinese poultry.Methods:The method used was isolation of RNA, NS1 gene amplification  by  Reverse  Transcriptase Polymerase Chain Reaction (RT-PCR, electrophoresis and sequencing. Data sequence Avian influenza H5

  17. Seasonal patterns in human A (H5N1 virus infection: analysis of global cases.

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    Maya B Mathur

    Full Text Available Human cases of highly pathogenic avian influenza (HPAI A (H5N1 have high mortality. Despite abundant data on seasonal patterns in influenza epidemics, it is unknown whether similar patterns exist for human HPAI H5N1 cases worldwide. Such knowledge could help decrease avian-to-human transmission through increased prevention and control activities during peak periods.We performed a systematic search of published human HPAI H5N1 cases to date, collecting month, year, country, season, hemisphere, and climate data. We used negative binomial regression to predict changes in case incidence as a function of season. To investigate hemisphere as a potential moderator, we used AIC and the likelihood-ratio test to compare the season-only model to nested models including a main effect or interaction with hemisphere. Finally, we visually assessed replication of seasonal patterns across climate groups based on the Köppen-Geiger climate classification.We identified 617 human cases (611 with complete seasonal data occurring in 15 countries in Southeast Asia, Africa, and the Middle East. Case occurrence was much higher in winter (n = 285, p = 0.03 than summer (n = 64, and the winter peak occurred across diverse climate groups. There was no significant interaction between hemisphere and season.Across diverse climates, HPAI H5N1 virus infection in humans increases significantly in winter. This is consistent with increased poultry outbreaks and HPAI H5N1 virus transmission during cold and dry conditions. Prioritizing prevention and control activities among poultry and focusing public health messaging to reduce poultry exposures during winter months may help to reduce zoonotic transmission of HPAI H5N1 virus in resource-limited settings.

  18. Molecular characterization of highly pathogenic H5N1 avian influenza A viruses isolated from raccoon dogs in China.

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    Xian Qi

    Full Text Available BACKGROUND: The highly pathogenic avian influenza H5N1 virus can infect a variety of animals and continually poses a threat to animal and human health. While many genotypes of H5N1 virus can be found in chicken, few are associated with the infection of mammals. Characterization of the genotypes of viral strains in animal populations is important to understand the distribution of different viral strains in various hosts. This also facilitates the surveillance and detection of possible emergence of highly pathogenic strains of specific genotypes from unknown hosts or hosts that have not been previously reported to carry these genotypes. METHODOLOGY/PRINCIPAL FINDINGS: Two H5N1 isolates were obtained from lung samples of two raccoon dogs that had died from respiratory disease in China. Pathogenicity experiments showed that the isolates were highly pathogenic to chicken. To characterize the genotypes of these viruses, their genomic sequences were determined and analyzed. The genetic contents of these isolates are virtually identical and they may come from the same progenitor virus. Phylogenetic analysis indicated that the isolates were genetically closely related to genotype V H5N1 virus, which was first isolated in China in 2003, and were distinct from the dominant virus genotypes (e.g. genotype Z of recent years. The isolates also contain a multibasic amino acid motif at their HA cleavage sites and have an E residue at position 627 of the PB2 protein similar to the previously-identified avian viruses. CONCLUSIONS/SIGNIFICANCE: This is the first report that genotype V H5N1 virus is found to be associated with a mammalian host. Our results strongly suggest that genotype V H5N1 virus has the ability to cross species barriers to infect mammalian animals. These findings further highlight the risk that avian influenza H5N1 virus poses to mammals and humans, which may be infected by specific genotypes that are not known to infect these hosts.

  19. A review on human influenza A H5N1 infections in Hong Kong

    Institute of Scientific and Technical Information of China (English)

    CHAN Paul K S

    2009-01-01

    Avian influenza A H5N1 remains the most threatening virus that may cause another devastating pan-demic in the foreseeable future, In 1997, Hong Kong was the first place to detect human infections due to this virus originated from birds. The experience and lessons learnt provide important information for controlling further outbreaks caused by avian influenza viruses.

  20. A review on human influenza A H5N1 infections in Hong Kong

    Institute of Scientific and Technical Information of China (English)

    CHAN; Paul; K; S

    2009-01-01

    Avian influenza A H5N1 remains the most threatening virus that may cause another devastating pandemic in the foreseeable future. In 1997, Hong Kong was the first place to detect human infections due to this virus originated from birds. The experience and lessons learnt provide important information for controlling further outbreaks caused by avian influenza viruses.

  1. Serologic cross-reactivity among humans and birds infected with highly pathogenic avian influenza A subtype H5N1 viruses in China.

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    Li, Zheng; Ma, Chi; Liu, Zhonghua; He, Wei

    2011-03-30

    To study immunogenicity and serologic cross-reactivity of hemagglutinins (HAs) among humans and birds infected with highly pathogenic avian influenza (HPAI) H5N1, four representative H5N1 HA genes from humans and birds infected with distinct genetic clusters of H5N1 viruses in China were cloned, and several H5N1 infected human serum and H5N1 positive bird serum samples were used. Recombinant HA proteins were generated for ELISA assays and pseudotype viruses containing HAs were produced for neutralization assays and hemagglutination inhibition (HI) tests. We found significant differences among clades compared to species in binding, neutralization and HI activity of H5N1 strains isolated from birds. While significant differences were observed among species in H5N1 isolated from humans, investigation of H5N1 infected human and avian sera provided evidence that the pressure from nAb may be a driving force for positive selection. Therefore, improved anti-viral nAb therapies could block avian influenza transmission in humans.

  2. Proinflammatory cytokine responses induced by influenza A (H5N1 viruses in primary human alveolar and bronchial epithelial cells

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    Poon LLM

    2005-11-01

    Full Text Available Abstract Background Fatal human respiratory disease associated with influenza A subtype H5N1 has been documented in Hong Kong, and more recently in Vietnam, Thailand and Cambodia. We previously demonstrated that patients with H5N1 disease had unusually high serum levels of IP-10 (interferon-gamma-inducible protein-10. Furthermore, when compared with human influenza virus subtype H1N1, the H5N1 viruses in 1997 (A/Hong Kong/483/97 (H5N1/97 were more potent inducers of pro-inflammatory cytokines (e.g. tumor necrosis factor-a and chemokines (e.g. IP-10 from primary human macrophages in vitro, which suggests that cytokines dysregulation may play a role in pathogenesis of H5N1 disease. Since respiratory epithelial cells are the primary target cell for replication of influenza viruses, it is pertinent to investigate the cytokine induction profile of H5N1 viruses in these cells. Methods We used quantitative RT-PCR and ELISA to compare the profile of cytokine and chemokine gene expression induced by H5N1 viruses A/HK/483/97 (H5N1/97, A/Vietnam/1194/04 and A/Vietnam/3046/04 (both H5N1/04 with that of human H1N1 virus in human primary alveolar and bronchial epithelial cells in vitro. Results We demonstrated that in comparison to human H1N1 viruses, H5N1/97 and H5N1/04 viruses were more potent inducers of IP-10, interferon beta, RANTES (regulated on activation, normal T cell expressed and secreted and interleukin 6 (IL-6 in primary human alveolar and bronchial epithelial cells in vitro. Recent H5N1 viruses from Vietnam (H5N1/04 appeared to be even more potent at inducing IP-10 than H5N1/97 virus. Conclusion The H5N1/97 and H5N1/04 subtype influenza A viruses are more potent inducers of proinflammatory cytokines and chemokines in primary human respiratory epithelial cells than subtype H1N1 virus. We suggest that this hyper-induction of cytokines may be relevant to the pathogenesis of human H5N1 disease.

  3. Full-genome analysis of avian influenza A(H5N1) virus from a human, North America, 2013.

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    Pabbaraju, Kanti; Tellier, Raymond; Wong, Sallene; Li, Yan; Bastien, Nathalie; Tang, Julian W; Drews, Steven J; Jang, Yunho; Davis, C Todd; Fonseca, Kevin; Tipples, Graham A

    2014-05-01

    Full-genome analysis was conducted on the first isolate of a highly pathogenic avian influenza A(H5N1) virus from a human in North America. The virus has a hemagglutinin gene of clade 2.3.2.1c and is a reassortant with an H9N2 subtype lineage polymerase basic 2 gene. No mutations conferring resistance to adamantanes or neuraminidase inhibitors were found.

  4. The antigenic property of the H5N1 avian influenza viruses isolated in central China

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    Zou Wei

    2012-08-01

    Full Text Available Abstract Background Three influenza pandemics outbroke in the last century accompanied the viral antigen shift and drift, resulting in the change of antigenic property and the low cross protective ability of the existed antibody to the newly emerged pandemic virus, and eventually the death of millions of people. The antigenic characterizations of the viruses isolated in central China in 2004 and 2006–2007 were investigated in the present study. Results Hemagglutinin inhibition assay and neutralization assay displayed differential antigenic characteristics of the viruses isolated in central China in two periods (2004 and 2006–2007. HA genes of the viruses mainly located in two branches in phylogeny analysis. 53 mutations of the deduced amino acids of the HA genes were divided into 4 patterns. Mutations in pattern 2 and 3 showed the main difference between viruses isolated in 2004 and 2006–2007. Meanwhile, most amino acids in pattern 2 and 3 located in the globular head of the HA protein, and some of the mutations evenly distributed at the epitope sites. Conclusions The study demonstrated that a major antigenic drift had occurred in the viruses isolated in central China. And monitoring the antigenic property should be the priority in preventing the potential pandemic of H5N1 avian influenza virus.

  5. Molecular analysis of Hemagglutinin Gen of Highly Pathogenic Avian Influenza of H5N1 Subtype Isolated from Waterfowls

    National Research Council Canada - National Science Library

    R Susanti; Retno D Soejoedono; I Gusti Ngurah K Mahardika; I Wayan T Wibawan; Maggy T Suhartono

    2008-01-01

    Avian influenza viruses (AIV) subtype H5N1 isolated from waterfowls in West Java pose the known characteristic of highly pathogenic strains, with polybasic amino acid sequence of cleavage site QRERRRKKR and QRESRRKKR...

  6. Highly pathogenic avian influenza (H5N1: pathways of exposure at the animal-human interface, a systematic review.

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    Maria D Van Kerkhove

    Full Text Available BACKGROUND: The threat posed by highly pathogenic avian influenza A H5N1 viruses to humans remains significant, given the continued occurrence of sporadic human cases (499 human cases in 15 countries with a high case fatality rate (approximately 60%, the endemicity in poultry populations in several countries, and the potential for reassortment with the newly emerging 2009 H1N1 pandemic strain. Therefore, we review risk factors for H5N1 infection in humans. METHODS AND FINDINGS: Several epidemiologic studies have evaluated the risk factors associated with increased risk of H5N1 infection among humans who were exposed to H5N1 viruses. Our review shows that most H5N1 cases are attributed to exposure to sick poultry. Most cases are sporadic, while occasional limited human-to-human transmission occurs. The most commonly identified factors associated with H5N1 virus infection included exposure through contact with infected blood or bodily fluids of infected poultry via food preparation practices; touching and caring for infected poultry; [corrected] exposure to H5N1 via swimming or bathing in potentially virus laden ponds; and exposure to H5N1 at live bird markets. CONCLUSIONS: Research has demonstrated that despite frequent and widespread contact with poultry, transmission of the H5N1 virus from poultry to humans is rare. Available research has identified several risk factors that may be associated with infection including close direct contact with poultry and transmission via the environment. However, several important data gaps remain that limit our understanding of the epidemiology of H5N1 in humans. Although infection in humans with H5N1 remains rare, human cases continue to be reported and H5N1 is now considered endemic among poultry in parts of Asia and in Egypt, providing opportunities for additional human infections and for the acquisition of virus mutations that may lead to more efficient spread among humans and other mammalian species

  7. Genetic drift evolution under vaccination pressure among H5N1 Egyptian isolates

    OpenAIRE

    Afifi Manal A; Abdel-Moneim Ahmed S; El-Kady Magdy F

    2011-01-01

    Background The highly pathogenic H5N1 is a major avian pathogen that intensively affects the poultry industry in Egypt even in spite of the adoption of vaccination strategy. Antigenic drift is among the strategies the influenza virus uses to escape the immune system that might develop due to the pressure of extensive vaccination. H5N1 mutates in an intensified manner and is considered a potential candidate for the possible next pandemic with all the catastrophic consequences such an eventual...

  8. Phylogenetic and pathogenic analyses of avian influenza A H5N1 viruses isolated from poultry in Vietnam.

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    Dongming Zhao

    Full Text Available Despite great efforts to control the infection of poultry with H5N1 viruses, these pathogens continue to evolve and spread in nature, threatening public health. Elucidating the characteristics of H5N1 avian influenza virus will benefit disease control and pandemic preparation. Here, we sequenced the genomes of 15 H5N1 avian influenza viruses isolated in Vietnam in 2006 and 2007 and performed phylogenetic analyses to compare these sequences with those of other viruses available in the public databases. Molecular characterization of the H5N1 viruses revealed that seven genetically distinct clades of H5N1 viruses have appeared in Vietnam. Clade 2.3.4 viruses existed in Vietnam as early as 2005. Fifteen viruses isolated during 2006 and 2007 belonged to clade 1 and clade 2.3.4, and were divided into five genotypes. Reassortants between the clade 1 and clade 2.3.4 viruses were detected in both North and South Vietnam. We also assessed the replication and pathogenicity of these viruses in mice and found that these isolates replicated efficiently and exhibited distinct virulence in mice. Our results provide important information regarding the diversity of H5N1 viruses in nature.

  9. Influenza H5N1 virus infection of polarized human alveolar epithelial cells and lung microvascular endothelial cells

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    Yuen Kit M

    2009-10-01

    Full Text Available Abstract Background Highly pathogenic avian influenza (HPAI H5N1 virus is entrenched in poultry in Asia and Africa and continues to infect humans zoonotically causing acute respiratory disease syndrome and death. There is evidence that the virus may sometimes spread beyond respiratory tract to cause disseminated infection. The primary target cell for HPAI H5N1 virus in human lung is the alveolar epithelial cell. Alveolar epithelium and its adjacent lung microvascular endothelium form host barriers to the initiation of infection and dissemination of influenza H5N1 infection in humans. These are polarized cells and the polarity of influenza virus entry and egress as well as the secretion of cytokines and chemokines from the virus infected cells are likely to be central to the pathogenesis of human H5N1 disease. Aim To study influenza A (H5N1 virus replication and host innate immune responses in polarized primary human alveolar epithelial cells and lung microvascular endothelial cells and its relevance to the pathogenesis of human H5N1 disease. Methods We use an in vitro model of polarized primary human alveolar epithelial cells and lung microvascular endothelial cells grown in transwell culture inserts to compare infection with influenza A subtype H1N1 and H5N1 viruses via the apical or basolateral surfaces. Results We demonstrate that both influenza H1N1 and H5N1 viruses efficiently infect alveolar epithelial cells from both apical and basolateral surface of the epithelium but release of newly formed virus is mainly from the apical side of the epithelium. In contrast, influenza H5N1 virus, but not H1N1 virus, efficiently infected polarized microvascular endothelial cells from both apical and basolateral aspects. This provides a mechanistic explanation for how H5N1 virus may infect the lung from systemic circulation. Epidemiological evidence has implicated ingestion of virus-contaminated foods as the source of infection in some instances and our

  10. Influenza A H5N1 clade 2.3.4 virus with a different antiviral susceptibility profile replaced clade 1 virus in humans in northern Vietnam.

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    Mai T Q Le

    Full Text Available BACKGROUND: Prior to 2007, highly pathogenic avian influenza (HPAI H5N1 viruses isolated from poultry and humans in Vietnam were consistently reported to be clade 1 viruses, susceptible to oseltamivir but resistant to amantadine. Here we describe the re-emergence of human HPAI H5N1 virus infections in Vietnam in 2007 and the characteristics of the isolated viruses. METHODS AND FINDINGS: Respiratory specimens from patients suspected to be infected with avian influenza in 2007 were screened by influenza and H5 subtype specific polymerase chain reaction. Isolated H5N1 strains were further characterized by genome sequencing and drug susceptibility testing. Eleven poultry outbreak isolates from 2007 were included in the sequence analysis. Eight patients, all of them from northern Vietnam, were diagnosed with H5N1 in 2007 and five of them died. Phylogenetic analysis of H5N1 viruses isolated from humans and poultry in 2007 showed that clade 2.3.4 H5N1 viruses replaced clade 1 viruses in northern Vietnam. Four human H5N1 strains had eight-fold reduced in-vitro susceptibility to oseltamivir as compared to clade 1 viruses. In two poultry isolates the I117V mutation was found in the neuraminidase gene, which is associated with reduced susceptibility to oseltamivir. No mutations in the M2 gene conferring amantadine resistance were found. CONCLUSION: In 2007, H5N1 clade 2.3.4 viruses replaced clade 1 viruses in northern Vietnam and were susceptible to amantadine but showed reduced susceptibility to oseltamivir. Combination antiviral therapy with oseltamivir and amantadine for human cases in Vietnam is recommended.

  11. Highly pathogenic H5N1 influenza A virus strains provoke heterogeneous IFN-α/β responses that distinctively affect viral propagation in human cells.

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    Markus Matthaei

    Full Text Available The fatal transmissions of highly pathogenic avian influenza A viruses (IAV of the H5N1 subtype to humans and high titer replication in the respiratory tract indicate that these pathogens can overcome the bird-to-human species barrier. While type I interferons (IFN-α/β are well described to contribute to the species barrier of many zoonotic viruses, current data to the role of these antiviral cytokines during human H5N1 IAV infections is limited and contradictory. We hypothesized an important role for the IFN system in limiting productive infection of avian H5N1 strains in human cells. Hence, we examined IFN-α/β gene activation by different avian and human H5N1 isolates, if the IFN-α/β response restricts H5N1 growth and whether the different strains were equally capable to regulate the IFN-α/β system via their IFN-antagonistic NS1 proteins. Two human H5N1 isolates and a seasonal H3N2 strain propagated efficiently in human respiratory cells and induced little IFN-β, whereas three purely avian H5N1 strains were attenuated for replication and provoked higher IFN secretion. Replication of avian viruses was significantly enhanced on interferon-deficient cells, and exogenous IFN potently limited the growth of all strains in human cells. Moreover, IFN-α/β activation by all strains depended on retinoic acid-inducible gene I excluding principal differences in receptor activation between the different viruses. Interestingly, all H5N1 NS1 proteins suppressed IFN-α/β induction comparably well to the NS1 of seasonal IAV. Thus, our study shows that H5N1 strains are heterogeneous in their capacity to activate human cells in an NS1-independent manner. Our findings also suggest that H5N1 viruses need to acquire adaptive changes to circumvent strong IFN-α/β activation in human host cells. Since no single amino acid polymorphism could be associated with a respective high- or low induction phenotype we propose that the necessary adaptations to

  12. A recombinant vaccine of H5N1 HA1 fused with foldon and human IgG Fc induced complete cross-clade protection against divergent H5N1 viruses.

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    Lanying Du

    Full Text Available Development of effective vaccines to prevent influenza, particularly highly pathogenic avian influenza (HPAI caused by influenza A virus (IAV subtype H5N1, is a challenging goal. In this study, we designed and constructed two recombinant influenza vaccine candidates by fusing hemagglutinin 1 (HA1 fragment of A/Anhui/1/2005(H5N1 to either Fc of human IgG (HA1-Fc or foldon plus Fc (HA1-Fdc, and evaluated their immune responses and cross-protection against divergent strains of H5N1 virus. Results showed that these two recombinant vaccines induced strong immune responses in the vaccinated mice, which specifically reacted with HA1 proteins and an inactivated heterologous H5N1 virus. Both proteins were able to cross-neutralize infections by one homologous strain (clade 2.3 and four heterologous strains belonging to clades 0, 1, and 2.2 of H5N1 pseudoviruses as well as three heterologous strains (clades 0, 1, and 2.3.4 of H5N1 live virus. Importantly, immunization with these two vaccine candidates, especially HA1-Fdc, provided complete cross-clade protection against high-dose lethal challenge of different strains of H5N1 virus covering clade 0, 1, and 2.3.4 in the tested mouse model. This study suggests that the recombinant fusion proteins, particularly HA1-Fdc, could be developed into an efficacious universal H5N1 influenza vaccine, providing cross-protection against infections by divergent strains of highly pathogenic H5N1 virus.

  13. Evolutionary features of influenza A/H5N1 virus populations in Egypt: poultry and human health implications.

    Science.gov (United States)

    Naguib, Mahmoud M; Abdelwhab, E M; Harder, Timm C

    2016-07-01

    Since 2006, in Egypt, highly pathogenic avian influenza virus (HPAIV) H5N1 has established endemic status in poultry. Bayesian evolutionary analysis sampling trees suggested an introduction date in the third quarter of 2005. Evolutionary dynamics using Bayesian analysis showed that H5N1 viruses of clade 2.2.1.1 evolved at higher rates than those of clade 2.2.1.2. Bayesian skyline plot analysis of the HA gene of 840 and NA gene of 401 Egyptian H5N1 viruses from 2006-2015 identified two waves of viral population expansion correlating with the stepwise emergence of the 2.2.1.1 variant lineage in 2008 and with the newly emerging 2.2.1.2 cluster in late 2014. H5N1 infections in human hosts in 2014-2015 were statistically linked to a contemporary poultry outbreak.

  14. Clinical characteristics of 26 human cases of highly pathogenic avian influenza A (H5N1 virus infection in China.

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    Hongjie Yu

    Full Text Available BACKGROUND: While human cases of highly pathogenic avian influenza A (H5N1 virus infection continue to increase globally, available clinical data on H5N1 cases are limited. We conducted a retrospective study of 26 confirmed human H5N1 cases identified through surveillance in China from October 2005 through April 2008. METHODOLOGY/PRINCIPAL FINDINGS: Data were collected from hospital medical records of H5N1 cases and analyzed. The median age was 29 years (range 6-62 and 58% were female. Many H5N1 cases reported fever (92% and cough (58% at illness onset, and had lower respiratory findings of tachypnea and dyspnea at admission. All cases progressed rapidly to bilateral pneumonia. Clinical complications included acute respiratory distress syndrome (ARDS, 81%, cardiac failure (50%, elevated aminotransaminases (43%, and renal dysfunction (17%. Fatal cases had a lower median nadir platelet count (64.5 x 10(9 cells/L vs 93.0 x 10(9 cells/L, p = 0.02, higher median peak lactic dehydrogenase (LDH level (1982.5 U/L vs 1230.0 U/L, p = 0.001, higher percentage of ARDS (94% [n = 16] vs 56% [n = 5], p = 0.034 and more frequent cardiac failure (71% [n = 12] vs 11% [n = 1], p = 0.011 than nonfatal cases. A higher proportion of patients who received antiviral drugs survived compared to untreated (67% [8/12] vs 7% [1/14], p = 0.003. CONCLUSIONS/SIGNIFICANCE: The clinical course of Chinese H5N1 cases is characterized by fever and cough initially, with rapid progression to lower respiratory disease. Decreased platelet count, elevated LDH level, ARDS and cardiac failure were associated with fatal outcomes. Clinical management of H5N1 cases should be standardized in China to include early antiviral treatment for suspected H5N1 cases.

  15. H5N1 avian influenza virus: human cases reported in southern China.

    NARCIS (Netherlands)

    Crofts, J.; Paget, J.; Karcher, F.

    2003-01-01

    Two cases of confirmed influenza due to the avian influenza A H5N1 virus were reported last week in Hong Kong (1). The cases occurred in a Hong Kong family who had recently visited Fujian province in southern China. The daughter, aged 8 years, died following a respiratory illness. The cause of her d

  16. A Systematic Review of the Comparative Epidemiology of Avian and Human Influenza A H5N1 and H7N9 - Lessons and Unanswered Questions.

    Science.gov (United States)

    Bui, C; Bethmont, A; Chughtai, A A; Gardner, L; Sarkar, S; Hassan, S; Seale, H; MacIntyre, C R

    2016-12-01

    The aim of this work was to explore the comparative epidemiology of influenza viruses, H5N1 and H7N9, in both bird and human populations. Specifically, the article examines similarities and differences between the two viruses in their genetic characteristics, distribution patterns in human and bird populations and postulated mechanisms of global spread. In summary, H5N1 is pathogenic in birds, while H7N9 is not. Yet both have caused sporadic human cases, without evidence of sustained, human-to-human spread. The number of H7N9 human cases in the first year following its emergence far exceeded that of H5N1 over the same time frame. Despite the higher incidence of H7N9, the spatial distribution of H5N1 within a comparable time frame is considerably greater than that of H7N9, both within China and globally. The pattern of spread of H5N1 in humans and birds around the world is consistent with spread through wild bird migration and poultry trade activities. In contrast, human cases of H7N9 and isolations of H7N9 in birds and the environment have largely occurred in a number of contiguous provinces in south-eastern China. Although rates of contact with birds appear to be similar in H5N1 and H7N9 cases, there is a predominance of incidental contact reported for H7N9 as opposed to close, high-risk contact for H5N1. Despite the high number of human cases of H7N9 and the assumed transmission being from birds, the corresponding level of H7N9 virus in birds in surveillance studies has been low, particularly in poultry farms. H7N9 viruses are also diversifying at a much greater rate than H5N1 viruses. Analyses of certain H7N9 strains demonstrate similarities with engineered transmissible H5N1 viruses which make it more adaptable to the human respiratory tract. These differences in the human and bird epidemiology of H5N1 and H7N9 raise unanswered questions as to how H7N9 has spread, which should be investigated further.

  17. Risk Distribution of Human Infections with Avian Influenza H7N9 and H5N1 virus in China.

    Science.gov (United States)

    Li, Xin-Lou; Yang, Yang; Sun, Ye; Chen, Wan-Jun; Sun, Ruo-Xi; Liu, Kun; Ma, Mai-Juan; Liang, Song; Yao, Hong-Wu; Gray, Gregory C; Fang, Li-Qun; Cao, Wu-Chun

    2015-12-22

    It has been documented that the epidemiological characteristics of human infections with H7N9 differ significantly between H5N1. However, potential factors that may explain the different spatial distributions remain unexplored. We use boosted regression tree (BRT) models to explore the association of agro-ecological, environmental and meteorological variables with the occurrence of human cases of H7N9 and H5N1, and map the probabilities of occurrence of human cases. Live poultry markets, density of human, coverage of built-up land, relative humidity and precipitation were significant predictors for both. In addition, density of poultry, coverage of shrub and temperature played important roles for human H7N9 infection, whereas human H5N1 infection was associated with coverage of forest and water body. Based on the risks and distribution of ecological characteristics which may facilitate the circulation of the two viruses, we found Yangtze River Delta and Pearl River Delta, along with a few spots on the southeast coastline, to be the high risk areas for H7N9 and H5N1. Additional, H5N1 risk spots were identified in eastern Sichuan and southern Yunnan Provinces. Surveillance of the two viruses needs to be enhanced in these high risk areas to reduce the risk of future epidemics of avian influenza in China.

  18. Identifikasi Flu Burung H5N1 pada Unggas di Sekitar Kasus Flu Burung pada Manusia Tahun 2011 di Bekasi (AVIAN INFLUENZA H5N1 IDENTIFICATION IN AVIAN SPECIES SURROUNDING AVIAN INFLUENZA H5N1 HUMAN CASES IN BEKASI, WEST JAVA, 2011

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    Dyah Ayu Hewajuli

    2014-05-01

    Full Text Available H5N1 subtype Avian Influenza (AI virus is the causal agent  of AI disease in humans. In Indonesia,the first human AI occurred in Tangerang 2005.  Human AI in Indonesia has now spread into 12 provinces,including West Java, Jakarta, Banten, North Sumatra, East Java, Central Java, Lampung, South Sulawesi,West Sumatra, South Sumatra, Riau, and Bali. Until 2011, the total human AI cases were 182 cases  with150 deaths. This study was conducted to identify of H5N1 AI virus in birds in area surrounding a humanAI human case  in Bekasi city  in March 2011 and to investigate its role in the spread of AI to humans usingmethods of Hemaglutination Inhibition (HI , and Reverse Transcriptase-Polymerase Chain Reaction(RT-PCR. The result showed that 80% of birds in the area surrounding AI  surrounding H5N1 AI humancase in Bekasi 2011 were antibody negative  against  H5N1-AI virus. Antibody against H5N1-AI viruswith the titer less than 4 log 2 was detected in 4.4%  of birds and  with antibody titer 04 4-7 log 2 in 15%of birds. By RT-PCR, H5N1 AI virus was not detected in 47.6% of bird samples. H5 positive and N1negative  AI virus was detected in  30.2% samples.  Only 11.2% samples showed positive for H5N1 AI virus.The results suggest that H5N1-AI virus affecting birds may have a positive role in transmitting to thevirus to human in Bekasi 2011.

  19. Isolation of Highly Pathogenic Avian Influenza H5N1 Virus from Saker Falcons (Falco cherrug in the Middle East

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    Henju Marjuki

    2009-01-01

    Full Text Available There is accumulating evidence that birds of prey are susceptible to fatal infection with highly pathogenic avian influenza (HPAI virus. We studied the antigenic, molecular, phylogenetic, and pathogenic properties of 2 HPAI H5N1 viruses isolated from dead falcons in Saudi Arabia and Kuwait in 2005 and 2007, respectively. Phylogenetic and antigenic analyses grouped both isolates in clade 2.2 (Qinghai-like viruses. However, the viruses appeared to have spread westward via different flyways. It remains unknown how these viruses spread so rapidly from Qinghai after the 2005 outbreak and how they were introduced into falcons in these two countries. The H5N1 outbreaks in the Middle East are believed by some to be mediated by wild migratory birds. However, sporting falcons may be at additional risk from the illegal import of live quail to feed them.

  20. The Mx1 Gene Protects Mice against the Pandemic 1918 and Highly Lethal Human H5N1 Influenza Viruses▿

    OpenAIRE

    2007-01-01

    Mice carrying a wild-type Mx1 gene (Mx1+/+) differ from standard laboratory mice (Mx1−/−) in being highly resistant to infection with common laboratory strains of influenza A virus. We report that Mx1 also protects mice against the pandemic human 1918 influenza virus and a highly lethal human H5N1 strain from Vietnam. Resistance to H5N1 of Mx1+/+ but not Mx1−/− mice was enhanced if the animals were treated with a single dose of exogenous alpha interferon before infection. Thus, the interferon...

  1. Acquisition of human-type receptor binding specificity by new H5N1 influenza virus sublineages during their emergence in birds in Egypt.

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    Yohei Watanabe

    2011-05-01

    Full Text Available Highly pathogenic avian influenza A virus subtype H5N1 is currently widespread in Asia, Europe, and Africa, with 60% mortality in humans. In particular, since 2009 Egypt has unexpectedly had the highest number of human cases of H5N1 virus infection, with more than 50% of the cases worldwide, but the basis for this high incidence has not been elucidated. A change in receptor binding affinity of the viral hemagglutinin (HA from α2,3- to α2,6-linked sialic acid (SA is thought to be necessary for H5N1 virus to become pandemic. In this study, we conducted a phylogenetic analysis of H5N1 viruses isolated between 2006 and 2009 in Egypt. The phylogenetic results showed that recent human isolates clustered disproportionally into several new H5 sublineages suggesting that their HAs have changed their receptor specificity. Using reverse genetics, we found that these H5 sublineages have acquired an enhanced binding affinity for α2,6 SA in combination with residual affinity for α2,3 SA, and identified the amino acid mutations that produced this new receptor specificity. Recombinant H5N1 viruses with a single mutation at HA residue 192 or a double mutation at HA residues 129 and 151 had increased attachment to and infectivity in the human lower respiratory tract but not in the larynx. These findings correlated with enhanced virulence of the mutant viruses in mice. Interestingly, these H5 viruses, with increased affinity to α2,6 SA, emerged during viral diversification in bird populations and subsequently spread to humans. Our findings suggested that emergence of new H5 sublineages with α2,6 SA specificity caused a subsequent increase in human H5N1 influenza virus infections in Egypt, and provided data for understanding the virus's pandemic potential.

  2. In vitro evolution of H5N1 avian influenza virus toward human-type receptor specificity.

    Science.gov (United States)

    Chen, Li-Mei; Blixt, Ola; Stevens, James; Lipatov, Aleksandr S; Davis, Charles T; Collins, Brian E; Cox, Nancy J; Paulson, James C; Donis, Ruben O

    2012-01-05

    Acquisition of α2-6 sialoside receptor specificity by α2-3 specific highly-pathogenic avian influenza viruses (H5N1) is thought to be a prerequisite for efficient transmission in humans. By in vitro selection for binding α2-6 sialosides, we identified four variant viruses with amino acid substitutions in the hemagglutinin (S227N, D187G, E190G, and Q196R) that revealed modestly increased α2-6 and minimally decreased α2-3 binding by glycan array analysis. However, a mutant virus combining Q196R with mutations from previous pandemic viruses (Q226L and G228S) revealed predominantly α2-6 binding. Unlike the wild type H5N1, this mutant virus was transmitted by direct contact in the ferret model although not by airborne respiratory droplets. However, a reassortant virus with the mutant hemagglutinin, a human N2 neuraminidase and internal genes from an H5N1 virus was partially transmitted via respiratory droplets. The complex changes required for airborne transmissibility in ferrets suggest that extensive evolution is needed for H5N1 transmissibility in humans.

  3. Human influenza A H5N1 in Indonesia: health care service-associated delays in treatment initiation.

    Science.gov (United States)

    Adisasmito, Wiku; Aisyah, Dewi Nur; Aditama, Tjandra Yoga; Kusriastuti, Rita; Trihono; Suwandono, Agus; Sampurno, Ondri Dwi; Prasenohadi; Sapada, Nurshanty A; Mamahit, M J N; Swenson, Anna; Dreyer, Nancy A; Coker, Richard

    2013-06-11

    Indonesia has had more recorded human cases of influenza A H5N1 than any other country, with one of the world's highest case fatality rates. Understanding barriers to treatment may help ensure life-saving influenza-specific treatment is provided early enough to meaningfully improve clinical outcomes. Data for this observational study of humans infected with influenza A H5N1 were obtained primarily from Ministry of Health, Provincial and District Health Office clinical records. Data included time from symptom onset to presentation for medical care, source of medical care provided, influenza virology, time to initiation of influenza-specific treatment with antiviral drugs, and survival. Data on 124 human cases of virologically confirmed avian influenza were collected between September 2005 and December 2010, representing 73% of all reported Indonesia cases. The median time from health service presentation to antiviral drug initiation was 7.0 days. Time to viral testing was highly correlated with starting antiviral treatment (p influenza H5N1 in Indonesia appear related to delays in diagnosis rather than presentation to health care settings. Either cases are not suspected of being H5N1 cases until nearly one week after presenting for medical care, or viral testing and/or antiviral treatment is not available where patients are presenting for care. Health system delays have increased since 2007.

  4. Comprehensive analysis of antibody recognition in convalescent humans from highly pathogenic avian influenza H5N1 infection.

    Science.gov (United States)

    Zuo, Teng; Sun, Jianfeng; Wang, Guiqin; Jiang, Liwei; Zuo, Yanan; Li, Danyang; Shi, Xuanling; Liu, Xi; Fan, Shilong; Ren, Huanhuan; Hu, Hongxing; Sun, Lina; Zhou, Boping; Liang, Mifang; Zhou, Paul; Wang, Xinquan; Zhang, Linqi

    2015-12-04

    Understanding the mechanism of protective antibody recognition against highly pathogenic avian influenza A virus H5N1 in humans is critical for the development of effective therapies and vaccines. Here we report the crystal structure of three H5-specific human monoclonal antibodies bound to the globular head of hemagglutinin (HA) with distinct epitope specificities, neutralization potencies and breadth. A structural and functional analysis of these epitopes combined with those reported elsewhere identifies four major vulnerable sites on the globular head of H5N1 HA. Chimeric and vulnerable site-specific mutant pseudoviruses are generated to delineate broad neutralization specificities of convalescent sera from two individuals who recovered from the infection with H5N1 virus. Our results show that the four vulnerable sites on the globular head rather than the stem region are the major neutralizing targets, suggesting that during natural H5N1 infection neutralizing antibodies against the globular head work in concert to provide protective antibody-mediated immunity.

  5. Genetic characterization and pathogenicity assessment of highly pathogenic H5N1 avian influenza viruses isolated from migratory wild birds in 2011, South Korea.

    Science.gov (United States)

    Kwon, Hyeok-Il; Song, Min-Suk; Pascua, Philippe Noriel Q; Baek, Yun Hee; Lee, Jun Han; Hong, Seung-Pyo; Rho, Jong-Bok; Kim, Jeong-Ki; Poo, Haryoung; Kim, Chul-Joong; Choi, Young Ki

    2011-09-01

    The continued spread of a highly pathogenic avian influenza (HPAI) H5N1 virus among wild birds and poultry has posed a potential threat to human public health. In the present study, we report the isolation of HPAI H5N1 viruses (A/Md/Korea/W401/11 and A/Md/Korea/W404/11) from fecal samples of migratory birds. Genetic and phlyogenetic analyses demonstrated that these viruses are genetically identical possessing gene segments from avian virus origin and showing highest sequence similarities (as high as 99.8%) to A/Ws/Hokkaido/4/11 and 2009-2010 Mongolian-like clade 2.3.2 isolates rather than previous Korean H5N1 viruses. Both viruses possess the polybasic motif (QRERRRK/R) in HA but other genes did not bear additional virulence markers. Pathogenicity of A/Md/Korea/W401/11 was assessed and compared with a 2006 clade 2.2 HPAI H5N1 migratory bird isolate (A/EM/Korea/W149/06) in chickens, ducks, mice and ferrets. Experimental infection in these hosts showed that both viruses have high pathogenic potential in chickens (2.3-3.0 LD(50)s) and mice (3.3-3.9 LD(50)s), but A/Md/Korea/W401/11 was less pathogenic in duck and ferret models. Despite recovery of both infection viruses in the upper respiratory tract, efficient ferret-to-ferret transmission was not observed. These data suggest that the 2011 Korean HPAI wild bird H5N1 virus could replicate in mammalian hosts without pre-adaptation but could not sustain subsequent infection. This study highlights the role of migratory birds in the perpetuation and spread of HPAI H5N1 viruses in Far-East Asia. With the changing pathobiology caused by H5N1 viruses among wild and poultry birds, continued surveillance of influenza viruses among migratory bird species remains crucial for effective monitoring of high-pathogenicity or pandemic influenza viruses.

  6. Molecular analysis of Hemagglutinin Gen of Highly Pathogenic Avian Influenza of H5N1 Subtype Isolated from Waterfowls

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    R Susanti

    2008-10-01

    Full Text Available Avian influenza viruses (AIV subtype H5N1 isolated from waterfowls in West Java pose the known characteristic of highly pathogenic strains, with polybasic amino acid sequence of cleavage site QRERRRKKR and QRESRRKKR. This research aimed to analyze the important domains of hemagglutinin (HA gene of those isolates. Fragment of HA gene was amplified using RT-PCR method with specifically-designed primer pairs and sequenced using dideoxy termination method with ABI automatic sequencer (Applied Biosystems. Multiple alignment of nucleotide and deduced amino acid sequences were analyzed using ClustalW of MEGA-3.1 program. Some of biological domains of HA, i.e. antigenic sites, receptor binding pocket, and glycosylation sites of the isolates were polymorphic. The viruses also pose conserved glutamine (Q and glisin (G residues at the known receptor binding site, at the position 222 and 224 respectively. This findings clearly show that all AIV subtype H5N1 isolaed from waterfowl preservesthe α-2,3NeuAcGal avian receptor specificity.

  7. A molecular and antigenic survey of H5N1 highly pathogenic avian influenza virus isolates from smallholder duck farms in Central Java, Indonesia during 2007-2008.

    Science.gov (United States)

    Wibawa, Hendra; Henning, Joerg; Wong, Frank; Selleck, Paul; Junaidi, Akhmad; Bingham, John; Daniels, Peter; Meers, Joanne

    2011-09-07

    Indonesia is one of the countries most severely affected by H5N1 highly pathogenic avian influenza (HPAI) virus in terms of poultry and human health. However, there is little information on the diversity of H5N1 viruses circulating in backyard farms, where chickens and ducks often intermingle. In this study, H5N1 virus infection occurring in 96 smallholder duck farms in central Java, Indonesia from 2007-2008 was investigated and the molecular and antigenic characteristics of H5N1 viruses isolated from these farms were analysed. All 84 characterised viruses belonged to H5N1 clade 2.1 with three virus sublineages being identified: clade 2.1.1 (1), clade 2.1.3 (80), and IDN/6/05-like viruses (3) that did not belong to any of the present clades. All three clades were found in ducks, while only clade 2.1.3 was isolated from chickens. There were no significant amino acid mutations of the hemagglutinin (HA) and neuraminidase (NA) sites of the viruses, including the receptor binding, glycosylation, antigenic and catalytic sites and NA inhibitor targets. All the viruses had polybasic amino acids at the HA cleavage site. No evidence of major antigenic variants was detected. Based on the HA gene, identical virus variants could be found on different farms across the study sites and multiple genetic variants could be isolated from HPAI outbreaks simultaneously or at different time points from single farms. HPAI virus was isolated from both ducks and chickens; however, the proportion of surviving duck cases was considerably higher than in chickens. The 2.1.3 clade was the most common lineage found in this study. All the viruses had sequence characteristic of HPAI, but negligible variations in other recognized amino acids at the HA and NA proteins which determine virus phenotypes. Multiple genetic variants appeared to be circulating simultaneously within poultry communities. The high proportion of live duck cases compared to chickens over the study period suggests that ducks are

  8. A molecular and antigenic survey of H5N1 highly pathogenic avian influenza virus isolates from smallholder duck farms in Central Java, Indonesia during 2007-2008

    Directory of Open Access Journals (Sweden)

    Junaidi Akhmad

    2011-09-01

    Full Text Available Abstract Background Indonesia is one of the countries most severely affected by H5N1 highly pathogenic avian influenza (HPAI virus in terms of poultry and human health. However, there is little information on the diversity of H5N1 viruses circulating in backyard farms, where chickens and ducks often intermingle. In this study, H5N1 virus infection occurring in 96 smallholder duck farms in central Java, Indonesia from 2007-2008 was investigated and the molecular and antigenic characteristics of H5N1 viruses isolated from these farms were analysed. Results All 84 characterised viruses belonged to H5N1 clade 2.1 with three virus sublineages being identified: clade 2.1.1 (1, clade 2.1.3 (80, and IDN/6/05-like viruses (3 that did not belong to any of the present clades. All three clades were found in ducks, while only clade 2.1.3 was isolated from chickens. There were no significant amino acid mutations of the hemagglutinin (HA and neuraminidase (NA sites of the viruses, including the receptor binding, glycosylation, antigenic and catalytic sites and NA inhibitor targets. All the viruses had polybasic amino acids at the HA cleavage site. No evidence of major antigenic variants was detected. Based on the HA gene, identical virus variants could be found on different farms across the study sites and multiple genetic variants could be isolated from HPAI outbreaks simultaneously or at different time points from single farms. HPAI virus was isolated from both ducks and chickens; however, the proportion of surviving duck cases was considerably higher than in chickens. Conclusions The 2.1.3 clade was the most common lineage found in this study. All the viruses had sequence characteristic of HPAI, but negligible variations in other recognized amino acids at the HA and NA proteins which determine virus phenotypes. Multiple genetic variants appeared to be circulating simultaneously within poultry communities. The high proportion of live duck cases compared to

  9. The Mx1 gene protects mice against the pandemic 1918 and highly lethal human H5N1 influenza viruses.

    Science.gov (United States)

    Tumpey, Terrence M; Szretter, Kristy J; Van Hoeven, Neal; Katz, Jacqueline M; Kochs, Georg; Haller, Otto; García-Sastre, Adolfo; Staeheli, Peter

    2007-10-01

    Mice carrying a wild-type Mx1 gene (Mx1+/+) differ from standard laboratory mice (Mx1-/-) in being highly resistant to infection with common laboratory strains of influenza A virus. We report that Mx1 also protects mice against the pandemic human 1918 influenza virus and a highly lethal human H5N1 strain from Vietnam. Resistance to H5N1 of Mx1+/+ but not Mx1-/- mice was enhanced if the animals were treated with a single dose of exogenous alpha interferon before infection. Thus, the interferon-induced resistance factor Mx1 represents a key component of the murine innate immune system that mediates protection against epidemic and pandemic influenza viruses.

  10. Contact variables for exposure to avian influenza H5N1 virus at the human-animal interface.

    Science.gov (United States)

    Rabinowitz, P; Perdue, M; Mumford, E

    2010-06-01

    Although the highly pathogenic avian influenza H5N1 virus continues to cause infections in both avian and human populations, the specific zoonotic risk factors remain poorly understood. This review summarizes available evidence regarding types of contact associated with transmission of H5N1 virus at the human-animal interface. A systematic search of the published literature revealed five analytical studies and 15 case reports describing avian influenza transmission from animals to humans for further review. Risk factors identified in analytical studies were compared, and World Health Organization-confirmed cases, identified in case reports, were classified according to type of contact reported using a standardized algorithm. Although cases were primarily associated with direct contact with sick/unexpectedly dead birds, some cases reported only indirect contact with birds or contaminated environments or contact with apparently healthy birds. Specific types of contacts or activities leading to exposure could not be determined from data available in the publications reviewed. These results support previous reports that direct contact with sick birds is not the only means of human exposure to avian influenza H5N1 virus. To target public health measures and disease awareness messaging for reducing the risk of zoonotic infection with avian influenza H5N1 virus, the specific types of contacts and activities leading to transmission need to be further understood. The role of environmental virus persistence, shedding of virus by asymptomatic poultry and disease pathophysiology in different avian species relative to human zoonotic risk, as well as specific modes of zoonotic transmission, should be determined.

  11. Apoptosis and Proinflammatory Cytokine Responses of Primary Mouse Microglia and Astrocytes Induced by Human H1N1 and Avian H5N1 Influenza Viruses

    Institute of Scientific and Technical Information of China (English)

    Gefei Wang; Kangsheng Li; Juan Zhang; Weizhong Li; Gang Xin; Yun Su; Yuanli Gao; Heng Zhang; Guimei Lin; Xiaoyang Jiao

    2008-01-01

    Patients with an influenza virus infection can be complicated by acute encephalopathy and encephalitis. To investigate the immune reactions involved in the neurocomplication, mouse microglia and astrocytes were isolated,infected with human H1N1 and avian H5N1 influenza viruses, and examined for their immune responses. We observed homogeneously distributed viral receptors, sialic acid (SA)-α2,3-Galactose (Gal) and SA-α2,6-Gal, on microglia and astrocytes. Both viruses were replicative and productive in microglia and astrocytes. Virus-induced apoptosis and cytopathy in infected cells were observed at 24 h post-infection (p.i.). Expression of IL-1β, IL-6 and TNF-α mRNA examined at 6 h and 24 h p.i. Was up-regulated, and their expression levels were considerably higher in H5N1 infection. The amounts of secreted proinflammatory IL-1β, IL-6 and TNF-α at 6 h and 24 h p.i. Were also induced, with greater induction by H5N1 infection. This study is the first demonstration that both human H1N1 and avian H5N1 influenza viruses can infect mouse microglia and astrocytes and induce apoptosis, cytopathy, and proinflammatory cytokine production in them in vitro. Our results suggest that the direct cellular damage and the consequences of immunopathological injury in the CNS contribute to the influenza viral pathogenesis.

  12. In vitro evolution of H5N1 avian influenza virus toward human-type receptor specificity

    DEFF Research Database (Denmark)

    Chen, Li-Mei; Blixt, Klas Ola; Stevens, James

    2012-01-01

    Acquisition of a2-6 sialoside receptor specificity by a2-3 specific highly-pathogenic avian influenza viruses (H5N1) is thought to be a prerequisite for efficient transmission in humans. By in vitro selection for binding a2-6 sialosides, we identified four variant viruses with amino acid...... substitutions in the hemagglutinin (S227N, D187G, E190G, and Q196R) that revealed modestly increased a2-6 and minimally decreased a2-3 binding by glycan array analysis. However, a mutant virus combining Q196R with mutations from previous pandemic viruses (Q226L and G228S) revealed predominantly a2-6 binding....... Unlike the wild type H5N1, this mutant virus was transmitted by direct contact in the ferret model although not by airborne respiratory droplets. However, a reassortant virus with the mutant hemagglutinin, a human N2 neuraminidase and internal genes from an H5N1 virus was partially transmitted via...

  13. Identification of human host proteins contributing to H5N1 influenza virus propagation by membrane proteomics.

    Science.gov (United States)

    Liu, Cheng; Zhang, Anding; Guo, Jing; Yang, Jing; Zhou, Hongbo; Chen, Huanchun; Jin, Meilin

    2012-11-02

    The highly pathogenic avian influenza (HPAI) H5N1 virus is a highly virulent pathogen that causes respiratory diseases and death in humans and other animal species worldwide. Because influenza is an enveloped virus, the entry, assembly, and budding of virus particles are essential steps in the viral life cycle, and the virus relies on the participation of host cellular membrane proteins for all of these steps. Thus, we took a comparative membrane proteomics approach by using 2-DE coupled with MALDI-TOF/TOF MS to profile membrane proteins involved in H5N1 virus infection at 6, 12, and 24 h. Forty-two different proteins were found to vary on A549 cells due to H5N1 virus infection. Of these proteins, 57% were membrane or membrane-associated proteins. To further characterize the roles of novel identified proteins in virus propagation, the siRNA technology were applied and complement component C1q binding protein, annexin 2, prohibitin, peroxiredoxin 1 and heat shock protein 90-beta were successfully demonstrated to be contributed to viral propagation. In conclusion, the present study provides important new insight into understanding the roles of host membrane proteins in viral infection progress, and this insight is of particular importance for the development of novel therapeutic strategies.

  14. Highly Pathogenic Avian Influenza A(H5N1) Viruses at the Animal-Human Interface in Vietnam, 2003-2010.

    Science.gov (United States)

    Creanga, Adrian; Hang, Nguyen Le Khanh; Cuong, Vuong Duc; Nguyen, Ha T; Phuong, Hoang Vu Mai; Thanh, Le Thi; Thach, Nguyen Co; Hien, Pham Thi; Tung, Nguyen; Jang, Yunho; Balish, Amanda; Dang, Nguyen Hoang; Duong, Mai Thuy; Huong, Ngo Thu; Hoa, Do Ngoc; Tho, Nguyen Dang; Klimov, Alexander; Kapella, Bryan K; Gubareva, Larisa; Kile, James C; Hien, Nguyen Tran; Mai, Le Quynh; Davis, C Todd

    2017-09-15

    Mutation and reassortment of highly pathogenic avian influenza A(H5N1) viruses at the animal-human interface remain a major concern for emergence of viruses with pandemic potential. To understand the relationship of H5N1 viruses circulating in poultry and those isolated from humans, comprehensive phylogenetic and molecular analyses of viruses collected from both hosts in Vietnam between 2003 and 2010 were performed. We examined the temporal and spatial distribution of human cases relative to H5N1 poultry outbreaks and characterized the genetic lineages and amino acid substitutions in each gene segment identified in humans relative to closely related viruses from avian hosts. Six hemagglutinin clades and 8 genotypes were identified in humans, all of which were initially identified in poultry. Several amino acid mutations throughout the genomes of viruses isolated from humans were identified, indicating the potential for poultry viruses infecting humans to rapidly acquire molecular markers associated with mammalian adaptation and antiviral resistance. Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  15. 一起水禽H5N1疫情暴发后人群感染风险评估%Risk assessment of H5N1 human infection after an outbreak of avian influenza in water fowl

    Institute of Scientific and Technical Information of China (English)

    王玉林; 王鸣; 刘于飞; 蒋力云; 柳洋; 杨智聪; 郝爱华; 伍业健; 李海麟; 李铁钢

    2009-01-01

    目的 评估动物禽流感疫情暴发后人群感染的风险,探讨禽流感传播的可能性.方法 采用现场流行病学调查、分子流行病学、血清学研究及应急监测方法 ,对病、死禽的所有密切接触者进行医学观察;采用红细胞凝集抑制实验、实时荧光逆转录-聚合酶链式反应(RT-PCR)、基因测序方法 ,检测全部密切接触者的血清抗体,采集4个疫点环境标本检测禽流感H5核酸.结果 检测4个疫点环境标本22份,H5核酸阳性1份,序列分析与广州市2006年人禽流感病毒株A/China/GD01/2006(H5N1)的同源性为95.9%;检测疫区及周边2个农贸市场活禽交易场所环境标本62份,H5核酸均阴性;采集密切接触者的血样68份、咽拭子68份,禽流感H9抗体阳性6份,H5抗体、H5核酸均阴性,医学观察7 d,未发现禽流感感染者;应急监测区报告流感样患者337例,经排查未发现可疑禽流感患者.结论 此起水禽H5N1暴发未造成扩散,也未出现人感染病例,表明此次疫情的禽流感病毒H5N1对人的传播能力尚不强,引起人群感染的风险较低.%Objective To evaluate the risk of human infection after the outbreak of avian influenza H5N1 in animals.and probe the possibility for virus transmission.Methods By means of field epidemiological study,molecular epidemiology,serology and emergency surveillance,persons who had ever closely contacted with sick or dead poultry were observed.While,the RT-PCR and gene sequencing method were used to detect H5 nucleic acid from environmental swabs from 4 epidemic spots,and hemagglutination inhibition assay was also used to detect H5 antibody.Results of 22 environmental swabs detected from 4 epidemic spots,one was positive for H5 nucleic acid,and the homogeneity was 95.9% as compared with H5N1 virus A/China,/GD01/2006 (H5N1) found in Guangzhou in 2006 by gene sequence analysis.62 environmental swabs from live poultry stalls of food markets near epidemic spot were detected

  16. Comparison of human and animal surveillance data for H5N1 influenza A in Egypt 2006-2011.

    Directory of Open Access Journals (Sweden)

    Peter M Rabinowitz

    Full Text Available BACKGROUND: The majority of emerging infectious diseases are zoonotic (transmissible between animals and humans in origin, and therefore integrated surveillance of disease events in humans and animals has been recommended to support effective global response to disease emergence. While in the past decade there has been extensive global surveillance for highly pathogenic avian influenza (HPAI infection in both animals and humans, there have been few attempts to compare these data streams and evaluate the utility of such integration. METHODOLOGY: We compared reports of bird outbreaks of HPAI H5N1 in Egypt for 2006-2011 compiled by the World Organisation for Animal Health (OIE and the UN Food and Agriculture Organization (FAO EMPRESi reporting system with confirmed human H5N1 cases reported to the World Health Organization (WHO for Egypt during the same time period. PRINCIPAL FINDINGS: Both human cases and bird outbreaks showed a cyclic pattern for the country as a whole, and there was a statistically significant temporal correlation between the data streams. At the governorate level, the first outbreak in birds in a season usually but not always preceded the first human case, and the time lag between events varied widely, suggesting regional differences in zoonotic risk and/or surveillance effectiveness. In a multivariate risk model, lower temperature, lower urbanization, higher poultry density, and the recent occurrence of a bird outbreak were associated with increased risk of a human case of HPAI in the same governorate, although the positive predictive value of a bird outbreak was low. CONCLUSIONS: Integrating data streams of surveillance for human and animal cases of zoonotic disease holds promise for better prediction of disease risk and identification of environmental and regional factors that can affect risk. Such efforts can also point out gaps in human and animal surveillance systems and generate hypotheses regarding disease transmission.

  17. Recombinant human interferon reduces titer of the 1918 pandemic and H5N1 influenza viruses in a guinea pig model

    Science.gov (United States)

    Although H5N1 subtype influenza viruses have yet to acquire the ability to transmit efficiently among humans, the geographic expansion, genetic diversity and persistence of H5N1 viruses in birds indicates that pandemic potential of these viruses remains high. Vaccination remains the primary means f...

  18. Highly pathogenic avian influenza A(H5N1) mutants transmissible by air are susceptible to human and animal neutralizing antibodies.

    Science.gov (United States)

    Du, Lanying; Li, Ye; Zhao, Guangyu; Wang, Lili; Zou, Peng; Lu, Lu; Zhou, Yusen; Jiang, Shibo

    2013-10-15

    A laboratory-generated reassortant H5 hemagglutinin (HA)/influenza A(H1N1) strain containing 4 mutations in influenza A(H5N1) HA has become transmissible by air among mammals. Here, we constructed 15 influenza A(H5N1) pseudoviruses containing a single mutation or a combination of mutations and showed that the pseudoviruses were susceptible to neutralizing antibodies from patients with influenza A(H5N1) infection and from mice immunized with a vaccine containing the conserved HA1 sequence of influenza A(H5N1). These results indicate that antibodies in patients currently infected by influenza A(H5N1) and antibodies induced by vaccines containing conserved sequences in HA1 of wild-type influenza A(H5N1) are highly effective in cross-neutralizing future influenza A(H5N1) mutants with airborne transmissibility, suggesting that human influenza pandemics caused by these influenza A(H5N1) variants can be prevented.

  19. H5N1 whole-virus vaccine induces neutralizing antibodies in humans which are protective in a mouse passive transfer model.

    Directory of Open Access Journals (Sweden)

    M Keith Howard

    Full Text Available BACKGROUND: Vero cell culture-derived whole-virus H5N1 vaccines have been extensively tested in clinical trials and consistently demonstrated to be safe and immunogenic; however, clinical efficacy is difficult to evaluate in the absence of wide-spread human disease. A lethal mouse model has been utilized which allows investigation of the protective efficacy of active vaccination or passive transfer of vaccine induced sera following lethal H5N1 challenge. METHODS: We used passive transfer of immune sera to investigate antibody-mediated protection elicited by a Vero cell-derived, non-adjuvanted inactivated whole-virus H5N1 vaccine. Mice were injected intravenously with H5N1 vaccine-induced rodent or human immune sera and subsequently challenged with a lethal dose of wild-type H5N1 virus. RESULTS: Passive transfer of H5N1 vaccine-induced mouse, guinea pig and human immune sera provided dose-dependent protection of recipient mice against lethal challenge with wild-type H5N1 virus. Protective dose fifty values for serum H5N1 neutralizing antibody titers were calculated to be ≤1∶11 for all immune sera, independently of source species. CONCLUSIONS: These data underpin the confidence that the Vero cell culture-derived, whole-virus H5N1 vaccine will be effective in a pandemic situation and support the use of neutralizing serum antibody titers as a correlate of protection for H5N1 vaccines.

  20. Brief literature review for the WHO global influenza research agenda--highly pathogenic avian influenza H5N1 risk in humans.

    Science.gov (United States)

    Van Kerkhove, Maria D

    2013-09-01

    Highly pathogenic avian influenza A H5N1 viruses remain a significant health threat to humans given the continued rare occurrence of human cases with a high case fatality rate. This brief literature review summarizes available evidence of risk factors for H5N1 infection in humans and updates a recent systematic review published in early 2011. Several epidemiologic studies have been published to evaluate the risk factors for H5N1 infection in humans, including contact with poultry and poultry products and non-poultry-related contact such as from H5N1-contaminated water. While most H5N1 cases are attributed to exposure to sick poultry, it is unclear how many may be due to human-to-human transmission. The collective results of published literature suggest that transmission risk of H5N1 from poultry to humans may be highest among individuals who may have been in contact with the highest potential concentrations of virus shed by poultry. This suggests that there may be a threshold of virus concentration needed for effective transmission and that circulating H5N1 strains have not yet mutated to transmit readily from either poultry to human or from human to human. However, the mode of potential transmission can be quite varied throughout different countries and by study with exposures ranging from visiting a wet market, preparing infected poultry for consumption, to swimming or bathing in ponds frequented by poultry. Several important data gaps remain in the understanding of the epidemiology of H5N1 in humans and limit our ability to interpret the results of the available H5N1 seroepidemiologic studies.

  1. Generation, characterization and epitope mapping of two neutralizing and protective human recombinant antibodies against influenza A H5N1 viruses.

    Directory of Open Access Journals (Sweden)

    Lina Sun

    Full Text Available BACKGROUND: The development of new therapeutic targets and strategies to control highly pathogenic avian influenza (HPAI H5N1 virus infection in humans is urgently needed. Broadly cross-neutralizing recombinant human antibodies obtained from the survivors of H5N1 avian influenza provide an important role in immunotherapy for human H5N1 virus infection and definition of the critical epitopes for vaccine development. METHODOLOGY/PRINCIPAL FINDINGS: We have characterized two recombinant baculovirus-expressed human antibodies (rhAbs, AVFluIgG01 and AVFluIgG03, generated by screening a Fab antibody phage library derived from a patient recovered from infection with a highly pathogenic avian influenza A H5N1 clade 2.3 virus. AVFluIgG01 cross-neutralized the most of clade 0, clade 1, and clade 2 viruses tested, in contrast, AVFluIgG03 only neutralized clade 2 viruses. Passive immunization of mice with either AVFluIgG01 or AVFluIgG03 antibody resulted in protection from a lethal H5N1 clade 2.3 virus infection. Furthermore, through epitope mapping, we identify two distinct epitopes on H5 HA molecule recognized by these rhAbs and demonstrate their potential to protect against a lethal H5N1 virus infection in a mouse model. CONCLUSIONS/SIGNIFICANCE: Importantly, localization of the epitopes recognized by these two neutralizing and protective antibodies has provided, for the first time, insight into the human antibody responses to H5N1 viruses which contribute to the H5 immunity in the recovered patient. These results highlight the potential of a rhAbs treatment strategy for human H5N1 virus infection and provide new insight for the development of effective H5N1 pandemic vaccines.

  2. Characterization of a non-pathogenic H5N1 influenza virus isolated from a migratory duck flying from Siberia in Hokkaido, Japan, in October 2009

    Directory of Open Access Journals (Sweden)

    Okamatsu Masatoshi

    2011-02-01

    Full Text Available Abstract Background Infection with H5N1 highly pathogenic avian influenza viruses (HPAIVs of domestic poultry and wild birds has spread to more than 60 countries in Eurasia and Africa. It is concerned that HPAIVs may be perpetuated in the lakes in Siberia where migratory water birds nest in summer. To monitor whether HPAIVs circulate in migratory water birds, intensive surveillance of avian influenza has been performed in Mongolia and Japan in autumn each year. Until 2008, there had not been any H5N1 viruses isolated from migratory water birds that flew from their nesting lakes in Siberia. In autumn 2009, A/mallard/Hokkaido/24/09 (H5N1 (Mal/Hok/24/09 was isolated from a fecal sample of a mallard (Anas platyrhynchos that flew from Siberia to Hokkaido, Japan. The isolate was assessed for pathogenicity in chickens, domestic ducks, and quails and analyzed antigenically and phylogenetically. Results No clinical signs were observed in chickens inoculated intravenously with Mal/Hok/24/09 (H5N1. There was no viral replication in chickens inoculated intranasally with the isolate. None of the domestic ducks and quails inoculated intranasally with the isolate showed any clinical signs. There were no multiple basic amino acid residues at the cleavage site of the hemagglutinin (HA of the isolate. Each gene of Mal/Hok/24/09 (H5N1 is phylogenetically closely related to that of influenza viruses isolated from migratory water birds that flew from their nesting lakes in autumn. Additionally, the antigenicity of the HA of the isolate was similar to that of the viruses isolated from migratory water birds in Hokkaido that flew from their northern territory in autumn and different from those of HPAIVs isolated from birds found dead in China, Mongolia, and Japan on the way back to their northern territory in spring. Conclusion Mal/Hok/24/09 (H5N1 is a non-pathogenic avian influenza virus for chickens, domestic ducks, and quails, and is antigenically and genetically

  3. Differences in the Epidemiology of Human Cases of Avian Influenza A(H7N9) and A(H5N1) Viruses Infection

    Science.gov (United States)

    Qin, Ying; Horby, Peter W.; Tsang, Tim K.; Chen, Enfu; Gao, Lidong; Ou, Jianming; Nguyen, Tran Hien; Duong, Tran Nhu; Gasimov, Viktor; Feng, Luzhao; Wu, Peng; Jiang, Hui; Ren, Xiang; Peng, Zhibin; Li, Sa; Li, Ming; Zheng, Jiandong; Liu, Shelan; Hu, Shixiong; Hong, Rongtao; Farrar, Jeremy J.; Leung, Gabriel M.; Gao, George F.; Cowling, Benjamin J.; Yu, Hongjie

    2015-01-01

    Background. The pandemic potential of avian influenza viruses A(H5N1) and A(H7N9) remains an unresolved but critically important question. Methods. We compared the characteristics of sporadic and clustered cases of human H5N1 and H7N9 infection, estimated the relative risk of infection in blood-related contacts, and the reproduction number (R). Results. We assembled and analyzed data on 720 H5N1 cases and 460 H7N9 cases up to 2 November 2014. The severity and average age of sporadic/index cases of H7N9 was greater than secondary cases (71% requiring intensive care unit admission vs 33%, P = .007; median age 59 years vs 31, P H7N9. A higher proportion of H5N1 infections occurred in clusters (20%) compared to H7N9 (8%). The relative risk of infection in blood-related contacts of cases compared to unrelated contacts was 8.96 for H5N1 (95% CI, 1.30, 61.86) and 0.80 for H7N9 (95% CI, .32, 1.97). Conclusions. The results are consistent with an ascertainment bias towards severe and older cases for sporadic H7N9 but not for H5N1. The lack of evidence for ascertainment bias in sporadic H5N1 cases, the more pronounced clustering of cases, and the higher risk of infection in blood-related contacts, support the hypothesis that susceptibility to H5N1 may be limited and familial. This analysis suggests the potential pandemic risk may be greater for H7N9 than H5N1. PMID:25940354

  4. Avian Influenza A (H5N1)

    Centers for Disease Control (CDC) Podcasts

    2009-05-27

    In this podcast, CDC's Dr. Tim Uyeki discusses H5N1, a subtype of influenza A virus. This highly pathogenic H5N1 virus doesn't usually infect people, although some rare infections with H5N1 viruses have occurred in humans. We need to use a comprehensive strategy to prevent the spread of H5N1 virus among birds, including having human health and animal health work closely together.  Created: 5/27/2009 by Emerging Infectious Diseases.   Date Released: 5/27/2009.

  5. Systems-level comparison of host-responses elicited by avian H5N1 and seasonal H1N1 influenza viruses in primary human macrophages.

    Science.gov (United States)

    Lee, Suki M Y; Gardy, Jennifer L; Cheung, C Y; Cheung, Timothy K W; Hui, Kenrie P Y; Ip, Nancy Y; Guan, Y; Hancock, Robert E W; Peiris, J S Malik

    2009-12-14

    Human disease caused by highly pathogenic avian influenza (HPAI) H5N1 can lead to a rapidly progressive viral pneumonia leading to acute respiratory distress syndrome. There is increasing evidence from clinical, animal models and in vitro data, which suggests a role for virus-induced cytokine dysregulation in contributing to the pathogenesis of human H5N1 disease. The key target cells for the virus in the lung are the alveolar epithelium and alveolar macrophages, and we have shown that, compared to seasonal human influenza viruses, equivalent infecting doses of H5N1 viruses markedly up-regulate pro-inflammatory cytokines in both primary cell types in vitro. Whether this H5N1-induced dysregulation of host responses is driven by qualitative (i.e activation of unique host pathways in response to H5N1) or quantitative differences between seasonal influenza viruses is unclear. Here we used microarrays to analyze and compare the gene expression profiles in primary human macrophages at 1, 3, and 6 h after infection with H5N1 virus or low-pathogenic seasonal influenza A (H1N1) virus. We found that host responses to both viruses are qualitatively similar with the activation of nearly identical biological processes and pathways. However, in comparison to seasonal H1N1 virus, H5N1 infection elicits a quantitatively stronger host inflammatory response including type I interferon (IFN) and tumor necrosis factor (TNF)-alpha genes. A network-based analysis suggests that the synergy between IFN-beta and TNF-alpha results in an enhanced and sustained IFN and pro-inflammatory cytokine response at the early stage of viral infection that may contribute to the viral pathogenesis and this is of relevance to the design of novel therapeutic strategies for H5N1 induced respiratory disease.

  6. Systems-level comparison of host-responses elicited by avian H5N1 and seasonal H1N1 influenza viruses in primary human macrophages.

    Directory of Open Access Journals (Sweden)

    Suki M Y Lee

    Full Text Available Human disease caused by highly pathogenic avian influenza (HPAI H5N1 can lead to a rapidly progressive viral pneumonia leading to acute respiratory distress syndrome. There is increasing evidence from clinical, animal models and in vitro data, which suggests a role for virus-induced cytokine dysregulation in contributing to the pathogenesis of human H5N1 disease. The key target cells for the virus in the lung are the alveolar epithelium and alveolar macrophages, and we have shown that, compared to seasonal human influenza viruses, equivalent infecting doses of H5N1 viruses markedly up-regulate pro-inflammatory cytokines in both primary cell types in vitro. Whether this H5N1-induced dysregulation of host responses is driven by qualitative (i.e activation of unique host pathways in response to H5N1 or quantitative differences between seasonal influenza viruses is unclear. Here we used microarrays to analyze and compare the gene expression profiles in primary human macrophages at 1, 3, and 6 h after infection with H5N1 virus or low-pathogenic seasonal influenza A (H1N1 virus. We found that host responses to both viruses are qualitatively similar with the activation of nearly identical biological processes and pathways. However, in comparison to seasonal H1N1 virus, H5N1 infection elicits a quantitatively stronger host inflammatory response including type I interferon (IFN and tumor necrosis factor (TNF-alpha genes. A network-based analysis suggests that the synergy between IFN-beta and TNF-alpha results in an enhanced and sustained IFN and pro-inflammatory cytokine response at the early stage of viral infection that may contribute to the viral pathogenesis and this is of relevance to the design of novel therapeutic strategies for H5N1 induced respiratory disease.

  7. Sequence and phylogenetic analysis of highly pathogenic avian influenza H5N1 viruses isolated during 2006–2008 outbreaks in Pakistan reveals genetic diversity

    Directory of Open Access Journals (Sweden)

    Siddique Naila

    2012-12-01

    Full Text Available Abstract Background Since the first outbreak recorded in northern areas of Pakistan in early 2006, highly pathogenic avian influenza H5N1 viruses were isolated from commercial poultry and wild/domestic birds from different areas of Pakistan up to July 2008. Different isolates of H5N1 were sequenced to explore the genetic diversity of these viruses. Results Phylogenetic analysis revealed close clustering and highest sequence identity in all 8 genes to HPAI H5N1 isolates belonging to unified H5 clade 2.2, sub-lineage EMA-3 recovered from Afghanistan during the same time period. Two subgroups within Pakistani H5N1 viruses, from domestic and wild birds, were observed on the basis of their sequence homology and mutations. HPAI motif, preferred receptor specificity for α-(2, 3 linkages, potential N-linked glycosylation sites and an additional glycosylation site at the globular head of HA protein of four Pakistani H5N1 isolates. While, the amino acids associated with sensitivities to various antiviral drugs (Oseltamivir, Zanamivir, Amantadine were found conserved for the Pakistani H5N1 isolates. Conspicuously, some important mutations observed at critical positions of antigenic sites (S141P, D155S, R162I & P181S and at receptor binding pocket (A185T, R189K & S217P of HA-1. A high sequence similarity between Pakistani HP H5N1 and LP H9N2 viruses was also observed. Avian like host specific markers with the exception of E627K in PB2, K356R in PA, V33I in NP, I28V in M2 and L107F in NS2 proteins were also observed. Conclusions Various point mutations in different genes of H5 viruses from Pakistan were observed during its circulation in the field. The outbreaks started in Khyber Pakhtoon Khawa (North West province in 2006 and spread to the Southern regions over a period of time. Though migratory birds may have a role for this continued endemicity of clade 2.2 H5N1 viruses during 2006–2008 in Pakistan, the possibility of their transmission through legal

  8. Human mesenchymal stromal cells reduce influenza A H5N1-associated acute lung injury in vitro and in vivo.

    Science.gov (United States)

    Chan, Michael C W; Kuok, Denise I T; Leung, Connie Y H; Hui, Kenrie P Y; Valkenburg, Sophie A; Lau, Eric H Y; Nicholls, John M; Fang, Xiaohui; Guan, Yi; Lee, Jae W; Chan, Renee W Y; Webster, Robert G; Matthay, Michael A; Peiris, J S Malik

    2016-03-29

    Influenza can cause acute lung injury. Because immune responses often play a role, antivirals may not ensure a successful outcome. To identify pathogenic mechanisms and potential adjunctive therapeutic options, we compared the extent to which avian influenza A/H5N1 virus and seasonal influenza A/H1N1 virus impair alveolar fluid clearance and protein permeability in an in vitro model of acute lung injury, defined the role of virus-induced soluble mediators in these injury effects, and demonstrated that the effects are prevented or reduced by bone marrow-derived multipotent mesenchymal stromal cells. We verified the in vivo relevance of these findings in mice experimentally infected with influenza A/H5N1. We found that, in vitro, the alveolar epithelium's protein permeability and fluid clearance were dysregulated by soluble immune mediators released upon infection with avian (A/Hong Kong/483/97, H5N1) but not seasonal (A/Hong Kong/54/98, H1N1) influenza virus. The reduced alveolar fluid transport associated with down-regulation of sodium and chloride transporters was prevented or reduced by coculture with mesenchymal stromal cells. In vivo, treatment of aged H5N1-infected mice with mesenchymal stromal cells increased their likelihood of survival. We conclude that mesenchymal stromal cells significantly reduce the impairment of alveolar fluid clearance induced by A/H5N1 infection in vitro and prevent or reduce A/H5N1-associated acute lung injury in vivo. This potential adjunctive therapy for severe influenza-induced lung disease warrants rapid clinical investigation.

  9. 感染人类的禽流感病毒A(H5N1)研究进展%Update on avian influenza A(H5N1)virus infection in humans

    Institute of Scientific and Technical Information of China (English)

    钟晓琴; 王关嵩

    2009-01-01

    @@ 禽流感病毒A(H5N1)[avian influenza(H5N1)viruses]之前一直存在于鸟类,但却能导致人类疾病,并且具有高致死性和广泛流行的威胁.本文在综合了第二届世界卫生组织(World Health Organization,WHO)感染人类禽流感病毒A(H5N1)临床诊断咨询会议公布的研究信息[2]基础上,对2005年的报告[1]进行了更新.

  10. Reassortant H9N2 influenza viruses containing H5N1-like PB1 genes isolated from black-billed magpies in Southern China.

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    Guoying Dong

    Full Text Available H9N2 influenza A viruses have become endemic in different types of terrestrial poultry and wild birds in Asia, and are occasionally transmitted to humans and pigs. To evaluate the role of black-billed magpies (Pica pica in the evolution of influenza A virus, we conducted two epidemic surveys on avian influenza viruses in wild black-billed magpies in Guangxi, China in 2005 and characterized three isolated black-billed magpie H9N2 viruses (BbM viruses. Phylogenetic analysis indicated that three BbM viruses were almost identical with 99.7 to 100% nucleotide homology in their whole genomes, and were reassortants containing BJ94-like (Ck/BJ/1/94 HA, NA, M, and NS genes, SH/F/98-like (Ck/SH/F/98 PB2, PA, and NP genes, and H5N1-like (Ck/YN/1252/03, clade 1 PB1 genes. Genetic analysis showed that BbM viruses were most likely the result of multiple reassortments between co-circulating H9N2-like and H5N1-like viruses, and were genetically different from other H9N2 viruses because of the existence of H5N1-like PB1 genes. Genotypical analysis revealed that BbM viruses evolved from diverse sources and belonged to a novel genotype (B46 discovered in our recent study. Molecular analysis suggested that BbM viruses were likely low pathogenic reassortants. However, results of our pathogenicity study demonstrated that BbM viruses replicated efficiently in chickens and a mammalian mouse model but were not lethal for infected chickens and mice. Antigenic analysis showed that BbM viruses were antigenic heterologous with the H9N2 vaccine strain. Our study is probably the first report to document and characterize H9N2 influenza viruses isolated from black-billed magpies in southern China. Our results suggest that black-billed magpies were susceptible to H9N2 influenza viruses, which raise concerns over possible transmissions of reassortant H9N2 viruses among poultry and wild birds.

  11. Stepwise prediction and statistical screening: B-cell epitopes on neuraminidase of human avian H5N1 virus

    Institute of Scientific and Technical Information of China (English)

    HUANG Ping; YU ShouYi; KE ChangWen

    2008-01-01

    The B-cell epitopes of virus are associated with the antiviral drug and the vaccine screening. As the nucleotide sequences of neuraminidase (NA) of stain GD-01-06 were sequenced, we predicted the α-helix and β-fold structure and the indexes of the flexible regions of secondary structure of NA with methods of the Hydrophilicity plot by Kyte-Doolittle, the Surface probability plot by Emini and the Antigenic index by Jameson-Wolf, and then screened statistically the parameters to predict B-cell epitopes by the Hierarchical cluster and the Bivariate correlation and the quartiles with SPSS 13.0. The impact of variation of amino acids in NA on its epitopes was analyzed. The predictive results were evaluated by Wu's Antigenic Index and SWISS-MODEL. We found that the most possible epitopes on NA were located within or nearby its N-terminal Nos. 120-137, 81 -84, 408-415, 273-282, 429-432,356-368, 46-55,146-155, 341-350 and 198-209, which were the dominant regions of NA epitopes.Peptide 120-137 including the glycoprotein domain (NGT(126-128)) was first chosen as the B-cell epitopes on NA. NA in H5N1 strain isolated after 2003 lacked in No. 53 amino acid (I), resulting in an increase in the surface flexible region of NA in GD-01-06 and an enlargement to their epitope regions (VEP(46-48→VEPISNTNFL(46-55)). Conclusively, prediction of the B-cell epitopes on the NA based on multiple parameters is useful for researches on the molecular immunology and drug screening and immuno-prophylaxis. A deletion of No. 53 amino acid (I) in NA in strain GD-01-06 might increase its antigenicity.

  12. Reassortment between Avian H5N1 and human influenza viruses is mainly restricted to the matrix and neuraminidase gene segments.

    Science.gov (United States)

    Schrauwen, Eefje J A; Bestebroer, Theo M; Rimmelzwaan, Guus F; Osterhaus, Albert D M E; Fouchier, Ron A M; Herfst, Sander

    2013-01-01

    Highly pathogenic avian influenza H5N1 viruses have devastated the poultry industry in many countries of the eastern hemisphere. Occasionally H5N1 viruses cross the species barrier and infect humans, sometimes with a severe clinical outcome. When this happens, there is a chance of reassortment between H5N1 and human influenza viruses. To assess the potential of H5N1 viruses to reassort with contemporary human influenza viruses (H1N1, H3N2 and pandemic H1N1), we used an in vitro selection method to generate reassortant viruses, that contained the H5 hemagglutinin gene, and that have a replication advantage in vitro. We found that the neuraminidase and matrix gene segments of human influenza viruses were preferentially selected by H5 viruses. However, these H5 reassortant viruses did not show a marked increase in replication in MDCK cells and human bronchial epithelial cells. In ferrets, inoculation with a mixture of H5N1-pandemic H1N1 reassortant viruses resulted in outgrowth of reassortant H5 viruses that had incorporated the neuraminidase and matrix gene segment of pandemic 2009 H1N1. This virus was not transmitted via aerosols or respiratory droplets to naïve recipient ferrets. Altogether, these data emphasize the potential of avian H5N1 viruses to reassort with contemporary human influenza viruses. The neuraminidase and matrix gene segments of human influenza viruses showed the highest genetic compatibility with HPAI H5N1 virus.

  13. Reassortment between Avian H5N1 and human influenza viruses is mainly restricted to the matrix and neuraminidase gene segments.

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    Eefje J A Schrauwen

    Full Text Available Highly pathogenic avian influenza H5N1 viruses have devastated the poultry industry in many countries of the eastern hemisphere. Occasionally H5N1 viruses cross the species barrier and infect humans, sometimes with a severe clinical outcome. When this happens, there is a chance of reassortment between H5N1 and human influenza viruses. To assess the potential of H5N1 viruses to reassort with contemporary human influenza viruses (H1N1, H3N2 and pandemic H1N1, we used an in vitro selection method to generate reassortant viruses, that contained the H5 hemagglutinin gene, and that have a replication advantage in vitro. We found that the neuraminidase and matrix gene segments of human influenza viruses were preferentially selected by H5 viruses. However, these H5 reassortant viruses did not show a marked increase in replication in MDCK cells and human bronchial epithelial cells. In ferrets, inoculation with a mixture of H5N1-pandemic H1N1 reassortant viruses resulted in outgrowth of reassortant H5 viruses that had incorporated the neuraminidase and matrix gene segment of pandemic 2009 H1N1. This virus was not transmitted via aerosols or respiratory droplets to naïve recipient ferrets. Altogether, these data emphasize the potential of avian H5N1 viruses to reassort with contemporary human influenza viruses. The neuraminidase and matrix gene segments of human influenza viruses showed the highest genetic compatibility with HPAI H5N1 virus.

  14. Cross-reactive neuraminidase antibodies afford partial protection against H5N1 in mice and are present in unexposed humans.

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    Matthew R Sandbulte

    2007-02-01

    Full Text Available BACKGROUND: A pandemic H5N1 influenza outbreak would be facilitated by an absence of immunity to the avian-derived virus in the human population. Although this condition is likely in regard to hemagglutinin-mediated immunity, the neuraminidase (NA of H5N1 viruses (avN1 and of endemic human H1N1 viruses (huN1 are classified in the same serotype. We hypothesized that an immune response to huN1 could mediate cross-protection against H5N1 influenza virus infection. METHODS AND FINDINGS: Mice were immunized against the NA of a contemporary human H1N1 strain by DNA vaccination. They were challenged with recombinant A/Puerto Rico/8/34 (PR8 viruses bearing huN1 (PR8-huN1 or avN1 (PR8-avN1 or with H5N1 virus A/Vietnam/1203/04. Additional naïve mice were injected with sera from vaccinated mice prior to H5N1 challenge. Also, serum specimens from humans were analyzed for reactivity with avN1. Immunization elicited a serum IgG response to huN1 and robust protection against the homologous challenge virus. Immunized mice were partially protected from lethal challenge with H5N1 virus or recombinant PR8-avN1. Sera transferred from immunized mice to naïve animals conferred similar protection against H5N1 mortality. Analysis of human sera showed that antibodies able to inhibit the sialidase activity of avN1 exist in some individuals. CONCLUSIONS: These data reveal that humoral immunity elicited by huN1 can partially protect against H5N1 infection in a mammalian host. Our results suggest that a portion of the human population could have some degree of resistance to H5N1 influenza, with the possibility that this could be induced or enhanced through immunization with seasonal influenza vaccines.

  15. Additional Evidence That the Polymerase Subunits Contribute to the Viral Replication and the Virulence of H5N1 Avian Influenza Virus Isolates in Mice.

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    Xiao Qu

    Full Text Available Genetically similar H5N1 viruses circulating in the avian reservoir exhibit different levels of pathogenicity in mice. In this study, we characterized two highly pathogenic H5N1 avian isolates--A/Hunan/316/2005 (HN05, which is highly pathogenic in mice, and A/Hubei/489/2004 (HB04, which is nonpathogenic. In mammalian cells, HN05 replicates more efficiently than HB04, although both viruses have similar growth kinetics in avian cells. We used reverse genetics to generate recombinant H5N1 strains containing genes from HN05 and HB04 and examined their virulence. HN05 genes encoding the polymerase complex determine pathogenicity and viral replication ability both in vitro and in vivo. The PB2 subunit plays an important role in enhancing viral replication, and the PB1 and PA subunits contribute mainly to pathogenicity in mice. These results can be used to elucidate host-range expansion and the molecular basis of the high virulence of H5N1 viruses in mammalian species.

  16. Cross-recognition of avian H5N1 influenza virus by human cytotoxic T-lymphocyte populations directed to human influenza A virus

    NARCIS (Netherlands)

    J.H.C.M. Kreijtz (Joost); G. de Mutsert (Gerrie); C.A. van Baalen (Carel); R.A.M. Fouchier (Ron); A.D.M.E. Osterhaus (Albert); G.F. Rimmelzwaan (Guus)

    2008-01-01

    textabstractSince the number of human cases of infection with avian H5N1 influenza viruses is ever increasing, a pandemic outbreak caused by these viruses is feared. Therefore, in addition to virus-specific antibodies, there is considerable interest in immune correlates of protection against these v

  17. Identification of climate factors related to human infection with avian influenza A H7N9 and H5N1 viruses in China.

    Science.gov (United States)

    Li, Jing; Rao, Yuhan; Sun, Qinglan; Wu, Xiaoxu; Jin, Jiao; Bi, Yuhai; Chen, Jin; Lei, Fumin; Liu, Qiyong; Duan, Ziyuan; Ma, Juncai; Gao, George F; Liu, Di; Liu, Wenjun

    2015-12-11

    Human influenza infections display a strongly seasonal pattern. However, whether H7N9 and H5N1 infections correlate with climate factors has not been examined. Here, we analyzed 350 cases of H7N9 infection and 47 cases of H5N1 infection. The spatial characteristics of these cases revealed that H5N1 infections mainly occurred in the South, Middle, and Northwest of China, while the occurrence of H7N9 was concentrated in coastal areas of East and South of China. Aside from spatial-temporal characteristics, the most adaptive meteorological conditions for the occurrence of human infections by these two viral subtypes were different. We found that H7N9 infections correlate with climate factors, especially temperature (TEM) and relative humidity (RHU), while H5N1 infections correlate with TEM and atmospheric pressure (PRS). Hence, we propose a risky window (TEM 4-14 °C and RHU 65-95%) for H7N9 infection and (TEM 2-22 °C and PRS 980-1025 kPa) for H5N1 infection. Our results represent the first step in determining the effects of climate factors on two different virus infections in China and provide warning guidelines for the future when provinces fall into the risky windows. These findings revealed integrated predictive meteorological factors rooted in statistic data that enable the establishment of preventive actions and precautionary measures against future outbreaks.

  18. Identification of climate factors related to human infection with avian influenza A H7N9 and H5N1 viruses in China

    Science.gov (United States)

    Li, Jing; Rao, Yuhan; Sun, Qinglan; Wu, Xiaoxu; Jin, Jiao; Bi, Yuhai; Chen, Jin; Lei, Fumin; Liu, Qiyong; Duan, Ziyuan; Ma, Juncai; Gao, George F.; Liu, Di; Liu, Wenjun

    2015-01-01

    Human influenza infections display a strongly seasonal pattern. However, whether H7N9 and H5N1 infections correlate with climate factors has not been examined. Here, we analyzed 350 cases of H7N9 infection and 47 cases of H5N1 infection. The spatial characteristics of these cases revealed that H5N1 infections mainly occurred in the South, Middle, and Northwest of China, while the occurrence of H7N9 was concentrated in coastal areas of East and South of China. Aside from spatial-temporal characteristics, the most adaptive meteorological conditions for the occurrence of human infections by these two viral subtypes were different. We found that H7N9 infections correlate with climate factors, especially temperature (TEM) and relative humidity (RHU), while H5N1 infections correlate with TEM and atmospheric pressure (PRS). Hence, we propose a risky window (TEM 4–14 °C and RHU 65–95%) for H7N9 infection and (TEM 2–22 °C and PRS 980-1025 kPa) for H5N1 infection. Our results represent the first step in determining the effects of climate factors on two different virus infections in China and provide warning guidelines for the future when provinces fall into the risky windows. These findings revealed integrated predictive meteorological factors rooted in statistic data that enable the establishment of preventive actions and precautionary measures against future outbreaks. PMID:26656876

  19. Avian Influenza-the Epidemiology of Human H5N1 Cases Reported to WHO%世卫组织人间禽流感H5N1病例流行病学分析

    Institute of Scientific and Technical Information of China (English)

    张燕

    2007-01-01

    世卫组织在线出版的本周《疫情周报》提出了从2003—12/2006—04—30按发病日期向世卫组织正式报告的所有205例实验室确诊的H5N1病例流行病学数据首次分析结果。

  20. Live Poultry Trade in Southern China Provinces and HPAIV H5N1 Infection in Humans and Poultry: The Role of Chinese New Year Festivities

    Science.gov (United States)

    Soares Magalhães, Ricardo J.; Zhou, Xiaoyan; Jia, Beibei; Guo, Fusheng; Pfeiffer, Dirk U.; Martin, Vincent

    2012-01-01

    Background The number of outbreaks of highly pathogenic avian influenza virus of the H5N1 subtype (HPAIV H5N1) over the past 5 years has been drastically reduced in China but sporadic infections in poultry and humans are still occurring. In this study, we aimed to investigate seasonal patterns in the association between the movement of live poultry originating from southern China and HPAIV H5N1 infection history in humans and poultry in China. Methodology/Principal Findings During January to April 2010, longitudinal questionnaire surveys were carried out monthly in four wholesale live bird markets (LBMs) in Hunan and Guangxi provinces of South China. Using social network analysis, we found an increase in the number of observed links and degree centrality between LBMs and poultry sources in February and March compared to the months of January and April. The association of some live poultry traders (LPT’s) with a limited set of counties (within the catchment area of LBMs) in the months of February and March may support HPAIV H5N1 transmission and contribute to perpetuating HPAIV H5N1 virus circulation among certain groups of counties. The connectivity among counties experiencing human infection was significantly higher compared to counties without human infection for the months of January, March and April. Conversely, counties with poultry infections were found to be significantly less connected than counties without poultry infection for the month of February. Conclusions/Significance Our results show that temporal variation in live poultry trade in Southern China around the Chinese New Year festivities is associated with higher HPAIV H5N1 infection risk in humans and poultry. This study has shown that capturing the dynamic nature of poultry trade networks in Southern China improves our ability to explain the spatiotemporal dissemination in avian influenza viruses in China. PMID:23166751

  1. Human mesenchymal stromal cells reduce influenza A H5N1-associated acute lung injury in vitro and in vivo

    OpenAIRE

    Chan, Michael C W; Kuok, Denise I. T.; Leung, Connie Y. H.; Hui, Kenrie P Y; Valkenburg, Sophie A.; Lau, Eric H. Y.; Nicholls, John M; Fang, Xiaohui; Guan, Yi; Lee, Jae W; Chan, Renee W. Y.; Webster, Robert G; Matthay, Michael A.; Peiris, J. S. Malik

    2016-01-01

    Influenza can cause acute lung injury. Because immune responses often play a role, antivirals may not ensure a successful outcome. To identify pathogenic mechanisms and potential adjunctive therapeutic options, we compared the extent to which avian influenza A/H5N1 virus and seasonal influenza A/H1N1 virus impair alveolar fluid clearance and protein permeability in an in vitro model of acute lung injury, defined the role of virus-induced soluble mediators in these injury effects, and demonstr...

  2. AMINO ACID SEQUENCE MOTIVE OF OSELTAMIVIR BINDING POCKET IN NEURAMINIDASE PROTEIN OF AVIAN INFLUENZA (H5N1 VIRUS FROM HUMAN AND ANIMAL IN INDONESIA

    Directory of Open Access Journals (Sweden)

    I Gusti Ngurah Kade Mahardika

    2008-12-01

    Full Text Available Former finding that avian influenza (AI virus of H5N1 subtype from Indonesia shows reduced sensitivity against oseltamivir is critically reviewed trough molecular observation of the amino-acid sequence motive of neuraminidase protein (NA of all H5N1 virus from human and animal in Indonesia available in GeneBank. Amino acid sequence of oseltamivir binding pocket of NA protein on all Indonesian viruses is typical for sensitive virus with a concerved motive of H274, E276, R292 dan N294. Resistance issue could not be explained based on available data.

  3. Molecular analysis of hemagglutinin-1 fragment of avian influenza H5N1 viruses isolated from chicken farms in Indonesia from 2008 to 2010.

    Science.gov (United States)

    Mahardika, Gusti N; Jonas, Melina; Murwijati, Theresia; Fitria, Nur; Suartha, I Nyoman; Suartini, I Gusti A A; Wibawan, I Wayan Teguh

    2016-04-15

    Highly pathogenic avian influenza virus of subtype H5N1 (AIV-H5N1) has been circulating in Indonesia since 2003. To understand the genetic diversity of these viruses, and to predict vaccine efficacy, the hemaglutinin-1 (HA-1) fragment of viruses isolated from chicken farms in Indonesia from 2008 to 2010 was sequenced and analyzed. The effects of these molecular changes were investigated in challenge experiments and HI assays of homologous and heterologous strains. Molecular analysis showed that these AIV-H5N1 isolates had evolved into three distinct sub-lineages from an ancestor circulating since 2003. Although no significant positive selection of residues was detected, 12 negatively selected sites were identified (p<0.05). Moreover, four sites showed evidence of significant episodic diversifying selection. The findings indicated complete protectivity and high HI titers with homologous strains, compared with protectivity ranging from 40 to 100% and lower HI titers with heterologous strains resulting from polymorphisms at antigenic sites. Our findings provide valuable insight into the molecular evolution of AIV and have important implications for vaccine efficacy and future vaccination strategies. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. The emergence of influenza A H7N9 in human beings 16 years after influenza A H5N1: a tale of two cities.

    Science.gov (United States)

    To, Kelvin K W; Chan, Jasper F W; Chen, Honglin; Li, Lanjuan; Yuen, Kwok-Yung

    2013-09-01

    Infection with either influenza A H5N1 virus in 1997 or avian influenza A H7N9 virus in 2013 caused severe pneumonia that did not respond to typical or atypical antimicrobial treatment, and resulted in high mortality. Both viruses are reassortants with internal genes derived from avian influenza A H9N2 viruses that circulate in Asian poultry. Both viruses have genetic markers of mammalian adaptation in their haemagglutinin and polymerase PB2 subunits, which enhanced binding to human-type receptors and improved replication in mammals, respectively. Hong Kong (affected by H5N1 in 1997) and Shanghai (affected by H7N9 in 2013) are two rapidly flourishing cosmopolitan megacities that were increasing in human population and poultry consumption before the outbreaks. Both cities are located along the avian migratory route at the Pearl River delta and Yangtze River delta. Whether the widespread use of the H5N1 vaccine in east Asia-with suboptimum biosecurity measures in live poultry markets and farms-predisposed to the emergence of H7N9 or other virus subtypes needs further investigation. Why H7N9 seems to be more readily transmitted from poultry to people than H5N1 is still unclear.

  5. Antiviral Susceptibility of Highly Pathogenic Avian Influenza A(H5N1) Viruses Isolated from Poultry, Vietnam, 2009–2011

    OpenAIRE

    Nguyen, Ha T.; Nguyen, Tung; Mishin, Vasiliy P.; Sleeman, Katrina; Balish, Amanda; Jones, Joyce; Creanga, Adrian; Marjuki, Henju; Timothy M Uyeki; Nguyen, Dang H.; Nguyen, Diep T.; Do, Hoa T.; Klimov, Alexander I.; Davis, Charles T.; Gubareva, Larisa V.

    2013-01-01

    We assessed drug susceptibilities of 125 avian influenza A(H5N1) viruses isolated from poultry in Vietnam during 2009–2011. Of 25 clade 1.1 viruses, all possessed a marker of resistance to M2 blockers amantadine and rimantadine; 24 were inhibited by neuraminidase inhibitors. One clade 1.1 virus contained the R430W neuraminidase gene and reduced inhibition by oseltamivir, zanamivir, and laninamivir 12-, 73-, and 29-fold, respectively. Three of 30 clade 2.3.4 viruses contained a I223T mutation ...

  6. Isolation and identification of highly pathogenic avian influenza virus subtype H5N1 from emus from the Ein Gedi oasis by the Dead Sea.

    Science.gov (United States)

    Amnon, Inbar; Shkoda, Irina; Lapin, Ekaterina; Raibstein, Israel; Rosenbluth, Ezra; Nagar, Sagit; Perk, Shimon; Bellaiche, Michel; Davidson, Irit

    2011-09-01

    An avian influenza virus (AIV), A/Emu/Israel/552/2010/(H5N1), was isolated from a dead emu that was found in the Ein Gedi oasis near the Dead Sea. The virus molecular characterization was performed by reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time RT-PCR using AIV subtype-specific primers. The virus was of high pathogenicity, according to its intravenous pathogenicity index of 2.85 and the nucleotide sequencing at the cleavage site of the hemagglutinin gene, GERRRKKR, which is typical for highly pathogenic chicken influenza A viruses.

  7. AMINO-TERMINUS OF POLYMERASE BASIC-2 OF AVIAN INFLUENZA VIRUS OF H5N1 SUBTYPE ISOLATED FROM VARIOUS ANIMAL SPECIES IN INDONESIA

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    Gusti Ayu Yuniati Kencana

    2008-09-01

    Full Text Available The information on pathogenicity and adaptation factors of avian influenza virus (AIV in mammalsis very inportant in an effort to reduce the risk of avian influenza (AI pandemic in the future. Polymerasegene complex appears to be the major factors for adaptation of AIV to certain animal species. A preliminarystudy on role of non-coding region (NCR and amino-terminus of polymerase-basic 2 (PB2 is presented.Purified viral RNA of AIV isolated from chicken, duck, pig, and quail of Bali and Yogyakarta was reversetranscribed into cDNA and amplified using reverse transcriptase-polymerase chain reaction (RT-PCRusing PB-2 universal forward primer and specifically designed backward primer. The result showed thatall AIV’s H5N1 isolated from chicken, duck, quail, and pig, posed PB2 amino-terminus typical for IndonesianAIV H5N1. However, polymorphic amino acids of the protein fragment did not show any species specificmotive, with the exception of the pig isolate Sw/Tabanan/2006 which had specific substitution of D16E,H17Q, M40I, and H124Y.

  8. Characterization of human single-chain antibodies against highly pathogenic avian influenza H5N1 viruses: mimotope and neutralizing activity.

    Science.gov (United States)

    Yang, Jiupian; Yoshida, Reiko; Kariya, Yuki; Zhang, Xu; Hashiguchi, Shuhei; Nakashima, Toshihiro; Suda, Yasuo; Takada, Ayato; Ito, Yuji; Sugimura, Kazuhisa

    2010-10-01

    The development of new therapeutic targets and strategies to control highly pathogenic avian influenza (HPAI) H5N1 virus infection in humans is urgently needed. Neutralizing recombinant human antibodies would provide important agents for immunotherapy on human H5N1 virus infection and definition of the critical mimotope for vaccine development. In this study, we have characterized an anti-H5-specific scFv clone, 3D1 from the human-scFv-displaying phage library. 3D1 blocked the binding of H5-Fc to MDCK cells in flow cytometry and neutralized H5N1 subtype influenza A viruses in a microneutralization assay. Employing a peptide-displaying phage library, Ph.D-12, the mimotope was determined to be at #128-131 and #204-211 of H5, which are silic acid-binding regions. In consistency with this result, 3D1 binds the recombinant sugar-binding domain (#50G-#272E) produced by a baculovirus vector. The 3D1 antibody employs the germline gene VH1-23. As this antibody is the first human anti-H5 scFv clearly defined on the sugar-binding epitope, it allows us to investigate the influence of amino acid substitutions in this region on the determination of the binding specificity to either sialic acid α2,6-galactose (SA α2,6Gal) or sialic acid α2,3-galactose (SA α2,3Gal) providing new insight for the development of effective H5N1 pandemic vaccines.

  9. The epitope and neutralization mechanism of AVFluIgG01, a broad-reactive human monoclonal antibody against H5N1 influenza virus.

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    Zhiliang Cao

    Full Text Available The continued spread of highly pathogenic avian influenza (HPAI H5N1 virus underscores the importance of effective antiviral approaches. AVFluIgG01 is a potent and broad-reactive H5N1-neutralizing human monoclonal antibody (mAb showing great potential for use either for therapeutic purposes or as a basis of vaccine development, but its antigenic epitope and neutralization mechanism have not been finely characterized. In this study, we first demonstrated that AVFluIgG01 targets a novel conformation-dependent epitope in the globular head region of H5N1 hemagglutinin (HA. By selecting mimotopes from a random peptide library in combination with computational algorithms and site-directed mutagenesis, the epitope was mapped to three conserved discontinuous sites (I-III that are located closely at the three-dimensional structure of HA. Further, we found that this HA1-specific human mAb can efficiently block both virus-receptor binding and post-attachment steps, while its Fab fragment exerts the post-attachment inhibition only. Consistently, AVFluIgG01 could inhibit HA-mediated cell-cell membrane fusion at a dose-dependent manner and block the acquisition of pH-induced protease sensitivity. These results suggest a neutralization mechanism of AVFluIgG01 by simultaneously blocking viral attachment to the receptors on host cells and interfering with HA conformational rearrangements associated with membrane fusion. The presented data provide critical information for developing novel antiviral therapeutics and vaccines against HPAI H5N1 virus.

  10. Isolation and characterization of influenza A virus (subtype H5N1) that caused the first highly pathogenic avian influenza outbreak in chicken in Bhutan.

    Science.gov (United States)

    Dubey, S C; Dahal, N; Nagarajan, S; Tosh, C; Murugkar, H V; Rinzin, K; Sharma, B; Jain, R; Katare, M; Patil, S; Khandia, R; Syed, Z; Tripathi, S; Behera, P; Kumar, M; Kulkarni, D D; Krishna, Lal

    2012-02-24

    We characterized Influenza A/H5N1 virus that caused the first outbreak of highly pathogenic avian influenza (HPAI) in chickens in Bhutan in 2010. The virus was highly virulent to chicken, killing them within two days of the experimental inoculation with an intravenous pathogenicity index (IVPI) of 2.88. For genetic and phylogenetic analyses, complete genome sequencing of 4 viral isolates was carried out. The isolates revealed multiple basic amino acids at their hemagglutinin (HA) cleavage site, similar to other "Qinghai-like" H5N1 isolates. The receptor-binding site of HA molecule contained avian-like amino acids ((222)Q and (224)G). The isolates also contained amino acid residue K at position 627 of the PB2 protein, and other markers in NS 1 and PB1 proteins, highlighting the risk to mammals. However, the isolates were sensitive to influenza drugs presently available in the market. The sequence analysis indicated that the Bhutan viruses shared 99.1-100% nucleotide homology in all the eight genes among themselves and 2010 chicken isolate from Bangladesh (A/chicken/Bangladesh/1151-11/2010) indicating common progenitor virus. The phylogenetic analysis indicated that the Bhutan isolates belonged to sub-clade 2.2.3 (EMA 3) and shared common progenitor virus with the 2010 Bangladesh virus. Based on the evidence of phylogeny and molecular markers, it could be concluded that the outbreaks in Bhutan and Bangladesh in 2010 were due to independent introductions of the virus probably through migratory birds. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Antiviral susceptibility of highly pathogenic avian influenza A(H5N1) viruses isolated from poultry, Vietnam, 2009-2011.

    Science.gov (United States)

    Nguyen, Ha T; Nguyen, Tung; Mishin, Vasiliy P; Sleeman, Katrina; Balish, Amanda; Jones, Joyce; Creanga, Adrian; Marjuki, Henju; Uyeki, Timothy M; Nguyen, Dang H; Nguyen, Diep T; Do, Hoa T; Klimov, Alexander I; Davis, Charles T; Gubareva, Larisa V

    2013-12-01

    We assessed drug susceptibilities of 125 avian influenza A(H5N1) viruses isolated from poultry in Vietnam during 2009-2011. Of 25 clade 1.1 viruses, all possessed a marker of resistance to M2 blockers amantadine and rimantadine; 24 were inhibited by neuraminidase inhibitors. One clade 1.1 virus contained the R430W neuraminidase gene and reduced inhibition by oseltamivir, zanamivir, and laninamivir 12-, 73-, and 29-fold, respectively. Three of 30 clade 2.3.4 viruses contained a I223T mutation and showed 7-fold reduced inhibition by oseltamivir. One of 70 clade 2.3.2.1 viruses had the H275Y marker of oseltamivir resistance and exhibited highly reduced inhibition by oseltamivir and peramivir; antiviral agents DAS181 and favipiravir inhibited H275Y mutant virus replication in MDCK-SIAT1 cells. Replicative fitness of the H275Y mutant virus was comparable to that of wildtype virus. These findings highlight the role of drug susceptibility monitoring of H5N1 subtype viruses circulating among birds to inform antiviral stockpiling decisions for pandemic preparedness.

  12. Antiviral Susceptibility of Highly Pathogenic Avian Influenza A(H5N1) Viruses Isolated from Poultry, Vietnam, 2009–2011

    Science.gov (United States)

    Nguyen, Ha T.; Nguyen, Tung; Mishin, Vasiliy P.; Sleeman, Katrina; Balish, Amanda; Jones, Joyce; Creanga, Adrian; Marjuki, Henju; Uyeki, Timothy M.; Nguyen, Dang H.; Nguyen, Diep T.; Do, Hoa T.; Klimov, Alexander I.; Davis, Charles T.

    2013-01-01

    We assessed drug susceptibilities of 125 avian influenza A(H5N1) viruses isolated from poultry in Vietnam during 2009–2011. Of 25 clade 1.1 viruses, all possessed a marker of resistance to M2 blockers amantadine and rimantadine; 24 were inhibited by neuraminidase inhibitors. One clade 1.1 virus contained the R430W neuraminidase gene and reduced inhibition by oseltamivir, zanamivir, and laninamivir 12-, 73-, and 29-fold, respectively. Three of 30 clade 2.3.4 viruses contained a I223T mutation and showed 7-fold reduced inhibition by oseltamivir. One of 70 clade 2.3.2.1 viruses had the H275Y marker of oseltamivir resistance and exhibited highly reduced inhibition by oseltamivir and peramivir; antiviral agents DAS181 and favipiravir inhibited H275Y mutant virus replication in MDCK-SIAT1 cells. Replicative fitness of the H275Y mutant virus was comparable to that of wildtype virus. These findings highlight the role of drug susceptibility monitoring of H5N1 subtype viruses circulating among birds to inform antiviral stockpiling decisions for pandemic preparedness. PMID:24274711

  13. Physician's knowledge, attitudes, and practices regarding seasonal influenza, pandemic influenza, and highly pathogenic avian influenza A (H5N1) virus infections of humans in Indonesia.

    Science.gov (United States)

    Mangiri, Amalya; Iuliano, A Danielle; Wahyuningrum, Yunita; Praptiningsih, Catharina Y; Lafond, Kathryn E; Storms, Aaron D; Samaan, Gina; Ariawan, Iwan; Soeharno, Nugroho; Kreslake, Jennifer M; Storey, J Douglas; Uyeki, Timothy M

    2017-01-01

    Indonesia has reported highest number of fatal human cases of highly pathogenic avian influenza (HPAI) A (H5N1) virus infection worldwide since 2005. There are limited data available on seasonal and pandemic influenza in Indonesia. During 2012, we conducted a survey of clinicians in two districts in western Java, Indonesia, to assess knowledge, attitudes, and practices (KAP) of clinical diagnosis, testing, and treatment of patients with seasonal influenza, pandemic influenza, or HPAI H5N1 virus infections. Overall, a very low percentage of physician participants reported ever diagnosing hospitalized patients with seasonal, pandemic, or HPAI H5N1 influenza. Use of influenza testing was low in outpatients and hospitalized patients, and use of antiviral treatment was very low for clinically diagnosed influenza patients. Further research is needed to explore health system barriers for influenza diagnostic testing and availability of antivirals for treatment of influenza in Indonesia. © 2016 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  14. Intense circulation of A/H5N1 and other avian influenza viruses in Cambodian live-bird markets with serological evidence of sub-clinical human infections.

    Science.gov (United States)

    Horm, Srey Viseth; Tarantola, Arnaud; Rith, Sareth; Ly, Sowath; Gambaretti, Juliette; Duong, Veasna; Y, Phalla; Sorn, San; Holl, Davun; Allal, Lotfi; Kalpravidh, Wantanee; Dussart, Philippe; Horwood, Paul F; Buchy, Philippe

    2016-07-20

    Surveillance for avian influenza viruses (AIVs) in poultry and environmental samples was conducted in four live-bird markets in Cambodia from January through November 2013. Through real-time RT-PCR testing, AIVs were detected in 45% of 1048 samples collected throughout the year. Detection rates ranged from 32% and 18% in duck and chicken swabs, respectively, to 75% in carcass wash water samples. Influenza A/H5N1 virus was detected in 79% of samples positive for influenza A virus and 35% of all samples collected. Sequence analysis of full-length haemagglutinin (HA) and neuraminidase (NA) genes from A/H5N1 viruses, and full-genome analysis of six representative isolates, revealed that the clade 1.1.2 reassortant virus associated with Cambodian human cases during 2013 was the only A/H5N1 virus detected during the year. However, multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of HA and NA genes revealed co-circulation of at least nine low pathogenic AIVs from HA1, HA2, HA3, HA4, HA6, HA7, HA9, HA10 and HA11 subtypes. Four repeated serological surveys were conducted throughout the year in a cohort of 125 poultry workers. Serological testing found an overall prevalence of 4.5% and 1.8% for antibodies to A/H5N1 and A/H9N2, respectively. Seroconversion rates of 3.7 and 0.9 cases per 1000 person-months participation were detected for A/H5N1 and A/H9N2, respectively. Peak AIV circulation was associated with the Lunar New Year festival. Knowledge of periods of increased circulation of avian influenza in markets should inform intervention measures such as market cleaning and closures to reduce risk of human infections and emergence of novel AIVs.

  15. The non-structural (NS) gene segment of H9N2 influenza virus isolated from backyard poultry in Pakistan reveals strong genetic and functional similarities to the NS gene of highly pathogenic H5N1.

    Science.gov (United States)

    Munir, Muhammad; Zohari, Siamak; Iqbal, Munir; Abbas, Muhammad; Perez, Daniel Roberto; Berg, Mikael

    2013-10-01

    Apart from natural reassortment, co-circulation of different avian influenza virus strains in poultry populations can lead to generation of novel variants and reassortant viruses. In this report, we studied the genetics and functions of a reassorted non-structural gene (NS) of H9N2 influenza virus collected from back yard poultry (BYP) flock. Phylogenetic reconstruction based on hemagglutinin and neuraminidase genes indicates that an isolate from BYP belongs to H9N2. However, the NS gene-segment of this isolate cluster into genotype Z, clade 2.2 of the highly pathogenic H5N1. The NS gene plays essential roles in the host-adaptation, cell-tropism, and virulence of influenza viruses. However, such interpretations have not been investigated in naturally recombinant H9N2 viruses. Therefore, we compared the NS1 protein of H9N2 (H9N2/NS1) and highly pathogenic H5N1 (H5N1/NS1) in parallel for their abilities to regulate different signaling pathways, and investigated the molecular mechanisms of IFN-β production in human, avian, and mink lung cells. We found that H9N2/NS1 and H5N1/NS1 are comparably similar in inhibiting TNF-α induced nuclear factor κB and double stranded RNA induced activator protein 1 and interferon regulatory factor 3 transcription factors. Thus, the production of IFN-β was inhibited equally by both NS1s as demonstrated by IFN stimulatory response element and IFN-β promoter activation. Moreover, both NS1s predominantly localized in the nucleus when transfected to human A549 cells. This study therefore suggests the possible increased virulence of natural reassortant viruses for their efficient invasion of host immune responses, and proposes that these should not be overlooked for their epizootic and zoonotic potential.

  16. Human microRNA-24 modulates highly pathogenic avian-origin H5N1 influenza A virus infection in A549 cells by targeting secretory pathway furin.

    Science.gov (United States)

    Loveday, Emma-Kate; Diederich, Sandra; Pasick, John; Jean, François

    2015-01-01

    A common critical cellular event that many human enveloped viruses share is the requirement for proteolytic cleavage of the viral glycoprotein by furin in the host secretory pathway. For example, the furin-dependent proteolytic activation of highly pathogenic (HP) influenza A (infA) H5 and H7 haemagglutinin precursor (HA0) subtypes is critical for yielding fusion-competent infectious virions. In this study, we hypothesized that viral hijacking of the furin pathway by HP infA viruses to permit cleavage of HA0 could represent a novel molecular mechanism controlling the dynamic production of fusion-competent infectious virus particles during the viral life cycle. We explored the biological role of a newly identified furin-directed human microRNA, miR-24, in this process as a potential post-transcriptional regulator of the furin-mediated activation of HA0 and production of fusion-competent virions in the host secretory pathway. We report that miR-24 and furin are differentially expressed in human A549 cells infected with HP avian-origin infA H5N1. Using miR-24 mimics, we demonstrated a robust decrease in both furin mRNA levels and intracellular furin activity in A549 cells. Importantly, pretreatment of A549 cells with miR-24 mimicked these results: a robust decrease of H5N1 infectious virions and a complete block of H5N1 virus spread that was not observed in A549 cells infected with low-pathogenicity swine-origin infA H1N1 virus. Our results suggest that viral-specific downregulation of furin-directed microRNAs such as miR-24 during the life cycle of HP infA viruses may represent a novel regulatory mechanism that governs furin-mediated proteolytic activation of HA0 glycoproteins and production of infectious virions.

  17. T-705 (favipiravir) activity against lethal H5N1 influenza A viruses.

    Science.gov (United States)

    Kiso, Maki; Takahashi, Kazumi; Sakai-Tagawa, Yuko; Shinya, Kyoko; Sakabe, Saori; Le, Quynh Mai; Ozawa, Makoto; Furuta, Yousuke; Kawaoka, Yoshihiro

    2010-01-12

    The neuraminidase inhibitors oseltamivir and zanamivi are used to treat H5N1 influenza. However, oseltamivir-resistant H5N1 viruses have been isolated from oseltamivir-treated patients. Moreover, reassortment between H5N1 viruses and oseltamvir-resistant human H1N1 viruses currently circulating could create oseltamivir-resistant H5N1 viruses, rendering the oseltamivir stockpile obsolete. Therefore, there is a need for unique and effective antivirals to combat H5N1 influenza viruses. The investigational drug T-705 (favipiravir; 6-fluoro-3-hydroxy-2-pyrazinecarboxamide) has antiviral activity against seasonal influenza viruses and a mouse-adapted H5N1 influenza virus derived from a benign duck virus. However, its efficacy against highly pathogenic H5N1 viruses, which are substantially more virulent, remains unclear. Here, we demonstrate that T-705 effectively protects mice from lethal infection with oseltamivir-sensitive or -resistant highly pathogenic H5N1 viruses. Furthermore, our biochemical analysis suggests that T-705 ribofuranosyl triphosphate, an active form of T-705, acts like purines or purine nucleosides in human cells and does not inhibit human DNA synthesis. We conclude that T-705 shows promise as a therapeutic agent for the treatment of highly pathogenic H5N1 influenza patients.

  18. Bovine adenoviral vector-based H5N1 influenza vaccine overcomes exceptionally high levels of pre-existing immunity against human adenovirus.

    Science.gov (United States)

    Singh, Neetu; Pandey, Aseem; Jayashankar, Lakshmi; Mittal, Suresh K

    2008-05-01

    Because of the high prevalence of adenovirus (Ad) infections in humans, it is believed that pre-existing Ad-neutralizing antibodies (vector immunity) may negatively impact the immune response to vaccine antigens when delivered by human Ad (HAd) vectors. In order to evaluate whether bovine Ad subtype 3 (BAd3), a non-HAd vector, can effectively elude high levels of pre-existing vector immunity, naïve and HAd serotype 5 (HAd)-primed mice were immunized with BAd-H5HA [BAd3 vector expressing the hemagglutinin (HA) gene from H5N1 influenza virus]. Even in the presence of very high levels of HAd-specific neutralizing antibody, no significant reductions in HA-specific humoral and cell-mediated immune (CMI) responses were observed in HAd-primed mice immunized with BAd-H5HA. In naïve mice immunized with HAd-H5HA (HAd5 vector expressing H5N1 HA) and boosted with BAd-H5HA, the humoral responses elicited were significantly higher (P BAd-H5HA alone, while the CMI responses were comparable in the groups. This finding underlines the importance of a heterologous prime-boost approach for achieving an enhanced immune response. The immunization of naïve or HAd-primed mice with BAd-H5HA bestowed full protection from morbidity and mortality following a potentially lethal challenge with A/Hong Kong/483/97. These results demonstrate the importance of BAd vectors as an alternate or supplement to HAd vectors for influenza pandemic preparedness.

  19. Pathogenicity of an H5N1 highly pathogenic avian influenza virus isolated in the 2010-2011 winter in Japan to mandarin ducks.

    Science.gov (United States)

    Soda, Kosuke; Usui, Tatsufumi; Uno, Yukiko; Yoneda, Kumiko; Yamaguchi, Tsuyoshi; Ito, Toshihiro

    2013-01-01

    Widespread outbreaks of highly pathogenic avian influenza (HPAI) caused by H5N1 viruses occurred in wild birds in Japan from 2010-2011. Forty out of 63 deceased wild birds belonged to the order Anseriformes, and mandarin duck was one of the dominant species. To estimate the risk of mandarin ducks as a source of virus infection in the environment, we examined the pathogenicity of a causal H5N1 HPAI virus to mandarin ducks. About half of the mandarin ducks died by inoculation with 10(7.0)TCID50 of A/mandarin duck/Miyazaki/22M807-1/2011 (H5N1). Viruses were mainly recovered from the trachea of the ducks sacrificed at three days post inoculation (d.p.i.). Viruses were recovered from the laryngopharyngeal swabs of the observation group until 5 d.p.i. In ducks that died at the late phase of infection, viruses were detected in the systemic organs, such as lung, kidney and colon. Together, these results showed that the H5N1 HPAI viruses, which belonged to clade 2.3.2.1 and are mainly circulating in East Asia, were lethal to mandarin ducks, indicating that mandarin ducks have the potential to disseminate the virus to other bird species. Therefore, wild birds should be kept out of poultry farms to prevent HPAI outbreaks in the future.

  20. Characterization of Clade 2.3.2.1 H5N1 Highly Pathogenic Avian Influenza Viruses Isolated from Wild Birds (Mandarin Duck and Eurasian Eagle Owl in 2010 in Korea

    Directory of Open Access Journals (Sweden)

    Youn-Jeong Lee

    2013-04-01

    Full Text Available Starting in late November 2010, the H5N1 highly pathogenic avian influenza (HPAI virus was isolated from many types of wild ducks and raptors and was subsequently isolated from poultry in Korea. We assessed the genetic and pathogenic properties of the HPAI viruses isolated from a fecal sample from a mandarin duck and a dead Eurasian eagle owl, the most affected wild bird species during the 2010/2011 HPAI outbreak in Korea. These viruses have similar genetic backgrounds and exhibited the highest genetic similarity with recent Eurasian clade 2.3.2.1 HPAI viruses. In animal inoculation experiments, regardless of their originating hosts, the two Korean isolates produced highly pathogenic characteristics in chickens, ducks and mice without pre-adaptation. These results raise concerns about veterinary and public health. Surveillance of wild birds could provide a good early warning signal for possible HPAI infection in poultry as well as in humans.

  1. Characterization of clade 2.3.2.1 H5N1 highly pathogenic avian influenza viruses isolated from wild birds (mandarin duck and Eurasian eagle owl) in 2010 in Korea.

    Science.gov (United States)

    Choi, Jun-Gu; Kang, Hyun-Mi; Jeon, Woo-Jin; Choi, Kang-Seuk; Kim, Kwang-Il; Song, Byung Min; Lee, Hee-Soo; Kim, Jae-Hong; Lee, Youn-Jeong

    2013-04-23

    Starting in late November 2010, the H5N1 highly pathogenic avian influenza (HPAI) virus was isolated from many types of wild ducks and raptors and was subsequently isolated from poultry in Korea. We assessed the genetic and pathogenic properties of the HPAI viruses isolated from a fecal sample from a mandarin duck and a dead Eurasian eagle owl, the most affected wild bird species during the 2010/2011 HPAI outbreak in Korea. These viruses have similar genetic backgrounds and exhibited the highest genetic similarity with recent Eurasian clade 2.3.2.1 HPAI viruses. In animal inoculation experiments, regardless of their originating hosts, the two Korean isolates produced highly pathogenic characteristics in chickens, ducks and mice without pre-adaptation. These results raise concerns about veterinary and public health. Surveillance of wild birds could provide a good early warning signal for possible HPAI infection in poultry as well as in humans.

  2. Impact of education and network for avian influenza H5N1 in human: knowledge, clinical practice, and motivation on medical providers in Vietnam.

    Directory of Open Access Journals (Sweden)

    Toshie Manabe

    Full Text Available BACKGROUND: Knowledge, clinical practice, and professional motivation of medical providers relating to H5N1 infection have an important influence on care for H5N1 patients who require early diagnosis and early medical intervention. METHODS/PRINCIPAL FINDINGS: Novel educational programs including training and workshops for medical providers relating to H5N1 infection in Vietnam were originally created and implemented in 18 provincial hospitals in northern Vietnam between 2008 and 2010. A self-administered, structured questionnaire survey was conducted in 8 provincial hospitals where both educational training and workshops were previously provided. A total of 326 medical providers, including physicians, nurses, and laboratory technicians who attended or did not attend original programs were enrolled in the survey. Knowledge, clinical attitudes and practice (KAP, including motivation surrounding caring for H5N1 patients, were evaluated. The study indicated a high level of knowledge and motivation in all professional groups, with especially high levels in laboratory technicians. Conferences and educational programs were evaluated to be the main scientific information resources for physicians, along with information from colleagues. The chest radiographs and the initiation of antiviral treatment in the absence of RT-PCR result were identified as gaps in education. Factors possibly influencing professional motivation for caring for H5N1 patients included healthcare profession, the hospital where the respondents worked, age group, attendance at original educational programs and at educational programs which were conducted by international health-related organizations. CONCLUSIONS: Educational programs provide high knowledge and motivation for medical providers in Vietnam caring for H5N1 patients. Additional educational programs related to chest radiographs and an initiation of treatment in the absence of RT-PCR are needed. Networking is also necessary

  3. 用SILAC技术研究感染H5N1禽流感病毒后A549肺癌细胞蛋白质组的表达变化%Cellular Proteome Alterations in Highly Pathogenic H5N1 Avian In-fluenza Virus-Infected Human Lung Cell Line A549

    Institute of Scientific and Technical Information of China (English)

    王继峰; 李靖; 康晓平; 吴晓燕; 钱小红; 应万涛; 杨银辉

    2013-01-01

    Objective: To determine the cellular proteome responses of human lung A549 cell lines to the highly pathogenic H5N1 avian influenza virus infection, explore changes of specific molecular pathways and identify the key proteins involved in the infection. Methods: By using stable isotope labeling by amino acids in cell culture (SILAC) method to obtain“heavy”labeled cell lines which were infected with H5N1 virus and“light”labeled cell lines which were not infected, from which the cellular proteins were extracted and mixed in even amounts. Then the peptides derived from the mixed proteins digestion were identified by orthogonal reversed-phase chroma-tography coupled with mass spectroscopy and performed qualitative and quantitative analysis. Results: Of the total 3504 identified proteins and 2469 proteins with quantitative information, 72 were significantly up-regulated, 66 were significantly down-regulated. These proteins were involved in several molecular regulation pathways, including RNA splicesome, interferon inducible pathways, ubiquitin degradation pathway, insulin pathway and so on. Conclu-sion: We successfully established a strategy to explore the virus-host cell interactions with SILAC method. The identification of the key proteins involved in highly pathogenic H5N1 avian influenza virus infection, providedthe theoretical basis forunderstanding the molecular pathogenesis of H5N1 infection.%目的:鉴定高致病性H5N1禽流感病毒感染A549肺癌细胞后,细胞蛋白质组的表达变化,并鉴定特异分子通路的改变及其涉及的关键蛋白质分子。方法:利用稳定同位素标记氨基酸技术(SILAC)标记A549细胞,得到“重标”或“轻标”的A549细胞;“重标”细胞感染高致病性H5N1禽流感病毒24 h后提取细胞总蛋白,与从未感染病毒的“轻标”细胞中提取的总蛋白等量混合,酶解肽段,经正交反相色谱分离后用质谱鉴定,对数据进行定性和定量

  4. Immunogenicity and protective efficacy of a live attenuated H5N1 vaccine in nonhuman primates.

    Directory of Open Access Journals (Sweden)

    Shufang Fan

    2009-05-01

    Full Text Available The continued spread of highly pathogenic H5N1 influenza viruses among poultry and wild birds, together with the emergence of drug-resistant variants and the possibility of human-to-human transmission, has spurred attempts to develop an effective vaccine. Inactivated subvirion or whole-virion H5N1 vaccines have shown promising immunogenicity in clinical trials, but their ability to elicit protective immunity in unprimed human populations remains unknown. A cold-adapted, live attenuated vaccine with the hemagglutinin (HA and neuraminidase (NA genes of an H5N1 virus A/VN/1203/2004 (clade 1 was protective against the pulmonary replication of homologous and heterologous wild-type H5N1 viruses in mice and ferrets. In this study, we used reverse genetics to produce a cold-adapted, live attenuated H5N1 vaccine (AH/AAca that contains HA and NA genes from a recent H5N1 isolate, A/Anhui/2/05 virus (AH/05 (clade 2.3, and the backbone of the cold-adapted influenza H2N2 A/AnnArbor/6/60 virus (AAca. AH/AAca was attenuated in chickens, mice, and monkeys, and it induced robust neutralizing antibody responses as well as HA-specific CD4+ T cell immune responses in rhesus macaques immunized twice intranasally. Importantly, the vaccinated macaques were fully protected from challenge with either the homologous AH/05 virus or a heterologous H5N1 virus, A/bar-headed goose/Qinghai/3/05 (BHG/05; clade 2.2. These results demonstrate for the first time that a cold-adapted H5N1 vaccine can elicit protective immunity against highly pathogenic H5N1 virus infection in a nonhuman primate model and provide a compelling argument for further testing of double immunization with live attenuated H5N1 vaccines in human trials.

  5. Host cytokine responses of pigeons infected with highly pathogenic Thai avian influenza viruses of subtype H5N1 isolated from wild birds.

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    Tsuyoshi Hayashi

    Full Text Available Highly pathogenic avian influenza virus (HPAIV of the H5N1 subtype has been reported to infect pigeons asymptomatically or induce mild symptoms. However, host immune responses of pigeons inoculated with HPAIVs have not been well documented. To assess host responses of pigeons against HPAIV infection, we compared lethality, viral distribution and mRNA expression of immune related genes of pigeons infected with two HPAIVs (A/Pigeon/Thailand/VSMU-7-NPT/2004; Pigeon04 and A/Tree sparrow/Ratchaburi/VSMU-16-RBR/2005; T.sparrow05 isolated from wild birds in Thailand. The survival experiment showed that 25% of pigeons died within 2 weeks after the inoculation of two HPAIVs or medium only, suggesting that these viruses did not cause lethal infection in pigeons. Pigeon04 replicated in the lungs more efficiently than T.sparrow05 and spread to multiple extrapulmonary organs such as the brain, spleen, liver, kidney and rectum on days 2, 5 and 9 post infection. No severe lesion was observed in the lungs infected with Pigeon04 as well as T.sparrow05 throughout the collection periods. Encephalitis was occasionally observed in Pigeon04- or T.sparrow05-infected brain, the severity, however was mostly mild. To analyze the expression of immune-related genes in the infected pigeons, we established a quantitative real-time PCR analysis for 14 genes of pigeons. On day 2 post infection, Pigeon04 induced mRNA expression of Mx1, PKR and OAS to a greater extent than T.sparrow05 in the lungs, however their expressions were not up-regulated concomitantly on day 5 post infection when the peak viral replication was observed. Expressions of TLR3, IFNα, IL6, IL8 and CCL5 in the lungs following infection with the two HPAIVs were low. In sum, Pigeon04 exhibited efficient replication in the lungs compared to T.sparrow05, but did not induce excessive host cytokine expressions. Our study has provided the first insight into host immune responses of pigeons against HPAIV infection.

  6. A non-VH1-69 heterosubtypic neutralizing human monoclonal antibody protects mice against H1N1 and H5N1 viruses.

    Directory of Open Access Journals (Sweden)

    Donata De Marco

    Full Text Available Influenza viruses are among the most important human pathogens and are responsible for annual epidemics and sporadic, potentially devastating pandemics. The humoral immune response plays an important role in the defense against these viruses, providing protection mainly by producing antibodies directed against the hemagglutinin (HA glycoprotein. However, their high genetic variability allows the virus to evade the host immune response and the potential protection offered by seasonal vaccines. The emergence of resistance to antiviral drugs in recent years further limits the options available for the control of influenza. The development of alternative strategies for influenza prophylaxis and therapy is therefore urgently needed. In this study, we describe a human monoclonal antibody (PN-SIA49 that recognizes a highly conserved epitope located on the stem region of the HA and able to neutralize a broad spectrum of influenza viruses belonging to different subtypes (H1, H2 and H5. Furthermore, we describe its protective activity in mice after lethal challenge with H1N1 and H5N1 viruses suggesting a potential application in the treatment of influenza virus infections.

  7. Risk factors of poultry outbreaks and human cases of H5N1 avian influenza virus infection in West Java Province, Indonesia.

    Science.gov (United States)

    Yupiana, Yuni; de Vlas, Sake J; Adnan, Nana M; Richardus, Jan Hendrik

    2010-09-01

    The purpose of this study was to determine the association of potential risk factors to the spread and maintenance of the highly pathogenic avian influenza (HPAI) H5N1 virus in poultry and humans at the district level in West Java Province, Indonesia. The association of demography and environmental risk factors including poultry density, human density, road density, percentage of paddy field, and percentage of swamp, dyke and pond with both HPAI human cases and HPAI outbreaks in poultry were assessed using a descriptive epidemiological design. We also assessed the association of HPAI outbreaks in poultry with HPAI human cases. Poisson regression (generalized linear modeling and generalized estimating equations) was used to analyze the data corrected for over-dispersion. There were 794 HPAI outbreaks in poultry covering 24 of the 25 districts in our study during 2003-2008 and 34 HPAI human cases involving 12 districts during 2005-2008. We found that two risk factors--poultry density and road density--had a statistically significant correlation with the number of HPAI outbreaks in poultry. The number of poultry outbreaks had a negative association with poultry density (29% effect) and a positive association with road density (67% effect). The number of human cases was significantly associated with the number of poultry outbreaks (34% effect), but with none of the other risk factors considered. We conclude that the most effective way to prevent human HPAI cases is to intervene directly in the poultry sector. Our study further suggests that implementing preventive measures in backyard chicken farming and limiting transport of live poultry and their products are promising options to this end. Copyright © 2010 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  8. Cell-Based Systems Biology Analysis of Human AS03-Adjuvanted H5N1 Avian Influenza Vaccine Responses: A Phase I Randomized Controlled Trial

    Science.gov (United States)

    Samir, Parimal; Galassie, Allison; Allos, Tara M.; Niu, Xinnan; Gordy, Laura E.; Creech, C. Buddy; Prasad, Nripesh; Jensen, Travis L.; Hill, Heather; Levy, Shawn E.; Joyce, Sebastian; Link, Andrew J.; Edwards, Kathryn M.

    2017-01-01

    Background Vaccine development for influenza A/H5N1 is an important public health priority, but H5N1 vaccines are less immunogenic than seasonal influenza vaccines. Adjuvant System 03 (AS03) markedly enhances immune responses to H5N1 vaccine antigens, but the underlying molecular mechanisms are incompletely understood. Objective and Methods We compared the safety (primary endpoint), immunogenicity (secondary), gene expression (tertiary) and cytokine responses (exploratory) between AS03-adjuvanted and unadjuvanted inactivated split-virus H5N1 influenza vaccines. In a double-blinded clinical trial, we randomized twenty adults aged 18–49 to receive two doses of either AS03-adjuvanted (n = 10) or unadjuvanted (n = 10) H5N1 vaccine 28 days apart. We used a systems biology approach to characterize and correlate changes in serum cytokines, antibody titers, and gene expression levels in six immune cell types at 1, 3, 7, and 28 days after the first vaccination. Results Both vaccines were well-tolerated. Nine of 10 subjects in the adjuvanted group and 0/10 in the unadjuvanted group exhibited seroprotection (hemagglutination inhibition antibody titer > 1:40) at day 56. Within 24 hours of AS03-adjuvanted vaccination, increased serum levels of IL-6 and IP-10 were noted. Interferon signaling and antigen processing and presentation-related gene responses were induced in dendritic cells, monocytes, and neutrophils. Upregulation of MHC class II antigen presentation-related genes was seen in neutrophils. Three days after AS03-adjuvanted vaccine, upregulation of genes involved in cell cycle and division was detected in NK cells and correlated with serum levels of IP-10. Early upregulation of interferon signaling-related genes was also found to predict seroprotection 56 days after first vaccination. Conclusions Using this cell-based systems approach, novel mechanisms of action for AS03-adjuvanted pandemic influenza vaccination were observed. Trial Registration ClinicalTrials.gov NCT

  9. Preparation and characterization of recombinant Llama VHH-human IgGFc chimeric antibody against H5N1 hemagglutinin from avian influenza virus%羊驼抗H5N1血凝素重链可变区-人IgGFc段嵌合抗体的制备和鉴定

    Institute of Scientific and Technical Information of China (English)

    夏立亮; 吴标; 程亚庭; 蔡家麟; 王颖; 赵国屏

    2012-01-01

    To prepare and characterize llama variable domain of heavy chain of heavy-chain antibody-human IgGlFc (VHH-hFc) chimeric antibody against hemagglutinin from H5N1 avian influenza virus, recombinant expression vector pET-22b-VHH23-hFc was constructed and VHH23-hFc chimeric antibody was expressed in E. coli BL2KDE3) strain by IPTG induction. As VHH23-hFc antibody was accumulated in inclusion bodies, two different refolding methods, dialysis and on-column refolding, were compared for the refolding efficacy and the optimal method was adopted for preparation of VHH23-hFc chimeric antibody. The activity and thermal stability of VHH antibodies were tested by ELISA. By using dialysis refolding procedure, VHH23-hFc chimeric antibody has been obtained with higher yield and good quality. The affinity constant of VHH23-hFc chimeric antibody was 2. 24 × 106 mol/L as determined by ELISA. VHH23-hFc chimeric antibody also displayed good thermal stability. The half-life span of VHH23-hFc chimeric antibody in mice was up to 35 hrs, which is comparable to conventional chimeric antibodies. Taken together, our results indicated that VHH23-hFc chimeric antibody against hemagglutinin derived from H5N1 avian influenza virus has been obtained with high activity, good thermal stability as well as longer half-life span, which provides basis for future functional study both in vitro and in vivo.%本研究旨在制备羊驼抗H5N1禽流感病毒的重链抗体可变区-人Fc段嵌合体抗体制备,对所得嵌合抗体进行制备和功能鉴定,为临床应用奠定基础.用pET-22b表达载体构建抗H5N1禽流感病毒羊驼重链可变区(VHH)-人IgG1Fc嵌合基因,以包涵体形式表达VHH23-hFc嵌合抗体蛋白,采用优化的方法复性后,获得高纯度VHH23-hFc嵌合抗体,用ELISA法鉴定嵌合抗体亲和力、热稳定性和小鼠体内的半衰期.结果显示,透析复性后原核表达的抗H5N1禽流感病毒VHH23-hFc嵌合抗体亲和力为2.24×106 mol/L,具有较好

  10. Domestic pigs have low susceptibility to H5N1 highly pathogenic avian influenza viruses.

    Directory of Open Access Journals (Sweden)

    Aleksandr S Lipatov

    2008-07-01

    Full Text Available Genetic reassortment of H5N1 highly pathogenic avian influenza viruses (HPAI with currently circulating human influenza A strains is one possibility that could lead to efficient human-to-human transmissibility. Domestic pigs which are susceptible to infection with both human and avian influenza A viruses are one of the natural hosts where such reassortment events could occur. Virological, histological and serological features of H5N1 virus infection in pigs were characterized in this study. Two- to three-week-old domestic piglets were intranasally inoculated with 10(6 EID(50 of A/Vietnam/1203/04 (VN/04, A/chicken/Indonesia/7/03 (Ck/Indo/03, A/Whooper swan/Mongolia/244/05 (WS/Mong/05, and A/Muscovy duck/Vietnam/ 209/05 (MDk/VN/05 viruses. Swine H3N2 and H1N1 viruses were studied as a positive control for swine influenza virus infection. The pathogenicity of the H5N1 HPAI viruses was also characterized in mouse and ferret animal models. Intranasal inoculation of pigs with H5N1 viruses or consumption of infected chicken meat did not result in severe disease. Mild weight loss was seen in pigs inoculated with WS/Mong/05, Ck/Indo/03 H5N1 and H1N1 swine influenza viruses. WS/Mong/05, Ck/Indo/03 and VN/04 viruses were detected in nasal swabs of inoculated pigs mainly on days 1 and 3. Titers of H5N1 viruses in nasal swabs were remarkably lower compared with those of swine influenza viruses. Replication of all four H5N1 viruses in pigs was restricted to the respiratory tract, mainly to the lungs. Titers of H5N1 viruses in the lungs were lower than those of swine viruses. WS/Mong/05 virus was isolated from trachea and tonsils, and MDk/VN/05 virus was isolated from nasal turbinate of infected pigs. Histological examination revealed mild to moderate bronchiolitis and multifocal alveolitis in the lungs of pigs infected with H5N1 viruses, while infection with swine influenza viruses resulted in severe tracheobronchitis and bronchointerstitial pneumonia. Pigs

  11. Genetic Analysis of the NS Genes of H5N1Avian Influenza Viruses Isolated from Sewage in Poultry Markets%家禽市场污水来源的H5N1亚型禽流感病毒NS基因分析

    Institute of Scientific and Technical Information of China (English)

    欧新华; 张如胜; 宋克云; 陈田木; 刘如春; 孙边成; 陈法明

    2012-01-01

    对长沙市家禽市场污水来源的H5N1亚型禽流感病毒(Avian influenza viruses,AIV)的非结构蛋白(Nonstructural,NS)基因进行进化和分子特征分析,探讨污水中H5N1病毒的传播风险.9份家禽市场环境污水H5N1亚型AIV标本进行NS基因TA克隆测序,测序结果利用Lasergene和Mega5软件进行氨基酸(amine acid,aa)比对和进化树分析.共得到8个阳性克隆,进化树构建显示8个H5N1的NS基因均属于A亚群,其编码的NS1和NS2蛋白与A亚群代表株(A/chicken/ Hubei/w h/ 1999)aa同源性分别为90.1%~92.5%和91.0%~92.6%,8个H5N1的NS1和NS2 aa之间的同源性分别为93.8%~100.0%和98.4%~100.0%.8个H5N1的NS1蛋白均具有缺失80~84位aa、C末端携带有ESEV的PL基序和第92位aa为E的高致病性分子特征.家禽市场污水来源的H5N1亚型AIV的NS基因具有高致病性的分子特征,这种基因特征表明污水可能传播H5N1病毒.%In order to investigate the transmission risk of H5N1 avian influenza viruses(AIV) from sewage in Changsha poultry markets, the evolution relationship and molecular characteristics of non-structural (NS) genes of H5N1 AIV from sewage were analyzed. Nine H5N1 AIV environmental sewage specimens were collected from Changsha poultry markets. The NS genes were amplifyed by PCR and then sequenced with TA cloning. Amino acid(aa) sequence alignment and phylogenetic tree analysis were conducted by Lasergene and Mega5 software. Eight NS genes TA cloning were constructed successfully. Phylogenetic tree indicated that they were belonged to the allele A subgroup. Aa homology analysis showed 90. 1 % ~ 92. 5% identity in NS1 proteins and 91.0%-92. 6% identity in NS2 proteins compared with reference viruses of the allele A(A/chicken/ Hubei/ w h/ 1999). The homologies of the amino sequences of NS1 and NS2 in this study were 93. 8%- 100. 0% and 98. 4%- 100. 0%, respectively. The C terminal of all eight H5N1 NS1 proteins from sewage in poultry

  12. The special neuraminidase stalk-motif responsible for increased virulence and pathogenesis of H5N1 influenza A virus.

    Directory of Open Access Journals (Sweden)

    Hongbo Zhou

    Full Text Available The variation of highly pathogenic avian influenza H5N1 virus results in gradually increased virulence in poultry, and human cases continue to accumulate. The neuraminidase (NA stalk region of influenza virus varies considerably and may associate with its virulence. The NA stalk region of all N1 subtype influenza A viruses can be divided into six different stalk-motifs, H5N1/2004-like (NA-wt, WSN-like, H5N1/97-like, PR/8-like, H7N1/99-like and H5N1/96-like. The NA-wt is a special NA stalk-motif which was first observed in H5N1 influenza virus in 2000, with a 20-amino acid deletion in the 49(th to 68(th positions of the stalk region. Here we show that there is a gradual increase of the special NA stalk-motif in H5N1 isolates from 2000 to 2007, and notably, the special stalk-motif is observed in all 173 H5N1 human isolates from 2004 to 2007. The recombinant H5N1 virus with the special stalk-motif possesses the highest virulence and pathogenicity in chicken and mice, while the recombinant viruses with the other stalk-motifs display attenuated phenotype. This indicates that the special stalk-motif has contributed to the high virulence and pathogenicity of H5N1 isolates since 2000. The gradually increasing emergence of the special NA stalk-motif in H5N1 isolates, especially in human isolates, deserves attention by all.

  13. Characterization of Clade 2.3.2.1 H5N1 Highly Pathogenic Avian Influenza Viruses Isolated from Wild Birds (Mandarin Duck and Eurasian Eagle Owl) in 2010 in Korea

    OpenAIRE

    Youn-Jeong Lee; Jae-Hong Kim; Hee-Soo Lee; Kwang-Il Kim; Byung Min Song; Woo-Jin Jeon; Kang-Seuk Choi; Hyun-Mi Kang; Jun-Gu Choi

    2013-01-01

    Starting in late November 2010, the H5N1 highly pathogenic avian influenza (HPAI) virus was isolated from many types of wild ducks and raptors and was subsequently isolated from poultry in Korea. We assessed the genetic and pathogenic properties of the HPAI viruses isolated from a fecal sample from a mandarin duck and a dead Eurasian eagle owl, the most affected wild bird species during the 2010/2011 HPAI outbreak in Korea. These viruses have similar genetic backgrounds and exhibited the high...

  14. Evaluation of the antigenic relatedness and cross-protective immunity of the neuraminidase between human influenza A (H1N1) virus and highly pathogenic avian influenza A (H5N1) virus.

    Science.gov (United States)

    Lu, Xiuhua; Liu, Feng; Zeng, Hui; Sheu, Tiffany; Achenbach, Jenna E; Veguilla, Vic; Gubareva, Larisa V; Garten, Rebecca; Smith, Catherine; Yang, Hua; Stevens, James; Xu, Xiyan; Katz, Jacqueline M; Tumpey, Terrence M

    2014-04-01

    To determine the genetic and antigenic relatedness as well as the cross-protective immunity of human H1N1 and avian H5N1 influenza virus neuraminidase (NA), we immunized rabbits with either a baculovirus-expressed recombinant NA from A/Beijing/262/95 (BJ/262) H1N1 or A/Hong Kong/483/97 (HK/483) H5N1 virus. Cross-reactive antibody responses were evaluated by multiple serological assays and cross-protection against H5N1 virus challenge was evaluated in mice. In a neuraminidase inhibition (NI) test, the antisera exhibited substantial inhibition of NA activity of the homologous virus, but failed to inhibit the NA activity of heterologous virus. However, these antisera exhibited low levels of cross-reactivity measured by plaque size reduction, replication inhibition, single radial hemolysis, and ELISA assays. Passive immunization with HK/483 NA-specific antisera significantly reduced virus replication and disease, and afforded almost complete protection against lethal homologous virus challenge in mice. However, passive immunization with BJ/262 (H1N1) NA-specific antisera was ineffective at providing cross-protection against lethal H5N1 virus challenge and only slightly reduced weight loss. Substantial amino acid variation among the NA antigenic sites was observed between BJ/262 and HK/483 virus, which was consistent with the lack of cross-reactive NI activity by the antibody and limited cross-protective immunity in mice. These results show a strong correlation between the lack of cross-protective immunity and low structural similarities of NA from a human seasonal H1N1 virus and an avian H5N1 influenza virus.

  15. Effect of human activated NRAS on replication of delNS1 H5N1 influenza virus in MDCK cells

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    Zou Wei

    2011-05-01

    Full Text Available Abstract Background RAS, coded by ras proto-oncogenes, played an important role in signal transmission to regulate cell growth and differentiation. Host activation of RAS was significant for IFN-sensitive vaccinia virus (delE3L or attenuate influenza virus in unallowable cells. Results Huamn NRAS gene was activated by mutating in codon 61. Then the activation of NRAS was detected by western blot in MDCK cells. The delNS1 H5N1 influenza virus with deletion of NS1 eIF4GI binding domain was weak multiplication in MDCK cells. And the replication of delNS1 virus and expression of IFN-beta and IRF-3 were detected by Real-time PCR in MDCK cells infected with delNS1 virus. It was found that the delNS1 virus had a significant increase in MDCK cells when the NRAS was activated, and yet, expression of IRF-3 and IFN-beta were restrained. Conclusions The study demonstrated that activated NRAS played an important part for delNS1 virus replication in MDCK cells. Activated NRAS might be down-regulating the expression of antiviral cellular factors in delNS1 virus infected cells.

  16. Waterfowl potential as resevoirs of high pathogenic avian influenza H5N1 viruses

    Directory of Open Access Journals (Sweden)

    R Susanti

    2007-06-01

    Full Text Available The high population of waterfowl subsequently with the high case fatality of poultry and people in West Java regency caused by HPAI H5N1 can raise possibility that waterfowl was a natural reservoir. This research aimed to prove that waterfowl in West Java served as reservoir of AI virus (primarily H5N1 and also identify the virus pathotype based on cleavage site of amino acid sequence. Cloacal swab sample was obtained from healthy and unvaccinated waterfowl from Sukabumi and Bogor Regency. Cloacal swab was propagated in 9 days old embryonic chicken eggs. Allantoic fluid was harvested at the 4th day of incubation and then tested for hemagglutination, and positive isolate continued with virus sub-typing using PCR method. H5 gene from H5N1 isolate then sequenced using dideoxy termination method. Multiple alignment of nucleotide sequences were analysed using MEGA-3.1 program. Sub-typing using PCR method indicated the existence of 25 strain H5N1, 16 strain HxN1, 4 strain H5Nx and 9 virus ND. Characterization of cleavage site amino acid sequence indicated that all H5N1 sample were pathogenic with sequence QRERRRKKR (23 sample dan QRESRRKKR (2 sample. Waterfowl was HPAI H5N1 virus reservoir. Asymptomatic infection in waterfowl, but the virus shedding gradually occurred and therefore it became potential source of H5N1 virus infection. Our findings suggest that immediate action is needed to prevent the transmission of highly pathogenic avian influenza viruses from the apparently healthy waterfowl into terrestrial poultry or human.

  17. Recombinant Lactococcus lactis Expressing Haemagglutinin from a Polish Avian H5N1 Isolate and Its Immunological Effect in Preliminary Animal Trials.

    Science.gov (United States)

    Szczepankowska, Agnieszka K; Szatraj, Katarzyna; Sałański, Przemysław; Rózga, Agnieszka; Górecki, Roman K; Bardowski, Jacek K

    2017-01-01

    Lactic acid bacteria (LAB) are Gram-positive, nonpathogenic microorganisms that are gaining much interest as antigen producers for development of live vaccine vectors. Heterologous proteins of different origin have been successfully expressed in various LAB species, including Lactococcus lactis. Recombinant L. lactis strains have been shown to induce specific local and systemic immune responses against various antigens. Our study aimed at constructing a L. lactis strain expressing haemagglutinin of a Polish avian H5H1 influenza isolate and examining its effect on animals. Expression of the cloned H5 gene was achieved using the nisin-controlled gene expression system. Detection of the intracellular H5 antigen produced in L. lactis was performed by Western blot analysis and confirmed using mass spectrometry. The potential of L. lactis recombinant cells to induce an immune response was examined by setting up preliminary immunization trials on chickens and mice. Obtained sera were tested for specific antibodies by ELISA assays. The results of these studies are a promising step toward developing a vaccine against the bird flu using Lactococcus lactis cells as bioreactors for efficient antigen production and delivery to the mucosal surface.

  18. Recombinant Lactococcus lactis Expressing Haemagglutinin from a Polish Avian H5N1 Isolate and Its Immunological Effect in Preliminary Animal Trials

    Directory of Open Access Journals (Sweden)

    Agnieszka K. Szczepankowska

    2017-01-01

    Full Text Available Lactic acid bacteria (LAB are Gram-positive, nonpathogenic microorganisms that are gaining much interest as antigen producers for development of live vaccine vectors. Heterologous proteins of different origin have been successfully expressed in various LAB species, including Lactococcus lactis. Recombinant L. lactis strains have been shown to induce specific local and systemic immune responses against various antigens. Our study aimed at constructing a L. lactis strain expressing haemagglutinin of a Polish avian H5H1 influenza isolate and examining its effect on animals. Expression of the cloned H5 gene was achieved using the nisin-controlled gene expression system. Detection of the intracellular H5 antigen produced in L. lactis was performed by Western blot analysis and confirmed using mass spectrometry. The potential of L. lactis recombinant cells to induce an immune response was examined by setting up preliminary immunization trials on chickens and mice. Obtained sera were tested for specific antibodies by ELISA assays. The results of these studies are a promising step toward developing a vaccine against the bird flu using Lactococcus lactis cells as bioreactors for efficient antigen production and delivery to the mucosal surface.

  19. Recombinant Lactococcus lactis Expressing Haemagglutinin from a Polish Avian H5N1 Isolate and Its Immunological Effect in Preliminary Animal Trials

    Science.gov (United States)

    Szatraj, Katarzyna; Sałański, Przemysław; Rózga, Agnieszka; Górecki, Roman K.; Bardowski, Jacek K.

    2017-01-01

    Lactic acid bacteria (LAB) are Gram-positive, nonpathogenic microorganisms that are gaining much interest as antigen producers for development of live vaccine vectors. Heterologous proteins of different origin have been successfully expressed in various LAB species, including Lactococcus lactis. Recombinant L. lactis strains have been shown to induce specific local and systemic immune responses against various antigens. Our study aimed at constructing a L. lactis strain expressing haemagglutinin of a Polish avian H5H1 influenza isolate and examining its effect on animals. Expression of the cloned H5 gene was achieved using the nisin-controlled gene expression system. Detection of the intracellular H5 antigen produced in L. lactis was performed by Western blot analysis and confirmed using mass spectrometry. The potential of L. lactis recombinant cells to induce an immune response was examined by setting up preliminary immunization trials on chickens and mice. Obtained sera were tested for specific antibodies by ELISA assays. The results of these studies are a promising step toward developing a vaccine against the bird flu using Lactococcus lactis cells as bioreactors for efficient antigen production and delivery to the mucosal surface. PMID:28321412

  20. Antigenic drift in H5N1 avian influenza virus in poultry is driven by mutations in major antigenic sites of the hemagglutinin molecule analogous to those for human influenza virus.

    Science.gov (United States)

    Cattoli, Giovanni; Milani, Adelaide; Temperton, Nigel; Zecchin, Bianca; Buratin, Alessandra; Molesti, Eleonora; Aly, Mona Meherez; Arafa, Abdel; Capua, Ilaria

    2011-09-01

    H5N1 highly pathogenic avian influenza virus has been endemic in poultry in Egypt since 2008, notwithstanding the implementation of mass vaccination and culling of infected birds. Extensive circulation of the virus has resulted in a progressive genetic evolution and an antigenic drift. In poultry, the occurrence of antigenic drift in avian influenza viruses is less well documented and the mechanisms remain to be clarified. To test the hypothesis that H5N1 antigenic drift is driven by mechanisms similar to type A influenza viruses in humans, we generated reassortant viruses, by reverse genetics, that harbored molecular changes identified in genetically divergent viruses circulating in the vaccinated population. Parental and reassortant phenotype viruses were antigenically analyzed by hemagglutination inhibition (HI) test and microneutralization (MN) assay. The results of the study indicate that the antigenic drift of H5N1 in poultry is driven by multiple mutations primarily occurring in major antigenic sites at the receptor binding subdomain, similarly to what has been described for human influenza H1 and H3 subtype viruses.

  1. Spatial distribution and risk factors of highly pathogenic avian influenza (HPAI) H5N1 in China

    Science.gov (United States)

    Martin, Vincent; Pfeiffer, Dirk U.; Zhou, Xiaoyan; Xiao, Xiangming; Prosser, Diann J.; Guo, Fusheng; Gilbert, Marius

    2011-01-01

    Highly pathogenic avian influenza (HPAI) H5N1 was first encountered in 1996 in Guangdong province (China) and started spreading throughout Asia and the western Palearctic in 2004–2006. Compared to several other countries where the HPAI H5N1 distribution has been studied in some detail, little is known about the environmental correlates of the HPAI H5N1 distribution in China. HPAI H5N1 clinical disease outbreaks, and HPAI virus (HPAIV) H5N1 isolated from active risk-based surveillance sampling of domestic poultry (referred to as HPAIV H5N1 surveillance positives in this manuscript) were modeled separately using seven risk variables: chicken, domestic waterfowl population density, proportion of land covered by rice or surface water, cropping intensity, elevation, and human population density. We used bootstrapped logistic regression and boosted regression trees (BRT) with cross-validation to identify the weight of each variable, to assess the predictive power of the models, and to map the distribution of HPAI H5N1 risk. HPAI H5N1 clinical disease outbreak occurrence in domestic poultry was mainly associated with chicken density, human population density, and elevation. In contrast, HPAIV H5N1 infection identified by risk-based surveillance was associated with domestic waterfowl density, human population density, and the proportion of land covered by surface water. Both models had a high explanatory power (mean AUC ranging from 0.864 to 0.967). The map of HPAIV H5N1 risk distribution based on active surveillance data emphasized areas south of the Yangtze River, while the distribution of reported outbreak risk extended further North, where the density of poultry and humans is higher. We quantified the statistical association between HPAI H5N1 outbreak, HPAIV distribution and post-vaccination levels of seropositivity (percentage of effective post-vaccination seroconversion in vaccinated birds) and found that provinces with either outbreaks or HPAIV H5N1 surveillance

  2. Influenza at the animal-human interface: a review of the literature for virological evidence of human infection with swine or avian influenza viruses other than A(H5N1).

    Science.gov (United States)

    Freidl, G S; Meijer, A; de Bruin, E; de Nardi, M; Munoz, O; Capua, I; Breed, A C; Harris, K; Hill, A; Kosmider, R; Banks, J; von Dobschuetz, S; Stark, K; Wieland, B; Stevens, K; van der Werf, S; Enouf, V; van der Meulen, K; Van Reeth, K; Dauphin, G; Koopmans, M

    2014-05-08

    Factors that trigger human infection with animal influenza virus progressing into a pandemic are poorly understood. Within a project developing an evidence-based risk assessment framework for influenza viruses in animals, we conducted a review of the literature for evidence of human infection with animal influenza viruses by diagnostic methods used. The review covering Medline, Embase, SciSearch and CabAbstracts yielded 6,955 articles, of which we retained 89; for influenza A(H5N1) and A(H7N9), the official case counts of t he World Health Organization were used. An additional 30 studies were included by scanning the reference lists. Here, we present the findings for confirmed infections with virological evidence. We found reports of 1,419 naturally infected human cases, of which 648 were associated with avian influenza virus (AIV) A(H5N1), 375 with other AIV subtypes, and 396 with swine influenza virus (SIV). Human cases naturally infected with AIV spanned haemagglutinin subtypes H5, H6, H7, H9 and H10. SIV cases were associated with endemic SIV of H1 and H3 subtype descending from North American and Eurasian SIV lineages and various reassortants thereof. Direct exposure to birds or swine was the most likely source of infection for the cases with available information on exposure.

  3. Adenovirus-based vaccines against avian-origin H5N1 influenza viruses.

    Science.gov (United States)

    He, Biao; Zheng, Bo-jian; Wang, Qian; Du, Lanying; Jiang, Shibo; Lu, Lu

    2015-02-01

    Since 1997, human infection with avian H5N1, having about 60% mortality, has posed a threat to public health. In this review, we describe the epidemiology of H5N1 transmission, advantages and disadvantages of different influenza vaccine types, and characteristics of adenovirus, finally summarizing advances in adenovirus-based H5N1 systemic and mucosal vaccines.

  4. H5N1 avian influenza in China

    Institute of Scientific and Technical Information of China (English)

    CHEN HuaLan

    2009-01-01

    H5N1 highly pathogenic avian influenza virus was first detected in a goose in Guangdong Province of China in 1996. Multiple genotypes of H5N1 viruses have been identified from apparently healthy wa-terfowl since 1999. In the years 2004-2008, over 100 outbreaks in domestic poultry occurred in 23 provinces and caused severe economic damage to the poultry industry in China. Beginning from 2004, a culling plus vaccination strategy has been implemented for the control of epidemics. Since then, over 35420000 poultry have been depopulated, and over 55 billion doses of the different vaccines have been used to control the outbreaks. Although it is logistically impossible to vaccinate every single bird in China due to the large poultry population and the complicated rearing styles, there is no doubt that the increased vaccination coverage has resulted in decreased disease epidemic and environmental virus loading. The experience in China suggests that vaccination has played an important role in the protec-tion of poultry from H5N1 virus infection, the reduction of virus load in the environment, and the pre-vention of H5N1 virus transmission from poultry to humans.

  5. H5N1 avian influenza in China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    H5N1 highly pathogenic avian influenza virus was first detected in a goose in Guangdong Province of China in 1996. Multiple genotypes of H5N1 viruses have been identified from apparently healthy waterfowl since 1999. In the years 2004-2008, over 100 outbreaks in domestic poultry occurred in 23 provinces and caused severe economic damage to the poultry industry in China. Beginning from 2004, a culling plus vaccination strategy has been implemented for the control of epidemics. Since then, over 35420000 poultry have been depopulated, and over 55 billion doses of the different vaccines have been used to control the outbreaks. Although it is logistically impossible to vaccinate every single bird in China due to the large poultry population and the complicated rearing styles, there is no doubt that the increased vaccination coverage has resulted in decreased disease epidemic and environmental virus loading. The experience in China suggests that vaccination has played an important role in the protection of poultry from H5N1 virus infection, the reduction of virus load in the environment, and the prevention of H5N1 virus transmission from poultry to humans.

  6. In Silico Prediction and Experimental Confirmation of HA Residues Conferring Enhanced Human Receptor Specificity of H5N1 Influenza A Viruses

    Science.gov (United States)

    Schmier, Sonja; Mostafa, Ahmed; Haarmann, Thomas; Bannert, Norbert; Ziebuhr, John; Veljkovic, Veljko; Dietrich, Ursula; Pleschka, Stephan

    2015-06-01

    Newly emerging influenza A viruses (IAV) pose a major threat to human health by causing seasonal epidemics and/or pandemics, the latter often facilitated by the lack of pre-existing immunity in the general population. Early recognition of candidate pandemic influenza viruses (CPIV) is of crucial importance for restricting virus transmission and developing appropriate therapeutic and prophylactic strategies including effective vaccines. Often, the pandemic potential of newly emerging IAV is only fully recognized once the virus starts to spread efficiently causing serious disease in humans. Here, we used a novel phylogenetic algorithm based on the informational spectrum method (ISM) to identify potential CPIV by predicting mutations in the viral hemagglutinin (HA) gene that are likely to (differentially) affect critical interactions between the HA protein and target cells from bird and human origin, respectively. Predictions were subsequently validated by generating pseudotyped retrovirus particles and genetically engineered IAV containing these mutations and characterizing potential effects on virus entry and replication in cells expressing human and avian IAV receptors, respectively. Our data suggest that the ISM-based algorithm is suitable to identify CPIV among IAV strains that are circulating in animal hosts and thus may be a new tool for assessing pandemic risks associated with specific strains.

  7. Pre- and Postexposure Use of Human Monoclonal Antibody against H5N1 and H1N1 Influenza Virus in Mice: Viable Alternative to Oseltamivir

    NARCIS (Netherlands)

    Koudstaal, W.; Koldijk, M.H.; Brakenhoff, J.P.J.; Cornelissen, A.H.M.; Weverling, G.J.; Friesen, R.H.E.; Goudsmit, J.

    2009-01-01

    New strategies to prevent and treat influenza virus infections are urgently needed. A recently discovered class of monoclonal antibodies (mAbs) neutralizing an unprecedented spectrum of influenza virus subtypes may have the potential for future use in humans. Here, we assess the efficacies of CR6261

  8. The avian and mammalian host range of highly pathogenic avian H5N1 influenza.

    Science.gov (United States)

    Kaplan, Bryan S; Webby, Richard J

    2013-12-05

    Highly pathogenic H5N1 influenza viruses have been isolated from a number of avian and mammalian species. Despite intensive control measures the number of human and animal cases continues to increase. A more complete understanding of susceptible species and of contributing environmental and molecular factors is crucial if we are to slow the rate of new cases. H5N1 is currently endemic in domestic poultry in only a handful of countries with sporadic and unpredictable spread to other countries. Close contact of terrestrial bird or mammalian species with infected poultry/waterfowl or their biological products is the major route for interspecies transmission. Intra-species transmission of H5N1 in mammals, including humans, has taken place on a limited scale though it remains to be seen if this will change; recent laboratory studies suggest that it is indeed possible. Here we review the avian and mammalian species that are naturally susceptible to H5N1 infection and the molecular factors associated with its expanded host range.

  9. Isolasi dan Identifikasi Virus Avian Influenza Subtipe H5N1 pada Unggas di Pasar Tradisional Semarang

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    Farikhul Ulum

    2013-09-01

    Full Text Available Meningkatnya kasus infeksi virus Avian Influenza (AI subtipe H5N1 atau lebih dikenal dengan flu burung yang menyebabkan kematian pada manusia sangat dikhawatirkan dapat menular dari manusia ke manusia. Penelitian ini bertujuan untuk mendapatkan isolat virus Avian Influenza subtipe H5N1 pada unggas yang diperjualbelikan di pasar tradisional di Semarang. Sebanyak 55 sampel usap kloaka diambil dari unggas sehat dan belum divaksin di 6 pasar tradisional Kota Semarang. Inokulum ditumbuhkan pada telur ayam berembrio specific pathogen free (TAB-SPF umur sembilan hari. Kemudian telur diinkubasikan selama 4 hari. Cairan alantois dipanen dan diuji kemampuannya mengaglutinasi sel darah merah. Cairan alantois yang menunjukkan aktivitas hemaglutinasi, selanjutnya diekstraksi RNA-nya dan diidentifikasi VAI subtipe H5N1 dengan metode Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR menggunakan primer spesifik H5 dan primer N1. Kemudian DNA hasil RT-PCR dianalisis dengan teknik elektroforesis. Hasil penelitian menunjukkan bahwa terdapat 4 isolat positif VAI subtipe H5N1 dengan sebaran 2 isolat dari sampel yang berasal dari pasar Mangkang, 1 isolat dari pasar Rejomulyo dan 1 isolat dari pasar Karimata. Berdasarkan hasil penelitian dan pembahasan dapat disimpulkan bahwa unggas yang diperjualbelikan di pasar tradisional di Kota Semarang ada yang terinfeksi VAI subtipe H5N1.The increasing cases of viral infection of Avian Influenza (AI H5N1 subtype or more commonly known as bird flu that causes death in humans very feared to spread from human to human. The aim of this research was to obtain isolates of Avian Influenza virus (AIV subtype H5N1 that marketable in traditional markets in Semarang. A total of 55 cloacal swab samples taken from healthy and unvaccinated fowl in the 6 traditional market in Semarang. Inoculum was grown in embryonated chicken eggs specific pathogen free (SPF TAB nine days. Then the eggs were incubated for 4 days. Allantoic fluids were

  10. Highly pathogenic influenza A(H5N1 virus survival in complex artificial aquatic biotopes.

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    Viseth Srey Horm

    Full Text Available BACKGROUND: Very little is known regarding the persistence of Highly Pathogenic Avian Influenza (HPAI H5N1 viruses in aquatic environments in tropical countries, although environmental materials have been suggested to play a role as reservoirs and sources of transmission for H5N1 viruses. METHODOLOGY/PRINCIPAL FINDINGS: The survival of HPAI H5N1 viruses in experimental aquatic biotopes (water, mud, aquatic flora and fauna relevant to field conditions in Cambodia was investigated. Artificial aquatic biotopes, including simple ones containing only mud and water, and complex biotopes involving the presence of aquatic flora and fauna, were set up. They were experimentally contaminated with H5N1 virus. The persistence of HPAI H5N1 virus (local avian and human isolates was determined by virus isolation in embryonated chicken eggs and by real-time reverse-polymerase chain reaction. Persistence of infectious virus did not exceed 4 days, and was only identified in rain water. No infectious virus particles were detected in pond and lake water or mud even when high inoculum doses were used. However, viral RNA persisted up to 20 days in rain water and 7 days in pond or lake water. Viral RNA was also detected in mud samples, up to 14 days post-contamination in several cases. Infectious virus and viral RNA was detected in few cases in the aquatic fauna and flora, especially in bivalves and labyrinth fish, although these organisms seemed to be mostly passive carriers of the virus rather than host allowing virus replication. CONCLUSIONS/SIGNIFICANCE: Although several factors for the survival and persistence of HPAI viruses in the environment are still to be elucidated, and are particularly hard to control in laboratory conditions, our results, along with previous data, support the idea that environmental surveillance is of major relevance for avian influenza control programs.

  11. Continual Antigenic Diversification in China Leads to Global Antigenic Complexity of Avian Influenza H5N1 Viruses

    Science.gov (United States)

    Peng, Yousong; Li, Xiaodan; Zhou, Hongbo; Wu, Aiping; Dong, Libo; Zhang, Ye; Gao, Rongbao; Bo, Hong; Yang, Lei; Wang, Dayan; Lin, Xian; Jin, Meilin; Shu, Yuelong; Jiang, Taijiao

    2017-01-01

    The highly pathogenic avian influenza (HPAI) H5N1 virus poses a significant potential threat to human society due to its wide spread and rapid evolution. In this study, we present a comprehensive antigenic map for HPAI H5N1 viruses including 218 newly sequenced isolates from diverse regions of mainland China, by computationally separating almost all HPAI H5N1 viruses into 15 major antigenic clusters (ACs) based on their hemagglutinin sequences. Phylogenetic analysis showed that 12 of these 15 ACs originated in China in a divergent pattern. Further analysis of the dissemination of HPAI H5N1 virus in China identified that the virus’s geographic expansion was co-incident with a significant divergence in antigenicity. Moreover, this antigenic diversification leads to global antigenic complexity, as typified by the recent HPAI H5N1 spread, showing extensive co-circulation and local persistence. This analysis has highlighted the challenge in H5N1 prevention and control that requires different planning strategies even inside China. PMID:28262734

  12. 2005~2006年湖南省人感染高致病性禽流感(H5N1)实验室诊断及病毒基因特性研究%Laboratory Diagnosis and Molecular Characterization of Highly Pathogenic Avian Influenza Virus (H5N1) in Human in Hunan Province in 2005-2006

    Institute of Scientific and Technical Information of China (English)

    黄一伟; 陈碧云; 蓝雨; 周蕾; 舒跃龙; 李梓; 张红; 刘运芝; 温乐英; 李俊华; 高立冬; 赵新生; 李中杰

    2007-01-01

    为了对2005~2006年湖南省2例不明原因肺炎病例进行实验室诊断,确定病因以及对其进行病原学研究,采集病例呼吸道标本和血清标本,对呼吸道标本采用实时荧光定量逆转录聚合酶链式反应(Real-time RT-PCR)和逆转录聚合酶链式反应(RT-PCR)方法检测H5亚型禽流感病毒核酸,对血清标本采用血凝抑制试验检测特异性抗体,并对其中1例死亡病例(病例2)的肺穿刺物标本进行病毒分离,所获毒株予以测序及同源性分析.结果显示,2例病例H5亚型禽流感病毒核酸检测均为阳性,病例1恢复期血清H5N1特异性抗体阳性,并且较急性期血清呈4倍以上增长;病例2急性期血清特异性抗体阴性,2例均为人感染高致病性禽流感病毒(H5N1)确诊病例.从病例2分离得到毒株A/Hunan/1/2006,测序及分子特性分析表明,其8个基因片段均为禽源,且与湖南本地禽类分离的病毒相似,并未与人流感病毒发生基因重组或产生显著变异.

  13. Changes in and shortcomings of control strategies, drug stockpiles, and vaccine development during outbreaks of avian influenza A H5N1, H1N1, and H7N9 among humans.

    Science.gov (United States)

    Mei, Lin; Song, Peipei; Tang, Qi; Shan, Ke; Tobe, Ruoyan Gai; Selotlegeng, Lesego; Ali, Asghar Hammad; Cheng, Yangyang; Xu, Lingzhong

    2013-04-01

    The purpose of this review is to provide a reference for the future prevention and control of emerging infectious diseases by summarizing the control strategies, the status of drugs and vaccines, and shortcomings during three major outbreaks of avian influenza among humans (H5N1 in 2003, H1N1 in 2009, and H7N9 in 2013). Data on and documents regarding the three influenza outbreaks have been reviewed. Results indicated that the response to pandemic influenza outbreaks has improved markedly in terms of control strategies, stockpiles of antivirals, and vaccine development. These improvements also suggest advances in disease surveillance, transparency in reporting, and regional collaboration and cooperation. These trends also foreshadow better prospects for prevention and control of emerging infectious diseases. However, there are shortcomings since strategies failed to focus on high-risk groups, quantitative and measurable results (both direct and indirect) were unclear, and quantitative assessment is still lacking.

  14. Live, attenuated influenza A H5N1 candidate vaccines provide broad cross-protection in mice and ferrets.

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    Amorsolo L Suguitan

    2006-09-01

    Full Text Available BACKGROUND: Recent outbreaks of highly pathogenic influenza A H5N1 viruses in humans and avian species that began in Asia and have spread to other continents underscore an urgent need to develop vaccines that would protect the human population in the event of a pandemic. METHODS AND FINDINGS: Live, attenuated candidate vaccines possessing genes encoding a modified H5 hemagglutinin (HA and a wild-type (wt N1 neuraminidase from influenza A H5N1 viruses isolated in Hong Kong and Vietnam in 1997, 2003, and 2004, and remaining gene segments derived from the cold-adapted (ca influenza A vaccine donor strain, influenza A/Ann Arbor/6/60 ca (H2N2, were generated by reverse genetics. The H5N1 ca vaccine viruses required trypsin for efficient growth in vitro, as predicted by the modification engineered in the gene encoding the HA, and possessed the temperature-sensitive and attenuation phenotypes specified by the internal protein genes of the ca vaccine donor strain. More importantly, the candidate vaccines were immunogenic in mice. Four weeks after receiving a single dose of 10(6 50% tissue culture infectious doses of intranasally administered vaccines, mice were fully protected from lethality following challenge with homologous and antigenically distinct heterologous wt H5N1 viruses from different genetic sublineages (clades 1, 2, and 3 that were isolated in Asia between 1997 and 2005. Four weeks after receiving two doses of the vaccines, mice and ferrets were fully protected against pulmonary replication of homologous and heterologous wt H5N1 viruses. CONCLUSIONS: The promising findings in these preclinical studies of safety, immunogenicity, and efficacy of the H5N1 ca vaccines against antigenically diverse H5N1 vaccines provide support for their careful evaluation in Phase 1 clinical trials in humans.

  15. First introduction of highly pathogenic H5N1 avian influenza A viruses in wild and domestic birds in Denmark, Northern Europe

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    Kabell Susanne

    2007-05-01

    Full Text Available Abstract Background Since 2005 highly pathogenic (HP avian influenza A H5N1 viruses have spread from Asia to Africa and Europe infecting poultry, humans and wild birds. HP H5N1 virus was isolated in Denmark for the first time in March 2006. A total of 44 wild birds were found positive for the HP H5N1 infection. In addition, one case was reported in a backyard poultry flock. Results Full-genome characterisation of nine isolates revealed that the Danish H5N1 viruses were highly similar to German H5N1 isolates in all genes from the same time period. The haemagglutinin gene grouped phylogenetically in H5 clade 2 subclade 2 and closest relatives besides the German isolates were isolates from Croatia in 2005, Nigeria and Niger in 2006 and isolates from Astrakhan in Russia 2006. The German and Danish isolates shared unique substitutions in the NA, PB1 and NS2 proteins. Conclusion The first case of HP H5N1 infection of wild and domestic birds in Denmark was experienced in March 2006. This is the first full genome characterisation of HP H5N1 avian influenza A virus in the Nordic countries. The Danish viruses from this time period have their origin from the wild bird strains from Qinghai in 2005. These viruses may have been introduced to the Northern Europe through unusual migration due to the cold weather in Eastern Europe at that time.

  16. 人感染高致病性禽流感A/H5N1研究现状%Current opinions in highly pathogenic avian influenza A/HSN1 infection in human being

    Institute of Scientific and Technical Information of China (English)

    李佳; 高占成

    2009-01-01

    The avian influenza virus A/HSN1, known to infect only birds previously, broke the species-interface to infect human beings in Hong Kong in 1997. In the 21st century,highly pathogenic avian influenza viruse A/H5N1 is unprecedently spreading to the continents of Asia, Middle East and Africa, involving 15 countries. The mortality is over 60% and this incidence raises universally,concerning about the possibility that such an influenza virus might become the next influenza pandemic strain. This review summarizes the current opinions of avian influenza A/H5N1 with emphasis on virology, epidemiology, pathology and pathogenesis.%1997年,在香港发生禽流感病毒A/HSNl首次突破种间屏障感染人类的病例.21世纪以来,A/HSN1亚型高致病性禽流感疫情的传播范围、规模以及蔓延速度达到了前所未有的程度.世界上许多国家受到冲击,世界范围内病死率超过60%.鉴于目前全球可能出现新一次流感大流行的严峻形势,加强人禽流感的研究迫在眉睫.本文就人禽流感的病毒研究、流行病学特征、病理改变、发病机制等方面进展进行简要综述.

  17. The variable codons of H5N1 avian influenza A virus haemagglutinin genes

    Institute of Scientific and Technical Information of China (English)

    Mark; J.GIBBS; Robert; W.MURPHY

    2008-01-01

    We investigated the selection pressures on the haemagglutinin genes of H5N1 avian influenza viruses using fixed effects likelihood models. We found evidence of positive selection in the sequences from isolates from 1997 to 2007, except viruses from 2000. The haemagglutinin sequences of viruses from southeast Asia, Hong Kong and mainland China were the most polymorphic and had similar nonsyn-onymous profiles. Some sites were positively selected in viruses from most regions and a few of these sites displayed different amino acid patterns. Selection appeared to produce different outcomes in vi-ruses from Europe, Africa and Russia and from different host types. One position was found to be positively selected for human isolates only. Although the functions of some positively selected posi-tions are unknown, our analysis provided evidence of different temporal, spatial and host adaptations for H5N1 avian influenza viruses.

  18. Use of ex vivo and in vitro cultures of the human respiratory tract to study the tropism and host responses of highly pathogenic avian influenza A (H5N1) and other influenza viruses.

    Science.gov (United States)

    Chan, Renee W Y; Chan, Michael C W; Nicholls, John M; Malik Peiris, J S

    2013-12-05

    The tropism of influenza viruses for the human respiratory tract is a key determinant of host-range, and consequently, of pathogenesis and transmission. Insights can be obtained from clinical and autopsy studies of human disease and relevant animal models. Ex vivo cultures of the human respiratory tract and in vitro cultures of primary human cells can provide complementary information provided they are physiologically comparable in relevant characteristics to human tissues in vivo, e.g. virus receptor distribution, state of differentiation. We review different experimental models for their physiological relevance and summarize available data using these cultures in relation to highly pathogenic avian influenza H5N1, in comparison where relevant, with other influenza viruses. Transformed continuous cell-lines often differ in important ways to the corresponding tissues in vivo. The state of differentiation of primary human cells (respiratory epithelium, macrophages) can markedly affect virus tropism and host responses. Ex vivo cultures of human respiratory tissues provide a close resemblance to tissues in vivo and may be used to risk assess animal viruses for pandemic threat. Physiological factors (age, inflammation) can markedly affect virus receptor expression and virus tropism. Taken together with data from clinical studies on infected humans and relevant animal models, data from ex vivo and in vitro cultures of human tissues and cells can provide insights into virus transmission and pathogenesis and may provide understanding that leads to novel therapeutic interventions.

  19. Avian influenza a (H5N1): A preliminary review

    OpenAIRE

    Padhi S.; Panigrahi P; Mahapatra A; Mahapatra S

    2004-01-01

    Humanity has been at the receiving end of many viral diseases since ages. Sudden emergence and re-emergence of new viral diseases in human beings has surprised the medical scientists from time to time. "Avian influenza" or "Bird flu" by H5N1 epidemics is one such surprise. Although many aspects about this disease are clear, there are some dark areas regarding vaccine development that need to be further explored and understood, so as to effectively contain the spread of this disease. The prese...

  20. Avian influenza a (H5N1: A preliminary review

    Directory of Open Access Journals (Sweden)

    Padhi S

    2004-01-01

    Full Text Available Humanity has been at the receiving end of many viral diseases since ages. Sudden emergence and re-emergence of new viral diseases in human beings has surprised the medical scientists from time to time. "Avian influenza" or "Bird flu" by H5N1 epidemics is one such surprise. Although many aspects about this disease are clear, there are some dark areas regarding vaccine development that need to be further explored and understood, so as to effectively contain the spread of this disease. The present article details out almost everything known about this interesting disease along with the review of the recent literature.

  1. Phylogenetic analysis of hemagglutinin and neuraminidase genes of highly pathogenic avian influenza H5N1 Egyptian strains isolated from 2006 to 2008 indicates heterogeneity with multiple distinct sublineages

    Science.gov (United States)

    The Eurasian lineage H5N1 Highly pathogenic avian influenza (HPAI) virus caused widespread outbreaks in Egypt in 2006 and eventually become enzootic in poultry. Although outbreaks have a seasonal pattern with most occurring during the cooler winter months, it remains unclear if this seasonality ref...

  2. Molecular evolution of H5N1 highly pathogenic avian influenza viruses in Bangladesh between 2007 and 2012.

    Science.gov (United States)

    Haque, M E; Giasuddin, M; Chowdhury, E H; Islam, M R

    2014-01-01

    In Bangladesh, highly pathogenic avian influenza (HPAI) virus subtype H5N1 was first detected in February 2007. Since then the virus has become entrenched in poultry farms of Bangladesh. There have so far been seven human cases of H5N1 HPAI infection in Bangladesh with one death. The objective of the present study was to investigate the molecular evolution of H5N1 HPAI viruses during 2007 to 2012. Partial or complete nucleotide sequences of all eight gene segments of two chicken isolates, five gene segments of a duck isolate and the haemagglutinin gene segment of 18 isolates from Bangladesh were established in the present study and subjected to molecular analysis. In addition, full-length sequences of different gene segments of other Bangladeshi H5N1 isolates available in GenBank were included in the analysis. The analysis revealed that the first introduction of clade 2.2 virus in Bangladesh in 2007 was followed by the introduction of clade 2.3.2.1 and 2.3.4 viruses in 2011. However, only clade 2.3.2.1 viruses could be isolated in 2012, indicating progressive replacement of clade 2.2 and 2.3.4 viruses. There has been an event of segment re-assortment between H5N1 and H9N2 viruses in Bangladesh, where H5N1 virus acquired the PB1 gene from a H9N2 virus. Point mutations have accumulated in Bangladeshi isolates over the last 5 years with potential modification of receptor binding site and antigenic sites. Extensive and continuous molecular epidemiological studies are necessary to monitor the evolution of circulating avian influenza viruses in Bangladesh.

  3. Highlight the significance of genetic evolution of H5N1 avian flu

    Institute of Scientific and Technical Information of China (English)

    LU Jia-hai; ZHANG Ding-mei; WANG Guo-ling

    2006-01-01

    @@ Agrowing concern has focused on the recent identification of influenza A H5N1 virus in Asia.Previously thought to infect only wild birds and poultry, H5N1 has now infected humans, cats, pigs,and other mammals in an ongoing outbreak, often with fatal results. According to a report from the World Health Organization (WHO), 217 human H5N1 cases have been confirmed and 123 of them have been fatal as of May 19, 2006.1 But many questions remain unanswered, for example how the H5N1 virus could cross species barriers and acquire the ability to infect humans; when and how the H5N1 virus will transmit effectively between humans and cause an influenza pandemic; and what are the determinants of its high virulence. This article summarizes research progress on the origin of H5N1 virus, factors determining pathogenicity, the contribution of genetic evolution to H5N1 species barrier traversal, human-to-human transmission, and problems in prevention and treatment of H5N1 avian influenza virus.

  4. Influenza A H5N1 immigration is filtered out at some international borders.

    Directory of Open Access Journals (Sweden)

    Robert G Wallace

    Full Text Available BACKGROUND: Geographic spread of highly pathogenic influenza A H5N1, the bird flu strain, appears a necessary condition for accelerating the evolution of a related human-to-human infection. As H5N1 spreads the virus diversifies in response to the variety of socioecological environments encountered, increasing the chance a human infection emerges. Genetic phylogenies have for the most part provided only qualitative evidence that localities differ in H5N1 diversity. For the first time H5N1 variation is quantified across geographic space. METHODOLOGY AND PRINCIPAL FINDINGS: We constructed a statistical phylogeography of 481 H5N1 hemagglutinin genetic sequences from samples collected across 28 Eurasian and African localities through 2006. The MigraPhyla protocol showed southern China was a source of multiple H5N1 strains. Nested clade analysis indicated H5N1 was widely dispersed across southern China by both limited dispersal and long distance colonization. The UniFrac metric, a measure of shared phylogenetic history, grouped H5N1 from Indonesia, Japan, Thailand and Vietnam with those from southeastern Chinese provinces engaged in intensive international trade. Finally, H5N1's accumulative phylogenetic diversity was greatest in southern China and declined beyond. The gradient was interrupted by areas of greater and lesser phylogenetic dispersion, indicating H5N1 migration was restricted at some geopolitical borders. Thailand and Vietnam, just south of China, showed significant phylogenetic clustering, suggesting newly invasive H5N1 strains have been repeatedly filtered out at their northern borders even as both countries suffered recurring outbreaks of endemic strains. In contrast, Japan, while successful in controlling outbreaks, has been subjected to multiple introductions of the virus. CONCLUSIONS: The analysis demonstrates phylogenies can provide local health officials with more than hypotheses about relatedness. Pathogen dispersal, the

  5. The first specific detection of a highly pathogenic avian influenza virus (H5N1) in Ivory Coast.

    Science.gov (United States)

    Couacy-Hymann, E; Danho, T; Keita, D; Bodjo, S C; Kouakou, C; Koffi, Y M; Beudje, F; Tripodi, A; de Benedictis, P; Cattoli, G

    2009-02-01

    The Virology Laboratory of the Central Laboratory of Animal Diseases in Ivory Coast at Bingerville received samples of wild and domestic avian species between February and December 2006. An RT-PCR technique was used to test for avian influenza (AI) and highly pathogenic AI subtype viruses. Among 2125 samples, 16 were type A positive; of which, 12 were later confirmed to be H5N1. Fifteen of these 16 type A positive samples were inoculated into the chorioallantoic cavity of 11-day-old embryonated hens' eggs for virus isolation. Eight produced virus with hemagglutination titres from 1/64 to 1/512. The 4/16 M-RT-PCR positive samples, which were H5N1 negative, were shown to be H7 subtype negative. The diagnostic efficiency of the laboratory for the surveillance of H5N1 in Ivory Coast was demonstrated. The positive cases of H5N1 were from a sparrowhawk (Accipter nisus); live market poultry and in free-range poultry, where the mortality rate was approximately 20% (2/10) and 96.7% (29/30) respectively. Currently, investigations into intensive poultry farms have proved negative for H5N1. No human cases have been reported this time.

  6. Genetic characterization of 2008 reassortant influenza A virus (H5N1, Thailand

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    Wongphatcharachai Manoosak

    2010-09-01

    Full Text Available Abstract In January and November 2008, outbreaks of avian influenza have been reported in 4 provinces of Thailand. Eight Influenza A H5N1 viruses were recovered from these 2008 AI outbreaks and comprehensively characterized and analyzed for nucleotide identity, genetic relatedness, virulence determinants, and possible sites of reassortment. The results show that the 2008 H5N1 viruses displayed genetic drift characteristics (less than 3% genetic differences, as commonly found in influenza A viruses. Based on phylogenetic analysis, clade 1 viruses in Thailand were divided into 3 distinct branches (subclades 1, 1.1 and 1.2. Six out of 8 H5N1 isolates have been identified as reassorted H5N1 viruses, while other isolates belong to an original H5N1 clade. These viruses have undergone inter-lineage reassortment between subclades 1.1 and 1.2 and thus represent new reassorted 2008 H5N1 viruses. The reassorted viruses have acquired gene segments from H5N1, subclade 1.1 (PA, HA, NP and M and subclade 1.2 (PB2, PB1, NA and NS in Thailand. Bootscan analysis of concatenated whole genome sequences of the 2008 H5N1 viruses supported the reassortment sites between subclade 1.1 and 1.2 viruses. Based on estimating of the time of the most recent common ancestors of the 2008 H5N1 viruses, the potential point of genetic reassortment of the viruses could be traced back to 2006. Genetic analysis of the 2008 H5N1 viruses has shown that most virulence determinants in all 8 genes of the viruses have remained unchanged. In summary, two predominant H5N1 lineages were circulating in 2008. The original CUK2-like lineage mainly circulated in central Thailand and the reassorted lineage (subclades 1.1 and 1.2 predominantly circulated in lower-north Thailand. To prevent new reassortment, emphasis should be put on prevention of H5N1 viruses circulating in high risk areas. In addition, surveillance and whole genome sequencing of H5N1 viruses should be routinely performed for

  7. Spatiotemporal structure of molecular evolution of H5N1 highly pathogenic avian influenza viruses in Vietnam.

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    Margaret A Carrel

    Full Text Available BACKGROUND: Vietnam is one of the countries most affected by outbreaks of H5N1 highly pathogenic avian influenza viruses. First identified in Vietnam in poultry in 2001 and in humans in 2004, the virus has since caused 111 cases and 56 deaths in humans. In 2003/2004 H5N1 outbreaks, nearly the entire poultry population of Vietnam was culled. Our earlier study (Wan et al., 2008, PLoS ONE, 3(10: e3462 demonstrated that there have been at least six independent H5N1 introductions into Vietnam and there were nine newly emerged reassortants from 2001 to 2007 in Vietnam. H5N1 viruses in Vietnam cluster distinctly around Hanoi and Ho Chi Minh City. However, the nature of the relationship between genetic divergence and geographic patterns is still unclear. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we hypothesized that genetic distances between H5N1 viruses in Vietnam are correlated with geographic distances, as the result of distinct population and environment patterns along Vietnam's long north to south longitudinal extent. Based on this hypothesis, we combined spatial statistical methods with genetic analytic techniques and explicitly used geographic space to explore genetic evolution of H5N1 highly pathogenic avian influenza viruses at the sub-national scale in Vietnam. Our dataset consisted of 125 influenza viruses (with whole genome sets isolated in Vietnam from 2003 to 2007. Our results document the significant effect of space and time on genetic evolution and the rise of two regional centers of genetic mixing by 2007. These findings give insight into processes underlying viral evolution and suggest that genetic differentiation is associated with the distance between concentrations of human and poultry populations around Hanoi and Ho Chi Minh City. CONCLUSIONS/SIGNIFICANCE: The results show that genetic evolution of H5N1 viruses in Vietnamese domestic poultry is highly correlated with the location and spread of those viruses in geographic space

  8. Evaluation of in vitro cross-reactivity to avian H5N1 and pandemic H1N1 2009 influenza following prime boost regimens of seasonal influenza vaccination in healthy human subjects: a randomised trial.

    Directory of Open Access Journals (Sweden)

    Delia Bethell

    Full Text Available INTRODUCTION: Recent studies have demonstrated that inactivated seasonal influenza vaccines (IIV may elicit production of heterosubtypic antibodies, which can neutralize avian H5N1 virus in a small proportion of subjects. We hypothesized that prime boost regimens of live and inactivated trivalent seasonal influenza vaccines (LAIV and IIV would enhance production of heterosubtypic immunity and provide evidence of cross-protection against other influenza viruses. METHODS: In an open-label study, 26 adult volunteers were randomized to receive one of four vaccine regimens containing two doses of 2009-10 seasonal influenza vaccines administered 8 (±1 weeks apart: 2 doses of LAIV; 2 doses of IIV; LAIV then IIV; IIV then LAIV. Humoral immunity assays for avian H5N1, 2009 pandemic H1N1 (pH1N1, and seasonal vaccine strains were performed on blood collected pre-vaccine and 2 and 4 weeks later. The percentage of cytokine-producing T-cells was compared with baseline 14 days after each dose. RESULTS: Subjects receiving IIV had prompt serological responses to vaccine strains. Two subjects receiving heterologous prime boost regimens had enhanced haemagglutination inhibition (HI and neutralization (NT titres against pH1N1, and one subject against avian H5N1; all three had pre-existing cross-reactive antibodies detected at baseline. Significantly elevated titres to H5N1 and pH1N1 by neuraminidase inhibition (NI assay were observed following LAIV-IIV administration. Both vaccines elicited cross-reactive CD4+ T-cell responses to nucleoprotein of avian H5N1 and pH1N1. All regimens were safe and well tolerated. CONCLUSION: Neither homologous nor heterologous prime boost immunization enhanced serum HI and NT titres to 2009 pH1N1 or avian H5N1 compared to single dose vaccine. However heterologous prime-boost vaccination did lead to in vitro evidence of cross-reactivity by NI; the significance of this finding is unclear. These data support the strategy of

  9. Multivalent HA DNA vaccination protects against highly pathogenic H5N1 avian influenza infection in chickens and mice.

    Directory of Open Access Journals (Sweden)

    Srinivas Rao

    Full Text Available BACKGROUND: Sustained outbreaks of highly pathogenic avian influenza (HPAI H5N1 in avian species increase the risk of reassortment and adaptation to humans. The ability to contain its spread in chickens would reduce this threat and help maintain the capacity for egg-based vaccine production. While vaccines offer the potential to control avian disease, a major concern of current vaccines is their potency and inability to protect against evolving avian influenza viruses. METHODOLOGY / PRINCIPAL FINDINGS: The ability of DNA vaccines encoding hemagglutinin (HA proteins from different HPAI H5N1 serotypes was evaluated for its ability to elicit neutralizing antibodies and to protect against homologous and heterologous HPAI H5N1 strain challenge in mice and chickens after DNA immunization by needle and syringe or with a pressure injection device. These vaccines elicited antibodies that neutralized multiple strains of HPAI H5N1 when given in combinations containing up to 10 HAs. The response was dose-dependent, and breadth was determined by the choice of the influenza virus HA in the vaccine. Monovalent and trivalent HA vaccines were tested first in mice and conferred protection against lethal H5N1 A/Vietnam/1203/2004 challenge 68 weeks after vaccination. In chickens, protection was observed against heterologous strains of HPAI H5N1 after vaccination with a trivalent H5 serotype DNA vaccine with doses as low as 5 microg DNA given twice either by intramuscular needle injection or with a needle-free device. CONCLUSIONS/SIGNIFICANCE: DNA vaccines offer a generic approach to influenza virus immunization applicable to multiple animal species. In addition, the ability to substitute plasmids encoding different strains enables rapid adaptation of the vaccine to newly evolving field isolates.

  10. Acid Stability of the Hemagglutinin Protein Regulates H5N1 Influenza Virus Pathogenicity

    Energy Technology Data Exchange (ETDEWEB)

    DuBois, Rebecca M.; Zaraket, Hassan; Reddivari, Muralidhar; Heath, Richard J.; White, Stephen W.; Russell, Charles J. (Tennessee-HSC); (SJCH)

    2012-12-10

    Highly pathogenic avian influenza viruses of the H5N1 subtype continue to threaten agriculture and human health. Here, we use biochemistry and x-ray crystallography to reveal how amino-acid variations in the hemagglutinin (HA) protein contribute to the pathogenicity of H5N1 influenza virus in chickens. HA proteins from highly pathogenic (HP) A/chicken/Hong Kong/YU562/2001 and moderately pathogenic (MP) A/goose/Hong Kong/437-10/1999 isolates of H5N1 were found to be expressed and cleaved in similar amounts, and both proteins had similar receptor-binding properties. However, amino-acid variations at positions 104 and 115 in the vestigial esterase sub-domain of the HA1 receptor-binding domain (RBD) were found to modulate the pH of HA activation such that the HP and MP HA proteins are activated for membrane fusion at pH 5.7 and 5.3, respectively. In general, an increase in H5N1 pathogenicity in chickens was found to correlate with an increase in the pH of HA activation for mutant and chimeric HA proteins in the observed range of pH 5.2 to 6.0. We determined a crystal structure of the MP HA protein at 2.50 {angstrom} resolution and two structures of HP HA at 2.95 and 3.10 {angstrom} resolution. Residues 104 and 115 that modulate the acid stability of the HA protein are situated at the N- and C-termini of the 110-helix in the vestigial esterase sub-domain, which interacts with the B loop of the HA2 stalk domain. Interactions between the 110-helix and the stalk domain appear to be important in regulating HA protein acid stability, which in turn modulates influenza virus replication and pathogenesis. Overall, an optimal activation pH of the HA protein is found to be necessary for high pathogenicity by H5N1 influenza virus in avian species.

  11. Angiotensin-converting enzyme 2 protects from lethal avian influenza A H5N1 infections.

    Science.gov (United States)

    Zou, Zhen; Yan, Yiwu; Shu, Yuelong; Gao, Rongbao; Sun, Yang; Li, Xiao; Ju, Xiangwu; Liang, Zhu; Liu, Qiang; Zhao, Yan; Guo, Feng; Bai, Tian; Han, Zongsheng; Zhu, Jindong; Zhou, Huandi; Huang, Fengming; Li, Chang; Lu, Huijun; Li, Ning; Li, Dangsheng; Jin, Ningyi; Penninger, Josef M; Jiang, Chengyu

    2014-05-06

    The potential for avian influenza H5N1 outbreaks has increased in recent years. Thus, it is paramount to develop novel strategies to alleviate death rates. Here we show that avian influenza A H5N1-infected patients exhibit markedly increased serum levels of angiotensin II. High serum levels of angiotensin II appear to be linked to the severity and lethality of infection, at least in some patients. In experimental mouse models, infection with highly pathogenic avian influenza A H5N1 virus results in downregulation of angiotensin-converting enzyme 2 (ACE2) expression in the lung and increased serum angiotensin II levels. Genetic inactivation of ACE2 causes severe lung injury in H5N1-challenged mice, confirming a role of ACE2 in H5N1-induced lung pathologies. Administration of recombinant human ACE2 ameliorates avian influenza H5N1 virus-induced lung injury in mice. Our data link H5N1 virus-induced acute lung failure to ACE2 and provide a potential treatment strategy to address future flu pandemics.

  12. Genome Analysis Linking Recent European and African Influenza (H5N1) Viruses

    Science.gov (United States)

    Kingsford, Carl; Cattoli, Giovanni; Spiro, David J.; Janies, Daniel A.; Aly, Mona Mehrez; Brown, Ian H.; Couacy-Hymann, Emmanuel; De Mia, Gian Mario; Dung, Do Huu; Guercio, Annalisa; Joannis, Tony; Ali, Ali Safar Maken; Osmani, Azizullah; Padalino, Iolanda; Saad, Magdi D.; Savić, Vladimir; Sengamalay, Naomi A.; Yingst, Samuel; Zaborsky, Jennifer; Zorman-Rojs, Olga; Ghedin, Elodie; Capua, Ilaria

    2007-01-01

    To better understand the ecology and epidemiology of the highly pathogenic avian influenza virus in its transcontinental spread, we sequenced and analyzed the complete genomes of 36 recent influenza A (H5N1) viruses collected from birds in Europe, northern Africa, and southeastern Asia. These sequences, among the first complete genomes of influenza (H5N1) viruses outside Asia, clearly depict the lineages now infecting wild and domestic birds in Europe and Africa and show the relationships among these isolates and other strains affecting both birds and humans. The isolates fall into 3 distinct lineages, 1 of which contains all known non-Asian isolates. This new Euro-African lineage, which was the cause of several recent (2006) fatal human infections in Egypt and Iraq, has been introduced at least 3 times into the European-African region and has split into 3 distinct, independently evolving sublineages. One isolate provides evidence that 2 of these sublineages have recently reassorted. PMID:17553249

  13. The changing nature of avian influenza A virus (H5N1).

    Science.gov (United States)

    Watanabe, Yohei; Ibrahim, Madiha S; Suzuki, Yasuo; Ikuta, Kazuyoshi

    2012-01-01

    Highly pathogenic avian influenza A virus subtype H5N1 has been endemic in some bird species since its emergence in 1996 and its ecology, genetics and antigenic properties have continued to evolve. This has allowed diverse virus strains to emerge in endemic areas with altered receptor specificity, including a new H5 sublineage with enhanced binding affinity to the human-type receptor. The pandemic potential of H5N1 viruses is alarming and may be increasing. We review here the complex dynamics and changing nature of the H5N1 virus that may contribute to the emergence of pandemic strains.

  14. An Overview of the Highly Pathogenic H5N1 Influenza Virus

    Institute of Scientific and Technical Information of China (English)

    Jingchuan Yin; Shi Liu; Ying Zhu

    2013-01-01

    Since the first human case of H5N1 avian influenza virus infection was reported in 1997,this highly pathogenic virus has infected hundreds of people around the world and resulted in many deaths.The ability of H5N1 to cross species boundaries,and the presence of polymorphisms that enhance virulence,present challenges to developing clear strategies to prevent the pandemic spread of this highly pathogenic avian influenza (HPAI) virus.This review summarizes the current understanding of,and recent research on,the avian influenza H5N1 virus,including transmission,virulence,pathogenesis,clinical characteristics,treatment and prevention.

  15. Avian influenza vaccines against H5N1 'bird flu'.

    Science.gov (United States)

    Li, Chengjun; Bu, Zhigao; Chen, Hualan

    2014-03-01

    H5N1 avian influenza viruses (AIVs) have spread widely to more than 60 countries spanning three continents. To control the disease, vaccination of poultry is implemented in many of the affected countries, especially in those where H5N1 viruses have become enzootic in poultry and wild birds. Recently, considerable progress has been made toward the development of novel avian influenza (AI) vaccines, especially recombinant virus vector vaccines and DNA vaccines. Here, we will discuss the recent advances in vaccine development and use against H5N1 AIV in poultry. Understanding the properties of the available, novel vaccines will allow for the establishment of rational vaccination protocols, which in turn will help the effective control and prevention of H5N1 AI.

  16. Spatio-temporal dynamics of global H5N1 outbreaks match bird migration patterns.

    Science.gov (United States)

    Si, Yali; Skidmore, Andrew K; Wang, Tiejun; de Boer, Willem F; Debba, Pravesh; Toxopeus, Albert G; Li, Lin; Prins, Herbert H T

    2009-11-01

    The global spread of highly pathogenic avian influenza H5N1 in poultry, wild birds and humans, poses a significant pandemic threat and a serious public health risk. An efficient surveillance and disease control system relies on the understanding of the dispersion patterns and spreading mechanisms of the virus. A space-time cluster analysis of H5N1 outbreaks was used to identify spatio-temporal patterns at a global scale and over an extended period of time. Potential mechanisms explaining the spread of the H5N1 virus, and the role of wild birds, were analyzed. Between December 2003 and December 2006, three global epidemic phases of H5N1 influenza were identified. These H5N1 outbreaks showed a clear seasonal pattern, with a high density of outbreaks in winter and early spring (i.e., October to March). In phase I and II only the East Asia Australian flyway was affected. During phase III, the H5N1 viruses started to appear in four other flyways: the Central Asian flyway, the Black Sea Mediterranean flyway, the East Atlantic flyway and the East Africa West Asian flyway. Six disease cluster patterns along these flyways were found to be associated with the seasonal migration of wild birds. The spread of the H5N1 virus, as demonstrated by the space-time clusters, was associated with the patterns of migration of wild birds. Wild birds may therefore play an important role in the spread of H5N1 over long distances. Disease clusters were also detected at sites where wild birds are known to overwinter and at times when migratory birds were present. This leads to the suggestion that wild birds may also be involved in spreading the H5N1 virus over short distances.

  17. Spatio-temporal dynamics of global H5N1 outbreaks match bird migration patterns

    Directory of Open Access Journals (Sweden)

    Yali Si

    2009-11-01

    Full Text Available The global spread of highly pathogenic avian influenza H5N1 in poultry, wild birds and humans, poses a significant pandemic threat and a serious public health risk. An efficient surveillance and disease control system relies on the understanding of the dispersion patterns and spreading mechanisms of the virus. A space-time cluster analysis of H5N1 outbreaks was used to identify spatio-temporal patterns at a global scale and over an extended period of time. Potential mechanisms explaining the spread of the H5N1 virus, and the role of wild birds, were analyzed. Between December 2003 and December 2006, three global epidemic phases of H5N1 influenza were identified. These H5N1 outbreaks showed a clear seasonal pattern, with a high density of outbreaks in winter and early spring (i.e., October to March. In phase I and II only the East Asia Australian flyway was affected. During phase III, the H5N1 viruses started to appear in four other flyways: the Central Asian flyway, the Black Sea Mediterranean flyway, the East Atlantic flyway and the East Africa West Asian flyway. Six disease cluster patterns along these flyways were found to be associated with the seasonal migration of wild birds. The spread of the H5N1 virus, as demonstrated by the space-time clusters, was associated with the patterns of migration of wild birds. Wild birds may therefore play an important role in the spread of H5N1 over long distances. Disease clusters were also detected at sites where wild birds are known to overwinter and at times when migratory birds were present. This leads to the suggestion that wild birds may also be involved in spreading the H5N1 virus over short distances.

  18. Evaluation of In Vitro Cross-Reactivity to Avian H5N1 and Pandemic H1N1 2009 Influenza Following Prime Boost Regimens of Seasonal Influenza Vaccination in Healthy Human Subjects: A Randomised Trial

    Science.gov (United States)

    2013-03-26

    washed, and specific enzyme substrate added. The reactions were stopped with 1 N sulphuric acid . The absorbance was measured at 490 nm. The average A490...California/04/2009 (H1N1) (122 15 mer peptide overlapping by 11 amino acids ) or A/Vietnam/1194/2004 (H5N1) (121 15 mer peptide overlapping by 11 amino... acids ) at a final concentration of each peptide of 1 mg/ml. NP is the main viral protein recognized by cross reactive T cells [12]. All stimulated PBMC

  19. Using knowledge fusion to analyze avian influenza H5N1 in East and Southeast Asia.

    Directory of Open Access Journals (Sweden)

    Erjia Ge

    Full Text Available Highly pathogenic avian influenza (HPAI H5N1, a disease associated with high rates of mortality in infected human populations, poses a serious threat to public health in many parts of the world. This article reports findings from a study aimed at improving our understanding of the spatial pattern of the highly pathogenic avian influenza, H5N1, risk in East-Southeast Asia where the disease is both persistent and devastating. Though many disciplines have made important contributions to our understanding of H5N1, it remains a challenge to integrate knowledge from different disciplines. This study applies genetic analysis that identifies the evolution of the H5N1 virus in space and time, epidemiological analysis that determines socio-ecological factors associated with H5N1 occurrence, and statistical analysis that identifies outbreak clusters, and then applies a methodology to formally integrate the findings of the three sets of methodologies. The present study is novel in two respects. First it makes the initiative attempt to use genetic sequences and space-time data to create a space-time phylogenetic tree to estimate and map the virus' ability to spread. Second, by integrating the results we are able to generate insights into the space-time occurrence and spread of H5N1 that we believe have a higher level of corroboration than is possible when analysis is based on only one methodology. Our research identifies links between the occurrence of H5N1 by area and a set of socio-ecological factors including altitude, population density, poultry density, and the shortest path distances to inland water, coastlines, migrating routes, railways, and roads. This study seeks to lay a solid foundation for the interdisciplinary study of this and other influenza outbreaks. It will provide substantive information for containing H5N1 outbreaks.

  20. Generation and Characterization of Monoclonal Antibodies Specific to Avian Influenza H5N1 Hemagglutinin Protein.

    Science.gov (United States)

    Malik, Ankita; Mallajosyula, V Vamsee Aditya; Mishra, Nripendra Nath; Varadarajan, Raghavan; Gupta, Satish Kumar

    2015-12-01

    Highly pathogenic avian influenza (HPAI) H5N1 virus has in the past breached the species barrier from infected domestic poultry to humans in close contact. Although human-to-human transmission has previously not been reported, HPAI H5N1 virus has pandemic potential owing to gain of function mutation(s) and/or genetic reassortment with human influenza A viruses. Monoclonal antibodies (MAbs) have been used for diagnosis as well as specific therapeutic candidates in several disease conditions including viral infections in humans. In this study, we describe the preliminary characterization of four murine MAbs developed against recombinant hemagglutinin (rHA) protein of avian H5N1 A/turkey/Turkey/1/2005 virus that are either highly specific or broadly reactive against HA from other H5N1 subtype viruses, such as A/Hong Kong/213/03, A/Common magpie/Hong Kong/2256/2006, and A/Barheaded goose/Quinghai/14/2008. The antibody binding is specific to H5N1 HAs, as none of the antibodies bound H1N1, H2N2, H3N2, or B/Brisbane/60/2008 HAs. Out of the four MAbs, one of them (MA-7) also reacted weakly with the rHA protein of H7N9 A/Anhui/1/2013. All four MAbs bound H5 HA (A/turkey/Turkey/1/2005) with high affinity with an equilibrium dissociation constant (KD) ranging between 0.05 and 10.30 nM. One of the MAbs (MA-1) also showed hemagglutination inhibition activity (HI titer; 31.25 μg/mL) against the homologous A/turkey/Turkey/1/2005 H5N1 virus. These antibodies may be useful in developing diagnostic tools for detection of influenza H5N1 virus infection.

  1. Molecular epidemiology of circulating highly pathogenic avian influenza (H5N1) virus in chickens, in Bangladesh, 2007-2010

    DEFF Research Database (Denmark)

    Ahmed, Syed Sayeem Uddin; Themudo, Goncalo Espregueira Cruz; Christensen, Jens Peter

    2012-01-01

    Bangladesh has been severely hit by highly pathogenic avian influenza H5N1 (HPAI-H5N1). However, little is known about the genetic diversity and the evolution of the circulating viruses in Bangladesh. In the present study, we analyzed the hemagglutinin gene of 30 Bangladeshi chicken isolates from...... genetic relatedness and spatial and temporal distances. Neighbor-joining phylogeography revealed that virus circulating in Bangladesh from 2007 through 2010 belonged to clade 2.2. The results suggest that clade 2.2 viruses are firmly entrenched and have probably become endemic in Bangladesh. We detected...... several amino acid substitutions, but they are not indicative of adaptation toward human infection. The Mantel correlation test confirmed significant correlation between genetic distances and temporal distances between the viruses. The Bayesian tree shows that isolates from waves 3 and 4 derived from...

  2. Hemagglutinin pseudotyped lentiviral particles: characterization of a new method for avian H5N1 influenza sero-diagnosis.

    OpenAIRE

    Nefkens, Isabelle; Garcia, Jean-Michel; Ling, Chu Shui; Lagarde, Nadège; Nicholls, John; Tang, Dong Jiang; Peiris, Malik; Buchy, Philippe; Altmeyer, Ralf

    2007-01-01

    BACKGROUND: Highly pathogenic avian influenza (HPAI) H5N1 has spread globally in birds and infected over 270 humans with an apparently high mortality rate. Serologic studies to determine the extent of asymptomatic H5N1 infection in humans and other mammals and to investigate the immunogenicity of current H5N1 vaccine candidates have been hampered by the biosafety requirements needed for H5N1 micro-neutralization tests. OBJECTIVE: Development of a serodiagnostic tool for highly pathogenic infl...

  3. Highly Pathogenic Avian Influenza H5N1 in Mainland China.

    Science.gov (United States)

    Li, Xin-Lou; Liu, Kun; Yao, Hong-Wu; Sun, Ye; Chen, Wan-Jun; Sun, Ruo-Xi; de Vlas, Sake J; Fang, Li-Qun; Cao, Wu-Chun

    2015-05-08

    Highly pathogenic avian influenza (HPAI) H5N1 has posed a significant threat to both humans and birds, and it has spanned large geographic areas and various ecological systems throughout Asia, Europe and Africa, but especially in mainland China. Great efforts in control and prevention of the disease, including universal vaccination campaigns in poultry and active serological and virological surveillance, have been undertaken in mainland China since the beginning of 2006. In this study, we aim to characterize the spatial and temporal patterns of HPAI H5N1, and identify influencing factors favoring the occurrence of HPAI H5N1 outbreaks in poultry in mainland China. Our study shows that HPAI H5N1 outbreaks took place sporadically after vaccination campaigns in poultry, and mostly occurred in the cold season. The positive tests in routine virological surveillance of HPAI H5N1 virus in chicken, duck, goose as well as environmental samples were mapped to display the potential risk distribution of the virus. Southern China had a higher positive rate than northern China, and positive samples were mostly detected from chickens in the north, while the majority were from duck in the south, and a negative correlation with monthly vaccination rates in domestic poultry was found (R = -0.19, p value = 0.005). Multivariate panel logistic regression identified vaccination rate, interaction between distance to the nearest city and national highway, interaction between distance to the nearest lake and wetland, and density of human population, as well as the autoregressive term in space and time as independent risk factors in the occurrence of HPAI H5N1 outbreaks, based on which a predicted risk map of the disease was derived. Our findings could provide new understanding of the distribution and transmission of HPAI H5N1 in mainland China and could be used to inform targeted surveillance and control efforts in both human and poultry populations to reduce the risk of future infections.

  4. Multiple reassortment events among highly pathogenic avian influenza A(H5N1) viruses detected in Bangladesh.

    Science.gov (United States)

    Gerloff, Nancy A; Khan, Salah Uddin; Balish, Amanda; Shanta, Ireen S; Simpson, Natosha; Berman, Lashondra; Haider, Najmul; Poh, Mee Kian; Islam, Ausraful; Gurley, Emily; Hasnat, Md Abdul; Dey, T; Shu, Bo; Emery, Shannon; Lindstrom, Stephen; Haque, Ainul; Klimov, Alexander; Villanueva, Julie; Rahman, Mahmudur; Azziz-Baumgartner, Eduardo; Ziaur Rahman, Md; Luby, Stephen P; Zeidner, Nord; Donis, Ruben O; Sturm-Ramirez, Katharine; Davis, C Todd

    2014-02-01

    In Bangladesh, little is known about the genomic composition and antigenicity of highly pathogenic avian influenza A(H5N1) viruses, their geographic distribution, temporal patterns, or gene flow within the avian host population. Forty highly pathogenic avian influenza A(H5N1) viruses isolated from humans and poultry in Bangladesh between 2008 and 2012 were analyzed by full genome sequencing and antigenic characterization. The analysis included viruses collected from avian hosts and environmental sampling in live bird markets, backyard poultry flocks, outbreak investigations in wild birds or poultry and from three human cases. Phylogenetic analysis indicated that the ancestors of these viruses reassorted (1) with other gene lineages of the same clade, (2) between different clades and (3) with low pathogenicity avian influenza A virus subtypes. Bayesian estimates of the time of most recent common ancestry, combined with geographic information, provided evidence of probable routes and timelines of virus spread into and out of Bangladesh.

  5. Role of Positive Selection Pressure on the Evolution of H5N1 Hemagglutinin

    Institute of Scientific and Technical Information of China (English)

    Venkata R.S.K. Duwuri; Bhargavi Duvvuri; Wilfred R. Cuff; Gillian E. Wu; Jianhong Wu

    2009-01-01

    The surface glycoprotein hemagglutinin (HA) helps the influenza A virus to evade the host immune system by antigenic variation and is a major driving force for viral evolution. In this study, the selection pressure on HA of H5N1 influenza A virus was analyzed using bioinformatics algorithms. Most of the identified positive selection (PS) sites were found to be within or adjacent to epitope sites. Some of the identified PS sites are consistent with previous experimental studies, providing further support to the biological significance of our findings. The highest frequency of PS sites was observed in recent strains isolated during 2005-2007. Phylogenetic analysis was also conducted on HA sequences from various hosts. Viral drift is almost similar in both avian and human species with a progressive trend over the years. Our study reports new mutations in functional regions of HA that might provide markers for vaccine design or can be used to predict isolates of pandemic potential.

  6. Rapid and highly informative diagnostic assay for H5N1 influenza viruses.

    Directory of Open Access Journals (Sweden)

    Nader Pourmand

    Full Text Available A highly discriminative and information-rich diagnostic assay for H5N1 avian influenza would meet immediate patient care needs and provide valuable information for public health interventions, e.g., tracking of new and more dangerous variants by geographic area as well as avian-to-human or human-to-human transmission. In the present study, we have designed a rapid assay based on multilocus nucleic acid sequencing that focuses on the biologically significant regions of the H5N1 hemagglutinin gene. This allows the prediction of viral strain, clade, receptor binding properties, low- or high-pathogenicity cleavage site and glycosylation status. H5 HA genes were selected from nine known high-pathogenicity avian influenza subtype H5N1 viruses, based on their diversity in biologically significant regions of hemagglutinin and/or their ability to cause infection in humans. We devised a consensus pre-programmed pyrosequencing strategy, which may be used as a faster, more accurate alternative to de novo sequencing. The available data suggest that the assay described here is a reliable, rapid, information-rich and cost-effective approach for definitive diagnosis of H5N1 avian influenza. Knowledge of the predicted functional sequences of the HA will enhance H5N1 avian influenza surveillance efforts.

  7. Widespread of H5N1 infections in apparently healthy backyard poultry.

    Science.gov (United States)

    Abozaid, Khaled G A; Aly, Mona M; Abdel-Moneim, Ahmed S; El-Kady, Magdy F

    2016-08-01

    Highly pathogenic avian influenza subtype H5N1 represents a threat to the poultry industry and human health worldwide. Inapparently infected birds are suspected to play an essential role in the spread of avian influenza virus. In the current study, a total of 25,646 samples (16,185 chicken, 4696 ducks, 1633 geese and 3132 turkeys) from apparently healthy birds were screened for the presence of positive samples for H5N1 during 2009-2014. The samples were examined by reverse transcriptase real-time polymerase chain reaction (rRT-PCR) for M, H5 and N1 genes of avian influenza viruses. The results revealed that the HPAI H5N1 existed in an inapparent manner in ducks (4.68 %), geese (4.10 %), chickens (2.48 %) and turkeys (2.29 %). The current finding highlights the serious impact of such type on birds in the epidemiology of H5N1 in birds, animals and humans. It also highlights the existence of another reason other than vaccination that contributes to the widespread of inapparent infection of H5N1 in Egypt.

  8. Greater virulence of highly pathogenic H5N1 influenza virus in cats than in dogs.

    Science.gov (United States)

    Kim, Heui Man; Park, Eun Hye; Yum, Jung; Kim, Hyun Soo; Seo, Sang Heui

    2015-01-01

    Highly pathogenic H5N1 influenza virus continues to infect animals and humans. We compared the infectivity and pathogenesis of H5N1 virus in domestic cats and dogs to find out which animal is more susceptible to H5N1 influenza virus. When cats and dogs were infected with the H5N1 virus, cats suffered from severe outcomes including death, whereas dogs did not show any mortality. Viruses were shed in the nose and rectum of cats and in the nose of dogs. Viruses were detected in brain, lung, kidney, intestine, liver, and serum in the infected cats, but only in the lung in the infected dogs. Genes encoding inflammatory cytokines and chemokines, Toll-like receptors, and apoptotic factors were more highly expressed in the lungs of cats than in those of dogs. Our results suggest that the intensive monitoring of dogs is necessary to prevent human infection by H5N1 influenza virus, since infected dogs may not show clear clinical signs, in contrast to infected cats.

  9. Pathogenesis of avian influenza A (H5N1) viruses in pigs

    Science.gov (United States)

    Background. Genetic reassortment of avian influenza H5N1 viruses with currently circulating human influenza A strains is one possibility that could lead to efficient human-to-human transmissibility. Domestic pigs which are susceptible to infection with both human and avian influenza A viruses are o...

  10. Avian Influenza A(H5N1) Virus in Egypt.

    Science.gov (United States)

    Kayali, Ghazi; Kandeil, Ahmed; El-Shesheny, Rabeh; Kayed, Ahmed S; Maatouq, Asmaa M; Cai, Zhipeng; McKenzie, Pamela P; Webby, Richard J; El Refaey, Samir; Kandeel, Amr; Ali, Mohamed A

    2016-03-01

    In Egypt, avian influenza A subtype H5N1 and H9N2 viruses are enzootic in poultry. The control plan devised by veterinary authorities in Egypt to prevent infections in poultry focused mainly on vaccination and ultimately failed. Recently, widespread H5N1 infections in poultry and a substantial increase in the number of human cases of H5N1 infection were observed. We summarize surveillance data from 2009 through 2014 and show that avian influenza viruses are established in poultry in Egypt and are continuously evolving genetically and antigenically. We also discuss the epidemiology of human infection with avian influenza in Egypt and describe how the true burden of disease is underestimated. We discuss the failures of relying on vaccinating poultry as the sole intervention tool. We conclude by highlighting the key components that need to be included in a new strategy to control avian influenza infections in poultry and humans in Egypt.

  11. Bronchointerstitial pneumonia in guinea pigs following inoculation with H5N1 high pathogenicity avian influenza virus

    Science.gov (United States)

    The H5N1 high pathogenicity avian influenza (HPAI) viruses have caused widespread disease of poultry in Asia, Africa and the Middle East, and sporadic human infections. The guinea pig model has been used to study human H3N2 and H1N1 influenza viruses, but knowledge is lacking on H5N1 HPAI virus inf...

  12. Viral replication rate regulates clinical outcome and CD8 T cell responses during highly pathogenic H5N1 influenza virus infection in mice.

    Directory of Open Access Journals (Sweden)

    Yasuko Hatta

    2010-10-01

    Full Text Available Since the first recorded infection of humans with H5N1 viruses of avian origin in 1997, sporadic human infections continue to occur with a staggering mortality rate of >60%. Although sustained human-to-human transmission has not occurred yet, there is a growing concern that these H5N1 viruses might acquire this trait and raise the specter of a pandemic. Despite progress in deciphering viral determinants of pathogenicity, we still lack crucial information on virus/immune system interactions pertaining to severe disease and high mortality associated with human H5N1 influenza virus infections. Using two human isolates of H5N1 viruses that differ in their pathogenicity in mice, we have defined mechanistic links among the rate of viral replication, mortality, CD8 T cell responses, and immunopathology. The extreme pathogenicity of H5N1 viruses was directly linked to the ability of the virus to replicate rapidly, and swiftly attain high steady-state titers in the lungs within 48 hours after infection. The remarkably high replication rate of the highly pathogenic H5N1 virus did not prevent the induction of IFN-β or activation of CD8 T cells, but the CD8 T cell response was ineffective in controlling viral replication in the lungs and CD8 T cell deficiency did not affect viral titers or mortality. Additionally, BIM deficiency ameliorated lung pathology and inhibited T cell apoptosis without affecting survival of mice. Therefore, rapidly replicating, highly lethal H5N1 viruses could simply outpace and overwhelm the adaptive immune responses, and kill the host by direct cytopathic effects. However, therapeutic suppression of early viral replication and the associated enhancement of CD8 T cell responses improved the survival of mice following a lethal H5N1 infection. These findings suggest that suppression of early H5N1 virus replication is key to the programming of an effective host response, which has implications in treatment of this infection in humans.

  13. Viral replication rate regulates clinical outcome and CD8 T cell responses during highly pathogenic H5N1 influenza virus infection in mice.

    Science.gov (United States)

    Hatta, Yasuko; Hershberger, Karen; Shinya, Kyoko; Proll, Sean C; Dubielzig, Richard R; Hatta, Masato; Katze, Michael G; Kawaoka, Yoshihiro; Suresh, M

    2010-10-07

    Since the first recorded infection of humans with H5N1 viruses of avian origin in 1997, sporadic human infections continue to occur with a staggering mortality rate of >60%. Although sustained human-to-human transmission has not occurred yet, there is a growing concern that these H5N1 viruses might acquire this trait and raise the specter of a pandemic. Despite progress in deciphering viral determinants of pathogenicity, we still lack crucial information on virus/immune system interactions pertaining to severe disease and high mortality associated with human H5N1 influenza virus infections. Using two human isolates of H5N1 viruses that differ in their pathogenicity in mice, we have defined mechanistic links among the rate of viral replication, mortality, CD8 T cell responses, and immunopathology. The extreme pathogenicity of H5N1 viruses was directly linked to the ability of the virus to replicate rapidly, and swiftly attain high steady-state titers in the lungs within 48 hours after infection. The remarkably high replication rate of the highly pathogenic H5N1 virus did not prevent the induction of IFN-β or activation of CD8 T cells, but the CD8 T cell response was ineffective in controlling viral replication in the lungs and CD8 T cell deficiency did not affect viral titers or mortality. Additionally, BIM deficiency ameliorated lung pathology and inhibited T cell apoptosis without affecting survival of mice. Therefore, rapidly replicating, highly lethal H5N1 viruses could simply outpace and overwhelm the adaptive immune responses, and kill the host by direct cytopathic effects. However, therapeutic suppression of early viral replication and the associated enhancement of CD8 T cell responses improved the survival of mice following a lethal H5N1 infection. These findings suggest that suppression of early H5N1 virus replication is key to the programming of an effective host response, which has implications in treatment of this infection in humans.

  14. Emergence of H5N1 avian influenza viruses with reduced sensitivity to neuraminidase inhibitors and novel reassortants in Lao People's Democratic Republic

    Science.gov (United States)

    Boltz, David A.; Douangngeun, Bounlom; Phommachanh, Phouvong; Sinthasak, Settha; Mondry, Ricarda; Obert, Caroline; Seiler, Patrick; Keating, Rachael; Suzuki, Yasuo; Hiramatsu, Hiroaki; Govorkova, Elena A.; Webster, Robert G.

    2010-01-01

    Pandemic influenza viruses can emerge through continuous evolution and the acquisition of specific mutations or through reassortment. This study assessed the pandemic potential of H5N1 viruses isolated from poultry outbreaks occurring from July 2006 to September 2008 in the Lao People's Democratic Republic (PDR). We analyzed 29 viruses isolated from chickens and ducks and two from fatal human cases in 2007. Prior to 2008, all H5N1 isolates in Lao PDR were from clade 2.3.4; however, clade 2.3.2 was introduced in September 2008. Of greatest concern was the circulation of three isolates that showed reduced sensitivity to the neuraminidase (NA) inhibitor oseltamivir in an enzyme inhibition assay, each with different NA mutations – V116A, I222L and K150N, and a previously unreported S246N mutation. In addition, six isolates had an S31N mutation in the M2 protein, which conferred resistance to amantadine not previously reported in clade 2.3.4 viruses. Two H5N1 reassortants were isolated whose polymerase genes, PB1 and PB2, were homologous to those of Eurasian viruses giving rise to a novel H5N1 genotype, genotype P. All H5N1 viruses retained avian-like receptor specificity, but four had altered affinities for α2,3-linked sialic acid. This study shows that, in a genetically similar population of H5N1 viruses in Lao PDR, mutants emerged with natural resistance to antivirals and altered affinities for α2,3-linked sialic acids, together with reassortants with polymerase genes homologous to Eurasian viruses. These changes may contribute to the emergence of a pandemic influenza strain and are critical in devising surveillance strategies. PMID:20016036

  15. A SPR aptasensor for detection of avian influenza virus H5N1.

    Science.gov (United States)

    Bai, Hua; Wang, Ronghui; Hargis, Billy; Lu, Huaguang; Li, Yanbin

    2012-01-01

    Rapid and specific detection of avian influenza virus (AIV) is urgently needed due to the concerns over the potential outbreaks of highly pathogenic H5N1 influenza in animals and humans. Aptamers are artificial oligonucleic acids that can bind specific target molecules, and show comparable affinity for target viruses and better thermal stability than monoclonal antibodies. The objective of this research was to use a DNA-aptamer as the specific recognition element in a portable Surface Plasmon Resonance (SPR) biosensor for rapid detection of AIV H5N1 in poultry swab samples. A SPR biosensor was fabricated using selected aptamers that were biotinylated and then immobilized on the sensor gold surface coated with streptavidin via streptavidin-biotin binding. The immobilized aptamers captured AIV H5N1 in a sample solution, which caused an increase in the refraction index (RI). After optimizing the streptavidin and aptamer parameters, the results showed that the RI value was linearly related (R(2) = 0.99) to the concentration of AIV in the range of 0.128 to 1.28 HAU. Negligible signal (H5N1) was observed from six non-target AIV subtypes. The AIV H5N1 in poultry swab samples with concentrations of 0.128 to 12.8 HAU could be detected using this aptasensor in 1.5 h.

  16. A SPR Aptasensor for Detection of Avian Influenza Virus H5N1

    Directory of Open Access Journals (Sweden)

    Huaguang Lu

    2012-09-01

    Full Text Available Rapid and specific detection of avian influenza virus (AIV is urgently needed due to the concerns over the potential outbreaks of highly pathogenic H5N1 influenza in animals and humans. Aptamers are artificial oligonucleic acids that can bind specific target molecules, and show comparable affinity for target viruses and better thermal stability than monoclonal antibodies. The objective of this research was to use a DNA-aptamer as the specific recognition element in a portable Surface Plasmon Resonance (SPR biosensor for rapid detection of AIV H5N1 in poultry swab samples. A SPR biosensor was fabricated using selected aptamers that were biotinylated and then immobilized on the sensor gold surface coated with streptavidin via streptavidin-biotin binding. The immobilized aptamers captured AIV H5N1 in a sample solution, which caused an increase in the refraction index (RI. After optimizing the streptavidin and aptamer parameters, the results showed that the RI value was linearly related (R2 = 0.99 to the concentration of AIV in the range of 0.128 to 1.28 HAU. Negligible signal ( < 4% of H5N1 was observed from six non-target AIV subtypes. The AIV H5N1 in poultry swab samples with concentrations of 0.128 to 12.8 HAU could be detected using this aptasensor in 1.5 h.

  17. Global distribution patterns of highly pathogenic H5N1 avian influenza: environmental vs. socioeconomic factors.

    Science.gov (United States)

    Chen, Youhua; Chen, You-Fang

    2014-01-01

    In this report, we quantitatively analyzed the essential ecological factors that were strongly correlated with the global outbreak of highly pathogenic H5N1 avian influenza. The ecological niche modeling (ENM) was used to reveal the potential outbreak hotspots of H5N1. A two-step modeling procedure has been proposed: we first used BioClim model to obtain the coarse suitable areas of H5N1, and then those suitable areas with very high probabilities were retained as the inputs of multiple-variable autologistic regression analysis (MAR) for model refinement. MAR was implemented taking spatial autocorrelation into account. The final performance of ENM was evaluated using the areas under the curve (AUC) of receiver-operating characteristic. In addition, principal component analysis (PCA) was employed to reveal the most important variables and relevant ecological gradients of H5N1 outbreak. Niche visualization was used to identify potential spreading trend of H5N1 along important ecological gradients. For the first time, we combined socioeconomic and environmental variables as joint predictors in developing ecological niche modeling. Environmental variables represented the natural element related to H5N1 outbreak, whereas socioeconomic ones represented the anthropogenic element. Our results indicated that: (1) the high-risk hotspots are mainly located in temperate zones (indicated by ENM)-correspondingly, we argued that the "ecoregions hypothesis" was reasonable to some extent; (2) evaporation, humidity, human population density, livestock population density were the first four important factors (in descending order) that were associated with the H5N1 global outbreak (indicated by PCA); (3) influenza had a tendency to expand into areas with low evaporation (indicated by niche visualization). In conclusion, our study substantiates that both the environmental and socioeconomic variables jointly determined the global spreading trend of H5N1, but environmental variables

  18. Tapak Perlekatan Reseptor Virus Flu Burung yang Diisolasi dari Berbagai Unggas Sejak tahun 2003 sampai 2008 (RECEPTOR BINDING SITE OF AVIAN INFLUENZA VIRUS H5N1 ISOLATED FROM VARIOUS POULTRIES SINCE 2003 TO 2008

    Directory of Open Access Journals (Sweden)

    Michael Haryadi Wibowo

    2014-08-01

    Full Text Available Avian Influenza (AI is an infectious disease in poultry, caused by type A of avian influenza virus(AIV, in the family of Orthomyxoviridae. Almost all birds’ species are sensitive to the AI. Beside theability to infect various species of poultry. AIV type A has a wide range of host including all bird species,mammals, dan human. Today some scientists reported that the cases of AI in mammals, including humansare increasing. This condition suggests that the AI virus circulated in the field may have some mutationsin the amino acid determinants responsible receptor binding site (RBS. A research was therefore designedto investigate the molecular level of HA gen fragment responsible for receptor binding site of AIV isolatedfrom various poultry since 2003 to 2008. Molecular characterization was based on the amplification ofreceptor binding site of HA gene by reverse transcriptase polymerase chain reaction (RT-PCR. All RTPCRof HA gene positive products were sequenced to determine the nucleotide composition at the targetedfragment. Sequences yielded were analyzed by program Mega 4.0 versions, including multiple alignment,deductive amino acid prediction, and establishment of phylogenetic tree. The results show that all AIVisolates could be determined of some conserved amino acids residues responsible for RBS which indicatethe binding preference of avian like receptor, sialic acid ? 2, 3 galactose except isolate A/Layer/Jabar/MHW-RBS-02/2008 which could be found a deletion of amino acid at position of 129 dan mutation of 151isoleucine into threonine. Phylogenetic study showed that clustering of AIV did not base on species of birdor geographic origin of AI viruses which were studied.

  19. Cross-protection against lethal H5N1 challenge ferrets with an adjuvanted pandemic influenza vaccine

    NARCIS (Netherlands)

    B. Baras (Benoît); K.J. Stittelaar (Koert); J.H. Simon (James); R.J.M.M. Thoolen (Robert); S.P. Mossman (Sally); F.H. Pistoor (Frank); G. van Amerongen (Geert); M.A. Wettendorff (Martine); E. Hanon (Emmanuel); A.D.M.E. Osterhaus (Albert)

    2008-01-01

    textabstractBackground. Unprecedented spread between birds and mammals of highly pathogenic avian influenza viruses (HPAI) of the H5N1 subtype has resulted in hundreds of human infections with a high fatality rate. This has highlighted the urgent need for the development of H5N1 vaccines that can be

  20. Retrospective space-time analysis of H5N1 Avian Influenza emergence in Thailand

    OpenAIRE

    Shanmugasundaram Jothiganesh; Gonzalez Jean-Paul; Souris Marc; Corvest Victoria; Kittayapong Pattamaporn

    2010-01-01

    Abstract Background The highly pathogenic avian influenza (HPAI) H5N1 virus remains a worldwide threat to human and animal health, while the mechanisms explaining its epizootic emergence and re-emergence in poultry are largely unknown. Data from Thailand, a country that experienced significant epidemics in poultry and has recorded suspicious cases of HPAI on a daily basis since 2004, are used here to study the process of emergence. A spatial approach is employed to describe all HPAI H5N1 viru...

  1. Genetic diversity and phylogenetic analysis of highly pathogenic avian influenza (HPAI) H5N1 viruses circulating in Bangladesh from 2007-2011.

    Science.gov (United States)

    Mondal, S P; Balasuriya, U B R; Yamage, M

    2013-12-01

    Highly pathogenic avian influenza (HPAI) H5N1 virus has been endemic in Bangladesh since its first isolation in February 2007. Phylogenetic analysis of the haemagglutinin (HA) gene of HPAI H5N1 viruses demonstrated that 25 Bangladeshi isolates including two human isolates from 2007-2011 along with some isolates from neighbouring Asian countries (India, Bhutan, Myanmar, Nepal, China and Vietnam) segregate into two distinct clades (2.2 and 2.3). There was clear evidence of introduction of clade 2.3.2 and 2.3.4 viruses in 2011 in addition to clade 2.2 viruses that had been in circulation in Bangladesh since 2007. The data clearly demonstrated the movement of H5N1 strains between Asian countries included in this study due to migration of wild birds and/or illegal movement of poultry across borders. Interestingly, the two human isolates were closely related to the clade 2.2 Bangladeshi chicken isolates indicating that they have originated from chickens. Furthermore, comparative amino acid sequence analysis revealed several substitutions (including 189R>K and 282I>V) in HA protein of some clade 2.2 Bangladeshi viruses including the human isolates, suggesting there was antigenic drift in clade 2.2.3 viruses that were circulating between 2008 and 2011. Overall, the data imply genetic diversity among circulating viruses and multiple introductions of H5N1 viruses with an increased risk of human infections in Bangladesh, and establishment of H5N1 virus in wild and domestic bird populations, which demands active surveillance. © 2013 Blackwell Verlag GmbH.

  2. Southward autumn migration of waterfowl facilitates cross-continental transmission of the highly pathogenic avian influenza H5N1 virus

    NARCIS (Netherlands)

    Xu, Yanjie; Gong, Peng; Wielstra, Ben; Si, Yali

    2016-01-01

    The highly pathogenic avian influenza subtype H5N1 (HPAI H5N1) is a worldwide zoonotic infectious disease, threatening humans, poultry and wild birds. The role of wild birds in the spread of HPAI H5N1 has previously been investigated by comparing disease spread patterns with bird migration routes

  3. Evolution of highly pathogenic avian influenza H5N1 viruses in Egypt indicating progressive adaptation

    Science.gov (United States)

    Highly pathogenic avian influenza (HPAI) virus of the H5N1 subtype was first diagnosed in poultry in Egypt in 2006, and since then the disease became enzootic in poultry throughout the country affecting the poultry industry and village poultry as well as infecting humans. Vaccination has been used ...

  4. Highly pathogenic avian influenza H5N1 in Mainland China

    NARCIS (Netherlands)

    X.-L. Li (Xin-Lou); K. Liu (Kun); H.-W. Yao (Hong-Wu); Y. Sun (Ye); W.-J. Chen (Wan-Jun); R.-X. Sun (Ruo-Xi); S.J. de Vlas (Sake); L.Q. Fang; W. Cao (W.)

    2015-01-01

    textabstractHighly pathogenic avian influenza (HPAI) H5N1 has posed a significant threat to both humans and birds, and it has spanned large geographic areas and various ecological systems throughout Asia, Europe and Africa, but especially in mainland China. Great efforts in control and prevention of

  5. Knowledge discovery from mining the association between H5N1 outbreaks and environmental factors

    NARCIS (Netherlands)

    Si, Y.; Wang, T.; Skidmore, A.K.; Prins, H.H.T.

    2010-01-01

    The global spread of highly pathogenic avian influenza H5N1 in poultry, wild birds and humans, poses a significant panzootic threat and a serious public health risk. An efficient surveillance and disease control system requires a deep understanding of their spread mechanisms, including environmental

  6. Environmental factors contributing to the spread of H5N1 avian influenza in mainland China

    NARCIS (Netherlands)

    L.Q. Fang; S.J. de Vlas (Sake); S. Liang (Song); C.W.N. Looman (Caspar); P. Gong (Peng); B. Xu (Bing); L. Yan (Lei); H. Yang (Honghui); J.H. Richardus (Jan Hendrik); W.C. Cao (Wu Chun)

    2008-01-01

    textabstractBackground: Since late 2003, highly pathogenic avian influenza (HPAI) outbreaks caused by infection with H5N1 virus has led to the deaths of millions of poultry and more than 10 thousands of wild birds, and as of 18-March 2008, at least 373 laboratory-confirmed human infections with 236

  7. Spatial and temporal patterns of global H5N1 outbreaks

    CSIR Research Space (South Africa)

    Si, YL

    2008-07-01

    Full Text Available The global spread of highly pathogenic avian influenza (H5N1) in wild birds and poultry is considered a significant pandemic threat. Furthermore, human infections resulting from direct contact with infected birds/ poultry pose a serious public...

  8. Characterization of avian influenza H5N1 virosome

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    Chatchai Sarachai

    2014-04-01

    Full Text Available The purpose of this study was to prepare and characterize virosome containing envelope proteins of the avian influenza (H5N1 virus. The virosome was prepared by the solubilization of virus with octaethyleneglycol mono (n-dodecyl ether (C12E8 followed by detergent removal with SM2 Bio-Beads. Biochemical analysis by SDS-PAGE and western blotting, indicated that avian influenza H5N1 virosome had similar characteristics to the parent virus and contained both the hemagglutinin (HA, 60-75 kDa and neuraminidase (NA, 220 kDa protein, with preserved biological activity, such as hemagglutination activity. The virosome structure was analyzed by negative stained transmission electron microscope (TEM demonstrated that the spherical shapes of vesicles with surface glycoprotein spikes were harbored. In conclusion, the biophysical properties of the virosome were similar to the parent virus, and the use of octaethyleneglycol mono (n-dodecyl ether to solubilize viral membrane, followed by removal of detergent using polymer beads adsorption (Bio-Beads SM2 was the preferable method for obtaining avian influenza virosome. The outcome of this study might be useful for further development veterinary virus vaccines.

  9. Molecular characteristic and pathogenicity of Indonesian H5N1 clade 2.3.2 viruses

    Directory of Open Access Journals (Sweden)

    Dharmayanti NLPI

    2013-06-01

    Full Text Available The outbreak of disease in late 2012 in Indonesia caused high duck mortality. The agent of the disease was identified as H5N1 clade 2.3.2. The disease caused economic loss to the Indonesian duck farmer. The clade 2.3.2 of H5N1 virus has not previously been identified, so this study was conducted to characterize 4 of H5N1 clade 2.3.2 viruses by DNA sequencing in eight genes segment virus namely HA, NA, NS, M, PB1, PB2, PA and NP. The pathogenicity test of clade 2.3.2 viruses in ducks was compared to clade 2.1.3 viruses which predominat circulating in Indonesia. Results of phylogenetic tree analysis showed that the four of clade 2.3.2 viruses isolated in 2012 was the new introduced virus from abroad. Further analysis showed eight genes were in one group with the clade 2.3.2 viruses, especially those from VietNam and did not belong to Indonesia viruses group. The pathogenicity test in ducks showed that virus H5N1 clade 2.3.2 and clade 2.1.3 have similar clinical symptoms and pathogenicity and cause death in 75% of ducks on days 3-6 after infection.

  10. H5N1 surveillance in migratory birds in Java, Indonesia.

    Science.gov (United States)

    Stoops, Arthur C; Barbara, Katie A; Indrawan, Mochamad; Ibrahim, Ima N; Petrus, Wicaksana B; Wijaya, Susan; Farzeli, Arik; Antonjaya, Ungke; Sin, Lim W; Hidayatullah, N; Kristanto, Ige; Tampubolon, A M; Purnama, S; Supriatna, Adam; Burgess, Timothy H; Williams, Maya; Putnam, Shannon D; Tobias, Steve; Blair, Patrick J

    2009-12-01

    We sought to elucidate the role of migratory birds in transmission of H5N1 in an enzoonotic area. Resident, captive, and migratory birds were sampled at five sites in Java, Indonesia. Mist nets were used to trap birds. Birds were identified to species. RNA was extracted from swabs and reverse transcriptase polymerase chain reaction (RT-PCR) conducted for the HA and M genes of H5N1. Antibodies were detected by enzyme-linked immunosorbent assay and hemagglutination inhibition test. Between October 2006 and September 2007, a total of 4,067 captive, resident, and migratory birds comprising 98 species in 23 genera were sampled. The most commonly collected birds were the common sandpiper (6% of total), striated heron (3%), and the domestic chicken (14%). The overall prevalence of H5N1 antibodies was 5.3%. A significantly higher percentage of captive birds (16.1%) showed antibody evidence of H5N1 exposure when compared to migratory or resident birds. The greatest number of seropositive birds in each category were Muschovy duck (captive), striated heron (resident), and the Pacific golden plover (migratory). Seven apparently well captive birds yielded molecular evidence of H5N1 infection. Following amplification, the HA, NA, and M genes were analyzed. Phylogenetic analysis of the HA gene showed that the isolates were 97% similar to EU124153.1 A/chicken/West Java/Garut May 2006, an isolate obtained in a similar region of West Java. While no known markers of neuraminidase inhibitor resistance were found within the NA gene, M segment analysis revealed the V27A mutation known to confer resistance to adamantanes. Our results demonstrate moderate serologic evidence of H5N1 infection in captive birds, sampled in five sites in Java, Indonesia, but only occasional infection in resident and migratory birds. These data imply that in an enzoonotic region of Indonesia the role of migratory birds in transmission of H5N1 is limited.

  11. Influenza viruses and the evolution of avian influenza virus H5N1.

    Science.gov (United States)

    Skeik, Nedaa; Jabr, Fadi I

    2008-05-01

    Although small in size and simple in structure, influenza viruses are sophisticated organisms with highly mutagenic genomes and wide antigenic diversity. They are species-specific organisms. Mutation and reassortment have resulted in newer viruses such as H5N1, with new resistance against anti-viral medications, and this might lead to the emergence of a fully transmissible strain, as occurred in the 1957 and 1968 pandemics. Influenza viruses are no longer just a cause of self-limited upper respiratory tract infections; the H5N1 avian influenza virus can cause severe human infection with a mortality rate exceeding 50%. The case death rate of H5N1 avian influenza infection is 20 times higher than that of the 1918 infection (50% versus 2.5%), which killed 675000 people in the USA and almost 40 million people worldwide. While the clock is still ticking towards what seems to be inevitable pandemic influenza, on April 17, 2007 the U.S. Food and Drug Administration (FDA) approved the first vaccine against the avian influenza virus H5N1 for humans at high risk. However, more research is needed to develop a more effective and affordable vaccine that can be given at lower doses.

  12. Highly Pathogenic Avian Influenza H5N1 in Mainland China

    Directory of Open Access Journals (Sweden)

    Xin-Lou Li

    2015-05-01

    Full Text Available Highly pathogenic avian influenza (HPAI H5N1 has posed a significant threat to both humans and birds, and it has spanned large geographic areas and various ecological systems throughout Asia, Europe and Africa, but especially in mainland China. Great efforts in control and prevention of the disease, including universal vaccination campaigns in poultry and active serological and virological surveillance, have been undertaken in mainland China since the beginning of 2006. In this study, we aim to characterize the spatial and temporal patterns of HPAI H5N1, and identify influencing factors favoring the occurrence of HPAI H5N1 outbreaks in poultry in mainland China. Our study shows that HPAI H5N1 outbreaks took place sporadically after vaccination campaigns in poultry, and mostly occurred in the cold season. The positive tests in routine virological surveillance of HPAI H5N1 virus in chicken, duck, goose as well as environmental samples were mapped to display the potential risk distribution of the virus. Southern China had a higher positive rate than northern China, and positive samples were mostly detected from chickens in the north, while the majority were from duck in the south, and a negative correlation with monthly vaccination rates in domestic poultry was found (R = −0.19, p value = 0.005. Multivariate panel logistic regression identified vaccination rate, interaction between distance to the nearest city and national highway, interaction between distance to the nearest lake and wetland, and density of human population, as well as the autoregressive term in space and time as independent risk factors in the occurrence of HPAI H5N1 outbreaks, based on which a predicted risk map of the disease was derived. Our findings could provide new understanding of the distribution and transmission of HPAI H5N1 in mainland China and could be used to inform targeted surveillance and control efforts in both human and poultry populations to reduce the risk of

  13. Sequence and epitope analysis of surface proteins of avian influenza H5N1 viruses from Asian patients

    Institute of Scientific and Technical Information of China (English)

    LI Guanglin; TAO Shiheng; WANG Xiujie

    2006-01-01

    Increasing cases of human infections with the high pathogenic avian influenza virus H5N1 have raised great concern on potential human flu pandemics caused by H5N1. The two viral surface glycoproteins, the hemagglutinin (HA) and the neuraminidase (NA) proteins, are major antigens of H5N1. Introducing new mutations on these two proteins is the major strategy used by H5N1 to expand host range and to avoid the recognition of host immune systems. We analyzed the two surface proteins of H5N1 from Asian human patients and identified many new mutation sites, including a few that were unique to certain lethal strains. We also analyzed the distribution of mutations on different epitopes of the two surface proteins. A receptor-binding site that might involve in the determination of host specificity of H5N1 was also found. Results reported here provided information for better understanding of the evolution trend of H5N1 genome in human.

  14. Bird migration and risk for H5N1 transmission into Qinghai Lake, China.

    Science.gov (United States)

    Cui, Peng; Hou, Yuansheng; Xing, Zhi; He, Yubang; Li, Tianxian; Guo, Shan; Luo, Ze; Yan, Baoping; Yin, Zuohua; Lei, Fumin

    2011-05-01

    The highly pathogenic avian influenza H5N1 virus still cause devastating effects to humans, agricultural poultry flocks, and wild birds. Wild birds are also detected to carry H5N1 over long distances and are able to introduce it into new areas during migration. In this article, our objective is to provide lists of bird species potentially involved in the introduction of highly pathogenic avian influenza H5N1 in Qinghai Lake, which is an important breeding and stopover site for aquatic birds along the Central Asian Flyway. Bird species were classified according to the following behavioral and ecological factors: migratory status, abundance, degree of mixing species and gregariousness, and the prevalence rate of H5N1 virus. Most of the high-risk species were from the family Anatidae, order Anseriformes (9/14 in spring, 11/15 in fall). We also estimated the relative risk of bird species involved by using a semi-quantitative method; species from family Anatidae accounted for over 39% and over 91% of the total risk at spring and fall migration periods, respectively. Results also show the relative risk for each bird aggregating site in helping to identify high-risk areas. This work may also be instructive and meaningful to the avian influenza surveillance in the breeding, stopover, and wintering sites besides Qinghai Lake along the Central Asian Flyway.

  15. Hemagglutinin from the H5N1 virus activates Janus kinase 3 to dysregulate innate immunity.

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    Wei Xu

    Full Text Available Highly pathogenic avian influenza viruses (HPAIVs cause severe disease in humans. There are no effective vaccines or antiviral therapies currently available to control fatal outbreaks due in part to the lack of understanding of virus-mediated immunopathology. In our study, we used hemagglutinin (HA of H5N1 virus to investigate the related signaling pathways and their relationship to dysregulated innate immune reaction. We found the HA of H5N1 avian influenza triggered an abnormal innate immune signalling in the pulmonary epithelial cells, through an unusual process involving activation of Janus kinase 3 (JAK3 that is exclusively associated with γc chain and is essential for signaling via all γc cytokine receptors. By using a selective JAK3 inhibitor and JAK3 knockout mice, we have, for the first time, demonstrated the ability to target active JAK3 to counteract injury to the lungs and protect immunocytes from acute hypercytokinemia -induced destruction following the challenge of H5N1 HA in vitro and in vivo. On the basis of the present data, it appears that the efficacy of selective JAK3 inhibition is likely based on its ability to block multiple cytokines and protect against a superinflammatory response to pathogen-associated molecular patterns (PAMPs attack. Our findings highlight the potential value of selective JAK3 inhibitor in treating the fatal immunopathology caused by H5N1 challenge.

  16. Seroprevalence of avian influenza A (H5N1 virus among poultry workers in Jiangsu Province, China: an observational study

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    Huo Xiang

    2012-04-01

    Full Text Available Abstract Background Since 2003 to 06 Jan 2012, the number of laboratory confirmed human cases of infection with avian influenza in China was 41 and 27 were fatal. However, the official estimate of the H5N1 case-fatality rate has been described by some as an over estimation since there may be numerous undetected asymptomatic/mild cases of H5N1 infection. This study was conducted to better understand the real infection rate and evaluate the potential risk factors for the zoonotic spread of H5N1 viruses to humans. Methods A seroepidemiological survey was conducted in poultry workers, a group expected to have the highest level of exposure to H5N1-infected birds, from 3 counties with habitat lakes of wildfowl in Jiangsu province, China. Serum specimens were collected from 306 participants for H5N1 serological test. All participants were interviewed to collect information about poultry exposures. Results The overall seropositive rate was 2.61% for H5N1 antibodies. The poultry number was found associated with a 2.39-fold significantly increased subclinical infection risk after adjusted with age and gender. Conclusions Avian-to -human transmission of avian H5N1 virus remained low. Workers associated with raising larger poultry flocks have a higher risk on seroconversion.

  17. Influenza A virus H5N1 entry into host cells is through clathrin-dependent endocytosis

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Influenza A virus H5N1 presents a major threat to human health. The entry of influenza virus into host cells is believed to be mediated by hemagglutinin (HA), a virus surface glycoprotein that can bind terminal sialic acid residues on host cell glycoproteins and glycolipids. In this study, we elucidated the pathways through which H5N1 enters human lung carcinoma cell line A549. We first proved that H5N1 can enter A549 cells via endocytosis, as lysosomotropic agents, such as bafilomycin A1 and chloroquine, can rescue H5N1-induced A549 cell death. By using specific inhibitors, and siRNAs that target the clathrin pathway, we further found that H5N1 could enter A549 cells via clathrin-mediated endocytosis, while inhibitors targeting caveolae-mediated endocytosis could not inhibit H5N1 cell entry. These findings expand our understanding of H5N1 pathogenesis and provide new information for anti-viral drug research.

  18. Epitope mapping of neutralizing monoclonal antibody in avian influenza A H5N1 virus hemagglutinin.

    Science.gov (United States)

    Ohkura, Takashi; Kikuchi, Yuji; Kono, Naoko; Itamura, Shigeyuki; Komase, Katsuhiro; Momose, Fumitaka; Morikawa, Yuko

    2012-02-03

    The global spread of highly pathogenic avian influenza A H5N1 viruses raises concerns about more widespread infection in the human population. Pre-pandemic vaccine for H5N1 clade 1 influenza viruses has been produced from the A/Viet Nam/1194/2004 strain (VN1194), but recent prevalent avian H5N1 viruses have been categorized into the clade 2 strains, which are antigenically distinct from the pre-pandemic vaccine. To understand the antigenicity of H5N1 hemagglutinin (HA), we produced a neutralizing monoclonal antibody (mAb12-1G6) using the pre-pandemic vaccine. Analysis with chimeric and point mutant HAs revealed that mAb12-1G6 bound to the loop (amino acid positions 140-145) corresponding to an antigenic site A in the H3 HA. mAb12-1G6 failed to bind to the mutant VN1194 HA when only 3 residues were substituted with the corresponding residues of the clade 2.1.3.2 A/Indonesia/5/05 strain (amino acid substitutions at positions Q142L, K144S, and S145P), suggesting that these amino acids are critical for binding of mAb12-1G6. Escape mutants of VN1194 selected with mAb12-1G6 carried a S145P mutation. Interestingly, mAb12-1G6 cross-neutralized clade 1 and clade 2.2.1 but not clade 2.1.3.2 or clade 2.3.4 of the H5N1 virus. We discuss the cross-reactivity, based on the amino acid sequence of the epitope.

  19. Immunostimulatory motifs enhance antiviral siRNAs targeting highly pathogenic avian influenza H5N1.

    Directory of Open Access Journals (Sweden)

    Cameron R Stewart

    Full Text Available Highly pathogenic avian influenza (HPAI H5N1 virus is endemic in many regions around the world and remains a significant pandemic threat. To date H5N1 has claimed almost 300 human lives worldwide, with a mortality rate of 60% and has caused the death or culling of hundreds of millions of poultry since its initial outbreak in 1997. We have designed multi-functional RNA interference (RNAi-based therapeutics targeting H5N1 that degrade viral mRNA via the RNAi pathway while at the same time augmenting the host antiviral response by inducing host type I interferon (IFN production. Moreover, we have identified two factors critical for maximising the immunostimulatory properties of short interfering (siRNAs in chicken cells (i mode of synthesis and (ii nucleoside sequence to augment the response to virus. The 5-bp nucleoside sequence 5'-UGUGU-3' is a key determinant in inducing high levels of expression of IFN-α, -β, -λ and interleukin 1-β in chicken cells. Positioning of this 5'-UGUGU-3' motif at the 5'-end of the sense strand of siRNAs, but not the 3'-end, resulted in a rapid and enhanced induction of type I IFN. An anti-H5N1 avian influenza siRNA directed against the PB1 gene (PB1-2257 tagged with 5'-UGUGU-3' induced type I IFN earlier and to a greater extent compared to a non-tagged PB1-2257. Tested against H5N1 in vitro, the tagged PB1-2257 was more effective than non-tagged PB1-2257. These data demonstrate the ability of an immunostimulatory motif to improve the performance of an RNAi-based antiviral, a finding that may influence the design of future RNAi-based anti-influenza therapeutics.

  20. Biosafety Considerations of Mammalian-Transmissible H5N1 Influenza

    OpenAIRE

    2012-01-01

    Abstract The ability to produce an H5N1 influenza virus that can be transmitted from human to human raises both biosecurity and biosafety concerns. After analyzing the biosafety risks of such a virus, we propose that it be handled at biosafety level 4 (BSL4) containment until and unless it becomes clear that the risks to humans and other mammals can be mitigated.

  1. Avian influenza H5N1: an update on molecular pathogenesis

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Avian influenza A virus constitutes a large threat to human health. Recent outbreaks of highly pathogenic avian influenza H5N1 virus in poultry and in humans have raised concerns that an influenza pandemic will occur in the near future. Transmission from avian species to humans remains sporadic, but the mortality associated with human infection is very high (about 62%). To date, there are no effective therapeutic drugs or a prophylactic vaccines available, which means that there is still a long way to go before we can eradicate or cure avian influenza. This review focuses on the molecular pathogenesis of avian influenza H5N1 virus infection. An understanding of the viral pathogenesis may facilitate the development of novel treatments or effective eradication of this fatal disease.

  2. Avian influenza H5N1: an update on molecular pathogenesis

    Institute of Scientific and Technical Information of China (English)

    WANG HongLiang; JIANG ChengYu

    2009-01-01

    Avian influenza A virus constitutes a large threat to human health. Recent outbreaks of highly patho-genic avian influenza H5N1 virus in poultry and in humans have raised concerns that an influenza pandemic will occur in the near future. Transmission from avian species to humans remains sporadic, but the mortality associated with human infection is very high (about 62%). To date, there are no effec-tive therapeutic drugs or a prophylactic vaccines available, which means that there is still a long way to go before we can eradicate or cure avian influenza. This review focuses on the molecular pathogenesis of avian influenza H5N1 virus infection. An understanding of the viral pathogenesis may facilitate the development of novel treatments or effective eradication of this fatal disease.

  3. Avian influenza (H5N1 virus of clade 2.3.2 in domestic poultry in India.

    Directory of Open Access Journals (Sweden)

    Shanmuga Nagarajan

    Full Text Available South Asia has experienced regular outbreaks of H5N1 avian influenza virus since its first detection in India and Pakistan in February, 2006. Till 2009, the outbreaks in this region were due to clade 2.2 H5N1 virus. In 2010, Nepal reported the first outbreak of clade 2.3.2 virus in South Asia. In February 2011, two outbreaks of H5N1 virus were reported in the State of Tripura in India. The antigenic and genetic analyses of seven H5N1 viruses isolated during these outbreaks were carried out. Antigenic analysis confirmed 64 to 256-fold reduction in cross reactivity compared with clade 2.2 viruses. The intravenous pathogenicity index of the isolates ranged from 2.80-2.95 indicating high pathogenicity to chickens. Sequencing of all the eight gene-segments of seven H5N1 viruses isolated in these outbreaks was carried out. The predicted amino acid sequence analysis revealed high pathogenicity to chickens and susceptibility to the antivirals, amantadine and oseltamivir. Phylogenetic analyses indicated that these viruses belong to clade 2.3.2.1 and were distinct to the clade 2.3.2.1 viruses isolated in Nepal. Identification of new clade 2.3.2 H5N1 viruses in South Asia is reminiscent of the introduction of clade 2.2 viruses in this region in 2006/7. It is now important to monitor whether the clade 2.3.2.1 is replacing clade 2.2 in this region or co-circulating with it. Continued co-circulation of various subclades of the H5N1 virus which are more adapted to land based poultry in a highly populated region such as South Asia increases the risk of evolution of pandemic H5N1 strains.

  4. Synergistic Effect of S224P and N383D Substitutions in the PA of H5N1 Avian Influenza Virus Contributes to Mammalian Adaptation.

    Science.gov (United States)

    Song, Jiasheng; Xu, Jing; Shi, Jianzhong; Li, Yanbing; Chen, Hualan

    2015-05-22

    The adaptation of H5N1 avian influenza viruses to human poses a great threat to public health. Previous studies indicate the adaptive mutations in viral polymerase of avian influenza viruses are major contributors in overcoming the host species barrier, with the majority of mammalian adaptive mutations occurring in the PB2 protein. However, the adaptive mutations in the PA protein of the H5N1 avian influenza virus are less defined and poorly understood. In this study, we identified the synergistic effect of the PA/224P + 383D of H5N1 avian influenza viruses and its ability to enhance the pathogenicity and viral replication in a mammalian mouse model. Interestingly, the signature of PA/224P + 383D mainly exists in mammalian isolates of the H5N1 influenza virus and pdmH1N1 influenza virus, providing a potential pathway for the natural adaptation to mammals which imply the effects of natural adaptation to mammals. Notably, the mutation of PA/383D, which is highly conserved in avian influenza viruses, increases the polymerase activity in both avian and human cells, and may have roles in maintaining the avian influenza virus in their avian reservoirs, and jumping species to infect humans.

  5. Differences between influenza virus receptors on target cells of duck and chicken and receptor specificity of the 1997 H5N1 chicken and human influenza viruses from Hong Kong.

    Science.gov (United States)

    Gambaryan, A S; Tuzikov, A B; Bovin, N V; Yamnikova, S S; Lvov, D K; Webster, R G; Matrosovich, M N

    2003-01-01

    To study whether influenza virus receptors in chickens differ from those in other species, we compared the binding of lectins and influenza viruses with known receptor specificity to cell membranes and gangliosides from epithelial tissues of ducks, chickens, and African green monkeys. We found that chicken cells contained Neu5Ac alpha(2-6)Gal-terminated receptors recognized by Sambucus nigra lectin and by human viruses. This finding explains how some recent H9N2 viruses replicate in chickens despite their human virus-like receptor specificity. Duck virus bound to gangliosides with short sugar chains that were abundant in duck intestine. Human and chicken viruses did not bind to these gangliosides and bound more strongly than duck virus to gangliosides with long sugar chains that were found in chicken intestinal and monkey lung tissues. Chicken and duck viruses also differed by their ability to recognize the structure of the third sugar moiety in Sia2-3Gal-terminated receptors. Chicken viruses preferentially bound to Neu5Ac alpha(2-3)Gal beta(1-4)GlcNAc-containing synthetic sialylglycopolymer, whereas duck viruses displayed a higher affinity for Neu5Ac alpha(2-3)Gal beta(1-3)GalNAc-containing polymer. Our data indicate that sialyloligosaccharide receptors in different avian species are not identical and provide a potential explanation for the differences between the hemagglutinin and neuraminidase proteins of duck and chicken viruses.

  6. Molecular epidemiology of influenza A (H5N1) viruses, Bangladesh, 2007-2011.

    Science.gov (United States)

    Hoque, Md Ahasanul; Tun, Hein Min; Hassan, Mohammad Mahmudul; Khan, Shahneaz Ali; Islam, Skm Azizul; Islam, Md Nurul; Giasuddin, Md; Osmani, Tabm Muzaffar Goni; Islam, Ariful; Thornton, Ronald Norman; Burgess, Graham William; Skerratt, Lee Francis; Selleck, Paul; Brun, Edgar; Debnath, Nitish Chandra; Leung, Frederick Chi-Ching

    2013-09-01

    To investigate the origins, evolution and patterns of spread of HPAI H5N1 outbreaks in Bangladesh, we performed a phylogenetic reconstruction analysis using Bayesian methods. The analysis was conducted using 81 hemagglutinin (HA) gene sequences from the H5N1 viruses isolated in Bangladesh from 2007 to 2011, together with 264 publicly available HA sequences of clade 2.2, 2.3.2 and 2.3.4 retrieved from GenBank. Our study provides evidence that clade 2.2.2 viruses that caused outbreaks in Bangladesh were lineages independent from the viruses introduced earlier into India. Furthermore, the Bangladesh clade 2.2.2 descendents subsequently spread to India and Bhutan. This has implications for avian influenza control in southern Asia suggesting multiple routes of entry of the virus including one pathway that spread to neighboring countries via Bangladesh.

  7. Predicted epitopes of H5N1 bird flu virus by bioinformatics method: a clue for further vaccine development

    Institute of Scientific and Technical Information of China (English)

    Viroj Wiwnanitkit

    2006-01-01

    @@ To the Editor: Bird flu or avian flu, caused by H5N1 virus, is a new emerging infectious disease. It is noted that this H5N1 virus jumped the species barrier and caused severe disease with high mortality in humans in many countries. The continued westward dissemination of H5N1 influenza A viruses in avian populations and the nearly 50% mortality of humans infected with H5N1 are a source of great international concern.1Providing sufficient antiviral drugs and development and approval of new vaccines are the keys for control of the possible emerging pandemic of this atypical influenza.1,2 Based on the advance in bioinformatics, the immunomics becomes a new alternative in vaccine development.3

  8. Metapopulation dynamics enable persistence of influenza A, including A/H5N1, in poultry.

    Science.gov (United States)

    Hosseini, Parviez Rana; Fuller, Trevon; Harrigan, Ryan; Zhao, Delong; Arriola, Carmen Sofia; Gonzalez, Armandoe; Miller, Matthew Joshua; Xiao, Xiangming; Smith, Tom B; Jones, Jamie Holland; Daszak, Peter

    2013-01-01

    Highly pathogenic influenza A/H5N1 has persistently but sporadically caused human illness and death since 1997. Yet it is still unclear how this pathogen is able to persist globally. While wild birds seem to be a genetic reservoir for influenza A, they do not seem to be the main source of human illness. Here, we highlight the role that domestic poultry may play in maintaining A/H5N1 globally, using theoretical models of spatial population structure in poultry populations. We find that a metapopulation of moderately sized poultry flocks can sustain the pathogen in a finite poultry population for over two years. Our results suggest that it is possible that moderately intensive backyard farms could sustain the pathogen indefinitely in real systems. This fits a pattern that has been observed from many empirical systems. Rather than just employing standard culling procedures to control the disease, our model suggests ways that poultry production systems may be modified.

  9. Lethal infection by a novel reassortant H5N1 avian influenza A virus in a zoo-housed tiger.

    Science.gov (United States)

    He, Shang; Shi, Jianzhong; Qi, Xian; Huang, Guoqing; Chen, Hualan; Lu, Chengping

    2015-01-01

    In early 2013, a Bengal tiger (Panthera tigris) in a zoo died of respiratory distress. All specimens from the tiger were positive for HPAI H5N1, which were detected by real-time PCR, including nose swab, throat swab, tracheal swab, heart, liver, spleen, lung, kidney, aquae pericardii and cerebrospinal fluid. One stain of virus, A/Tiger/JS/1/2013, was isolated from the lung sample. Pathogenicity experiments showed that the isolate was able to replicate and cause death in mice. Phylogenetic analysis indicated that HA and NA of A/Tiger/JS/1/2013 clustered with A/duck/Vietnam/OIE-2202/2012 (H5N1), which belongs to clade 2.3.2.1. Interestingly, the gene segment PB2 shared 98% homology with A/wild duck/Korea/CSM-28/20/2010 (H4N6), which suggested that A/Tiger/JS/1/2013 is a novel reassortant H5N1 subtype virus. Immunohistochemical analysis also confirmed that the tiger was infected by this new reassortant HPAI H5N1 virus. Overall, our results showed that this Bengal tiger was infected by a novel reassortant H5N1, suggesting that the H5N1 virus can successfully cross species barriers from avian to mammal through reassortment.

  10. Pathogenicity of Highly Pathogenic Avian Influenza Virus H5N1 in Naturally Infected Poultry in Egypt.

    Directory of Open Access Journals (Sweden)

    Ibrahim Thabet Hagag

    Full Text Available Highly pathogenic avian influenza virus (HPAIV H5N1 has been endemic in Egypt since 2006, and there is increasing concern for its potential to become highly transmissible among humans. Infection by HPAIV H5N1 has been described in experimentally challenged birds. However, the pathogenicity of the H5N1 isolated in Egypt has never been reported in naturally infected chickens and ducks. Here we report a 2013 outbreak of HPAIV H5N1 in commercial poultry farms and backyards in Sharkia Province, Egypt. The main symptoms were ecchymosis on the shanks and feet, cyanosis of the comb and wattles, subcutaneous edema of the head and neck for chickens, and nervous signs (torticollis for ducks. Within 48-72 hrs of the onset of illness, the average mortality rates were 22.8-30% and 28.5-40% in vaccinated chickens and non-vaccinated ducks, respectively. Tissue samples of chickens and ducks were collected for analyses with cross-section immunohistochemistry and real-time RT-PCR for specific viral RNA transcripts. While viral RNA was detected in nearly all tissues and sera collected, viral nucleoprotein was detected almost ubiquitously in all tissues, including testis. Interestingly, viral antigen was also observed in endothelial cells of most organs in chickens, and clearly detected in the trachea and brain in particular. Viral nucleoprotein was also detected in mononuclear cells of various organs, especially pulmonary tissue. We performed phylogenetic analyses and compared the genomic sequences of the hemagglutinin (HA and nonstructural proteins (NS among the isolated viruses, the HPAIV circulated in Egypt in the past and currently, and some available vaccine strains. Further analysis of deduced amino acids of both HA and NS1 revealed that our isolates carried molecular determinants of HPAIV, including the multibasic amino acids (PQGERRRK/KR*GLF in the cleavage site in HA and glutamate at position 92 (D92E in NS1. This is the first report of the pathogenicity

  11. Highly pathogenic avian influenza H5N1 virus could partly be evacuated by pregnant BALB/c mouse during abortion or preterm delivery.

    Science.gov (United States)

    Xu, Lili; Bao, Linlin; Deng, Wei; Qin, Chuan

    2011-07-08

    The highly pathogenic avian influenza H5N1 virus is one of candidates for future pandemic. Since H5N1 viruses had previously been isolated only from avian species, the outbreak raised questions about the ability of these viruses to cause severe disease and death in humans. Pregnant women are at increased risk for influenza-associated illness and death. However, little is known about whether influenza viruses could transmit to the fetus through the placenta, and the effects of abortion and preterm delivery to maternal influenza infection are not well understood. We found that the H5N1 viruses could vertical transmit to the fetus through the placenta in the BALB/c mouse model, and the viruses could partly be evacuated by the pregnant mice during abortion or preterm delivery. This study may further our understanding about the transmission of this highly pathogenic avian influenza viruses, supply optimized clinical treatment method for pregnant women, and shed some light on better preventing and controlling for future potential outbreak of H5N1 influenza pandemic.

  12. Highly pathogenic avian influenza H5N1 virus could partly be evacuated by pregnant BALB/c mouse during abortion or preterm delivery

    Directory of Open Access Journals (Sweden)

    Deng Wei

    2011-07-01

    Full Text Available Abstract The highly pathogenic avian influenza H5N1 virus is one of candidates for future pandemic. Since H5N1 viruses had previously been isolated only from avian species, the outbreak raised questions about the ability of these viruses to cause severe disease and death in humans. Pregnant women are at increased risk for influenza-associated illness and death. However, little is known about whether influenza viruses could transmit to the fetus through the placenta, and the effects of abortion and preterm delivery to maternal influenza infection are not well understood. We found that the H5N1 viruses could vertical transmit to the fetus through the placenta in the BALB/c mouse model, and the viruses could partly be evacuated by the pregnant mice during abortion or preterm delivery. This study may further our understanding about the transmission of this highly pathogenic avian influenza viruses, supply optimized clinical treatment method for pregnant women, and shed some light on better preventing and controlling for future potential outbreak of H5N1 influenza pandemic.

  13. Live bird markets of Bangladesh: H9N2 viruses and the near absence of highly pathogenic H5N1 influenza.

    Directory of Open Access Journals (Sweden)

    Nicholas J Negovetich

    Full Text Available Avian influenza surveillance in Bangladesh has been passive, relying on poultry farmers to report suspected outbreaks of highly pathogenic H5N1 influenza. Here, the results of an active surveillance effort focusing on the live-bird markets are presented. Prevalence of influenza infection in the birds of the live bird markets is 23.0%, which is similar to that in poultry markets in other countries. Nearly all of the isolates (94% were of the non-pathogenic H9N2 subtype, but viruses of the H1N2, H1N3, H3N6, H4N2, H5N1, and H10N7 subtypes were also observed. The highly pathogenic H5N1-subtype virus was observed at extremely low prevalence in the surveillance samples (0.08%, and we suggest that the current risk of infection for humans in the retail poultry markets in Bangladesh is negligible. However, the high prevalence of the H9 subtype and its potential for interaction with the highly pathogenic H5N1-subtype, i.e., reassortment and attenuation of host morbidity, highlight the importance of active surveillance of the poultry markets.

  14. Modelling H5N1 in Bangladesh across spatial scales: Model complexity and zoonotic transmission risk.

    Science.gov (United States)

    Hill, Edward M; House, Thomas; Dhingra, Madhur S; Kalpravidh, Wantanee; Morzaria, Subhash; Osmani, Muzaffar G; Yamage, Mat; Xiao, Xiangming; Gilbert, Marius; Tildesley, Michael J

    2017-09-01

    Highly pathogenic avian influenza H5N1 remains a persistent public health threat, capable of causing infection in humans with a high mortality rate while simultaneously negatively impacting the livestock industry. A central question is to determine regions that are likely sources of newly emerging influenza strains with pandemic causing potential. A suitable candidate is Bangladesh, being one of the most densely populated countries in the world and having an intensifying farming system. It is therefore vital to establish the key factors, specific to Bangladesh, that enable both continued transmission within poultry and spillover across the human-animal interface. We apply a modelling framework to H5N1 epidemics in the Dhaka region of Bangladesh, occurring from 2007 onwards, that resulted in large outbreaks in the poultry sector and a limited number of confirmed human cases. This model consisted of separate poultry transmission and zoonotic transmission components. Utilising poultry farm spatial and population information a set of competing nested models of varying complexity were fitted to the observed case data, with parameter inference carried out using Bayesian methodology and goodness-of-fit verified by stochastic simulations. For the poultry transmission component, successfully identifying a model of minimal complexity, which enabled the accurate prediction of the size and spatial distribution of cases in H5N1 outbreaks, was found to be dependent on the administration level being analysed. A consistent outcome of non-optimal reporting of infected premises materialised in each poultry epidemic of interest, though across the outbreaks analysed there were substantial differences in the estimated transmission parameters. The zoonotic transmission component found the main contributor to spillover transmission of H5N1 in Bangladesh was found to differ from one poultry epidemic to another. We conclude by discussing possible explanations for these discrepancies in

  15. Predominance and geo-mapping of avian influenza H5N1 in poultry sectors in Egypt

    Directory of Open Access Journals (Sweden)

    Abdelsatar Arafa

    2016-11-01

    Full Text Available Highly pathogenic avian influenza (HPAI virus of the H5N1 subtype has been enzootic in the Egyptian poultry with significant human infections since 2008. This work evaluates the epidemiological and virological information from February 2006 to May 2015 in spatial and temporal terms. Only data with confirmed HPAI H5N1 sub-type were collected, and matched with the epidemiological data from various spatially and temporally-dispersed surveillances implemented between 2006 and 2015. Spatio-temporal analysis was conducted on a total of 3338 confirmed H5N1 HPAI poultry disease outbreaks and outputs described based on transmission patterns, poultry species, production types affected, trade, geographic and temporal distributions in Egypt. The H5N1 virus persists in the Egyptian poultry displaying a seasonal pattern with peak prevalence between January and March. There was no specific geographic pattern, but chickens and ducks were more affected. However, relatively higher disease incidences were recorded in the Nile Delta. Phylogenetic studies of the haemagglutinin gene sequences of H5N1 viruses indicated that multiple clusters circulated between 2006 and 2015, with significant deviations in circulation. Epidemiological dynamics of HPAI has changed with the origins of majority of outbreaks shifted to household poultry. The persistence of HPAI H5N1 in poultry with recurrent and sporadic infections in humans can influence virus evolution spatio-temporally. Household poultry plays significant roles in the H5N1 virus transmission to poultry and humans, but the role of commercial poultry needs further clarifications. While poultry trading supports the persistence and transmission of H5N1, the role of individual species may warrant further investigation. Surveillance activities, applying a multi-sectoral approach, are recommended.

  16. Interspecies transmission and host restriction of avian H5N1 influenza virus

    Institute of Scientific and Technical Information of China (English)

    LIU Di; LIU XiaoLing; YAN JingHua; LIU Wen-Jun; GAO George Fu

    2009-01-01

    Long-term endemicity of avian H5N1 influenza virus in poultry and continuous sporadic human infec-tions in several countries has raised the concern of another potential pandemic influenza. Suspicion of the avian origin of the previous pandemics results in the close investigation of the mechanism of in-terspecies transmission. Entry and fusion is the first step for the H5N1 influenza virus to get into the host cells affecting the host ranges. Therefore receptor usage study has been a major focus for the last few years. We now know the difference of the sialic acid structures and distributions in different spe-cies, even in the different parts of the same host. Many host factors interacting with the influenza virus component proteins have been identified and their role in the host range expansion and interspecies transmission is under detailed scrutiny. Here we review current progress in the receptor usage and host factors.

  17. Interspecies transmission and host restriction of avian H5N1 influenza virus

    Institute of Scientific and Technical Information of China (English)

    GAO; George; Fu

    2009-01-01

    Long-term endemicity of avian H5N1 influenza virus in poultry and continuous sporadic human infections in several countries has raised the concern of another potential pandemic influenza. Suspicion of the avian origin of the previous pandemics results in the close investigation of the mechanism of interspecies transmission. Entry and fusion is the first step for the H5N1 influenza virus to get into the host cells affecting the host ranges. Therefore receptor usage study has been a major focus for the last few years. We now know the difference of the sialic acid structures and distributions in different species, even in the different parts of the same host. Many host factors interacting with the influenza virus component proteins have been identified and their role in the host range expansion and interspecies transmission is under detailed scrutiny. Here we review current progress in the receptor usage and host factors.

  18. Avian Influenza (H5N1) Expert System using Dempster-Shafer Theory

    CERN Document Server

    Maseleno, Andino

    2012-01-01

    Based on Cumulative Number of Confirmed Human Cases of Avian Influenza (H5N1) Reported to World Health Organization (WHO) in the 2011 from 15 countries, Indonesia has the largest number death because Avian Influenza which 146 deaths. In this research, the researcher built an Avian Influenza (H5N1) Expert System for identifying avian influenza disease and displaying the result of identification process. In this paper, we describe five symptoms as major symptoms which include depression, combs, wattle, bluish face region, swollen face region, narrowness of eyes, and balance disorders. We use chicken as research object. Research location is in the Lampung Province, South Sumatera. The researcher reason to choose Lampung Province in South Sumatera on the basis that has a high poultry population. Dempster-Shafer theory to quantify the degree of belief as inference engine in expert system, our approach uses Dempster-Shafer theory to combine beliefs under conditions of uncertainty and ignorance, and allows quantitat...

  19. Avian influenza virus (H5N1; effects of physico-chemical factors on its survival

    Directory of Open Access Journals (Sweden)

    Hameed Sajid

    2009-03-01

    Full Text Available Abstract Present study was performed to determine the effects of physical and chemical agents on infective potential of highly pathogenic avian influenza (HPAI H5N1 (local strain virus recently isolated in Pakistan during 2006 outbreak. H5N1 virus having titer 108.3 ELD50/ml was mixed with sterilized peptone water to get final dilution of 4HA units and then exposed to physical (temperature, pH and ultraviolet light and chemical (formalin, phenol crystals, iodine crystals, CID 20, virkon®-S, zeptin 10%, KEPCIDE 300, KEPCIDE 400, lifebuoy, surf excel and caustic soda agents. Harvested amnio-allantoic fluid (AAF from embryonated chicken eggs inoculated with H5N1 treated virus (0.2 ml/egg was subjected to haemagglutination (HA and haemagglutination inhibition (HI tests. H5N1 virus lost infectivity after 30 min at 56°C, after 1 day at 28°C but remained viable for more than 100 days at 4°C. Acidic pH (1, 3 and basic pH (11, 13 were virucidal after 6 h contact time; however virus retained infectivity at pH 5 (18 h, 7 and 9 (more than 24 h. UV light was proved ineffectual in inactivating virus completely even after 60 min. Soap (lifebuoy®, detergent (surf excel® and alkali (caustic soda destroyed infectivity after 5 min at 0.1, 0.2 and 0.3% dilution. All commercially available disinfectants inactivated virus at recommended concentrations. Results of present study would be helpful in implementing bio-security measures at farms/hatcheries levels in the wake of avian influenza virus (AIV outbreak.

  20. Protection against H5N1 highly pathogenic avian and pandemic (H1N1) 2009 influenza virus infection in cynomolgus monkeys by an inactivated H5N1 whole particle vaccine.

    Science.gov (United States)

    Nakayama, Misako; Shichinohe, Shintaro; Itoh, Yasushi; Ishigaki, Hirohito; Kitano, Mitsutaka; Arikata, Masahiko; Pham, Van Loi; Ishida, Hideaki; Kitagawa, Naoko; Okamatsu, Masatoshi; Sakoda, Yoshihiro; Ichikawa, Takaya; Tsuchiya, Hideaki; Nakamura, Shinichiro; Le, Quynh Mai; Ito, Mutsumi; Kawaoka, Yoshihiro; Kida, Hiroshi; Ogasawara, Kazumasa

    2013-01-01

    H5N1 highly pathogenic avian influenza virus (HPAIV) infection has been reported in poultry and humans with expanding clade designations. Therefore, a vaccine that induces immunity against a broad spectrum of H5N1 viruses is preferable for pandemic preparedness. We established a second H5N1 vaccine candidate, A/duck/Hokkaido/Vac-3/2007 (Vac-3), in our virus library and examined the efficacy of inactivated whole particles of this strain against two clades of H5N1 HPAIV strains that caused severe morbidity in cynomolgus macaques. Virus propagation in vaccinated macaques infected with either of the H5N1 HPAIV strains was prevented compared with that in unvaccinated macaques. This vaccine also prevented propagation of a pandemic (H1N1) 2009 virus in macaques. In the vaccinated macaques, neutralization activity, which was mainly shown by anti-hemagglutinin antibody, against H5N1 HPAIVs in plasma was detected, but that against H1N1 virus was not detected. However, neuraminidase inhibition activity in plasma and T-lymphocyte responses in lymph nodes against H1N1 virus were detected. Therefore, cross-clade and heterosubtypic protective immunity in macaques consisted of humoral and cellular immunity induced by vaccination with Vac-3.

  1. Modelling H5N1 in Bangladesh across spatial scales: Model complexity and zoonotic transmission risk

    Directory of Open Access Journals (Sweden)

    Edward M. Hill

    2017-09-01

    Full Text Available Highly pathogenic avian influenza H5N1 remains a persistent public health threat, capable of causing infection in humans with a high mortality rate while simultaneously negatively impacting the livestock industry. A central question is to determine regions that are likely sources of newly emerging influenza strains with pandemic causing potential. A suitable candidate is Bangladesh, being one of the most densely populated countries in the world and having an intensifying farming system. It is therefore vital to establish the key factors, specific to Bangladesh, that enable both continued transmission within poultry and spillover across the human–animal interface. We apply a modelling framework to H5N1 epidemics in the Dhaka region of Bangladesh, occurring from 2007 onwards, that resulted in large outbreaks in the poultry sector and a limited number of confirmed human cases. This model consisted of separate poultry transmission and zoonotic transmission components. Utilising poultry farm spatial and population information a set of competing nested models of varying complexity were fitted to the observed case data, with parameter inference carried out using Bayesian methodology and goodness-of-fit verified by stochastic simulations. For the poultry transmission component, successfully identifying a model of minimal complexity, which enabled the accurate prediction of the size and spatial distribution of cases in H5N1 outbreaks, was found to be dependent on the administration level being analysed. A consistent outcome of non-optimal reporting of infected premises materialised in each poultry epidemic of interest, though across the outbreaks analysed there were substantial differences in the estimated transmission parameters. The zoonotic transmission component found the main contributor to spillover transmission of H5N1 in Bangladesh was found to differ from one poultry epidemic to another. We conclude by discussing possible explanations for

  2. Serosurveillance study on transmission of H5N1 virus during a 2006 avian influenza epidemic.

    Science.gov (United States)

    Ceyhan, M; Yildirim, I; Ferraris, O; Bouscambert-Duchamp, M; Frobert, E; Uyar, N; Tezer, H; Oner, A F; Buzgan, T; Torunoglu, M A; Ozkan, B; Yilmaz, R; Kurtoglu, M G; Laleli, Y; Badur, S; Lina, B

    2010-09-01

    In 2006 an outbreak of avian influenza A(H5N1) in Turkey caused 12 human infections, including four deaths. We conducted a serological survey to determine the extent of subclinical infection caused by the outbreak. Single serum samples were collected from five individuals with avian influenza whose nasopharyngeal swabs tested positive for H5 RNA by polymerase chain reaction, 28 family contacts of the cases, 95 poultry cullers, 75 individuals known to have had contact with diseased chickens and 81 individuals living in the region with no known contact with infected chickens and/or patients. Paired serum samples were collected from 97 healthcare workers. All sera were tested for the presence of neutralizing antibodies by enzyme-linked immunoassay, haemagglutination inhibition and microneutralization assays. Only one serum sample, from a parent of an avian influenza patient, tested positive for H5N1 by microneutralization assay. This survey shows that there was minimal subclinical H5N1 infection among contacts of human cases and infected poultry in Turkey in 2006. Further, the low rate of subclinical infection following contact with diseased poultry gave further support to the reported low infectivity of the virus.

  3. Influenza A virus H5N1 entry into host cells is through clathrin-dependent endocytosis

    Institute of Scientific and Technical Information of China (English)

    WANG HongLiang; JIANG ChengYu

    2009-01-01

    Influenza A virus H5N1 presents a major threat to human health. The entry of influenza virus into host cells is believed to be mediated by hemagglutinin (HA), a virus surface glycoprotein that can bind ter-minal sialic acid residues on host cell glycoproteins and glycolipids. In this study, we elucidated the pathways through which H5N1 enters human lung carcinoma cell line A549. We first proved that H5N1 can enter A549 cells via endocytosis, as lysosomotropic agents, such as bafilomycin A1 and chloro. quine, can rescue H5Nl-induced A549 cell death. By using specific inhibitors, and siRNAs that target the clathrin pathway, we further found that H5N1 could enter A549 cells via clathrin-mediated endocy-tosis, while inhibitors targeting caveolae-mediated endocytosis could not inhibit H5N1 cell entry. These findings expand our understanding of H5N1 pathogenesis and provide new information for anti-viral drug research.

  4. Ecologic risk factor investigation of clusters of avian influenza A (H5N1) virus infection in Thailand.

    Science.gov (United States)

    Tiensin, Thanawat; Ahmed, Syed Sayeem Uddin; Rojanasthien, Suvichai; Songserm, Thaweesak; Ratanakorn, Parntep; Chaichoun, Kridsada; Kalpravidh, Wantanee; Wongkasemjit, Surapong; Patchimasiri, Tuangthong; Chanachai, Karoon; Thanapongtham, Weerapong; Chotinan, Suwit; Stegeman, Arjan; Nielen, Mirjam

    2009-06-15

    This study was conducted to investigate space and time clusters of highly pathogenic avian influenza A (H5N1) virus infection and to determine risk factors at the subdistrict level in Thailand. Highly pathogenic avian influenza A (H5N1) was diagnosed in 1890 poultry flocks located in 953 subdistricts during 2004-2007. The ecologic risk for H5N1 virus infection was assessed on the basis of a spatial-based case-control study involving 824 case subdistricts and 3296 control subdistricts from 6 study periods. Risk factors investigated in clustered areas of H5N1 included human and animal demographic characteristics, poultry production systems, and wild birds and their habitats. Six variables remained statistically significant in the final model: flock density of backyard chickens (odds ratio [OR], 0.98), flock density of fighting cocks (OR, 1.02), low and high human density (OR, 0.60), presence of quail flocks (OR, 1.21), free-grazing duck flocks (OR, 2.17), and a poultry slaughterhouse (OR, 1.33). We observed a strong association between subdistricts with H5N1 virus-infected poultry flocks and evidence of prior and concomitant H5N1 infection in wild birds in the same subdistrict.

  5. Progress in Research on Pandemic Influenza H5N1 Vaccine%H5N1大流行流感疫苗的研究进展

    Institute of Scientific and Technical Information of China (English)

    张严予

    2011-01-01

    Highly pathogenic avian influenza H5N1 virus may cause serious fatal diseases and constitute a grave threat to human health. Although the current H5N1 influenza strains appear not to be transmissible from human to human, it is of major concern that mixing with human influenza strains could convert H5N1 to a strain that would spread that would spread from human to human and cause a serious pandemic. In addition, avian influenza H5N1 virus after continuous variation may break through the species barrier and spread to mammals and humans, thereby cause disease even death under the influence of various virus and host factors. This paper reviews the progress in research on pandemic influenza vaccine.%高致病性H5N1流感病毒可导致严重的致死性疾病,对人类健康造成了极大威胁.尽管目前尚未发生人与人之间传播,但该病毒一旦与人流感病毒重组,即有可能转变为可在人与人之间传播的高致死性流感病毒,从而导致新的流感大流行.此外,H5N1流感病毒经过不断变异后可突破种属屏障,从禽类传播给哺乳动物及人类,并进一步在病毒和宿主的多种因素作用下导致宿主发病乃至死亡.本文对H5N1大流行流感疫苗的研究进展作一综述.

  6. Highly Pathogenic Avian Influenza A(H5N1) Virus Struck Migratory Birds in China in 2015.

    Science.gov (United States)

    Bi, Yuhai; Zhang, Zhenjie; Liu, Wenjun; Yin, Yanbo; Hong, Jianmin; Li, Xiangdong; Wang, Haiming; Wong, Gary; Chen, Jianjun; Li, Yunfeng; Ru, Wendong; Gao, Ruyi; Liu, Di; Liu, Yingxia; Zhou, Boping; Gao, George F; Shi, Weifeng; Lei, Fumin

    2015-08-11

    Approximately 100 migratory birds, including whooper swans and pochards, were found dead in the Sanmenxia Reservoir Area of China during January 2015. The causative agent behind this outbreak was identified as H5N1 highly pathogenic avian influenza virus (HPAIV). Genetic and phylogenetic analyses revealed that this Sanmenxia H5N1 virus was a novel reassortant, possessing a Clade 2.3.2.1c HA gene and a H9N2-derived PB2 gene. Sanmenxia Clade 2.3.2.1c-like H5N1 viruses possess the closest genetic identity to A/Alberta/01/2014 (H5N1), which recently caused a fatal respiratory infection in Canada with signs of meningoencephalitis, a highly unusual symptom with influenza infections in humans. Furthermore, this virus was shown to be highly pathogenic to both birds and mammals, and demonstrate tropism for the nervous system. Due to the geographical location of Sanmenxia, these novel H5N1 viruses also have the potential to be imported to other regions through the migration of wild birds, similar to the H5N1 outbreak amongst migratory birds in Qinghai Lake during 2005. Therefore, further investigation and monitoring is required to prevent this novel reassortant virus from becoming a new threat to public health.

  7. Persistence of highly pathogenic avian influenza H5N1 virus defined by agro-ecological niche

    Science.gov (United States)

    Hogerwerf, Lenny; Wallace, Rob G.; Ottaviani, Daniela; Slingenbergh, Jan; Prosser, Diann; Bergmann, Luc; Gilbert, Marius

    2010-01-01

    The highly pathogenic avian influenza (HPAI) H5N1 virus has spread across Eurasia and into Africa. Its persistence in a number of countries continues to disrupt poultry production, impairs smallholder livelihoods, and raises the risk a genotype adapted to human-to-human transmission may emerge. While previous studies identified domestic duck reservoirs as a primary risk factor associated with HPAI H5N1 persistence in poultry in Southeast Asia, little is known of such factors in countries with different agro-ecological conditions, and no study has investigated the impact of such conditions on HPAI H5N1 epidemiology at the global scale. This study explores the patterns of HPAI H5N1 persistence worldwide, and for China, Indonesia, and India includes individual provinces that have reported HPAI H5N1 presence during the 2004–2008 period. Multivariate analysis of a set of 14 agricultural, environmental, climatic, and socio-economic factors demonstrates in quantitative terms that a combination of six variables discriminates the areas with human cases and persistence: agricultural population density, duck density, duck by chicken density, chicken density, the product of agricultural population density and chicken output/input ratio, and purchasing power per capita. The analysis identifies five agro-ecological clusters, or niches, representing varying degrees of disease persistence. The agro-ecological distances of all study areas to the medoid of the niche with the greatest number of human cases are used to map HPAI H5N1 risk globally. The results indicate that few countries remain where HPAI H5N1 would likely persist should it be introduced.

  8. Avian Influenza (H5N1) Susceptibility and Receptors in Dogs

    OpenAIRE

    Maas,; Tacken, M.G.J.; Ruuls-van Stalle, E.M.F.; G. Koch; Rooij, De; Stockhofe-Zurwieden, N.

    2007-01-01

    Inoculation of influenza (H5N1) into beagles resulted in virus excretion and rapid seroconversion with no disease. Binding studies that used labeled influenza (H5N1) showed virus attachment to higher and lower respiratory tract tissues. Thus, dogs that are subclinically infected with influenza (H5N1) may contribute to virus spread.

  9. Avian flu : multiple introductions of H5N1 in Nigeria

    NARCIS (Netherlands)

    Ducatez, M F; Olinger, C M; Owoade, A A; De Landtsheer, S; Ammerlaan, W; Niesters, H G M; Osterhaus, A D M E; Fouchier, R A M; Muller, C P

    2006-01-01

    As the avian influenza virus H5N1 swept from Asia across Russia to Europe, Nigeria was the first country in Africa to report the emergence of this highly pathogenic virus. Here we analyse H5N1 sequences in poultry from two different farms in Lagos state and find that three H5N1 lineages were indepen

  10. Avian influenza A virus H5N1 causes autophagy-mediated cell death through suppression of mTOR signaling

    Institute of Scientific and Technical Information of China (English)

    Jianhui Ma; Qian Sun; Ruifang Mi; Hongbing Zhang

    2011-01-01

    Of the few avian influenza viruses that have crossed the species barrier to infect humans,the highly pathogenic influenza A (H5N1) strain has claimed the lives of more than half of the infected patients.With largely unknown mechanism of lung injury by H5N1 infection,acute respiratory distress syndrome (ARDS) is the major cause of death among the victims.Here we present the fact that H5N1 caused autophagic cell death through suppression of mTOR signaling.Inhibition of autophagy,either by depletion of autophagy gene Beclinl or by autophagy inhibitor 3-methyladenine (3-MA),significantly reduced H5N1 mediated cell death.We suggest that autophagic cell death may contribute to the development of ARDS in H5N1 influenza patients and inhibition of autophagy could therefore become a novel strategy for the treatment of H5N1 infection.

  11. Cross-clade protective immune responses to influenza viruses with H5N1 HA and NA elicited by an influenza virus-like particle.

    Directory of Open Access Journals (Sweden)

    Rick A Bright

    Full Text Available BACKGROUND: Vaccination is a cost-effective counter-measure to the threat of seasonal or pandemic outbreaks of influenza. To address the need for improved influenza vaccines and alternatives to egg-based manufacturing, we have engineered an influenza virus-like particle (VLP as a new generation of non-egg or non-mammalian cell culture-based candidate vaccine. METHODOLOGY/PRINCIPAL FINDINGS: We generated from a baculovirus expression system using insect cells, a non-infectious recombinant VLP vaccine from both influenza A H5N1 clade 1 and clade 2 isolates with pandemic potential. VLPs were administered to mice in either a one-dose or two-dose regimen and the immune responses were compared to those induced by recombinant hemagglutinin (rHA. Both humoral and cellular responses were analyzed. Mice vaccinated with VLPs were protected against challenge with lethal reassortant viruses expressing the H5N1 HA and NA, regardless if the H5N1 clade was homologous or heterologous to the vaccine. However, rHA-vaccinated mice showed considerable weight loss and death following challenge with the heterovariant clade virus. Protection against death induced by VLPs was independent of the pre-challenge HAI titer or cell-mediated responses to HA or M1 since vaccinated mice, with low to undetectable cross-clade HAI antibodies or cellular responses to influenza antigens, were still protected from a lethal viral challenge. However, an apparent association rate of antibody binding to HA correlated with protection and was enhanced using VLPs, particularly when delivered intranasally, compared to rHA vaccines. CONCLUSION/SIGNIFICANCE: This is the first report describing the use of an H5N1 VLP vaccine created from a clade 2 isolate. The results show that a non-replicating virus-like particle is effective at eliciting a broadened, cross-clade protective immune response to proteins from emerging H5N1 influenza isolates giving rise to a potential pandemic influenza vaccine

  12. Characterizing wild bird contact and seropositivity to highly pathogenic avian influenza A (H5N1) virus in Alaskan residents.

    Science.gov (United States)

    Reed, Carrie; Bruden, Dana; Byrd, Kathy K; Veguilla, Vic; Bruce, Michael; Hurlburt, Debby; Wang, David; Holiday, Crystal; Hancock, Kathy; Ortiz, Justin R; Klejka, Joe; Katz, Jacqueline M; Uyeki, Timothy M

    2014-09-01

    Highly pathogenic avian influenza A (HPAI) H5N1 viruses have infected poultry and wild birds on three continents with more than 600 reported human cases (59% mortality) since 2003. Wild aquatic birds are the natural reservoir for avian influenza A viruses, and migratory birds have been documented with HPAI H5N1 virus infection. Since 2005, clade 2.2 HPAI H5N1 viruses have spread from Asia to many countries. We conducted a cross-sectional seroepidemiological survey in Anchorage and western Alaska to identify possible behaviors associated with migratory bird exposure and measure seropositivity to HPAI H5N1. We enrolled rural subsistence bird hunters and their families, urban sport hunters, wildlife biologists, and a comparison group without bird contact. We interviewed participants regarding their exposures to wild birds and collected blood to perform serologic testing for antibodies against a clade 2.2 HPAI H5N1 virus strain. Hunters and wildlife biologists reported exposures to wild migratory birds that may confer risk of infection with avian influenza A viruses, although none of the 916 participants had evidence of seropositivity to HPAI H5N1. We characterized wild bird contact among Alaskans and behaviors that may influence risk of infection with avian influenza A viruses. Such knowledge can inform surveillance and risk communication surrounding HPAI H5N1 and other influenza viruses in a population with exposure to wild birds at a crossroads of intercontinental migratory flyways. © 2014 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

  13. 高致病性H5N1型禽流感%The overview of highly pathogenic H5N1 avian influenza

    Institute of Scientific and Technical Information of China (English)

    高维旭; 董芝

    2006-01-01

    目的:高致病性H5N1型禽流感在亚洲的持续爆发引起了人们对全球流感大流行的担心.截至2006年2月,已有160多人被证实感染了H5N1型禽流感,80多人已死亡.本文对H5N1型禽流感的起源,传播,预防及治疗,以及可能的流行情况进行了综述.

  14. Antigenicity and transmissibility of a novel clade 2.3.2.1 avian influenza H5N1 virus.

    Science.gov (United States)

    Xu, Lili; Bao, Linlin; Yuan, Jing; Li, Fengdi; Lv, Qi; Deng, Wei; Xu, Yanfeng; Yao, Yanfeng; Yu, Pin; Chen, Honglin; Yuen, Kwok-Yung; Qin, Chuan

    2013-12-01

    A genetic variant of the H5N1 influenza virus, termed subclade 2.3.2.1, was first identified in Bulgaria in 2010 and has subsequently been found in Vietnam and Laos. Several cases of human infections with this virus have been identified. Thus, it is important to understand the antigenic properties and transmissibility of this variant. Our results showed that, although it is phylogenetically closely related to other previously characterized clade 2.3 viruses, this novel 2.3.2.1 variant exhibited distinct antigenic properties and showed little cross-reactivity to sera raised against other H5N1 viruses. Like other H5N1 viruses, this variant bound preferentially to avian-type receptors, but contained substitutions at positions 190 and 158 of the haemagglutinin (HA) protein that have been postulated to facilitate HA binding to human-type receptors and to enhance viral transmissibility among mammals, respectively. However, this virus did not appear to have acquired the capacity for airborne transmission between ferrets. These findings highlight the challenges in selecting vaccine candidates for H5N1 influenza because these viruses continue to evolve rapidly in the field. It is important to note that some variants have obtained mutations that may gain transmissibility between model animals, and close surveillance of H5N1 viruses in poultry is warranted.

  15. PB2 Segment Promotes High-pathogenicity Of H5N1 Avian Influenza Viruses In Mice

    Directory of Open Access Journals (Sweden)

    Hailiang eSun

    2015-02-01

    Full Text Available H5N1 influenza viruses with high lethality are a continuing threat to humans and poultry. Recently, H5N1 high-pathogenicity avian influenza virus (HPAIV has been shown to transmit through aerosols between ferrets in lab experiments by acquiring some mutation. This is another deeply aggravated threat of H5N1 HPAIV to humans. To further explore the molecular determinant of H5N1 HPAIV virulence in a mammalian model, we compared the virulence of A/Duck/Guangdong/212/2004 (DK212 and A/Quail/Guangdong/90/2004 (QL90. Though they were genetically similar, they had different pathogenicity in mice, as well as their 16 reassortants. The results indicated that a swap of the PB2 gene could dramatically decrease the virulence of rgDK212 in mice (1896-fold but increase the virulence of rgQL90 in mice (60-fold. Furthermore, the polymerase activity assays showed that swapping PB2 genes between these two viruses significantly changed the activity of polymerase complexes in 293T cells. The mutation Ser715Asn in PB2 sharply attenuated the virulence of rgDK212 in mice (2710-fold. PB2 segment promotes high-pathogenicity of H5N1 avian influenza viruses in mice and 715 Ser in PB2 plays an important role in determing high virulence of DK212 in mice.

  16. Evidence for subclinical H5N1 avian influenza infections among Nigerian poultry workers.

    Science.gov (United States)

    Okoye, John O; Eze, Didacus C; Krueger, Whitney S; Heil, Gary L; White, Sarah K; Merrill, Hunter R; Gray, Gregory C

    2014-12-01

    In recent years Nigeria has experienced sporadic incursions of highly pathogenic H5N1 avian influenza among poultry. In 2008, 316 poultry-exposed agricultural workers, and 54 age-group matched non-poultry exposed adults living in the Enugu or Ebonyi States of Nigeria were enrolled and then contacted monthly for 24 months to identify acute influenza-like-illnesses. Annual follow-up sera and questionnaire data were collected at 12 and 24 months. Participants reporting influenza-like illness completed additional questionnaires, and provided nasal and pharyngeal swabs and acute and convalescent sera. Swab and sera specimens were studied for evidence of influenza A virus infection. Sera were examined for elevated antibodies against 12 avian influenza viruses by microneutralization and 3 human viruses by hemagglutination inhibition. Four (3.2%) of the 124 acute influenza-like-illness investigations yielded molecular evidence of influenza, but virus could not be cultured. Serial serum samples from five poultry-exposed subjects had a ≥4-fold change in microneutralization titers against A/CK/Nigeria/07/1132123(H5N1), with three of those having titers ≥1:80 (maximum 1:1,280). Three of the five subjects (60%) reported a preceding influenza-like illness. Hemagglutination inhibition titers were ≥4-fold increases against one of the human viruses in 260 participants. While cross-reactivity from antibodies against other influenza viruses cannot be ruled out as a partial confounder, over the course of the 2-year follow-up, at least 3 of 316 (0.9%) poultry-exposed subjects had evidence for subclinical HPAI H5N1 infections. If these data represent true infections, it seems imperative to increase monitoring for avian influenza among Nigeria's poultry and poultry workers.

  17. H5N1 VLP vaccine induced protection in ferrets against lethal challenge with highly pathogenic H5N1 influenza viruses.

    Science.gov (United States)

    Mahmood, Kutubuddin; Bright, Rick A; Mytle, Nutan; Carter, Donald M; Crevar, Corey J; Achenbach, Jenna E; Heaton, Penny M; Tumpey, Terrence M; Ross, Ted M

    2008-10-03

    In this study, recombinant virus-like particles (VLPs) were evaluated as a candidate vaccine against emerging influenza viruses with pandemic potential. The VLPs are composed of the hemagglutinin (HA), neuraminidase (NA), and matrix 1 (M1) proteins of the H5N1 A/Indonesia/05/2005 (clade 2.1; [Indo/05]) virus, which were expressed using baculovirus in Spodoptera frugiperda (Sf9) cells. Ferrets received either 2 injections of the VLP vaccine at escalating doses (based on HA content), recombinant HA, or were mock vaccinated. Vaccinated ferrets were then challenged with either H5N1 Indo/05 or H5N1 A/Viet Nam 1203/2004 (VN/04) wild-type viruses. All ferrets that received the VLP vaccine survived regardless of the VLP dose or challenge strain, whereas seven of eight mock vaccinated ferrets died. The VLP vaccine induced HAI antibodies against the homologous H5N1 clade 2.1 strain, as well as heterologous strains from H5N1 clades 1, 2.2, and 2.3. The magnitude of the HAI titers correlated with VLP dose. Neutralizing antibody responses against the Indo/05 and VN/04 strains showed a similar pattern. Affinity of the anti-HA antibodies raised by the H5N1 Indo/05 VLPs had a higher association rate to the homologous clade 2.1 HA than to the clade 1 (VN/04) HA; however, once bound, antibodies had similar slow disassociation rates. These results provide support for continued development of the H5N1 VLPs as a candidate vaccine against pandemic influenza. Exploration of immunologic correlates of protection for H5N1 vaccines beyond HAI and neutralizing antibody responses is warranted.

  18. Effect of receptor binding domain mutations on receptor binding and transmissibility of avian influenza H5N1 viruses

    DEFF Research Database (Denmark)

    Maines, Taronna R; Chen, Li-Mei; Van Hoeven, Neal;

    2011-01-01

    Although H5N1 influenza viruses have been responsible for hundreds of human infections, these avian influenza viruses have not fully adapted to the human host. The lack of sustained transmission in humans may be due, in part, to their avian-like receptor preference. Here, we have introduced...

  19. New strategies for the development of H5N1 subtype influenza vaccines: progress and challenges.

    Science.gov (United States)

    Steel, John

    2011-10-01

    The emergence and spread of highly pathogenic avian influenza (H5N1) viruses among poultry in Asia, the Middle East, and Africa have fueled concerns of a possible human pandemic, and spurred efforts towards developing vaccines against H5N1 influenza viruses, as well as improving vaccine production methods. In recent years, promising experimental reverse genetics-derived H5N1 live attenuated vaccines have been generated and characterized, including vaccines that are attenuated through temperature-sensitive mutation, modulation of the interferon antagonist protein, or disruption of the M2 protein. Live attenuated influenza virus vaccines based on each of these modalities have conferred protection against homologous and heterologous challenge in animal models of influenza virus infection. Alternative vaccine strategies that do not require the use of live virus, such as virus-like particle (VLP) and DNA-based vaccines, have also been vigorously pursued in recent years. Studies have demonstrated that influenza VLP vaccination can confer homologous and heterologous protection from lethal challenge in a mouse model of infection. There have also been improvements in the formulation and production of vaccines following concerns over the threat of H5N1 influenza viruses. The use of novel substrates for the growth of vaccine virus stocks has been intensively researched in recent years, and several candidate cell culture-based systems for vaccine amplification have emerged, including production systems based on Madin-Darby canine kidney, Vero, and PerC6 cell lines. Such systems promise increased scalability of product, and reduced reliance on embryonated chicken eggs as a growth substrate. Studies into the use of adjuvants have shown that oil-in-water-based adjuvants can improve the immunogenicity of inactivated influenza vaccines and conserve antigen in such formulations. Finally, efforts to develop more broadly cross-protective immunization strategies through the inclusion

  20. Avian Influenza H5N1 and the Wild Bird Trade in Hanoi, Vietnam

    Directory of Open Access Journals (Sweden)

    F. Brooks-Moizer

    2009-06-01

    Full Text Available Wildlife trade and emerging infectious diseases pose significant threats to human and animal health and global biodiversity. Legal and illegal trade in domestic and wild birds has played a significant role in the global spread of highly pathogenic avian influenza H5N1, which has killed more than 240 people, many millions of poultry, and an unknown number of wild birds and mammals, including endangered species, since 2003. This 2007 study provides evidence for a significant decline in the scale of the wild bird trade in Hanoi since previous surveys in 2000 (39.7% decline and 2003 (74.1% decline. We attribute this to the enforcement of Vietnam's Law 169/2005/QD UBND, introduced in 2005, which prohibits the movement and sale of wild and ornamental birds in cities. Nevertheless, 91.3% (21/23 of bird vendors perceived no risk of H5N1 infection from their birds, and the trade continues, albeit at reduced levels, in open market shops. These findings highlight the importance of continued law enforcement to maintain this trade reduction and the associated benefits to human and animal health and biodiversity conservation.

  1. Metapopulation dynamics enable persistence of influenza A, including A/H5N1, in poultry.

    Directory of Open Access Journals (Sweden)

    Parviez Rana Hosseini

    Full Text Available Highly pathogenic influenza A/H5N1 has persistently but sporadically caused human illness and death since 1997. Yet it is still unclear how this pathogen is able to persist globally. While wild birds seem to be a genetic reservoir for influenza A, they do not seem to be the main source of human illness. Here, we highlight the role that domestic poultry may play in maintaining A/H5N1 globally, using theoretical models of spatial population structure in poultry populations. We find that a metapopulation of moderately sized poultry flocks can sustain the pathogen in a finite poultry population for over two years. Our results suggest that it is possible that moderately intensive backyard farms could sustain the pathogen indefinitely in real systems. This fits a pattern that has been observed from many empirical systems. Rather than just employing standard culling procedures to control the disease, our model suggests ways that poultry production systems may be modified.

  2. Observations from a live bird market in Indonesia following a contained outbreak of avian influenza A (H5N1).

    Science.gov (United States)

    Naysmith, Scott

    2014-01-01

    Live bird markets are considered high-risk environments facilitating viral transfer and replication of influenza A H5N1. In Indonesia, these markets have been the source for multiple human infections of H5N1 resulting in death, and thus have been the focus of government-led interventions. This paper examines the aftermath of an intervention in one market in Bali, Indonesia. It highlights the social and economic factors influencing the adoption of risk prevention behaviour and concludes by arguing for further qualitative research to understand why at-risk individuals fail to adopt biosecurity measures, even after recently experiencing an outbreak of avian influenza.

  3. Design of new inhibitors for H5N1 avian influenza using a molecular dynamics simulation

    Science.gov (United States)

    Park, Jin Woo; Jo, Won Ho

    2008-03-01

    Recently, there has been a growing interest in the treatment of H5N1 avian influenza. One of the most widely used antiviral agents is oseltamivir. However, it has been reported that oseltamivir is not as effective against the neuraminidase subtype N1 as it is against subtypes N2 and N9. In our research we addressed this problem by designing new inhibitors and these altered inhibitor's binding affinities were calculated. In this study, we introduced chemical groups to the existing oseltamivir, so to fit into the newly discovered cavity in the subtype N1. When the binding strengths of the oseltamivir and the newly designed inhibitors for N1 were calculated to examine the drug efficiency through a molecular dynamics simulation, then compared with each other, it was found that one of the designed molecules exhibited a strong binding affinity, with more than twice the binding strength than that of oseltamivir. Since the aforementioned designed inhibitor appears to have the possibility for oral activity according to the criteria of human oral bioavailability, we propose that the inhibitor is a promising antiviral drug for H5N1 avian influenza.

  4. Intranasal Immunization of Mice to Avoid Interference of Maternal Antibody against H5N1 Infection.

    Directory of Open Access Journals (Sweden)

    Fenghua Zhang

    Full Text Available Maternally-derived antibodies (MDAs can protect offspring against influenza virus infection but may also inhibit active immune responses. To overcome MDA- mediated inhibition, active immunization of offspring with an inactivated H5N1 whole-virion vaccine under the influence of MDAs was explored in mice. Female mice were vaccinated twice via the intraperitoneal (IP or intranasal (IN route with the vaccine prior to mating. One week after birth, the offspring were immunized twice via the IP or IN route with the same vaccine and then challenged with a lethal dose of a highly homologous virus strain. The results showed that, no matter which immunization route (IP or IN was used for mothers, the presence of MDAs severely interfered with the active immune response of the offspring when the offspring were immunized via the IP route. Only via the IN immunization route did the offspring overcome the MDA interference. These results suggest that intranasal immunization could be a suitable inoculation route for offspring to overcome MDA interference in the defense against highly pathogenic H5N1 virus infection. This study may provide references for human and animal vaccination to overcome MDA-induced inhibition.

  5. MVA-based H5N1 vaccine affords cross-clade protection in mice against influenz a A/H5N1 viruses at low doses and after single immunization

    NARCIS (Netherlands)

    J.H.C.M. Kreijtz (Joost); Y. Suezer; G. de Mutsert (Gerrie); G. van Amerongen (Geert); A. Scwantes (Astrid); J.M.A. van den Brand (Judith); R.A.M. Fouchier (Ron); J. Löwer; A.D.M.E. Osterhaus (Albert); G. Sutter (Gerd); G.F. Rimmelzwaan (Guus)

    2009-01-01

    textabstractHuman infections with highly pathogenic avian influenza viruses of the H5N1 subtype, frequently reported since 2003, result in high morbidity and mortality. It is feared that these viruses become pandemic, therefore the development of safe and effective vaccines is desirable. MVA-based

  6. Improving global influenza surveillance: trends of A(H5N1 virus in Africa and Asia

    Directory of Open Access Journals (Sweden)

    Escorcia Magdalena

    2012-01-01

    Full Text Available Abstract Background Highly pathogenic avian influenza A(H5N1 viruses are an important health problem in many Asian and African countries. The current increase in human cases demonstrates that influenza A(H5N1 is still a significant global pandemic threat. Many health organizations have recognized the need for new strategies to improve influenza global surveillance. Specifically, the World Health Organization through the global technical consultation for influenza surveillance have called for a detailed picture of the current limitations, especially at the nation level, to evaluate, standardize and strength reporting systems. The main goal of our study is to demonstrate the value of genetic surveillance as part of a strategic surveillance plan. As a proof of concept, we evaluated the current situation of influenza A(H5N1 in Asian and Africa. Results Our analysis revealed a power-law distribution in the number of sequences of A(H5N1 viruses analyzed and/or reported to influenza surveillance networks. The majority of the Asian and African countries at great risk of A(H5N1 infections have very few (approximately three orders of magnitude sequenced A(H5N1 viruses (e.g. hemagglutinin genes. This suggests that countries under pandemic alert for avian influenza A(H5N1 have very limited participation (e.g. data generation, genetic analysis and data share in avian influenza A(H5N1 surveillance. More important, this study demonstrates the usefulness of influenza genetic surveillance to detect emerging pandemic threat viruses. Conclusions Our study reveals that some countries suffering from human cases of avian influenza have limited participation (e.g. genetic surveillance or data share with global surveillance networks. Also, we demonstrate that the implementation of genetic surveillance programs could increase and strengthen worldwide epidemic and pandemic preparedness. We hope that this work promotes new discussions between policy makers and health

  7. Immune escape mutants of Highly Pathogenic Avian Influenza H5N1 selected using polyclonal sera: identification of key amino acids in the HA protein.

    Directory of Open Access Journals (Sweden)

    Ioannis Sitaras

    Full Text Available Evolution of Avian Influenza (AI viruses--especially of the Highly Pathogenic Avian Influenza (HPAI H5N1 subtype--is a major issue for the poultry industry. HPAI H5N1 epidemics are associated with huge economic losses and are sometimes connected to human morbidity and mortality. Vaccination (either as a preventive measure or as a means to control outbreaks is an approach that splits the scientific community, due to the risk of it being a potential driving force in HPAI evolution through the selection of mutants able to escape vaccination-induced immunity. It is therefore essential to study how mutations are selected due to immune pressure. To this effect, we performed an in vitro selection of mutants from HPAI A/turkey/Turkey/1/05 (H5N1, using immune pressure from homologous polyclonal sera. After 42 rounds of selection, we identified 5 amino acid substitutions in the Haemagglutinin (HA protein, most of which were located in areas of antigenic importance and suspected to be prone to selection pressure. We report that most of the mutations took place early in the selection process. Finally, our antigenic cartography studies showed that the antigenic distance between the selected isolates and their parent strain increased with passage number.

  8. Homosubtypic and heterosubtypic antibodies against highly pathogenic avian influenza H5N1 recombinant proteins in H5N1 survivors and non-H5N1 subjects.

    Science.gov (United States)

    Noisumdaeng, Pirom; Pooruk, Phisanu; Prasertsopon, Jarunee; Assanasen, Susan; Kitphati, Rungrueng; Auewarakul, Prasert; Puthavathana, Pilaipan

    2014-04-01

    Six recombinant vaccinia viruses containing HA, NA, NP, M or NS gene insert derived from a highly pathogenic avian influenza H5N1 virus, and the recombinant vaccinia virus harboring plasmid backbone as the virus control were constructed. The recombinant proteins were characterized for their expression and subcellular locations in TK(-) cells. Antibodies to the five recombinant proteins were detected in all 13 sequential serum samples collected from four H5N1 survivors during four years of follow-up; and those directed to rVac-H5 HA and rVac-NA proteins were found in higher titers than those directed to the internal proteins as revealed by indirect immunofluorescence assay. Although all 28 non-H5N1 subjects had no neutralizing antibodies against H5N1 virus, they did have cross-reactive antibodies to those five recombinant proteins. A significant increase in cross-reactive antibody titer to rVac-H5 HA and rVac-NA was found in paired blood samples from patients infected with the 2009 pandemic virus.

  9. A single immunization with HA DNA vaccine by electroporation induces early protection against H5N1 avian influenza virus challenge in mice

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    Chen Jianjun

    2009-02-01

    Full Text Available Abstract Background Developing vaccines for the prevention of human infection by H5N1 influenza viruses is an urgent task. DNA vaccines are a novel alternative to conventional vaccines and should contribute to the prophylaxis of emerging H5N1 virus. In this study, we assessed whether a single immunization with plasmid DNA expressing H5N1 hemagglutinin (HA could provide early protection against lethal challenge in a mouse model. Methods Mice were immunized once with HA DNA at 3, 5, 7 days before a lethal challenge. The survival rate, virus titer in the lungs and change of body weight were assayed to evaluate the protective abilities of the vaccine. To test the humoral immune response induced by HA DNA, serum samples were collected through the eye canthus of mice on various days after immunization and examined for specific antibodies by ELISA and an HI assay. Splenocytes were isolated after the immunization to determine the antigen-specific T-cell response by the ELISPOT assay. Results Challenge experiments revealed that a single immunization of H5N1 virus HA DNA is effective in early protection against lethal homologous virus. Immunological analysis showed that an antigen-specific antibody and T-cell response could be elicited in mice shortly after the immunization. The protective abilities were correlated with the amount of injected DNA and the length of time after vaccination. Conclusion A single immunization of 100 μg H5 HA DNA vaccine combined with electroporation was able to provide early protection in mice against homologous virus infection.

  10. Asymptomatic infection with highly pathogenic avian influenza H5N1 in wild birds: how sound is the evidence?

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    Yasué Maï

    2006-11-01

    Full Text Available Abstract Background Widespread deaths of wild birds from which highly pathogenic avian influenza virus H5N1 has been isolated suggest that the virus continues to be lethal to them. However, asymptomatic carriage by some wild birds could allow birds to spread the virus on migration. Confirmation of such carriage is therefore important for the design of mitigation measures for the disease in poultry. Discussion Two recent papers have reported the isolation of H5N1 from a small number of water birds in China and Russia and have concluded that wild birds can spread the viruses over long distances on migration. However, both papers contain weaknesses in the provision of ornithological and associated data that compromise conclusions that can be reached about the role of wild birds in the spread of H5N1. We describe the weaknesses of these studies and highlight the need for improved methodological description and methodology, where appropriate, and further research. Summary A rigorous assessment of whether wild birds can carry H5N1 asymptomatically is critical to evaluating the risks of spread by migratory birds on long-distance migration.

  11. Multiplex Reverse Transcription-Polymerase Chain Reaction untuk Deteksi Cepat Virus Flu Burung H5N1 (MULTIPLEX REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION FOR RAPID DETECTION OF H5N1 AVIAN INFLUENZA VIRUS

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    Raden Wasito

    2015-05-01

    Full Text Available Avian influenza virus subtype H5N1 (AIV H5N1 is highly pathogenic and fatal in poultry. The virusis still endemic with low virulence rate, although it may play a critical role in causing high morbidity andmortality rates in poultry in Indonesia. In general, diagnostic approach for AIV H5N1 is based onconventional serological and viral isolation methods that have the potential to produce consumings oftime and relatively expensive cost within the laboratory without compromising test utility. Thus, amolecular approach of multiplex reverse transcription-polymerase chain reaction (mRT-PCR was developedand applied for the detection of matrix gene type A influenza viruses, AIV subtype subtype H5hemagglutinin gene with simultaneous detection of N1 nucleoprotein gene. Thirty sera specimens fromthe diseased commercial chickens that were specifically amplified positive-RT-PCR for AIV H5N1 wereselected for mRT-PCR. The mRT-PCR products were visualized by agarose gel electrophoresis and consistedof DNA fragments of AIV of 245 bp, 545 bp and 343 bp for M, H5 and N1 genes, respectively. Thus, themRT-PCR that can rapidly differentiate simultaneously between these genes is very important for thecontrol and even eradication of AIV transmission in poultry in Indonesia.

  12. Detection of Markers of Increased Virulence Non Structural protein (NS I Avian Influenza Virus H5N1 from Indonesia=DETEKSI PENANDA PENINGKATAN VIRULENSI NON STRUKTURAL PROTEIN (NS1 VIRUS AVIAN INFLUENZA H5N1 ASAL INDONESIA

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    Arief Mulyono

    2015-03-01

    Full Text Available ENGLISHAbstractNS1 protein is a multifunction protein that plays key role of pathogenesis and virulence of avians influenza virus H5N1. The amino acid substitution at the position P42S, D92E, F103I, M106I and 5 amino acid deletion at the position 80 to 84 in NS1 protein reported increasing virulence of avians influenza virus H5N1. Several studies showed avians influenza virus H5N1 in Indonesia has dynamic changed. This study aimed to analyze the markers of virulence of NS1 protein sequences of all H5N1 virus isolates from Indonesia. The source of NS1 protein sequence data gene obtained from GeneBank and Gisaid. Data were analyzed using Bioedit software. The Results showed the isolates from Indonesia had substitutions P42S and 5 amino acids deletions at positions 80-84 resulting in the potential for increased virulence of the virus. However, amino acid substitution at the position D92E, F103L and M106I substitution were not found.INDONESIANAbstrakProtein NS1 adalah protein multifungsi yang memainkan peran kunci dalam patogenesis dan virulensi virus avian influenza H5N1. Substitusi asam amino P42S, D92E, F103I, M106I, dan delesi 5 asam amino di posisi 80 - 84 dilaporkan meningkatkan virulensi virus avian influenza H5N1. Beberapa penelitian menunjukkan bahwa virus avian influenza di Indonesia mengalami perubahan dinamis. Studi ini akan menganalisis motif asam amino yang menjadi penanda peningkatan virulensi pada sekuen protein NS1 virus avian influenza H5N1 asal Indonesia. Data sekuen asam amino protein NS1 diperoleh dari database GeneBank dan Gisaid. Analisis data menggunakan Bioedit software. Hasil analisis menunjukkan subtitusi asam amino dari prolin ke serin di posisi 42 (P42S dan delesi 5 asam amino di posisi 80 – 84 telah ditemukan pada virus avian influenza asal Indonesia, akan tetapi tidak ditemukan substitusi asam amino aspartat ke glutamat diposisi no 92 (D92E dan tidak ada yang mengalami 2 substitusi asam amino sekaligus diposisi 103

  13. Highly pathogenic avian influenza A (H5N1) virus in wildlife: diagnostics, epidemiology and molecular characteristics

    NARCIS (Netherlands)

    Keawcharoen, J.

    2010-01-01

    Since 2003, highly pathogenic avian influenza virus subtype H5N1 outbreaks have been reported in Southeast Asia causing high mortality in poultry and have also been found to cross the species barrier infecting human and other mammalian species. Thailand is one of the countries severely affected by t

  14. Influenza A aviária (H5N1: a gripe do frango Avian influenza A (H5N1: the bird flu

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    Cássio da Cunha Ibiapina

    2005-10-01

    conducted using the Medline, MD Consult, HighWire, Medscape and Literatura Latinoamericana y del Caribe en Ciencias de la Salud (LILACS, Latin American and Caribbean Health Sciences Literature databases, as well as through direct research, limiting the scope to articles published within the past 10 years. We selected 31 original articles addressing the recent outbreaks of infection with the H5N1 subtype of avian influenza A in domesticated birds in Asia, which have resulted in significant economic losses and repercussions for public health, as well as some cases of human infection presenting high lethality. In most cases, infection has been associated with direct exposure to infected birds or contact with surfaces infected with bird excrement. However, cases of human-to-human transmission have been confirmed. In those cases, the incubation period varied from 2 to 4 days. The clinical manifestations range from asymptomatic infection to mild upper airway disease, pneumonia and multiple organ failure. Chest X-rays may reveal bilateral interstitial infiltrate, lobar collapse, focal consolidation and air bronchogram without pleural effusion. Lymphopenia is indicative of a poor prognosis. Supportive care appears to be the only acceptable treatment. Risk factors for poor prognosis include advanced age, delayed hospitalization, lower airway involvement, low white blood cell count or lymphopenia upon admission. Controlling outbreaks in domestic fowl and limiting contact between humans and infected birds must be the priorities in the management of this disease at the public health level. In addition, techniques and knowledge regarding the disease should be widely disseminated.

  15. Protective efficacy of an H5N1 DNA vaccine against challenge with a lethal H5N1 virus in quail.

    Science.gov (United States)

    Li, Junping; Jiang, Yongping; Zhao, Shuangcheng; Chang, Xiaofei; Liu, Jinxiong; Zeng, Xianying; Li, Yanbing; Chen, Hualan

    2012-12-01

    Some H5N1 avian influenza viruses (AIVs) are lethal to quail; however, the use of inactivated vaccines in these birds is largely restricted because of side effects caused by oil adjuvants. Here we evaluated the protective efficacy of a DNA vaccine against lethal challenge with H5N1 highly pathogenic avian influenza virus (HPAIV) in quail. Groups of ten 3-wk-old quail were intramuscularly inoculated three times at 3-wk intervals with 10, 15, 30, or 60 microg, respectively, of plasmid pCAGGoptiHA, which expresses a codon-optimized hemagglutinin gene of the H5N1 virus A/goose/Guangdong/1/96 (GS/GD/96). The control group was inoculated with phosphate-buffered saline. Hemagglutination-inhibition (HI) antibodies were monitored every week after the primary vaccination. The quail were challenged intranasally with 10(5) EID50 of heterologous HPAIV A/duck/Fujian/31/2007 (DK/ FJ/31) (H5N1) 2 wk after the third inoculation. Oropharyngeal and cloacal swab specimens were collected 3, 5, and 7 days after inoculation, and quail were observed daily for disease signs and death for 2 wk. The quail showed no side effects after the plasmid inoculation, and HI antibodies were detectable 1 wk after the second vaccination in all groups and increased sharply after the third inoculation. All quail in the PBS-inoculated group and 20% of the birds in the 10 microg plasmid-inoculated group died after the lethal H5N1 virus challenge; however, birds in the 15, 30, and 60 jg plasmid-inoculated groups were completely protected. These results indicate that this DNA vaccine holds promise for use in quail to protect against H5N1 AIV.

  16. An RNA conformational shift in recent H5N1 influenza A viruses

    NARCIS (Netherlands)

    Gultyaev, A.P.; Heus, H.A.; Olsthoorn, R.C.

    2007-01-01

    Recent outbreaks of avian influenza are being caused by unusually virulent H5N1 strains. It is unknown what makes these recent H5N1 strains more aggressive than previously circulating strains. Here, we have compared more than 3000 RNA sequences of segment 8 of type A influenza viruses and found a un

  17. Genetic versus antigenic differences among highly pathogenic H5N1 avian influenza A viruses

    NARCIS (Netherlands)

    Peeters, Ben; Reemers, Sylvia; Dortmans, Jos; Vries, de Erik; Jong, de Mart; Zande, van de Saskia; Rottier, Peter J.M.; Haan, de Cornelis A.M.

    2017-01-01

    Highly pathogenic H5N1 avian influenza A viruses display a remarkable genetic and antigenic diversity. We examined to what extent genetic distances between several H5N1 viruses from different clades correlate with antigenic differences and vaccine performance. H5-specific antisera were generated, an

  18. Virulence of H5N1 Influenza Virus in Cattle Egrets (Bubulcus Ibis)

    DEFF Research Database (Denmark)

    Phuong, Do Quy; Dung, Nguyen Tien; Jørgensen, Poul Henrik

    2011-01-01

    for insect control in households. In this study, six Cattle Egrets were experimentally infected intranasally with highly pathogenic avian influenza (AI) A/duck/Vietnam/40D/04 (H5N1) to investigate a possible epidemiologic role for Cattle Egrets in outbreaks of H5N1 AI in Vietnam. The Cattle Egrets were...

  19. MVA-based H5N1 vaccine affords cross-clade protection in mice against influenza A/H5N1 viruses at low doses and after single immunization.

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    Joost H C M Kreijtz

    Full Text Available Human infections with highly pathogenic avian influenza viruses of the H5N1 subtype, frequently reported since 2003, result in high morbidity and mortality. It is feared that these viruses become pandemic, therefore the development of safe and effective vaccines is desirable. MVA-based H5N1 vaccines already proved to be effective when two immunizations with high doses were used. Dose-sparing strategies would increase the number of people that can be vaccinated when the amount of vaccine preparations that can be produced is limited. Furthermore, protective immunity is induced ideally after a single immunization. Therefore the minimal requirements for induction of protective immunity with a MVA-based H5N1 vaccine were assessed in mice. To this end, mice were vaccinated once or twice with descending doses of a recombinant MVA expressing the HA gene of influenza virus A/Vietnam/1194/04. The protective efficacy was determined after challenge infection with the homologous clade 1 virus and a heterologous virus derived from clade 2.1, A/Indonesia/5/05 by assessing weight loss, virus replication and histopathological changes. It was concluded that MVA-based vaccines allowed significant dose-sparing and afford cross-clade protection, also after a single immunization, which are favorable properties for an H5N1 vaccine candidate.

  20. Simultaneous detection and differentiation by multiplex real time RT-PCR of highly pathogenic avian influenza subtype H5N1 classic (clade 2.2.1 proper and escape mutant (clade 2.2.1 variant lineages in Egypt

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    Arafa Abdel-Satar

    2010-10-01

    Full Text Available Abstract Background The endemic status of highly pathogenic avian influenza virus (HPAIV of subtype H5N1 in Egypt continues to devastate the local poultry industry and poses a permanent threat for human health. Several genetically and antigenically distinct H5N1 lineages co-circulate in Egypt: Strains of clade 2.2.1 proper replicate mainly in backyard birds causing the bulk of human infections, while a variant lineage within 2.2.1 (2.2.1v appears to be perpetuated mainly in commercial poultry farms in Egypt. Viruses of the 2.2.1v lineage represent drift variants escaping from conventional vaccine-induced immunity and some of these strains also escaped detection by commercial real time reverse transcriptase PCR (RT-qPCR protocols due to mismatches in the primers/probe binding sites. Results We developed therefore a versatile, sensitive and lineage-specific multiplex RT-qPCR for detection and typing of H5N1 viruses in Egypt. Analytical characterization was carried out using 50 Egyptian HPAIV H5N1 strains isolated since 2006 and 45 other avian influenza viruses (AIV. A detection limit of 400 cRNA copies per ml sample matrix was found. Higher diagnostic sensitivity of the multiplex assay in comparison to other generic H5 or M-gene based RT-qPCR assays were found by examination of 63 swab samples from experimentally infected chickens and 50 AIV-positive swab samples from different host species in the field in Egypt. Conclusions The new multiplex RT-qPCR assay could be useful for rapid high-throughput monitoring for the presence of HPAIV H5N1 in commercial poultry in Egypt. It may also aid in prospective epidemiological studies to further delineate and better control spread of HPAIV H5N1 in Egypt.

  1. Cross-protection against lethal H5N1 challenge in ferrets with an adjuvanted pandemic influenza vaccine.

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    Benoît Baras

    Full Text Available BACKGROUND: Unprecedented spread between birds and mammals of highly pathogenic avian influenza viruses (HPAI of the H5N1 subtype has resulted in hundreds of human infections with a high fatality rate. This has highlighted the urgent need for the development of H5N1 vaccines that can be produced rapidly and in sufficient quantities. Potential pandemic inactivated vaccines will ideally induce substantial intra-subtypic cross-protection in humans to warrant the option of use, either prior to or just after the start of a pandemic outbreak. In the present study, we evaluated a split H5N1 A/H5N1/Vietnam/1194/04, clade 1 candidate vaccine, adjuvanted with a proprietary oil-in- water emulsion based Adjuvant System proven to be well-tolerated and highly immunogenic in the human (Leroux-Roels et al. (2007 The Lancet 370:580-589, for its ability to induce intra-subtypic cross-protection against clade 2 H5N1/A/Indonesia/5/05 challenge in ferrets. METHODOLOGY AND PRINCIPAL FINDINGS: All ferrets in control groups receiving non-adjuvanted vaccine or adjuvant alone failed to develop specific or cross-reactive neutralizing antibodies and all died or had to be euthanized within four days of virus challenge. Two doses of adjuvanted split H5N1 vaccine containing >or=1.7 microg HA induced neutralizing antibodies in the majority of ferrets to both clade 1 (17/23 (74% responders and clade 2 viruses (14/23 (61% responders, and 96% (22/23 of vaccinees survived the lethal challenge. Furthermore lung virus loads and viral shedding in the upper respiratory tract were reduced in vaccinated animals relative to controls suggesting that vaccination might also confer a reduced risk of viral transmission. CONCLUSION: These protection data in a stringent challenge model in association with an excellent clinical profile highlight the potential of this adjuvanted H5N1 candidate vaccine as an effective tool in pandemic preparedness.

  2. Avian Influenza (H5N1) Warning System using Dempster-Shafer Theory and Web Mapping

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    Maseleno, Andino

    2012-01-01

    Based on Cumulative Number of Confirmed Human Cases of Avian Influenza (H5N1) Reported to World Health Organization (WHO) in the 2011 from 15 countries, Indonesia has the largest number death because Avian Influenza which 146 deaths. In this research, the researcher built a Web Mapping and Dempster-Shafer theory as early warning system of avian influenza. Early warning is the provision of timely and effective information, through identified institutions, that allows individuals exposed to a hazard to take action to avoid or reduce their risk and prepare for effective response. In this paper as example we use five symptoms as major symptoms which include depression, combs, wattle, bluish face region, swollen face region, narrowness of eyes, and balance disorders. Research location is in the Lampung Province, South Sumatera. The researcher reason to choose Lampung Province in South Sumatera on the basis that has a high poultry population. Geographically, Lampung province is located at 103040' to 105050' East Lo...

  3. Adaptation of high-growth influenza H5N1 vaccine virus in Vero cells: implications for pandemic preparedness.

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    Yu-Fen Tseng

    Full Text Available Current egg-based influenza vaccine production technology can't promptly meet the global demand during an influenza pandemic as shown in the 2009 H1N1 pandemic. Moreover, its manufacturing capacity would be vulnerable during pandemics caused by highly pathogenic avian influenza viruses. Therefore, vaccine production using mammalian cell technology is becoming attractive. Current influenza H5N1 vaccine strain (NIBRG-14, a reassortant virus between A/Vietnam/1194/2004 (H5N1 virus and egg-adapted high-growth A/PR/8/1934 virus, could grow efficiently in eggs and MDCK cells but not Vero cells which is the most popular cell line for manufacturing human vaccines. After serial passages and plaque purifications of the NIBRG-14 vaccine virus in Vero cells, one high-growth virus strain (Vero-15 was generated and can grow over 10(8 TCID(50/ml. In conclusion, one high-growth H5N1 vaccine virus was generated in Vero cells, which can be used to manufacture influenza H5N1 vaccines and prepare reassortant vaccine viruses for other influenza A subtypes.

  4. Construction of a Chimeric Secretory IgA and Its Neutralization Activity against Avian Influenza Virus H5N1

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    Cun Li

    2014-01-01

    Full Text Available Secretory immunoglobulin A (SIgA acts as the first line of defense against respiratory pathogens. In this assay, the variable regions of heavy chain (VH and Light chain (VL genes from a mouse monoclonal antibody against H5N1 were cloned and fused with human IgA constant regions. The full-length chimeric light and heavy chains were inserted into a eukaryotic expressing vector and then transfected into CHO/dhfr-cells. The chimeric monomeric IgA antibody expression was confirmed by using ELISA, SDS-PAGE, and Western blot. In order to obtain a dimeric secretory IgA, another two expressing plasmids, namely, pcDNA4/His A-IgJ and pcDNA4/His A-SC, were cotransfected into the CHO/dhfr-cells. The expression of dimeric SIgA was confirmed by using ELISA assay and native gel electrophoresis. In microneutralization assay on 96-well immunoplate, the chimeric SIgA showed neutralization activity against H5N1 virus on MDCK cells and the titer was determined to be 1 : 64. On preadministrating intranasally, the chimeric SIgA could prevent mice from lethal attack by using A/Vietnam/1194/04 H5N1 with a survival rate of 80%. So we concluded that the constructed recombinant chimeric SIgA has a neutralization capability targeting avian influenza virus H5N1 infection in vitro and in vivo.

  5. Risk factors for highly pathogenic avian influenza (HPAI) H5N1 infection in backyard chicken farms, Thailand.

    Science.gov (United States)

    Paul, Mathilde; Wongnarkpet, Sirichai; Gasqui, Patrick; Poolkhet, Chaithep; Thongratsakul, Sukanya; Ducrot, Christian; Roger, François

    2011-06-01

    To reduce the risk of highly pathogenic avian influenza (HPAI) H5N1 infection in humans, the pathways by which HPAI is spread in poultry must be determined. Backyard poultry farmers are particularly vulnerable to the threat of HPAI, with both their health and livelihoods at risk. Identifying the risk factors for HPAI infection in backyard farms should allow control measures to be better targeted. To study the risk factors of HPAI H5N1 infection, we carried out a case-control study on backyard chicken farms in Thailand, analyzing 104 case farms and 382 control farms. Data on farming practices and environmental characteristics were analyzed using multivariate logistic regression models. We show that farms where owners bought live chickens from another backyard farm had a higher risk of HPAI H5N1 infection (OR 3.34, 95% CI 1.72-6.47), while those where owners used a disinfectant to clean poultry areas were exposed to lower risk (OR 0.48, 95% CI 0.26-0.87). Our results highlight the important role of the trade of poultry between farms in the transmission of HPAI H5N1, in addition to farming practices and environmental characteristics. Findings from this study may help to tailor prevention measures to the local circumstances of backyard farms in different regions of the world.

  6. Oral priming with replicating adenovirus serotype 4 followed by subunit H5N1 vaccine boost promotes antibody affinity maturation and expands H5N1 cross-clade neutralization.

    Science.gov (United States)

    Khurana, Surender; Coyle, Elizabeth M; Manischewitz, Jody; King, Lisa R; Ishioka, Glenn; Alexander, Jeff; Smith, Jon; Gurwith, Marc; Golding, Hana

    2015-01-01

    A Phase I trial conducted in 2009-2010 demonstrated that oral vaccination with a replication competent Ad4-H5 (A/Vietnam) vector with dosages ranging from 107-1011 viral particles was well tolerated. HA-specific T-cell responses were efficiently induced, but very limited hemagglutination-inhibiting (HI) humoral responses were measured. However, a single boost of Ad4-H5-Vtn vaccinated individuals with a unadjuvanted licensed H5N1 (A/Vietnam) subunit vaccine resulted in superior HI titers compared with unprimed subjects. In the current study, the impact of Ad4-H5 priming on the quality of the polyclonal humoral immune response was evaluated using a real-time kinetics assay by surface plasmon resonance (SPR). Total binding of serum polyclonal antibodies from the Ad4-H5-Vtn primed groups against both homologous H5N1-A/Vietnam/1194/2004 (clade 1) and heterologous A/Indonesia-5/2005 (clade 2.1) HA1 head domain was significantly higher compared with sera from individuals that received subunit H5N1 vaccination alone. SPR measurements also demonstrated that the antigen-antibody complex dissociation rates (a surrogate for antibody affinity) of serum antibodies against the HA1 of H5N1-A/Vietnam were significantly higher in the Ad4-H5 primed groups compared with those from the unprimed group. Furthermore, strong correlations were observed between the antibody affinities for HA1 (but not HA2) and the virus neutralization titers against the homologous strain and a panel of heterologous clade 2 H5N1 strains. These findings support the concept of oral prime-boost vaccine approaches against pandemic influenza to elicit long-term memory B cells with high affinity capable of rapid response to variant pandemic viruses likely to emerge and adapt to human transmissions.

  7. Oral priming with replicating adenovirus serotype 4 followed by subunit H5N1 vaccine boost promotes antibody affinity maturation and expands H5N1 cross-clade neutralization.

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    Surender Khurana

    Full Text Available A Phase I trial conducted in 2009-2010 demonstrated that oral vaccination with a replication competent Ad4-H5 (A/Vietnam vector with dosages ranging from 107-1011 viral particles was well tolerated. HA-specific T-cell responses were efficiently induced, but very limited hemagglutination-inhibiting (HI humoral responses were measured. However, a single boost of Ad4-H5-Vtn vaccinated individuals with a unadjuvanted licensed H5N1 (A/Vietnam subunit vaccine resulted in superior HI titers compared with unprimed subjects. In the current study, the impact of Ad4-H5 priming on the quality of the polyclonal humoral immune response was evaluated using a real-time kinetics assay by surface plasmon resonance (SPR. Total binding of serum polyclonal antibodies from the Ad4-H5-Vtn primed groups against both homologous H5N1-A/Vietnam/1194/2004 (clade 1 and heterologous A/Indonesia-5/2005 (clade 2.1 HA1 head domain was significantly higher compared with sera from individuals that received subunit H5N1 vaccination alone. SPR measurements also demonstrated that the antigen-antibody complex dissociation rates (a surrogate for antibody affinity of serum antibodies against the HA1 of H5N1-A/Vietnam were significantly higher in the Ad4-H5 primed groups compared with those from the unprimed group. Furthermore, strong correlations were observed between the antibody affinities for HA1 (but not HA2 and the virus neutralization titers against the homologous strain and a panel of heterologous clade 2 H5N1 strains. These findings support the concept of oral prime-boost vaccine approaches against pandemic influenza to elicit long-term memory B cells with high affinity capable of rapid response to variant pandemic viruses likely to emerge and adapt to human transmissions.

  8. Lemna (duckweed) expressed hemagglutinin from avian influenza H5N1 protects chickens against H5N1 high pathogenicity avian influenza virus challenge

    Science.gov (United States)

    In the last two decades, transgenic plants have been explored as safe and cost effective alternative expression platforms for producing recombinant proteins. In this study, a synthetic hemagglutinin (HA) gene from the high pathogenicity avian influenza (HPAI) virus A/chicken/Indonesia/7/2003 (H5N1)...

  9. Vaccine Design for H5N1 Based on B- and T-cell Epitope Predictions.

    Science.gov (United States)

    Tambunan, Usman Sumo Friend; Sipahutar, Feimmy Ruth Pratiwi; Parikesit, Arli Aditya; Kerami, Djati

    2016-01-01

    From 2003 to 2013, Indonesia had the highest number of avian influenza A cases in humans, with 192 cases and 160 fatalities. Avian influenza is caused by influenza virus type A, such as subtype H5N1. This virus has two glycoproteins: hemagglutinin and neuraminidase, which will become the primary target to be neutralized by vaccine. Vaccine is the most effective immunologic intervention. In this study, we use the epitope-based vaccine design from hemagglutinin and neuraminidase of H5N1 Indonesian strain virus by using immunoinformatics approach in order to predict the binding of B-cell and T-cell epitopes (class I and class II human leukocyte antigen [HLA]). BCPREDS was used to predict the B-cell epitope. Propred, Propred I, netMHCpan, and netMHCIIpan were used to predict the T-cell epitope. Two B-cell epitopes of hemagglutinin candidates and one B-cell epitope of neuraminidase candidates were obtained to bind T-cell CD4(+) (class II HLA), and also five T-cell epitope hemagglutinin and four T-cell epitope neuraminidase were obtained to bind T-cell CD8(+) (class I HLA). The visualization of epitopes was done using MOE 2008.10. It shows that the binding affinity of epitope-HLA was based on minimum binding free energy (ΔG binding). Based on this result, visualization, and dynamic simulation, four hemagglutinin epitopes (MEKIVLLLA, CPYLGSPSF, KCQTPMGAI, and IGTSTLNQR) and two neuraminidase epitopes (NPNQKIITI and CYPDAGEIT) were computed as having the best binding affinity from HLA ligand. The results mentioned above are from in silico experiments and need to be validated using wet experiment.

  10. A unique influenza A (H5N1 virus causing a focal poultry outbreak in 2007 in Manipur, India

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    Raut Satish

    2009-02-01

    Full Text Available Abstract Background A focal H5N1 outbreak in poultry was reported from Manipur, a north-eastern state, of India, in 2007. The aim of this study was to genetically characterize the Manipur isolate to understand the relationship with other H5N1 isolates and to trace the possible source of introduction of the virus into the country. Results Characterization of the complete genome revealed that the virus belonged to clade 2.2. It was distinctly different from viruses of the three EMA sublineages of clade 2.2 but related to isolates from wild migratory waterfowl from Russia, China and Mongolia. The HA gene, had the cleavage site GERRRRKR, earlier reported in whooper swan isolates from Mongolia in 2005. A stop codon at position 29 in the PB1-F2 protein could have implications on the replication efficiency. The acquisition of polymorphisms as seen in recent isolates of 2005–07 from distinct geographical regions suggests the possibility of transportation of H5N1 viruses through migratory birds. Conclusion Considering that all eight genes of the earlier Indian isolates belonged to the EMA3 sublineage and similar strains have not been reported from neighbouring countries of the subcontinent, it appears that the virus may have been introduced independently.

  11. X-ray structure of NS1 from a highly pathogenic H5N1 influenza virus

    Energy Technology Data Exchange (ETDEWEB)

    Bornholdt, Zachary A.; Prasad, B.V. Venkataram (Baylor)

    2009-04-08

    The recent emergence of highly pathogenic avian (H5N1) influenza viruses, their epizootic and panzootic nature, and their association with lethal human infections have raised significant global health concerns. Several studies have underlined the importance of non-structural protein NS1 in the increased pathogenicity and virulence of these strains. NS1, which consists of two domains - a double-stranded RNA (dsRNA) binding domain and the effector domain, separated through a linker - is an antagonist of antiviral type-I interferon response in the host. Here we report the X-ray structure of the full-length NS1 from an H5N1 strain (A/Vietnam/1203/2004) that was associated with 60% of human deaths in an outbreak in Vietnam. Compared to the individually determined structures of the RNA binding domain and the effector domain from non-H5N1 strains, the RNA binding domain within H5N1 NS1 exhibits modest structural changes, while the H5N1 effector domain shows significant alteration, particularly in the dimeric interface. Although both domains in the full-length NS1 individually participate in dimeric interactions, an unexpected finding is that these interactions result in the formation of a chain of NS1 molecules instead of distinct dimeric units. Three such chains in the crystal interact with one another extensively to form a tubular organization of similar dimensions to that observed in the cryo-electron microscopy images of NS1 in the presence of dsRNA. The tubular oligomeric organization of NS1, in which residues implicated in dsRNA binding face a 20-{angstrom}-wide central tunnel, provides a plausible mechanism for how NS1 sequesters varying lengths of dsRNA, to counter cellular antiviral dsRNA response pathways, while simultaneously interacting with other cellular ligands during an infection.

  12. H5N1 病毒感染及其防治现状

    Institute of Scientific and Technical Information of China (English)

    孙丽萍; 马静

    2007-01-01

    @@ 高致病性禽流感病毒-H5N1(Avian Influenza A Virus-H5N1)不仅影响了家禽,而且已经跨越种属障碍,感染人类,并导致许多病例病死.H5N1 病毒感染的流行尚未得到有效控制,还在呈范围不断扩大、感染动物种类增加的态势.本文综合有关文献,对人 H5N1 病毒感染的一些特征、临床病例处置以及 H5N1 病毒研究进展[1],以及人 H5N1 病毒感染防治措施进行了梳理,旨在探讨加强人 H5N1 病毒感染的预防与控制.

  13. Endothelial cell tropism is a determinant of H5N1 pathogenesis in mammalian species.

    Directory of Open Access Journals (Sweden)

    Smanla Tundup

    2017-03-01

    Full Text Available The cellular and molecular mechanisms underpinning the unusually high virulence of highly pathogenic avian influenza H5N1 viruses in mammalian species remains unknown. Here, we investigated if the cell tropism of H5N1 virus is a determinant of enhanced virulence in mammalian species. We engineered H5N1 viruses with restricted cell tropism through the exploitation of cell type-specific microRNA expression by incorporating microRNA target sites into the viral genome. Restriction of H5N1 replication in endothelial cells via miR-126 ameliorated disease symptoms, prevented systemic viral spread and limited mortality, despite showing similar levels of peak viral replication in the lungs as compared to control virus-infected mice. Similarly, restriction of H5N1 replication in endothelial cells resulted in ameliorated disease symptoms and decreased viral spread in ferrets. Our studies demonstrate that H5N1 infection of endothelial cells results in excessive production of cytokines and reduces endothelial barrier integrity in the lungs, which culminates in vascular leakage and viral pneumonia. Importantly, our studies suggest a need for a combinational therapy that targets viral components, suppresses host immune responses, and improves endothelial barrier integrity for the treatment of highly pathogenic H5N1 virus infections.

  14. Flying over an infected landscape: distribution of highly pathogenic avian influenza H5N1 risk in South Asia and satellite tracking of wild waterfowl

    Science.gov (United States)

    Gilbert, Marius; Newman, Scott H.; Takekawa, John Y.; Loth, Leo; Biradar, Chandrashekhar; Prosser, Diann J.; Balachandran, Sivananinthaperumal; Rao, Mandava Venkata Subba; Mundkur, Taej; Yan, Baoping; Xing, Zhi; Hou, Yuansheng; Batbayar, Nyambayar; Tseveenmayadag, Natsagdorj; Hogerwerf, Lenny; Slingenbergh, Jan; Xiao, Xiangming

    2010-01-01

    Highly pathogenic avian influenza (HPAI) H5N1 virus persists in Asia, posing a threat to poultry, wild birds, and humans. Previous work in Southeast Asia demonstrated that HPAI H5N1 risk is related to domestic ducks and people. Other studies discussed the role of migratory birds in the long distance spread of HPAI H5N1. However, the interplay between local persistence and long-distance dispersal has never been studied. We expand previous geospatial risk analysis to include South and Southeast Asia, and integrate the analysis with migration data of satellite-tracked wild waterfowl along the Central Asia flyway. We find that the population of domestic duck is the main factor delineating areas at risk of HPAI H5N1 spread in domestic poultry in South Asia, and that other risk factors, such as human population and chicken density, are associated with HPAI H5N1 risk within those areas. We also find that satellite tracked birds (Ruddy Shelduck and two Bar-headed Geese) reveal a direct spatio-temporal link between the HPAI H5N1 hot-spots identified in India and Bangladesh through our risk model, and the wild bird outbreaks in May,June,July 2009 in China(Qinghai Lake), Mongolia, and Russia. This suggests that the continental-scale dynamics of HPAI H5N1 are structured as a number of persistence areas delineated by domestic ducks, connected by rare transmission through migratory waterfowl.

  15. Highly Pathogenic Reassortant Avian Influenza A(H5N1) Virus Clade 2.3.2.1a in Poultry, Bhutan

    Science.gov (United States)

    Marinova-Petkova, Atanaska; Franks, John; Tenzin, Sangay; Dahal, Narapati; Dukpa, Kinzang; Dorjee, Jambay; Feeroz, Mohammed M.; Rehg, Jerold E.; Barman, Subrata; Krauss, Scott; McKenzie, Pamela; Webby, Richard J.

    2016-01-01

    Highly pathogenic avian influenza A(H5N1), clade 2.3.2.1a, with an H9-like polymerase basic protein 1 gene, isolated in Bhutan in 2012, replicated faster in vitro than its H5N1 parental genotype and was transmitted more efficiently in a chicken model. These properties likely help limit/eradicate outbreaks, combined with strict control measures. PMID:27584733

  16. Avian Influenza A(H5N1) Virus Outbreak Investigation: Application of the FAO-OIE-WHO Four-way Linking Framework in Indonesia.

    Science.gov (United States)

    Setiawaty, V; Dharmayanti, N L P I; Misriyah; Pawestri, H A; Azhar, M; Tallis, G; Schoonman, L; Samaan, G

    2015-08-01

    WHO, FAO and OIE developed a 'four-way linking' framework to enhance the cross-sectoral sharing of epidemiological and virological information in responding to zoonotic disease outbreaks. In Indonesia, outbreak response challenges include completeness of data shared between human and animal health authorities. The four-way linking framework (human health laboratory/epidemiology and animal health laboratory/epidemiology) was applied in the investigation of the 193 rd human case of avian influenza A(H5N1) virus infection. As recommended by the framework, outbreak investigation and risk assessment findings were shared. On 18 June 2013, a hospital in West Java Province reported a suspect H5N1 case in a 2-year-old male. The case was laboratory-confirmed that evening, and the information was immediately shared with the Ministry of Agriculture. The human health epidemiology/laboratory team investigated the outbreak and conducted an initial risk assessment on 19 June. The likelihood of secondary cases was deemed low as none of the case contacts were sick. By 3 July, no secondary cases associated with the outbreak were identified. The animal health epidemiology/laboratory investigation was conducted on 19-25 June and found that a live bird market visited by the case was positive for H5N1 virus. Once both human and market virus isolates were sequenced, a second risk assessment was conducted jointly by the human health and animal health epidemiology/laboratory teams. This assessment concluded that the likelihood of additional human cases associated with this outbreak was low but that future sporadic human infections could not be ruled out because of challenges in controlling H5N1 virus contamination in markets. Findings from the outbreak investigation and risk assessments were shared with stakeholders at both Ministries. The four-way linking framework clarified the type of data to be shared. Both human health and animal health teams made ample data available, and there was

  17. ISOLASI DAN IDENTIFIKASI VIRUS AVIAN INFLUENZA SUBTIPE H5N1 DI PETERNAKAN TRADISIONAL KECAMATAN GUNUNGPATI SEMARANG

    Directory of Open Access Journals (Sweden)

    Angga Ari Wibowo

    2012-09-01

    Full Text Available Avian Influenza (AI atau yang lebih dikenal dengan flu burung disebabkan oleh virus influenza yang bermutasi menjadi patogen. Penelitian tentang isolasi dan identifikasi virus AI subtipe H5N1 perlu dilakukan untuk mengetahui keberadaan virus tersebut khususnya di kecamatan Gunungpati. Desain penelitian adalah eks ploratif dengan pengumpulan sampel usap kloaka secara acak di lima kelurahan di kecamatan Gunungpati. Sampel usap kloaka ditumbuhkan pada telur ayam berembrio SPF, kemudian diisolasi RNA-nya dilanjutkan dengan identifikasi subtipe virus AI menggunakan Reverse Transcriptase-Polymerase Chain Reaction (RT–PCR dengan primer pendeteksi gen H5 dan N1. Hasil positif apabila visualisasi hasil elektroforesis dari produk PCR menunjukkan pita-pita spesifik panjang 219 bp untuk H5 dan 131 bp untuk gen N1-nya. Limapuluh sampel usap kloaka yang diisolasi dari lima kelurahan di Gunungpati, delapan isolat positif VAI dan enam diantaranya positif H5N1 dengan angka prevalensi 12%. Isolat positif berasal dari 2 spesies itik (16,67%, 2 dari entok (11,76% dan 2 dari angsa (18,18%. Dari lima kelurahan yang diambil sampelnya, tiga kelurahan ditemukan positif virus H5N1 masing-masing kelurahan Sekaran (6,67%, Kalisegoro (16,67% dan Pakintelan (15,78%. Unggas-unggas air di peternakan unggas tradisional berpotensi sebagai penularan virus AI, khususnya subtipe H5N1.Avian Influenza (AI or better known as bird flu is caused by influenza viruses that mutate into a pathogen. Research on the isolation and the identification of H5N1 subtype needed to be carried out to determine the presence of the virus, particularly in the subdistrict of Gunungpati. The study design was explorative by collecting cloacal swab samples randomly from five villages in Gunungpati. The cloacal swab samples were cultured in embryonated SPF chicken eggs, then the RNA was isolated and followed by the identification of AI virus subtype using Reverse Transcriptase-Polymerase Chain Reaction (RT

  18. TEST KIT FOR THE DETECTION AND GENOTYPING OF HIGHLY PATHOGENIC INFLUENZA VIRUS A H5N1 BY REAL-TIME POLYMERASE CHAIN REACTION

    Directory of Open Access Journals (Sweden)

    S. V. Stepaniuk

    2014-06-01

    Full Text Available Results of the annual monitoring of epizooties indicate that highly pathogenic HPAI/H5N1 avian influenza widely circulated in Eurasian region. Over a period of 2010–2013 years more than 165 cases of outbreaks in 14 countries were found out. Ukraine became one of the first countries in Europe where in Autonomous Republic of Crimea in October 2005 outbreak of avian epizootic with HPAI/H5N1 was documented and until February 2008 more than 236,000 poultry were killed. Since then the question of monitoring of infected both migrating birds and poultry in places of cross contact in Ukraine remains of high priority. The test system is developed for identification and genotyping A H5N1 on three genes (M, H5 and N1 HPAI/H5N1 in real-time mode for polymerase chain reaction. Test kit capacity to detect HPAI/h5n1avian influenza virus and differentiate it from the other viral infection agents of birds and animals were studied by testing of HPAI/H5N1 virus isolated during mass infection outbreak in Crimea in 2005 and cultural specimens of other viral pathogens. It was established that the «DIA Real Avian Influenza» test kit was capable to detect RNA influenza A virus of high pathogenic H5N1 strains having high sensitivity (100% while RNA of the Crimean HPAI/H5N1 isolate studying and specificity (100% while RNA viruses of Newcastle birds disease, fowl powershift, syndrome of drop in egg production and horse influenza studying.

  19. Phylogenetic study-based hemagglutinin (HA) gene of highly pathogenic avian influenza virus (H5N1) detected from backyard chickens in Iran, 2015.

    Science.gov (United States)

    Ghafouri, Syed Ali; Langeroudi, Arash Ghalyanchi; Maghsoudloo, Hossein; Tehrani, Farshad; Khaltabadifarahani, Reza; Abdollahi, Hamed; Fallah, Mohammad Hossein

    2017-02-01

    Highly pathogenic avian influenza (HPAI) viruses of the H5N1 subtype have been diversified into multiple phylogenetic clades over the past decade and are highly genetically variable. In June 2015, one outbreak of HPAI H5N1 in backyard chickens was reported in the Nogardan village of the Mazandaran Province. Tracheal tissues were taken from the dead domestic chickens (n = 10) and processed for RT-PCR. The positive samples (n = 10) were characterized as HPAI H5N1 by sequencing analysis for the hemagglutinin and neuraminidase genes. Phylogenetic analysis of the samples revealed that the viruses belonged to clade 2.3.2.1c, and cluster with the HPAI H5N1 viruses isolated from different avian species in Bulgaria, Romania, and Nigeria in 2015. They were not closely related to other H5N1 isolates detected in previous years in Iran. Our study provides new insights into the evolution and genesis of H5N1 influenza in Iran and has important implications for targeting surveillance efforts to rapidly identify the spread of the virus into and within Iran.

  20. High level of genetic compatibility between swine-origin H1N1 and highly pathogenic avian H5N1 influenza viruses.

    Science.gov (United States)

    Octaviani, Cássio Pontes; Ozawa, Makoto; Yamada, Shinya; Goto, Hideo; Kawaoka, Yoshihiro

    2010-10-01

    Reassortment is an important mechanism for the evolution of influenza viruses. Here, we coinfected cultured cells with the pandemic swine-origin influenza virus (S-OIV) and a contemporary H5N1 virus and found that these two viruses have high genetic compatibility. Studies of human lung cell lines indicated that some reassortants had better growth kinetics than their parental viruses. We conclude that reassortment between these two viruses can occur and could create pandemic H5N1 viruses.

  1. A model to control the epidemic of H5N1 influenza at the source

    Directory of Open Access Journals (Sweden)

    Li KS

    2007-11-01

    Full Text Available Abstract Background No country is fully prepared for a 1918-like pandemic influenza. Averting a pandemic of H5N1 influenza virus depends on the successful control of its endemicity, outbreaks in poultry and occasional spillage into human which carries a case-fatality rate of over 50%. The use of perimetric depopulation and vaccination has failed to halt the spread of the epidemic. Blanket vaccination for all poultry over a large geographical area is difficult. A combination of moratorium, segregation of water fowls from chickens and vaccination have been proved to be effective in the Hong Kong Special Administrative Region (HKSAR since 2002 despite endemicity and outbreaks in neighbouring regions. Systematic surveillance in southern China showed that ducks and geese are the primary reservoirs which transmit the virus to chickens, minor poultry and even migratory birds. Presentation of the hypothesis We hypothesize that this combination of moratorium, poultry segregation and targeted vaccination if successfully adapted to an affected district or province in any geographical region with high endemicity would set an example for the control in other regions. Testing the hypothesis A planned one-off moratorium of 3 weeks at the hottest month of the year should decrease the environmental burden as a source of re-infection. Backyard farms will then be re-populated by hatchlings from virus-free chickens and minor poultry only. Targeted immunization of the ducks and geese present only in the industrial farms and also the chickens would be strictly implemented as blanket immunization of all backyard poultry is almost impossible. Freely grazing ducks and geese would not be allowed until neutralizing antibodies of H5 subtype virus is achieved. As a proof of concept, a simple mathematical model with susceptible-infected-recovered (SIR structure of coupled epidemics between aquatic birds (mainly ducks and geese and chickens was used to estimate

  2. Ferrets develop fatal influenza after inhaling small particle aerosols of highly pathogenic avian influenza virus A/Vietnam/1203/2004 (H5N1

    Directory of Open Access Journals (Sweden)

    Sosna William A

    2010-09-01

    Full Text Available Abstract Background There is limited knowledge about the potential routes for H5N1 influenza virus transmission to and between humans, and it is not clear whether humans can be infected through inhalation of aerosolized H5N1 virus particles. Ferrets are often used as a animal model for humans in influenza pathogenicity and transmissibility studies. In this manuscript, a nose-only bioaerosol inhalation exposure system that was recently developed and validated was used in an inhalation exposure study of aerosolized A/Vietnam/1203/2004 (H5N1 virus in ferrets. The clinical spectrum of influenza resulting from exposure to A/Vietnam/1203/2004 (H5N1 through intranasal verses inhalation routes was analyzed. Results Ferrets were successfully infected through intranasal instillation or through inhalation of small particle aerosols with four different doses of Influenza virus A/Vietnam/1203/2004 (H5N1. The animals developed severe influenza encephalomyelitis following intranasal or inhalation exposure to 101, 102, 103, or 104 infectious virus particles per ferret. Conclusions Aerosolized Influenza virus A/Vietnam/1203/2004 (H5N1 is highly infectious and lethal in ferrets. Clinical signs appeared earlier in animals infected through inhalation of aerosolized virus compared to those infected through intranasal instillation.

  3. Critical control points for avian influenza A H5N1 in live bird markets in low resource settings.

    Science.gov (United States)

    Samaan, Gina; Gultom, Anita; Indriani, Risa; Lokuge, Kamalini; Kelly, Paul M

    2011-06-01

    Live bird markets can become contaminated with and become a source of transmission for avian influenza viruses including the highly pathogenic H5N1 strain. Many countries affected by the H5N1-virus have limited resources for programs in environmental health, sanitation and disease control in live bird markets. This study proposes five critical control points (CCPs) to reduce the risk of H5N1-virus contamination in markets in low resource settings. The CCPs were developed based on three surveys conducted in Indonesia: a cross-sectional survey in 119 markets, a knowledge, attitudes and practice survey in 3 markets and a microbiological survey in 83 markets. These surveys assessed poultry workflow, market infrastructure, hygiene and regulatory practices and microbiological contamination with the H5N1-virus. The five CCPs identified were (1) reducing risk of receiving infected birds into the market, (2) reducing the risk of virus spread between different bird flocks in holding cages, (3) reducing surface contamination by isolating slaughter processes from other poultry-related processes, (4) minimizing the potential for contamination during evisceration of carcasses and (5) reducing the risk of surface contamination in the sale zone of the market. To be relevant for low resource settings, the CCPs do not necessitate large infrastructure changes. The CCPs are suited for markets that slaughter poultry and have capacity for daily disposal and removal of solid waste from the market. However, it is envisaged that the CCPs can be adapted for the development of risk-based programs in various settings.

  4. Genetic and antigenic analysis of H5N1 viruses for selection of HA-donor virus for vaccine strains.

    Science.gov (United States)

    Bhatia, S; Kunal, A; Khandia, R; Siddiqui, A; Pateriya, A K; Sood, R

    2013-12-01

    Genetic and antigenic analysis of H5N1 viruses, isolated in India during a period from year 2006 to 2010, was carried out for selection of the potential H5-HA (haemagglutinin) gene donor virus for developing a reverse genetics based DIVA marker H5 vaccine for poultry in India. Out of the 47 H5N1 viruses (clade 2.2), 14 representative viruses were selected on the basis of amino acid sequence analysis of HA1 gene for further antigenic characterization. Using antigenic cartography, an antigenic map was constructed based on the data of cross-HI (haemagglutinin inhibition) titration of 14 sera versus 14 viruses to visualize the relatedness among the antigens and antigenic coverage of the sera. Sera against five H5N1 viruses (A/crow/Assam/142119/2008, A/chicken/West Bengal/100879/2008, A/chicken/West Bengal/155505/2009, A/chicken/West Bengal/80995/2008 and A/chicken/West Bengal/81760/2008) exhibited maximum (100 %) antigenic coverage, hence, were selected as the potential HA donor viruses. However, the virus strain A/chicken/West Bengal/80995/2008 matched completely with the consensus amino acid sequence of the 47 viruses, therefore, was considered the best HA donor candidate out of the five showing 100 % antigenic coverage. The present study demonstrates a stepwise methodology for logical selection of vaccine strain or HA gene donor strain for developing H5 vaccines using genetic and antigenic data.

  5. Non Coding Region dan Amino Terminus Gen Polimerase Asidik Virus Avian Influenza Subtipe H5N1 Asal Hewan Indonesia

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    Gusti Ayu Yuniati Kencana

    2010-09-01

    Full Text Available The knowledge on the species adaptation factor of avian influenza virus of H5N1 subtype (AIV H5N1is very important as a signal for the emergence of a new strain with pandemic potential. This research wasconducted to find out the sequence variation of the Non-Coding Region (NCR and Coding Region (CR of 5’-terminal cRNA of the polymerase acidic (PA. Total RNA from twenty six (26 avian influenza virussubtype H5N1 isolates were amplified using reverse-transcriptase-polymerase chain reaction (RT-PCRwith a universal forward primer for influenza virus and specifically designed backward primers. Nineteen(19 gene fragments of PA could be amplified. RT-PCR products were sequenced and analyzed using Mega4 software. The length of NCR of PA gene was found to be 24 bases and conserved. A/T composition of PANCR was 58.3%. Species and geographical specificity could not be found in the genetic distance, the aminoacid polymorphism, as well as the phylogenetic analysis of the CR. RNA sequencing is discussed andrecomended to be studied further.

  6. A review of ireland's waterbirds, with emphasis on wintering migrants and reference to H5N1 avian influenza

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    Crowe O

    2009-12-01

    Full Text Available Abstract Ireland is characterised by its diversity and large abundance of wetlands, making it attractive to a wide variety of waterbirds throughout the year. This paper presents an overview of Ireland's waterbirds, including ecological factors relevant to the potential introduction, maintenance, transmission and spread of infectious agents, including the H5N1 avian influenza virus, in Ireland. Particular emphasis is placed on five groups of wintering migrants (dabbling and sieving wildfowl, grazing wildfowl, diving wildfowl, waders and gulls, noting that the H5N1 avian influenza virus has mainly been isolated from this subset of waterbirds. Ireland's wetlands are visited during the spring and summer months by hundreds of thousands of waterbirds which come to breed, predominantly from southern latitudes, and during the autumn and winter by waterbirds which come from a variety of origins (predominantly northern latitudes, and which are widely distributed and often congregate in mixed-species flocks. The distribution, feeding habits and social interactions of the five groups of wintering migrants are considered in detail. Throughout Ireland, there is interaction between different waterbird populations (breeding migrants, the wintering migrants and resident waterbird populations. There is also a regular and complex pattern of movement between feeding and roosting areas, and between wetlands and farmland. These interactions are likely to facilitate the rapid transmission and spread of the H5N1 avian influenza virus, if it were present in Ireland.

  7. H5N1 Avian Influenza Pre-pandemic Vaccine Strains in China

    Institute of Scientific and Technical Information of China (English)

    BO Hong; DONG Li Bo; ZHANG Ye; DONG Jie; ZOU Shu Mei; GAO Rong Bao; WANG Da Yan; SHU Yue Long

    2014-01-01

    ObjectiveTo prepare the 4 candidate vaccine strains of H5N1 avian influenza virus isolated in China. MethodsRecombinant viruses were rescued using reverse genetics. Neuraminidase (NA) and hemagglutinin (HA) segments of the A/Xinjiang/1/2006, A/Guangxi/1/2009, A/Hubei/1/2010, and A/Guangdong/1/2011 viruses were amplified by RT-PCR. Multibasic amino acid cleavage site of HA was removed and ligated into the pCIpolI vector for virus rescue. The recombinant viruses were evaluated by trypsin dependent assays. Their embryonate survival and antigenicity were compared with those of the respective wild-type viruses. ResultsThe 4 recombinant viruses showed similar antigenicity compared with wild-type viruses, chickenembryo survival and trypsin-dependent characteristics. ConclusionThe 4 recombinantviruses rescued using reverse genetics meet the criteria for classification of low pathogenic avian influenza strains, thus supporting the use of them for the development of seeds and production of pre-pandemic vaccines.

  8. Neurovirulence of H5N1 infection in ferrets is mediated by multifocal replication in distinct permissive neuronal cell regions.

    Directory of Open Access Journals (Sweden)

    Jennifer R Plourde

    Full Text Available Highly pathogenic avian influenza A (HPAI, subtype H5N1, remains an emergent threat to the human population. While respiratory disease is a hallmark of influenza infection, H5N1 has a high incidence of neurological sequelae in many animal species and sporadically in humans. We elucidate the temporal/spatial infection of H5N1 in the brain of ferrets following a low dose, intranasal infection of two HPAI strains of varying neurovirulence and lethality. A/Vietnam/1203/2004 (VN1203 induced mortality in 100% of infected ferrets while A/Hong Kong/483/1997 (HK483 induced lethality in only 20% of ferrets, with death occurring significantly later following infection. Neurological signs were prominent in VN1203 infection, but not HK483, with seizures observed three days post challenge and torticollis or paresis at later time points. VN1203 and HK483 replication kinetics were similar in primary differentiated ferret nasal turbinate cells, and similar viral titers were measured in the nasal turbinates of infected ferrets. Pulmonary viral titers were not different between strains and pathological findings in the lungs were similar in severity. VN1203 replicated to high titers in the olfactory bulb, cerebral cortex, and brain stem; whereas HK483 was not recovered in these tissues. VN1203 was identified adjacent to and within the olfactory nerve tract, and multifocal infection was observed throughout the frontal cortex and cerebrum. VN1203 was also detected throughout the cerebellum, specifically in Purkinje cells and regions that coordinate voluntary movements. These findings suggest the increased lethality of VN1203 in ferrets is due to increased replication in brain regions important in higher order function and explains the neurological signs observed during H5N1 neurovirulence.

  9. Two glycosylation sites in H5N1 influenza virus hemagglutinin that affect binding preference by computer-based analysis.

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    Wentian Chen

    Full Text Available Increasing numbers of H5N1 influenza viruses (IVs are responsible for human deaths, especially in North Africa and Southeast Asian. The binding of hemagglutinin (HA on the viral surface to host sialic acid (SA receptors is a requisite step in the infection process. Phylogenetic analysis reveals that H5N1 viruses can be divided into 10 clades based on their HA sequences, with most human IVs centered from clade 1 and clade 2.1 to clade 2.3. Protein sequence alignment in various clades indicates the high conservation in the receptor-binding domains (RBDs is essential for binding with the SA receptor. Two glycosylation sites, 158N and 169N, also participate in receptor recognition. In the present work, we attempted to construct a serial H5N1 HA models including diverse glycosylated HAs to simulate the binding process with various SA receptors in silico. As the SA-α-2,3-Gal and SA-α-2,6-Gal receptor adopted two distinctive topologies, straight and fishhook-like, respectively, the presence of N-glycans at 158N would decrease the affinity of HA for all of the receptors, particularly SA-α-2,6-Gal analogs. The steric clashes of the huge glycans shown at another glycosylation site, 169N, located on an adjacent HA monomer, would be more effective in preventing the binding of SA-α-2,3-Gal analogs.

  10. Retrospective space-time analysis of H5N1 Avian Influenza emergence in Thailand

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    Shanmugasundaram Jothiganesh

    2010-01-01

    Full Text Available Abstract Background The highly pathogenic avian influenza (HPAI H5N1 virus remains a worldwide threat to human and animal health, while the mechanisms explaining its epizootic emergence and re-emergence in poultry are largely unknown. Data from Thailand, a country that experienced significant epidemics in poultry and has recorded suspicious cases of HPAI on a daily basis since 2004, are used here to study the process of emergence. A spatial approach is employed to describe all HPAI H5N1 virus epizootics from 2004 to 2008 and to characterize the pattern of emergence: multiple independent introductions of the virus followed by moderate local spread vs. very rare emergences followed by strong local spread and rare long range diffusion jumps. Sites where epizootics originate (by foreign introduction, local persistence, or long range jump were selected from those to which the disease subsequently spreads using a filter based on relative date and position. The spatial distribution of these selected foci was statistically analyzed, and to differentiate environmental factors from long range diffusion, we investigate the relationship of these foci with environmental exposure factors and with rearing characteristics. Results During each wave of epizootics, the temporal occurrence of cases did not show a temporal interruption of more than a week. All foci were globally clustered; i.e., more than 90% of cases had a previous case within a 10 km range and a 21 day period of time, showing a strong local spread. We were able to estimate 60 km as the maximum distance for the local farm to farm dissemination process. The remaining "emergent" cases have occurred randomly over Thailand and did not show specific location, clusters, or trends. We found that these foci are not statistically related to specific environmental conditions or land cover characteristics, and most of them may be interpreted as long range diffusion jumps due to commercial practices

  11. 长沙市家禽市场环境中H5N1亚型禽流感病毒传播风险研究%Risk related to the transmission of H5N1 subtype avian influenza virus in the environment of poultry markets in Changsha, China

    Institute of Scientific and Technical Information of China (English)

    张如胜; 欧新华; 宋克云; 袁洁; 陈田木; 肖姗; 孙边成

    2012-01-01

    .7%,19/77).H5 subtype AIV positive rate was different in the tested specimens,with ranking of positive rates were sewage (50.0%,24/48),feathers (44.5%,4/9 ),birds stools ( 29.8%,14/47) and smearing samples of poultry cages (14.3%,8/56),with statistically significant differences (P<0.01).Four H5N1 HA genes TA cloning were successfully constructed and identified as Eurasian branch,similar to viruses isolated in mainland China and Hong Kong in the same group,according to genetic analysis.Sequence data of the four HA genes showed the same feature of high pathogenicity,compared to the H5N 1 AIV from mainland China of human origin.The receptor specificities were still with avian influenza origin (QSG)and the connecting peptide between HA1 and HA2 possessing the polybasic motif (RERRRKK or RERRGKK).Conclusion One of the reasons for H5N1 antibody positive rate of 25.5% among poultry markets workers was that there were large numbers of H5N 1 subtype AIV detected in the environment of poultry markets and HA genes of H5N 1 subtype AIV in the poultry markets environment carried molecular characteristics of highly pathogenic which could increase the risk for H5N1 subtype AIV transmission in the environment of poultry markets.%目的 对长沙市家禽市场职业暴露人群进行禽流感病毒(AIV)H5N1亚型抗体水平和环境AIV核酸检测,并对环境中AIV H5N1亚型的血凝素(HA)基因进行测序分析.方法 抽取长沙市1个区和1个县,各选择2个城区或乡镇家禽市场进行职业暴露人群H5N1抗体和环境AIV核酸检测.利用单放射免疫扩散溶血实验(SRH)对102份家禽市场职业暴露人员血清标本进行H5N1抗体检测,real-time PCR方法检测160份家禽市场环境标本(污水、禽类粪便、羽毛和禽类笼具表面涂抹标本)AIV核酸,对4份污水H5N1亚型AIV核酸阳性标本进行HA基因RT-PCR扩增和TA克隆测序,测序结果利用Lasergene和Mega 5.0软件进行氨基酸比对

  12. The new temperature-sensitive mutation PA-F35S for developing recombinant avian live attenuated H5N1 influenza vaccine

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    Zhang Wenting

    2012-05-01

    Full Text Available Abstract Background H5N1 highly pathogenic avian influenza virus (HPAIV is continuously circulating in many Asian countries and threatening poultry industry and human population. Vaccination is the best strategy to control H5N1 HPAIV infection in poultry and transmission to human population. The aim of this study is to identify new temperature-sensitive (ts mutations for developing recombinant avian live attenuated H5N1 influenza vaccine. Findings A “6 + 2” recombinant virus C4/W1 that contained NA gene and modified HA gene from virus A/chicken/Hubei/327/2004 (H5N1 (C4, and six internal genes from virus A/duck/Hubei/W1/2004 (H9N2 (W1 was generated using reverse genetics and subsequently passaged in chicken eggs at progressively lower temperatures (32°C, 28°C and 25°C. The resulting virus acquired ts phenotype and one of its amino acid mutations, PA (F35S, was identified as ts mutation. Furthermore, when used as live attenuated vaccine, the recombinant virus with this ts mutation PA (F35S provided efficient protection for chickens against H5N1 HPAIV infection. Conclusions These findings highlight the potential of the new ts mutation PA (F35S in developing recombinant avian live attenuated H5N1 influenza vaccine.

  13. Specific polyclonal F(ab')2 neutralize a large panel of highly pathogenic avian influenza A viruses (H5N1) and control infection in mice.

    Science.gov (United States)

    Herbreteau, Cécile Hélène; Jacquot, Frédéric; Rith, Sareth; Vacher, Laurent; Nguyen, Ludovic; Carbonnelle, Caroline; Lotteau, Vincent; Jolivet, Michel; Raoul, Hervé; Buchy, Philippe; Saluzzo, Jean-François

    2014-01-01

    There is still no specific therapy for infection with the highly pathogenic avian influenza A virus (HPAI) H5N1, which caused 39 human cases with a 64% fatality rate in 2013. We prepared highly purified specific equine polyclonal immunoglobulin fragments (F(ab')2) against H5N1 and tested them for efficacy in vitro and with different administration schedules in H5N1-challenged BALB/c mice. in vitro, F(ab')2 neutralized 21 different H5N1 strains from different areas, representative of 11 different clades and sub-clades and 9 years of evolution of the virus. In vivo mouse experiments identified that the most efficient administration protocol consists of five consecutive daily injections after infection; 10 mg/kg giving a 60% increase in survival. These data demonstrate the ability of anti-H5N1 F(ab')2 to markedly reduce the mortality and morbidity associated with infection of mice with HPAI H5N1 virus, and their potential for human therapy.

  14. Estimation of transmission parameters of H5N1 avian influenza virus in chickens.

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    Annemarie Bouma

    2009-01-01

    Full Text Available Despite considerable research efforts, little is yet known about key epidemiological parameters of H5N1 highly pathogenic influenza viruses in their avian hosts. Here we show how these parameters can be estimated using a limited number of birds in experimental transmission studies. Our quantitative estimates, based on Bayesian methods of inference, reveal that (i the period of latency of H5N1 influenza virus in unvaccinated chickens is short (mean: 0.24 days; 95% credible interval: 0.099-0.48 days; (ii the infectious period of H5N1 virus in unvaccinated chickens is approximately 2 days (mean: 2.1 days; 95%CI: 1.8-2.3 days; (iii the reproduction number of H5N1 virus in unvaccinated chickens need not be high (mean: 1.6; 95%CI: 0.90-2.5, although the virus is expected to spread rapidly because it has a short generation interval in unvaccinated chickens (mean: 1.3 days; 95%CI: 1.0-1.5 days; and (iv vaccination with genetically and antigenically distant H5N2 vaccines can effectively halt transmission. Simulations based on the estimated parameters indicate that herd immunity may be obtained if at least 80% of chickens in a flock are vaccinated. We discuss the implications for the control of H5N1 avian influenza virus in areas where it is endemic.

  15. Characterization of the influenza A H5N1 viruses of the 2008-09 outbreaks in India reveals a third introduction and possible endemicity.

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    Alok K Chakrabarti

    Full Text Available Widespread infection of highly pathogenic avian influenza A H5N1 was reported from backyard and commercial poultry in West Bengal (WB, an eastern state of India in early 2008. Infection gradually spread to Tripura, Assam and Sikkim, the northeastern states, with 70 outbreaks reported between January 2008 and May 2009. Whole genome sequence analysis of three isolates from WB, one isolate from Tripura along with the analysis of hemagglutinin (HA and neuraminidase (NA genes of 17 other isolates was performed during this study. In the HA gene phylogenetic tree, all the 2008-09 Indian isolates belonged to EMA3 sublineage of clade 2.2. The closest phylogenetic relationship was found to be with the 2007-09 isolates from Bangladesh and not with the earlier 2006 and 2007 Indian isolates implying a third introduction into the country. The receptor-binding pocket of HA1 of two isolates from WB showed S221P mutation, one of the markers predicted to be associated with human receptor specificity. Two substitutions E119A (2 isolates of WB and N294S (2 other isolates of WB known to confer resistance to NA inhibitors were observed in the active site of neuraminidase. Several additional mutations were observed within the 2008-09 Indian isolates indicating genetic diversification. Overall, the study is indicative of a possible endemicity in the eastern and northeastern parts of the country, demanding active surveillance specifically in view of the critical mutations that have been observed in the influenza A H5N1 viruses.

  16. Different environmental drivers of highly pathogenic avian influenza H5N1 outbreaks in poultry and wild birds.

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    Si, Yali; de Boer, Willem F; Gong, Peng

    2013-01-01

    A large number of highly pathogenic avian influenza (HPAI) H5N1 outbreaks in poultry and wild birds have been reported in Europe since 2005. Distinct spatial patterns in poultry and wild birds suggest that different environmental drivers and potentially different spread mechanisms are operating. However, previous studies found no difference between these two outbreak types when only the effect of physical environmental factors was analysed. The influence of physical and anthropogenic environmental variables and interactions between the two has only been investigated for wild bird outbreaks. We therefore tested the effect of these environmental factors on HPAI H5N1 outbreaks in poultry, and the potential spread mechanism, and discussed how these differ from those observed in wild birds. Logistic regression analyses were used to quantify the relationship between HPAI H5N1 outbreaks in poultry and environmental factors. Poultry outbreaks increased with an increasing human population density combined with close proximity to lakes or wetlands, increased temperatures and reduced precipitation during the cold season. A risk map was generated based on the identified key factors. In wild birds, outbreaks were strongly associated with an increased Normalized Difference Vegetation Index (NDVI) and lower elevation, though they were similarly affected by climatic conditions as poultry outbreaks. This is the first study that analyses the differences in environmental drivers and spread mechanisms between poultry and wild bird outbreaks. Outbreaks in poultry mostly occurred in areas where the location of farms or trade areas overlapped with habitats for wild birds, whereas outbreaks in wild birds were mainly found in areas where food and shelters are available. The different environmental drivers suggest that different spread mechanisms might be involved: HPAI H5N1 spread to poultry via both poultry and wild birds, whereas contact with wild birds alone seems to drive the outbreaks

  17. Indium-tin-oxide thin film transistor biosensors for label-free detection of avian influenza virus H5N1.

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    Guo, Di; Zhuo, Ming; Zhang, Xiaoai; Xu, Cheng; Jiang, Jie; Gao, Fu; Wan, Qing; Li, Qiuhong; Wang, Taihong

    2013-04-22

    As continuous outbreak of avian influenza (AI) has become a threat to human health, economic development and social stability, it is urgently necessary to detect the highly pathogenic avian influenza H5N1 virus quickly. In this study, we fabricated indium-tin-oxide thin-film transistors (ITO TFTs) on a glass substrate for the detecting of AI H5N1. The ITO TFT is fabricated by a one-shadow-mask process in which a channel layer can be simultaneously self-assembled between ITO source/drain electrodes during magnetron sputtering deposition. Monoclonal anti-H5N1 antibodies specific for AI H5N1 virus were covalently immobilized on the ITO channel by (3-glycidoxypropyl)trimethoxysilane. The introduction of target AI H5N1 virus affected the electronic properties of the ITO TFT, which caused a change in the resultant threshold voltage (VT) and field-effect mobility. The changes of ID-VG curves were consistent with an n-type field effect transistor behavior affected by nearby negatively charged AI H5N1 viruses. The transistor based sensor demonstrated high selectivity and stability for AI H5N1 virus sensing. The sensor showed linear response to AI H5N1 in the concentrations range from 5×10(-9) g mL(-1) to 5×10(-6) g mL(-1) with a detection limit of 0.8×10(-10) g mL(-1). Moreover, the ITO TFT biosensors can be repeatedly used through the washing processes. With its excellent electric properties and the potential for mass commercial production, ITO TFTs can be promising candidates for the development of label-free biosensors.

  18. Development of a dual-protective live attenuated vaccine against H5N1 and H9N2 avian influenza viruses by modifying the NS1 gene.

    Science.gov (United States)

    Choi, Eun-hye; Song, Min-Suk; Park, Su-Jin; Pascua, Philippe Noriel Q; Baek, Yun Hee; Kwon, Hyeok-il; Kim, Eun-Ha; Kim, Semi; Jang, Hyung-Kwan; Poo, Haryoung; Kim, Chul-Joong; Choi, Young Ki

    2015-07-01

    An increasing number of outbreaks of avian influenza H5N1 and H9N2 viruses in poultry have caused serious economic losses and raised concerns for human health due to the risk of zoonotic transmission. However, licensed H5N1 and H9N2 vaccines for animals and humans have not been developed. Thus, to develop a dual H5N1 and H9N2 live-attenuated influenza vaccine (LAIV), the HA and NA genes from a virulent mouse-adapted avian H5N2 (A/WB/Korea/ma81/06) virus and a recently isolated chicken H9N2 (A/CK/Korea/116/06) virus, respectively, were introduced into the A/Puerto Rico/8/34 backbone expressing truncated NS1 proteins (NS1-73, NS1-86, NS1-101, NS1-122) but still possessing a full-length NS gene. Two H5N2/NS1-LAIV viruses (H5N2/NS1-86 and H5N2/NS1-101) were highly attenuated compared with the full-length and remaining H5N2/NS-LAIV viruses in a mouse model. Furthermore, viruses containing NS1 modifications were found to induce more IFN-β activation than viruses with full-length NS1 proteins and were correspondingly attenuated in mice. Intranasal vaccination with a single dose (10(4.0) PFU/ml) of these viruses completely protected mice from a lethal challenge with the homologous A/WB/Korea/ma81/06 (H5N2), heterologous highly pathogenic A/EM/Korea/W149/06 (H5N1), and heterosubtypic highly virulent mouse-adapted H9N2 viruses. This study clearly demonstrates that the modified H5N2/NS1-LAIV viruses attenuated through the introduction of mutations in the NS1 coding region display characteristics that are desirable for live attenuated vaccines and hold potential as vaccine candidates for mammalian hosts.

  19. Spatio-temporal epidemiology of highly pathogenic avian influenza (subtype H5N1) in poultry in eastern India.

    Science.gov (United States)

    Dhingra, Madhur S; Dissanayake, Ravi; Negi, Ajender Bhagat; Oberoi, Mohinder; Castellan, David; Thrusfield, Michael; Linard, Catherine; Gilbert, Marius

    2014-10-01

    In India, majority outbreaks of highly pathogenic avian influenza (HPAI) H5N1 have occurred in eastern states of West Bengal, Assam and Tripura. This study aimed to identify disease clusters and risk factors of HPAI H5N1 in these states, for targeted surveillance and disease control. A spatial scan statistic identified two significant disease clusters in West Bengal and Assam, occurring during January and November-December 2008, respectively. Key risk factors were identified at sub-district level using bootstrapped logistic regression and boosted regression trees model. With both methods, HPAI H5N1 outbreaks in backyard poultry were associated with accessibility in terms of time taken to access a city with >50,000 persons, human population density and duck density (P<0.005). In addition, areas at lower elevation were also identified as high risk by BRT model. It is recommended that risk-based surveillance should be implemented in high duck density areas and all live-bird markets in high-throughput locations.

  20. Modeling and roles of meteorological factors in outbreaks of highly pathogenic avian influenza H5N1.

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    Paritosh K Biswas

    Full Text Available The highly pathogenic avian influenza A virus subtype H5N1 (HPAI H5N1 is a deadly zoonotic pathogen. Its persistence in poultry in several countries is a potential threat: a mutant or genetically reassorted progenitor might cause a human pandemic. Its world-wide eradication from poultry is important to protect public health. The global trend of outbreaks of influenza attributable to HPAI H5N1 shows a clear seasonality. Meteorological factors might be associated with such trend but have not been studied. For the first time, we analyze the role of meteorological factors in the occurrences of HPAI outbreaks in Bangladesh. We employed autoregressive integrated moving average (ARIMA and multiplicative seasonal autoregressive integrated moving average (SARIMA to assess the roles of different meteorological factors in outbreaks of HPAI. Outbreaks were modeled best when multiplicative seasonality was incorporated. Incorporation of any meteorological variable(s as inputs did not improve the performance of any multivariable models, but relative humidity (RH was a significant covariate in several ARIMA and SARIMA models with different autoregressive and moving average orders. The variable cloud cover was also a significant covariate in two SARIMA models, but air temperature along with RH might be a predictor when moving average (MA order at lag 1 month is considered.

  1. Southward autumn migration of waterfowl facilitates cross-continental transmission of the highly pathogenic avian influenza H5N1 virus

    Science.gov (United States)

    Xu, Yanjie; Gong, Peng; Wielstra, Ben; Si, Yali

    2016-08-01

    The highly pathogenic avian influenza subtype H5N1 (HPAI H5N1) is a worldwide zoonotic infectious disease, threatening humans, poultry and wild birds. The role of wild birds in the spread of HPAI H5N1 has previously been investigated by comparing disease spread patterns with bird migration routes. However, the different roles that the southward autumn and northward spring migration might play in virus transmission have hardly been explored. Using direction analysis, we analyze HPAI H5N1 transmission directions and angular concentration of currently circulating viral clades, and compare these with waterfowl seasonal migration directions along major waterfowl flyways. Out of 22 HPAI H5N1 transmission directions, 18 had both a southward direction and a relatively high concentration. Differences between disease transmission and waterfowl migration directions were significantly smaller for autumn than for spring migration. The four northward transmission directions were found along Asian flyways, where the initial epicenter of the virus was located. We suggest waterfowl first picked up the virus from East Asia, then brought it to the north via spring migration, and then spread it to other parts of world mainly by autumn migration. We emphasize waterfowl autumn migration plays a relatively important role in HPAI H5N1 transmission compared to spring migration.

  2. PEMBUATAN DAN STANDARISASI ANTIGEN AI H5N1 KOMERSIAL UNTUK MONITORING TITER ANTIBODI HASIL VAKSINASI AI DI INDUSTRI PETERNAKAN AYAM

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    Retno D. Soejoedono

    2012-04-01

    Full Text Available Vaccination is one of the chosen strategy for controling AI H5N1 in Indonesia. Vaccination able to induce protective antibodies against AI but unable to inhibit viral infection. Determination of antibody titers in the serum from bird vaccinated with AI-H5N1 vaccine consisting of 2 or 3 different AI virus isolates difficult to be meassured if the antigen for HI test is uncalibrated yet. Furthermore, the determination of a minimum protective antibody titer against the challenge of AI virus circulating in the field at this time needs to be done. This study aims to determine the H5N1 AI virus antigen for standart HI test and the minimum titre of antibodies that able neutralize virus infection. As much as 55 chickens were divided into 11 groups, 10 groups vaccinated with commercial AI vaccine and AI H5N1 field isolat antigen. Four types of commercial vaccines were veccinated to one group and seven other groups vaccinated with the antigen AI Legok 2004, Nagrak Ag 2009, Ag Lawang 2010, as well as polyvalent Ag combination of these three types of antigen. After third vaccinations, the presence of antibodieswere meassured by HI test. Serum with a titer test 26-28 were tested for the capability of virus neutralizationin using virus neutralization test against three different H5N1 AI virus field isolates. The test results showed that the H5N1 subtype AI virus antigen representative as standart antigen for HI test is antigen Legok 2004 and the minimum titer which able neutralize H5N1 AI virus field isolates 28

  3. Characterization of low-pathogenicity H5N1 avian influenza viruses from North America

    Science.gov (United States)

    Spackman, Erica; Swayne, David E.; Suarez, David L.; Senne, Dennis A.; Pedersen, Janice C.; Killian, Mary Lea; Pasick, John; Handel, Katherine; Somanathan Pillai, Smitha; Lee, Chang-Won; Stallknecht, David; Slemons, Richard; Ip, Hon S.; Deliberto, Tom

    2007-01-01

    Wild-bird surveillance in North America for avian influenza (AI) viruses with a goal of early identification of the Asian H5N1 highly pathogenic AI virus has identified at least six low-pathogenicity H5N1 AI viruses between 2004 and 2006. The hemagglutinin (HA) and neuraminidase (NA) genes from all 6 H5N1 viruses and an additional 38 North American wild-bird-origin H5 subtype and 28 N1 subtype viruses were sequenced and compared with sequences available in GenBank by phylogenetic analysis. Both HA and NA were phylogenetically distinct from those for viruses from outside of North America and from those for viruses recovered from mammals. Four of the H5N1 AI viruses were characterized as low pathogenicity by standard in vivo pathotyping tests. One of the H5N1 viruses, A/MuteSwan/MI/451072-2/06, was shown to replicate to low titers in chickens, turkeys, and ducks. However, transmission of A/MuteSwan/MI/451072-2/06 was more efficient among ducks than among chickens or turkeys based on virus shed. The 50% chicken infectious dose for A/MuteSwan/MI/451072-2/06 and three other wild-waterfowl-origin H5 viruses were also determined and were between 105.3 and 107.5 50% egg infective doses. Finally, seven H5 viruses representing different phylogenetic clades were evaluated for their antigenic relatedness by hemagglutination inhibition assay, showing that the antigenic relatedness was largely associated with geographic origin. Overall, the data support the conclusion that North American H5 wild-bird-origin AI viruses are low-pathogenicity wild-bird-adapted viruses and are antigenically and genetically distinct from the highly pathogenic Asian H5N1 virus lineage.

  4. Characterization of low-pathogenicity H5N1 avian influenza viruses from North America

    Science.gov (United States)

    Spackman, Erica; Swayne, D. E.; Suarez, D. L.; Senne, D. A.; Pedersen, J. C.; Killian, M. L.; Pasick, J.; Handel, K.; Pillai, S. P. S.; Lee, C. -W.; Stallknecht, D.; Slemons, R.; Ip, H. S.; Deliberto, T.

    2007-01-01

    Wild-bird surveillance in North America for avian influenza (AI) viruses with a goal of early identification of the Asian H5N1 highly pathogenic AI virus has identified at least six low-pathogenicity H5N1 AI viruses between 2004 and 2006. The hemagglutinin (HA) and neuraminidase (NA) genes from all 6 H5N1 viruses and an additional 38 North American wild-bird-origin H5 subtype and 28 N1 subtype viruses were sequenced and compared with sequences available in GenBank by phylogenetic analysis. Both HA and NA were phylogenetically distinct from those for viruses from outside of North America and from those for viruses recovered from mammals. Four of the H5N1 AI viruses were characterized as low pathogenicity by standard in vivo pathotyping tests. One of the H5N1 viruses, A/MuteSwan/MI/451072-2/06, was shown to replicate to low titers in chickens, turkeys, and ducks. However, transmission of A/MuteSwan/MI/451072-2/06 was more efficient among ducks than among chickens or turkeys based on virus shed. The 50% chicken infectious dose for A/MuteSwan/MI/451072-2/06 and three other wild-waterfowl-origin H5 viruses were also determined and were between 10 5.3 and 107.5 50% egg infective doses. Finally, seven H5 viruses representing different phylogenetic clades were evaluated for their antigenic relatedness by hemagglutination inhibition assay, showing that the antigenic relatedness was largely associated with geographic origin. Overall, the data support the conclusion that North American H5 wild-bird-origin AI viruses are low-pathogenicity wild-bird-adapted viruses and are antigenically and genetically distinct from the highly pathogenic Asian H5N1 virus lineage. Copyright ?? 2007, American Society for Microbiology. All Rights Reserved.

  5. [A(H5N1) and A(H7N9) avian influenza: the H7N9 avian influenza outbreak of 2013].

    Science.gov (United States)

    Wang, Quan; Yao, Kai-Hu

    2013-06-01

    influenza virus can infect humans and cause disease. The clinical presentation of human infection is usually mild, but the infection caused by A(H5N1) avian influenza virus occurring initially in Hongkong in 1997 or the A(H7N9) virus isolated first at the beginning of this year in China is severe and characterized by high mortality. The mortality rate of adolescents and children caused by H5N1 avian influenza is lower than that of adults and the younger the child the lower the mortality rate. A few pediatric H7N9 avian influenza cases recovered soon after treatment. A child was determined to be a H7N9 avian influenza virus carrier. These findings suggested that the pediatric H7N9 avian influenza infection was mild. It is very important to start anti-virus treatment with oseltamivir as early as possible in cases of avian influenza infection is considered. Combined therapy, including respiratory and circulatory support and inhibiting immunological reaction, is emphasized in the treatment of severe cases.

  6. Plant-based rapid production of recombinant subunit hemagglutinin vaccines targeting H1N1 and H5N1 influenza.

    Science.gov (United States)

    Shoji, Yoko; Chichester, Jessica A; Jones, Mark; Manceva, Slobodanka D; Damon, Emily; Mett, Vadim; Musiychuk, Konstantin; Bi, Hong; Farrance, Christine; Shamloul, Moneim; Kushnir, Natasha; Sharma, Satish; Yusibov, Vidadi

    2011-01-01

    In 2009, a novel H1N1 swine influenza virus was isolated from infected humans in Mexico and the United States, and rapidly spread around the world. Another virus, a highly pathogenic avian influenza virus of the H5N1 subtype, identified by the World Health Organization as a potential pandemic threat in 1997, continues to be a significant risk. While vaccination is the preferred strategy for the prevention and control of influenza infections, the traditional egg-based approach to producing influenza vaccines does not provide sufficient capacity and adequate speed to satisfy global needs to combat newly emerging strains, seasonal or potentially pandemic. Significant efforts are underway to develop and implement new cell substrates with improved efficiency for influenza vaccine development and manufacturing. In recent years, plants have been used to produce recombinant proteins including subunit vaccines and antibodies. The main advantages of using plant systems for the production of vaccine antigens against influenza are their independence from pathogenic viruses, and cost and time efficiency. Here, we describe the large-scale production of recombinant hemagglutinin proteins from A/California/04/09 (H1N1) and A/Indonesia/05/05 (H5N1) strains of influenza virus in Nicotiana benthamiana plants, and their immunogenicity (serum hemagglutination inhibition and virus neutralizing antibodies), and safety in animal models. These results support the testing of these candidate vaccines in human volunteers and also the utility of our plant expression system for large-scale recombinant influenza vaccine production.

  7. Vaccination with virus-like particles containing H5 antigens from three H5N1 clades protects chickens from H5N1 and H5N8 influenza viruses.

    Science.gov (United States)

    Kapczynski, Darrell R; Tumpey, Terrence M; Hidajat, Rachmat; Zsak, Aniko; Chrzastek, Klaudia; Tretyakova, Irina; Pushko, Peter

    2016-03-18

    Highly pathogenic avian influenza (HPAI) viruses, especially H5N1 strains, represent a public health threat and cause widespread morbidity and mortality in domestic poultry. Recombinant virus-like particles (VLPs) represent a promising novel vaccine approach to control avian influenza including HPAI strains. Influenza VLPs contain viral hemagglutinin (HA), which can be expressed in cell culture within highly immunogenic VLPs that morphologically and antigenically resemble influenza virions, except VLPs are non-infectious. Here we describe a recombinant VLP containing HA proteins derived from three distinct clades of H5N1 viruses as an experimental, broadly protective H5 avian influenza vaccine. A baculovirus vector was configured to co-express the H5 genes from recent H5N1 HPAI isolates A/chicken/Germany/2014 (clade 2.3.4.4), A/chicken/West Java/Subang/29/2007 (clade 2.1.3) and A/chicken/Egypt/121/2012 (clade 2.2.1). Co-expression of these genes in Sf9 cells along with influenza neuraminidase (NA) and retrovirus gag genes resulted in production of triple-clade H555 VLPs that exhibited hemagglutination activity and morphologically resembled influenza virions. Vaccination of chickens with these VLPs resulted in induction of serum antibody responses and efficient protection against experimental challenges with three different viruses including the recent U.S. H5N8 HPAI isolate. We conclude that these novel triple-clade VLPs represent a feasible strategy for simultaneously evoking protective antibodies against multiple variants of H5 influenza virus.

  8. Cellular transcripts regulated during infections with Highly Pathogenic H5N1 Avian Influenza virus in 3 host systems

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    Noor Suriani M

    2011-04-01

    Full Text Available Abstract Background Highly pathogenic Avian Influenza (HPAI virus is able to infect many hosts and the virus replicates in high levels in the respiratory tract inducing severe lung lesions. The pathogenesis of the disease is actually the outcome of the infection as determined by complex host-virus interactions involving the functional kinetics of large numbers of participating genes. Understanding the genes and proteins involved in host cellular responses are therefore, critical for the elucidation of the mechanisms of infection. Methods Differentially expressed transcripts regulated in a H5N1 infections of whole lung organ of chicken, in-vitro chick embryo lung primary cell culture (CeLu and a continuous Madin Darby Canine Kidney cell line was undertaken. An improved mRNA differential display technique (Gene Fishing™ using annealing control primers that generates reproducible, authentic and long PCR products that are detectable on agarose gels was used for the identification of differentially expressed genes (DEGs. Seven of the genes have been selected for validation using a TaqMan® based real time quantitative PCR assay. Results Thirty seven known and unique differentially expressed genes from lungs of chickens, CeLu and MDCK cells were isolated. Among the genes isolated and identified include heat shock proteins, Cyclin D2, Prenyl (decaprenyl diphosphate synthase, IL-8 and many other unknown genes. The quantitative real time RT-PCR assay data showed that the transcription kinetics of the selected genes were clearly altered during infection by the Highly Pathogenic Avian Influenza virus. Conclusion The Gene Fishing™ technique has allowed for the first time, the isolation and identification of sequences of host cellular genes regulated during H5N1 virus infection. In this limited study, the differentially expressed genes in the three host systems were not identical, thus suggesting that their responses to the H5N1 infection may not share

  9. Avian influenza H5N1 viral and bird migration networks in Asia

    Science.gov (United States)

    Tian, Huaivu; Zhou, Sen; Dong, Lu; Van Boeckel, Thomas P.; Cui, Yujun; Newman, Scott H.; Takekawa, John Y.; Prosser, Diann J.; Xiao, Xiangming; Wu, Yarong; Cazelles, Bernard; Huang, Shanqian; Yang, Ruifu; Grenfell, Bryan T.; Xu, Bing

    2015-01-01

    The spatial spread of the highly pathogenic avian influenza virus H5N1 and its long-term persistence in Asia have resulted in avian influenza panzootics and enormous economic losses in the poultry sector. However, an understanding of the regional long-distance transmission and seasonal patterns of the virus is still lacking. In this study, we present a phylogeographic approach to reconstruct the viral migration network. We show that within each wild fowl migratory flyway, the timing of H5N1 outbreaks and viral migrations are closely associated, but little viral transmission was observed between the flyways. The bird migration network is shown to better reflect the observed viral gene sequence data than other networks and contributes to seasonal H5N1 epidemics in local regions and its large-scale transmission along flyways. These findings have potentially far-reaching consequences, improving our understanding of how bird migration drives the periodic reemergence of H5N1 in Asia.

  10. Gene expression responses to highly pathogenic avian influenza H5N1 virus infections in ducks

    Science.gov (United States)

    Differences in host response to infection with avian influenza (AI) viruses were investigated by identifying genes differentially expressed in tissues of infected ducks. Clear differences in pathogenicity were observed among ducks inoculated with five H5N1 HPAI viruses. Virus titers in tissues cor...

  11. The pause on avian H5N1 influenza virus transmission research should be ended

    NARCIS (Netherlands)

    R.A.M. Fouchier (Ron); A. García-Sastre (Adolfo); Y. Kawaoka (Yoshihiro)

    2012-01-01

    textabstractA voluntary 60-day pause on avian H5N1 influenza virus transmission research was announced in January 2012 by the international community of influenza scientists engaged in this work to provide time to explain the benefits of such work and the risk mitigation measures in place. Subsequen

  12. Genetic insight of the H5N1 hemagglutinin cleavage site

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The cleavability of the hemagglutinin (HA) plays a major role in virulence of avian influenza viruses. Detailed analyses of the cleavage sequences and their evolution would give insights into the high pathogenicity of the H5N1 virus. HA segments were visually identifiable in the cellular automata (CA) image, and a feature gene segment (FGS) was only found in H5N1 rather than any other subtype. This FGS is a 30-bp gene segment mainly consisting of 'A' and 'G'. When translated into amino acids the FGS converted into a sequence of mainly basic amino acids with positive charges. This feature amino acid segment (FAAS) was located in the cleavage site loop of HA which was potentially cleavable by various proteases. The 3D structure of H5N1 HA was reconstructed using homology modelling. It was found that the cleavage site loop was well exposed to potential proteases. The molecular surfaces were reconstructed to study how mutation and deletion of some amino acids in the FAAS affected the charge distribution. It was found that some mutations had severely changed the landscape of the charge distribution. Statistical analyses of FAAS were made with respect to when and where the H5N1 viruses were found. In 2005, there were less un-mutated FAAS than the other years according to temporal evolution, and more mutated FAAS appeared in China than other regions according to geographic distribution. These results are helpful for exploring the evolution of virus high pathogenicity.

  13. Ecological determinants of highly pathogenic avian influenza (H5N1) outbreaks in Bangladesh

    DEFF Research Database (Denmark)

    Ahmed, Syed Sayeem Uddin; Ersbøll, Annette Kjær; Biswas, Paritosh K.

    2012-01-01

    Background: The agro-ecology and poultry husbandry of the south Asian and south-east Asian countries share common features, however, with noticeable differences. Hence, the ecological determinants associated with risk of highly pathogenic avian influenza (HPAI-H5N1) outbreaks are expected to diff...

  14. Influenza A H5N1 and HIV co-infection: case report

    Directory of Open Access Journals (Sweden)

    Simmons Cameron

    2010-06-01

    Full Text Available Abstract Background The role of adaptive immunity in severe influenza is poorly understood. The occurrence of influenza A/H5N1 in a patient with HIV provided a rare opportunity to investigate this. Case Presentation A 30-year-old male was admitted on day 4 of influenza-like-illness with tachycardia, tachypnea, hypoxemia and bilateral pulmonary infiltrates. Influenza A/H5N1 and HIV tests were positive and the patient was treated with Oseltamivir and broad-spectrum antibiotics. Initially his condition improved coinciding with virus clearance by day 6. He clinically deteriorated as of day 10 with fever recrudescence and increasing neutrophil counts and died on day 16. His admission CD4 count was 100/μl and decreased until virus was cleared. CD8 T cells shifted to a CD27+CD28- phenotype. Plasma chemokine and cytokine levels were similar to those found previously in fatal H5N1. Conclusions The course of H5N1 infection was not notably different from other cases. Virus was cleared despite profound CD4 T cell depletion and aberrant CD8 T cell activation but this may have increased susceptibility to a fatal secondary infection.

  15. Avian Influenza Virus A (H5N1), Detected through Routine Surveillance, in Child, Bangladesh

    Science.gov (United States)

    Alamgir, A.S.M.; Sultana, Rebecca; Islam, M. Saiful; Rahman, Mustafizur; Fry, Alicia M.; Shu, Bo; Lindstrom, Stephen; Nahar, Kamrun; Goswami, Doli; Haider, M. Sabbir; Nahar, Sharifun; Butler, Ebonee; Hancock, Kathy; Donis, Ruben O.; Davis, Charles T.; Zaman, Rashid Uz; Luby, Stephen P.; Uyeki, Timothy M.; Rahman, Mahmudur

    2009-01-01

    We identified avian influenza virus A (H5N1) infection in a child in Bangladesh in 2008 by routine influenza surveillance. The virus was of the same clade and phylogenetic subgroup as that circulating among poultry during the period. This case illustrates the value of routine surveillance for detection of novel influenza virus. PMID:19751601

  16. Rapid detection of the avian influenza virus H5N1 subtype in Egypt ...

    African Journals Online (AJOL)

    Rapid detection of the avian influenza virus H5N1 subtype in Egypt. ... Effective diagnosis and control management are needed to control the disease. ... rabbit serum, which secrete immunoglobulin G (IgG) was served as the detector antibody ...

  17. Distribution of avian influenza H5N1 viral RNA in tissues of AI-vaccinated and unvaccinated contact chickens after experimental infection.

    Science.gov (United States)

    Hassan, Mohamed K; Kilany, Walid H; Abdelwhab, E M; Arafa, Abdel-Satar; Selim, Abdullah; Samy, Ahmed; Samir, M; Le Brun, Yvon; Jobre, Yilma; Aly, Mona M

    2012-05-01

    Avian influenza due to highly pathogenic avian influenza (HPAIV) H5N1 virus is not a food-borne illness but a serious panzootic disease with the potential to be pandemic. In this study, broiler chickens were vaccinated with commercial H5N1 or H5N2 inactivated vaccines prior to being challenged with an HPAIV H5N1 (clade 2.2.1 classic) virus. Challenged and non-challenged vaccinated chickens were kept together, and unvaccinated chickens served as contact groups. Post-challenge samples from skin and edible internal organs were collected from dead and sacrificed (after a 14-day observation period) birds and tested using qRT-PCR for virus detection and quantification. H5N1 vaccine protected chickens against morbidity, mortality and transmission. Virus RNA was not detected in the meat or edible organs of chickens vaccinated with H5N1 vaccine. Conversely, H5N2 vaccine did not confer clinical protection, and a significant virus load was detected in the meat and internal organs. Phylogenetic analysis showed that the H5N1 virus vaccine and challenge virus strains are closely related. The results of the present study strongly suggest a need for proper selection of vaccines and their routine evaluation against newly emergent field viruses. These actions will help to reduce human exposure to HPAIV H5N1 virus from both infected live birds and slaughtered poultry. In addition, rigorous preventive measures should be put in place in order to minimize the public-health risks of avian influenza at the human-animal interface.

  18. Analysis of the crow lung transcriptome in response to infection with highly pathogenic H5N1 avian influenza virus.

    Science.gov (United States)

    Vijayakumar, Periyasamy; Mishra, Anamika; Ranaware, Pradip B; Kolte, Atul P; Kulkarni, Diwakar D; Burt, David W; Raut, Ashwin Ashok

    2015-03-15

    The highly pathogenic avian influenza (HPAI) H5N1 virus, currently circulating in Asia, causes severe disease in domestic poultry as well as wild birds like crow. However, the molecular pathogenesis of HPAIV infection in crows and other wild birds is not well known. Thus, as a step to explore it, a comprehensive global gene expression analysis was performed on crow lungs, infected with HPAI H5N1 crow isolate (A/Crow/India/11TI11/2011) using high throughput next generation sequencing (NGS) (GS FLX Titanium XLR70). The reference genome of crow is not available, so RNA seq analysis was performed on the basis of a de novo assembled transcriptome. The RNA seq result shows, 4052 genes were expressed uniquely in noninfected, 6277 genes were expressed uniquely in HPAIV infected sample and of the 6814 genes expressed in both samples, 2279 genes were significantly differentially expressed. Our transcriptome profile data allows for the ability to understand the molecular mechanism behind the recent lethal HPAIV outbreak in crows which was, until recently, thought to cause lethal infections only in gallinaceous birds such as chickens, but not in wild birds. The pattern of differentially expressed genes suggest that this isolate of H5N1 virus evades the host innate immune response by attenuating interferon (IFN)-inducible signalling possibly by down regulating the signalling from type I IFN (IFNAR1 and IFNAR2) and type II IFN receptors, upregulation of the signalling inhibitors suppressor of cytokine signalling 1 (SOCS1) and SOCS3 and altering the expression of toll-like receptors (TLRs). This may be the reason for disease and mortality in crows. Copyright © 2015. Published by Elsevier B.V.

  19. A Meta-Analysis of the Prevalence of Influenza A H5N1 and H7N9 Infection in Birds.

    Science.gov (United States)

    Bui, C; Rahman, B; Heywood, A E; MacIntyre, C R

    2016-01-10

    Despite a much higher rate of human influenza A (H7N9) infection compared to influenza A (H5N1), and the assumption that birds are the source of human infection, detection rates of H7N9 in birds are lower than those of H5N1. This raises a question about the role of birds in the spread and transmission of H7N9 to humans. We conducted a meta-analysis of overall prevalence of H5N1 and H7N9 in different bird populations (domestic poultry, wild birds) and different environments (live bird markets, commercial poultry farms, wild habitats). The electronic database, Scopus, was searched for published papers, and Google was searched for country surveillance reports. A random effect meta-analysis model was used to produce pooled estimates of the prevalence of H5N1 and H7N9 for various subcategories. A random effects logistic regression model was used to compare prevalence rates between H5N1 and H7N9. Both viruses have low prevalence across all bird populations. Significant differences in prevalence rates were observed in domestic birds, farm settings, for pathogen and antibody testing, and during routine surveillance. Random effects logistic regression analyses show that among domestic birds, the prevalence of H5N1 is 47.48 (95% CI: 17.15-133.13, P H7N9. In routine surveillance (where surveillance was not conducted in response to human infections or bird outbreaks), the prevalence of H5N1 is still higher than H7N9 with an OR of 43.02 (95% CI: 16.60-111.53, P H7N9 in humans has occurred at a rate approximately four times higher than H5N1, and for both infections, birds are postulated to be the source. Much lower rates of H7N9 in birds compared to H5N1 raise doubts about birds as the sole source of high rates of human H7N9 infection. Other sources of transmission of H7N9 need to be considered and explored.

  20. Evolution of highly pathogenic avian H5N1 influenza viruses

    Energy Technology Data Exchange (ETDEWEB)

    Macken, Catherine A [Los Alamos National Laboratory; Green, Margaret A [Los Alamos National Laboratory

    2009-01-01

    Highly pathogenic avian H5N1 viruses have circulated in Southeast Asia for more than a decade, are now endemic in parts of this region, and have also spread to more than 60 countries on three continents. The evolution of these viruses is characterized by frequent reassortment events that have created a significant number of different genotypes, both transient and longer lasting. However, fundamental questions remain about the generation and perpetuation of this substantial genetic diversity. These gaps in understanding may, in part, be due to the difficulties of genotyping closely related viruses, and limitations in the size of the data sets used in analysis. Using our recently published novel genotyping procedure ('two-time test'), which is amenable to high throughput analysis and provides an increased level of resolution relative to previous analyses, we propose a detailed model for the evolution and diversification of avian H5N1 viruses. Our analysis suggests that (i) all current H5N1 genotypes are derived from a single, clearly defined sequence of initial reassortment events; (ii) reassortment of the polymerase and NP genes may have played an important role in avian H5N1 virus evolution; (iii) the current genotype Z viruses have diverged into three distinguishable sub-genotypes in the absence of reassortment; (iv) some potentially significant molecular changes appear to be correlated with particular genotypes (for example, reassortment of the internal genes is often paralleled by a change in the HA clade); and (v) as noted in earlier studies of avian influenza A virus evolution, novel segments are typically derived from different donors (i.e., there is no obvious pattern of gene linkage in reassortment). The model of avian H5N1 viral evolution by reassortment and mutation that emerges from our study provides a context within which significant amino acid changes may be revealed; it also may help in predicting the 'success' of newly emerging

  1. Cellular transcripts of chicken brain tissues in response to H5N1 and Newcastle disease virus infection

    Directory of Open Access Journals (Sweden)

    Balasubramaniam Vinod RMT

    2012-02-01

    Full Text Available Abstract Background Highly-pathogenic avian influenza (HPAI H5N1 and Newcastle disease (ND viruses are the two most important poultry viruses in the world, with the ability to cause classic central nervous system dysfunction in poultry and migratory birds. To elucidate the mechanisms of neurovirulence caused by these viruses, a preliminary study was design to analyze host's cellular responses during infections of these viruses. Methods An improved mRNA differential display technique (Gene Fishing™ was undertaken to analyze differentially expressed transcripts regulated during HPAI H5N1 and velogenic neurotropic NDV infections of whole brain of chickens. The identification of differentially expressed genes (DEGs was made possible as this technique uses annealing control primers that generate reproducible, authentic and long PCR products that are detectable on agarose gels. Results Twenty-three genes were identified to be significantly regulated during infections with both viruses, where ten of the genes have been selected for validation using a TaqMan® based real time quantitative PCR assay. Some of the identified genes demonstrated to be key factors involving the cytoskeletal system, neural signal transduction and protein folding during stress. Interestingly, Septin 5, one of the genes isolated from HPAI H5N1-infected brain tissues has been reported to participate in the pathogenic process of Parkinson's disease. Conclusions In this limited study, the differentially expressed genes of infected brain tissues regulated by the viruses were found not to be identical, thus suggesting that their neurovirulence and neuropathogenesis may not share similar mechanisms and pathways.

  2. A single vaccination of commercial broilers does not reduce transmission of H5N1 highly pathogenic avian influenza

    Directory of Open Access Journals (Sweden)

    Poetri Okti

    2011-06-01

    Full Text Available Abstract Vaccination of chickens has become routine practice in Asian countries in which H5N1 highly pathogenic avian influenza (HPAI is endemically present. This mainly applies to layer and breeder flocks, but broilers are usually left unvaccinated. Here we investigate whether vaccination is able to reduce HPAI H5N1 virus transmission among broiler chickens. Four sets of experiments were carried out, each consisting of 22 replicate trials containing a pair of birds. Experiments 1-3 were carried out with four-week-old birds that were unvaccinated, and vaccinated at day 1 or at day 10 of age. Experiment 4 was carried out with unvaccinated day-old broiler chicks. One chicken in each trial was inoculated with H5N1 HPAI virus. One chicken in each trial was inoculated with virus. The course of the infection chain was monitored by serological analysis, and by virus isolation performed on tracheal and cloacal swabs. The analyses were based on a stochastic SEIR model using a Bayesian inferential framework. When inoculation was carried out at the 28th day of life, transmission was efficient in unvaccinated birds, and in birds vaccinated at first or tenth day of life. In these experiments estimates of the latent period (~1.0 day, infectious period (~3.3 days, and transmission rate parameter (~1.4 per day were similar, as were estimates of the reproduction number (~4 and generation interval (~1.4 day. Transmission was significantly less efficient in unvaccinated chickens when inoculation was carried out on the first day of life. These results show that vaccination of broiler chickens does not reduce transmission, and suggest that this may be due to the interference of maternal immunity.

  3. Informal inter-island poultry movement in Indonesia: does it pose a risk to HPAI H5N1 transmission?

    Science.gov (United States)

    Millar, Joanne; Abdurrahman, Muktasam; Toribio, Jenny-Ann; Ambarawati, Annie; Yusuf, Ria Puspa; Suadnya, Wayan

    2015-10-01

    Informal movement of domesticated poultry and wild birds is considered a major threat in terms of highly pathogenic avian influenza (HPAI) H5N1 transmission between birds and from birds to humans. However, the risk of transmission from informal illegal poultry movement has received little attention in Indonesia where human fatalities are the highest in the world. This research investigated the illegal movement of adult poultry between the islands of Java, Bali and Lombok to determine the potential risk of HPAI H5N1 transmission. The aim was to determine known origins and destinations of poultry, estimated quantity and types of birds, people involved and the drivers of illegal movement. Transportation and handling methods and views on how to minimise illegal movement were also investigated. In-depth interviews were carried out with 71 key informants in Bali and Lombok in 2009. East Java was the main origin of poultry entering Bali, followed by Central Java and Lombok. Interviewees estimated that over 10,000 village chickens, 500 ducks and 50 fighting cocks were brought into Bali per month from all origins. However, there were significant discrepancies with quarantine records indicating that the majority of birds imported illegally are not detected. We conclude that although informal illegal movement of poultry in Indonesia poses a potentially high risk for potential HPAI H5N1 transmission if birds are infected, much can be done to increase surveillance, encourage reporting of sick birds, educate traders about the risks and provide effective quarantine within an appropriate cultural framework.

  4. Respon Imun Itik Bali terhadap Berbagai Dosis Vaksin Avian Influenza H5N1

    Directory of Open Access Journals (Sweden)

    Ida Bagus Kade Suardana

    2009-09-01

    Full Text Available A study was carried out to investigate the immune response of Bali ducks against various doses ofAvian Influenza H5N1 vaccine. The study was carried out using a complete Random-Split in Time researchdesign as many as 40 of Bali ducks of 3 months age were kept separately in 4 groups. The ducks werevaccinated twice in two week interval with AI H5N1 vaccine of 0 (as negative control, 1/2, 1, and 2 doses.Sera were collected one day before first vaccination, then every week until three weeks after the secondvaccination. All sera were tested by hemaglutination inhibition (HI test. The result shows that antibodylevel with double dose was significantly higher than single dose, half dose, and negative control (P<0.01.However antibody level in ducks vaccinated with single and half dose did not show any significant difference(P > 0.05.

  5. siRNAs targeting PB2 and NP genes potentially inhibit replication of Highly Pathogenic H5N1 Avian Influenza Virus.

    Science.gov (United States)

    Behera, Padmanava; Nagarajan, Shanmugasundaram; Murugkar, Harshad V; Kalaiyarasu, Semmannan; Prakash, Anil; Gothalwal, Ragini; Dubey, Shiv Chandra; Kulkarni, Diwakar D; Tosh, Chakradhar

    2015-06-01

    Highly Pathogenic Avian Influenza (HPAI) H5N1 virus is a threat to animal and public health worldwide. Till date, the H5N1 virus has claimed 402 human lives, with a mortality rate of 58 percent and has caused the death or culling of millions of poultry since 2003. In this study, we have designed three siRNAs (PB2-2235, PB2-479 and NP-865) targeting PB2 and NP genes of avian influenza virus and evaluated their potential, measured by hemagglutination (HA), plaque reduction and Real time RT-PCR assay, in inhibiting H5N1 virus (A/chicken/Navapur/7972/2006) replication in MDCK cells. The siRNAs caused 8- to 16-fold reduction in virus HA titers at 24 h after challenged with 100TCID50 of virus. Among these siRNAs, PB2-2235 offered the highest inhibition of virus replication with 16-fold reduction in virus HA titer, 80 percent reduction in viral plaque counts and 94 percent inhibition in expression of specific RNA at 24 h. The other two siRNAs had 68-73 percent and 87-88 percent reduction in viral plaque counts and RNA copy number, respectively. The effect of siRNA on H5N1 virus replication continued till 48h (maximum observation period). These findings suggest that PB2-2235 could efficiently inhibit HPAI H5N1 virus replication.

  6. Specific detection of H5N1 avian influenza A virus in field specimens by a one-step RT-PCR assay

    Directory of Open Access Journals (Sweden)

    Gupta Sanjay

    2006-03-01

    Full Text Available Abstract Background Continuous outbreaks of the highly pathogenic H5N1 avian influenza A in Asia has resulted in an urgent effort to improve current diagnostics to aid containment of the virus and lower the threat of a influenza pandemic. We report here the development of a PCR-based assay that is highly specific for the H5N1 avian influenza A virus. Methods A one-step reverse-transcription PCR assay was developed to detect the H5N1 avian influenza A virus. The specificity of the assay was shown by testing sub-types of influenza A virus and other viral and bacterial pathogens; and on field samples. Results Validation on 145 field specimens from Vietnam and Malaysia showed that the assay was specific without cross reactivity to a number of other infuenza strains as well as human respiratory related pathogens. Detection was 100% from allantoic fluid in H5N1 positive samples, suggesting it to be a reliable sampling source for accurate detection. Conclusion The assay developed from this study indicates that the primers are specific for the H5N1 influenza virus. As shown by the field tested results, this assay would be highly useful as a diagnostic tool to help identify and control influenza epidemics.

  7. siRNAs targeting PB2 and NP genes potentially inhibit replication of Highly Pathogenic H5N1 Avian Influenza Virus

    Indian Academy of Sciences (India)

    Padmanava Behera; Shanmugasundaram Nagarajan; Harshad V Murugkar; Semmannan Kalaiyarasu; Anil Prakash; Ragini Gothalwal; Shiv Chandra Dubey; Diwakar D Kulkarni; Chakradhar Tosh

    2015-06-01

    Highly Pathogenic Avian Influenza (HPAI) H5N1 virus is a threat to animal and public health worldwide. Till date, the H5N1 virus has claimed 402 human lives, with a mortality rate of 58% and has caused the death or culling of millions of poultry since 2003. In this study, we have designed three siRNAs (PB2-2235, PB2-479 and NP-865) targeting PB2 and NP genes of avian influenza virus and evaluated their potential, measured by hemagglutination (HA), plaque reduction and Real time RT-PCR assay, in inhibiting H5N1 virus (A/chicken/Navapur/7972/2006) replication in MDCK cells. The siRNAs caused 8- to 16-fold reduction in virus HA titers at 24 h after challenged with 100TCID50 of virus. Among these siRNAs, PB2-2235 offered the highest inhibition of virus replication with 16-fold reduction in virus HA titer, 80% reduction in viral plaque counts and 94% inhibition in expression of specific RNA at 24 h. The other two siRNAs had 68–73% and 87–88% reduction in viral plaque counts and RNA copy number, respectively. The effect of siRNA on H5N1 virus replication continued till 48h (maximum observation period). These findings suggest that PB2-2235 could efficiently inhibit HPAI H5N1 virus replication.

  8. Prevention and control of highly pathogenic avian influenza with particular reference to H5N1.

    Science.gov (United States)

    Capua, Ilaria; Cattoli, Giovanni

    2013-12-05

    Highly pathogenic avian influenza viruses of the H5N1 subtype emerged in Far East Asia in 1996 and spread in three continents in a period of 10 or less years. Before this event, avian influenza infections caused by highly pathogenic viruses had occurred in many different countries, causing minor or major outbreaks, and had always been eradicated. The unique features of these H5N1 viruses combined to the geographic characteristics of the area of emergence, including animal husbandry practices, has caused this subtype to become endemic in several Asian countries, as well as in Egypt. Our aim is to review the direct and indirect control strategies with the rationale for use, advantages and shortcomings - particularly resulting from practicalities linked to field application and economic constraints. Certainly, in low income countries which have applied vaccination, this has resulted in a failure to eradicate the infection. Although the number of infected countries has dropped from over 40 (2006) to under 10 (2012), the extensive circulation of H5N1 in areas with high poultry density still represents a risk for public and animal health.

  9. Indium-tin-oxide thin film transistor biosensors for label-free detection of avian influenza virus H5N1

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Di; Zhuo, Ming [Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education, State Key Laboratory for Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China); Zhang, Xiaoai [State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing (China); Xu, Cheng; Jiang, Jie [Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education, State Key Laboratory for Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China); Gao, Fu [State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing (China); Wan, Qing, E-mail: wanqing7686@hotmail.com [Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education, State Key Laboratory for Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China); Li, Qiuhong, E-mail: liqiuhong2004@hotmail.com [Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education, State Key Laboratory for Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China); Wang, Taihong, E-mail: thwang@hnu.cn [Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education, State Key Laboratory for Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China)

    2013-04-22

    Highlights: ► A highly selective label-free biosensor is established based on indium-tin-oxide thin-film transistors (ITO TFTs). ► AI H5N1 virus was successfully detected through shift in threshold voltage and field-effect mobility of ITO TFT. ► The ITO TFT is applied in biosensor for the first time and shows good reusability and stability. ► Fabrication of the platform is simple with low cost, which is suitable for mass commercial production. -- Abstract: As continuous outbreak of avian influenza (AI) has become a threat to human health, economic development and social stability, it is urgently necessary to detect the highly pathogenic avian influenza H5N1 virus quickly. In this study, we fabricated indium-tin-oxide thin-film transistors (ITO TFTs) on a glass substrate for the detecting of AI H5N1. The ITO TFT is fabricated by a one-shadow-mask process in which a channel layer can be simultaneously self-assembled between ITO source/drain electrodes during magnetron sputtering deposition. Monoclonal anti-H5N1 antibodies specific for AI H5N1 virus were covalently immobilized on the ITO channel by (3-glycidoxypropyl)trimethoxysilane. The introduction of target AI H5N1 virus affected the electronic properties of the ITO TFT, which caused a change in the resultant threshold voltage (V{sub T}) and field-effect mobility. The changes of I{sub D}–V{sub G} curves were consistent with an n-type field effect transistor behavior affected by nearby negatively charged AI H5N1 viruses. The transistor based sensor demonstrated high selectivity and stability for AI H5N1 virus sensing. The sensor showed linear response to AI H5N1 in the concentrations range from 5 × 10{sup −9} g mL{sup −1} to 5 × 10{sup −6} g mL{sup −1} with a detection limit of 0.8 × 10{sup −10} g mL{sup −1}. Moreover, the ITO TFT biosensors can be repeatedly used through the washing processes. With its excellent electric properties and the potential for mass commercial production, ITO TFTs

  10. Influenza H5N1 and H1N1 virus replication and innate immune responses in bronchial epithelial cells are influenced by the state of differentiation.

    Directory of Open Access Journals (Sweden)

    Renee W Y Chan

    Full Text Available Influenza H5N1 virus continues to be enzootic in poultry and transmits zoonotically to humans. Although a swine-origin H1N1 virus has emerged to become pandemic, its virulence for humans remains modest in comparison to that seen in zoonotic H5N1 disease. As human respiratory epithelium is the primary target cells for influenza viruses, elucidating the viral tropism and host innate immune responses of influenza H5N1 virus in human bronchial epithelium may help to understand the pathogenesis. Here we established primary culture of undifferentiated and well differentiated normal human bronchial epithelial (NHBE cells and infected with highly pathogenic influenza H5N1 virus (A/Vietnam/3046/2004 and a seasonal influenza H1N1 virus (A/Hong Kong/54/1998, the viral replication kinetics and cytokine and chemokine responses were compared by qPCR and ELISA. We found that the in vitro culture of the well differentiated NHBE cells acquired the physiological properties of normal human bronchi tissue which express high level of alpha2-6-linked sialic acid receptors and human airway trypsin-like (HAT protease, in contrast to the low expression in the non-differentiated NHBE cells. When compared to H1N1 virus, the H5N1 virus replicated more efficiently and induced a stronger type I interferon response in the undifferentiated NHBE cells. In contrast, in well differentiated cultures, H5N1 virus replication was less efficient and elicited a lower interferon-beta response in comparison with H1N1 virus. Our data suggest that the differentiation of bronchial epithelial cells has a major influence in cells' permissiveness to human H1N1 and avian H5N1 viruses and the host innate immune responses. The reduced virus replication efficiency partially accounts for the lower interferon-beta responses in influenza H5N1 virus infected well differentiated NHBE cells. Since influenza infection in the bronchial epithelium will lead to tissue damage and associate with the

  11. 甲型H5N1和H7N9禽流感——关注2013年H7N9禽流感疫情%A(H5N1) and A (H7N9) avian influenza: the H7N9 avian influenza outbreak of 2013

    Institute of Scientific and Technical Information of China (English)

    王荃; 姚开虎

    2013-01-01

    influenza virus can infect humans and cause disease.The clinical presentation of human infection is usually mild,but the infection caused by A(H5N1) avian influenza virus occurring initially in Hongkong in 1997 or the A(H7N9)virus isolated first at the beginning of this year in China is severe and characterized by high mortality.The mortality rate of adolescents and children caused by H5N1 avian influenza is lower than that of adults and the younger the child the lower the mortality rate.A few pediatric H7N9 avian influenza cases recovered soon after treatment.A child was determined to be a H7N9 avian influenza virus carrier.These findings suggested that the pediatric H7N9 avian influenza infection was mild.It is very important to start anti-virus treatment with oseltamivir as early as possible in cases of avian influenza infection is considered.Combined therapy,including respiratory and circulatory support and inhibiting immunological reaction,is emphasized in the treatment of severe cases.%禽流感病毒可以感染人类,通常病情轻微,1997年出现的H5N1禽流感和本年初出现的H7N9禽流感病情严重,病死率高.青少年和儿童H5N1禽流感病死率低于成人,年龄越小,病死率越低.有限的儿童病例经治疗迅速康复,以及儿童携带者的发现提示儿童H7N9禽流感病情轻微.禽流感治疗强调尽早使用奥司他韦进行抗病毒治疗,重症者需积极的呼吸支持、循环支持和抑制免疫反应等综合治疗.

  12. Lessons from emergence of A/goose/Guangdong/1996-like H5N1 highly pathogenic avian influenza viruses and recent influenza surveillance efforts in southern China.

    Science.gov (United States)

    Wan, X F

    2012-09-01

    Southern China is proposed as an influenza epicentre. At least two of the three pandemics in the last century, including 1957 and 1968 influenza pandemics, originated from this area. In 1996, A/goose/Guangdong/1/1996 (H5N1), the precursor of currently circulating highly pathogenic H5N1 avian influenza viruses (HPAIVs) was identified in farmed geese in southern China. These H5N1 HPAIVs have been spread across Asia, Europe and Africa and poses a continuous threat to both animal and human health. However, how and where this H5N1 HPAIV emerged are not fully understood. In the past decade, many influenza surveillance efforts have been carried out in southern China, and our understanding of the genetic diversity of non-human influenza A viruses in this area has been much better than ever. Here, the historical and first-hand experimental data on A/goose/Guangdong/1/1996(H5N1)-like HPAIVs are reviewed within the context of the findings from recent surveillance efforts on H5N1 HPAIVs and other non-human influenza A viruses. Such a retrospective recapitulation suggests that long-term and systematic surveillance programmes should continue to be implemented in southern China that the wet markets on the animal-human interface shall be the priority area and that the surveillance on the animal species bridging the interface between wildlife and domestic animal populations and the interface between the aquatics and territories shall be the strengthened.

  13. Environmental sampling for avian influenza virus A (H5N1) in live-bird markets, Indonesia.

    Science.gov (United States)

    Indriani, Risa; Samaan, Gina; Gultom, Anita; Loth, Leo; Irianti, Sri; Indryani, Sri; Adjid, Rma; Dharmayanti, Ni Luh Putu Indi; Weaver, John; Mumford, Elizabeth; Lokuge, Kamalini; Kelly, Paul M; Darminto

    2010-12-01

    To identify environmental sites commonly contaminated by avian influenza virus A (H5N1) in live-bird markets in Indonesia, we investigated 83 markets in 3 provinces in Indonesia. At each market, samples were collected from up to 27 poultry-related sites to assess the extent of contamination. Samples were tested by using real-time reverse transcription-PCR and virus isolation. A questionnaire was used to ascertain types of birds in the market, general infrastructure, and work practices. Thirty-nine (47%) markets showed contamination with avian influenza virus in ≥ 1 of the sites sampled. Risk factors were slaughtering birds in the market and being located in West Java province. Protective factors included daily removal of waste and zoning that segregated poultry-related work flow areas. These results can aid in the design of evidence-based programs concerning environmental sanitation, food safety, and surveillance to reduce the risk for avian influenza virus A (H5N1) transmission in live-bird markets.

  14. Protection level of AI H5N1 vaccine clade 2.1.3 commercial against AI H5N1 clade 2.3.2 virus from Ducks to SPF chicken in laboratory conditions

    Directory of Open Access Journals (Sweden)

    Indriani R

    2015-03-01

    Full Text Available Highly Pathogenic Avian Influenza (HPAI subtype H5N1 clade 2.3.2 has infected chickens in farms, causing mortality and a decrease in egg production. Vaccination is one of the strategies to control disease of AI subtype H5N1. AI H5N1 clade 2.1.3 vaccine is available commercially. The effectiveness of two vaccines of AI H5N1 clade 2.1.3 (product A and B, and AI H5N1 clade 2.3.2 (Sukoharjo against AI H5N1 clade 2.3.2 (Sukoharjo virus SPF chickens was tested in laboratory. Four groups of SPF chickens were used in this study, there were (1 vaccinated with H5N1 clade 2.1.3 (product A, (2 vaccinated with H5N1 clade 2.1.3 (product B, (3 vaccinated with AI H5N1 clade 2.3.2 and (4 unvaccinated (as a control. Each vaccinated group consisted of 10 chicken except 8 chicken for control group. SPF chicken were vaccinated with 1 dose of vaccine at 3 weeks olds, and then after 3 weeks post vaccination (at 6 weeks olds. All group of chicken were challenged with 106 EID50 per 0.1 ml via intranasal. The results showed, chicken vaccinated with H5N1 clade 2.1.3 product A and B gave 100 and 80% protection respectively, but showed challenged virus shedding, whereas vaccine of H5N1 clade 2.3.2 gave 100% protection from mortality and without virus shedding. Vaccines of AI H5N1 clade 2.1.3 product A was better than vaccine product B, and when chicken vaccinated against H5N1 clade 2.3.2, H5N1 clade 2.3.2 vaccine was the best to be used. In order to protect chicken from AI subtype H5N1 clade 2.1.3 and 2.3.2 in the field, a bivalent vaccine of H5N1 clade 2.1.3 and 2.3.2 subtypes should be developed.

  15. Immunomorphologic Manifestations in Mice Liver Infected with Influenza A/H5N1, A/Goose/Krasnoozerskoye/627/05 Strain

    Directory of Open Access Journals (Sweden)

    Oxana V. Potapova

    2013-01-01

    Full Text Available Highly pathogenic avian influenza H5N1 (HPAI H5N1 viruses can infect mammals, including humans, causing severe systemic disease with the inhibition of the immune system and a high mortality rate. In conditions of lymphoid tissue depletion, the liver plays an important role in host defence against viruses. The changes in mice liver infected with HPAI H5N1 virus A/goose/Krasnoozerskoye/627/05 have been studied. It has been shown that the virus persistence in the liver leads to the expression of proinflammatory cytokines (TNF-α, IL-6 and intracellular proteases (lysozyme, cathepsin D, and myeloperoxidase by Kupffer cells. Defective antiviral response exacerbates destructive processes in the liver accelerating the development of liver failure.

  16. Detection of antibody responses by using haemagglutination inhibiton test and the protection titer of avian influenza virus H5N1 subtype

    Directory of Open Access Journals (Sweden)

    Risa Indriani

    2004-10-01

    Full Text Available Study on the detection of antibody responses using haemagglutination inhibition (HI test and the protection titer to Avian influenza (AI virus H5N1 subtype local isolate has been conducted at the Research Institute for Veterinary Science (RIVS. A total number of 50 village chicken (10 chicken served as un-injected controls and 30 quail were injected intramuscularly with inactivated virus of AI H5N1 subtype local isolate. Serum samples were collected 3 weeks after injection and were tested using haemagglutination inhibition tests. The correlation between antibody titer and its protection to AI virus H5N1 local isolate were measured by challenging the birds with AI virus H5N1 local isolate The HI test was then used to determine field serum samples. A total number of 48 village chicken from three (3 Districts (Bekasi, Tangerang and Bogor and 96 quails from two (2 farms in District of Sukabumi which were all vaccinated with commercial AI adjuvant vaccine were sampled. The study revealed that village chicken and quails showed antibody responses after 3 weeks vaccination and that titer of ≥ 3 log 2 was able to protect chicken and quails when they were challenged with local isolate virus. Based on this result, village chicken field samples from Districts of Tangerang, Bekasi and Bogor showed antibody titer which will protect 50, 100 and 85% of the flocks respectively. While quail field samples from Farm I and Farm II in District of Sukabumi showed antibody titer which will protect 60-100% and 0-80% of the flocks respectively. It is concluded that the study has successfully measured antibody titer to AI virus H5N1 subtype which protect village chicken and quails from local isolate virus challenge so that the results will be used to analyze field serum samples after vaccination program to eradicate AI from Indonesia.

  17. Comparing introduction to Europe of highly pathogenic avian influenza viruses A(H5N8) in 2014 and A(H5N1) in 2005.

    Science.gov (United States)

    Adlhoch, C; Gossner, C; Koch, G; Brown, I; Bouwstra, R; Verdonck, F; Penttinen, P; Harder, T

    2014-12-18

    Since the beginning of November 2014, nine outbreaks of highly pathogenic avian influenza virus (HPAIV) A(H5N8) in poultry have been detected in four European countries. In this report, similarities and differences between the modes of introduction of HPAIV A(H5N1) and A(H5N8) into Europe are described. Experiences from outbreaks of A(H5N1) in Europe demonstrated that early detection to control HPAIV in poultry has proven pivotal to minimise the risk of zoonotic transmission and prevention of human cases.

  18. 中国大陆H5N1亚型人禽流感流行病学分析

    Institute of Scientific and Technical Information of China (English)

    王敏; 许培扬; 池慧; 曹志新; 王辰

    2009-01-01

    人高致病性禽流行性感冒,简称人禽流感(human avian influenza),是由禽甲型流感病毒中某些亚型毒株突破种属感染人而引起的一种急性呼吸道传染病。目前常见的亚型有H5N1、H7N7和H9N2,其中以H5N1毒性最强。

  19. Predicting Avian Influenza Co-Infection with H5N1 and H9N2 in Northern Egypt.

    Science.gov (United States)

    Young, Sean G; Carrel, Margaret; Malanson, George P; Ali, Mohamed A; Kayali, Ghazi

    2016-01-01

    Human outbreaks with avian influenza have been, so far, constrained by poor viral adaptation to non-avian hosts. This could be overcome via co-infection, whereby two strains share genetic material, allowing new hybrid strains to emerge. Identifying areas where co-infection is most likely can help target spaces for increased surveillance. Ecological niche modeling using remotely-sensed data can be used for this purpose. H5N1 and H9N2 influenza subtypes are endemic in Egyptian poultry. From 2006 to 2015, over 20,000 poultry and wild birds were tested at farms and live bird markets. Using ecological niche modeling we identified environmental, behavioral, and population characteristics of H5N1 and H9N2 niches within Egypt. Niches differed markedly by subtype. The subtype niches were combined to model co-infection potential with known occurrences used for validation. The distance to live bird markets was a strong predictor of co-infection. Using only single-subtype influenza outbreaks and publicly available ecological data, we identified areas of co-infection potential with high accuracy (area under the receiver operating characteristic (ROC) curve (AUC) 0.991).

  20. Using risk assessment as part of a systems approach to the control and prevention of HPAIV H5N1.

    Science.gov (United States)

    Costard, Solenne; Fournié, Guillaume; Pfeiffer, Dirk Udo

    2014-01-01

    Since its emergence in China in 1996, highly pathogenic avian influenza virus subtype H5N1 has spread across Asia, Africa, and Europe. Countries had to promptly implement control and prevention measures. Numerous research and capacity building initiatives were conducted in the affected regions to improve the capacity of national animal health services to support the development of risk-based mitigation strategies. This paper reviews and discusses risk assessments initiated in several South-East Asian and African countries under one of these projects. Despite important data gaps, the risk assessment results improved the ability of policy makers to design appropriate risk management policies. Disease risk was strongly influenced by various human behavioral factors. The ongoing circulation of HPAIV H5N1 in several Asian countries and in Egypt, despite major disease control efforts, supports the need for an interdisciplinary approach to development of tailored risk management policies, in accordance with the EcoHealth paradigm and the broad concept of risk governance. In particular, active stakeholders engagement and integration of economic and social studies into the policy making process are needed to optimize compliance and sustainable behavioral changes, thereby increasing the effectiveness of mitigation strategies.

  1. Predicting Avian Influenza Co-Infection with H5N1 and H9N2 in Northern Egypt

    Directory of Open Access Journals (Sweden)

    Sean G. Young

    2016-09-01

    Full Text Available Human outbreaks with avian influenza have been, so far, constrained by poor viral adaptation to non-avian hosts. This could be overcome via co-infection, whereby two strains share genetic material, allowing new hybrid strains to emerge. Identifying areas where co-infection is most likely can help target spaces for increased surveillance. Ecological niche modeling using remotely-sensed data can be used for this purpose. H5N1 and H9N2 influenza subtypes are endemic in Egyptian poultry. From 2006 to 2015, over 20,000 poultry and wild birds were tested at farms and live bird markets. Using ecological niche modeling we identified environmental, behavioral, and population characteristics of H5N1 and H9N2 niches within Egypt. Niches differed markedly by subtype. The subtype niches were combined to model co-infection potential with known occurrences used for validation. The distance to live bird markets was a strong predictor of co-infection. Using only single-subtype influenza outbreaks and publicly available ecological data, we identified areas of co-infection potential with high accuracy (area under the receiver operating characteristic (ROC curve (AUC 0.991.

  2. The preliminary screening of different adjuvants in transcutaneous immunization with inactivated human highly pathogenic avian influenza vaccine%高致病性人禽流感H5N1透皮疫苗免疫佐剂的初步筛选

    Institute of Scientific and Technical Information of China (English)

    孙艳丽; 孙艳花; 马安伦; 鹿文葆; 陈惠方; 王希良

    2009-01-01

    To screen the potent adjuvants used in transcutaneous immunization with inactivated highly pathogenic avian influenza vaccine, four different adjuvants, CT, CpGODN1826, CpG ODN2006 and MF59, were used to immunize BALB/c mice together with this kind of vaccine in different proportions by transcutaneous immunization route and sera were collected before the first transcutaneous immunization and every two weeks post immunization. The titers of influenza virus-specific humoral IgG, and IgA were assayed in serum, lung and nasal lavages by ELISA. The titers of hemagglutination inhibition (HAD and IFN-7 and IL-4 produced by splenic lymphocytes were also detected. Our data showed that serum IgG titers and HAI titers in the groups of CpG1826 + HA, CT+HA and CpG1826 + CT+HA were significantly higher than those of HA group (P<0. 05) , particularly, in CpG1826 + CT+HA group. In addition, the influenza virus-specific IgA and IgG were detected in the lung and nasal lavages. Furthermore, the numbers of splenic lymphocytes producing IFN-γ and IL-4 were increased in mice after vaccination with inactivated highly pathogenic avian influenza combined with different adjuvants in comparison with those in control groups. Our result of study indicates that CpG ODN and cholera toxin are potent trancutaneous adjuvants in mouse model inoculated with inactivated high pathogenic avian influenza vaccine, and both of them can induce Th1 and Th2 cytokine production and mucosal immune responses.%用不同的佐剂与高致病性人禽流感H5N1全病毒疫苗混合,通过透皮途径免疫BALB/c小鼠并评价其免疫应答效果,从而初步筛选出较好的透皮免疫佐剂.实验选用CT、CPG 0DN1826、CpG ODN2006、MF59四种不同的佐剂按适当的比例与高致病性人禽流感H5N1灭活全病毒抗原混合制成透皮疫苗,透皮免疫BALB/c小鼠,检测血清IgG抗体效价、血清中和抗体效价,以及肺、鼻灌洗液中特异性IgG和IgA抗体效价,并对脾淋

  3. The primary research on mouse and cat infected with A/Tiger/Harbin/01/2003(H5N1)

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    It was confirmed by WHOthat the H5N1viruses resultedinsevere or fatal respiratory disease inthe majority of infectedpersons,indicatingthat the H5N1viruses had crossedthe species barrier without genetic reassortment with a humanin-fluenza virus.To design more effective strategies for prevention and treatment of H5N1viruses infected,in the presentstudy,we used atiger original HPAIVA/Tiger/Harbin/01/2003(H5N1)propagated by SPFembryonated hen eggs to es-tablishinfected animal model.TCID50of virus was10-8/0·1ml ...

  4. Associations between attributes of live poultry trade and HPAI H5N1 outbreaks: a descriptive and network analysis study in northern Vietnam

    Directory of Open Access Journals (Sweden)

    Otte Joachim

    2010-02-01

    Full Text Available Abstract Background The structure of contact between individuals plays an important role in the incursion and spread of contagious diseases in both human and animal populations. In the case of avian influenza, the movement of live birds is a well known risk factor for the geographic dissemination of the virus among poultry flocks. Live bird markets (LBM's contribute to the epidemiology of avian influenza due to their demographic characteristics and the presence of HPAI H5N1 virus lineages. The relationship between poultry producers and live poultry traders (LPT's that operate in LBM's has not been adequately documented in HPAI H5N1-affected SE Asian countries. The aims of this study were to document and study the flow of live poultry in a poultry trade network in northern Vietnam, and explore its potential role in the risk for HPAI H5N1 during 2003 to 2006. Results Our results indicate that LPT's trading for less than a year and operating at retail markets are more likely to source poultry from flocks located in communes with a past history of HPAI H5N1 outbreaks during 2003 to 2006 than LPT's trading longer than a year and operating at wholesale markets. The results of the network analysis indicate that LPT's tend to link communes of similar infection status. Conclusions Our study provides evidence which can be used for informing policies aimed at encouraging more biosecure practices of LPT's operating at authorised LBM's. The results suggest that LPT's play a role in HPAI H5N1 transmission and may contribute to perpetuating HPAI H5N1 virus circulation amongst certain groups of communes. The impact of current disease prevention and control interventions could be enhanced by disseminating information about outbreak risk and the implementation of a formal data recording scheme at LBM's for all incoming and outgoing LPT's.

  5. Investigation of Highly Pathogenic Avian Inlfuenza(H5N1) Outbreaks in Poultry in Ningxia, China, 2012%2012年宁夏H5N1亚型高致病性禽流感疫情回顾性调查

    Institute of Scientific and Technical Information of China (English)

    刘华雷; 黄保续; 王志亮; 王晓亮; Ricardo JSoares Magalhães; 李知新; 周小燕; 王静静; 赵云玲; 郑东霞; David Castellan

    2014-01-01

    chain reaction(RT-PCR) and confirmed by virus isolation. Multiple logistic regression analysis was used to identify the risk factors for infection and semivariogram analysis was used to demonstrate clustering of infected farms. Among 45 farms with positive PCR results,virus was isolated from four farms. Farms with improper waste disposal (adjusted OR = 2.7,95% CI = 1.20-8.30) and having visitors in farm within the past month(adjusted OR = 5.5, 95% CI = 1.97-15.64) were significantly associated with HPAI infection. Frequent human movement into farms and improper waste management increased the risk of infection. Biosecurity practices,including limiting number of visitors and proper waste disposal,should be enhanced to prevent further H5N1 infection.

  6. Purification of neuraminidase from Influenza virus subtype H5N1

    Directory of Open Access Journals (Sweden)

    Simson Tariga

    2009-03-01

    Full Text Available Influenza-virus neuraminidase plays vital role in the survival of the organisms. Vaccination of animals with this glycoprotein confers immune responses so that enable it to protect the animals from incoming infection. Supplementation of conventional vaccines with this glycoprotein increases the protection and longevity of the vaccine. Purified neuraminidase can also be used to develop serological tests for differentiation of serologically positive animals due to infection or to vaccination. In this study purification of neuraminidase from influenza virus subtype H5N1 was described. Triton x-100 and Octyl β-D-glucopyranoside were used to extract and diluted the glycoprotein membrane. The enzymatic activity of the neuraminidase was assayed using a fluorochrome substrate, 4-methylumbelliferyl-a-D-N-acetyl neuraminic acid, which was found to be simple, sensitive and suitable for the purification purpose. The neuraminidase was absorbed selectively on an oxamic-acid agarose column. The purity of neuraminidase eluted from this affinity column was high. A higher purity of the neuraminidase was obtained by further separation with gel filtration on Superdex-200. The purified neuraminidase was enzymatically active and did not contain any detectable haemagglutinin, either by haemagglutination assay or by monospecific antibodies raised against H5N1 hemagglutinin. The purified neuraminidase was recognized strongly by antibodies raised against an internal but only weakly by that against C-terminal regions of the neuraminidase protein of H5N1-influenza virus. The purified neuraminidase was in tetrameric forms but dissociated into monomeric form on reducing condition, or mostly dimeric form on non-reducing SDS-PAGE.

  7. In vitro assessment of attachment pattern and replication efficiency of H5N1 influenza A viruses with altered receptor specificity

    NARCIS (Netherlands)

    S. Chutinimitkul (Salin); D.A.J. van Riel (Debby); V.J. Munster (Vincent); J.M.A. van den Brand (Judith); G.F. Rimmelzwaan (Guus); T. Kuiken (Thijs); A.D.M.E. Osterhaus (Albert); R.A.M. Fouchier (Ron); E. de Wit (Emmie)

    2010-01-01

    textabstractThe continuous circulation of the highly pathogenic avian influenza (HPAI) H5N1 virus has been a cause of great concern. The possibility of this virus acquiring specificity for the human influenza A virus receptor, α2,6-linked sialic acids (SA), and being able to transmit efficiently amo

  8. Pulmonary immunization of chickens using non-adjuvanted spray-freeze dried whole inactivated virus vaccine completely protects against highly pathogenic H5N1 avian influenza virus

    NARCIS (Netherlands)

    Peeters, Ben; Tonnis, Wouter F; Murugappan, Senthil; Rottier, Peter; Koch, Guus; Frijlink, Henderik W; Huckriede, Anke; Hinrichs, Wouter L J

    2014-01-01

    Highly pathogenic avian influenza (HPAI) H5N1 virus is a major threat to public health as well as to the global poultry industry. Most fatal human infections are caused by contact with infected poultry. Therefore, preventing the virus from entering the poultry population is a priority. This is,

  9. Pulmonary immunization of chickens using non-adjuvanted spray-freeze dried whole inactivated virus vaccine completely protects against highly pathogenic H5N1 avian influenza virus

    NARCIS (Netherlands)

    Peeters, Ben; Tonnis, Wouter F; Murugappan, Senthil; Rottier, Peter; Koch, Guus; Frijlink, Henderik W; Huckriede, Anke; Hinrichs, Wouter L J

    2014-01-01

    Highly pathogenic avian influenza (HPAI) H5N1 virus is a major threat to public health as well as to the global poultry industry. Most fatal human infections are caused by contact with infected poultry. Therefore, preventing the virus from entering the poultry population is a priority. This is, howe

  10. Enhanced virulence of clade 2.3.2.1 highly pathogenic avian influenza A(H5N1) viruses in ferrets

    Science.gov (United States)

    Sporadic avian to human transmission of highly pathogenic avian influenza (HPAI) A (H5N1) viruses necessitates the analysis of currently circulating and evolving clades to assess their potential risk. Following the spread and sustained circulation of clade 2 viruses across multiple continents, num...

  11. Antigenic variation of clade 2.1 H5N1 virus is determined by a few amino acid substitutions immediately adjacent to the receptor binding site

    NARCIS (Netherlands)

    B.F. Koel (Björn); S. van der Vliet (Stefan); D.F. Burke (David); T.M. Bestebroer (Theo); E.E. Bharoto (Eny); I.W.W. Yasa (I. Wayan); I. Herliana (Inna); B.M. Laksono (Brigitta); K. Xu (Kemin); E. Skepner (Eugene); C.A. Russell (Colin); G.F. Rimmelzwaan (Guus); D.R. Perez (Daniel); A.D.M.E. Osterhaus (Albert); D.J. Smith (Derek James); T.Y. Prajitno (Teguh); R.A.M. Fouchier (Ron)

    2014-01-01

    textabstractHighly pathogenic avian influenza (HPAI) viruses of the H5N1 subtype are genetically highly variable and have diversified into multiple phylogenetic clades over the past decade. Antigenic drift is a well-studied phenomenon for seasonal human influenza viruses, but much less is known abou

  12. D701N mutation in the PB2 protein contributes to the pathogenicity of H5N1 avian influenza viruses but not transmissibility in guinea pigs

    Directory of Open Access Journals (Sweden)

    Peirong eJiao

    2014-11-01

    Full Text Available H5N1 highly pathogenic avian influenza virus (HPAIV of clade 2.3.2 has been circulating in waterfowl in Southern China since 2003. Our previous studies showed that certain H5N1 HPAIV isolates within clade 2.3.2 from Southern China had high pathogenicity in different birds. Guinea pigs have been successfully used as models to evaluate the transmissibility of AIVs and other species of influenza viruses in mammalian hosts. However, few studies have reported pathogenicity and transmissibility of H5N1 HPAIVs of this clade in guinea pigs. In this study, we selected an H5N1 HPAIV isolate, A/duck/Guangdong/357/2008, to investigate the pathogenicity and transmissibility of the virus in guinea pigs. The virus had high pathogenicity in mice; additionally, it only replicated in some tissues of the guinea pigs without production of clinical signs, but was transmissible among guinea pigs. Interestingly, virus isolates from co-caged guinea pigs had the D701N mutation in the PB2 protein. These mutant viruses showed higher pathogenicity in mice and higher replication capability in guinea pigs but did not demonstrate enhanced the transmissibility among guinea pigs. These findings indicate the transmission of the H5N1 virus between mammals could induce virus mutations, and the mutant viruses might have higher pathogenicity in mammals without higher transmissibility. Therefore, the continued evaluation of the pathogenicity and transmissibility of avian influenza virus (AIVs in mammals is critical to the understanding of the evolutionary characteristics of AIVs and the emergence of potential pandemic strains.

  13. D701N mutation in the PB2 protein contributes to the pathogenicity of H5N1 avian influenza viruses but not transmissibility in guinea pigs.

    Science.gov (United States)

    Jiao, Peirong; Wei, Liangmeng; Song, Yafen; Cui, Jin; Song, Hui; Cao, Lan; Yuan, Runyu; Luo, Kaijian; Liao, Ming

    2014-01-01

    H5N1 highly pathogenic avian influenza virus (HPAIV) of clade 2.3.2 has been circulating in waterfowl in Southern China since 2003. Our previous studies showed that certain H5N1 HPAIV isolates within clade 2.3.2 from Southern China had high pathogenicity in different birds. Guinea pigs have been successfully used as models to evaluate the transmissibility of AIVs and other species of influenza viruses in mammalian hosts. However, few studies have reported pathogenicity and transmissibility of H5N1 HPAIVs of this clade in guinea pigs. In this study, we selected an H5N1 HPAIV isolate, A/duck/Guangdong/357/2008, to investigate the pathogenicity and transmissibility of the virus in guinea pigs. The virus had high pathogenicity in mice; additionally, it only replicated in some tissues of the guinea pigs without production of clinical signs, but was transmissible among guinea pigs. Interestingly, virus isolates from co-caged guinea pigs had the D701N mutation in the PB2 protein. These mutant viruses showed higher pathogenicity in mice and higher replication capability in guinea pigs but did not demonstrate enhanced the transmissibility among guinea pigs. These findings indicate the transmission of the H5N1 virus between mammals could induce virus mutations, and the mutant viruses might have higher pathogenicity in mammals without higher transmissibility. Therefore, the continued evaluation of the pathogenicity and transmissibility of avian influenza virus (AIVs) in mammals is critical to the understanding of the evolutionary characteristics of AIVs and the emergence of potential pandemic strains.

  14. Avian influenza H5N1 virus infections in vaccinated commercial and backyard poultry in Egypt.

    Science.gov (United States)

    Hafez, M H; Arafa, A; Abdelwhab, E M; Selim, A; Khoulosy, S G; Hassan, M K; Aly, M M

    2010-08-01

    In this paper, we describe results from a high-pathogenic H5N1 avian influenza virus (AIV) surveillance program in previously H5-vaccinated commercial and family-backyard poultry flocks that was conducted from 2007 to 2008 by the Egyptian National Laboratory for Veterinary Quality Control on Poultry Production. The real-time reverse transcription PCR assay was used to detect the influenza A virus matrix gene and detection of the H5 and N1 subtypes was accomplished using a commercially available kit real-time reverse transcription PCR assay. The virus was detected in 35/3,610 (0.97%) and 27/8,682 (0.31%) of examined commercial poultry farms and 246/816 (30%) and 89/1,723 (5.2%) of backyard flocks in 2007 and 2008, respectively. Positive flocks were identified throughout the year, with the highest frequencies occurring during the winter months. Anti-H5 serum antibody titers in selected commercial poultry ranged from poultry in Egypt to combat H5N1 AIV, continuous circulation of the virus in vaccinated commercial and backyard poultry was reported and the efficacy of the vaccination using a challenge model with the current circulating field virus should be revised.

  15. Application of Baculovirus Dual Expression System in the Prevention of H5N1 Avian Influenza Virus%H5N1亚型禽流感病毒HA基因杆状病毒双表达系统的构建及其在小鼠的免疫原性分析

    Institute of Scientific and Technical Information of China (English)

    樊惠英; 林文耀; 佟铁铸; 张杰; 叶昱; 靳立明; 张春雷; 廖明

    2013-01-01

    Avian influenza is one of the deadly infectious diseases of poultry, which influences the development of agricultural economy of China greatly. Highly pathogenic avian influenza (HPAI) virus like H5N1 can even break the species barrier and infect human, which may pose great threat to public health. Currently, inactivated vaccines are the main vaccine in preventing avian influenza, which may accelerate virus transmission if we can't get the virus completely inactivated. Therefore, we need safer and more effective vaccines. In this study, we constructed a recombi-nant baculovirus BV-G-H5N1-HA, expressing HA protein in mammalian cell and exhibiting HA protein on the surface of the viral envelope simultaneously. Animal experiment was conducted by vaccinating mice intramuscularly with BV-G-H5N1-HA, pc-H5N1-HA, AcMNPV WT (wild-type AcMNPV) and PBS, respectively, then the mice were challenged intranasally (i. n. ) with A/Chicken/Guangzhou/M/2008(H5N1). Results showed that BV-G-H5N1l-HA can induce higher concentrations of neutralizing antibody and HI antibody in the immune group, and provide a considerable protection rate of 91. 7%. All these data indicate that BV-G-H5N1-HA may be a novel vaccine candidate which helps to prevent and control of HPAI in the future. Moreover, the application of novel baculovirus vector will provide important insights into the field of animal vaccine development.%高致病性禽流感严重制约着禽类产业链的健康发展,以H5N1为代表的高致病性禽流感病毒能够跨越种间障碍感染人,对公共卫生安全造成极大危害.而预防禽流感的传统疫苗主要是全病毒灭活苗,该类疫苗使用量大,灭活不全时易造成散毒,并给流行病学监测带来困难.研发更加安全、高效的新型疫苗势在必行.本研究选取H5N1亚型流感病毒的HA蛋白作为靶抗原,构建重组杆状病毒BV-G-H5N1-HA.重组病毒本身可刺激机体天然免疫反应,通过基因改造一方面能在真核

  16. Marked endotheliotropism of highly pathogenic avian influenza virus H5N1 following intestinal inoculation in cats

    NARCIS (Netherlands)

    L.A. Reperant (Leslie); M.W.G. van de Bildt (Marco); G. van Amerongen (Geert); L.M.E. Leijten (Lonneke); S. Watson (Sarah)

    2012-01-01

    textabstractHighly pathogenic avian influenza virus (HPAIV) H5N1 can infect mammals via the intestine; this is unusual since influenza viruses typically infect mammals via the respiratory tract. The dissemination of HPAIV H5N1 following intestinal entry and associated pathogenesis are largely unknow

  17. 75 FR 69046 - Notice of Determination of the High Pathogenic Avian Influenza Subtype H5N1 Status of Czech...

    Science.gov (United States)

    2010-11-10

    ... Pathogenic Avian Influenza Subtype H5N1 Status of Czech Republic and Sweden AGENCY: Animal and Plant Health... the highly pathogenic avian influenza (HPAI) subtype H5N1 status of the Czech Republic and Sweden... status of the Czech Republic and Sweden relative to highly pathogenic avian influenza (HPAI) subtype...

  18. Spatio-temporal magnitude and direction of highly pathogenic avian influenza (H5N1) outbreaks in Bangladesh

    DEFF Research Database (Denmark)

    Ahmed, Syed Sayeem Uddin; Ersbøll, Annette Kjær; Biswas, Paritosh K.;

    2011-01-01

    The number of outbreaks of HPAI-H5N1 reported by Bangladesh from 2007 through 2011 placed the country among the highest reported numbers worldwide. However, so far, the understanding of the epidemic progression, direction, intensity, persistence and risk variation of HPAI-H5N1 outbreaks over space...... and time in Bangladesh remains limited....

  19. Highly Pathogenic Avian Influenza H5N1 Clade 2.3.2.1c Virus in Lebanon, 2016.

    Science.gov (United States)

    El Romeh, Ali; Zecchin, Bianca; Fusaro, Alice; Ibrahim, Elias; El Bazzal, Bassel; El Hage, Jeanne; Milani, Adelaide; Zamperin, Gianpiero; Monne, Isabella

    2017-06-01

    We report the phylogenetic analysis of the first outbreak of H5N1 highly pathogenic avian influenza virus detected in Lebanon from poultry in April 2016. Our whole-genome sequencing analysis revealed that the Lebanese H5N1 virus belongs to genetic clade 2.3.2.1c and clusters with viruses from Europe and West Africa.

  20. Marked endotheliotropism of highly pathogenic avian influenza virus H5N1 following intestinal inoculation in cats

    NARCIS (Netherlands)

    Reperant, Leslie A; van de Bildt, Marco W G; van Amerongen, Geert; Leijten, Lonneke M E; Watson, Simon; Palser, Anne; Kellam, Paul; Eissens, Anko C; Frijlink, Hendrik W; Osterhaus, Albert D M E; Kuiken, Thijs; Frijlink, Henderik

    2012-01-01

    Highly pathogenic avian influenza virus (HPAIV) H5N1 can infect mammals via the intestine; this is unusual since influenza viruses typically infect mammals via the respiratory tract. The dissemination of HPAIV H5N1 following intestinal entry and associated pathogenesis are largely unknown. To assess

  1. Marked endotheliotropism of highly pathogenic avian influenza virus H5N1 following intestinal inoculation in cats

    NARCIS (Netherlands)

    L.A. Reperant (Leslie); M.W.G. van de Bildt (Marco); G. van Amerongen (Geert); L.M.E. Leijten (Lonneke); S. Watson (Sarah)

    2012-01-01

    textabstractHighly pathogenic avian influenza virus (HPAIV) H5N1 can infect mammals via the intestine; this is unusual since influenza viruses typically infect mammals via the respiratory tract. The dissemination of HPAIV H5N1 following intestinal entry and associated pathogenesis are largely

  2. Spatio-temporal magnitude and direction of highly pathogenic avian influenza (H5N1) outbreaks in Bangladesh

    DEFF Research Database (Denmark)

    Ahmed, Syed Sayeem Uddin; Ersbøll, Annette Kjær; Biswas, Paritosh K.

    2011-01-01

    The number of outbreaks of HPAI-H5N1 reported by Bangladesh from 2007 through 2011 placed the country among the highest reported numbers worldwide. However, so far, the understanding of the epidemic progression, direction, intensity, persistence and risk variation of HPAI-H5N1 outbreaks over spac...

  3. Prediction of a common neutralizing epitope of H5N1 avian influenza virus by in silico molecular docking

    Institute of Scientific and Technical Information of China (English)

    YAN YuanQing; XIA NingShao; LI ShaoWei; YANG ChunYan; LUO WenXin; WANG MingQiao; CHEN YiXin; LUO HaiFeng; WU Ting; ZHANG Jun

    2008-01-01

    The H5N1 avian influenza virus (AIV) has widely spread in Asia, Europe and Africa, making a large amount of economic loss. Recently, our research group has screened a common neutralizing mono-clonal antibody named 8H5, which can neutralize almost all H5 subtype AIV ever isolated so far. Obvi-ously, this monoclonal antibody would benefit for research and development of the universal AIV vac-cine and design of the drug against H5N1 AIV in high mutation rate. In this study, the homology mod-eling was applied to generate the 3D structure of 8H5 Fab fragment, and "canonical structure" method was used to define the specified loop conformation of CDR regions. The model was subjected to en-ergy minimization in cvff force field with Discovery module in Insight Ⅱ program. The resulting model has correct stereochemistry as gauged from the Ramachandran plot calculation and good 3D-structure compatibility as assessed by interaction energy analysis, solvent accessible surface (SAS) analysis, and Profiles-3D approach. Furthermore, the 8H5 Fab model was subjected to docking with three H5 subtype hemagglutinin (HA) structures deposited in PDB (ID No: 1jsm, 2ibx and 2fk0) respectively. The result indicates that the three docked complexes share a common binding interface, but differ in bind-ing angle related with HA structure similarity between viral subtypes. In the light of the three HA inter-faces with structural homology analysis, the common neutralizing epitope on HA recognized by 8H5 consists of 9 incontinuous amino acid residues: Asp68, Asn72, Glu112, Lys113, Ile114, Pro118, Ser120, Tyr137, Tyr252 (numbered as for 1jsm sequence), The primary purpose of the present work is to provide some insight into structure and binding details of a common neutralizing epitope of H5N1 AIV, thereby aiding in the structure-based design of universal AIV vaccines and anti-virus therapeutic drugs.

  4. Highly pathogenic avian influenza H5N1 Clade 2.3.2.1c virus in migratory birds, 2014-2015.

    Science.gov (United States)

    Bi, Yuhai; Chen, Jianjun; Zhang, Zhenjie; Li, Mingxin; Cai, Tianlong; Sharshov, Kirill; Susloparov, Ivan; Shestopalov, Alexander; Wong, Gary; He, Yubang; Xing, Zhi; Sun, Jianqing; Liu, Di; Liu, Yingxia; Liu, Lei; Liu, Wenjun; Lei, Fumin; Shi, Weifeng; Gao, George F

    2016-08-01

    A novel Clade 2.3.2.1c H5N1 reassortant virus caused several outbreaks in wild birds in some regions of China from late 2014 to 2015. Based on the genetic and phylogenetic analyses, the viruses possess a stable gene constellation with a Clade 2.3.2.1c HA, a H9N2-derived PB2 gene and the other six genes of Asian H5N1-origin. The Clade 2.3.2.1c H5N1 reassortants displayed a high genetic relationship to a human H5N1 strain (A/Alberta/01/2014). Further analysis showed that similar viruses have been circulating in wild birds in China, Russia, Dubai (Western Asia), Bulgaria and Romania (Europe), as well as domestic poultry in some regions of Africa. The affected areas include the Central Asian, East Asian-Australasian, West Asian-East African, and Black Sea/Mediterranean flyways. These results show that the novel Clade 2.3.2.1c reassortant viruses are circulating worldwide and may have gained a selective advantage in migratory birds, thus posing a serious threat to wild birds and potentially humans.

  5. Evaluating the Impact of Environmental Temperature on Global Highly Pathogenic Avian Influenza (HPAI H5N1 Outbreaks in Domestic Poultry

    Directory of Open Access Journals (Sweden)

    Zhijie Zhang

    2014-06-01

    Full Text Available The emergence and spread of highly pathogenic avian influenza (HPAI A virus subtype H5N1 in Asia, Europe and Africa has had an enormously socioeconomic impact and presents an important threat to human health because of its efficient animal-to-human transmission. Many factors contribute to the occurrence and transmission of HPAI H5N1 virus, but the role of environmental temperature remains poorly understood. Based on an approach of integrating a Bayesian Cox proportional hazards model and a Besag-York-Mollié (BYM model, we examined the specific impact of environmental temperature on HPAI H5N1 outbreaks in domestic poultry around the globe during the period from 1 December 2003 to 31 December 2009. The results showed that higher environmental temperature was a significant risk factor for earlier occurrence of HPAI H5N1 outbreaks in domestic poultry, especially for a temperature of 25 °C. Its impact varied with epidemic waves (EWs, and the magnitude of the impact tended to increase over EWs.

  6. Potential infections of H5N1 and H9N2 avian influenza do exist in Guangdong populations of China

    Institute of Scientific and Technical Information of China (English)

    LU Ci-yong; LU Jia-hai; CHEN Wei-qing; JIANG Li-fang; TAN Bing-yan; LING Wen-hua; ZHENG Bo-jian; SUI Hong-yan

    2008-01-01

    Background Southeast China is one of the sites of influenza origin. During 2003-2004, nine avian influenza outbreaks took place in Guangdong Province. But no human case was reported. To examine the status of potential human infection by human influenza (H1N1, H3N2) and avian influenza (H5N1, H7N7, H9N2) in the avian influenza epidemic area of Guangdong Province, China, we conducted a seroepidemiologic survey in the people of this area from April to June of 2004.Methods Three out of 9 H5N1 avian influenza affected poultry areas in Guangdong were randomly selected, and the population living within 3 kilometers of the affected poultries were chosen as the survey subjects. One thousand two hundred and fourteen people were selected from 3 villages at random. Human and avian influenza antibody tilers were determined by hemagglutination-inhibition (HI) test and microneutralization test (MNT).Results The positive rate of antibody to H5N1 was 3.03% in the occupational exposure group and 2.34% in general citizens group; that of H9N2 was 9.52% in the occupational exposure group and 3.76% in the general citizens group. Moreover one case in the occupational exposure group was positive for H7N7. One year later, all previously positive cases had become negative except for one H5N1 -positive case.Conclusion The observations imply that H5N1 and H9N2 avian influenza silent infections exist in Guangdon gpopulations.

  7. Development of Disease-specific, Context-specific Surveillance Models: Avian Influenza (H5N1)-Related Risks and Behaviours in African Countries.

    Science.gov (United States)

    Fasina, F O; Njage, P M K; Ali, A M M; Yilma, J M; Bwala, D G; Rivas, A L; Stegeman, A J

    2016-02-01

    Avian influenza virus (H5N1) is a rapidly disseminating infection that affects poultry and, potentially, humans. Because the avian virus has already adapted to several mammalian species, decreasing the rate of avian-mammalian contacts is critical to diminish the chances of a total adaptation of H5N1 to humans. To prevent the pandemic such adaptation could facilitate, a biology-specific disease surveillance model is needed, which should also consider geographical and socio-cultural factors. Here, we conceptualized a surveillance model meant to capture H5N1-related biological and cultural aspects, which included food processing, trade and cooking-related practices, as well as incentives (or disincentives) for desirable behaviours. This proof of concept was tested with data collected from 378 Egyptian and Nigerian sites (local [backyard] producers/live bird markets/village abattoirs/commercial abattoirs and veterinary agencies). Findings revealed numerous opportunities for pathogens to disseminate, as well as lack of incentives to adopt preventive measures, and factors that promoted epidemic dissemination. Supporting such observations, the estimated risk for H5N1-related human mortality was higher than previously reported. The need for multidimensional disease surveillance models, which may detect risks at higher levels than models that only measure one factor or outcome, was supported. To develop efficient surveillance systems, interactions should be captured, which include but exceed biological factors. This low-cost and easily implementable model, if conducted over time, may identify focal instances where tailored policies may diminish both endemicity and the total adaptation of H5N1 to the human species.

  8. Heterosubtype neutralizing responses to influenza A (H5N1 viruses are mediated by antibodies to virus haemagglutinin.

    Directory of Open Access Journals (Sweden)

    Jean-Michel Garcia

    Full Text Available BACKGROUND: It is increasingly clear that influenza A infection induces cross-subtype neutralizing antibodies that may potentially confer protection against zoonotic infections. It is unclear whether this is mediated by antibodies to the neuraminidase (NA or haemagglutinin (HA. We use pseudoviral particles (H5pp coated with H5 haemagglutinin but not N1 neuraminidase to address this question. In this study, we investigate whether cross-neutralizing antibodies in persons unexposed to H5N1 is reactive to the H5 haemagglutinin. METHODOLOGY/PRINCIPAL FINDINGS: We measured H5-neutralization antibody titers pre- and post-vaccination using the H5N1 micro-neutralization test (MN and H5pp tests in subjects given seasonal vaccines and in selected sera from European elderly volunteers in a H5N1 vaccine trial who had detectable pre-vaccination H5N1 MN antibody titers. We found detectable (titer > or = 20 H5N1 neutralizing antibodies in a minority of pre-seasonal vaccine sera and evidence of a serological response to H5N1 in others after seasonal influenza vaccination. There was excellent correlation in the antibody titers between the H5N1 MN and H5pp tests. Similar correlations were found between MN and H5pp in the pre-vaccine sera from the cohort of H5N1 vaccine trial recipients. CONCLUSIONS/SIGNIFICANCE: Heterosubtype neutralizing antibody to H5N1 in healthy volunteers unexposed to H5N1 is mediated by cross-reaction to the H5 haemagglutinin.

  9. Vectors based on modified vaccinia Ankara expressing influenza H5N1 hemagglutinin induce substantial cross-clade protective immunity.

    Directory of Open Access Journals (Sweden)

    Annett Hessel

    Full Text Available BACKGROUND: New highly pathogenic H5N1 influenza viruses are continuing to evolve with a potential threat for an influenza pandemic. So far, the H5N1 influenza viruses have not widely circulated in humans and therefore constitute a high risk for the non immune population. The aim of this study was to evaluate the cross-protective potential of the hemagglutinins of five H5N1 strains of divergent clades using a live attenuated modified vaccinia Ankara (MVA vector vaccine. METHODOLOGY/PRINCIPAL FINDINGS: The replication-deficient MVA virus was used to express influenza hemagglutinin (HA proteins. Specifically, recombinant MVA viruses expressing the HA genes of the clade 1 virus A/Vietnam/1203/2004 (VN/1203, the clade 2.1.3 virus A/Indonesia/5/2005 (IN5/05, the clade 2.2 viruses A/turkey/Turkey/1/2005 (TT01/05 and A/chicken/Egypt/3/2006 (CE/06, and the clade 2.3.4 virus A/Anhui/1/2005 (AH1/05 were constructed. These experimental live vaccines were assessed in a lethal mouse model. Mice vaccinated with the VN/1203 hemagglutinin-expressing MVA induced excellent protection against all the above mentioned clades. Also mice vaccinated with the IN5/05 HA expressing MVA induced substantial protection against homologous and heterologous AH1/05 challenge. After vaccination with the CE/06 HA expressing MVA, mice were fully protected against clade 2.2 challenge and partially protected against challenge of other clades. Mice vaccinated with AH1/05 HA expressing MVA vectors were only partially protected against homologous and heterologous challenge. The live vaccines induced substantial amounts of neutralizing antibodies, mainly directed against the homologous challenge virus, and high levels of HA-specific IFN-γ secreting CD4 and CD8 T-cells against epitopes conserved among the H5 clades and subclades. CONCLUSIONS/SIGNIFICANCE: The highest level of cross-protection was induced by the HA derived from the VN/1203 strain, suggesting that pandemic H5 vaccines

  10. A rapid Flp-In system for expression of secreted H5N1 influenza hemagglutinin vaccine immunogen in mammalian cells.

    Directory of Open Access Journals (Sweden)

    Hanxin Lu

    Full Text Available BACKGROUND: Continuing transmissions of highly pathogenic H5N1 viruses in poultry and humans underscores the need for a rapid response to potential pandemic in the form of vaccine. Recombinant technologies for production of immunogenic hemagglutinin (HA could provide an advantage over the traditional inactivated vaccine manufacturing process. Generation of stably transfected mammalian cells secreting properly folded HA proteins is important for scalable controlled manufacturing. METHODOLOGY/PRINCIPAL FINDINGS: We have developed a Flp-In based 293 stable cell lines through targeted site-specific recombination for expression of secreted hemagglutinin (HA proteins and evaluated their immunogenicity. H5N1 globular domain HA1(1-330 and HA0(1-500 proteins were purified from the supernatants of 293 Flp-In stable cell lines. Both proteins were properly folded as confirmed by binding to H5N1-neutralizing conformation-dependent human monoclonal antibodies. The HA0 (with unmodified cleavage site was monomeric, while the HA1 contained oligomeric forms. Upon rabbit immunization, both HA proteins elicited neutralizing antibodies against the homologous virus (A/Vietnam/1203/2004, clade 1 as well as cross-neutralizing antibodies against heterologous H5N1 clade 2 strains, including A/Indonesia/5/2005. These results exceeded the human antibody responses against the inactivated sub-virion H5N1 vaccine. CONCLUSIONS/SIGNIFICANCE: Our data suggest that the 293 Flp-In system could serve as a platform for rapid expression of HA immunogens in mammalian cells from emerging influenza strains.

  11. Movements of wild ruddy shelducks in the Central Asian Flyway and their spatial relationship to outbreaks of highly pathogenic avian influenza H5N1

    Science.gov (United States)

    Takekawa, John Y.; Prosser, Diann J.; Collins, Bridget M.; Douglas, David C.; Perry, William M.; Baoping, Yan; Luo, Ze; Hou, Yuansheng; Lei, Fumin; Li, Tianxian; Li, Yongdong; Newman, Scott H.

    2013-01-01

    Highly pathogenic avian influenza H5N1 remains a serious concern for both poultry and human health. Wild waterfowl are considered to be the reservoir for low pathogenic avian influenza viruses; however, relatively little is known about their movement ecology in regions where HPAI H5N1 outbreaks regularly occur. We studied movements of the ruddy shelduck (Tadorna ferruginea), a wild migratory waterfowl species that was infected in the 2005 Qinghai Lake outbreak. We defined their migration with Brownian Bridge utilization distribution models and their breeding and wintering grounds with fixed kernel home ranges. We correlated their movements with HPAI H5N1 outbreaks, poultry density, land cover, and latitude in the Central Asian Flyway. Our Akaike Information Criterion analysis indicated that outbreaks were correlated with land cover, latitude, and poultry density. Although shelduck movements were included in the top two models, they were not a top parameter selected in AICc stepwise regression results. However, timing of outbreaks suggested that outbreaks in the flyway began during the winter in poultry with spillover to wild birds during the spring migration. Thus, studies of the movement ecology of wild birds in areas with persistent HPAI H5N1 outbreaks may contribute to understanding their role in transmission of this disease.

  12. DNA prime and virus-like particle boost from a single H5N1 strain elicits broadly neutralizing antibody responses against head region of H5 hemagglutinin.

    Science.gov (United States)

    Wang, Guiqin; Zhou, Fan; Buchy, Philippe; Zuo, Teng; Hu, Hongxing; Liu, Jingjing; Song, Yufeng; Ding, Heng; Tsai, Cheguo; Chen, Ze; Zhang, Linqi; Deubel, Vincent; Zhou, Paul

    2014-03-01

    Since 1996, highly pathogenic avian influenza (HPAI) H5N1 virus has presented a persistent threat to public health. Its high degree of genetic diversity also poses enormous challenges in developing effective vaccines. To search for vaccine regimens that could elicit broadly neutralizing antibody responses against diverse HPAI H5N1 strains, in the present study we tested H5 hemagglutinin (HA) from an A/Thailand/1(KAN)-1/2004 strain in a heterologous prime-boost vaccination. We demonstrated that priming mice with DNA and boosting with virus-like particle induced antibody responses that cross-neutralize all reported clades and subclades of HPAI H5N1 viruses and protect mice from high lethal dose HPAI H5N1 challenge in both active and passive immunizations. Unexpectedly, cross-divergent H5 neutralizing antibodies are directed to the HA head and block both attachment and postattachment of virus entry. Thus, we conclude that as a promising pan-H5 vaccine candidate this prime-boost regimen could be further developed in ferrets and in humans.

  13. Glycan masking of hemagglutinin for adenovirus vector and recombinant protein immunizations elicits broadly neutralizing antibodies against H5N1 avian influenza viruses.

    Directory of Open Access Journals (Sweden)

    Shih-Chang Lin

    Full Text Available The highly pathogenic avian influenza (HPAI H5N1 virus, a known trigger of diseases in poultry and humans, is perceived as a serious threat to public health. There is a clear need for a broadly protective H5N1 vaccine or vaccines for inducing neutralizing antibodies against multiple clades/subclades. We constructed single, double, and triple mutants of glycan-masked hemagglutiinin (HA antigens at residues 83, 127 and 138 (i.e., g83, g127, g138, g83+g127, g127+g138, g83+g138 and g83+g127+g138, and then obtained their corresponding HA-expressing adenovirus vectors and recombinant HA proteins using a prime-boost immunization strategy. Our results indicate that the glycan-masked g127+g138 double mutant induced more potent HA-inhibition, virus neutralization antibodies, cross-clade protection against heterologous H5N1 clades, correlated with the enhanced bindings to the receptor binding sites and the highly conserved stem region of HA. The immune refocusing stem-specific antibodies elicited by the glycan-masked H5HA g127+g138 and g83+g127+g138 mutants overlapped with broadly neutralizing epitopes of the CR6261 monoclonal antibody that neutralizes most group 1 subtypes. These findings may provide useful information in the development of a broadly protective H5N1 influenza vaccine.

  14. A critical HA1 neutralizing domain of H5N1 influenza in an optimal conformation induces strong cross-protection.

    Directory of Open Access Journals (Sweden)

    Lanying Du

    Full Text Available The highly pathogenic avian influenza (HPAI H5N1 viruses, especially the laboratory-generated H5N1 mutants, have demonstrated the potential to cross the species barrier and infect mammals and humans. Consequently, the design of an effective and safe anti-H5N1 vaccine is essential. We previously demonstrated that the full-length hemagglutinin 1 (HA1 could induce significant neutralizing antibody response and protection. Here, we intended to identify the critical neutralizing domain (CND in an optimal conformation that can elicit strong cross-neutralizing antibodies and protection against divergent H5N1 strains. We thus constructed six recombinant proteins covering different regions of HA1 of A/Anhui/1/2005(H5N1, each of which was fused with foldon (Fd and Fc of human IgG. We found that the critical fragment fused with Fd/Fc (HA-13-263-Fdc, H5 numbering that could elicit the strongest neutralizing antibody response is located in the N-terminal region of HA1 (residues 13-263, which covers the receptor-binding domain (RBD, residues 112-263. We then constructed three additional recombinants fused with Fd plus His tag (HA-13-263-Fd-His, Fc only (HA-13-263-Fc, and His tag only (HA-13-263-His, respectively. We found that the HA-13-263-Fdc, which formed an oligomeric conformation, induced the strongest neutralizing antibody response and cross-protection against challenges of two tested H5N1 virus strains covering clade 1: A/VietNam/1194/2004 (VN/1194 or clade 2.3.4: A/Shenzhen/406H/06 (SZ/406H, while HA-13-263-Fc dimer and HA-13-263-Fd-His trimer elicited higher neutralizing antibody response and protection than HA-13-263-His monomer. These results suggest that the oligomeric form of the CND containing the RBD can be further developed as an effective and safe vaccine for cross-protection against divergent strains of H5N1 viruses.

  15. H5N1禽流感文献计量与可视化分析%Metrology and visualized analysis of H5N1 virus:a research of literature

    Institute of Scientific and Technical Information of China (English)

    陈婷; 吴曙霞; 盛立; 刘伟; 刁天喜

    2015-01-01

    目的:对国内外H5N1禽流感研究文献进行文献计量及可视化知识图谱分析。方法基于Web of Knowledge文献数据平台(SCI),综合应用Bibexcel、VOSviewer和Pajek等软件,展示全球H5N1禽流感研究的主要领域和前沿。结果从文献分析结果来看,全球H5 N1禽流感研究从2005年开始持续多年处于高水平态势,美国在这一领域处于领先地位,中国紧随其后。结论 H5 N1禽流感文献计量可视化分析显示,全球多国科学家常年都十分重视H5 N1禽流感研究,美国H5 N1禽流感研究整体实力最强,我国与国际相关研究机构还有一定差距,因此,应加强H5 N1禽流感研究,提高我国H5 N1禽流感研究整体实力水平,为应对可能发生的公共卫生突发事件提供必要的保障。%Objective To analyze domestic and foreign papers on H5N1 virus research using literature metrology and visualized knowledge mapping.Methods Pajek, Bibexcel,and VoSviewer software were used based on Web of Knowledge platform.Results Study on H5N1 virus has been a research focus wide since 2005 and a series of institutions and investi-gators have appeared, with US being the leader in this area and followed by China.The most popular topics of studies on H5N1 included its virology, epidemiology, basic research, anti-virus drugs and vaccines.Conclusion Studies on H5N1 have received more attention, which suggests that more efforts have to be made in China in terms of communication and co-operation with key institutions and famous researchers so as to achieve more success in key areas.

  16. Metapopulation dynamics and determinants of H5N1 highly pathogenic avian influenza outbreaks in Indonesian poultry.

    Science.gov (United States)

    Farnsworth, Matthew L; Fitchett, Stephanie; Hidayat, Muhammad Muharram; Lockhart, Caryl; Hamilton-West, Christopher; Brum, Eric; Angus, Stephen; Poermadjaja, Bagoes; Pinto, Julio

    2011-12-01

    In 2008, the Indonesian Government implemented a revised village-level Participatory Disease Surveillance and Response (PDSR) program to gain a better understanding of both the magnitude and spatial distribution of H5N1 highly pathogenic avian influenza (HPAI) outbreaks in backyard poultry. To date, there has been considerable collection of data, but limited publically available analysis. This study utilizes data collected by the PDSR program between April 2008 and September 2010 for Java, Bali and the Lampung Province of Sumatra. The analysis employs hierarchical Bayesian occurrence models to quantify spatial and temporal dynamics in backyard HPAI infection reports at the District level in 90 day time periods, and relates the probability of HPAI occurrence to PDSR-reported village HPAI infection status and human and poultry density. The probability of infection in a District was assumed to be dependent on the status of the District in the previous 90 day time period, and described by either a colonization probability (the probability of HPAI infection in a District given there had not been infection in the previous 90 day time period) or a persistence probability (the probability of HPAI infection being maintained in the District from the previous to current 90 day period). Results suggest that the number of surveillance activities in a district had little relationship to outbreak occurrence probabilities, but human and poultry densities were found to have non-linear relationships to outbreak occurrence probabilities. We found significant spatial dependency among neighboring districts, indicating that there are latent spatial processes that are not captured by the covariates available for this study, but which nonetheless impact outbreak dynamics. The results of this work may help improve understanding of the seasonal nature of H5N1 in poultry and the potential role of poultry density in enabling endemicity to occur, as well as to assist the Government of

  17. Smartphone-Based Fluorescent Diagnostic System for Highly Pathogenic H5N1 Viruses.

    Science.gov (United States)

    Yeo, Seon-Ju; Choi, Kyunghan; Cuc, Bui Thi; Hong, Nguyen Ngoc; Bao, Duong Tuan; Ngoc, Nguyen Minh; Le, Mai Quynh; Hang, Nguyen Le Khanh; Thach, Nguyen Co; Mallik, Shyam Kumar; Kim, Hak Sung; Chong, Chom-Kyu; Choi, Hak Soo; Sung, Haan Woo; Yu, Kyoungsik; Park, Hyun

    2016-01-01

    Field diagnostic tools for avian influenza (AI) are indispensable for the prevention and controlled management of highly pathogenic AI-related diseases. More accurate, faster and networked on-site monitoring is demanded to detect such AI viruses with high sensitivity as well as to maintain up-to-date information about their geographical transmission. In this work, we assessed the clinical and field-level performance of a smartphone-based fluorescent diagnostic device with an efficient reflective light collection module using a coumarin-derived dendrimer-based fluorescent lateral flow immunoassay. By application of an optimized bioconjugate, a smartphone-based diagnostic device had a two-fold higher detectability as compared to that of the table-top fluorescence strip reader for three different AI subtypes (H5N3, H7N1, and H9N2). Additionally, in a clinical study of H5N1-confirmed patients, the smartphone-based diagnostic device showed a sensitivity of 96.55% (28/29) [95% confidence interval (CI): 82.24 to 99.91] and a specificity of 98.55% (68/69) (95% CI: 92.19 to 99.96). The measurement results from the distributed individual smartphones were wirelessly transmitted via short messaging service and collected by a centralized database system for further information processing and data mining. Smartphone-based diagnosis provided highly sensitive measurement results for H5N1 detection within 15 minutes. Because of its high sensitivity, portability and automatic reporting feature, the proposed device will enable agile identification of patients and efficient control of AI dissemination.

  18. Induction of long-term protective immune responses by influenza H5N1 virus-like particles.

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    Sang-Moo Kang

    Full Text Available BACKGROUND: Recurrent outbreaks of highly pathogenic H5N1 avian influenza virus pose a threat of eventually causing a pandemic. Early vaccination of the population would be the single most effective measure for the control of an emerging influenza pandemic. METHODOLOGY/PRINCIPAL FINDINGS: Influenza virus-like particles (VLPs produced in insect cell-culture substrates do not depend on the availability of fertile eggs for vaccine manufacturing. We produced VLPs containing influenza A/Viet Nam1203/04 (H5N1 hemagglutinin, neuraminidase, and matrix proteins, and investigated their preclinical immunogenicity and protective efficacy. Mice immunized intranasally with H5N1 VLPs developed high levels of H5N1 specific antibodies and were 100% protected against a high dose of homologous H5N1 virus infection at 30 weeks after immunization. Protection is likely to be correlated with humoral and cellular immunologic memory at systemic and mucosal sites as evidenced by rapid anamnestic responses to re-stimulation with viral antigen in vivo and in vitro. CONCLUSIONS/SIGNIFICANCE: These results provide support for clinical evaluation of H5N1 VLP vaccination as a public health intervention to mitigate a possible pandemic of H5N1 influenza.

  19. Evidence for the Convergence Model: The Emergence of Highly Pathogenic Avian Influenza (H5N1) in Viet Nam.

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    Saksena, Sumeet; Fox, Jefferson; Epprecht, Michael; Tran, Chinh C; Nong, Duong H; Spencer, James H; Nguyen, Lam; Finucane, Melissa L; Tran, Vien D; Wilcox, Bruce A

    2015-01-01

    Building on a series of ground breaking reviews that first defined and drew attention to emerging infectious diseases (EID), the 'convergence model' was proposed to explain the multifactorial causality of disease emergence. The model broadly hypothesizes disease emergence is driven by the co-incidence of genetic, physical environmental, ecological, and social factors. We developed and tested a model of the emergence of highly pathogenic avian influenza (HPAI) H5N1 based on suspected convergence factors that are mainly associated with land-use change. Building on previous geospatial statistical studies that identified natural and human risk factors associated with urbanization, we added new factors to test whether causal mechanisms and pathogenic landscapes could be more specifically identified. Our findings suggest that urbanization spatially combines risk factors to produce particular types of peri-urban landscapes with significantly higher HPAI H5N1 emergence risk. The work highlights that peri-urban areas of Viet Nam have higher levels of chicken densities, duck and geese flock size diversities, and fraction of land under rice or aquaculture than rural and urban areas. We also found that land-use diversity, a surrogate measure for potential mixing of host populations and other factors that likely influence viral transmission, significantly improves the model's predictability. Similarly, landscapes where intensive and extensive forms of poultry production overlap were found at greater risk. These results support the convergence hypothesis in general and demonstrate the potential to improve EID prevention and control by combing geospatial monitoring of these factors along with pathogen surveillance programs.

  20. Evidence for the Convergence Model: The Emergence of Highly Pathogenic Avian Influenza (H5N1 in Viet Nam.

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    Sumeet Saksena

    Full Text Available Building on a series of ground breaking reviews that first defined and drew attention to emerging infectious diseases (EID, the 'convergence model' was proposed to explain the multifactorial causality of disease emergence. The model broadly hypothesizes disease emergence is driven by the co-incidence of genetic, physical environmental, ecological, and social factors. We developed and tested a model of the emergence of highly pathogenic avian influenza (HPAI H5N1 based on suspected convergence factors that are mainly associated with land-use change. Building on previous geospatial statistical studies that identified natural and human risk factors associated with urbanization, we added new factors to test whether causal mechanisms and pathogenic landscapes could be more specifically identified. Our findings suggest that urbanization spatially combines risk factors to produce particular types of peri-urban landscapes with significantly higher HPAI H5N1 emergence risk. The work highlights that peri-urban areas of Viet Nam have higher levels of chicken densities, duck and geese flock size diversities, and fraction of land under rice or aquaculture than rural and urban areas. We also found that land-use diversity, a surrogate measure for potential mixing of host populations and other factors that likely influence viral transmission, significantly improves the model's predictability. Similarly, landscapes where intensive and extensive forms of poultry production overlap were found at greater risk. These results support the convergence hypothesis in general and demonstrate the potential to improve EID prevention and control by combing geospatial monitoring of these factors along with pathogen surveillance programs.

  1. Endotracheal Intubation Inoculation of H5N1 Virus and Detection of Virus in Organ Tissues in the Rhesus Macaques%气管插管法接种H5N1病毒感染恒河猴及系统组织病毒检测

    Institute of Scientific and Technical Information of China (English)

    吕琦; 邓巍; 鲍琳琳; 许黎黎; 李枫棣; 陈霆; 占玲俊; 秦川

    2011-01-01

    目的 测试气管插管法接种高致病性禽流感病毒H5N1感染恒河猴的优势效果及疾病分析,为有效感染恒河猴、制备H5N1疾病模型提供实验依据.方法 使用人源H5N1病毒液经气管插管滴入恒河猴上呼吸道进行感染,观察感染恒河猴的临床表现,每天采集咽拭子、鼻灌洗液,在感染前2d感染后第3、5、7天采血,感染后第3和7天分别解剖1只恒河猴,取支气管淋巴结、肠淋巴结、鼻甲、心、肝、脾、肺、肾、肠、气管、脑及血液进行病毒分离、核酸载量检测和血常规测定.结果 感染后第2天恒河猴出现食欲下降,活动减少,并伴有一过性体温升高,白细胞数和淋巴细胞数下降.咽拭子、鼻灌洗液、肺、心、气管、脑、肝、肾、肠和血液中都能分离到H5N1病毒.结论 气管插管法接种H5N1病毒能有效感染恒河猴,并在猴体内多组织中分离、检测到病毒,为制备完善的H5N1模型和检测指标确定、进一步研究H5N1病毒的致病机制等奠定了基础.%Objective To evaluate the feasibility of endotracheal intubation route in preparation of H5N1 virus infection in rhesus macaques and to obtain a more sensitive animal model. Methods The rhesus macaques were infected with H5N1 avian influenza virus by endotracheal intubation. Clinical signs were assessed daily, and throat swab, nasal wash , major organs and blood were collected for detection of virus load, isolation and blood routine analysis. Results After infection the animals exhibited anorexia, lethargy and transient fever, and the total number of circulating leukocytes and lymphocytes was decreased. Virus isolation, RT-PCR assay of the throat swabs, nasal washs materials showed that the intestine, lung, brain, spleen, kidney, heart and liver were the target of the virus replication and the virus could replicate in organs outside the lung. In addition, virus was also detected in the blood 3 days after infection

  2. Safety and immunogenicity of Sinovac’s prototype pandemic influenza H5N1 vaccines: a review on clinical trials

    OpenAIRE

    Qiu, Yuan‐Zheng; Yin, Wei‐Dong

    2008-01-01

    Abstract  Sinovac Biotech started to develop prototype pandemic influenza H5N1 vaccines in March 2004. On 2 April 2008, Sinovac’s inactivated, aluminium‐adjuvanted, whole‐virion prototype pandemic influenza A (H5N1) vaccine (PanFlu™) was granted production licensure by the China regulatory authority State Food and Drug Administration. The whole‐virion H5N1 vaccine was manufactured in embryonated hens’ eggs using the reassortant strain NIBRG‐14 (A/Vietnam/1194/2004‐A/PR/8/34) as vaccine virus....

  3. Protective measures and H5N1-seroprevalence among personnel tasked with bird collection during an outbreak of avian influenza A/H5N1 in wild birds, Ruegen, Germany, 2006

    OpenAIRE

    Littmann Martina; Buda Silke; Buchholz Udo; Schweiger Brunhilde; Cai Wei; Heusler Jörg; Haas Walter

    2009-01-01

    Background: In Germany, the first outbreak of highly pathogenic avian influenza A/H5N1 occurred among wild birds on the island of Ruegen between February and April 2006. The aim of this study was to investigate the use of recommended protective measures and to measure H5N1- seroprevalence among personnel tasked with bird collection. Methods: Inclusion criteria of our study were participation in collecting wild birds on Ruegen between February and March 2006. Study participants w...

  4. Broad Clade 2 cross-reactive immunity induced by an adjuvanted clade 1 rH5N1 pandemic influenza vaccine.

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    Isabel Leroux-Roels

    Full Text Available BACKGROUND: The availability of H5N1 vaccines that can elicit a broad cross-protective immunity against different currently circulating clade 2 H5N1 viruses is a pre-requisite for the development of a successful pre-pandemic vaccination strategy. In this regard, it has recently been shown that adjuvantation of a recombinant clade 1 H5N1 inactivated split-virion vaccine with an oil-in-water emulsion-based adjuvant system also promoted cross-immunity against a recent clade 2 H5N1 isolate (A/Indonesia/5/2005, subclade 2.1. Here we further analyse the cross-protective potential of the vaccine against two other recent clade 2 isolates (A/turkey/Turkey/1/2005 and A/Anhui/1/2005 which are, as defined by WHO, representatives of subclades 2.2 and 2.3 respectively. METHODS AND FINDINGS: Two doses of the recombinant A/Vietnam/1194/2004 (H5N1, clade 1 vaccine were administered 21 days apart to volunteers aged 18-60 years. We studied the cross-clade immunogenicity of the lowest antigen dose (3.8 microg haemagglutinin given with (N = 20 or without adjuvant (N = 20. Immune responses were assessed at 21 days following the first and second vaccine doses and at 6 months following first vaccination. Vaccination with two doses of 3.8 microg of the adjuvanted vaccine induced four-fold neutralising seroconversion rates in 85% of subjects against A/turkey/Turkey/1/2005 (subclade 2.2 and 75% of subjects against A/Anhui/1/2005 (subclade 2.3 recombinant strains. There was no response induced against these strains in the non-adjuvanted group. At 6 months following vaccination, 70% and 60% of subjects retained neutralising antibodies against the recombinant subclade 2.2 and 2.3 strains, respectively and 40% of subjects retained antibodies against the recombinant subclade 2.1 A/Indonesia/5/2005 strain. CONCLUSIONS: In addition to antigen dose-sparing, adjuvantation of inactivated split H5N1 vaccine promotes broad and persistent cross-clade immunity which is a pre

  5. Fluorescence biosensor based on CdTe quantum dots for specific detection of H5N1 avian influenza virus

    Science.gov (United States)

    Hoa Nguyen, Thi; Dieu Thuy Ung, Thi; Hien Vu, Thi; Tran, Thi Kim Chi; Quyen Dong, Van; Khang Dinh, Duy; Liem Nguyen, Quang

    2012-09-01

    This report highlights the fabrication of fluorescence biosensors based on CdTe quantum dots (QDs) for specific detection of H5N1 avian influenza virus. The core biosensor was composed of (i) the highly luminescent CdTe/CdS QDs, (ii) chromatophores extracted from bacteria Rhodospirillum rubrum, and (iii) the antibody of β-subunit. This core part was linked to the peripheral part of the biosensor via a biotin-streptavidin-biotin bridge and finally connected to the H5N1 antibody to make it ready for detecting H5N1 avian influenza virus. Detailed studies of each constituent were performed showing the image of QDs-labeled chromatophores under optical microscope, proper photoluminescence (PL) spectra of CdTe/CdS QDs, chromatophores and the H5N1 avian influenza viruses.

  6. VARIATION OF NON-CODING REGION AND CODING REGION OF 5’-TERMINAL CRNA OF POLYMERASE BASIC 1 OF AVIAN INFLUENZA VIRUS SUBTYPE H5N1

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    Gusti Ayu Yuniati Kencana

    2009-03-01

    Full Text Available The sequence of the Non-Coding Region (NCR and Coding Region (CR of 5’-terminal cRNA of thepolymerase basic 1 (PB1 gene as a major factor for the species adaptation of avian influenza virussubtype H5N1 (AIV H5N1 has been analysed. The information could be a virological signal for theemergence of a new strain with pandemic potential. Total RNA from twenty six (26 avian influenzasubtype H5N1 isolates were amplified using reverse-transcriptase-polymerase chain reaction (RT-PCRwith a universal forward primer for influenza virus and specifically designed backward primers. Fifteen(15 PB1 gene fragments could be amplified. RT-PCR products were sequenced and analyzed using Mega4software. The length of NCR of PB1 gene was found to be 24 bases and mostly shows conserved sequence,with an exception of Dk/Badung/2006 isolate which has C-7T substitution. A/T composition of PB1 NCRwas 54,2%, while the Dk/Badung/2006 isolate was 58,3%. Species and geographical specificity could not befound in the genetic distance, the amino acid polymorphism, as well as the phylogenetic analysis of t

  7. Rapid Emergence of Highly Pathogenic Avian Influenza Subtypes from a Subtype H5N1 Hemagglutinin Variant.

    Science.gov (United States)

    de Vries, Erik; Guo, Hongbo; Dai, Meiling; Rottier, Peter J M; van Kuppeveld, Frank J M; de Haan, Cornelis A M

    2015-05-01

    In 2014, novel highly pathogenic avian influenza A H5N2, H5N5, H5N6, and H5N8 viruses caused outbreaks in Asia, Europe, and North America. The H5 genes of these viruses form a monophyletic group that evolved from a clade 2.3.4 H5N1 variant. This rapid emergence of new H5Nx combinations is unprecedented in the H5N1 evolutionary history.

  8. Migration of whooper swans and outbreaks of highly pathogenic avian influenza H5N1 virus in Eastern Asia

    Science.gov (United States)

    Newman, Scott H.; Iverson, Samuel A.; Takekawa, John Y.; Gilbert, Martin; Prosser, Diann J.; Batbayar, Nyambyar; Natsagdorj, Tseveenmyadag; Douglas, David C.

    2009-01-01

    Evaluating the potential involvement of wild avifauna in the emergence of highly pathogenic avian influenza H5N1 (hereafter H5N1) requires detailed analyses of temporal and spatial relationships between wild bird movements and disease emergence. The death of wild swans (Cygnus spp.) has been the first indicator of the presence of H5N1 in various Asian and European countries; however their role in the geographic spread of the disease remains poorly understood. We marked 10 whooper swans (Cygnus cygnus) with GPS transmitters in northeastern Mongolia during autumn 2006 and tracked their migratory movements in relation to H5N1 outbreaks. The prevalence of H5N1 outbreaks among poultry in eastern Asia during 2003-2007 peaked during winter, concurrent with whooper swan movements into regions of high poultry density. However outbreaks involving poultry were detected year round, indicating disease perpetuation independent of migratory waterbird presence. In contrast, H5N1 outbreaks involving whooper swans, as well as other migratory waterbirds that succumbed to the disease in eastern Asia, tended to occur during seasons (late spring and summer) and in habitats (areas of natural vegetation) where their potential for contact with poultry is very low to nonexistent. Given what is known about the susceptibility of swans to H5N1, and on the basis of the chronology and rates of whooper swan migration movements, we conclude that although there is broad spatial overlap between whooper swan distributions and H5N1 outbreak locations in eastern Asia, the likelihood of direct transmission between these groups is extremely low. Thus, our data support the hypothesis that swans are best viewed as sentinel species, and moreover, that in eastern Asia, it is most likely that their infections occurred through contact with asymptomatic migratory hosts (e.g., wild ducks) at or near their breeding grounds.

  9. Progress toward a universal H5N1 vaccine: a recombinant modified vaccinia virus Ankara-expressing trivalent hemagglutinin vaccine.

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    Mookkan Prabakaran

    Full Text Available The rapid evolution of new sublineages of H5N1 influenza poses the greatest challenge in control of H5N1 infection by currently existing vaccines. To overcome this, an MVAtor vector expressing three H5HA antigens A/Vietnam/1203/04, A/Indonesia/669/06 and A/Anhui/01/05 (MVAtor-tri-HA vector was developed to elicit broad cross-protection against diverse clades by covering amino acid variations in the major neutralizing epitopes of HA among H5N1 subtypes.BALB/c mice and guinea pigs were immunized i.m. with 8×107 TCID50/animal of MVAtor-tri-HA vector. The immunogenicity and cross-protective immunity of the MVAtor-tri-HA vector was evaluated against diverse clades of H5N1 strains.The results showed that mice immunized with MVAtor-tri-HA vector induced robust cross-neutralizing immunity to diverse H5N1 clades. In addition, the MVAtor-tri-HA vector completely protected against 10 MLD50 of a divergent clade of H5N1 infection (clade 7. Importantly, the serological surveillance of post-vaccinated guinea pig sera demonstrated that MVAtor-tri-HA vector was able to elicit strong cross-clade neutralizing immunity against twenty different H5N1 strains from six clades that emerged between 1997 and 2012.The present findings revealed that incorporation of carefully selected HA genes from divergent H5N1 strains within a single vector could be an effective approach in developing a vaccine with broad coverage to prevent infection during a pandemic situation.

  10. Genetic Characterization of Clade 2.3.2.1 Avian Influenza A(H5N1) Viruses, Indonesia, 2012

    Science.gov (United States)

    Hartawan, Risza; Pudjiatmoko; Wibawa, Hendra; Hardiman; Balish, Amanda; Donis, Ruben; Davis, C. Todd; Samaan, Gina

    2014-01-01

    After reports of unusually high mortality rates among ducks on farms in Java Island, Indonesia, in September 2012, influenza A(H5N1) viruses were detected and characterized. Sequence analyses revealed all genes clustered with contemporary clade 2.3.2.1 viruses, rather than enzootic clade 2.1.3 viruses, indicating the introduction of an exotic H5N1 clade into Indonesia. PMID:24656213

  11. Outbreaks of avian influenza A (H5N2), (H5N8), and (H5N1) among birds--United States, December 2014-January 2015.

    Science.gov (United States)

    Jhung, Michael A; Nelson, Deborah I

    2015-02-06

    During December 15, 2014-January 16, 2015, the U.S. Department of Agriculture received 14 reports of birds infected with Asian-origin, highly pathogenic avian influenza A (HPAI) (H5N2), (H5N8), and (