WorldWideScience

Sample records for avian influenza h5n1

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Characterization of avian influenza H5N1 virosome

    Directory of Open Access Journals (Sweden)

    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.

  6. 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...

  7. 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.

  8. 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.

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

    Science.gov (United States)

    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.

  10. 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)...

  11. 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

  12. 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...

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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...

  4. 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...

  5. 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.

  6. 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 ...

  7. 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...

  8. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  10. 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.

  11. 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.

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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...

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

    Science.gov (United States)

    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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  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. 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.

  4. 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.

  5. 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

  6. 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.

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

    Science.gov (United States)

    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.

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

    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 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...

  9. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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.

  12. 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.

  13. 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...

  14. 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

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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.

  3. Microarray analysis following infection with highly pathogenic avian influenza H5N1 virus in naive and vaccinated SPF chickens

    Science.gov (United States)

    Avian influenza (AI) is a viral disease of poultry that remains a constant threat to commercial poultry throughout the world. Within the last few years, outbreaks of highly pathogenic avian influenza (HPAI) H5N1 have originated in Southeast Asia and spread to several European, Middle Eastern, and A...

  4. 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...

  5. 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.

  6. 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.

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    Cássio da Cunha Ibiapina

    2005-10-01

    Full Text Available Este estudo tem como objetivo rever a literatura sobre o vírus influenza A aviária (H5N1. O levantamento bibliográfico foi realizado nos bancos de dados eletrônicos Medline, MD Consult, HighWire, Medscape e Literatura Latinoamericana y del Caribe en Ciencias de la Salud (LILACS, Literatura Latinoamericana e do Caribe em Ciências da Saúde, e por pesquisa direta, referentes aos últimos dez anos. Foram selecionados 32 artigos originais abordando os surtos recentes de infecção por um subtipo de vírus influenza A aviária, o H5N1, em criações de aves domésticas na Ásia, que resultaram em importantes prejuízos econômicos e repercussões em saúde pública, além de casos de infecção humana de alta letalidade. A maioria dos casos está associada com a exposição direta a aves infectadas ou superfícies contaminadas com excrementos dessas aves, porém foi confirmada a transmissão entre humanos. O período de incubação foi de dois a quatro dias. As manifestações clínicas variaram de infecção assintomática e doença leve do trato respiratório superior a pneumonia grave e falência múltipla de órgãos. A radiografia de tórax pode apresentar infiltrado intersticial bilateral, colapso lobar, consolidação focal e broncograma aéreo sem derrame pleural. A presença de linfopenia indica pior prognóstico. O tratamento de suporte parece ser o único tratamento aceitável. Os fatores de risco para mau prognóstico incluem idade avançada, demora na hospitalização, envolvimento do trato respiratório inferior, baixa contagem de leucócitos totais e linfopenia à admissão. Controlar os surtos em aves domésticas e o contato entre seres humanos e tais aves deve ser a prioridade no manejo da doença em nível de saúde pública, e medidas e conhecimentos acerca da doença devem ser amplamente divulgados.The objective of this study was to review the literature related to avian influenza A (H5N1. The bibliographic research was

  9. 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.

  10. Radiological and clinical course of pneumonia in patients with avian influenza H5N1

    Energy Technology Data Exchange (ETDEWEB)

    Bay, Ali [Yuzuncu Yil University, Faculty of Medicine, Department of Pediatrics, Van (Turkey)]. E-mail: bayalibay@yahoo.com; Etlik, Omer [Yuzuncu Yil University, Faculty of Medicine, Department of Radiology, Van (Turkey); Oner, A. Faik [Yuzuncu Yil University, Faculty of Medicine, Department of Pediatrics, Van (Turkey); Unal, Ozkan [Yuzuncu Yil University, Faculty of Medicine, Department of Radiology, Van (Turkey); Arslan, Halil [Yuzuncu Yil University, Faculty of Medicine, Department of Radiology, Van (Turkey); Bora, Aydin [Yuzuncu Yil University, Faculty of Medicine, Department of Radiology, Van (Turkey); Davran, Ramazan [Yuzuncu Yil University, Faculty of Medicine, Department of Radiology, Van (Turkey); Yuca, Sevil Ari [Yuzuncu Yil University, Faculty of Medicine, Department of Pediatrics, Van (Turkey); Dogan, Murat [Yuzuncu Yil University, Faculty of Medicine, Department of Pediatrics, Van (Turkey)

    2007-02-15

    Introduction: We evaluated chest X-ray and clinical findings of patients with lower respiratory tract infection due to influenza H5N1 and presented the radiological findings and clinical course of the infection. Materials and methods: Between December 2005 and February 2006, eight hospitalized patients (median age 10, 5-15 years) with avian-flu were evaluated in this study. All patients were evaluated with chest X-ray and four of them with CT scan. Post mortem pathological characterization were also available for three of the patients. Results: A rapidly progressive pneumonia with high mortality rate was observed especially for cases with late admission. The major radiologic abnormalities were extensive pneumonic infiltration with segmental and multifocal distribution, mostly located in lower zones of the lung. No pleural effusion and hilar lymphadenopathy was noted. Conclusion: Avian flu may be presented as rapidly progressive pneumonia. The chest radiography has an important role in diagnosis and should be obtained daily because of rapid change of the findings that may necessitate prompt action.

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

    Directory of Open Access Journals (Sweden)

    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.

  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

    Directory of Open Access Journals (Sweden)

    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. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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.

  16. 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

  17. 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

  18. 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

  19. Maternal immunity against avian influenza H5N1 in chickens: limited protection and interference with vaccine efficacy

    NARCIS (Netherlands)

    Maas, H.A.; Rosema, S.; Zoelen-Bos, van D.J.; Kemper-Venema, S.

    2011-01-01

    After avian influenza (AI) vaccination, hens will produce progeny chickens with maternally derived AI-specific antibodies. In the present study we examined the effect of maternal immunity in young chickens on the protection against highly pathogenic AI H5N1 virus infection and on the effectiveness o

  20. 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...

  1. 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.

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

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    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.

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

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    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.

  4. 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.

  5. 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.

  6. 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

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

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    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

  8. Seroprevalence of antibodies against highly pathogenic avian influenza A (H5N1 virus among poultry workers in Bangladesh, 2009.

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    Sharifa Nasreen

    Full Text Available We conducted a cross-sectional study in 2009 to determine the seroprevalence and risk factors for highly pathogenic avian influenza A (H5N1 [HPAI H5N1] virus antibodies among poultry workers at farms and live bird markets with confirmed/suspected poultry outbreaks during 2009 in Bangladesh. We tested sera by microneutralization assay using A/Bangladesh/207095/2008 (H5N1; clade 2.2.2 virus with confirmation by horse red blood cell hemagglutination inhibition and H5-specific Western blot assays. We enrolled 212 workers from 87 farms and 210 workers from three live bird markets. One hundred and two farm workers (48% culled poultry. One hundred and ninety-three farm workers (91% and 178 market workers (85% reported direct contact with poultry that died during a laboratory confirmed HPAI H5N1 poultry farm outbreak or market poultry die-offs from suspected HPAI H5N1. Despite exposure to sick poultry, no farm or market poultry workers were seropositive for HPAI H5N1 virus antibodies (95% confidence interval 0-1%.

  9. 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

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

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    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.

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

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    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.

  13. 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.

  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. 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.

  16. 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

  17. 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

  18. 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.

  19. Comparative susceptibility of waterfowl and gulls to highly pathogenic avian influenza H5N1 virus

    Science.gov (United States)

    Wild avian species in the Orders Anseriformes (ducks, geese, swans) and Charadriiformes (gulls, terns, shorebirds) have traditionally been considered the natural reservoirs for avian influenza viruses (AIV) and morbidity or mortality is rarely associated with AIV infection in these hosts. However, ...

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

    Science.gov (United States)

    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.

  1. 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...

  2. 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.

  3. 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.

  4. Ecology and geography of avian influenza (HPAI H5N1 transmission in the Middle East and northeastern Africa

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    Peterson A Townsend

    2009-07-01

    Full Text Available Abstract Background The emerging highly pathogenic avian influenza strain H5N1 ("HPAI-H5N1" has spread broadly in the past decade, and is now the focus of considerable concern. We tested the hypothesis that spatial distributions of HPAI-H5N1 cases are related consistently and predictably to coarse-scale environmental features in the Middle East and northeastern Africa. We used ecological niche models to relate virus occurrences to 8 km resolution digital data layers summarizing parameters of monthly surface reflectance and landform. Predictive challenges included a variety of spatial stratification schemes in which models were challenged to predict case distributions in broadly unsampled areas. Results In almost all tests, HPAI-H5N1 cases were indeed occurring under predictable sets of environmental conditions, generally predicted absent from areas with low NDVI values and minimal seasonal variation, and present in areas with a broad range of and appreciable seasonal variation in NDVI values. Although we documented significant predictive ability of our models, even between our study region and West Africa, case occurrences in the Arabian Peninsula appear to follow a distinct environmental regime. Conclusion Overall, we documented a variable environmental "fingerprint" for areas suitable for HPAI-H5N1 transmission.

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

    Science.gov (United States)

    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.

  6. 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.

  7. Pathology of natural highly pathogenic avian influenza H5N1 infection in wild tufted ducks (Aythya fuligula).

    Science.gov (United States)

    Bröjer, Caroline; Agren, Erik O; Uhlhorn, Henrik; Bernodt, Karin; Mörner, Torsten; Jansson, Désirée S; Mattsson, Roland; Zohari, Siamak; Thorén, Peter; Berg, Mikael; Gavier-Widén, Dolores

    2009-09-01

    Highly pathogenic avian influenza (HPAI) subtype H5N1 is an infectious systemic viral disease that results in high morbidity and mortality in poultry, and has been reported in a wide range of wild bird species during the last few years. An outbreak of HPAI H5N1 occurred in wild birds in Sweden in 2006 that affected several duck species, geese, swans, gulls, and raptors. Tufted ducks (Aythya fuligula) accounted for the largest number of positive cases and, therefore, were selected for more in-depth histologic and immunohistochemical evaluations. The main histologic lesions associated with the presence of avian influenza antigen were found in the brain, pancreas, and upper respiratory tract. Other tissues in which influenza antigen was variably found included liver, lung, adrenal glands, kidneys, and peripheral nerve ganglia. The current study describes the pathology and viral tissue targeting of H5N1 by using histology, polymerase chain reaction, and immunohistochemistry, and highlights the range and variation in the presentation of the natural disease in tufted ducks.

  8. Phylogenetic analysis of Neuraminidase gene of avian influenza H5N1 subtype detected in Iran in 1390(2011

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    E Kord

    2013-09-01

    Background & aim: Among the various subtypes of avian influenza viruses, an H5N1 subtype virus with high pathogenicity is of great importance. The aim of this study was to determine the Phylogenetic analysis of neuraminidase gene of avian influenza virus subtype of the H5N1 in Iran in 1390. Methods: In this experimental study, two swab samples from chickens with suspected symptoms of avian influenza were tested by the World Health Organization recommendation. The neuraminidase gene of positive samples was amplified by RT-PCR technique. After sequencing the phylogenetic studies were analyzed using MEGA5 and Megalign. Results: Phylogenetic analysis showed that the virus belongs to the Clade 2.3.2.1 which is highly similar to the viruses that are identified in Mongolia in 2010. Also in the stem of this virus neuraminidase protein a number of 20 amino acid has been deleted at position 69-49. Conclusion: Due to findings of this study, it seems that the virus has entered by migratory wild birds with the origin of Mongolia. Key words: Influenza, Avian, Neuraminidase

  9. 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.

  10. 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.

  11. 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.

  12. Victims and vectors: highly pathogenic avian influenza H5N1 and the ecology of wild birds

    Science.gov (United States)

    Takekawa, John Y.; Prosser, Diann J.; Newman, Scott H.; Muzaffar, Sabir Bin; Hill, Nichola J.; Yan, Baoping; Xiao, Xiangming; Lei, Fumin; Li, Tianxian; Schwarzbach, Steven E.; Howell, Judd A.

    2010-01-01

    The emergence of highly pathogenic avian influenza (HPAI) viruses has raised concerns about the role of wild birds in the spread and persistence of the disease. In 2005, an outbreak of the highly pathogenic subtype H5N1 killed more than 6,000 wild waterbirds at Qinghai Lake, China. Outbreaks have continued to periodically occur in wild birds at Qinghai Lake and elsewhere in Central China and Mongolia. This region has few poultry but is a major migration and breeding area for waterbirds in the Central Asian Flyway, although relatively little is known about migratory movements of different species and connectivity of their wetland habitats. The scientific debate has focused on the role of waterbirds in the epidemiology, maintenance and spread of HPAI H5N1: to what extent are they victims affected by the disease, or vectors that have a role in disease transmission? In this review, we summarise the current knowledge of wild bird involvement in the ecology of HPAI H5N1. Specifically, we present details on: (1) origin of HPAI H5N1; (2) waterbirds as LPAI reservoirs and evolution into HPAI; (3) the role of waterbirds in virus spread and persistence; (4) key biogeographic regions of outbreak; and (5) applying an ecological research perspective to studying AIVs in wild waterbirds and their ecosystems.

  13. 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.

  14. 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.

  15. 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.

  16. Living with avian FLU--Persistence of the H5N1 highly pathogenic avian influenza virus in Egypt.

    Science.gov (United States)

    Njabo, Kevin Yana; Zanontian, Linda; Sheta, Basma N; Samy, Ahmed; Galal, Shereen; Schoenberg, Frederic Paik; Smith, Thomas B

    2016-05-01

    H5N1 highly pathogenic avian influenza virus (HPAIV) continues to cause mortality in poultry and threaten human health at a panzootic scale in Egypt since it was reported in 2006. While the early focus has been in Asia, recent evidence suggests that Egypt is an emerging epicenter for the disease. Despite control measures, epizootic transmission of the disease continues. Here, we investigate the persistence of HPAIV across wild passerine birds and domestic poultry between 2009 and 2012 and the potential risk for continuous viral transmission in Egypt. We use a new weighted cross J-function to investigate the degree and spatial temporal nature of the clustering between sightings of infected birds of different types, and the risk of infection associated with direct contact with infected birds. While we found no infection in wild birds, outbreaks occurred year round between 2009 and 2012, with a positive interaction between chickens and ducks. The disease was more present in the years 2010 and 2011 coinciding with the political unrest in the country. Egypt thus continues to experience endemic outbreaks of avian influenza HPAIV in poultry and an increased potential risk of infection to other species including humans. With the current trends, the elimination of the HPAIV infection is highly unlikely without a complete revamp of current policies. The application of spatial statistics techniques to these types of data may help us to understand the characteristics of the disease and may subsequently allow practitioners to explore possible preventive solutions.

  17. 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.

  18. 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.

  19. Preparasi Imunoglobulin G Kelinci sebagai Antigen Penginduksi Antibodi Spesifik Terhadap Virus Avian Influenza H5N1 Strain Legok

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    Ketut Karuni Nyanakumari Natih

    2010-06-01

    Full Text Available The aim of this research was to prepare rabbit Immunoglobulin G as anti-idiotype antibody (Ab2 ofAvian Influenza Virus (AIV H5N1. A polyclonal antibody was collected from guinea pigs immunized withinactivated AI vaccine H5N1of Legok strain. Antibody of H5N1 AI in serum was detected by Agar gelprecipitation test (AGPT and an Inhibition Hemmaglutination test (IHT. The highest titre of antibodywas obtained one week after the third immunization. Serum of guinea pigs containing IgG was purifiedusing the Montage Antibody purification kit & spin column with Prosep A media (Millipore. The AI H5N1IgG concentration was 8 mg/ml. AI H5N1 IgG, was then digested with pepsin to obtain F(ab2 fraction andwas called Ab1. The concentration of IgG and F(ab2 and purity of IgG were determined by UVspectrophotometer which showed Ab1 concentration 1 mg/ml. Molecular weight was estimated by sodiumdodecyl sulfate- polyacrilamide gel electrophoresis (SDS-PAGE. Ab2 was produced by immunization ofrabbit with Ab1. The first immunization was carried out by subcutaneous injection with 500 ?g of Ab1emulsified in Complete Freund Adjuvant. The immunization was repeated with the same dose of Ab1emulsified in Incomplete Freund Adjuvan at 1 week intervals. One week after the second immunization,rabbit’s serum was harvested and IgG was purified using the Montage Antibody purification kit & spincolumn with Prosep A media (Millipore. The rabbit IgG, called Ab2, was an anti-idiotypic antibody againstAIV-H5N1. In AGPT, a precipitation line appeared between Ab1 and Ab2. A partial reaction appearedbetween Ab2 and the AI H5N1 antigen was also detected. The results indicated that Ab2 is a possiblecandidate of imunogen for protection against an AI virus H5N1 infection.

  20. Vaccination with recombinant RNA replicon particles protects chickens from H5N1 highly pathogenic avian influenza virus.

    Science.gov (United States)

    Halbherr, Stefan J; Brostoff, Terza; Tippenhauer, Merve; Locher, Samira; Berger Rentsch, Marianne; Zimmer, Gert

    2013-01-01

    Highly pathogenic avian influenza viruses (HPAIV) of subtype H5N1 not only cause a devastating disease in domestic chickens and turkeys but also pose a continuous threat to public health. In some countries, H5N1 viruses continue to circulate and evolve into new clades and subclades. The rapid evolution of these viruses represents a problem for virus diagnosis and control. In this work, recombinant vesicular stomatitis virus (VSV) vectors expressing HA of subtype H5 were generated. To comply with biosafety issues the G gene was deleted from the VSV genome. The resulting vaccine vector VSV*ΔG(HA) was propagated on helper cells providing the VSV G protein in trans. Vaccination of chickens with a single intramuscular dose of 2×10⁸ infectious replicon particles without adjuvant conferred complete protection from lethal H5N1 infection. Subsequent application of the same vaccine strongly boosted the humoral immune response and completely prevented shedding of challenge virus and transmission to sentinel birds. The vaccine allowed serological differentiation of infected from vaccinated animals (DIVA) by employing a commercially available ELISA. Immunized chickens produced antibodies with neutralizing activity against multiple H5 viruses representing clades 1, 2.2, 2.5, and low-pathogenic avian influenza viruses (classical clade). Studies using chimeric H1/H5 hemagglutinins showed that the neutralizing activity was predominantly directed against the globular head domain. In summary, these results suggest that VSV replicon particles are safe and potent DIVA vaccines that may help to control avian influenza viruses in domestic poultry.

  1. Vaccination with recombinant RNA replicon particles protects chickens from H5N1 highly pathogenic avian influenza virus.

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    Stefan J Halbherr

    Full Text Available Highly pathogenic avian influenza viruses (HPAIV of subtype H5N1 not only cause a devastating disease in domestic chickens and turkeys but also pose a continuous threat to public health. In some countries, H5N1 viruses continue to circulate and evolve into new clades and subclades. The rapid evolution of these viruses represents a problem for virus diagnosis and control. In this work, recombinant vesicular stomatitis virus (VSV vectors expressing HA of subtype H5 were generated. To comply with biosafety issues the G gene was deleted from the VSV genome. The resulting vaccine vector VSV*ΔG(HA was propagated on helper cells providing the VSV G protein in trans. Vaccination of chickens with a single intramuscular dose of 2×10⁸ infectious replicon particles without adjuvant conferred complete protection from lethal H5N1 infection. Subsequent application of the same vaccine strongly boosted the humoral immune response and completely prevented shedding of challenge virus and transmission to sentinel birds. The vaccine allowed serological differentiation of infected from vaccinated animals (DIVA by employing a commercially available ELISA. Immunized chickens produced antibodies with neutralizing activity against multiple H5 viruses representing clades 1, 2.2, 2.5, and low-pathogenic avian influenza viruses (classical clade. Studies using chimeric H1/H5 hemagglutinins showed that the neutralizing activity was predominantly directed against the globular head domain. In summary, these results suggest that VSV replicon particles are safe and potent DIVA vaccines that may help to control avian influenza viruses in domestic poultry.

  2. Spatial Modeling of Wild Bird Risk Factors for Highly Pathogenic A(H5N1) Avian Influenza Virus Transmission.

    Science.gov (United States)

    Prosser, Diann J; Hungerford, Laura L; Erwin, R Michael; Ottinger, Mary Ann; Takekawa, John Y; Newman, Scott H; Xiao, Xiangming; Ellis, Erle C

    2016-05-01

    One of the longest-persisting avian influenza viruses in history, highly pathogenic avian influenza virus (HPAIV) A(H5N1), continues to evolve after 18 yr, advancing the threat of a global pandemic. Wild waterfowl (family Anatidae) are reported as secondary transmitters of HPAIV and primary reservoirs for low-pathogenic avian influenza viruses, yet spatial inputs for disease risk modeling for this group have been lacking. Using geographic information software and Monte Carlo simulations, we developed geospatial indices of waterfowl abundance at 1 and 30 km resolutions and for the breeding and wintering seasons for China, the epicenter of H5N1. Two spatial layers were developed: cumulative waterfowl abundance (WAB), a measure of predicted abundance across species, and cumulative abundance weighted by H5N1 prevalence (WPR), whereby abundance for each species was adjusted based on prevalence values and then totaled across species. Spatial patterns of the model output differed between seasons, with higher WAB and WPR in the northern and western regions of China for the breeding season and in the southeast for the wintering season. Uncertainty measures indicated highest error in southeastern China for both WAB and WPR. We also explored the effect of resampling waterfowl layers from 1 to 30 km resolution for multiscale risk modeling. Results indicated low average difference (less than 0.16 and 0.01 standard deviations for WAB and WPR, respectively), with greatest differences in the north for the breeding season and southeast for the wintering season. This work provides the first geospatial models of waterfowl abundance available for China. The indices provide important inputs for modeling disease transmission risk at the interface of poultry and wild birds. These models are easily adaptable, have broad utility to both disease and conservation needs, and will be available to the scientific community for advanced modeling applications.

  3. Biological fitness and natural selection of amantadine resistant variants of avian influenza H5N1 viruses.

    Science.gov (United States)

    Abdelwhab, E M; Veits, Jutta; Mettenleiter, Thomas C

    2017-01-15

    Outbreaks caused by the highly pathogenic H5N1 avian influenza virus (A/H5N1) devastated the poultry industry in several countries and posed a significant pandemic threat. In addition to culling of infected poultry and vaccination, amantadine has been applied in poultry in some countries to control the spread of the virus. The prevalence of the amantadine resistance marker at position 31 (Ser31Asn) of the M2 protein increased over time. However, little is known about the biological fitness and selection of H5N1 amantadine resistant strains over their sensitive counterparts. Here, using reverse genetics we investigated the biological impact of Ser31Asn in M2 commonly seen in viruses in clade 2.2.1.1 in farmed poultry in Egypt. Findings of the current study indicated that the resistance to amantadine conferred by Asn31 evolved rapidly after the application of amantadine in commercial poultry. Both the resistant and sensitive strains replicated at similar levels in avian cell culture. Asn31 increased virus entry into the cells and cell-to-cell spread and was genetically stable for several passages in cell culture. Moreover, upon co-infection of cell culture resistant strains dominated sensitive viruses even in the absence of selection by amantadine. Together, rapid emergence, stability and domination of amantadine-resistant variants over sensitive strains limit the efficacy of amantadine in poultry.

  4. 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.

  5. 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.

  6. Predicting Avian Influenza Co-Infection with H5N1 and H9N2 in Northern Egypt

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    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.

  7. 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).

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

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    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

  9. 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

    between Bangladesh and e. g., Thailand and Vietnam. The primary aim of the current study was to establish ecological determinants associated with the risk of HPAI-H5N1 outbreaks at subdistrict level in Bangladesh. The secondary aim was to explore the performance of two different statistical modeling...

  10. [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.

  11. Genetic evolution analysis of matrix protein 2 gene of avian influenza H5N1 viruses from boundary of Yunnan province

    Institute of Scientific and Technical Information of China (English)

    肖雪

    2013-01-01

    Objective To elucidate the variation in characterizations and genetic evolution of the matrix protein 2 or ion channel protein (M2) genes of avian influenza subtype H5N1 viruses in the boundary region of Yunnan province

  12. 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.

  13. Risk-based surveillance for H5N1 avian influenza virus in wild birds in Great Britain.

    Science.gov (United States)

    Snow, L C; Newson, S E; Musgrove, A J; Cranswick, P A; Crick, H Q P; Wilesmith, J W

    2007-12-01

    Recent outbreaks of the H5N1 strain of avian influenza in Europe have highlighted the need for continuous surveillance and early detection to reduce the likelihood of a major outbreak in the commercial poultry industry. In Great Britain (gb), one possible route by which H5N1 could be introduced into domestic poultry is through migratory wild birds from Europe and Asia. Extensive monitoring data on the 24 wild bird species considered most likely to introduce the virus into GB, and analyses of local poultry populations, were used to develop a risk profile to identify the areas where H5N1 is most likely to enter and spread to commercial poultry. The results indicate that surveillance would be best focused on areas of Norfolk, Suffolk, Lancashire, Lincolnshire, south-west England and the Welsh borders, with areas of lower priority in Anglesey, south-west Wales, north-east Aberdeenshire and the Firth of Forth area of Scotland. These areas have significant poultry populations including a large number of free-range flocks, and a high abundance of the 24 wild bird species.

  14. Vaccination of gallinaceous poultry for H5N1 highly pathogenic avian influenza: current questions and new technology.

    Science.gov (United States)

    Spackman, Erica; Swayne, David E

    2013-12-05

    Vaccination of poultry for avian influenza virus (AIV) is a complex topic as there are numerous technical, logistic and regulatory aspects which must be considered. Historically, control of high pathogenicity (HP) AIV infection in poultry has been accomplished by eradication and stamping out when outbreaks occur locally. Since the H5N1 HPAIV from Asia has spread and become enzootic, vaccination has been used on a long-term basis by some countries to control the virus, other countries have used it temporarily to aid eradication efforts, while others have not used it at all. Currently, H5N1 HPAIV is considered enzootic in China, Egypt, Viet Nam, India, Bangladesh and Indonesia. All but Bangladesh and India have instituted vaccination programs for poultry. Importantly, the specifics of these programs differ to accommodate different situations, resources, and industry structure in each country. The current vaccines most commonly used are inactivated whole virus vaccines, but vectored vaccine use is increasing. Numerous technical improvements to these platforms and novel vaccine platforms for H5N1 vaccines have been reported, but most are not ready to be implemented in the field.

  15. The pathogenicity and host immune response associated with H5N1 highly pathogenic avian influenza virus in quail.

    Science.gov (United States)

    Uno, Yukiko; Usui, Tatsufumi; Soda, Kosuke; Fujimoto, Yoshikazu; Takeuchi, Takashi; Ito, Hiroshi; Ito, Toshihiro; Yamaguchi, Tsuyoshi

    2013-05-02

    Quail, like chickens, are susceptible to H5N1 subtype highly pathogenic avian influenza virus (HPAIV). Both birds experience high mortality, but quail usually survive a few more days than chicken. To understand why, we monitored quail and chickens after inoculation with 10(6) fifty-percent egg infectious doses of HPAIV A/whooper swan/Aomori/1/2008 (H5N1). The clinical course initiated as depression at 48 hr post inoculation (h.p.i.) in quail and at 36 h.p.i. in chicken, and all infected birds died. Mean death time of quail (91 hr) was significantly longer than that of chicken (66 hr). The virus titers of most tissue samples collected before death were not significantly different. At 24 h.p.i., interferon gamma (IFN-γ) mRNA expression in peripheral blood mononuclear cells (PBMC) was up-regulated in the quail but down-regulated in the chicken, although TLR-7 and seven other cytokines showed no significant differences between quail and chicken. The viral load in quail PBMC was significantly lower than that in chickens. These results suggest that the induction of IFN-γ after HPAIV infection in quail is related to lower titer of HPAIV. In conclusion, the different clinical courses observed between quail and chicken infected with H5N1 HPAIV might be caused by different IFN-γ responses against the HPAIV infection.

  16. 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.

  17. A computationally optimized broadly reactive H5 hemagglutinin vaccine provides protection against homologous and heterologous H5N1 highly pathogenic avian influenza virus infection in chickens

    Science.gov (United States)

    Since its emergence in 1996 in China, H5N1 highly pathogenic avian influenza (HPAI) virus has continuously evolved into different genetic clades that have created challenges to maintaining antigenically relevant H5N1 vaccine seeds. Therefore, a universal (multi-hemagglutinin [HA] subtype) or more c...

  18. Prevalence of Antibodies against Avian Influenza A (H5N1) Virus among Cullers and Poultry Workers in Ho Chi Minh City, 2005

    NARCIS (Netherlands)

    Schultsz, C.; Nguyen, V.D.; Hai, L.T.; Do, Q.H.; Peiris, J.S.M.; Lim, W.; Garcia, J.M.; Nguyen, D.T.; Nguyen, T.H.L.; Huynh, H.T.; Phan, X.T.; van Doorn, H.R.; Nguyen, V.V.C.; Farrar, J.; de Jong, M.D.

    2009-01-01

    Background: Between 2003 and 2005, highly pathogenic avian influenza A (H5N1) viruses caused large scale outbreaks in poultry in the Ho Chi Minh City area in Vietnam. We studied the prevalence of antibodies against H5N1 in poultry workers and cullers who were active in the program in Ho Chi Minh Cit

  19. 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.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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

  2. 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.

  3. 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.

  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. Spatio-temporal magnitude and direction of highly pathogenic avian influenza (H5N1 outbreaks in Bangladesh.

    Directory of Open Access Journals (Sweden)

    Syed S U Ahmed

    Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: To determine the magnitude and spatial pattern of the highly pathogenic avian influenza A subtype H5N1 virus outbreaks over space and time in poultry from 2007 to 2009 in Bangladesh, we applied descriptive and analytical spatial statistics. Temporal distribution of the outbreaks revealed three independent waves of outbreaks that were clustered during winter and spring. The descriptive analyses revealed that the magnitude of the second wave was the highest as compared to the first and third waves. Exploratory mapping of the infected flocks revealed that the highest intensity and magnitude of the outbreaks was systematic and persistent in an oblique line that connects south-east to north-west through the central part of the country. The line follows the Brahmaputra-Meghna river system, the junction between Central Asian and East Asian flyways, and the major poultry trading route in Bangladesh. Moreover, several important migratory bird areas were identified along the line. Geostatistical analysis revealed significant latitudinal directions of outbreak progressions that have similarity to the detected line of intensity and magnitude. CONCLUSION/SIGNIFICANCE: The line of magnitude and direction indicate the necessity of mobilizing maximum resources on this line to strengthen the existing surveillance.

  6. Deteksi Virus Avian Influenza H5N1 pada Anak Ayam Umur Satu Hari dengan Teknik Imunohistokimia

    Directory of Open Access Journals (Sweden)

    Sophia Setyawati

    2010-12-01

    Full Text Available Avian Influenza (AI or bird flu caused by virus H5N1 is still present in Indonesia. The Department ofAgriculture of Indonesia has banned poultry distribution from endemic to non endemic area, except fordistribution of day old chick (DOC. The aim of this research was to detect AI virus infection in DOCdistributed from AI endemic to AI non endemic areas. Two hundred and forty DOCs from farms in WestJava and Banten were collected from Soekarno Hatta airport. Their antibody titers were examined againstAI virus by Haemaglutination Inhibition (HI test. The AI virus detected in tissues (trachea, lung, heart,kidney, liver, and intestine by immunohistochemistry technique. Detection of AI virus using anti AI H5N1monoclonal antibody was conducted AEC as chromogen. The result showed that 66,2% of DOC were positiveAI and 33,8% were negative AI. The 66,2% of positive samples, 43,3% showing the presence of AI antigenin trachea, lung and intestine, and 22,9% were presence in liver and kidney. DOCs were infected AI viruswith subclinical symptoms and they were potential as the source of rapid AI spread in Indonesia. It istherefore important to take a very cautious measure to prevent the spread of AI via DOC from AI endemicto free area.

  7. Global alert to avian influenza virus infection: from H5N1 to H7N9.

    Science.gov (United States)

    Poovorawan, Yong; Pyungporn, Sunchai; Prachayangprecha, Slinporn; Makkoch, Jarika

    2013-07-01

    Outbreak of a novel influenza virus is usually triggered by mutational change due to the process known as 'antigenic shift' or re-assortment process that allows animal-to-human or avian-to-human transmission. Birds are a natural reservoir for the influenza virus, and subtypes H5, H7, and H9 have all caused outbreaks of avian influenza in human populations. An especially notorious strain is the HPAI influenza virus H5N1, which has a mortality rate of approximately 60% and which has resulted in numerous hospitalizations, deaths, and significant economic loss. In March 2013, in Eastern China, there was an outbreak of the novel H7N9 influenza virus, which although less pathogenic in avian species, resulted in 131 confirmed cases and 36 deaths in humans over a two-month span. The rapid outbreak of this virus caused global concern but resulted in international cooperation to control the outbreak. Furthermore, cooperation led to valuable research-sharing including genome sequencing of the virus, the development of rapid and specific diagnosis, specimen sharing for future studies, and vaccine development. Although a H7N9 pandemic in the human population is possible due to its rapid transmissibility and extensive surveillance, the closure of the live-bird market will help mitigate the possibility of another H7N9 outbreak. In addition, further research into the source of the outbreak, pathogenicity of the virus, and the development of specific and sensitive detection assays will be essential for controlling and preparing for future H7N9 outbreaks.

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

    Science.gov (United States)

    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.

  9. 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

    Directory of Open Access Journals (Sweden)

    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.

  10. 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

  11. 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

  12. Risk assessment applied to Spain's prevention strategy against highly pathogenic avian influenza virus H5N1.

    Science.gov (United States)

    Martínez, M; Muñoz, M J; De la Torre, A; Martínez, B; Iglesias, I; Sánchez-Vizcaíno, J M

    2007-03-01

    Notifiable avian influenza (NAI) had never been reported in Spain, until July 2006 when a dead Great Crested Grebe (Podiceps cristatus) was found positive to the highly pathogenic H5N1 subtype as part of the active wild bird surveillance plan. The current program of the Spanish Ministry of Agriculture, Fisheries, and Food (MAPA)'s strategic preventive plan against NAI is divided in the following parts: identification of risk areas and risk wild bird species, increased biosecurity measures, early detection of infection with surveillance intensification and development of rapid diagnostic tests, and other policies, which include continuing education and training to ensure early detection of the disease. In 2003 an active surveillance plan was introduced for domestic fowl; the plan was extended to wild birds in 2004. A total of 18,780 samples in poultry and 3687 samples in wild birds had been analyzed through December 2005 to detect the presence and spread of avian influenza subtypes H5 and H7. In the present work we suggest some contributions to be implemented in MAPA's action plan: 1) the identification of risks because of migratory birds, within the risk assessment of the introduction of NAI virus in Spain and 2) an interactive digital simulator of the disease developed for continuing education and training.

  13. High-yield production of a stable Vero cell-based vaccine candidate against the highly pathogenic avian influenza virus H5N1

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Fangye; Zhou, Jian; Ma, Lei; Song, Shaohui; Zhang, Xinwen; Li, Weidong; Jiang, Shude [No. 5, Department of Bioproducts, Institute of Medical Biology, Chinese Academy of Medical Science and Pecking Union Medical College, Jiaoling Avenue 935, Kunming, Yunnan Province 650102, People' s Republic of China (China); Wang, Yue, E-mail: euy-tokyo@umin.ac.jp [National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Yingxin Lane 100, Xicheng District, Beijing 100052, People' s Republic of China (China); Liao, Guoyang, E-mail: liaogy@21cn.com [No. 5, Department of Bioproducts, Institute of Medical Biology, Chinese Academy of Medical Science and Pecking Union Medical College, Jiaoling Avenue 935, Kunming, Yunnan Province 650102, People' s Republic of China (China)

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer Vero cell-based HPAI H5N1 vaccine with stable high yield. Black-Right-Pointing-Pointer Stable high yield derived from the YNVa H3N2 backbone. Black-Right-Pointing-Pointer H5N1/YNVa has a similar safety and immunogenicity to H5N1delta. -- Abstract: Highly pathogenic avian influenza (HPAI) viruses pose a global pandemic threat, for which rapid large-scale vaccine production technology is critical for prevention and control. Because chickens are highly susceptible to HPAI viruses, the supply of chicken embryos for vaccine production might be depleted during a virus outbreak. Therefore, developing HPAI virus vaccines using other technologies is critical. Meeting vaccine demand using the Vero cell-based fermentation process has been hindered by low stability and yield. In this study, a Vero cell-based HPAI H5N1 vaccine candidate (H5N1/YNVa) with stable high yield was achieved by reassortment of the Vero-adapted (Va) high growth A/Yunnan/1/2005(H3N2) (YNVa) virus with the A/Anhui/1/2005(H5N1) attenuated influenza vaccine strain (H5N1delta) using the 6/2 method. The reassorted H5N1/YNVa vaccine maintained a high hemagglutination (HA) titer of 1024. Furthermore, H5N1/YNVa displayed low pathogenicity and uniform immunogenicity compared to that of the parent virus.

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

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    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.

  15. Preparation and immune activity analysis of H5N1 subtype avian influenza virus recombinant protein-based vaccine.

    Science.gov (United States)

    Xie, Q M; Ji, J; Du, L Q; Cao, Y C; Wei, L; Xue, C Y; Qin, J P; Ma, J Y; Bi, Y Z

    2009-08-01

    Avian influenza is a severe disease among farmed poultry and free-living birds and a constant threat to the commercial chicken industry around the world. Hemagglutinin (HA) is the major immunogen on the envelope of influenza A virus and is the predominant inducer of neutralizing antibody. To obtain the bioactive antigen proteins in large quantities, a new protein expression vector pBCX was constructed, which is based on the pET32a vector. The HA gene of the H5N1 subtype of avian influenza virus (AIV) was inserted into the pBCX vector and expressed efficiently in Escherichia coli BL21 (DE3). Fused expression of the exogenous gene and msyB produced a 97-kDa msyB-HA fusion protein. Sodium dodecyl sulfate-PAGE combined with scanning analysis demonstrated that the msyB-HA fusion protein accounted for 29.5% of the total bacterial protein, 90.5% being soluble. The msyB-HA fusion protein was purified with nondenaturing 50% Ni-NTA column chromatography, and the result showed that 24 mg of purified msyB-HA fusion protein could be obtained from 1 L of induced expression bacterial culture medium. The comparative results in the present study showed that pBCX was superior to pET32a as a protein expression vector. Western blotting showed the recombinant msyB-HA (rHA) to have better antigenic activity, which may be the result from the better posttranslation protein modification and folding in the pBCX expression system. With the rHA fusion protein as antigen, we successfully prepared and screened specific monoclonal antibodys against the H5N1 subtype AIV, which indicated that the rHA had antigen epitopes and biofunctions. The immune test confirmed that the rHA protein vaccine could also induce high neutralizing antibodies, and the AIV challenge test proved that the rHA protein-based vaccine could prevent the corresponding infection. This study demonstrates that the recombinant HA protein produced by the pBCX expression system could be used as a recombinant protein-based vaccine

  16. 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...

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. Evidence for the Convergence Model: The Emergence of Highly Pathogenic Avian Influenza (H5N1) in Viet Nam.

    Science.gov (United States)

    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.

  2. Evidence for the Convergence Model: The Emergence of Highly Pathogenic Avian Influenza (H5N1 in Viet Nam.

    Directory of Open Access Journals (Sweden)

    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.

  3. 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.

  4. Experimentally infected domestic ducks show efficient transmission of Indonesian H5N1 highly pathogenic avian influenza virus, but lack persistent viral shedding.

    Science.gov (United States)

    Wibawa, Hendra; Bingham, John; Nuradji, Harimurti; Lowther, Sue; Payne, Jean; Harper, Jenni; Junaidi, Akhmad; Middleton, Deborah; Meers, Joanne

    2014-01-01

    Ducks are important maintenance hosts for avian influenza, including H5N1 highly pathogenic avian influenza viruses. A previous study indicated that persistence of H5N1 viruses in ducks after the development of humoral immunity may drive viral evolution following immune selection. As H5N1 HPAI is endemic in Indonesia, this mechanism may be important in understanding H5N1 evolution in that region. To determine the capability of domestic ducks to maintain prolonged shedding of Indonesian clade 2.1 H5N1 virus, two groups of Pekin ducks were inoculated through the eyes, nostrils and oropharynx and viral shedding and transmission investigated. Inoculated ducks (n = 15), which were mostly asymptomatic, shed infectious virus from the oral route from 1 to 8 days post inoculation, and from the cloacal route from 2-8 dpi. Viral ribonucleic acid was detected from 1-15 days post inoculation from the oral route and 1-24 days post inoculation from the cloacal route (cycle threshold Indonesian clade 2.1 H5N1 highly pathogenic avian influenza virus does not persist in individual ducks after acute infection.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Host-specific exposure and fatal neurologic disease in wild raptors from highly pathogenic avian influenza virus H5N1 during the 2006 outbreak in Germany.

    Science.gov (United States)

    van den Brand, Judith Ma; Krone, Oliver; Wolf, Peter U; van de Bildt, Marco W G; van Amerongen, Geert; Osterhaus, Albert D M E; Kuiken, Thijs

    2015-03-05

    Raptors may contract highly pathogenic avian influenza virus H5N1 by hunting or scavenging infected prey. However, natural H5N1 infection in raptors is rarely reported. Therefore, we tested raptors found dead during an H5N1 outbreak in wild waterbirds in Mecklenburg-Western Pomerania, Germany, in 2006 for H5N1-associated disease. We tested 624 raptors of nine species-common buzzard (385), Eurasian sparrowhawk (111), common kestrel (38), undetermined species of buzzard (36), white-tailed sea eagle (19), undetermined species of raptor (12), northern goshawk (10), peregrine falcon (6), red kite (3), rough-legged buzzard (3), and western marsh-harrier (1)-for H5N1 infection in tracheal or combined tracheal/cloacal swabs of all birds, and on major tissues of all white-tailed sea eagles. H5N1 infection was detected in two species: common buzzard (12 positive, 3.1%) and peregrine falcon (2 positive, 33.3%). In all necropsied birds (both peregrine falcons and the six freshest common buzzards), H5N1 was found most consistently and at the highest concentration in the brain, and the main H5N1-associated lesion was marked non-suppurative encephalitis. Other H5N1-associated lesions occurred in air sac, lung, oviduct, heart, pancreas, coelomic ganglion, and adrenal gland. Our results show that the main cause of death in H5N1-positive raptors was encephalitis. Our results imply that H5N1 outbreaks in wild waterbirds are more likely to lead to exposure to and mortality from H5N1 in raptors that hunt or scavenge medium-sized birds, such as common buzzards and peregrine falcons, than in raptors that hunt small birds and do not scavenge, such as Eurasian sparrowhawks and common kestrels.

  8. 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.

  9. Three-dimensional printed magnetophoretic system for the continuous flow separation of avian influenza H5N1 viruses.

    Science.gov (United States)

    Wang, Yuhe; Li, Yanbin; Wang, Ronghui; Wang, Maohua; Lin, Jianhan

    2017-01-31

    As a result of the low concentration of avian influenza viruses in samples for routine screening, the separation and concentration of these viruses are vital for their sensitive detection. We present a novel three-dimensional printed magnetophoretic system for the continuous flow separation of the viruses using aptamer-modified magnetic nanoparticles, a magnetophoretic chip, a magnetic field, and a fluidic controller. The magnetic field was designed based on finite element magnetic simulation and developed using neodymium magnets with a maximum intensity of 0.65 T and a gradient of 32 T/m for dragging the nanoparticle-virus complexes. The magnetophoretic chip was designed by SOLIDWORKS and fabricated by a three-dimensional printer with a magnetophoretic channel for the continuous flow separation of the viruses using phosphate-buffered saline as carrier flow. The fluidic controller was developed using a microcontroller and peristaltic pumps to inject the carrier flow and the viruses. The trajectory of the virus-nanoparticle complexes was simulated using COMSOL for optimization of the carrier flow and the magnetic field, respectively. The results showed that the H5N1 viruses could be captured, separated, and concentrated using the proposed magnetophoretic system with the separation efficiency up to 88% in a continuous flow separation time of 2 min for a sample volume of 200 μL.

  10. Transmission of the highly pathogenic avian influenza virus H5N1 within flocks during the 2004 epidemic in Thailand.

    Science.gov (United States)

    Tiensin, Thanawat; Nielen, Mirjam; Vernooij, Hans; Songserm, Thaweesak; Kalpravidh, Wantanee; Chotiprasatintara, Sirikan; Chaisingh, Arunee; Wongkasemjit, Surapong; Chanachai, Karoon; Thanapongtham, Weerapong; Srisuvan, Thinnarat; Stegeman, Arjan

    2007-12-01

    This present study is the first to quantify the transmission of avian influenza virus H5N1 within flocks during the 2004 epidemic in Thailand. It uses the flock-level mortality data to estimate the transmission-rate parameter ( beta ) and the basic reproduction number (R(0)). The point estimates of beta varied from 2.26/day (95% confidence interval [CI], 2.01-2.55) for a 1-day infectious period to 0.66/day (95% CI, 0.50-0.87) for a 4-day infectious period, whereas the accompanying R(0) varied from 2.26 (95% CI, 2.01-2.55) to 2.64 (95% CI, 2.02-3.47). Although the point estimates of beta of backyard chickens and fighting cocks raised together were lower than those of laying hens and broiler chickens, this difference was not statistically significant. These results will enable us to assess the control measures in simulation studies. They also indicate that, for the elimination of the virus, a critical proportion of the susceptible poultry population in a flock (i.e., 80% of the population) needs to be vaccinated.

  11. 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.

  12. Spatiotemporal distributions of reported cases of the avian influenza H5N1 (bird flu) in Southern China in early 2004.

    Science.gov (United States)

    Oyana, Tonny J; Dai, Dajun; Scott, Kara E

    2006-12-01

    This study investigates spatiotemporal distributions of reported cases of the avian influenza H5N1 (bird flu) in Southern China in early 2004. Forty-nine cases of the avian influenza H5N1 covering a 6-week period (January 19, 2004, through March 9, 2004) were compiled from the Chinese Ministry of Agriculture and the World Health Organization. Geographic information systems (GIS) techniques combined with statistical techniques were used to analyze the spatiotemporal variation of reported cases of avian influenza. Using Oden's direction method, we also explored the spatiotemporal interaction of individual-level avian influenza cases during the study duration. The peak period (temporal clustering) for the epidemiological avian influenza outbreak occurred between the third and fourth weeks. Although we observed a major northeast-southwest distribution of the avian influenza H5N1 cases, there was no significant spatiotemporal association in average "direction of advance" of these cases. The directional finding is very consistent with the major migratory bird routes in East Asia, but owing to weak surveillance and reporting systems in the region, the study findings warrant further evaluation.

  13. 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.

  14. 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.

  15. 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.

  16. Surveillance for Asian H5N1 avian influenza in the United States. The government initiates early detection efforts in wild birds

    Science.gov (United States)

    Ip, Hon S.; Slota, Paul G.

    2006-01-01

    Increasing concern over the potential for migratory birds to introduce the Asian H5N1 strain of avian influenza to North America prompted the White House Policy Coordinating Committee for Pandemic Influenza Preparedness to request that the U.S. Departments of Agriculture (USDA) and Interior (DOI) develop a plan for the early detection of highly pathogenic avian influenza (HPAI) in the United States. To promote coordination among wildlife, agriculture, and human health agencies on HPAI surveillance efforts, the two Departments worked with representatives from the U.S. Department of Health and Human Services, the International Association of Fish and Wildlife Agencies, and the Alaska Department of Fish and Game to develop the U.S. Interagency Strategic Plan for Early Detection of Asian H5N1 Highly Pathogenic Avian Influenza in Wild Migratory Birds.

  17. 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

  18. Eco-Virological Approach for Assessing the Role of Wild Birds in the Spread of Avian Influenza H5N1 along the Central Asian Flyway

    Science.gov (United States)

    2012-02-07

    P. Bright, S. Schwarzbach, and J. Howell from U.S. Geological Survey and J. Lubroth and J. Domenech from FAO for their support. For logistics and...avian influenza H5N1 virus defined by agro - ecological niche. Ecohealth 7: 213–225. 5. Gilbert M, Xiao X, Chaitaweesub P, Kalpravidh W, Premashthira

  19. Comparing introduction to Europe of highly pathogenic avian influenza viruses A(H5N8) in 2014 and A(H5N1) in 2005

    NARCIS (Netherlands)

    Adlhoch, C.; Gossner, C.; Koch, G.; Brown, I.; Bouwstra, R.J.; Verdonck, F.; Penttinen, P.; Harder, T.

    2014-01-01

    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 descri

  20. Highly pathogenic avian influenza virus H5N1 infection in a long-distance migrant shorebird under migratory and non-migratory states

    NARCIS (Netherlands)

    Reperant, Leslie A.; Bildt, Marco W.G. van de; Amerongen, Geert van; Buehler, Deborah; Osterhaus, Albert D.M.E.; Jenni-Eiermann, Susi; Piersma, Theunis; Kuiken, Thijs

    2011-01-01

    Corticosterone regulates physiological changes preparing wild birds for migration. It also modulates the immune system and may lead to increased susceptibility to infection, with implications for the spread of pathogens, including highly pathogenic avian influenza virus (HPAIV) H5N1. The red knot (C

  1. Highly pathogenic avian influenza virus H5N1 infection in a long-distance migrant shorebird under migratory and non-migratory states

    NARCIS (Netherlands)

    L.A. Reperant (Leslie); M.W.G. van de Bildt (Marco); G. van Amerongen (Geert); D.M. Buehler (Debbie); A.D.M.E. Osterhaus (Albert); S. Jenni-Eiermann (Susi); T. Piersma (Theunis); T. Kuiken (Thijs)

    2011-01-01

    textabstractCorticosterone regulates physiological changes preparing wild birds for migration. It also modulates the immune system and may lead to increased susceptibility to infection, with implications for the spread of pathogens, including highly pathogenic avian influenza virus (HPAIV) H5N1. The

  2. Highly Pathogenic Avian Influenza Virus H5N1 Infection in a Long-Distance Migrant Shorebird under Migratory and Non-Migratory States

    NARCIS (Netherlands)

    Reperant, L.A.; van de Bildt, M.W.G.; van Amerongen, G.; Buehler, D.M.; Osterhaus, A.D.M.E.; Jenni-Eiermann, S.; Piersma, T.; Kuiken, T.

    2011-01-01

    Corticosterone regulates physiological changes preparing wild birds for migration. It also modulates the immune system and may lead to increased susceptibility to infection, with implications for the spread of pathogens, including highly pathogenic avian influenza virus (HPAIV) H5N1. The red knot (C

  3. 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.

  4. 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.

  5. 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.

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

    Science.gov (United States)

    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.

  7. 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.

  8. Real-time RT-PCR assay to differentiate clades of H5N1 avian influenza viruses circulating in Vietnam.

    Science.gov (United States)

    Kis, Z; Jones, J; Creanga, A; Ferdinand, K; Inui, K; Gerloff, N; Davis, C T; Nguyen, T; Donis, R O

    2013-11-01

    Continued circulation and geographical expansion of highly pathogenic avian influenza H5N1 virus have led to the emergence of numerous clades in Vietnam. Although viral RNA sequencing and phylogenetic analysis are the gold standard for H5N1 HA clade designation, limited sequencing capacity in many laboratories precludes rapid H5N1 clade identification and detection of novel viruses. Therefore, a Taqman real-time RT-PCR assay for rapid differentiation of the four major H5N1 clades detected in Vietnam was developed. Using HA sequence alignments of clades 1.1, 2.3.2.1, 2.3.4, and 7 viruses, primers and FAM-labeled probes were designed to target conserved regions characteristic of each clade. The assay was optimized and evaluated using circulating clades of H5N1 collected in Vietnam from 2007 to 2012 and shown to be both sensitive and specific for the differentiation of the four H5N1 clades. The assay provides a useful tool for screening of large specimen collections for HA gene sequencing and phylogenetic analysis and for the rapid identification of molecular clade signatures to support outbreak investigations and surveillance activities. Finally, this assay may be useful to monitor for the emergence of novel or variant clades of H5N1 in Vietnam in the future or in other countries where these particular clades may circulate.

  9. Penerapan Metode Diagnosis Cepat Virus Avian Influenza H5N1 dengan Metode Single Step Multiplex RT-PCR

    Directory of Open Access Journals (Sweden)

    Aris Haryanto

    2010-12-01

    Full Text Available Avian influenza (AI virus is a segmented single stranded (ss RNA virus with negative polarity andbelong to the Orthomyxoviridae family. Diagnose of AI virus can be performed using conventional methodsbut it has low sensitivity and specificity. The objective of the research was to apply rapid, precise, andaccurate diagnostic method for AI virus and also to determine its type and subtype based on the SingleStep Multiplex Reverse Transcriptase-Polymerase Chain Reaction targeting M, H5, and N1 genes. In thismethod M, H5 and NI genes were simultaneously amplified in one PCR tube. The steps of this researchconsist of collecting viral RNAs from 10 different AI samples originated from Maros Disease InvestigationCenter during 2007. DNA Amplification was conducted by Simplex RT-PCR using M primer set. Then, bysingle step multiplex RT-PCR were conducted simultaneously using M, H5 and N1 primers set. The RTPCRproducts were then separated on 1.5% agarose gel, stained by ethidum bromide and visualized underUV transilluminator. Results showed that 8 of 10 RNA virus samples could be amplified by Simplex RTPCRfor M gene which generating a DNA fragment of 276 bp. Amplification using multiplex RT-PCRmethod showed two of 10 samples were AI positive using multiplex RT-PCR, three DNA fragments weregenerated consisting of 276 bp for M gene, 189 bp for H5 gene, and 131 bp for N1. In this study, rapid andeffective diagnosis method for AI virus can be conducted by using simultaneous Single Step Multiplex RTPCR.By this technique type and subtype of AI virus, can also be determined, especially H5N1.

  10. Experimental challenge and pathology of highly pathogenic avian influenza virus H5N1 in dunlin (Calidris alpina), an intercontinental migrant shorebird species

    Science.gov (United States)

    Hall, Jeffrey S.; Franson, J. Christian; Gill, Robert E.; Meteyer, Carol U.; TeSlaa, Joshua L.; Nashold, Sean; Dusek, Robert J.; Ip, Hon S.

    2011-01-01

    Background Shorebirds (Charadriiformes) are considered one of the primary reservoirs of avian influenza. Because these species are highly migratory, there is concern that infected shorebirds may be a mechanism by which highly pathogenic avian influenza virus (HPAIV) H5N1 could be introduced into North America from Asia. Large numbers of dunlin (Calidris alpina) migrate from wintering areas in central and eastern Asia, where HPAIV H5N1 is endemic, across the Bering Sea to breeding areas in Alaska. Low pathogenic avian influenza virus has been previously detected in dunlin, and thus, dunlin represent a potential risk to transport HPAIV to North America. To date no experimental challenge studies have been performed in shorebirds.

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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

    2016-01-01

    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. 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.

  18. 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.

  19. Highly pathogenic Avian Influenza A(H5N1) virus infection among workers at live bird markets, Bangladesh, 2009-2010.

    Science.gov (United States)

    Nasreen, Sharifa; Khan, Salah Uddin; Luby, Stephen P; Gurley, Emily S; Abedin, Jaynal; Zaman, Rashid Uz; Sohel, Badrul Munir; Rahman, Mustafizur; Hancock, Kathy; Levine, Min Z; Veguilla, Vic; Wang, David; Holiday, Crystal; Gillis, Eric; Sturm-Ramirez, Katharine; Bresee, Joseph S; Rahman, Mahmudur; Uyeki, Timothy M; Katz, Jacqueline M; Azziz-Baumgartner, Eduardo

    2015-04-01

    The risk for influenza A(H5N1) virus infection is unclear among poultry workers in countries where the virus is endemic. To assess H5N1 seroprevalence and seroconversion among workers at live bird markets (LBMs) in Bangladesh, we followed a cohort of workers from 12 LBMs with existing avian influenza surveillance. Serum samples from workers were tested for H5N1 antibodies at the end of the study or when LBM samples first had H5N1 virus-positive test results. Of 404 workers, 9 (2%) were seropositive at baseline. Of 284 workers who completed the study and were seronegative at baseline, 6 (2%) seroconverted (7 cases/100 poultry worker-years). Workers who frequently fed poultry, cleaned feces from pens, cleaned food/water containers, and did not wash hands after touching sick poultry had a 7.6 times higher risk for infection compared with workers who infrequently performed these behaviors. Despite frequent exposure to H5N1 virus, LBM workers showed evidence of only sporadic infection.

  20. Proteome Response of Chicken Embryo Fibroblast Cells to Recombinant H5N1 Avian Influenza Viruses with Different Neuraminidase Stalk Lengths

    Science.gov (United States)

    Li, Yongtao; Ming, Fan; Huang, Huimin; Guo, Kelei; Chen, Huanchun; Jin, Meilin; Zhou, Hongbo

    2017-01-01

    The variation on neuraminidase (NA) stalk region of highly pathogenic avian influenza H5N1 virus results in virulence change in animals. In our previous studies, the special NA stalk-motif of H5N1 viruses has been demonstrated to play a significant role in the high virulence and pathogenicity in chickens. However, the molecular mechanisms underlying the pathogenicity of viruses with different NA stalk remain poorly understood. This study presents a comprehensive characterization of the proteome response of chicken cells to recombinant H5N1 virus with stalk-short NA (rNA-wt) and the stalkless NA mutant virus (rSD20). 208 proteins with differential abundance profiles were identified differentially expressed (DE), and these proteins were mainly related to stress response, transcription regulation, transport, metabolic process, cellular component and cytoskeleton. Through Ingenuity Pathways Analysis (IPA), the significant biological functions of DE proteins represented included Post-Translational Modification, Protein Folding, DNA Replication, Recombination and Repair. It was interesting to find that most DE proteins were involved in the TGF-β mediated functional network. Moreover, the specific DE proteins may play important roles in the innate immune responses and H5N1 virus replication. Our data provide important information regarding the comparable host response to H5N1 influenza virus infection with different NA stalk lengths. PMID:28079188

  1. 5'PPP-RNA induced RIG-I activation inhibits drug-resistant avian H5N1 as well as 1918 and 2009 pandemic influenza virus replication

    Directory of Open Access Journals (Sweden)

    García-Sastre Adolfo

    2010-05-01

    Full Text Available Abstract Background Emergence of drug-resistant strains of influenza viruses, including avian H5N1 with pandemic potential, 1918 and 2009 A/H1N1 pandemic viruses to currently used antiviral agents, neuraminidase inhibitors and M2 Ion channel blockers, underscores the importance of developing novel antiviral strategies. Activation of innate immune pathogen sensor Retinoic Acid Inducible Gene-I (RIG-I has recently been shown to induce antiviral state. Results In the present investigation, using real time RT-PCR, immunofluorescence, immunoblot, and plaque assay we show that 5'PPP-containing single stranded RNA (5'PPP-RNA, a ligand for the intracytoplasmic RNA sensor, RIG-I can be used as a prophylactic agent against known drug-resistant avian H5N1 and pandemic influenza viruses. 5'PPP-RNA treatment of human lung epithelial cells inhibited replication of drug-resistant avian H5N1 as well as 1918 and 2009 pandemic influenza viruses in a RIG-I and type 1 interferon dependant manner. Additionally, 5'PPP-RNA treatment also inhibited 2009 H1N1 viral replication in vivo in mice. Conclusions Our findings suggest that 5'PPP-RNA mediated activation of RIG-I can suppress replication of influenza viruses irrespective of their genetic make-up, pathogenicity, and drug-sensitivity status.

  2. Surveillance plan for the early detection of H5N1 highly pathogenic avian influenza virus in migratory birds in the United States: surveillance year 2009

    Science.gov (United States)

    Brand, Christopher J.

    2009-01-01

    Executive Summary: This Surveillance Plan (Plan) describes plans for conducting surveillance of wild birds in the United States and its Territories and Freely-Associated States to provide for early detection of the introduction of the H5N1 Highly Pathogenic Avian Influenza (HPAI) subtype of the influenza A virus by migratory birds during the 2009 surveillance year, spanning the period of April 1, 2009 - March 31, 2010. The Plan represents a continuation of surveillance efforts begun in 2006 under the Interagency Strategic Plan for the Early Detection of H5N1 Highly Pathogenic Avian Influenza in Wild Migratory Birds (U.S. Department of Agriculture and U.S. Department of the Interior, 2006). The Plan sets forth sampling plans by: region, target species or species groups to be sampled, locations of sampling, sample sizes, and sampling approaches and methods. This Plan will be reviewed annually and modified as appropriate for subsequent surveillance years based on evaluation of information from previous years of surveillance, changing patterns and threats of H5N1 HPAI, and changes in funding availability for avian influenza surveillance. Specific sampling strategies will be developed accordingly within each of six regions, defined here as Alaska, Hawaiian/Pacific Islands, Lower Pacific Flyway (Washington, Oregon, California, Idaho, Nevada, Arizona), Central Flyway, Mississippi Flyway, and Atlantic Flyway.

  3. Secondary structural analysis of the mRNA regions encoding the hemagglutinin cleavage site basic amino acids of the avian influenza virus H5N1 subtype samples

    Institute of Scientific and Technical Information of China (English)

    ZHANG SuXia; WANG Xin; CHEN XueFeng; CAO Huai; ZHANG Wen; LIU CiQuan

    2008-01-01

    Here we report the codon bias and the mRNA secondary structural features of the hemagglutinin (HA) cleavage site basic amino acid regions of avian influenza virus H5N1 subtypes. We have developed a dynamic extended folding strategy to predict RNA secondary structure with RNAstructure 4.1 program in an iterative extension process. Statistical analysis of the sequences showed that the HA cleavage site basic amino acids favor the adenine-rich codons, and the corresponding mRNA fragments are mainly in the folding states of single-stranded loops. Our sequential and structural analyses showed that to prevent and control these highly pathogenic viruses, that is, to inhibit the gene expression of avian influenza virus H5N1 subtypes, we should consider the single-stranded loop regions of the HA cleavage site-coding sequences as the targets of RNA interference.

  4. 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 (H5N1) viruses. These reports represent the first reported infections with these viruses in U.S. wild or domestic birds. Although these viruses are not known to have caused disease in humans, their appearance in North America might increase the likelihood of human infection in the United States. Human infection with other avian influenza viruses, such as HPAI (H5N1) and (H5N6) viruses and (H7N9) virus, has been associated with severe, sometimes fatal, disease, usually following contact with poultry.

  5. 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.

  6. 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

  7. Unusually High Mortality in Waterfowl Caused by Highly Pathogenic Avian Influenza A(H5N1) in Bangladesh

    DEFF Research Database (Denmark)

    Haider, Najmul; Sturm-Ramirez, K.; Khan, S. U.;

    2017-01-01

    a survey in three of these villages to identify suspected human influenza-like illness cases and collected nasopharyngeal and throat swabs. We tested all swabs by real-time RT-PCR, sequenced cultured viruses, and examined tissue samples by histopathology and immunohistochemistry to detect and characterize...... and immunohistochemistry staining of avian influenza viral antigens were recognized in the brain, pancreas and intestines of ducks and chickens. We identified ten human cases showing signs compatible with influenza-like illness; four were positive for influenza A/H3; however, none were positive for influenza A/H5...

  8. Experimental infection of a North American raptor, American Kestrel (Falco sparverius), with highly pathogenic avian influenza virus (H5N1).

    Science.gov (United States)

    Hall, Jeffrey S; Ip, Hon S; Franson, J Christian; Meteyer, Carol; Nashold, Sean; TeSlaa, Joshua L; French, John; Redig, Patrick; Brand, Christopher

    2009-10-22

    Several species of wild raptors have been found in Eurasia infected with highly pathogenic avian influenza virus (HPAIV) subtype H5N1. Should HPAIV (H5N1) reach North America in migratory birds, species of raptors are at risk not only from environmental exposure, but also from consuming infected birds and carcasses. In this study we used American kestrels as a representative species of a North American raptor to examine the effects of HPAIV (H5N1) infection in terms of dose response, viral shedding, pathology, and survival. Our data showed that kestrels are highly susceptible to HPAIV (H5N1). All birds typically died or were euthanized due to severe neurologic disease within 4-5 days of inoculation and shed significant amounts of virus both orally and cloacally, regardless of dose administered. The most consistent microscopic lesions were necrosis in the brain and pancreas. This is the first experimental study of HPAIV infection in a North American raptor and highlights the potential risks to birds of prey if HPAIV (H5N1) is introduced into North America.

  9. Differences in the Epidemiology of Childhood Infections with Avian Influenza A H7N9 and H5N1 Viruses

    Science.gov (United States)

    Chen, Xiaowen; Zhao, Na; Luo, Mengyun; Dong, Yuanyuan

    2016-01-01

    The difference between childhood infections with avian influenza viruses A(H5N1) and A(H7N9) remains an unresolved but critically important question. We compared the epidemiological characteristics of 244 H5N1 and 41 H7N9 childhood cases (H7N9 childhood infections (31.1% vs. 6.4%, p = 0.000). However, the two groups did not differ significantly in age (median age: 5.0 vs. 5.5 y, p = 0.0651). The proportion of clustered cases was significantly greater among children infected with H5N1 than among children infected with H7N9 [46.7% (71/152) vs. 23.6% (13/55), p = 0.005], and most of the childhood cases were identified as secondary cases [46.4% (45/97) vs. 33.3% (10/30), p = 0.000]. Mild status accounted for 79.49% and 22.66%, severe status for 17.95% and 2.34%, and fatal cases for 2.56% and 75.00% of the H7N9 and H5N1 childhood infection cases (all pH7N9 childhood cluster cases were identified. In conclusion, lower severity and greater transmission were found in the H7N9 childhood cases than in the H5N1 childhood cases. PMID:27695069

  10. Experimental infection of a North American raptor, American Kestrel (Falco sparverius, with highly pathogenic avian influenza virus (H5N1.

    Directory of Open Access Journals (Sweden)

    Jeffrey S Hall

    Full Text Available Several species of wild raptors have been found in Eurasia infected with highly pathogenic avian influenza virus (HPAIV subtype H5N1. Should HPAIV (H5N1 reach North America in migratory birds, species of raptors are at risk not only from environmental exposure, but also from consuming infected birds and carcasses. In this study we used American kestrels as a representative species of a North American raptor to examine the effects of HPAIV (H5N1 infection in terms of dose response, viral shedding, pathology, and survival. Our data showed that kestrels are highly susceptible to HPAIV (H5N1. All birds typically died or were euthanized due to severe neurologic disease within 4-5 days of inoculation and shed significant amounts of virus both orally and cloacally, regardless of dose administered. The most consistent microscopic lesions were necrosis in the brain and pancreas. This is the first experimental study of HPAIV infection in a North American raptor and highlights the potential risks to birds of prey if HPAIV (H5N1 is introduced into North America.

  11. Experimental infection of a North American raptor, American kestrel (Falco sparverius), with highly pathogenic avian influenza virus (H5N1)

    Science.gov (United States)

    Hall, J.S.; Ip, H.S.; Franson, J.C.; Meteyer, C.; Nashold, S.; Teslaa, J.L.; French, J.; Redig, P.; Brand, C.

    2009-01-01

    Several species of wild raptors have been found in Eurasia infected with highly pathogenic avian influenza virus (HPAIV) subtype H5N1. Should HPAIV (H5N1) reach North America in migratory birds, species of raptors are at risk not only from environmental exposure, but also from consuming infected birds and carcasses. In this study we used American kestrels as a representative species of a North American raptor to examine the effects of HPAIV (H5N1) infection in terms of dose response, viral shedding, pathology, and survival. Our data showed that kestrels are highly susceptible to HPAIV (H5N1). All birds typically died or were euthanized due to severe neurologic disease within 4-5 days of inoculation and shed significant amounts of virus both orally and cloacally, regardless of dose administered. The most consistent microscopic lesions were necrosis in the brain and pancreas. This is the first experimental study of HPAIV infection in a North American raptor and highlights the potential risks to birds of prey if HPAIV (H5N1) is introduced into North America.

  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. Evaluation of a conserved HA274-288 epitope to detect antibodies to highly pathogenic avian influenza virus H5N1 in Indonesian commercial poultry.

    Science.gov (United States)

    Wawegama, Nadeeka K; Tarigan, Simson; Indriani, Risa; Selleck, Paul; Adjid, Rm Abdul; Syafriati, Tati; Hardiman; Durr, Peter A; Ignjatovic, Jagoda

    2016-08-01

    A peptide enzyme linked immunosorbent assay (ELISA) based on an epitope in the haemagglutinin (HA) of avian influenza virus H5N1, amino acid positions 274-288 (HA274-288) was evaluated for detection of H5N1-specific antibodies. An optimized ELISA based on the tetrameric form of the HA274-288 epitope designated MP15 gave low background with non-immune chicken sera and detected vaccinated and infected birds. The HA274-288 epitope was highly conserved in Indonesian H5N1 strains and antibody responses were detected in the majority of the vaccinated chickens regardless of the H5N1 strain used for vaccination. The HA274-288 epitope was also conserved in the majority of H5N1 strains from the neighbouring Asian region, and other H5 subtypes potentially allowing for a wider use of the MP15 ELISA in H5N1 vaccinated and infected flocks. The MP15 ELISA results correlated significantly with haemagglutination inhibition (HI) test results and test sensitivity and specificity were 87% and 92%, respectively. The MP15 ELISA titres were significantly higher than the HI titres in all immune sera allowing for sera to be tested at a single dilution of 1:400 which is of advantage in routine surveillance. The study indicated that the MP15 ELISA is potentially useful for serological detection of H5N1 vaccinated or infected poultry and to have some advantages over the standard HI test for routine monitoring of flocks' immunity after vaccination.

  15. The Use of Spatial and Spatiotemporal Modeling for Surveillance of H5N1 Highly Pathogenic Avian Influenza in Poultry in the Middle East.

    Science.gov (United States)

    Alkhamis, Mohammad; Hijmans, Robert J; Al-Enezi, Abdullah; Martínez-López, Beatriz; Perea, Andres M

    2016-05-01

    Since 2005, H5N1 highly pathogenic avian influenza virus (HPAIV) has severely impacted the economy and public health in the Middle East (ME) with Egypt as the most affected country. Understanding the high-risk areas and spatiotemporal distribution of the H5N1 HPAIV in poultry is prerequisite for establishing risk-based surveillance activities at a regional level in the ME. Here, we aimed to predict the geographic range of H5N1 HPAIV outbreaks in poultry in the ME using a set of environmental variables and to investigate the spatiotemporal clustering of outbreaks in the region. Data from the ME for the period 2005-14 were analyzed using maximum entropy ecological niche modeling and the permutation model of the scan statistics. The predicted range of high-risk areas (P > 0.60) for H5N1 HPAIV in poultry included parts of the ME northeastern countries, whereas the Egyptian Nile delta and valley were estimated to be the most suitable locations for occurrence of H5N1 HPAIV outbreaks. The most important environmental predictor that contributed to risk for H5N1 HPAIV was the precipitation of the warmest quarter (47.2%), followed by the type of global livestock production system (18.1%). Most significant spatiotemporal clusters (P < 0.001) were detected in Egypt, Turkey, Kuwait, Saudi Arabia, and Sudan. Results suggest that more information related to poultry holding demographics is needed to further improve prediction of risk for H5N1 HPAIV in the ME, whereas the methodology presented here may be useful in guiding the design of surveillance programs and in identifying areas in which underreporting may have occurred.

  16. Insight into live bird markets of Bangladesh: an overview of the dynamics of transmission of H5N1 and H9N2 avian influenza viruses.

    Science.gov (United States)

    Turner, Jasmine C M; Feeroz, Mohammed M; Hasan, M Kamrul; Akhtar, Sharmin; Walker, David; Seiler, Patrick; Barman, Subrata; Franks, John; Jones-Engel, Lisa; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Kayali, Ghazi; Webster, Robert G

    2017-03-08

    Highly pathogenic avian influenza (HPAI) H5N1 and low pathogenic avian influenza (LPAI) H9N2 viruses have been recognized as threats to public health in Bangladesh since 2007. Although live bird markets (LBMs) have been implicated in the transmission, dissemination, and circulation of these viruses, an in-depth analysis of the dynamics of avian transmission of H5N1 and H9N2 viruses at the human-animal interface has been lacking. Here we present and evaluate epidemiological findings from active surveillance conducted among poultry in various production sectors in Bangladesh from 2008 to 2016. Overall, the prevalence of avian influenza viruses (AIVs) in collected samples was 24%. Our data show that AIVs are more prevalent in domestic birds within LBMs (30.4%) than in farms (9.6%). Quail, chickens and ducks showed a high prevalence of AIVs (>20%). The vast majority of AIVs detected (99.7%) have come from apparently healthy birds and poultry drinking water served as a reservoir of AIVs with a prevalence of 32.5% in collected samples. HPAI H5N1 was more frequently detected in ducks while H9N2 was more common in chickens and quail. LBMs, particularly wholesale markets, have become a potential reservoir for various types of AIVs, including HPAI H5N1 and LPAI H9N2. The persistence of AIVs in LBMs is of great concern to public health, and this study highlights the importance of regularly reviewing and implementing infection control procedures as a means of reducing the exposure of the general public to AIVs.Emerging Microbes & Infections (2017) 6, e12; doi:10.1038/emi.2016.142; published online 8 March 2017.

  17. Prior infection of chickens with H1N1 or H1N2 avian influenza elicits partial heterologous protection against highly pathogenic H5N1.

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    Charles Nfon

    Full Text Available There is a critical need to have vaccines that can protect against emerging pandemic influenza viruses. Commonly used influenza vaccines are killed whole virus that protect against homologous and not heterologous virus. Using chickens we have explored the possibility of using live low pathogenic avian influenza (LPAI A/goose/AB/223/2005 H1N1 or A/WBS/MB/325/2006 H1N2 to induce immunity against heterologous highly pathogenic avian influenza (HPAI A/chicken/Vietnam/14/2005 H5N1. H1N1 and H1N2 replicated in chickens but did not cause clinical disease. Following infection, chickens developed nucleoprotein and H1 specific antibodies, and reduced H5N1 plaque size in vitro in the absence of H5 neutralizing antibodies at 21 days post infection (DPI. In addition, heterologous cell mediated immunity (CMI was demonstrated by antigen-specific proliferation and IFN-γ secretion in PBMCs re-stimulated with H5N1 antigen. Following H5N1 challenge of both pre-infected and naïve controls chickens housed together, all naïve chickens developed acute disease and died while H1N1 or H1N2 pre-infected chickens had reduced clinical disease and 70-80% survived. H1N1 or H1N2 pre-infected chickens were also challenged with H5N1 and naïve chickens placed in the same room one day later. All pre-infected birds were protected from H5N1 challenge but shed infectious virus to naïve contact chickens. However, disease onset, severity and mortality was reduced and delayed in the naïve contacts compared to directly inoculated naïve controls. These results indicate that prior infection with LPAI virus can generate heterologous protection against HPAI H5N1 in the absence of specific H5 antibody.

  18. Prior infection of chickens with H1N1 or H1N2 avian influenza elicits partial heterologous protection against highly pathogenic H5N1.

    Science.gov (United States)

    Nfon, Charles; Berhane, Yohannes; Pasick, John; Embury-Hyatt, Carissa; Kobinger, Gary; Kobasa, Darwyn; Babiuk, Shawn

    2012-01-01

    There is a critical need to have vaccines that can protect against emerging pandemic influenza viruses. Commonly used influenza vaccines are killed whole virus that protect against homologous and not heterologous virus. Using chickens we have explored the possibility of using live low pathogenic avian influenza (LPAI) A/goose/AB/223/2005 H1N1 or A/WBS/MB/325/2006 H1N2 to induce immunity against heterologous highly pathogenic avian influenza (HPAI) A/chicken/Vietnam/14/2005 H5N1. H1N1 and H1N2 replicated in chickens but did not cause clinical disease. Following infection, chickens developed nucleoprotein and H1 specific antibodies, and reduced H5N1 plaque size in vitro in the absence of H5 neutralizing antibodies at 21 days post infection (DPI). In addition, heterologous cell mediated immunity (CMI) was demonstrated by antigen-specific proliferation and IFN-γ secretion in PBMCs re-stimulated with H5N1 antigen. Following H5N1 challenge of both pre-infected and naïve controls chickens housed together, all naïve chickens developed acute disease and died while H1N1 or H1N2 pre-infected chickens had reduced clinical disease and 70-80% survived. H1N1 or H1N2 pre-infected chickens were also challenged with H5N1 and naïve chickens placed in the same room one day later. All pre-infected birds were protected from H5N1 challenge but shed infectious virus to naïve contact chickens. However, disease onset, severity and mortality was reduced and delayed in the naïve contacts compared to directly inoculated naïve controls. These results indicate that prior infection with LPAI virus can generate heterologous protection against HPAI H5N1 in the absence of specific H5 antibody.

  19. 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

  20. Prophylactic and therapeutic efficacy of avian antibodies against influenza virus H5N1 and H1N1 in mice.

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    Huan H Nguyen

    Full Text Available BACKGROUND: Pandemic influenza poses a serious threat to global health and the world economy. While vaccines are currently under development, passive immunization could offer an alternative strategy to prevent and treat influenza virus infection. Attempts to develop monoclonal antibodies (mAbs have been made. However, passive immunization based on mAbs may require a cocktail of mAbs with broader specificity in order to provide full protection since mAbs are generally specific for single epitopes. Chicken immunoglobulins (IgY found in egg yolk have been used mainly for treatment of infectious diseases of the gastrointestinal tract. Because the recent epidemic of highly pathogenic avian influenza virus (HPAIV strain H5N1 has resulted in serious economic losses to the poultry industry, many countries including Vietnam have introduced mass vaccination of poultry with H5N1 virus vaccines. We reasoned that IgY from consumable eggs available in supermarkets in Vietnam could provide protection against infections with HPAIV H5N1. METHODS AND FINDINGS: We found that H5N1-specific IgY that are prepared from eggs available in supermarkets in Vietnam by a rapid and simple water dilution method cross-protect against infections with HPAIV H5N1 and related H5N2 strains in mice. When administered intranasally before or after lethal infection, the IgY prevent the infection or significantly reduce viral replication resulting in complete recovery from the disease, respectively. We further generated H1N1 virus-specific IgY by immunization of hens with inactivated H1N1 A/PR/8/34 as a model virus for the current pandemic H1N1/09 and found that such H1N1-specific IgY protect mice from lethal influenza virus infection. CONCLUSIONS: The findings suggest that readily available H5N1-specific IgY offer an enormous source of valuable biological material to combat a potential H5N1 pandemic. In addition, our study provides a proof-of-concept for the approach using virus

  1. Histopathologic study of avian influenza H5N1 infection in humans%人感染高致病性禽流感病毒H5N1的病理学观察

    Institute of Scientific and Technical Information of China (English)

    陆敏; 谢志刚; 高占成; 王辰; 李宁; 李敏; 邵宏权; 王玉萍; 高子芬

    2008-01-01

    目的 观察人感染高致病性禽流感病毒H5N1后各主要脏器的病理改变.方法 按传染病尸体解剖要求对2例死亡病例系统解剖,并获得心、肝、脾、肺和肾等主要脏器,对1例重症患者行肺大泡切除术,组织常规HE和免疫组织化学染色,光学显微镜下观察.结果 2例肺组织主要呈弥漫性肺泡损伤改变.早期呈渗出性改变,肺泡上皮坏死脱落,肺泡腔内见大量均匀粉染渗出液伴广泛透明膜形成.中晚期主要呈增生性和纤维化性改变,肺泡上皮和支气管上皮增生,肺泡腔内渗出物和肺间质纤维化.1例在慢性支气管扩张症基础上伴弥漫性肺泡损伤和肺间质纤维化.免疫器官改变:全身淋巴组织萎缩伴活跃的噬血现象.其他脏器病变:1例心脏有间质性心肌炎;1例肾脏有急性肾小管坏死;1例有脑水肿伴脑实质内神经细胞嗜酸性变,轴突肿胀,粗细不均.脑室旁见灶状坏死.1例孕妇胎盘内多灶状滋养叶细胞坏死伴营养不良性钙化,有急性坏死性蜕膜炎.胚胎肺脏有肺水肿和肺炎改变.结论 人感染高致病性禽流感病毒H5N1后首先出现呼吸系统症状,广泛弥漫性肺泡损伤致低氧血症是病理学基础,患者最终因多器官功能衰竭致呼吸、循环衰竭死亡.%Objective To identify histopathologic changes of major organs and to correlate clinical symptoms in patients infected by avian influenza H5N1.Methods Autopsy study was performed in two patients died of avian influenza H5N1 infection,following conventional protocols and strict safety procedures.Tissue samples from all major organs of two cases and lung samples of one case were collected and fixed in 4% formaldehyde.Histopathologic changes were evaluated by light microscope.Results Diffuse alveolar damage (DAD) of the lung was seen in both cases.Lesions at various stages of development were seen involving different areas of the lung.At the early stages,the lungs exhibited

  2. 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.

  3. 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.

  4. 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.

  5. 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....

  6. 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...

  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. Eco-virological approach for assessing the role of wild birds in the spread of avian influenza H5N1 along the central Asian flyway

    Science.gov (United States)

    Newman, Scott H.; Hill, Nichola J.; Spragens, Kyle A.; Janies, Daniel; Voronkin, Igor O.; Prosser, Diann J.; Yan, Baoping; Lei, Fumin; Batbayar, Nyambayar; Natsagdorj, Tseveenmyadag; Bishop, Charles M.; Butler, Patrick J.; Wikelski, Martin; Balachandran, Sivananinthaperumal; Mundkur, Taej; Douglas, David C.; Takekawa, John Y.

    2012-01-01

    A unique pattern of highly pathogenic avian influenza (HPAI) H5N1 outbreaks has emerged along the Central Asia Flyway, where infection of wild birds has been reported with steady frequency since 2005. We assessed the potential for two hosts of HPAI H5N1, the bar-headed goose (Anser indicus) and ruddy shelduck (Tadorna tadorna), to act as agents for virus dispersal along this ‘thoroughfare’. We used an eco-virological approach to compare the migration of 141 birds marked with GPS satellite transmitters during 2005–2010 with: 1) the spatio-temporal patterns of poultry and wild bird outbreaks of HPAI H5N1, and 2) the trajectory of the virus in the outbreak region based on phylogeographic mapping. We found that biweekly utilization distributions (UDs) for 19.2% of bar-headed geese and 46.2% of ruddy shelduck were significantly associated with outbreaks. Ruddy shelduck showed highest correlation with poultry outbreaks owing to their wintering distribution in South Asia, where there is considerable opportunity for HPAI H5N1 spillover from poultry. Both species showed correlation with wild bird outbreaks during the spring migration, suggesting they may be involved in the northward movement of the virus. However, phylogeographic mapping of HPAI H5N1 clades 2.2 and 2.3 did not support dissemination of the virus in a northern direction along the migration corridor. In particular, two subclades (2.2.1 and 2.3.2) moved in a strictly southern direction in contrast to our spatio-temporal analysis of bird migration. Our attempt to reconcile the disciplines of wild bird ecology and HPAI H5N1 virology highlights prospects offered by both approaches as well as their limitations.

  9. VARIATION OF NON-CODING REGION AND CODING REGION OF 5’-TERMINAL CRNA OF POLYMERASE BASIC 1 OF AVIAN INFLUENZA VIRUS SUBTYPE H5N1

    Directory of Open Access Journals (Sweden)

    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

  10. 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.

  11. 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.

  12. 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.

  13. Risk assessment of the introduction of H5N1 highly pathogenic avian influenza as a tool to be applied in prevention strategy plan.

    Science.gov (United States)

    Corbellini, L G; Pellegrini, D C P; Dias, R A; Reckziegel, A; Todeschini, B; Bencke, G A

    2012-04-01

    Risks of the introduction of highly pathogenic avian influenza (HPAI) H5N1 through migratory birds to the main wintering site for wild birds in southern Brazil and its consequences were assessed. Likelihoods were estimated by a qualitative scale ranging from negligible to high. Northern migrants that breed in Alaska and regularly migrate to South America (primary Charadriiformes) can have contact with birds from affected areas in Asia. The likelihood of the introduction of HPAI H5N1 through migratory birds was found to be very low as it is a probability conditioned to successful transmission in breeding areas and the probabilities of an infected bird migrating and shedding the virus as far as southern Brazil. The probability of wild species becoming exposed to H5N1-infected birds is high as they nest with northern migrants from Alaska, whereas for backyard poultry it is moderate to high depending on proximity to wetlands and the presence of species that could increase the likelihood of contact with wild birds such as domestic duck. The magnitude of the biological and economic consequences of successful transmission to poultry or wild birds would be low to severe depending on the probability of the occurrence of outbreak scenarios described. As a result, the risk estimate is greater than negligible, and HPAI H5N1 prevention strategy in the region should always be carefully considered by the veterinary services in Brazil.

  14. Migratory movements of waterfowl in Central Asia and avian influenza emergence: sporadic transmission of H5N1 from east to west

    Science.gov (United States)

    Iverson, Samuel A.; Gavrilov, Andrei; Katzner, Todd E.; Takekawa, John Y.; Miller, Tricia A.; Hagemeijer, Ward; Mundkur, Taej; Sivananinthaperumal, Balachandran; DeMattos, Carlos C.; Ahmed, Lu'ay S.; Newman, Scott H.

    2011-01-01

    Waterfowl in the genera Anas and Tadorna are suspected as vectors in the long-distance transmission of highly pathogenic avian influenza H5N1. The former Soviet Republics of Central Asia are situated at an important migratory crossroads for these and other species of birds that bridges regions where the disease is prevalent. However, waterfowl movements through Central Asia are poorly quantified. In this study, historical data derived from over 80 years of bird ringing are combined with recent satellite tracking data to delineate migration routes, movement chronology and habitat use patterns of waterfowl in relation to H5N1 outbreak locations. Results confirm migratory linkage between breeding and moulting areas in northern Kazakhstan and southern Siberia, with nonbreeding areas in the Caspian, Black and eastern Mediterranean Sea basins, as well as with South Asia. However, unlike the situation in neighbouring regions, most notably western China, H5N1 outbreaks have not been recurrent in Central Asia after they were first reported during summer 2005 and spring 2006. These findings have implications in relation to potential sampling biases, species-specific variation in migratory behaviour and continuing regional H5N1 transmission risks.

  15. H5N1亚型禽流感病毒NS1蛋白研究进展%The research progress of H5N1 subtype avian influenza virus NS1 protein

    Institute of Scientific and Technical Information of China (English)

    李观强; 李国明; 张志珍

    2011-01-01

    @@ 禽流感(avian influenza ,AI) 为A型流感病毒(avian influenza virus ,AIV)引起的禽类流行性感冒.根据是否引起流感及症状的不同,通常将禽流感分为高致病性(highly pathogenic avian influenza,HPAI)、低致病性(low pathogenic avian influenza,LPAI) 和非致病性禽流感(no pathogenic avian influenza,NPAI).

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

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    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.

  17. Preclinical and clinical development of plant-made virus-like particle vaccine against avian H5N1 influenza.

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    Nathalie Landry

    Full Text Available UNLABELLED: The recent swine H1N1 influenza outbreak demonstrated that egg-based vaccine manufacturing has an Achille's heel: its inability to provide a large number of doses quickly. Using a novel manufacturing platform based on transient expression of influenza surface glycoproteins in Nicotiana benthamiana, we have recently demonstrated that a candidate Virus-Like Particle (VLP vaccine can be generated within 3 weeks of release of sequence information. Herein we report that alum-adjuvanted plant-made VLPs containing the hemagglutinin (HA protein of H5N1 influenza (A/Indonesia/5/05 can induce cross-reactive antibodies in ferrets. Even low doses of this vaccine prevented pathology and reduced viral loads following heterotypic lethal challenge. We further report on safety and immunogenicity from a Phase I clinical study of the plant-made H5 VLP vaccine in healthy adults 18-60 years of age who received 2 doses 21 days apart of 5, 10 or 20 µg of alum-adjuvanted H5 VLP vaccine or placebo (alum. The vaccine was well tolerated at all doses. Adverse events (AE were mild-to-moderate and self-limited. Pain at the injection site was the most frequent AE, reported in 70% of vaccinated subjects versus 50% of the placebo recipients. No allergic reactions were reported and the plant-made vaccine did not significantly increase the level of naturally occurring serum antibodies to plant-specific sugar moieties. The immunogenicity of the H5 VLP vaccine was evaluated by Hemagglutination-Inhibition (HI, Single Radial Hemolysis (SRH and MicroNeutralisation (MN. Results from these three assays were highly correlated and showed similar trends across doses. There was a clear dose-response in all measures of immunogenicity and almost 96% of those in the higher dose groups (2 × 10 or 20 µg mounted detectable MN responses. Evidence of striking cross-protection in ferrets combined with a good safety profile and promising immunogenicity in humans suggest that plant

  18. 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

  19. 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.

  20. Spatial modeling of wild bird risk factors to investigate highly pathogenic A(H5N1) avian influenza virus transmission

    Science.gov (United States)

    Prosser, Diann J.; Hungerford, Laura L.; Erwin, R. Michael; Ottinger, Mary Ann; Takekawa, John Y.; Newman, Scott H.; Xiao, Xianming; Ellis, Erie C.

    2016-01-01

    One of the longest-persisting avian influenza viruses in history, highly pathogenic avian influenza virus (HPAIV) A(H5N1), continues to evolve after 18 years, advancing the threat of a global pandemic. Wild waterfowl (family Anatidae), are reported as secondary transmitters of HPAIV, and primary reservoirs for low-pathogenic avian influenza viruses, yet spatial inputs for disease risk modeling for this group have been lacking. Using GIS and Monte Carlo simulations, we developed geospatial indices of waterfowl abundance at 1 and 30 km resolutions and for the breeding and wintering seasons for China, the epicenter of H5N1. Two spatial layers were developed: cumulative waterfowl abundance (WAB), a measure of predicted abundance across species, and cumulative abundance weighted by H5N1 prevalence (WPR), whereby abundance for each species was adjusted based on prevalence values then totaled across species. Spatial patterns of the model output differed between seasons, with higher WAB and WPR in the northern and western regions of China for the breeding season and in the southeast for the wintering season. Uncertainty measures indicated highest error in southeastern China for both WAB and WPR. We also explored the effect of resampling waterfowl layers from 1 km to 30 km resolution for multi-scale risk modeling. Results indicated low average difference (less than 0.16 and 0.01 standard deviations for WAB and WPR, respectively), with greatest differences in the north for the breeding season and southeast for the wintering season. This work provides the first geospatial models of waterfowl abundance available for China. The indices provide important inputs for modeling disease transmission risk at the interface of poultry and wild birds. These models are easily adaptable, have broad utility to both disease and conservation needs, and will be available to the scientific community for advanced modeling applications.

  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.

  2. Detection of antibody responses by using haemagglutination inhibiton test and the protection titer of avian influenza virus H5N1 subtype

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    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.

  3. 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 ...

  4. Expression of hemagglutinin protein from the avian influenza virus H5N1 in a baculovirus/insect cell system significantly enhanced by suspension culture

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    Spencer Lynn

    2006-02-01

    Full Text Available Abstract Background Prevention of a possible avian influenza pandemic necessitates the development of rapid diagnostic tests and the eventual production of a vaccine. Results For vaccine production, hemagglutinin (HA1 from avian influenza H5N1 was expressed from a recombinant baculovirus. Recombinant HA1 was expressed in monolayer or suspension culture insect cells by infection with the recombinant baculovirus. The yield of rHA1 from the suspension culture was 68 mg/l, compared to 6 mg/l from the monolayer culture. Immunization of guinea pigs with 50 μg of rHA1 yielded hemagglutinin inhibition and virus neutralization titers of 1:160 after two times vaccination with rHA1 protein. Conclusion Thus, the production of rHA1 using an insect suspension cell system provides a promising basis for economical production of a H5 antigen.

  5. 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.

  6. Potential spread of highly pathogenic avian influenza H5N1 by wildfowl: dispersal ranges and rates determined from large-scale satellite telemetry

    Science.gov (United States)

    Gaidet, Nicolas; Cappelle, Julien; Takekawa, John Y.; Prosser, Diann J.; Iverson, Samuel A.; Douglas, David C.; Perry, William M.; Mundkur, Taej; Newman, Scott H.

    2010-01-01

    1. Migratory birds are major candidates for long-distance dispersal of zoonotic pathogens. In recent years, wildfowl have been suspected of contributing to the rapid geographic spread of the highly pathogenic avian influenza (HPAI) H5N1 virus. Experimental infection studies reveal that some wild ducks, geese and swans shed this virus asymptomatically and hence have the potential to spread it as they move. 2. We evaluate the dispersive potential of HPAI H5N1 viruses by wildfowl through an analysis of the movement range and movement rate of birds monitored by satellite telemetry in relation to the apparent asymptomatic infection duration (AID) measured in experimental studies. We analysed the first large-scale data set of wildfowl movements, including 228 birds from 19 species monitored by satellite telemetry in 2006–2009, over HPAI H5N1 affected regions of Asia, Europe and Africa. 3. Our results indicate that individual migratory wildfowl have the potential to disperse HPAI H5N1 over extensive distances, being able to perform movements of up to 2900 km within timeframes compatible with the duration of asymptomatic infection. 4. However, the likelihood of such virus dispersal over long distances by individual wildfowl is low: we estimate that for an individual migratory bird there are, on average, only 5–15 days per year when infection could result in the dispersal of HPAI H5N1 virus over 500 km. 5. Staging at stopover sites during migration is typically longer than the period of infection and viral shedding, preventing birds from dispersing a virus over several consecutive but interrupted long-distance movements. Intercontinental virus dispersion would therefore probably require relay transmission between a series of successively infected migratory birds. 6. Synthesis and applications. Our results provide a detailed quantitative assessment of the dispersive potential of HPAI H5N1 virus by selected migratory birds. Such dispersive potential rests on the

  7. Optimizing early detection of avian influenza H5N1 in backyard and free-range poultry production systems in Thailand.

    Science.gov (United States)

    Goutard, Flavie L; Paul, Mathilde; Tavornpanich, Saraya; Houisse, Ivan; Chanachai, Karoon; Thanapongtharm, Weerapong; Cameron, Angus; Stärk, Katharina D C; Roger, François

    2012-07-01

    For infectious diseases such as highly pathogenic avian influenza caused by the H5N1 virus (A/H5N1 HP), early warning system is essential. Evaluating the sensitivity of surveillance is a necessary step in ensuring an efficient and sustainable system. Stochastic scenario tree modeling was used here to assess the sensitivity of the A/H5N1 HP surveillance system in backyard and free-grazing duck farms in Thailand. The whole surveillance system for disease detection was modeled with all components and the sensitivity of each component and of the overall system was estimated. Scenarios were tested according to selection of high-risk areas, inclusion of components and sampling procedure, were tested. Nationwide passive surveillance (SSC1) and risk-based clinical X-ray (SSC2) showed a similar sensitivity level, with a median sensitivity ratio of 0.96 (95% CI 0.40-15.00). They both provide higher sensitivity than the X-ray laboratory component (SSC3). With the current surveillance design, the sensitivity of detection of the overall surveillance system when the three components are implemented, was equal to 100% for a farm level prevalence of 0.05% and 82% (95% CI 71-89%) for a level of infection of 3 farms. Findings from this study illustrate the usefulness of scenario-tree modeling to document freedom from diseases in developing countries.

  8. Agro-ecological features of the introduction and spread of the highly pathogenic avian influenza (HPAI H5N1 in northern Nigeria

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    Giuliano Cecchi

    2008-11-01

    Full Text Available Nigeria was the first African country to report highly pathogenic avian influenza (HPAI H5N1 virus outbreaks in February 2006 and has since been the most severely hit country in sub-Saharan Africa. A retrospective survey carried out towards the end of 2007, coupled with follow-up spatial analysis, support the notion that the H5N1 virus may have spread from rural areas of northern Nigeria near wetlands frequented by palaearctic migratory birds. Possibly, this could have happened already during November to December 2005, one or two months prior to the first officially reported outbreak in a commercial poultry farm (Kaduna state. It is plausible that backyard poultry played a more important role in the H5N1 propagation than thought previously. Farming landscapes with significant numbers of domestic ducks may have helped to bridge the geographical and ecological gap between the waterfowl in the wetlands and the densely populated poultry rich states in north-central Nigeria, where the virus had more sizeable, visible impact.

  9. Experimental infection of mandarin duck with highly pathogenic avian influenza A (H5N8 and H5N1) viruses.

    Science.gov (United States)

    Kang, Hyun-Mi; Lee, Eun-Kyoung; Song, Byung-Min; Heo, Gyeong-Beom; Jung, Joojin; Jang, Il; Bae, You-Chan; Jung, Suk Chan; Lee, Youn-Jeong

    2017-01-01

    A highly pathogenic avian influenza (HPAI) H5N8 virus was first detected in poultry and wild birds in South Korea in January 2014. Here, we determined the pathogenicity and transmissibility of three different clades of H5 viruses in mandarin ducks to examine the potential for wild bird infection. H5N8 (clade 2.3.4.4) replicated more efficiently in the upper and lower respiratory tract of mandarin ducks than two previously identified H5N1 virus clades (clades 2.2 and 2.3.2.1). However, none of the mandarin ducks infected with H5N8 and H5N1 viruses showed severe clinical signs or mortality, and gross lesions were only observed in a few tissues. Viral replication and shedding were greater in H5N8-infected ducks than in H5N1-infected ducks. Recovery of all viruses from control duck in contact with infected ducks indicated that the highly pathogenic H5 viruses spread horizontally through contact. Taken together, these results suggest that H5N8 viruses spread efficiently in mandarin ducks. Further studies of pathogenicity in wild birds are required to examine possible long-distance dissemination via migration routes.

  10. 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.

  11. Impact of the implementation of rest days in live bird markets on the dynamics of H5N1 highly pathogenic avian influenza.

    Science.gov (United States)

    Fournié, G; Guitian, F J; Mangtani, P; Ghani, A C

    2011-08-01

    Live bird markets (LBMs) act as a network 'hub' and potential reservoir of infection for domestic poultry. They may therefore be responsible for sustaining H5N1 highly pathogenic avian influenza (HPAI) virus circulation within the poultry sector, and thus a suitable target for implementing control strategies. We developed a stochastic transmission model to understand how market functioning impacts on the transmission dynamics. We then investigated the potential for rest days-periods during which markets are emptied and disinfected-to modulate the dynamics of H5N1 HPAI within the poultry sector using a stochastic meta-population model. Our results suggest that under plausible parameter scenarios, HPAI H5N1 could be sustained silently within LBMs with the time spent by poultry in markets and the frequency of introduction of new susceptible birds' dominant factors determining sustained silent spread. Compared with interventions applied in farms (i.e. stamping out, vaccination), our model shows that frequent rest days are an effective means to reduce HPAI transmission. Furthermore, our model predicts that full market closure would be only slightly more effective than rest days to reduce transmission. Strategies applied within markets could thus help to control transmission of the disease.

  12. Pathology of a H5N1, highly pathogenic avian influenza virus, in two Indian native chicken breeds and a synthetic broiler line.

    Science.gov (United States)

    Suba, S; Nagarajan, S; Saxena, V K; Kumar, M; Vanamayya, P R; Rajukumar, K; Gowthaman, V; Jain, V; Singh, D P; Dubey, S C

    2015-04-01

    In this study, susceptibility to H5N1 virus infection was studied in two Indian native chicken breeds viz. Kadaknath and Aseel (Peela) and an Indian synthetic broiler strain (Synthetic dam line (SDL-IC). Fifty birds from each genetic group were infected intra-nasally with 1000 EID50 of a highly pathogenic avian influenza virus (HPAIV) strain A/chicken/Navapur/India/7972/ 06 (H5N1) and observed for a period of 10 days. Significant differences in severity of clinical signs, gross lesions and time for onset of symptoms were observed. The overall severity of clinical signs and gross lesions was less in SDL-IC broilers as compared to the other two genetic groups. The mortality percentages were 100, 98 and 92% with Mean Death Time (MDT) of 3.12, 5.92 and 6.96 days, respectively for the two native breeds Kadaknath and Aseel (Peela), the and SDL-IC broiler strain. Comparison of histological lesions revealed differences in disease progression among the genetic groups. Vascular lesions such as disseminated intravascular coagulopathy (DIC) were predominant on 3 days post infection (dpi) in Kadaknath, and on 5 and 6 dpi in Aseel (Peela) and SDL-IC broiler. The mean log2 HA titres of the re-isolated virus from various organs of H5N1 AIV infected birds of the three genetic groups ranged from 2.32 (lung, trachea and bursa) to 5.04 (spleen) in Kadaknath; 2.32 (lung) to 6.68 (brain) in Aseel (Peela); and 2.06 (liver) to 7.01 (lungs and kidney) in SDL-IC broiler. These results suggest that the susceptibility to H5N1 highly pathogenic avian influenza virus infection differed among the three breeds; Kadaknath being highest followed by Aseel (Peela) and synthetic SDL-IC broiler. This is possibly the first report on the differences in the susceptibility of the India native breeds to H5N1 virus infection and its severity.

  13. Vaccination with Astragalus and Ginseng Polysaccharides Improves Immune Response of Chickens against H5N1 Avian Influenza Virus

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    Auwalu Yusuf Abdullahi

    2016-01-01

    Full Text Available To determine the effect of astragalus and ginseng polysaccharides (APS, GPS on immune response and improvement of H5N1 vaccine, 360-day-old broilers were randomly divided into 8 groups of 45 chicks, comprising APS groups (1–3; GPS groups (4–6; vaccine group (7; and blank control (8 (without polysaccharide and vaccine. From day 12 after hatch groups 1–3 were given APS and groups 4–6 with GPS both at 100, 200, and 400 (mg/kg, respectively. At day 15 after hatch, groups 1–7 were vaccinated with 0.3 mL H5N1 vaccine subcutaneously; daily weight gain (DWG and serum Ig antibody (by HI-test were measured on 3, 7, 14, and 28 days after vaccination. Serum antibody titers and expression of cytokines (IL-2, IL-10, I FN-γ, and TNF were determined by ELISA and RT-PCR. Results revealed that all the polysaccharide groups were numerically increased in antibody levels and the expression of cytokines was significant (P<0.05 in the APS and GPS groups compared to corresponding vaccine group and blank control. DWG was higher (P<0.05 in 400 mg/kg APS groups than control groups. Thus oral supplements of GPS and APS have shown their potential in the improvement of immune response and could be used as adjuvant in a formulation of H5N1 vaccine.

  14. A novel hemagglutinin protein produced in bacteria protects chickens against H5N1 highly pathogenic avian influenza viruses by inducing H5 subtype-specific neutralizing antibodies

    Science.gov (United States)

    Sączyńska, Violetta; Romanik, Agnieszka; Florys, Katarzyna; Cecuda-Adamczewska, Violetta; Kęsik-Brodacka, Małgorzata; Śmietanka, Krzysztof; Olszewska, Monika; Domańska-Blicharz, Katarzyna; Minta, Zenon; Szewczyk, Bogusław; Płucienniczak, Grażyna; Płucienniczak, Andrzej

    2017-01-01

    The highly pathogenic (HP) H5N1 avian influenza viruses (AIVs) cause a mortality rate of up to 100% in infected chickens and pose a permanent pandemic threat. Attempts to obtain effective vaccines against H5N1 HPAIVs have focused on hemagglutinin (HA), an immunodominant viral antigen capable of eliciting neutralizing antibodies. The vast majority of vaccine projects have been performed using eukaryotic expression systems. In contrast, we used a bacterial expression system to produce vaccine HA protein (bacterial HA) according to our own design. The HA protein with the sequence of the H5N1 HPAIV strain was efficiently expressed in Escherichia coli, recovered in the form of inclusion bodies and refolded by dilution between two chromatographic purification steps. Antigenicity studies showed that the resulting antigen, referred to as rH5-E. coli, preserves conformational epitopes targeted by antibodies specific for H5-subtype HAs, inhibiting hemagglutination and/or neutralizing influenza viruses in vitro. The proper conformation of this protein and its ability to form functional oligomers were confirmed by a hemagglutination test. Consistent with the biochemical characteristics, prime-boost immunizations with adjuvanted rH5-E. coli protected 100% and 70% of specific pathogen-free, layer-type chickens against challenge with homologous and heterologous H5N1 HPAIVs, respectively. The observed protection was related to the positivity in the FluAC H5 test (IDVet) but not to hemagglutination-inhibiting antibody titers. Due to full protection, the effective contact transmission of the homologous challenge virus did not occur. Survivors from both challenges did not or only transiently shed the viruses, as established by viral RNA detection in oropharyngeal and cloacal swabs. Our results demonstrate that vaccination with rH5-E. coli could confer control of H5N1 HPAIV infection and transmission rates in chicken flocks, accompanied by reduced virus shedding. Moreover, the role of

  15. Rivers and flooded areas identified by medium-resolution remote sensing improve risk prediction of the highly pathogenic avian influenza H5N1 in Thailand

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    Weerapong Thanapongtharm

    2013-11-01

    Full Text Available Thailand experienced several epidemic waves of the highly pathogenic avian influenza (HPAI H5N1 between 2004 and 2005. This study investigated the role of water in the landscape, which has not been previously assessed because of a lack of high-resolution information on the distribution of flooded land at the time of the epidemic. Nine Landsat 7- Enhanced Thematic Mapper Plus scenes covering 174,610 km2 were processed using k-means unsupervised classification to map the distribution of flooded areas as well as permanent lakes and reservoirs at the time of the main epidemic HPAI H5N1 wave of October 2004. These variables, together with other factors previously identified as significantly associated with risk, were entered into an autologistic regression model in order to quantify the gain in risk explanation over previously published models. We found that, in addition to other factors previously identified as associated with risk, the proportion of land covered by flooding along with expansion of rivers and streams, derived from an existing, sub-district level (administrative level no. 3 geographical information system database, was a highly significant risk factor in this 2004 HPAI epidemic. These results suggest that water-borne transmission could have partly contributed to the spread of HPAI H5N1 during the epidemic. Future work stemming from these results should involve studies where the actual distribution of small canals, rivers, ponds, rice paddy fields and farms are mapped and tested against farm-level data with respect to HPAI H5N1.

  16. Rivers and flooded areas identified by medium-resolution remote sensing improve risk prediction of the highly pathogenic avian influenza H5N1 in Thailand.

    Science.gov (United States)

    Thanapongtharm, Weerapong; Van Boeckel, Thomas P; Biradar, Chandrashekhar; Xiao, Xiang-Ming; Gilbert, Marius

    2013-11-01

    Thailand experienced several epidemic waves of the highly pathogenic avian influenza (HPAI) H5N1 between 2004 and 2005. This study investigated the role of water in the landscape, which has not been previously assessed because of a lack of high-resolution information on the distribution of flooded land at the time of the epidemic. Nine Landsat 7 - Enhanced Thematic Mapper Plus scenes covering 174,610 km(2) were processed using k-means unsupervised classification to map the distribution of flooded areas as well as permanent lakes and reservoirs at the time of the main epidemic HPAI H5N1 wave of October 2004. These variables, together with other factors previously identified as significantly associated with risk, were entered into an autologistic regression model in order to quantify the gain in risk explanation over previously published models. We found that, in addition to other factors previously identified as associated with risk, the proportion of land covered by flooding along with expansion of rivers and streams, derived from an existing, sub-district level (administrative level no. 3) geographical information system database, was a highly significant risk factor in this 2004 HPAI epidemic. These results suggest that water-borne transmission could have partly contributed to the spread of HPAI H5N1 during the epidemic. Future work stemming from these results should involve studies where the actual distribution of small canals, rivers, ponds, rice paddy fields and farms are mapped and tested against farm-level data with respect to HPAI H5N1.

  17. Anthropogenic factors and the risk of highly pathogenic avian influenza H5N1: prospects from a spatial-based model.

    Science.gov (United States)

    Paul, Mathilde; Tavornpanich, Saraya; Abrial, David; Gasqui, Patrick; Charras-Garrido, Myriam; Thanapongtharm, Weerapong; Xiao, Xiangming; Gilbert, Marius; Roger, Francois; Ducrot, Christian

    2010-01-01

    Beginning in 2003, highly pathogenic avian influenza (HPAI) H5N1 virus spread across Southeast Asia, causing unprecedented epidemics. Thailand was massively infected in 2004 and 2005 and continues today to experience sporadic outbreaks. While research findings suggest that the spread of HPAI H5N1 is influenced primarily by trade patterns, identifying the anthropogenic risk factors involved remains a challenge. In this study, we investigated which anthropogenic factors played a role in the risk of HPAI in Thailand using outbreak data from the "second wave" of the epidemic (3 July 2004 to 5 May 2005) in the country. We first performed a spatial analysis of the relative risk of HPAI H5N1 at the subdistrict level based on a hierarchical Bayesian model. We observed a strong spatial heterogeneity of the relative risk. We then tested a set of potential risk factors in a multivariable linear model. The results confirmed the role of free-grazing ducks and rice-cropping intensity but showed a weak association with fighting cock density. The results also revealed a set of anthropogenic factors significantly linked with the risk of HPAI. High risk was associated strongly with densely populated areas, short distances to a highway junction, and short distances to large cities. These findings highlight a new explanatory pattern for the risk of HPAI and indicate that, in addition to agro-environmental factors, anthropogenic factors play an important role in the spread of H5N1. To limit the spread of future outbreaks, efforts to control the movement of poultry products must be sustained.

  18. Electrochemical detection of avian influenza virus H5N1 gene sequence using a DNA aptamer immobilized onto a hybrid nanomaterial-modified electrode

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xianggang [College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, Shandong (China); Cheng Ziqiang, E-mail: czqsd@126.com [College of Animal Science and Technology, Shandong Agricultural University, Taian 271018, Shandong (China); Fan Hai [College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, Shandong (China); Ai Shiyun, E-mail: ashy@sdau.edu.cn [College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, Shandong (China); Han Ruixia [College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, Shandong (China)

    2011-07-15

    Highlights: > A sensitive electrochemical biosensor for the detection of gene sequence was developed. > The biosensor was assembled by MWNT, polypyrrole nanowires and gold nanoparticles. > The hybrid nanomaterials could provide a porous structure with good properties. > The biosensor has highly selectivity and sensitivity. > The design strategy is expected to have extensive applications in other biosensors - Abstract: A sensitive electrochemical method for the detection of avian influenza virus (AIV) H5N1 gene sequence using a DNA aptamer immobilized onto a hybrid nanomaterial-modified electrode was developed. To enhance the selectivity and sensitivity, the modified electrode was assembled with multi-wall carbon nanotubes (MWNT), polypyrrole nanowires (PPNWs) and gold nanoparticles (GNPs). This electrode offered a porous structure with a large effective surface area, highly electrocatalytic activities and electronic conductivity. Therefore, the amount of DNA aptamer immobilized onto the electrode was increased while the accessibility of the detection target was maintained. The biosensor is based on the hybridization and preferred orientation of a DNA aptamer immobilized onto a modified electrode surface with its target (H5N1 specific sequence) present in solution. It is selective for the H5N1 specific sequence, and the signal of the indicator was approximately linear to log(concentration) of the H5N1 specific sequence from 5.0 x 10{sup -12} to 1.0 x 10{sup -9} M (R = 0.9863) with a detection limit of 4.3 x 10{sup -13} M. These studies showed that the new hybrid nanomaterial (MWNT/PPNWs/GNPs) and the DNA aptamer could be used to fabricate an electrochemical biosensor for gene sequence detection. Furthermore, this design strategy is expected to have extensive applications in other biosensors.

  19. 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

  20. 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

    200 km and within 14 days of each other. This might indicate long distance dispersal through vectors such as migratory birds and vehicles, and challenges the effectiveness of movement restriction around 10 km radius of an outbreak. The study indicates possible endemicity of the clade 2.2 HPAI-H5N1...... virus in Bangladesh. Furthermore, the formation of a subclade capable of transmission to humans cannot be ruled out. The findings of this study might provide valuable information for future surveillance, prevention and control programme....

  1. 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.

  2. 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.

  3. Different routes of inoculation impact infectivity and pathogenesis of H5N1 high pathogenicity avian influenza virus infection in chickens and domestic ducks.

    Science.gov (United States)

    Kwon, Y K; Swayne, D E

    2010-12-01

    The H5N1 type A influenza viruses classified as Qinghai-like virus (clade 2.2) are a unique lineage of type A influenza viruses with the capacity to produce significant disease and mortality in gallinaceous and anseriform birds, including domestic and wild ducks. The objective of this study was to determine the susceptibility and pathogenesis of chickens and domestic ducks to A/Whooper Swan/Mongolia/224/05 (H5N1) high pathogenicity avian influenza (HPAI) virus when administered through respiratory or alimentary routes of exposure. The chickens and ducks were more susceptible to the H5N1 HPAI virus, as evidenced by low infectious and lethal viral doses, when exposed by intranasal as compared to alimentary routes of inoculation (intragastric or oral-fed infected chicken meat). In the alimentary exposure pathogenesis study, pathologic changes included hemorrhage, necrosis, and inflammation in association with virus detection. These changes were generally observed in most of the visceral organs of chickens, between 2 and 4 days postinoculation (DPI), and are similar to lesions and virus localization seen in birds in natural cases or in experimental studies using the intranasal route. Alimentary exposure to the virus caused systemic infection in the ducks, characterized by moderate lymphocytic encephalitis, necrotized hepatitis, and pancreatitis with a corresponding demonstration of virus within the lesions. In both chickens and ducks with alimentary exposure, lesions, virus, or both were first demonstrated in the upper alimentary tract on 1 DPI, suggesting that the alimentary tract was the initial site affected upon consumption of infected meat or on gavage of virus in liquid medium. However, as demonstrated in the infectivity study in chickens, alimentary infection required higher exposure doses to produce infection as compared to intranasal exposure in chickens. These data suggest that upper respiratory exposure to H5N1 HPAI virus in birds is more likely to result in

  4. High-Yield Expression of M2e Peptide of Avian Influenza Virus H5N1 in Transgenic Duckweed Plants.

    Science.gov (United States)

    Firsov, Aleksey; Tarasenko, Irina; Mitiouchkina, Tatiana; Ismailova, Natalya; Shaloiko, Lyubov; Vainstein, Alexander; Dolgov, Sergey

    2015-07-01

    Avian influenza is a major viral disease in poultry. Antigenic variation of this virus hinders vaccine development. However, the extracellular domain of the virus-encoded M2 protein (peptide M2e) is nearly invariant in all influenza A strains, enabling the development of a broad-range vaccine against them. Antigen expression in transgenic plants is becoming a popular alternative to classical expression methods. Here we expressed M2e from avian influenza virus A/chicken/Kurgan/5/2005(H5N1) in nuclear-transformed duckweed plants for further development of avian influenza vaccine. The N-terminal fragment of M2, including M2e, was selected for expression. The M2e DNA sequence fused in-frame to the 5' end of β-glucuronidase was cloned into pBI121 under the control of CaMV 35S promoter. The resulting plasmid was successfully used for duckweed transformation, and western analysis with anti-β-glucuronidase and anti-M2e antibodies confirmed accumulation of the target protein (M130) in 17 independent transgenic lines. Quantitative ELISA of crude protein extracts from these lines showed M130-β-glucuronidase accumulation ranging from 0.09-0.97 mg/g FW (0.12-1.96 % of total soluble protein), equivalent to yields of up to 40 μg M2e/g plant FW. This relatively high yield holds promise for the development of a duckweed-based expression system to produce an edible vaccine against avian influenza.

  5. Expression of Two N1 Clones with Single Amino Acid Dissimilarity of Avian Influenza H5N1 Virus

    Directory of Open Access Journals (Sweden)

    RISZA HARTAWAN

    2012-12-01

    Full Text Available Two clones of N1 gene derived from isolate A/Dk/Tangerang/Bbalitvet-ACIAR-TE11/2007 (H5N1 exhibit single mismatch of amino acid sequence at position 242 that is threonine and methionine for the clone #3 and #5, respectively. In order to evaluate the effect of the amino acid substitution, these clones were inserted into two different expression vectors that are pEGFP-C1 and pcDNA-3.3 TOPO® TA cloning. Subsequently, the respective recombinant clones were transfected into eukaryotic cells, including CEF, RK13 and VERO using Lipofectamine ‘plus’ reagent. As a result, the clone #3 retaining atypical sequence showed lower expression level rather than the clone #15 in both vectors and all type of cells. The 3D conformational modelling revealed that the mutation occurs in the inner part of glycoprotein embedded within envelope or matrix. Therefore, the missense mutation seems has no effect on the antigenic properties of neuraminidase but this substitution by any means causes lethal mutagenesis in the individual gene expression by reducing level of protein transcript.

  6. Analysis on the Immune Effect of Recombinant Avian Influenza H5N1 Inactivated Vaccine on Broiler Chicken%重组禽流感H5N1灭活疫苗对肉鸡的免疫效果分析

    Institute of Scientific and Technical Information of China (English)

    李再友; 程顺财; 范吉平

    2015-01-01

    To investigate the immune effect of recombinant avian influenza H5N1 inactivated vaccine on broiler chicken, 300 broilers were selected and divided into A group, B group and C group,100 broilers in each group. A group was inoculated with recombinant avian H5N1 inactivated vaccine (H5N1,Re-1),B group was inoculated with avian influenza and newcastle disease recom-binant two live vaccine (rL-H5 strain),C group was control group. The immune effect of inactivat-ed avian influenza vaccine was more obvious than that of recombinant two live vaccine.%为探讨重组禽流感H5N1灭活疫苗对肉鸡的免疫效果,本试验选取300只肉鸡,将其分为A组、B组、C组,每组各100只,其中A组用重组禽流感H5N1灭活疫苗(H5N1,Re-1株)免疫,B组选择禽流感-新城疫重组二联活疫苗(rL-H5株)免疫,C组为空白对照。结果表明,相对于禽流感-新城疫重组二联活疫苗,重组禽流感H5N1灭活疫苗的免疫效果更明显。

  7. The amino-terminal region of the neuraminidase protein from avian H5N1 influenza virus is important for its biosynthetic transport to the host cell surface.

    Science.gov (United States)

    Qian, Guomin; Wang, Song; Chi, Xiaojuan; Li, Hua; Wei, Haitao; Zhu, Xiaomei; Chen, Yuhai; Chen, Ji-Long

    2014-12-01

    Influenza virus neuraminidase (NA) is a major viral envelope glycoprotein, which plays a critical role in viral infection. Although NA functional domains have been determined previously, the precise role of the amino acids located at the N-terminus of avian H5N1 NA for protein expression and intracellular transport to the host plasma membrane is not fully understood. In the present study, a series of N-terminal truncation or deletion mutants of H5N1 NA were generated and their expression and intracellular trafficking were investigated. Protein expression from mutants NAΔ20, NAΔ35, NAΔ40, NAΔ7-20 and NAΔ7-35 was undetectable by immunoblotting and by performing NA activity assays. Mutants NAΔ6, NAΔ11 and NAΔ15-20 showed a marked decreased in protein expression, whereas mutants NAΔ7-15 and NAΔ15 displayed a slight increase in protein expression, compared with that of the native NA protein. These data suggest that amino acid residues 16-20 are vital for NA protein expression, while amino acids 7-15 might suppress NA protein expression. In deletion mutants NAΔ7-15 and NAΔ15 there was an accumulation of NA protein at the juxta-nuclear region, with reduced expression of NA at the cell surface. Although active Cdc42 could promote transport of wild-type NA to the host cell surface, this member of the Rho family of GTPases failed to regulate transport of mutants NAΔ7-15 and NAΔ15. The results of the study reveal that amino acid residues 7-15 of H5N1 NA are critical for its biosynthetic transport to the host cell surface.

  8. The evolutionary dynamics of highly pathogenic avian influenza H5N1 in south-central Vietnam reveals multiple clades evolving from Chinese and Cambodian viruses.

    Science.gov (United States)

    Nguyen, Tinh Huu; Than, Van Thai; Thanh, Hien Dang; Nguyen, Van Quang; Nguyen, Kim Hue; Nguyen, Duc Tan; Park, Jong-Hwa; Chung, In Sik; Jeong, Dae Gwin; Chang, Kyu-Tae; Oh, Tae Kwang; Kim, Wonyong

    2015-10-01

    In Vietnam, highly pathogenic avian influenza (HPAI), such as that caused by H5N1 viruses, is the most highly contagious infectious disease that has been affecting domestic poultry in recent years. Vietnam might be an evolutionary hotspot and a potential source of globally pandemic strains. However, few studies have reported viruses circulating in the south-central region of Vietnam. In the present study, 47 H5N1-positive samples were collected from both vaccinated and unvaccinated poultry farms in the South Central Coast region of Vietnam during 2013-2014, and their genetic diversity was analyzed. A common sequence motif for HPAI virus was identified at HA-cleavage sites in all samples: either RERRRKR/G (clades 2.3.2.1c and 2.3.2.1a) or REGRRKKR/G (clade 1.1.2). Phylogenetic analysis of HA genes identified three clades of HPAI H5N1: 1.1.2 (n=1), 2.3.2.1a (n=1), and 2.3.2.1c (n=45). The phylogenetic analysis indicated that these Vietnamese clades may have evolved from Chinese and Cambodian virus clades isolated in 2012-2013 but are less closely related to the clades detected from the Tyva Republic, Bulgaria, Mongolia, Japan, and Korea in 2009-2011. Detection of the coexistence of virus clades 2.3.2.1 and the very virulent 1.1.2 in the south-central regions suggests their local importance and highlights concerns regarding their spread, both northwards and southwards, as well as the potential for reassortment. The obtained data highlight the importance of regular identification of viral evolution and the development and use of region-specific vaccines.

  9. 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.

  10. 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.

  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.

    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

  12. Role of vaccination-induced immunity and antigenic distance in the transmission dynamics of highly pathogenic avian influenza H5N1.

    Science.gov (United States)

    Sitaras, Ioannis; Rousou, Xanthoula; Kalthoff, Donata; Beer, Martin; Peeters, Ben; de Jong, Mart C M

    2016-01-01

    Highly pathogenic avian influenza (HPAI) H5N1 epidemics in poultry cause huge economic losses as well as sporadic human morbidity and mortality. Vaccination in poultry has often been reported as being ineffective in preventing transmission and as a potential driving force in the selection of immune escape mutants. We conducted transmission experiments to evaluate the transmission dynamics of HPAI H5N1 strains in chickens vaccinated with high and low doses of immune escape mutants we have previously selected, and analysed the data using mathematical models. Remarkably, we demonstrate that the effect of antigenic distances between the vaccine and challenge strains used in this study is too small to influence the transmission dynamics of the strains used. This is because the effect of a sufficient vaccine dose on antibody levels against the challenge viruses is large enough to compensate for any decrease in antibody titres due to antigenic differences between vaccine and challenge strains. Our results show that at least under experimental conditions, vaccination will remain effective even after antigenic changes as may be caused by the initial selection in vaccinated birds.

  13. Cloning of M and NP Gene of H5N1 Avian Influenza Virus and Immune Efficacy of their DNA Vaccines

    Institute of Scientific and Technical Information of China (English)

    Hong-bo FAN; Jun-wei LI; Zhi-lin LI; Wei ZHENG; Po Tien; De-yin GUO

    2007-01-01

    The M and NP genes of H5N1 avian influenza virus (A/chicken/Hubei/489/2004) were amplified by RT-PCR from viral RNA,and cloned into pMD 18-T vector respectively.The expression plasmid containing the M gene (pHM6-m) or the NP gene (pHM6-np) was then constructed by inserting the M or NP gene into the pHM6 eukaryote expression vector; the constructed plasmid was then sequenced.32 BALB/c mice (6-week-old) were divided into four groups at random.Three groups of BALB/c mice were inoculated one time the intramuscular route with either 30 μg of plasmid pHM6-m,30 μg of plasmid pHM6-np or the mixture of plasmid pHM6-m (15 μg ) and pHM6-np(15 μg) respectively.A additional group of mice were injected with 100 μ1 PBS as controls.Two weeks later,all mice were challenged with homologous H5N1 avian influenza virus,and observed in the following 12 days.The survival rates of mice in the pHM6-m group,the pHM6-np group and mixed plasmids group were 62.5% ,25.0% and 50.0%,respectively.Results showed that effective protection could be provided by either pHM6-m or pHM6-np,but pHM6-m provided a better protective effect than pHM6-np.

  14. 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

  15. PDlim2 selectively interacts with the PDZ binding motif of highly pathogenic avian H5N1 influenza A virus NS1.

    Directory of Open Access Journals (Sweden)

    Jia Yu

    Full Text Available The multi-functional NS1 protein of influenza A virus is a viral virulence determining factor. The last four residues at the C-terminus of NS1 constitute a type I PDZ domain binding motif (PBM. Avian influenza viruses currently in circulation carry an NS1 PBM with consensus sequence ESEV, whereas human influenza viruses bear an NS1 PBM with consensus sequence RSKV or RSEV. The PBM sequence of the influenza A virus NS1 is reported to contribute to high viral pathogenicity in animal studies. Here, we report the identification of PDlim2 as a novel binding target of the highly pathogenic avian influenza virus H5N1 strain with an NS1 PBM of ESEV (A/Chicken/Henan/12/2004/H5N1, HN12-NS1 by yeast two-hybrid screening. The interaction was confirmed by in vitro GST pull-down assays, as well as by in vivo mammalian two-hybrid assays and bimolecular fluorescence complementation assays. The binding was also confirmed to be mediated by the interaction of the PDlim2 PDZ domain with the NS1 PBM motif. Interestingly, our assays showed that PDlim2 bound specifically with HN12-NS1, but exhibited no binding to NS1 from a human influenza H1N1 virus bearing an RSEV PBM (A/Puerto Rico/8/34/H1N1, PR8-NS1. A crystal structure of the PDlim2 PDZ domain fused with the C-terminal hexapeptide from HN12-NS1, together with GST pull-down assays on PDlim2 mutants, reveals that residues Arg16 and Lys31 of PDlim2 are critical for the binding between PDlim2 and HN12-NS1. The identification of a selective binding target of HN12-NS1 (ESEV, but not PR8-NS1 (RSEV, enables us to propose a structural mechanism for the interaction between NS1 PBM and PDlim2 or other PDZ-containing proteins.

  16. Epidemiologic and Economic Analyses on Highly Pathogenic Avian Influenza H5N1 in Nigeria and Egypt

    NARCIS (Netherlands)

    Fasina, F.O.

    2015-01-01

    Influenza A viruses have caused several devastating outbreaks in poultry with some zoonotic infections and deaths in humans. To control the viruses and their continuous circulation in poultry population, an understanding of the epidemiology of the viruses is needed. An evaluation of the situation of

  17. Transmission rate and reproductive number of the H5N1 highly pathogenic avian influenza virus during the December 2005-July 2008 epidemic in Nigeria.

    Science.gov (United States)

    Bett, B; Henning, J; Abdu, P; Okike, I; Poole, J; Young, J; Randolph, T F; Perry, B D

    2014-02-01

    We quantified the between-village transmission rate, β (the rate of transmission of H5N1 HPAI virus per effective contact), and the reproductive number, Re (the average number of outbreaks caused by one infectious village during its entire infectious period), of H5N1 highly pathogenic avian influenza (HPAI) virus in Nigeria using outbreak data collected between December 2005 and July 2008. We classified the outbreaks into two phases to assess the effectiveness of the control measures implemented. Phase 1 (December 2005-October 2006) represents the period when the Federal Government of Nigeria managed the HPAI surveillance and response measures, while Phase 2 (November 2006-July 2008) represents the time during which the Nigeria Avian Influenza Control and Human Pandemic Preparedness project (NAICP), funded by a World Bank credit of US$ 50 million, had taken over the management of most of the interventions. We used a total of 204 outbreaks from 176 villages that occurred in 78 local government areas of 25 states. The compartmental susceptible-infectious model was used as the analytical tool. Means and 95% percentile confidence intervals were obtained using bootstrapping techniques. The overall mean β (assuming a duration of infectiousness, T, of 12 days) was 0.07/day (95% percentile confidence interval: 0.06-0.09). The first and second phases of the epidemic had comparable β estimates of 0.06/day (0.04-0.09) and 0.08/day (0.06-0.10), respectively. The Re of the virus associated with these β and T estimates was 0.9 (0.7-1.1); the first and second phases of the epidemic had Re of 0.84 (0.5-1.2) and 0.9 (0.6-1.2), respectively. We conclude that the intervention measures implemented in the second phase of the epidemic had comparable effects to those implemented during the first phase and that the Re of the epidemic was low, indicating that the Nigeria H5N1 HPAI epidemic was unstable.

  18. 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

  19. Highly pathogenic avian influenza virus H5N1 infection in a long-distance migrant shorebird under migratory and non-migratory states.

    Directory of Open Access Journals (Sweden)

    Leslie A Reperant

    Full Text Available Corticosterone regulates physiological changes preparing wild birds for migration. It also modulates the immune system and may lead to increased susceptibility to infection, with implications for the spread of pathogens, including highly pathogenic avian influenza virus (HPAIV H5N1. The red knot (Calidris canutus islandica displays migratory changes in captivity and was used as a model to assess the effect of high plasma concentration of corticosterone on HPAIV H5N1 infection. We inoculated knots during pre-migration (N = 6, fueling (N = 5, migration (N = 9 and post-migration periods (N = 6. Knots from all groups shed similar viral titers for up to 5 days post-inoculation (dpi, peaking at 1 to 3 dpi. Lesions of acute encephalitis, associated with virus replication in neurons, were seen in 1 to 2 knots per group, leading to neurological disease and death at 5 to 11 dpi. Therefore, the risk of HPAIV H5N1 infection in wild birds and of potential transmission between wild birds and poultry may be similar at different times of the year, irrespective of wild birds' migratory status. However, in knots inoculated during the migration period, viral shedding levels positively correlated with pre-inoculation plasma concentration of corticosterone. Of these, knots that did not become productively infected had lower plasma concentration of corticosterone. Conversely, elevated plasma concentration of corticosterone did not result in an increased probability to develop clinical disease. These results suggest that birds with elevated plasma concentration of corticosterone at the time of migration (ready to migrate may be more susceptible to acquisition of infection and shed higher viral titers--before the onset of clinical disease--than birds with low concentration of corticosterone (not ready for take-off. Yet, they may not be more prone to the development of clinical disease. Therefore, assuming no effect of sub-clinical infection on the

  20. Highly pathogenic avian influenza virus H5N1 infection in a long-distance migrant shorebird under migratory and non-migratory states.

    Science.gov (United States)

    Reperant, Leslie A; van de Bildt, Marco W G; van Amerongen, Geert; Buehler, Debbie M; Osterhaus, Albert D M E; Jenni-Eiermann, Susi; Piersma, Theunis; Kuiken, Thijs

    2011-01-01

    Corticosterone regulates physiological changes preparing wild birds for migration. It also modulates the immune system and may lead to increased susceptibility to infection, with implications for the spread of pathogens, including highly pathogenic avian influenza virus (HPAIV) H5N1. The red knot (Calidris canutus islandica) displays migratory changes in captivity and was used as a model to assess the effect of high plasma concentration of corticosterone on HPAIV H5N1 infection. We inoculated knots during pre-migration (N = 6), fueling (N = 5), migration (N = 9) and post-migration periods (N = 6). Knots from all groups shed similar viral titers for up to 5 days post-inoculation (dpi), peaking at 1 to 3 dpi. Lesions of acute encephalitis, associated with virus replication in neurons, were seen in 1 to 2 knots per group, leading to neurological disease and death at 5 to 11 dpi. Therefore, the risk of HPAIV H5N1 infection in wild birds and of potential transmission between wild birds and poultry may be similar at different times of the year, irrespective of wild birds' migratory status. However, in knots inoculated during the migration period, viral shedding levels positively correlated with pre-inoculation plasma concentration of corticosterone. Of these, knots that did not become productively infected had lower plasma concentration of corticosterone. Conversely, elevated plasma concentration of corticosterone did not result in an increased probability to develop clinical disease. These results suggest that birds with elevated plasma concentration of corticosterone at the time of migration (ready to migrate) may be more susceptible to acquisition of infection and shed higher viral titers--before the onset of clinical disease--than birds with low concentration of corticosterone (not ready for take-off). Yet, they may not be more prone to the development of clinical disease. Therefore, assuming no effect of sub-clinical infection on the likelihood of

  1. Vaccine protection of turkeys against H5N1 highly pathogenic avian influenza virus with a recombinant HVT expressing the hemagglutinin gene of avian influenza

    Science.gov (United States)

    Outbreaks of H5 highly pathogenic avian influenza (HPAI) in commercial poultry are a constant threat to animal health and food supplies. While vaccination can enhance protection and reduce the spread of disease, there is considerable evidence that the level of immunity required for protection varies...

  2. 不同职业暴露人群感染H5N1禽流感病毒风险性分析%Risk analysis ot avian influenza virus H5N1 subtype Infection in different occupation groups

    Institute of Scientific and Technical Information of China (English)

    袁洁; 贺锋; 苏良; 叶文

    2011-01-01

    Aim To ssurvey the antibody level of highly pathongenic avian influenza virus H5N1 subtype infection in different kinds of poultry employees in Changsha City. Methods The blood samples of the poultry retailing workers in food markets and polultry breeding workers in large scale enterprises and rural individual farms were collected,H5N1 antibody level were detected by single PIA technique diffusion hemolysis (SRH). Results The H5N1 antibody positive rate of retailers in food markets was 25%, 1% in individual farms and 1.92% in polultry breeding workers in large scale enterprises. The H5N1 antibody positive rate was 10% and 23.88% in male and female employees respectively. Conclusion There is a higher risk of avian influenza virus infection among poultry retailing workers than that of poultry workers in large scale enterprises and rural individual farms. The H5N1 antibody positive rate in female is higher than male employees.%目的 了解长沙地区不同类型禽类职业暴露人群高致病性禽流感H5N1亚型病毒的抗体分布状况,分析不同职业暴露人群H5N1感染的风险性.方法 采集菜市场家禽屠宰零售人员、大型家禽饲养企业工人和农村个体家禽散养人员的血清标本,用单放射免疫扩散溶血技术(SRH)检测 H5N1抗体.结果市场零售人员、农村个体家禽散养人员、企业饲养人员H5N1感染率分别为25%、1%和1.92%,男性从业人员H5N1抗体阳性率为10%,女性为23.88%.结论市场零售人员感染H5N1风险性远高于农村散养人员和企业饲养人员,不同职业人员中女性H5N1抗体阳性率高于男性从业人员.

  3. 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.

  4. 江西省2004~2005年禽流感(H5N1)高危暴露人群感染状况调查%INVESTIGATION ON AVIAN INFLUENZA (H5N1) INFECTION OF HIGH-RISK EXPOSURE GROUPS IN JIANGXI PROVINCE FROM 2004-2005

    Institute of Scientific and Technical Information of China (English)

    程慧健; 袁辉; 宗俊; 王健; 潘欢弘

    2011-01-01

    [Objective] To know avian influenza HSN1 infection of close contacts. [Methods] We found 204 close contacts with animal and human avian influenza from 2004-2005, surveyed their exposure ways, and collected 5ml venous blood from every close contact to test avian influenza H5N1 antibody through horse blood hemagglutination inhibition test and the micro-neutralization test [Results] In close contacts, there were 66.2% fanners, 13.2% students and 1.9% medical staffs. 73% of persons contacted with live poultry of the place that occurred animal avian influenza, 54.4% of persons contacted sick and dead poultry, 12.7% had history of exposure to human avian influenza. During contact process, these close contacts were up to only 16.2% of person taking some protective measures, and the protection was not standardized. Through testing their serum specimens, all these close contacts' H5N1 antibodies were negative. [Conclusion] All close contacts with animal and human avian influenza are not been infected with H5N1 in Jiangxi province from 2004-2005.%[目的]了解江西省H5N1禽流感密切接触者感染状况.[方法]调查2004~2005年禽流感和人禽流感疫情的密切接触者204人的暴露方式,采集静脉血5ml,进行马血球血凝抑制试验和微量中和试验,检测禽流感H5N1抗体水平.[结果]被调查的密切接触者农民占66.2%,学生占13.2%,医护人员占1.9%.73%的人接触过疫点内活禽,54.4%的人接触过病死禽,12.7%的人有禽流感患者接触史,接触过程中,最多只有16.2%的人采取了一些防护措施,且防护不规范.经检测,所有密切接触者血清标本禽流感H5N1抗体阴性.[结论]该省2004~2005年间禽流感和人间禽流感疫情的密切接触者均未感染H5N1.

  5. Serological evidence for non-lethal exposures of Mongolian wild birds to highly pathogenic avian influenza H5N1 virus.

    Directory of Open Access Journals (Sweden)

    Martin Gilbert

    Full Text Available Surveillance for highly pathogenic avian influenza viruses (HPAIV in wild birds is logistically demanding due to the very low rates of virus detection. Serological approaches may be more cost effective as they require smaller sample sizes to identify exposed populations. We hypothesized that antigenic differences between classical Eurasian H5 subtype viruses (which have low pathogenicity in chickens and H5N1 viruses of the Goose/Guangdong/96 H5 lineage (which are HPAIV may be used to differentiate populations where HPAIVs have been circulating, from those where they have not. To test this we performed hemagglutination inhibition assays to compare the reactivity of serum samples from wild birds in Mongolia (where HPAIV has been circulating, n = 1,832 and Europe (where HPAIV has been rare or absent, n = 497 to a panel of reference viruses including classical Eurasian H5 (of low pathogenicity, and five HPAIV H5N1 antigens of the Asian lineage A/Goose/Guangdong/1/96. Antibody titres were detected against at least one of the test antigens for 182 Mongolian serum samples (total seroprevalence of 0.10, n = 1,832, 95% adjusted Wald confidence limits of 0.09-0.11 and 25 of the European sera tested (total seroprevalence of 0.05, n = 497, 95% adjusted Wald confidence limits of 0.03-0.07. A bias in antibody titres to HPAIV antigens was found in the Mongolian sample set (22/182 that was absent in the European sera (0/25. Although the interpretation of serological data from wild birds is complicated by the possibility of exposure to multiple strains, and variability in the timing of exposure, these findings suggest that a proportion of the Mongolian population had survived exposure to HPAIV, and that serological assays may enhance the targeting of traditional HPAIV surveillance toward populations where isolation of HPAIV is more likely.

  6. Chances and limitations of wild bird monitoring for the avian influenza virus H5N1--detection of pathogens highly mobile in time and space.

    Science.gov (United States)

    Wilking, Hendrik; Ziller, Mario; Staubach, Christoph; Globig, Anja; Harder, Timm C; Conraths, Franz J

    2009-08-14

    Highly pathogenic influenza virus (HPAIV) H5N1 proved to be remarkably mobile in migratory bird populations where it has led to extensive outbreaks for which the true number of affected birds usually cannot be determined. For the evaluation of avian influenza monitoring and HPAIV early warning systems, we propose a time-series analysis that includes the estimation of confidence intervals for (i) the prevalence in outbreak situations or (ii) in the apparent absence of disease in time intervals for specified regional units. For the German outbreak regions in 2006 and 2007, the upper 95% confidence limit allowed the detection of prevalences below 1% only for certain time intervals. Although more than 25,000 birds were sampled in Germany per year, the upper 95% confidence limit did not fall below 5% in the outbreak regions for most of the time. The proposed analysis can be used to monitor water bodies and high risk areas, also as part of an early-warning system. Chances for an improved targeting of the monitoring system as part of a risk-based approach are discussed with the perspective of reducing sample sizes.

  7. Analysis of hemagglutinin variance of avian influenza viru (H5N1)%禽流感病毒H5N1亚型血凝素氨基酸序列的变异分析

    Institute of Scientific and Technical Information of China (English)

    王国戗; 牛菊霞; 艾敏

    2009-01-01

    目的 研究不同来源禽流感病毒H5N1亚型血凝素(hemagglutinin,HA)氨基酸序列的变异及变异规律. 方法 以GenBank公开的禽流感病毒H5N1亚型HA氨基酸序列为材料,利用生物信息学的手段分析其同源性及氨基酸变异规律. 结果 46个禽流感病毒H5N1亚型HA氨基酸序列之间的同源性为90%~100%;同一地区来源的氨基酸之间的同源性大于异地来源的同源性;在H5N1亚型HA氨基酸序列中,天冬酰氨酸、丝氨酸、苏氨酸、精氨酸和天门冬氨酸最常发生突变. 结论 禽流感病毒H5N1亚型血凝素氨基酸序列的变异呈现出一定的规律.

  8. The Multibasic Cleavage Site of the Hemagglutinin of Highly Pathogenic A/Vietnam/1203/2004 (H5N1) Avian Influenza Virus Acts as a Virulence Factor in a Host-Specific Manner in Mammals

    OpenAIRE

    2012-01-01

    Highly pathogenic avian influenza (HPAI) viruses of the H5 and H7 subtypes typically possess multiple basic amino acids around the cleavage site (MBS) of their hemagglutinin (HA) protein, a recognized virulence motif in poultry. To determine the importance of the H5 HA MBS as a virulence factor in mammals, recombinant wild-type HPAI A/Vietnam/1203/2004 (H5N1) viruses that possessed (H5N1) or lacked (ΔH5N1) the H5 HA MBS were generated and evaluated for their virulence in BALB/c mice, ferrets,...

  9. The Threat of H5N1 Avian Influenza and Global Preparedness%H5N1禽流感的威胁与全球应对

    Institute of Scientific and Technical Information of China (English)

    田德桥; 郑涛

    2007-01-01

    当前H5N1禽流感在迁徙禽类、家禽中的暴发,以及越来越多的人感染病例的发生,使流感全球大流行的可能性持续存在.简要综述了H5N1禽流感在鸟类和其他动物中的暴发情况,H5N1禽流感的人感染病例,以及全球禽流感应对计划及疫苗、药物、病原体基础研究的进展.

  10. Development and implementation of the quality control panel of RT-PCR and real-time RT-PCR for avian influenza A (H5N1 surveillance network in mainland China

    Directory of Open Access Journals (Sweden)

    Wang Wei

    2011-03-01

    Full Text Available Abstract Background Reverse transcription PCR (RT-PCR and real time RT-PCR (rRT-PCR have been indispensable methods for influenza surveillance, especially for determination of avian influenza. The movement of testing beyond reference lab introduced the need of quality control, including the implementation of an evaluation system for validating personal training and sample proficiency testing. Methods We developed a panel with lysates of seasonal influenza virus (H1N1, H3N2 and B, serials of diluted H5N1 virus lysates, and in-vitro transcribed H5 hemaglutinin (HA and an artificial gene RNAs for RT-PCR and rRT-PCR quality control assessment. The validations of stability and reproducibility were performed on the panel. Additionally, the panel was implemented to assess the detection capability of Chinese human avian influenza networks. Results The panel has relatively high stability and good reproducibility demonstrated by kappa's tests. In the implementation of panel on Chinese human avian influenza networks, the results suggested that there were a relatively low number of discrepancies for both concise and reproducibility in Chinese avian influenza virus net works. Conclusions A quality control panel of RT-PCR and real-time RT-PCR for avian influenza A (H5N1 surveillance network was developed. An availably statistical data, which are used to assess the detection capability of networks on avian influenza virus (H5N1, can be obtained relatively easily through implementation of the panel on networks.

  11. 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

  12. IMMUNOGENICITY OF INACTIVATED H5N1 SUBTYPE AVIAN INFLUENZA VIRUS VACCINES IN DUCKS AND GEESE%重组禽流感病毒灭活疫苗(H5N1亚型)对鸭和鹅的免疫效果观察

    Institute of Scientific and Technical Information of China (English)

    沈欣悦; 程旭; 刘梅; 尤素兰; 刘加圣; 戴亚斌

    2013-01-01

      由H5N1亚型禽流感病毒(Avian influenza virus,AIV)引起的高致病性禽流感(highly pathogenic avian influenza, HPAI)是禽类的一种烈性传染病,疫苗免疫是禽流感防控中的重要环节。本试验采用重组禽流感病毒灭活疫苗(H5N1,Re-5株)和重组禽流感病毒H5亚型二价灭活疫苗(H5N1、Re-5株+Re-4株)进行了鸭和鹅的免疫试验,对免疫鸭和鹅的抗体水平进行了动态监测。试验结果表明,两种疫苗对鸭和鹅均具有良好的免疫效果。基于试验结果提出了鸭和鹅禽流感免疫程序:2 w左右首免,4~5 w时二免,开产前三免,此后每隔4~5个月加强免疫一次。%Highly pathogenic avian influenza (HPAI) is caused by H5N1 subtype of avian influenza virus (AIV), and the vaccination plays a key role in prevention and control. In this study, ducks and geese were immunized with either inactivated avian influenza vaccine (H5N1 subtype, Re-5 strain) or bivalent inactivated avian influenza vaccine (H5N1 subtype, Re-5 strain+Re-4 strain) and hemagglutination inhibition (HI) antibody levels were detected. Both vaccines induced strong immune responses in ducks and geese. Based on these results, the proposal for the AIV vaccination program in ducks and geese should include the initial dose at 2-week-old, the second dose at 4-5-week-old, the third dose before the beginning of laying period, and further boosters at every 4-5 month interval.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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.

  15. Detection of avian influenza virus H5N1 subtype in organs of chicken affected by higly pathogenic avian infuenza in East and West Java by using immunohistochemical technique

    Directory of Open Access Journals (Sweden)

    R Damayanti

    2004-10-01

    Full Text Available The study was conducted to detect antigen H5N1 of highly pathogenic Avian Influenza (HPAI virus in various farms in East and West Java. The immunohistochemical technique was applied due to Hematoxilin-eosin (H&E staining was impossible to visualize the antigen in tissue. Immunohistochemical staining was applied for some visceral organs collected from the areas where the outbreaks occurred in September-October 2003. The specimens were processed as histopathological paraffin blocks using standard method. The blocks that were suspected to have antigen H5N1 were cut and rabbit antisera to H5N1 produced from the local isolate was applied as the primary antibody. Biotinylated secondary antibody and avidin biotin peroxidase from a commercial kit were administered. The antigen present in the tissues were visualized by adding a substrate called Amino Ethyl Carbazole (AEC resulting in reddish brown colour. This immunostaining proved to be accurate and reliably quick method to detect H5N1 antigen present in the avian tissues. In conclusion, the outbreak of bird flu was caused by H5N1 strain and the antigen could be found in wattles, combs, brain, trachea, lungs, heart, proventriculus, liver, spleen, kidney and ovary.

  16. Pathogenicity of Genetically Similar, H5N1 Highly Pathogenic Avian Influenza Virus Strains in Chicken and the Differences in Sensitivity among Different Chicken Breeds.

    Science.gov (United States)

    Matsuu, Aya; Kobayashi, Tomoko; Patchimasiri, Tuangthong; Shiina, Takashi; Suzuki, Shingo; Chaichoune, Kridsada; Ratanakorn, Parntep; Hiromoto, Yasuaki; Abe, Haruka; Parchariyanon, Sujira; Saito, Takehiko

    2016-01-01

    Differences in the pathogenicity of genetically closely related H5N1 highly pathogenic avian influenza viruses (HPAIVs) were evaluated in White Leghorn chickens. These viruses varied in the clinical symptoms they induced, including lethality, virus shedding, and replication in host tissues. A comparison of the host responses in the lung, brain, and spleen suggested that the differences in viral replication efficiency were related to the host cytokine response at the early phase of infection, especially variations in the proinflammatory cytokine IL-6. Based on these findings, we inoculated the virus that showed the mildest pathogenicity among the five tested, A/pigeon/Thailand/VSMU-7-NPT/2004, into four breeds of Thai indigenous chicken, Phadu-Hung-Dang (PHD), Chee, Dang, and Luang-Hung-Khao (LHK), to explore effects of genetic background on host response. Among these breeds, Chee, Dang, and LHK showed significantly longer survival times than White Leghorns. Virus shedding from dead Thai indigenous chickens was significantly lower than that from White Leghorns. Although polymorphisms were observed in the Mx and MHC class I genes, there was no significant association between the polymorphisms in these loci and resistance to HPAIV.

  17. Phylodynamics of H5N1 Highly Pathogenic Avian Influenza in Europe, 2005–2010: Potential for Molecular Surveillance of New Outbreaks

    Directory of Open Access Journals (Sweden)

    Mohammad A. Alkhamis

    2015-06-01

    Full Text Available Previous Bayesian phylogeographic studies of H5N1 highly pathogenic avian influenza viruses (HPAIVs explored the origin and spread of the epidemic from China into Russia, indicating that HPAIV circulated in Russia prior to its detection there in 2005. In this study, we extend this research to explore the evolution and spread of HPAIV within Europe during the 2005–2010 epidemic, using all available sequences of the hemagglutinin (HA and neuraminidase (NA gene regions that were collected in Europe and Russia during the outbreak. We use discrete-trait phylodynamic models within a Bayesian statistical framework to explore the evolution of HPAIV. Our results indicate that the genetic diversity and effective population size of HPAIV peaked between mid-2005 and early 2006, followed by drastic decline in 2007, which coincides with the end of the epidemic in Europe. Our results also suggest that domestic birds were the most likely source of the spread of the virus from Russia into Europe. Additionally, estimates of viral dispersal routes indicate that Russia, Romania, and Germany were key epicenters of these outbreaks. Our study quantifies the dynamics of a major European HPAIV pandemic and substantiates the ability of phylodynamic models to improve molecular surveillance of novel AIVs.

  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. 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.

  20. 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

  1. Investigating a crow die-off in January-February 2011 during the introduction of a new clade of highly pathogenic avian influenza virus H5N1 into Bangladesh.

    Science.gov (United States)

    Khan, Salah Uddin; Berman, Lashondra; Haider, Najmul; Gerloff, Nancy; Rahman, Md Z; Shu, Bo; Rahman, Mustafizur; Dey, Tapan Kumar; Davis, Todd C; Das, Bidhan Chandra; Balish, Amanda; Islam, Ausraful; Teifke, Jens P; Zeidner, Nord; Lindstrom, Steven; Klimov, Alexander; Donis, Ruben O; Luby, Stephen P; Shivaprasad, H L; Mikolon, Andrea B

    2014-03-01

    We investigated unusual crow mortality in Bangladesh during January-February 2011 at two sites. Crows of two species, Corvus splendens and C. macrorhynchos, were found sick and dead during the outbreaks. In selected crow roosts, morbidity was ~1 % and mortality was ~4 % during the investigation. Highly pathogenic avian influenza virus H5N1 clade 2.3.2.1 was isolated from dead crows. All isolates were closely related to A/duck/India/02CA10/2011 (H5N1) with 99.8 % and A/crow/Bangladesh/11rs1984-15/2011 (H5N1) virus with 99 % nucleotide sequence identity in their HA genes. The phylogenetic cluster of Bangladesh viruses suggested a common ancestor with viruses found in poultry from India, Myanmar and Nepal. Histopathological changes and immunohistochemistry staining in brain, pancreas, liver, heart, kidney, bursa of Fabricius, rectum, and cloaca were consistent with influenza virus infection. Through our limited investigation in domesticated birds near the crow roosts, we did not identify any samples that tested positive for influenza virus A/H5N1. However, environmental samples collected from live-bird markets near an outbreak site during the month of the outbreaks tested very weakly positive for influenza virus A/H5N1 in clade 2.3.2.1-specific rRT-PCR. Continuation of surveillance in wild and domestic birds may identify evolution of new avian influenza virus and associated public-health risks.

  2. 2株H5N1亚型禽流感病毒人工感染鸭的11项血液生化指标测定%Eleven Blood Biochemical Indexes Assay of Ducks Experimentally Infected with Two Avian Influenza Viruses(H5N1)

    Institute of Scientific and Technical Information of China (English)

    叶远兰; 周泉鹤; 李玉谷

    2011-01-01

    鸭肌肉接种禽流感病毒A/duck/Guangdong/185/2004(H5N1)和A/duck/Guangdong/221/2004(H5N1)后,血清中的丙氨酸氨基转移酶、天门冬氨酸氨基转移酶、碱性磷酸酶、总蛋白、肌酐、总胆固醇、钙和磷明显升高;葡萄糖和甘油三酯明显降低;白蛋白表现为先下降后升高的变化趋势.作者认为,检测这些血液生化指标对于诊断禽流感具有一定的参考价值.%Ducks intramuscularly inoculated with avian influenza virus strains, A/duck/Guangdong/185/2004 (H5N1) and A/duck/Guangdong/221/2004(H5N1), showed that the serum alanine aminotransferase(glutamic-pyruvic transminase), aspartate aminotransferase(glutamic-oxaloacetic transminase), alkaline phosphatase, total protein, creatinine, cholesterol, calcium and phosphorus were significantly increased; while glucose and triglycerides were obviously decreased; albumin was decreased at first and increased later. We considered that assaying these blood biochemical indexes were useful for diagnosing avian influenza.

  3. 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。

  4. Pathological Change for ICR Mice Infected with Avian Influenza H5N1 Viruses%禽流感H5N1病毒感染ICR小鼠的病理变化

    Institute of Scientific and Technical Information of China (English)

    刘忠华; 李志东; 谭文雅; 黄韧

    2008-01-01

    [目的]通过鼻腔将H5N1禽流感病毒接种ICR小鼠,观察其主要器官组织的病理变化.[方法]麻醉ICR小鼠后将100 μL H5N1禽流感病毒原液用移液枪滴入接毒组小鼠鼻腔,接毒后14 d内每隔24 h取材一次,采用福尔马林固定,石蜡包埋、切片,HE染色.[结果]禽流感H5N1病毒感染ICR小鼠后表现出明显的病理改变.ICR小鼠的肺部病变最严重,表现为间质性肺炎,肺间质充血、水肿和淋巴细胞浸润,血管周围淋巴细胞浸润,毛细血管扩张,上皮细胞变性、坏死、脱落,并有充血和单核细胞浸润,肺泡壁明显增宽,血管充血.有的肺泡溶合,呈气肿状.肝、肾、脑等其它脏器也出现病变.[结论]禽流感ICR小鼠模型能复制出人类禽流感疾病的许多病理特征,禽流感H5N1病毒感染ICR小鼠的肺病理类似于人禽流感严重病例的肺病理.

  5. H5N1禽流感病毒感染雏鸭的病理学观察%Pathological observation of ducklings infected with H5N1 avian influenza virus

    Institute of Scientific and Technical Information of China (English)

    田伟; 吕晓萍; 马宏伟; 郑世民; 刘明

    2009-01-01

    通过眼观病变观察和组织病理学检查方法对H5N1禽流感病毒感染雏鸭的各器官组织病理变化进行了系统的研究,为H5N1禽流感病毒致病机制的研究及禽流感的-临床诊断提供理论依据.结果显示,雏鸭感染H5N1禽流感病毒后,除机体出现临床症状外,主要呈现明显的神经症状;病理剖检发现胰腺、肝、脾肿大,并见大小不一、数量不等的坏死灶;组织病理学检查发现全身各器官组织呈现出血、坏死和淋巴细胞浸润.经分析,多器官发生明显的细胞变性、坏死很可能是H5NI亚型禽流感病毒致病性的重要表现形式之一.

  6. H5N1禽流感病毒抗原基因的体外转录及RNA标准品构建%In vitro transcription of HA, NA and M gene of H5N1 avian influenza virus and preparation of RNA standards

    Institute of Scientific and Technical Information of China (English)

    张锦海; 王忠灿; 郑纪山; 吕恒; 鲁娟东; 顾海涛; 王平; 王长军

    2011-01-01

    目的 通过基因克隆和体外转录,获得H5N1禽流感病毒血凝素(HA)、神经氨酸酶(NA)、基质蛋白M(M)基因的RNA片段,为病原学检测提供阳性定量标准品.方法 设计H5N1禽流感病毒的HA、NA及M基因全长开放阅读框的克隆引物,提取H5N1禽流感病毒总RNA,用RT-PCR获得相应片段,分别连接至Pgem-T easy质粒,转化宿主菌XL10-Gold,然后提取阳性克隆的重组质粒DNA,测序鉴定后用限制性核酸内切酶Nde I酶切线性化,用T7 RNA聚合酶进行体外转录,产物用Dnase酶处理、纯化后测定浓度,用实时荧光定量PCR构建标准曲线进行验证.结果 获得含H5N1禽流感病毒HA、NA、M基因全长开放阅读框序列的准确定量拷贝数的RNA片段,质量浓度分别为503.9、379.2、437.8ng/μl.结论 获得的RNA片段可作为H5N1禽流感病毒核酸快速检测方法的阳性定量标准品.%Objective To obtain hemagglutinin (HA), neuraminidase (NA) and matrix (M) gene segments of H5N1 avian influenza virus with gene cloning and in vitro transcription and to provide positive quantitative standard for pathogen detection.Methods According to the specific sequence of HA/NA/M gene of H5N1 avian influenza vires, the primers were designed and synthesized. Total RNA was extracted from H5N1 avian influenza virus and reverse transcribed to cDNA using RT-PCR. The HA/NA/M cDNAs were ligated with pGEM-T easy vector and transformed to bacterium XL10-Gold. Recombinant plasmid DNA extracted from positive clones was sequenced and digested with endonucleases Nde Ⅰ. The linearized plasmids were used to transcript RNA in vitro by T7 RNA polymerases, then the products were purificated and fragmented with DNase for the detection of the concentration of cRNAs. Standard curves were constructed using Real-time fluorescence quantitative RT-PCR. Results The full-length cRNAs of HA/NA/M genes of H5N1 avian influenza virus were obtained by in vitro transcription with precise

  7. Research on Multiplication of H5N1 Subtype Avian Influenza Virus in MDCK Cell Culture System%H5N1亚型禽流感病毒在MDCK细胞中增殖条件的研究

    Institute of Scientific and Technical Information of China (English)

    孙德君; 梁婉楠; 丁国杰; 刘鑫莹; 袁明霞; 闫妍

    2014-01-01

    目的:探索H5N1亚型禽流感病毒在MDCK中增殖规律,确定最佳增殖条件。方法将H5N1亚型禽流感病毒接种到6孔板培养的MDCK细胞进行增殖试验,检测不同病毒感染量、不同浓度TPCK-胰酶,接毒后不同时间病毒的HA滴度。根据确定的最佳增殖条件将病毒接种到微载体培养的MDCK细胞中进行大规模增殖。结果:最佳病毒增殖条件接毒量MOI为5×10-4、TPCK-胰酶浓度为4μg/mL,在5 L生物反应器中重复验证,获得稳定的试验结果,病毒血凝价最高为8 log2。结论:本研究为禽流感疫苗的生物反应器规模化生产奠定了基础。%To explore the regularity for the multiplication of avian influenza virus subtype H5N1 in MDCK cell culture system and determine the optimal proliferation conditions. H5N1 subtype of avian influenza virus was in-oculated into the MDCK cell growing on 6 well plate, and the HA titers of virus at different time were detected in the conditions of different infectious doses, and different concentrations of TPCK-trypsin. The optimal conditions were determined. Then the H5N1 subtype avian influenza virus was grown in microcarrier-based MDCK cell. It was demonstrated that high virus yield with a hemagglutination unit of 8 log2 (1:256) could be obtained under the optimal conditions of multiplication. The result indicated the H5N1 subtype avian influenza virus could be pro-duced in microcarrier-based MDCK cell in a large-scale culture system with a high virus yield and demonstrates the feasibility of the development of mammalian cell-based in influenza vaccine in microcarrier culture systems.

  8. 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

  9. Prioritizing live bird markets at risk of avian influenza H5N1 virus contamination for intervention: a simple tool for low resource settings.

    Science.gov (United States)

    Samaan, Gina; Indriani, Risa; Carrasco, Luis Roman; Lokuge, Kamalini; Cook, Alex R; Kelly, Paul M; Adjid, Rma

    2012-12-01

    Live bird markets (LBMs) are at risk of contamination with the avian influenza H5N1 virus. There are a number of methods for prioritizing LBMs for intervention to curb the risk of contamination. Selecting a method depends on diagnostic objective and disease prevalence. In a low resource setting, options for prioritization are constricted by the cost of and resources available for tool development and administration, as well as the resources available for intervention. In this setting, tools can be developed using previously collected data on risk factors for contamination, and translated into prediction equations, including decision trees (DTs). DTs are a graphical type of classifier that combine simple questions about the data in an intuitive way. DTs can be used to develop tools tailored to different diagnostic objectives. To demonstrate the utility of this method, risk factor data arising from a previous cross-sectional study in 83 LBMs in Indonesia were used to construct DTs. A DT with high specificity was selected for the initial stage of an LBM intervention campaign in which authorities aim to focus intervention resources on a small set of LBMs that are at near-certain risk of contamination. Another DT with high sensitivity was selected for later stages in an intervention campaign in which authorities aim to detect and prioritize all LBMs with the risk factors for virus contamination. The best specific DT achieved specificity of 77% and the best sensitive DT achieved sensitivity of 90%. The specific DT had two variables: the size of the duck population in the LBM and the human population density in the LBM's district. The sensitive DT had three variables: LBM location, whether solid waste was removed from the LBM daily and whether the LBM was zoned to separate the bird holding, slaughtering and sale areas. High specificity or sensitivity will be preferred by authorities depending on the stage of the intervention campaign. The study demonstrates that simple

  10. Reduced experimental infectivity and transmissibility of intercontinental H5 (H5N8 and H5N2) compared to Eurasian H5N1 highly pathogenic avian influenza viruses for chickens, turkeys, and Japanese quail

    Science.gov (United States)

    H5N1 high pathogenicity avian influenza (HPAI) virus (HPAIV) emerged in 1996 in Guangdong China and has since spread to infect and cause deaths in wild birds, poultry and humans in over 63 countries in Asia, Europe and Africa; and more recently a reassortant H5N8 clade 2.3.4.4 HPAI virus has spread ...

  11. 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...

  12. On Diagnose of Avian Influenza H5N1 and Its Study of Clinical Pathology%H5N1亚型禽流感的诊断及临床病理学研究

    Institute of Scientific and Technical Information of China (English)

    马国文; 李桂枝; 刘锴; 杨明霞

    2003-01-01

    对一起鸡传染病进行了病原鉴定并对其自然死亡的46例蛋鸡进行了临床病理学研究,结果表明,本起鸡病为A型禽流感,H5N1亚型,属高致死性(HPAI);急性热性出血性败血症;急性坏死性胰腺炎;非化脓性脑炎;卡他性上呼吸道炎;卡他性、间质性肺炎.

  13. 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.

  14. 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.

  15. H5N1禽流感病毒羊驼重链单域抗体的制备和功能鉴定%Preparation and characterization of recombinant VHH antibody against H5N1 hemagglutinin from avian influenza virus

    Institute of Scientific and Technical Information of China (English)

    夏立亮; 吴标; 程亚庭; 包文静; 赵国屏; 王颖

    2012-01-01

    目的:获得具有中和活性、高特异性和稳定性的抗H5N1禽流感病毒血凝素蛋白(HA)的羊驼重链单域(VHH)抗体.方法:利用pET-22b表达载体诱导表达抗H5N1禽流感病毒HA VHH抗体蛋白,以包涵体形式表达的VHH抗体蛋白采用最优复性方法进行复性后,获得高纯度的VHH抗体,分别采用ELISA法鉴定VHH抗体的亲和力和热稳定性,采用血凝抑制实验鉴定抗体的特异性和体外中和活性.结果:经复性的抗H5N1禽流感HA VHH抗体对H5N1禽流感病毒HA具有良好的特异性.通过对三种不同复性方法比较,利用柱上复性的VHH23抗体具有较好的热稳定性,亲和力为9.1×10-7 mol/L,同时对H5N1禽流感病毒HA具有良好的体外中和活性.结论:实验结果表明通过原核表达获得具有较好中和活性、特异性及稳定性的抗H5N1禽流感病毒VHH抗体,为进一步开展抗体的体内病毒中和试验奠定良好基础.%Objective; To prepare and characterize camelid VHH antibody against hemagglutinin from H5N1 avian influenza virus. Methods: Recombinant expression vector pET-22b-VHH23 was constructed and VHH antibody against hemagglutinin from H5N1 a-vian influenza virus was expressed in E. Coli BL2l( DE3 ) strain by IPTG induction. As VHH antibody protein was expressed in inclusion body,there different refolding methods were compared for the refolding of VHH antibody in which the optimal methods were adopted for preparation of VHH antibody. The activity and thermal stability of VHH antibodies were tested by ELISA while hemagglutination-inhibition assay was perfomed to determine the specificity and neutralizing activity. Results; By using on-column refolding procedure, VHH antibody has been obtained with highest yield and good quality. This antibody specifically recognized hemagglutinin derived from H5N1 avian influenza virus as well as in vitro inhibition against hemagglutinin-mediated red blood cell agglutination. The affinity constant of VHH

  16. 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.

  17. 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.

  18. H5N1型禽流感病毒广谱中和单克隆抗体的筛选及其中和机制初步研究%Broad-spectrum Neutralizing Monoclonal Antibodies Against H5N1 Avian Influenza A Viruses and Primary Research on The Mechanism

    Institute of Scientific and Technical Information of China (English)

    张晓; 曾晓燕; 刘哲; 金秋; 徐言; 冯振卿; 焦永军

    2011-01-01

    Avian influenza is a highly contagious disease of birds caused by A influenza viruses. The circulation in humans by the highly pathogenic H5N1 avian flu in the past few years have caused most pandemics and have heightened fear that the next influenza pandemic is due. Antibodies could be used as an efficient anti-virus agent in clinical therapy. The full-length HA of the A/Jiangsu/1/2007(H5N 1) about 1.7 kb was amplified, subcloned to the pFastBac vector and recombinant bacmid DNA was selected. The recombinant HA was expressed and purified HA about 70 ku was used as the antigen to immunize Balb/c mice. The whole H5N1 virus was used to select 5 mono-antibodies (mAbs), and all of them were tested using microneutralization assays. 8G10D7, one of the antibodies, had broad neutralizing effect against clade 2 and clade 9 H5N1 avian influenza A viruses, and the IC50 was from 1 : 256 to I ' 64. When detected with 8G10D7, all 4 viruses showed 70 ku and 43 ku protein band,which confirms that the binding site of the scFv antibodies were located at the HA1 domain. The nucleuses of MDCK cells infected by 4 viruses were colored purple, and red around the nucleus. 8Gl 0D7 showed HI activity to the 4 viruses, the HI has a positive correlation with neutralization concentration IC50, which also further confirms that the binding site of the scFv antibodies were located at the HA1 domain. When the mAb 8Gl 0D7 was used for the study of prophylaxis and therapeutic effect on influenza A viruses infection in an embryonated chicken eggs model. It had a complete 100% protection effect on the H5N1 viruses in avian host in the prophylactic and therapeutic groups. The 100% preventive protection effect could be reached when challenged with H5N1 avian influenza A viruse in human host in the prophylactic groups, and there is also a 87.5% protection effect with H5N1 viruses in human host in the therapeutic groups. Thereby, the study suggests that the mAb 8G10D7 could be used in therapies to

  19. 一株H5N1亚型禽流感病毒全基因组克隆及HA基因分子进化分析%Cloning and sequencing full-length genome of H5N1 avian influenza A virus and molecular evolution analysis of HA gene

    Institute of Scientific and Technical Information of China (English)

    徐军强; 吴叔文; 詹发先; 喻明霞; 江永忠; 霍细香

    2011-01-01

    Objective To clone and sequence full-length genome of the avian influenza A/Chicken/Hubei/489/ 2004(H5N1 ) virus,in order to analyze genetic mutation patterns of HA gene and polygenetic relationship between A/ Chicken/Hubei/489/2OO4(H5Nl) virus and other strains since 1996. Methods 8 genes of the avian influenza A/ Chicken/Hubei/489/2004 ( H5N1 ) virus were amplified and cloned, and then genetic mutation analysis and phylogenetic trees were made by bioinformatics software. Results Full-length genome of the avian influenza A/ Chicken/Hubei/489/2004(H5N1)virus were cloned into the vector of PMD18-T. Genetic evolution analysis showed that there is a specific cleavage site of "PQRERRRKKR" , which was proved be related with virulence. In addition, molecular phylogenetic trees of HA gene revealed that A/Chicken/Hubei/ 489/2004 virus were closely related to HSN1 viruses of 2000-2006 isolated in Hong Kong and in Southeast Asia. Conclusion the influenza A/Chicken/ Hubei/489/2004 ( H5N1) virus was closest genetic relatives to the influenza A/Chicken/HongKong/YU777/2002 (H5N1) virus, and it was most possible that the avian influenza outbreak was caused by the 2002 lineage of Hong Kong.%目的 对禽流感H5N1亚型病毒株A/Chicken/Hubei/489/2004的全基因组进行克隆和测序,并分析血凝素基因HA的遗传突变特点及其与1996年以来其他病毒株的亲缘关系.方法 通过RT-PCR扩增病毒株A/C hicken/Hubei/489/2004的8个基因,并将其克隆到测序载体;在对病毒株全基因组序列测定基础上,利用生物信息学软件对HA基因进行遗传进化分析.结果 病毒株A/Chicken/Hubei/489/2004的全基因组克隆到PMD18-T;遗传进化分析显示该毒株HA蛋白具有与致病性有关的切割位点“PQRERRRKKR”,并且与2000~2006年在香港从人和禽体内分离的H5N1亲缘关系相近,也与2003~2004年在东南亚从人和禽体内分离的H5N1极其相关.结论 A/Chicken/H ubei/489/2004病

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. 2010年绵阳市H5N1禽流感职业暴露人群流行病学和血清学调查分析%Serology and epidemiological investigation on H5N1 subtype avian influenza virus among occupational exposed population of Mianyang in 2010

    Institute of Scientific and Technical Information of China (English)

    史映红; 刘昌弟

    2012-01-01

    Objective To understand the H5N1 subtype avian influenza virus infection status of occupational exposed population and provide background data and scientific evidences for prevention and control. Method Total of 200 occupational exposed people were given questionnaire to survey the work environment and personal , and so on. The antibody of H5N1 subtype avian influenza virus was detected simultaneously. Results Half of the occupational exposed people worked in drafty and clean environment About 37% didn' t know how to deal with the birds dirty and 59% didn' t know protect environment Only 20% to 32% people worn protective facilities when contacted birds every time. 31.65% people had damages in hands or foots in recent half year. All the antibody of H5N1 subtype avian influenza virus was negative. Conclusions The H5N1 subtype avian influenza virus did not existed in our city now, but we still need to monitoring the epidemic situation of birds and humans, enhance the health education to occupational exposures and teach them protected themselves and reduce the infection.%目的 了解绵阳市职业人群H5N1禽流感病毒感染状况,为人禽流感防治提供基础资料和科学依据.方法 对全市9个县市区的200人职业人群发放问卷,对工作环境、个人防护措施等进行调查,同时采集其血清查H5N1禽流感病毒抗体.结果 我市职业人群在通风好、干净整洁的环境中工作的占50%以上;37%的职业人群不懂得如何处理禽类污物.清理污物后59%的人不懂得保护环境.个人防护方面,能做到每次接触禽类均穿戴防护设施的人群占20%~32%.而近半年来职业人群手足部位皮肤曾明显破损者占31.65%.200人血清中未查见H5N1禽流感病毒抗体.结论 我市禽类中暂时不存在H5N1禽流感病毒,相关部门应做好禽流感病毒禽间和人间监测,加强对职业暴露人群的健康教育,使其做好自身防护,减少感染机会.

  3. 几种野生水禽H5N1禽流感疫苗免疫效果比较%Comparison on the immune effect of several vaccines against subtype H5N1 of Avian Influenza in wild waterfowl

    Institute of Scientific and Technical Information of China (English)

    李莹; 吴秀山; 张成林; 郑常明; 黄淑芳

    2012-01-01

    This survey selected 4 species of waterfowl raised in Beijing Zoo and a group of little swan raised in Hangzhou Zoo as the object of antibody test for vaccination of subtype H5N1 of Avian Influenza.The results showed that the antibody titer achieved the peak 20 days after vaccination,then gradually decreased.The rate of antibody decline was different between species.%选择北京动物园饲养的4种雁行目水禽和杭州动物园小天鹅进行H5N1禽流感疫苗免疫,考察其免疫效果。结果表明,在免疫约20 d抗体滴度达到峰值,后逐渐下降,抗体水平下降速度因野生水禽的种类不同而不同。

  4. The Multibasic Cleavage Site of the Hemagglutinin of Highly Pathogenic A/Vietnam/1203/2004 (H5N1) Avian Influenza Virus Acts as a Virulence Factor in a Host-Specific Manner in Mammals

    Science.gov (United States)

    Suguitan, Amorsolo L.; Matsuoka, Yumiko; Lau, Yuk-Fai; Santos, Celia P.; Vogel, Leatrice; Cheng, Lily I.; Orandle, Marlene

    2012-01-01

    Highly pathogenic avian influenza (HPAI) viruses of the H5 and H7 subtypes typically possess multiple basic amino acids around the cleavage site (MBS) of their hemagglutinin (HA) protein, a recognized virulence motif in poultry. To determine the importance of the H5 HA MBS as a virulence factor in mammals, recombinant wild-type HPAI A/Vietnam/1203/2004 (H5N1) viruses that possessed (H5N1) or lacked (ΔH5N1) the H5 HA MBS were generated and evaluated for their virulence in BALB/c mice, ferrets, and African green monkeys (AGMs) (Chlorocebus aethiops). The presence of the H5 HA MBS was associated with lethality, significantly higher virus titers in the respiratory tract, virus dissemination to extrapulmonary organs, lymphopenia, significantly elevated levels of proinflammatory cytokines and chemokines, and inflammation in the lungs of mice and ferrets. In AGMs, neither H5N1 nor ΔH5N1 virus was lethal and neither caused clinical symptoms. The H5 HA MBS was associated with mild enhancement of replication and delayed virus clearance. Thus, the contribution of H5 HA MBS to the virulence of the HPAI H5N1 virus varies among mammalian hosts and is most significant in mice and ferrets and less remarkable in nonhuman primates. PMID:22205751

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Progress on H5N1 Avian Influenza Virus and New Antiviral Drugs%H5Nl禽流感病毒及抗病毒新药的研究进展

    Institute of Scientific and Technical Information of China (English)

    边玲; 陈执中

    2008-01-01

    禽流感病毒(avian influenza virus,AIV)是引起鸟禽类烈性传染病的病毒.1997年发现AIV跨越物种障碍使人感染.H5N1是有强致病力的禽流感病毒,感染H5N1的患者死亡率高.本文综述了禽流感病毒致病机制研究以及抗H5N1禽流感病毒新药的进展,包括:神经氨酸苷酶新抑制剂及核酸基的抗禽流感病毒新药--免疫调节双链核糖核酸聚ICLC脂质体和反义寡核苷酸.

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  10. Analysis of Avian Influenza Virus Epitopes and the Design of H5N1 Virus Genetic Engineering Vaccine%禽流感病毒抗原表位分析及H5N1亚型基因工程疫苗设计

    Institute of Scientific and Technical Information of China (English)

    刘学东; 王志亮; 包振民

    2012-01-01

    In this study, we choose the asian H5N1 subtype avian influenza virus, use software to analyze the gene sequences of the HA1 (Hemagglutnin, HA, hemagglutinin) and NP (Nucleocapsid protein, capsid protein), and optimize major T cell epitopes and B cell epitopes of the HA1 protein and the major CTL (Cytotoxicity T lymphocyte cytotoxic T lymphocyte) epitope of the NP protein. According to these preferred epitopes, we designed the avian influenza virus subtype H5N1 recombinant vaccine. Genetically engineered vaccine expression vector pRSET-AIV was constructed, exogenous gene can be well expressed in E, coli system. Mice immunized with expression products, serum IgA and IgG antibody levels were significantly increased, IL-2, IL-4 and IFN-y cytokines were tested in vitro spleen cells. The antigen of genetic engineering was verified. It's confirmed that the vaccine stimulates the cellulat's immunity while it activates the humoral immunity.%以亚洲地区H5N1亚型禽流感病毒(Avian Influenze Virus)流行株为研究对象,利用计算机软件,对同源性较高的HA1(Hemagglutnin,HA,血凝素)和NP(Nucleocapsid protein,核衣壳蛋白)进行全基因序列分析,优选出HA1蛋白的主要T细胞表位和B细胞表位,以及NP蛋白的主要CTL(Cytotoxicity T lymphocyte,细胞毒性T淋巴细胞)表位.依据这些优选表位,设计了禽流感病毒H5N1亚型基因工程疫苗.构建了基因工程疫苗表达载体pRSET-AIV,外源基因能够在大肠杆菌表达系统中得到良好表达.表达产物免疫小鼠后,血清中IgA和IgG抗体水平明显上升,在体外培养脾细胞可产生IL-2、IL-4和IFN-γ细胞因子.验证了该H5N1亚型基因工程疫苗的抗原性,证实该基因工程疫苗在免疫小鼠体内激发体液免疫的同时调动了细胞免疫.

  11. Outbreaks of highly pathogenic avian influenza H5N1 clade 2.3.2.1c in hunting falcons and kept wild birds in Dubai implicate intercontinental virus spread.

    Science.gov (United States)

    Naguib, Mahmoud M; Kinne, Jörg; Chen, Honglin; Chan, Kwok-Hung; Joseph, Sunitha; Wong, Po-Chun; Woo, Patrick C Y; Wernery, Renate; Beer, Martin; Wernery, Ulrich; Harder, Timm C

    2015-11-01

    Highly pathogenic avian influenza viruses (HPAIVs) of subtype H5N1 have continued to perpetuate with divergent genetic variants in poultry within Asia since 2003. Further dissemination of Asian-derived H5 HPAIVs to Europe, Africa and, most recently, to the North American continent has occurred. We report an outbreak of HPAIV H5N1 among falcons kept for hunting and other wild bird species bred as falcon prey in Dubai, United Arab Emirates, during the autumn of 2014. The causative agent was identified as avian influenza virus subtype H5N1, clade 2.3.2.1c, by genetic and phylogenetic analyses. High mortality in infected birds was in accordance with systemic pathomorphological and histological alterations in affected falcons. Genetic analysis showed the HPAIV H5N1 of clade 2.3.2.1c is a reassortant in which the PB2 segment was derived from an Asian-origin H9N2 virus lineage. The Dubai H5N1 viruses were closely related to contemporary H5N1 HPAIVs from Nigeria, Burkina-Faso, Romania and Bulgaria. Median-joining network analysis of 2.3.2.1c viruses revealed that the Dubai outbreak was an episode of a westward spread of these viruses on a larger scale from unidentified Asian sources. The incursion into Dubai, possibly via infected captive hunting falcons returning from hunting trips to central Asian countries, preceded outbreaks in Nigeria and other West African countries. The alarmingly enhanced geographical mobility of clade 2.3.2.1.c and clade 2.3.4.4 viruses may represent another wave of transcontinental dissemination of Asian-origin HPAIV H5 viruses, such as the outbreak at Qinghai Lake caused by clade 2.2 (‘Qinghai’ lineage) in 2005.

  12. 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

    Directory of Open Access Journals (Sweden)

    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.

  13. Pre-exposing Canada Geese (Branta canadensis) to a low-pathogenic H1N1 avian influenza virus protects them against H5N1 HPAI virus challenge.

    Science.gov (United States)

    Berhane, Yohannes; Embury-Hyatt, Carissa; Leith, Marsha; Kehler, Helen; Suderman, Matthew; Pasick, John

    2014-01-01

    In previous studies we examined the role of Canada Geese (Branta canadensis) in the epidemiology of Eurasian highly pathogenic avian influenza (HPAI) H5N1. To expand on this and better understand how pre-exposure to heterosubtypic low-pathogenic avian influenza (LPAI) viruses might influence the outcome of H5N1 HPAI infection, we pre-exposed naïve juvenile Canada Geese to different North American wild-bird-origin LPAI viruses. We selected H1, H2, and H6 hemagglutinin subtype viruses based on their higher-order evolutionary relatedness to the H5 hemagglutinin. Pre-exposing Canada Geese to either H2N3 or H6N5 viruses did not protect them against a lethal H5N1 HPAI virus challenge. In addition, H5N1 was transmitted to naïve control birds that were placed among both groups resulting in death by 5 days postcontact. In contrast, Canada Geese that were pre-exposed to H1N1 were protected against a lethal H5N1 challenge, shed minimal amounts of the virus into the environment, and did not transmit the infection to naïve contact birds. None of the H1N1, H2N3, or H6N5 pre-exposure sera neutralized H5N1 in vitro; however, sera from H1N1-infected birds reduced virus plaque size but not number when compared with H2N3, H6N5, or negative sera, suggesting that antibodies directed against the neuraminidase may have had a role in the protective effects observed.

  14. Progress in treatment of infection with highly pathogenic H5N1 avian influenza virus since 2005%关于WHO 2005年以来高致病性H5N1禽流感病毒的临床和治疗进展

    Institute of Scientific and Technical Information of China (English)

    杨子峰; 王丹芬; 钟南山; 陈敬贤

    2009-01-01

    自1997年中国香港特别行政区报道首例人感染H5N1禽流感病毒以来,截至2008年9月10日,这场在禽类中史无前例地持续流行、造成了人类感染并具有高病死率的疫情已经波及到15个国家和地区,总发病387例,死亡245例,其中我国疫情30例,病死率超过60%,防控形势十分严峻.本文旨在整理分析2005年以来世界卫生组织和全球对禽流感病毒临床防治研究成果及人感染H5N1禽流感病例报道的最新信息,力求提供一个防治人禽流感方面的较为全面而清晰的介绍.%Highly pathogenic H5N1 avian influenza virus(AIV) has spread unprecedentedly across the world since the first outbreak of human cases was reported in 1997 in Hong Kong, China. Until June 19th,2008,H5N1 virus resulted in sporadic but severe even fatal human cases in 15 countries,243 died in 385 reported human H5N1 infections,including 20 in China,and the overall mortality was more than 60%. These new appeared viruses and their capacity of transmission from birds to humans have raised a great deal of concern for a potential pandemic,and world health organization has promulgated a few recommendations or guidelines. This review provides an up-to-date information of research in H5N1 virus infection since 2005, and summarizes the epidemiology, clinical features, pathology, diagnosis, current therapeutic options and prevention strategies of H5N1 infection in humans.

  15. 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.

  16. 2株H5N1亚型禽流感病毒人工感染鸭的组织病理学观察%Histopathology of Ducks Experimentally Infected with Two Avian Influenza Viruses(H5N1)

    Institute of Scientific and Technical Information of China (English)

    叶远兰; 周泉鹤; 李玉谷

    2011-01-01

    鸭经肌肉接种禽流感病毒A/duck/Guangdong/185/2004(H5N1)和A/duck/Guangdong/221/2004(H5N1)后,2周内未见死亡,但具有一些显微和超微病理学变化,主要表现为呼吸道、消化道黏膜受损,心脏、肝脏、肺脏、肾脏、脑等器官一定程度的充血、淤血、出血、水肿及实质细胞变性、坏死和炎症等.%Ducks intramuscularly inoculated with two avian influenza virus isolates, A/duck/Guangdong/221/2004(HSN1)and A/duck/Guangdong/185/2004(H5N1), had micropathological and ultrapathological lessions in some degree in multiple organs, such as the damages of mucous membrane of respiratory and alimentary tract, and hyperemia, congestion, hemorrhage,edema, and cell degeneration, necrosis, inflammation or a combination of these features in the heart, liver, lung, kidney, andencephalon etc, but did not died in two weeks.

  17. Spatio-Temporal Occurrence Modeling of Highly Pathogenic Avian Influenza Subtype H5N1: A Case Study in the Red River Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    Chinh C. Tran

    2013-11-01

    Full Text Available Highly Pathogenic Avian Influenza (HPAI subtype H5N1 poses severe threats to both animals and humans. Investigating where, when and why the disease occurs is important to help animal health authorities develop effective control policies. This study takes into account spatial and temporal occurrence of HPAI H5N1 in the Red River Delta of Vietnam. A two-stage procedure was used: (1 logistic regression modeling to identify and quantify factors influencing the occurrence of HPAI H5N1; and (2 a geostatistical approach to develop monthly predictive maps. The results demonstrated that higher average monthly temperatures and poultry density in combination with lower average monthly precipitation, humidity in low elevation areas, roughly from November to January and April to June, contribute to the higher occurrence of HPAI H5N1. Provinces near the Gulf of Tonkin, including Hai Phong, Hai Duong, Thai Binh, Nam Dinh and Ninh Binh are areas with higher probability of occurrence of HPAI H5N1.

  18. Avian influenza A(H7N9) and (H5N1) infections among poultry and swine workers and the general population in Beijing, China, 2013–2015

    Science.gov (United States)

    Yang, Peng; Ma, Chunna; Cui, Shujuan; Zhang, Daitao; Shi, Weixian; Pan, Yang; Sun, Ying; Lu, Guilan; Peng, Xiaomin; Zhao, Jiachen; Liu, Yimeng; Wang, Quanyi

    2016-01-01

    Although several studies have reported seroprevalences of antibody against avian influenza A(H7N9) virus among poultry workers in southern China, results have varied and data in northern China are scarce. To understand risks of H7N9 and H5N1 virus infections in northern China, a serological cohort study was conducted. Poultry workers, swine workers and the general population in Beijing, China, were evaluated through three surveys in November 2013, April 2014 and April 2015. The highest seroprevalence to H7N9 virus among poultry workers was recorded in the April 2014 and April 2015 surveys (0.4%), while that to H5N1 clade 2.3.4 or clade 2.3.2.1 virus was noted in the April 2014 survey (1.6% and 0.2%, respectively). The incidence of H7N9 virus infections among poultry workers (1.6/1000 person-months) was significantly lower than that of H5N1 clade 2.3.4 infections (3.8/1000 person-months) but higher than that of H5N1 clade 2.3.2.1 infections (0.3/1000 person-months). Compared with the general population, poultry workers were at higher risk of contracting H7N9 virus (IRR: 34.90; p H7N9 and H5N1 virus infections remain low in Beijing, continued preventive measures are warranted for poultry workers. PMID:27670286

  19. 湖北省部分地区规模化蛋鸡场H5N1 Re-6亚型禽流感疫苗免疫效果调查%INVESTIGATION INTO FIELD EFFICACY OF H5N1 RE-6 AVIAN INFLUENZA VIRUS VACCINE ON LAYER FARMS IN HUBEI

    Institute of Scientific and Technical Information of China (English)

    汪招雄; 杨玉莹; 欧阳金旭; 杨丰利; 江涛; 陈雪娇

    2015-01-01

    禽流感(avian influenza,AI)是由A型流感病毒(Avian influenza virus,AIV)感染禽类引起的一种从呼吸系统到全身严重败血症等多种症状的高度接触性传染病.目前,对我国家禽产业危害最大的高致病性禽流感病毒是H5禽流感病毒,几乎所有的规模化蛋鸡场都进行了H5禽流感疫苗的预防接种.为了解湖北省规模化蛋鸡场H5N1 Re-6亚型疫苗免疫后抗体滴度,本研究于2014年1~12月期间在湖北省13个地区选择不同规模化蛋鸡场,随机采集2079份蛋鸡血样,用血凝抑制(hemagglutinationinhibition,HI)实验检测了H5N1 Re-6亚型禽流感抗体,并对测定结果进行了统计与分析.结果显示,规模化蛋鸡场H5N1 Re-6亚型抗体滴度在6 1og2以上的样品数占89.2%,能够保护鸡群抵抗同型病毒的感染.但H5N1 Re-6亚型禽流感抗体滴度整体不高,且仍有少量地区H5N1 Re-6亚型禽流感免疫合格率为60%~80%,提示部分鸡群一旦感染该型病毒,仍然存在发病的危险.

  20. 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

  1. Identifikasi Secara Serologi Galur Virus Flu Burung Subtipe H5N1 Clade 2.1.3 dan Clade 2.3.2 pada Ayam Petelur (SEROLOGICAL IDENTIFICATION OF AVIAN INFLUENZA STRAIN VIRUS SUBTYPE H5N1 CLADE 2.1.3 AND CLADE 2.3.2 FROM LAYER

    Directory of Open Access Journals (Sweden)

    Aprilia Kusumastuti

    2015-10-01

    Full Text Available The aim of the study was to know avian influenza (AI infection in field by using serology test in threemarketing area of AI vaccines. Haemagglutination inhibition methode was used in this test. There werefour antigen strains of AI subtype H5N1 clade 2.1.3 (AIstrainA/Chicken/West Java/PWT-WIJ/2006, AIstrain A/Chicken/Garut/BBVW-223/2007, AI strain A/Chicken/West Java-Nagrak/30/2007, and AI strainA/Chicken/Pekalongan/BBVW-208/2007 and 2 antigen strains of AI subtype H5N1 clade 2.3.2 (AI strainA/duck/Sukoharjo/BBVW-1428-9/2012 and AI strain A/duck/Sleman/BBVW-1463-10/2012 was used inthis study for HI test. The result presents that 93,33% chicken farms in three marketing area of PT. SanbioLaboratories have positive antibody titre to AI subtype H5N1 clade 2.1.3. This titre may be obtained fromAI clade 2.1.3 vaccination. From 15 samples, 92,86% are positive to AI subtype H5N1 clade 2.3.2A/duck/Sukoharjo/BBVW-1428-9/2012 and 92,31% are positive to A/duck/Sleman/BBVW-1463-10/2012 evenwithout AI clade 2.3.2 vaccination. This antibody titre may be obtained from AI clade 2.1.3 vaccine crossprotection or field infection.

  2. Evaluation of antibody response in mice against avian influenza A (H5N1) strain neuraminidase expressed in yeast Pichia pastoris

    Indian Academy of Sciences (India)

    Murugan Subathra; Ponsekaran Santhakumar; Mangamoori Lakshmi Narasu; Syed Sultan Beevi; Sunil K Lal

    2014-06-01

    Avian influenza has raised many apprehension in the recent years because of its potential transmitability to humans. With the increasing emergence of drug-resistant avian influenza strains, development of potential vaccines are imperative to manage this disease. Two structural antigens, haemagglutinin and neuraminidase, have been the target candidates for the development of subunit vaccine against influenza. In an effort to develop a faster and economically beneficial vaccine, the neuraminidase gene of a highly pathogenic avian influenza isolate was cloned and expressed in the methylotrophic yeast Pichia pastoris. The recombinant neuraminidase (rNA) antigen was purified, and its bioactivity was analysed. The rNA was found to be functional, as determined by the neuraminidase assay. Four groups of mice were immunized with different concentrations of purified rNA antigen, which were adjuvanted with aluminium hydroxide. The immune response against rNA was analysed by enzyme-linked immunosorbent assay (ELISA) and neuraminidase inhibition assay. The mice groups immunized with 25 g and 10 g of antigen had a significant immune response against rNA. This method can be utilized for faster and cost-effective development of vaccines for a circulating and newer strain of avian influenza, and would aid in combating the disease in a pandemic situation, in which production time matters greatly.

  3. A review of highly pathogenic avian influenza in birds, with an emphasis on Asian H5N1 and recommendations for prevention and control.

    Science.gov (United States)

    Kelly, Terra R; Hawkins, Michelle G; Sandrock, Christian E; Boyce, Walter M

    2008-03-01

    Avian influenza is a disease of both veterinary and public health importance. Influenza A viruses infect a range of hosts, including humans, and can cause significant morbidity and mortality. These viruses have high genetic variability, and new strains develop through both mutation and reassortment. Modes of transmission as well as the location of viral shedding may differ both by host species and by viral strain. Clinical signs of influenza A virus infection in birds vary considerably depending on the viral subtype, environmental factors, and age, health status, and species of the bird and range from decreased egg production and gastrointestinal manifestations to nervous system disorders and respiratory signs. Most commonly, peracute death with minimal clinical disease is observed in poultry infected with a highly pathogenic avian influenza virus. There are various prevention and control strategies for avian influenza, including education, biosecurity, surveillance, culling of infected animals, and vaccination. These strategies will differ by institution and current federal regulations. Each institution should have an established biosecurity protocol that can be properly instituted. Lastly, human health precautions, such as proper hand hygiene, personal protective equipment, and employee health monitoring, are imperative for at-risk individuals.

  4. Highly pathogenic avian influenza virus H5N1 controls type I IFN induction in chicken macrophage HD-11 cells: a polygenic trait that involves NS1 and the polymerase complex

    Directory of Open Access Journals (Sweden)

    Liniger Matthias

    2012-01-01

    Full Text Available Abstract Background Influenza A viruses are well characterized to antagonize type I IFN induction in infected mammalian cells. However, limited information is available for avian cells. It was hypothesised that avian influenza viruses (AIV with distinct virulence may interact differently with the avian innate immune system. Therefore, the type I IFN responses induced by highly virulent and low virulent H5N1 AIV and reassortants thereof were analysed in chicken cells. Results The highly pathogenic (HP AIV A/chicken/Yamaguchi/7/04 (H5N1 (Yama did not induce type I IFN in infected chicken HD-11 macrophage-like cells. This contrasted with an NS1 mutant Yama virus (Yama-NS1A144V and with the attenuated H5N1 AIV A/duck/Hokkaido/Vac-1/04 (Vac carrying the haemagglutinin (HA of the Yama virus (Vac-Yama/HA, that both induced type I IFN in these cells. The substitution of the NS segment from Yama with that from Vac in the Yama backbone resulted in induction of type I IFN secretion in HD-11 cells. However, vice versa, the Yama NS segment did not prevent type I IFN induction by the Vac-Yama/HA virus. This was different with the PB1/PB2/PA segment reassortant Yama and Vac-Yama/HA viruses. Whereas the Yama virus with the Vac PB1/PB2/PA segments induced type I IFN in HD-11 cells, the Vac-Yama/HA virus with the Yama PB1/PB2/PA segments did not. As reported for mammalian cells, the expression of H5N1 PB2 inhibited the activation of the IFN-β promoter in chicken DF-1 fibroblast cells. Importantly, the Yama PB2 was more potent at inhibiting the IFN-β promoter than the Vac PB2. Conclusions The present study demonstrates that the NS1 protein and the polymerase complex of the HPAIV Yama act in concert to antagonize chicken type I IFN secretion in HD-11 cells. PB2 alone can also exert a partial inhibitory effect on type I IFN induction. In conclusion, the control of type I IFN induction by H5N1 HPAIV represents a complex phenotype that involves a particular viral

  5. 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

    Objective To investigate the risk of H5Nl subtype avian influenza virus (AIV)transmission in the poultry market environment in Changsha city.H5N1 antibody levels among the groups related occupational exposure and AIV nucleic acid in the environment of poultry markets were detected.The characteristics of hamagglutinin (HA) genes of H5N1 AIV in the environment were analyzed.Methods One district and one county from Changsha city were selected randomly and two poultry markets at inner city or township levels were selected in the same district or county respectively.H5N1 antibody of the occupational exposure groups in the poultry market was tested and AIV nucleic acid in the poultry market environnent monitored.One hundred and two blood samples of the occupational exposure groups were tested for H5N1 antibody with single radioimmunoassay diffusion hemolysis (SRH) while 160 environment samples(from sewage,birds stools,feathers and smearing samples of poultry cages) in the poultry market were also detected for AIV nucleic acid with real-time PCR method.Four sewage samples of H5N1 subtype AIV were collected from poultry markets in Changsha,and the HA genes of H5N1 subtype AIV amplified by RT-PCR and then sequenced with TA cloning.Amino acid sequence alignment and phylogenetic tree analysis were conducted by Lasergene and Mega 5.0 software.Results The results through H5N1 antibody monitoring program showed that H5N1 antibody positive rates from workers were 25.5% (26/102),50.0% (9/18) and 25.4% (17/67) respectively in the poultry markets of township and inner cities.H5N1 antibody positive rate in the township poultry markets was higher than in the inner cities poultry markets.Results from the surveillance on AIV nucleic acid showed that the overall H5 subtype positive rate in Changsha poultry markets was 31.3% (50/160),and the positive rate of townships poultry markets was 37.3% (31/83 ),which were both higher than those from the inner cities poultry markets (24

  6. 武汉市外环境中禽流行性感冒病毒分布及禽类职业暴露人群H5N1抗体水平调查%Investigation on the distribution of avian influenza virus in external environment and the level of H5N1 antibody in poultry-exposed population in Wuhan

    Institute of Scientific and Technical Information of China (English)

    王英; 孔雯骅; 朱洪浩; 罗同勇; 林新明; 余滨; 陈邦华; 胡权; 彭劲松

    2011-01-01

    of influenza A subtypes in external environment and investigate the infectious status of highly pathogenic avian influenza (H5N1) in poultry-exposed population in Wuhan.Methods Seventy-eight external environmental samples (water,cage surface and fecal samples) were collected from 3 habitats of wild migratory birds and 5 urban live-poultry markets in 2010.In 13 avian influenza monitoring points,249 serum samples were collected from people living around habitats of wild migratory birds or working in live poultry markets.Real-time RT-PCR method was adopted to detect influenza A virus from external environmental samples; and multiple RT-PCR method and specific H3,H5,H7 and H9 primers were then applied to analyze the subtypes of the positive samples.The levels of H5N1 antibody in poultry-exposed population were tested by horse hemagglutination inhibition test and two avian influenza inactivated antigens:A/Hubei/1/10 and A/Anhui/1/05.Results Of the 50 external environmental samples collected from live poultry markets,17 samples were determined to be influenza A virus positive (positive rate 34.0% ),including specific subtypes as follows:4 samples of H5 single-positive subtype,3 samples of H9 single-positive subtype,4 samples of H3 and H5 mixed-positive subtype,2 samples of H3 and H9 mixed-positive subtype,2 samples of H5 and H9 mixed-positive subtype,2 samples of H3,H5 and H9 mixed-positive subtype,but no H7 positive subtype was found.The 28 external environmental samples collected from habitats of wild migratory birds were all influenza A virus negative.Considering different types of external environmental samples,the influenza A virus positive rates in water,cage surface and fecal samples were 37.5% ( 6/16 ),16.7% ( 5/30 ) and 18.8% ( 6/32 ),respectively.There were total 100 samples of serum whose A/Hubei/1/10 antigen inhibiting titers ≥40,accounting for 40.2% ; while 36 samples of serum ( 14.5% ) whose A/Anhui/1/05 antigen inhibiting titers ≥ 40 were

  7. H5N1亚型禽流感病毒低剂量感染小鼠发病模型的建立%Pathogenicity of a low-dosage inoculation of H5N1 avian influenza virus in mice

    Institute of Scientific and Technical Information of China (English)

    李旭勇; 郭晶; 施建忠; 李雁冰; 陈化兰

    2011-01-01

    为模拟哺乳动物感染H5亚型高致病性禽流感病毒(HPAIV)的发病进程,本研究采用对哺乳动物高度致病的H5N1亚型HPAIV株A/bar-headed goose/Qinghai/3/05 (BHG/3/05),以低剂量鼻腔接种小鼠,观察发病、存活、病毒复制及组织病理损伤情况.结果显示,100.4 EID50即能够100%感染小鼠,但发病表现缓慢,死亡延迟至8d以后,存活达60%;体内病毒复制可持续10 d以上,感染后前3d病毒的增殖限于呼吸道,随后扩散至脑、脾、肾等其他器官;组织病理学观察肺脏早期表现出渗出性炎症,第10d发展为典型的间质性肺炎.本研究结果为探讨人禽流感的病理发生机制提供了具有价值的模型.%To imitate the natural infection of H5N1 subtype avian influenza virus (AIV) in animals, BALB/c mice were inoculated with a low-dosage (100.4 EID50) of H5N1 AIV A/bar-headed goose/3/05 (BHG/3/05) strain and were observed for weight gain and mortality. Different organs of the mice were also collected at different time points after infection for virus titration and pathologic examination. The results indicated that all of the inoculated mice were successfully infected by the virus, and 60% of mice survived during the 2 weeks observation period. Virus could be detected from organs of mice at 3, 5, 7, and 10 days, but not at 14 days post infection (p.I.). The virus was only detected in the lung of mice on day 3 p.I., then gradually spread to spleen, kidney and brain. Histopathologic examination revealed the pneumonia with significant infiltration of inflammatory cells in the lung section at day 3 p.I., and interstitial pneumonia at day 10 p.I.. These results are useful for a better understanding of the pathogenesis of H5N1 influenza virus infection in nature.

  8. Addition of N-glycosylation sites on the globular head of the H5 hemagglutinin induces the escape of highly pathogenic avian influenza A H5N1 viruses from vaccine-induced immunity.

    Science.gov (United States)

    Hervé, Pierre-Louis; Lorin, Valérie; Jouvion, Grégory; Da Costa, Bruno; Escriou, Nicolas

    2015-12-01

    Highly pathogenic avian influenza A H5N1 viruses remain endemic in poultry in several countries and still constitute a pandemic threat. Since the early 20th century, we experienced four influenza A pandemics. H3N2 and H1N1pdm09 viruses that respectively emerged during 1968 and 2009 pandemics are still responsible for seasonal epidemics. These viruses evolve regularly by substitutions in antigenic sites of the hemagglutinin (HA), which prevent neutralization by antibodies directed against previous strains (antigenic drift). For seasonal H3N2 viruses, an addition of N-glycosylation sites (glycosites) on H3 contributed to this drift. Here, we questioned whether additional glycosites on H5 could induce an escape of H5N1 virus from neutralization, as it was observed for seasonal H3N2 viruses. Seven H5N1 mutants were produced by adding glycosites on H5. The most glycosylated virus escaped from neutralizing antibodies, in vitro and in vivo. Furthermore, a single additional glycosite was responsible for this escape.

  9. Identification of potential risk factors associated with highly pathogenic avian influenza subtype H5N1 outbreak occurrence in Lagos and Kano States, Nigeria, during the 2006-2007 epidemics.

    Science.gov (United States)

    Métras, R; Stevens, K B; Abdu, P; Okike, I; Randolph, T; Grace, D; Pfeiffer, D U; Costard, S

    2013-02-01

    Highly pathogenic avian influenza HPAI H5N1 was first reported in Africa in 2006, in Nigeria. The country experienced severe outbreaks in 2006 and 2007, strongly affecting the poultry population. Current knowledge on potential risk factors for HPAI H5N1 occurrence in poultry farms in Nigeria is limited. Therefore, we conducted a case-control study to identify potential farm-level risk factors for HPAI H5N1 occurrence in two areas of the country that were affected by the disease in 2006 and 2007, namely the States of Lagos and Kano. A case-control study was conducted at the farm level. A convenience sample of 110 farms was surveyed. Data on farm characteristics, farm management and trade practices were collected. Logistic regression was used to identify factors associated with farms that confirmed positive for HPAI. Having a neighbouring poultry farm was identified as a potential risk factor for disease occurrence [OR, 5.23; 95% CI, (0.88-30.97); P-value = 0.048]. Farm staff washing their hands before handling birds was a protective factor [OR, 0.14; 95% CI, (0.05-0.37); P-value prevention in Kano and Lagos States. Despite the limitations owing to the sampling strategy, these results are consistent with other risk factor studies previously conducted on HPAI H5N1 in both Africa and other regions, suggesting similar risk factor patterns for HPAI H5N1 virus spread and substantiating current knowledge regarding the epidemiology of the disease. Finally, this study generated information from areas where data are difficult to obtain.

  10. 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...

  11. 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

  12. 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

  13. 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.

  14. A triclade DNA vaccine designed on the basis of a comprehensive serologic study elicits neutralizing antibody responses against all clades and subclades of highly pathogenic avian influenza H5N1 viruses.

    Science.gov (United States)

    Zhou, Fan; Wang, Guiqin; Buchy, Philippe; Cai, Zhipeng; Chen, Honglin; Chen, Zhiwei; Cheng, Genhong; Wan, Xiu-Feng; Deubel, Vincent; Zhou, Paul

    2012-06-01

    Because of their rapid evolution, genetic diversity, broad host range, ongoing circulation in birds, and potential human-to-human transmission, H5N1 influenza viruses remain a major global health concern. Their high degree of genetic diversity also poses enormous burdens and uncertainties in developing effective vaccines. To overcome this, we took a new approach, i.e., the development of immunogens based on a comprehensive serologic study. We constructed DNA plasmids encoding codon-optimized hemagglutinin (HA) from 17 representative strains covering all reported clades and subclades of highly pathogenic avian influenza H5N1 viruses. Using DNA plasmids, we generated the corresponding H5N1 pseudotypes and immune sera. We performed an across-the-board pseudotype-based neutralization assay and determined antigenic clusters by cartography. We then designed a triclade DNA vaccine and evaluated its immunogenicity and protection in mice. We report here that (sub)clades 0, 1, 3, 4, 5, 6, 7.1, and 9 were grouped into antigenic cluster 1, (sub)clades 2.1.3.2, 2.3.4, 2.4, 2.5, and 8 were grouped into another antigenic cluster, with subclade 2.2.1 loosely connected to it, and each of subclades 2.3.2.1 and 7.2 was by itself. Importantly, the triclade DNA vaccine encoding HAs of (sub)clades 0, 2.3.2.1, and 7.2 elicited broadly neutralizing antibody responses against all H5 clades and subclades and protected mice against high-lethal-dose heterologous H5N1 challenge. Thus, we conclude that broadly neutralizing antibodies against all H5 clades and subclades can indeed be elicited with immunogens on the basis of a comprehensive serologic study. Further evaluation and optimization of such an approach in ferrets and in humans is warranted.

  15. Hemagglutinin protein of avian influenza virus H5N1 in immune injury of peripheral immune organs and its possible mechanism%H5N1病毒HA蛋白对小鼠外周免疫器官的损伤及其机制

    Institute of Scientific and Technical Information of China (English)

    葛南海; 胥韦; 陈敏惠; 徐军

    2012-01-01

    This study aims to investigate the role of recombinant hemagglutinin protein (HA) of avian influenza virus (AVI) H5N1 in immune injury of peripheral immune organ spleen and the related cytokines secretion in mice. By using insect-baculovirus expression system and nickel affinity magnet beads, HA protein of AVI H5N1 was recombined and was used in mice. Seventy-two hours after HA protein instillation, the lungs and spleens were isolated form the mice. Pathological examination revealed spleen swelling, destruction of local structure of germinal center, vacuolar changes and a decrease in lymphocyte, while lung pathological examination showed diffuse alveolar damage, inflammatory cell infiltration in mice challenged by HA. The injury index of spleen cells after LPS stimulation in HA pretreatment was higher than that in those of PBS pretreatment. And under basal condition, the levels of IP-10, MCP-la and Rantes released from the spleen cells of mice in HA pretreatment were significantly higher than those from the mice of PBS pretreatment group (P< 0.05). Twenty-four hours after LPS stimulation, the levels of IFN-γ, IP-10, MCP-la, and Rantes released from the spleen cells of HA pre-treated mice was significantly higher than those from PBS pretreated mice (P< 0.05). In conclusion, the H5N1 virus HA membrane protein by intratracheal instillation elicits a strong pathological immune response in the host, resulting in immune injury of peripheral lymphoid organs and immune cells and acute lung injury.%目的 研究H5N1病毒HA蛋白作用于小鼠后对其外周免疫器官脾脏的损伤其相关细胞因子的分泌.方法 通过昆虫-杆状病毒表达系统表达H5N1病毒HA蛋白,并经镍亲和磁珠纯化,将重组的HA蛋白作用于小鼠,72 h后,取其脾脏,观察其镜下形态学变化;分离脾细胞并培养,检测其细胞因子的分泌.结果 脾组织病理表现为局部性弥漫性肺泡损伤,单核细胞侵润,脾脏肿胀,毛细血管充血,生发

  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. 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.

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

    Science.gov (United States)

    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.

  19. 禽流感病毒H5N1基因突变对神经氨酸酶抑制剂敏感性和神经氨酸酶活性的影响%Impact of avian influenza virus H5N1 neuraminidase mutations on the activity of neuraminidase and the sensibility to neuraminidase inhibitors

    Institute of Scientific and Technical Information of China (English)

    谌资; 郑煜煌; Yipu Lin; Patrick J Collins; Alan J Hay

    2010-01-01

    Objective To study the impact of avian influenza virus H5N1 neuraminidase mutations I117V,I314V and I117V+I314V on the sensibility of neuraminidase inhibitors(NAIs) and the activity of neuraminidase (NA).Methods The mutations were intreduced into NA genes of virus strain A/Vietnam/1203/04 (H5N1)by site-directed mutagenesis.With the A/WSN/33 (H1N1)background,recombinant influenza viruses containing NA mutations were rescued by reverse genetics.After viral propagation in chicken embryos,fluorimetric assays were conducted to assess the sensibility to NAIs and NA activity(IC50,Km&Ki).Results Compared to the wild-type viruS VNl203.the mutation I117V decreased the susceptibility to osehamivir(17-fold increment of IC50 value,20-fold increment of Ki value)and the NA activity(23-fold increment of Km value)while there Was little impact on zanamivir sensitivity(2-fold increment of IC50 value,3-fold increment of Ki value).The mutation 1314V had no marked influence on either the NA activity or the NAIs susceptibility.Conclusion It aDpears that the NA mutations of I117V and I314V Can not cause NAIs resistanee.Oseltamivir or zanamivir may still be prescribed for anti-viral treatment.%目的 研究感染人的禽流感病毒H5N1神经氨酸酶突变I117V,I314V,I117V+I314V对神经氨酸酶抑制剂(NAIs)敏感性和神经氨酸酶(NA)活性的影响.方法 定点突变技术将变异位点引入禽流感病毒株A/Vietnam/1203/04(H5N1)(VN1203)的NA基因中,以A/WSN/33(H1N1)为背景,通过反向遗传学方法构建重组流感病毒,鸡胚传代增殖病毒,荧光定量评估病毒对NAIs的敏感性和NA活性(IC50值和Km,Ki值).结果 与野生株VN1203相比,I117V使NA对奥司他韦敏感性降低(IC50值升高了17倍,Ki值升高了20倍),对扎那米韦敏感性无明显影响(IC50值升高了2倍,Ki值升高了3倍),NA活性降低(Km值升高了23倍).I314V对NAIs敏感性和NA活性均无明显影响.结论 初步结果认为NA突变I117V和I314V对感染人的禽流感病毒H

  20. 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.

  1. 禽流感病毒H5N1亚型基因工程疫苗设计、表达制备及动物实验研究%Preparation of avian influenza virus H5N1 genetic engineering vaccine and animal study

    Institute of Scientific and Technical Information of China (English)

    刘学东; 包振民; 王志亮

    2011-01-01

    目的 设计并获得一种安全、高效,并能对以H5N1亚型为主的多种禽流感病毒亚型产生保护的复合基因工程疫苗.方法 利用分子生物学和分子免疫学方法对国内以及周边国家流行的禽流感毒株进行全面分析,利用生物信息学技术合理设计亚单位加表位的全新复合结构疫苗的氨基酸序列;利用大肠杆菌密码子优化技术根据疫苗氨基酸序列获得基因序列;通过全基因合成的方法获得该疫苗的基因,并通过大肠杆菌表达系统对该疫苗进行表达;目的蛋白经过包涵体洗涤和色谱纯化后复性;通过ELISA评价其抗原特异性,并乳化制备成禽流感蛋白疫苗,通过小鼠体内免疫试验检测其免疫效力.结果 设计了包含通用性的辅助性T细胞表位、B细胞表位以及CTL表位的串接疫苗结构;全基因合成获得了该复合疫苗的基因序列;该基因在大肠杆菌表达系统中得到了高效表达,目的蛋白表达量约占菌体总蛋白30%;经过粗纯和精纯后的目的蛋白纯度达到95.5%,复性后获得可溶性蛋白溶液,浓度可达2.4 mg/mL.结论 通过小鼠实验,验证了该H5N1亚型基因工程疫苗的抗原性,证实该基因工程疫苗在免疫小鼠体内激发体液免疫的同时调动了细胞免疫.小鼠免疫试验证明,该疫苗可以在小鼠体内有效诱发免疫应答.%Objective To design and prepare a genetic engineering vaccine against avian influenza virus H5N1. Methods The composite amino acid sequences plus epitope subunit of vaccine were designed based on the analysis of prevalent avian influenza H5N1 strains and bioinformatics. The amino acid sequence was obtained with E. Coli codon optimization technique; the vaccine gene was synthesized with the whole gene synthesis method and expressed with E. Coli expression system. Theprotein inclusion bodies were purified by renaturation chromatography after washing; the antigen specificity was

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Screening of Proteins Interacting with Nonstructural 1 Protein of H5N1 Avian Influenza Virus from T7-phage Display Library

    Institute of Scientific and Technical Information of China (English)

    ZHU Chun-yu; WU Jian-guo; LIU Hong-sheng; SUN Ting-ting; ZHAO Jian; WANG Ning; ZHENG Fang-liang; AI Hai-xin; ZHU Jun-feng; WANG Xiao-ying; ZHU Ying

    2012-01-01

    Avian influenza virus(AIV) nonstructural 1(NS1) gene was amplified by real-time polymerse chain reaction(RT-PCR) and inserted into pET28a,then transformed into E.coli BL21(DE3) competent cell.With the induction of isopropyl-β-D-thiogalactoside(IPTG) and the purification of Ni-NTA column,we finally obtained purified NS1 protein.T7-phage display system was used to screen the proteins that interacted with NS1 from lung cell cDNA library.The selected positive clones were identified by DNA sequencing and analyzed by BLAST program in GeneBank.Two proteins were obtained as NS 1 binding proteins,Homo sapiens nucleolar and coiled-body phosphoprotein 1(NOLC1) and Homo sapiens similar to colon cancer-associated antigen.By co-immunoprecipitation and other methods,Homo sapiens NOLC1 was found to interact with the NS1 protein,the results would provide the basis for further studying biological function of NS1 protein.

  4. Husbandry Practices and Outbreak Features of Natural Highly Pathogenic Avian Influenza H5N1 in Turkey Flocks in Nigeria 2006-2008

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    Olatunde Babatunde Akanbi

    2015-12-01

    Full Text Available The Highly Pathogenic Avian Influenza (HPAI outbreaks in Nigeria that occurred during 2006-2008, affected 80 farms that kept subsistence indigenous chicken, duck, turkey, guinea fowl and geese in 15 states of the country including the capital, Abuja resulting in a total loss of more than 14,000 birds in backyard, semi-intensive or free-ranged flocks. The rearing of rural poultry in free-range, multispecies, multiage holdings that have low biosecurity levels have shown to expose them to many contact risks. In order to sustain turkey production in the country in view of the ongoing resurgent HPAI outbreaks, it is necessary to assess the impact of HPAI on this species and to evaluate the husbandry and outbreak features of affected flocks. Spatial data confirmed the presence of HPAI virus in both domestic and commercial poultry farms from 25 States and the Federal Capital Territory (FCT in Nigeria were added to a Geographical Information System (GIS using ESRI ArcGIS 10.3 (ESRI®, USA and QGIS 2.8.2 Desktop (OSGeo and visualized using QGIS. Post mortem examinations of submitted carcasses were carried out and swabs and tissues were analyzed by virus isolation (VI and reverse transcriptase polymerase chain reaction (RT-PCR. HPAI in turkey flocks were mostly in northern part of the country where most poultry mainly subsistence are domiciled and are more in the densely cities of the north. The poultry management systems employed by the subsistence turkey farmers were mainly semi-intensive backyard and free-ranged system of poultry. HPAI introduction sources vary from the introduction of new poultry species (geese and turkey from LBM, to the death of neighborhood poultry and extension to turkey flocks and/or contact with free-ranging local chickens. It is obvious that the husbandry and the management system had influenced on the introduction of the virus and the course of the disease.

  5. PA-X-associated early alleviation of the acute lung injury contributes to the attenuation of a highly pathogenic H5N1 avian influenza virus in mice.

    Science.gov (United States)

    Hu, Jiao; Mo, Yiqun; Gao, Zhao; Wang, Xiaoquan; Gu, Min; Liang, Yanyan; Cheng, Xin; Hu, Shunlin; Liu, Wenbo; Liu, Huimou; Chen, Sujuan; Liu, Xiaowen; Peng, Daxing; Liu, Xiufan

    2016-08-01

    PA-X is a novel discovered accessory protein encoded by the PA mRNA. Our previous study demonstrated that PA-X decreases the virulence of a highly pathogenic H5N1 strain A/Chicken/Jiangsu/k0402/2010 in mice. However, the underlying mechanism of virulence attenuation associated with PA-X is still unknown. In this study, we compared two PA-X-deficient mutant viruses and the parental virus in terms of induction of pathology and manipulation of host response in the mouse lung, stimulation of cell death and PA nuclear accumulation. We first found that down-regulated PA-X expression markedly aggravated the acute lung injury of the infected mice early on day 1 post-infection (p.i.). We then determined that loss of PA-X expression induced higher levels of cytokines, chemokines and complement-derived peptides (C3a and C5a) in the lung, especially at early time point's p.i. In addition, in vitro assays showed that the PA-X-deficient viruses enhanced cell death and increased expression of reactive oxygen species (ROS) in mammalian cells. Moreover, we also found that PA nuclear accumulation of the PA-X-null viruses accelerated in MDCK cells. These results demonstrate that PA-X decreases the level of complement components, ROS, cell death and inflammatory response, which may together contribute to the alleviated lung injury and the attenuation of the virulence of H5N1 virus in mice.

  6. Pathology of Chicken Experimentally Infected with a Avian Influenza Virus,A/goose/Guangdong/2/1996 (H5N1)%一株鹅源H5N1亚型禽流感病毒人工感染鸡的理学研究

    Institute of Scientific and Technical Information of China (English)

    叶远兰; 刘启宏; 李玉谷

    2012-01-01

    鸡肌肉接种鹅源禽流感病毒A/goose/Guangdong/2/1996 (H5N1)后,引起约70%发病率和60%死亡率,并表现出一些显微和超微病理学变化,主要为全身性充血、淤血、出血和血栓形成,多种器官的细胞变性、坏死、炎症,以及胰腺、肾脏、肝脏、心脏、肺脏、脑、肠、胸腺、脾脏、法氏囊等的细胞凋亡.%Chickens intramuscularly inoculated with a avian influenza virus, A/goose/Guangdong/2/1996(H5Nl) .produced approximately 70% of morbidity and 60% of mortality, and had micropathological and ultrapathological lessions in some degree in multiple organs,such as, systemic hyperemia, congestion, haemorrhage, thrombosis, and cell degeneration,necrosis,and inflammation etc. As well as apoptosis was detected in pancreas, kidney, liver, heart, lung, cerebrum, intestines, thymus, spleen and bursa of fabricius etc.

  7. Knowledge, attitudes and practices towards avian influenza A (H5N1) among Cambodian women:A cross-sectional study

    Institute of Scientific and Technical Information of China (English)

    Mav Khun; Chantha Heng; Md Harun-Or-Rashid; Hideki Kasuya; Junichi Sakamoto

    2012-01-01

    Objective:To measure highly pathogenic avian influenza(HPAI)-related knowledge, attitudes, and practices(KAPs) amongCambodian women.Methods:This cross-sectional study selected 246 married women aged between18-55 years who had backyard poultry and lived at least one year in the areas of the survey through multi-stage cluster sampling.An average score of correct answers was generated to evaluate respondents’ knowledge(Good/Poor), attitudes(Positive/Negative), and practices(Good/Bad).Results:We reported that about half of the respondents had good knowledge and good practices and four-fifth of them had positive attitudes towards HPAI.Odds ratios(ORs) and95% confidence intervals(CIs) were estimated through a logistic regression model to explore contributing factors that raise theirKAP levels.Most ofthe sources were significant in increasing knowledge of the respondent, like television(OR=1.6,95%CI=1.0-2.7), radio(OR=2.5,95%CI=1.3-4.9), leaflets/booklets(OR=2.1,95%CI=1.2-3.9), school students (OR=18.4,95%CI=2.4-142.9), village health volunteers(OR=4.5,95%CI=2.2-10.9)etc.Factors such as television(OR=3.7,95%CI=2.1-6.4), leaflets/booklets(OR=2.6,95%CI=1.4-5.1), and public health staff(OR=2.2,95%CI=1.2-4.1) had similar influence on practices.Although, we found similar effect on raising the attitudes of the responded, it was not significant.Conclusions:We report a satisfactory level of positive attitudes, and moderate level of knowledge and practices related toHPAI amongCambodian women.RaisingKAPs through television, radio and other medias may be more efficient than using usual information, education and communication materials to preventHPAI.

  8. Apoptosis in the immune organs of chickens infected with H5N1 avian influenza virus derived from goose%鹅源H5N1亚型禽流感病毒感染雏鸡免疫器官细胞凋亡的研究

    Institute of Scientific and Technical Information of China (English)

    张瑞莉; 刘明; 张卓; 郑世民

    2011-01-01

    To investigate the apoptosis in the immune organs of chickens infected with H5N1 avian influenza virus (AIV) derived from goose. Fifty one-day-old specific-pathogen-free chickens were divided randomly into two groups, infected group (Ⅰ group) and control group (C group). Ⅰ group chickens were inoculated with 0.1 mL(105 TCID50) of H5N1 AIV on 7 days old by nasal, eye and oral route simultaneously. The thymus, bursa and spleen from two groups of chickens were taken at 3, 4, 5, 7 and 14 day post inoculation (dpi), respectively. The apoptosis in those organs was assayed by the terminal deoxyuridine transferase nick-end labeling and transmission electron microscope (TEM). The result showed that apoptotic cell number in thymus and spleen were significantly higher than that of C group (p<0.01) from 3 dpi to 7 dpi. Furthermore, apoptotic cell number in bursa was obviously higher than C group (p<0.05 or p<0.01) from 3 dpi to 4 dpi. TEM showed that a large number of typical apoptosis cells appeared in the thymus, bursa and spleen, with the morphological characteristics of condensation of nuclear chromatin into dense masses, followed by its margin adjacent to nuclear membrane, and concentration of cytoplasm. These results suggested that goose origin H5N1 AIV could cause apoptosis in the immune organs of infected chickens.%为研究鹩源H5NI亚型禽流感病毒(AIV)人工感染雏鸡免疫器官细胞凋亡的动态变化,本研究将50只1日龄SPF雏鸡随机分为两组,试验组雏鸡于7日龄,分别经鼻、眼、口同时感染10 TCID的鹅源H5N1亚型AIV,分别于感染后3 d、4 d、5 d、7 d和14 d迫杀,采取胸腺、法氏囊和脾脏,应用TUNEL染色法和透射电镜技术观察其细胞凋亡的动态变化情况.结果显示,试验组雏鸡的胸腺和脾脏凋亡细胞数量在感染后3 d~7 d极显著高于对照组(p<0.01);法氏囊凋亡细胞数量在感染后3 d~4 d比对照组明显增加(p<0.05或p<0.01).组织器官超微结构检

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

    Science.gov (United States)

    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...

  10. 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

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    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.

  11. 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.

  12. Evaluation of two commercial lateral flow devices (LFDs) used for flockside testing of H5N1 highly-pathogenic avian influenza infections in backyard gallinaceous poultry in Egypt.

    Science.gov (United States)

    Soliman, Mohammed; Selim, Abdullah; Coward, Vivien J; Hassan, Mohammed K; Aly, Mona M; Banks, Jill; Slomka, Marek J

    2010-10-13

    Quickvue and Anigen lateral flow devices (LFDs) were evaluated for detection of H5N1 highly pathogenic avian influenza (HPAI) infections in Egyptian poultry. Sixty five chickens and two turkeys were sampled in eight flocks where H5N1 HPAI infection was suspected. Swabs (tracheal and cloacal) and feathers were collected from each bird for flockside testing by the two LFDs. The same clinical specimens were transported for laboratory testing by M gene RRT PCR where a positive result by this "gold standard" test for one or both swabs from a given bird indicated infection at the bird level, showing 57 birds (including 15 carcassess) to be truly AI infected. Among these 57, similar bird-level LFD testing of swabs showed 43 and 44 to be AI infected by Quickvue and Anigen LFDs, respectively. Nine birds were AI negative by M gene RRT PCR and both LFDs, and one was M gene RRT PCR negative but positive by both LFDs, suggesting one false positive LFD result. Sensitivities of the LFDs relative to M gene RRT PCR were 77.2% for Anigen and 75.4% for Quickvue tests, with 90.0% specificity for both. By including feathers with swabs for LFD testing, the number of LFD positives among 57 infected birds increased by four to 48 by Anigen and 47 by Quickvue, increasing the sensitivity of the LFDs to 84.2% and 82.5% for Anigen and Quickvue, respectively. Although LFD sensitivity cannot compare to the high sensitivity displayed by validated AI RRT PCRs, they may be utilised for flockside testing of birds infected with HPAI at the peak of viral shedding, when birds are displaying advanced clinical signs or sampled as fresh carcasses. Swabs are classic field specimens collected from outbreaks, but inclusion of feathers from birds infected with H5N1 HPAI increased LFD sensitivity. However, the LFD false positive observation emphasises the importance of returning samples for confirmatory laboratory testing.

  13. Establishment and application of neutralization assay based on H5N1 avian influenza pseudotyped virus in vitro%H5N1禽流感假病毒体外中和试验技术平台的建立与应用

    Institute of Scientific and Technical Information of China (English)

    张国良; 周伯平; 蔡车国; 陈心春; 杨桂林; 陆坚; 聂广; 周保罗

    2011-01-01

    目的 建立H5N1禽流感假病毒的体外中和试验技术平台,并系统评价2份H5N1人禽流感患者恢复期血清的中和效价.方法 通过磷酸钙沉淀法将转移载体pHR-Luc、包装载体pCMV△8.2和包膜载体CMV/R-SZ(或CMV/R-TH)共转染人胚肾细胞(293T),72 h后收集假病毒上清液,免疫印迹(Western blot)鉴定假病毒颗粒HA、P24蛋白的表达,并取200μL假病毒上清液测定感染活性.收集制备假病毒过程中整合HA蛋白的293T细胞,通过流式细胞术测定2份恢复期血清中的HA抗体.利用2份恢复期血清分别与深圳株和泰国株假病毒进行中和试验,通过计算IC5o判断不同血清对2株假病毒中和效价的差异.结果 构建的2株假病毒颗粒不仅含有HIV基质蛋白P24,还可以整合HA蛋白,并且能够由前体蛋白HA0裂解为具有生物活性的HA1和HA2.200μL假病毒上清液感染靶细胞后RLA值约为2×104,具有较高的感染效价.FACS检测结果显示2份血清中均含有HA抗体,而且对不同分枝的假病毒具有交叉反应性.中和试验表明2份血清对深圳株和泰国株假病毒均具有中和能力,而且对不同分枝的假病毒具有交叉中和活性,但对深圳株的中和效价均高于泰国株.结论 本研究成功构建具有感染活性的深圳株和泰国株H5N1禽流感假病毒,并可以快速、安全、高效的评价血清的中和效价,具有广阔的应用前景.%Objective To establish neutralization assay based on H5N1 avian influenza pseudotyped virus in vitro and to evaluate neutralizing titer of convalescent serum from 2 patients with H5N1 avian influenza.Methods pHR-Luc,pCMV△8.2 and CMV/R-SH or CMV/R-TH were cotransfected into 293T cell by co-precipitation with calcium phosphate.Pseudotyped virus supernatant was harvested 72 h posttranofection and identified the expression of HA and P24 by Western blot,and then we analyzed infective activity of 200 μL supernatant of pseudotyped virus.293T cell

  14. Induction of long-term protective immune responses by influenza H5N1 virus-like particles.

    Directory of Open Access Journals (Sweden)

    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.

  15. Efficacy of a Recombinant Turkey Herpesvirus H5 Vaccine Against Challenge With H5N1 Clades 1.1.2 and 2.3.2.1 Highly Pathogenic Avian Influenza Viruses in Domestic Ducks (Anas platyrhynchos domesticus).

    Science.gov (United States)

    Pantin-Jackwood, Mary J; Kapczynski, Darrell R; DeJesus, Eric; Costa-Hurtado, Mar; Dauphin, Gwenaelle; Tripodi, Astrid; Dunn, John R; Swayne, David E

    2016-03-01

    Domestic ducks are the second most abundant poultry species in many Asian countries and have played a critical role in the epizootiology of H5N1 highly pathogenic avian influenza (HPAI).In this study, the protective efficacy of a live recombinant vector vaccine based on a turkey herpesvirus (HVT) expressing the H5 gene from a clade 2.2 H5N1 HPAI strain (A/Swan/Hungary/4999/ 2006) (rHVT-H5/2.2), given at 3 days of age, was examined in Pekin ducks (Anas platyrhynchos domesticus). The vaccine was given alone or in combination with an inactivated H5N1 clade 2.3.2.1 reverse genetic (rgGD/2.3.2.1) vaccine given at 16 days of age, either as a single vaccination or in a prime-boost regime. At 30 days of age, ducks were challenged with one of two H5N1 HPAI viruses: A/duck/Vietnam/NCVD-2721/2013 (clade 1.1.2) or A/duck/Vietnam/NCVD-1584/2012 (clade 2.3.2.1.C). These viruses produced 100% mortality in less than 5 days in nonvaccinated control ducks. Ducks vaccinated with the rgGD/2.3.2.1 vaccine, with or without the rHVT-H5/2.2 vaccine, were 90%-100% protected against mortality after challenge with either of the two H5N1 HPAI viruses. The rHVT-H5/2.2 vaccine alone, however, conferred only 30% protection against mortality after challenge with either H5N1 HPAI virus; the surviving ducks from these groups shed higher amount of virus and for longer than the single-vaccinated rgGD/2.3.2.1 group. Despite low protection, ducks vaccinated with the rHVT-H5/2.2 vaccine and challenged with the clade 1.1.2 Vietnam virus had a longer mean death time than nonvaccinated controls (P = 0.02). A booster effect was found on reduction of virus shedding when using both vaccines, with lower oropharyngeal viral titers at 4 days after challenge with either HPAI virus (P vaccine could be detected in samples collected from multiple tissues at different time points, indicting minimal levels of viral replication. In conclusion, although a minor effect on survival was observed, this study demonstrates

  16. 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

  17. 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.

  18. Intranasal H5N1 vaccines, adjuvanted with chitosan derivatives, protect ferrets against highly pathogenic influenza intranasal and intratracheal challenge

    NARCIS (Netherlands)

    A.J. Mann (Alex); N. Noulin (Nicolas); A. Catchpole (Andrew); K.J. Stittelaar (Koert); L. de Waal (Leon); E.J.B. Veldhuis Kroeze (Edwin); M. Hinchcliffe (Michael); A. Smith (Alan); E. Montomoli (Emanuele); S. Piccirella (Simona); A.D.M.E. Osterhaus (Albert); A. Knight (Alastair); J. Oxford; G. Lapini (Giulia); R. Cox (Ruben); R. Lambkin-Williams (Rob)

    2014-01-01

    textabstractWe investigated the protective efficacy of two intranasal chitosan (CSN and TM-CSN) adjuvanted H5N1 Influenza vaccines against highly pathogenic avian Influenza (HPAI) intratracheal and intranasal challenge in a ferret model. Six groups of 6 ferrets were intranasally vaccinated twice, 21

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

    Directory of Open Access Journals (Sweden)

    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

  20. 人感染高致病性禽流感病毒H5N1的病理学和病原学特点%Histologic and ultrastructural studies of the patient died of highly pathogenic H5N1 avian influenza virus infection in China

    Institute of Scientific and Technical Information of China (English)

    李宁; 祝庆余; 余琦; 王巍; 王一平

    2008-01-01

    Objective To explore histopathologic and ultrastructural characteristics of human avian influenza (AI) infection and related etiological pathogenesis.Methods Postmortem lung and heart samples were collected from the patient who died of avian influenza virus infection on November 29,2003 in China.Light and electron microscopy,immunohistochemistry and histochemistry were used to investigate the pathological changes.Results The main pathological findings included extensive pulmonary consolidation,hemorrhage,pulmonary edema and local hemorrhagic infarct.The lamina of alveoli and bronchioles were abundantly filled with protein-rich fluid,erythrocytes,fibrin and cell debris admixed with many neutrophilis.macrophages,lymphocytes and a few of monokaryon and multinuclear giant cells.Hyaline membranes were formed.Local pulmonary tissues were heavily damaged by hemorrhage and necrosis.Alveolar septum was disintegrated.Mesenchymal edema with a few of macrophages infiltration of heart was found.Electron microscopy showed the avian influenza A virus-like particles (type C and type A) of 80~120 nm diameter and envelopes in the cytoplasm of pneumocytes and endothelial cells.Conclusions Fatal pneumonia associated with highly pathogenic avian influenza A virus (H5N1) infection leads to extensive pulmonary consolidation,edema and marked hemorrhagic necrosis and inflammation.Electron microscopy can identify avian influenza A virus-like particles.The findings may offer an important theoretical basis for clinical diagnosis and treatment.%目的 探讨人感染禽流行性感冒病毒的病理学及病原学特点.方法 应用透射电镜、光镜、组织化学和免疫组织化学方法对发生在2003年11月中国内地人禽流感死亡尸检病例1例进行观察研究.行病原体分离培养鉴定、全基因组序列测定和动物致病性观察以确定病原学特点.结果 肺部病理改变主要表现为广泛性肺实变,肺出血、肺水肿及坏死.肺泡腔内充

  1. Discover binding pathways using the sliding binding-box docking approach: application to binding pathways of oseltamivir to avian influenza H5N1 neuraminidase

    Science.gov (United States)

    Tran, Diem-Trang T.; Le, Ly T.; Truong, Thanh N.

    2013-08-01

    Drug binding and unbinding are transient processes which are hardly observed by experiment and difficult to analyze by computational techniques. In this paper, we employed a cost-effective method called "pathway docking" in which molecular docking was used to screen ligand-receptor binding free energy surface to reveal possible paths of ligand approaching protein binding pocket. A case study was applied on oseltamivir, the key drug against influenza a virus. The equilibrium pathways identified by this method are found to be similar to those identified in prior studies using highly expensive computational approaches.

  2. 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.