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Sample records for drug-resistant avian h5n1

  1. Avian influenza A H5N1 virus.

    PubMed

    Loeffelholz, Michael J

    2010-03-01

    Although influenza A viruses of avian origin have long been responsible for influenza pandemics, including the "Spanish flu" pandemic of 1918, human infections caused by avian subtypes of influenza A virus, most notably H5N1, have emerged since the 1990s (H5N1 in 1997; H9N2 in 1999; and H7N7 in 2003). The wide geographic distribution of influenza A H5N1 in avian species, and the number and severity of human infections are unprecedented. Together with the ongoing genetic evolution of this virus, these features make influenza A H5N1 a likely candidate for a future influenza pandemic. This article discusses the epidemiology, pathogenesis, and diagnosis of human infections caused by influenza A H5N1 virus.

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

    PubMed

    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. Highly Pathogenic Avian Influenza H5N1, Thailand, 2004

    PubMed Central

    Chaitaweesub, Prasit; Songserm, Thaweesak; Chaisingh, Arunee; Hoonsuwan, Wirongrong; Buranathai, Chantanee; Parakamawongsa, Tippawon; Premashthira, Sith; Amonsin, Alongkorn; Gilbert, Marius; Nielen, Mirjam; Stegeman, Arjan

    2005-01-01

    In January 2004, highly pathogenic avian influenza (HPAI) virus of the H5N1 subtype was first confirmed in poultry and humans in Thailand. Control measures, e.g., culling poultry flocks, restricting poultry movement, and improving hygiene, were implemented. Poultry populations in 1,417 villages in 60 of 76 provinces were affected in 2004. A total of 83% of infected flocks confirmed by laboratories were backyard chickens (56%) or ducks (27%). Outbreaks were concentrated in the Central, the southern part of the Northern, and Eastern Regions of Thailand, which are wetlands, water reservoirs, and dense poultry areas. More than 62 million birds were either killed by HPAI viruses or culled. H5N1 virus from poultry caused 17 human cases and 12 deaths in Thailand; a number of domestic cats, captive tigers, and leopards also died of the H5N1 virus. In 2005, the epidemic is ongoing in Thailand. PMID:16318716

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

    PubMed

    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.

  5. Pathogenesis of H5N1 avian influenza virus reassortants in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic H5N1 avian influenza viruses produce severe disease and mortality in chickens. Identification of viral genes important for cell tropism and replication efficiency helps identify virulence factors. To determine which viral gene or genes contribute to the virulence of H5N1 avian in...

  6. Recombinant Parainfluenza Virus 5 Expressing Hemagglutinin of Influenza A Virus H5N1 Protected Mice against Lethal Highly Pathogenic Avian Influenza Virus H5N1 Challenge

    PubMed Central

    Li, Zhuo; Mooney, Alaina J.; Gabbard, Jon D.; Gao, Xiudan; Xu, Pei; Place, Ryan J.; Hogan, Robert J.; Tompkins, S. Mark

    2013-01-01

    A safe and effective vaccine is the best way to prevent large-scale highly pathogenic avian influenza virus (HPAI) H5N1 outbreaks in the human population. The current FDA-approved H5N1 vaccine has serious limitations. A more efficacious H5N1 vaccine is urgently needed. Parainfluenza virus 5 (PIV5), a paramyxovirus, is not known to cause any illness in humans. PIV5 is an attractive vaccine vector. In our studies, a single dose of a live recombinant PIV5 expressing a hemagglutinin (HA) gene of H5N1 (rPIV5-H5) from the H5N1 subtype provided sterilizing immunity against lethal doses of HPAI H5N1 infection in mice. Furthermore, we have examined the effect of insertion of H5N1 HA at different locations within the PIV5 genome on the efficacy of a PIV5-based vaccine. Interestingly, insertion of H5N1 HA between the leader sequence, the de facto promoter of PIV5, and the first viral gene, nucleoprotein (NP), did not lead to a viable virus. Insertion of H5N1 HA between NP and the next gene, V/phosphorprotein (V/P), led to a virus that was defective in growth. We have found that insertion of H5N1 HA at the junction between the small hydrophobic (SH) gene and the hemagglutinin-neuraminidase (HN) gene gave the best immunity against HPAI H5N1 challenge: a dose as low as 1,000 PFU was sufficient to protect against lethal HPAI H5N1 challenge in mice. The work suggests that recombinant PIV5 expressing H5N1 HA has great potential as an HPAI H5N1 vaccine. PMID:23077314

  7. Determinants of pathogenicity of H5N1 highly pathogenic avian influenza viruses in ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ducks have been implicated in the dissemination and evolution of the H5N1 highly pathogenic avian influenza (HPAI) viruses. The pathogenicity of H5N1 HPAI viruses in domestic ducks has increased over time with some viruses producing 100% mortality in very short time. The determinants of pathogenic...

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

    PubMed

    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.

  9. Airborne transmission of H5N1 high pathogenicity avian influenza viruses during simulated home slaughter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most H5N1 human infections have occurred following exposure to H5N1 high pathogenicity avian influenza (HPAI) virus-infected poultry, especially when poultry are home slaughtered or slaughtered in live poultry markets. Previous studies have demonstrated that slaughter of clade 1 isolate A/Vietnam/1...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 pathogenic H5N1 AI viruses between 2004 and 2006. The hemagglutinin (HA) and neuraminidase (NA) genes from all 6 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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)...

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

    PubMed

    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.

  13. Detection prevalence of H5N1 avian influenza virus among stray cats in eastern China.

    PubMed

    Zhao, Fu-Rong; Zhou, Dong-Hui; Zhang, Yong-Guang; Shao, Jun-Jun; Lin, Tong; Li, Yang-Fan; Wei, Ping; Chang, Hui-Yun

    2015-08-01

    Since 1997, more and more cases of the infectious H5N1 avian influenza virus (AIV) in humans have been reported all over the world but the transmission of H5N1 avian influenza virus to stray cats has been little demonstrated. The objective of this pilot investigation was to determine the prevalence of H5N1 AIV antibodies in stray cats in eastern China where is the dominant enzootic H5N1 highly pathogenic avian influenza virus (HP AIV). A total of 1,020 nasal swab and 1,020 serum samples were collected and tested. Evidence of HPAI H5N1 virus antibodies was present in two of the 1,020 serum samples that were positive by HI assay and NT assay, respectively. The results imply little transmission and that the Clade 2.3.2 HPAIV H5N1 infections in poultry did not significantly affect the rural animal shelters or suburban environment in eastern China. In future studies, these results can be used as baseline seroepidemiological levels for H5N1 AIV among cats in China.

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

    PubMed

    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.

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

    PubMed Central

    Kaplan, Bryan S.; Webby, Richard J.

    2013-01-01

    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. PMID:24025480

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

    PubMed

    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.

  17. Avian Influenza A(H5N1) Virus in Egypt

    PubMed Central

    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.

    2016-01-01

    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. PMID:26886164

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

    PubMed

    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.

  19. Avian influenza virus (H5N1): a threat to human health.

    PubMed

    Peiris, J S Malik; de Jong, Menno D; Guan, Yi

    2007-04-01

    Pandemic influenza virus has its origins in avian influenza viruses. The highly pathogenic avian influenza virus subtype H5N1 is already panzootic in poultry, with attendant economic consequences. It continues to cross species barriers to infect humans and other mammals, often with fatal outcomes. Therefore, H5N1 virus has rightly received attention as a potential pandemic threat. However, it is noted that the pandemics of 1957 and 1968 did not arise from highly pathogenic influenza viruses, and the next pandemic may well arise from a low-pathogenicity virus. The rationale for particular concern about an H5N1 pandemic is not its inevitability but its potential severity. An H5N1 pandemic is an event of low probability but one of high human health impact and poses a predicament for public health. Here, we review the ecology and evolution of highly pathogenic avian influenza H5N1 viruses, assess the pandemic risk, and address aspects of human H5N1 disease in relation to its epidemiology, clinical presentation, pathogenesis, diagnosis, and management.

  20. Avian Influenza Virus (H5N1): a Threat to Human Health

    PubMed Central

    Peiris, J. S. Malik; de Jong, Menno D.; Guan, Yi

    2007-01-01

    Pandemic influenza virus has its origins in avian influenza viruses. The highly pathogenic avian influenza virus subtype H5N1 is already panzootic in poultry, with attendant economic consequences. It continues to cross species barriers to infect humans and other mammals, often with fatal outcomes. Therefore, H5N1 virus has rightly received attention as a potential pandemic threat. However, it is noted that the pandemics of 1957 and 1968 did not arise from highly pathogenic influenza viruses, and the next pandemic may well arise from a low-pathogenicity virus. The rationale for particular concern about an H5N1 pandemic is not its inevitability but its potential severity. An H5N1 pandemic is an event of low probability but one of high human health impact and poses a predicament for public health. Here, we review the ecology and evolution of highly pathogenic avian influenza H5N1 viruses, assess the pandemic risk, and address aspects of human H5N1 disease in relation to its epidemiology, clinical presentation, pathogenesis, diagnosis, and management. PMID:17428885

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  3. Viremia associated with fatal outcomes in ferrets infected with avian H5N1 influenza virus.

    PubMed

    Wang, Xue; Zhao, Jiangqin; Tang, Shixing; Ye, Zhiping; Hewlett, Indira

    2010-08-12

    Avian H5N1 influenza viruses cause severe disease and high mortality in infected humans. However, tissue tropism and underlying pathogenesis of H5N1 virus infection in humans needs further investigation. The objective of this work was to study viremia, tissue tropism and disease pathogenesis of H5N1 virus infection in the susceptible ferret animal model. To evaluate the relationship of morbidity and mortality with virus loads, we performed studies in ferrets infected with the H5N1 strain A/VN/1203/04 to assess clinical signs after infection and virus load in lung, brain, ileum, nasal turbinate, nasal wash, and blood. We observed that H5N1 infection in ferrets is characterized by high virus load in the brain and and low levels in the ileum using real-time PCR. In addition, viral RNA was frequently detected in blood one or two days before death and associated with symptoms of diarrhea. Our observations further substantiate pathogenicity of H5N1 and further indicate that viremia may be a bio-marker for fatal outcomes in H5N1 infection.

  4. Phage Displayed Peptides to Avian H5N1 Virus Distinguished the Virus from Other Viruses

    PubMed Central

    Qin, Chengfeng; Ren, Xiaofeng

    2011-01-01

    The purpose of the current study was to identify potential ligands and develop a novel diagnostic test to highly pathogenic avian influenza A virus (HPAI), subtype H5N1 viruses using phage display technology. The H5N1 viruses were used as an immobilized target in a biopanning process using a 12-mer phage display random peptide library. After five rounds of panning, three phages expressing peptides HAWDPIPARDPF, AAWHLIVALAPN or ATSHLHVRLPSK had a specific binding activity to H5N1 viruses were isolated. Putative binding motifs to H5N1 viruses were identified by DNA sequencing. In terms of the minimum quantity of viruses, the phage-based ELISA was better than antiserum-based ELISA and a manual, semi-quantitative endpoint RT-PCR for detecting H5N1 viruses. More importantly, the selected phages bearing the specific peptides to H5N1 viruses were capable of differentiating this virus from other avian viruses in enzyme-linked immunosorbent assays. PMID:21887228

  5. An H5N1 highly pathogenic avian influenza virus that invaded Japan through waterfowl migration.

    PubMed

    Kajihara, Masahiro; Matsuno, Keita; Simulundu, Edgar; Muramatsu, Mieko; Noyori, Osamu; Manzoor, Rashid; Nakayama, Eri; Igarashi, Manabu; Tomabechi, Daisuke; Yoshida, Reiko; Okamatsu, Masatoshi; Sakoda, Yoshihiro; Ito, Kimihito; Kida, Hiroshi; Takada, Ayato

    2011-08-01

    In 2010, an H5N1 highly pathogenic avian influenza virus (HPAIV) was isolated from feces of apparently healthy ducks migrating southward in Hokkaido, the northernmost prefecture of Japan. The H5N1 HPAIVs were subsequently detected in domestic and wild birds at multiple sites corresponding to the flyway of the waterfowl having stopovers in the Japanese archipelago. The Hokkaido isolate was genetically nearly identical to H5N1 HPAIVs isolated from swans in the spring of 2009 and 2010 in Mongolia, but less pathogenic in experimentally infected ducks than the 2009 Mongolian isolate. These findings suggest that H5N1 HPAIVs with relatively mild pathogenicity might be selected and harbored in the waterfowl population during the 2009-2010 migration seasons. Our data provide "early warning" signals for preparedness against the unprecedented situation in which the waterfowl reservoirs serve as perpetual sources and disseminators of HPAIVs.

  6. Evolution of highly pathogenic avian H5N1 influenza viruses

    SciTech Connect

    Macken, Catherine A; Green, Margaret A

    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 avian H5N1 viruses.

  7. Pathogenicity, Transmission and Antigenic Variation of H5N1 Highly Pathogenic Avian Influenza Viruses.

    PubMed

    Jiao, Peirong; Song, Hui; Liu, Xiaoke; Song, Yafen; Cui, Jin; Wu, Siyu; Ye, Jiaqi; Qu, Nanan; Zhang, Tiemin; Liao, Ming

    2016-01-01

    H5N1 highly pathogenic avian influenza (HPAI) was one of the most important avian diseases in poultry production of China, especially in Guangdong province. In recent years, new H5N1 highly pathogenic avian influenza viruses (HPAIV) still emerged constantly, although all poultry in China were immunized with H5N1 vaccinations compulsorily. To better understand the pathogenicity and transmission of dominant clades of the H5N1 HPAIVs in chicken from Guangdong in 2012, we chose a clade 7.2 avian influenza virus named A/Chicken/China/G2/2012(H5N1) (G2) and a clade 2.3.2.1 avian influenza virus named A/Duck/China/G3/2012(H5N1) (G3) in our study. Our results showed that the chickens inoculated with 10(3) EID50 of G2 or G3 viruses all died, and the titers of virus replication detected in several visceral organs were high but different. In the naive contact groups, virus shedding was not detected in G2 group and all chickens survived, but virus shedding was detected in G3 group and all chickens died. These results showed that the two clades of H5N1 HPAIVs had high pathogenicity in chickens and the contact transmission of them was different in chickens. The results of cross reactive HI assay showed that antigens of G2 and G3 were very different from those of current commercial vaccines isolates (Re-4, Re-6, and D7). And to evaluate the protective efficacy of three vaccines against most isolates form Guangdong belonging to clade 2.3.2.1 in 2012, G3 was chosen to challenge the three vaccines such as Re-4, Re-6, and D7. First, chickens were immunized with 0.3 ml Re-4, Re-6, and D7 inactivated vaccines by intramuscular injection, respectively, and then challenged with 10(6) EID50 of G3 on day 28 post-vaccination. The D7 vaccine had 100% protection against G3 for chickens, the Re-6 vaccine had 88.9%, and the Re-4 vaccine only had 66.7%. Our results suggested that the D7 vaccine could prevent and control H5N1 virus outbreaks more effectively in Guangdong. From the above, it was

  8. Pathogenicity, Transmission and Antigenic Variation of H5N1 Highly Pathogenic Avian Influenza Viruses

    PubMed Central

    Jiao, Peirong; Song, Hui; Liu, Xiaoke; Song, Yafen; Cui, Jin; Wu, Siyu; Ye, Jiaqi; Qu, Nanan; Zhang, Tiemin; Liao, Ming

    2016-01-01

    H5N1 highly pathogenic avian influenza (HPAI) was one of the most important avian diseases in poultry production of China, especially in Guangdong province. In recent years, new H5N1 highly pathogenic avian influenza viruses (HPAIV) still emerged constantly, although all poultry in China were immunized with H5N1 vaccinations compulsorily. To better understand the pathogenicity and transmission of dominant clades of the H5N1 HPAIVs in chicken from Guangdong in 2012, we chose a clade 7.2 avian influenza virus named A/Chicken/China/G2/2012(H5N1) (G2) and a clade 2.3.2.1 avian influenza virus named A/Duck/China/G3/2012(H5N1) (G3) in our study. Our results showed that the chickens inoculated with 103 EID50 of G2 or G3 viruses all died, and the titers of virus replication detected in several visceral organs were high but different. In the naive contact groups, virus shedding was not detected in G2 group and all chickens survived, but virus shedding was detected in G3 group and all chickens died. These results showed that the two clades of H5N1 HPAIVs had high pathogenicity in chickens and the contact transmission of them was different in chickens. The results of cross reactive HI assay showed that antigens of G2 and G3 were very different from those of current commercial vaccines isolates (Re-4, Re-6, and D7). And to evaluate the protective efficacy of three vaccines against most isolates form Guangdong belonging to clade 2.3.2.1 in 2012, G3 was chosen to challenge the three vaccines such as Re-4, Re-6, and D7. First, chickens were immunized with 0.3 ml Re-4, Re-6, and D7 inactivated vaccines by intramuscular injection, respectively, and then challenged with 106 EID50 of G3 on day 28 post-vaccination. The D7 vaccine had 100% protection against G3 for chickens, the Re-6 vaccine had 88.9%, and the Re-4 vaccine only had 66.7%. Our results suggested that the D7 vaccine could prevent and control H5N1 virus outbreaks more effectively in Guangdong. From the above, it was

  9. Characterization of highly pathogenic H5N1 avian influenza A viruses isolated from South Korea.

    PubMed

    Lee, Chang-Won; Suarez, David L; Tumpey, Terrence M; Sung, Haan-Woo; Kwon, Yong-Kuk; Lee, Youn-Jeong; Choi, Jun-Gu; Joh, Seong-Joon; Kim, Min-Chul; Lee, Eun-Kyoung; Park, Jong-Myung; Lu, Xiuhua; Katz, Jacqueline M; Spackman, Erica; Swayne, David E; Kim, Jae-Hong

    2005-03-01

    An unprecedented outbreak of H5N1 highly pathogenic avian influenza (HPAI) has been reported for poultry in eight different Asian countries, including South Korea, since December 2003. A phylogenetic analysis of the eight viral genes showed that the H5N1 poultry isolates from South Korea were of avian origin and contained the hemagglutinin and neuraminidase genes of the A/goose/Guangdong/1/96 (Gs/Gd) lineage. The current H5N1 strains in Asia, including the Korean isolates, share a gene constellation similar to that of the Penfold Park, Hong Kong, isolates from late 2002 and contain some molecular markers that seem to have been fixed in the Gs/Gd lineage virus since 2001. However, despite genetic similarities among recent H5N1 isolates, the topology of the phylogenetic tree clearly differentiates the Korean isolates from the Vietnamese and Thai isolates which have been reported to infect humans. A representative Korean isolate was inoculated into mice, with no mortality and no virus being isolated from the brain, although high titers of virus were observed in the lungs. The same isolate, however, caused systemic infections in chickens and quail and killed all of the birds within 2 and 4 days of intranasal inoculation, respectively. This isolate also replicated in multiple organs and tissues of ducks and caused some mortality. However, lower virus titers were observed in all corresponding tissues of ducks than in chicken and quail tissues, and the histological lesions were restricted to the respiratory tract. This study characterizes the molecular and biological properties of the H5N1 HPAI viruses from South Korea and emphasizes the need for comparative analyses of the H5N1 isolates from different countries to help elucidate the risk of a human pandemic from the strains of H5N1 HPAI currently circulating in Asia.

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

    PubMed

    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. Yeast Surface-Displayed H5N1 Avian Influenza Vaccines

    PubMed Central

    Lei, Han; Jin, Sha; Karlsson, Erik; Schultz-Cherry, Stacey

    2016-01-01

    Highly pathogenic H5N1 avian influenza viruses pose a pandemic threat to human health. A rapid vaccine production against fast outbreak is desired. We report, herein, a paradigm-shift influenza vaccine technology by presenting H5N1 hemagglutinin (HA) to the surface of yeast. We demonstrated, for the first time, that the HA surface-presented yeast can be used as influenza vaccines to elicit both humoral and cell-mediated immunity in mice. The HI titer of antisera reached up to 128 in vaccinated mice. A high level of H5N1 HA-specific IgG1 and IgG2a antibody production was detected after boost immunization. Furthermore, we demonstrated that the yeast surface-displayed HA preserves its antigenic sites. It preferentially binds to both avian- and human-type receptors. In addition, the vaccine exhibited high cross-reactivity to both homologous and heterologous H5N1 viruses. A high level production of anti-HA antibodies was detected in the mice five months after vaccination. Finally, our animal experimental results indicated that the yeast vaccine offered complete protection of mice from lethal H5N1 virus challenge. No severe side effect of yeast vaccines was noted in animal studies. This new technology allows for rapid and large-scale production of influenza vaccines for prepandemic preparation. PMID:28078309

  12. Yeast Surface-Displayed H5N1 Avian Influenza Vaccines.

    PubMed

    Lei, Han; Jin, Sha; Karlsson, Erik; Schultz-Cherry, Stacey; Ye, Kaiming

    2016-01-01

    Highly pathogenic H5N1 avian influenza viruses pose a pandemic threat to human health. A rapid vaccine production against fast outbreak is desired. We report, herein, a paradigm-shift influenza vaccine technology by presenting H5N1 hemagglutinin (HA) to the surface of yeast. We demonstrated, for the first time, that the HA surface-presented yeast can be used as influenza vaccines to elicit both humoral and cell-mediated immunity in mice. The HI titer of antisera reached up to 128 in vaccinated mice. A high level of H5N1 HA-specific IgG1 and IgG2a antibody production was detected after boost immunization. Furthermore, we demonstrated that the yeast surface-displayed HA preserves its antigenic sites. It preferentially binds to both avian- and human-type receptors. In addition, the vaccine exhibited high cross-reactivity to both homologous and heterologous H5N1 viruses. A high level production of anti-HA antibodies was detected in the mice five months after vaccination. Finally, our animal experimental results indicated that the yeast vaccine offered complete protection of mice from lethal H5N1 virus challenge. No severe side effect of yeast vaccines was noted in animal studies. This new technology allows for rapid and large-scale production of influenza vaccines for prepandemic preparation.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  14. Studies on H5N1 avian influenza virus gene reassortants in vivo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to determine which viral gene or genes contribute to the virulence of H5N1 avian influenza viruses in chickens, we used reverse genetics to generate single-gene recombinant viruses and examined their pathogenicity in chickens. Intranasal inoculation of two week-old chickens with the recomb...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. Chlorine inactivation of H5N1 highly pathogenic avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two Asian strains of H5N1 highly pathogenic avian influenza virus were studied to determine their resistance to chlorination. Experiments were conducted at two pH levels (pH 7 and 8) at 5 C. CT (chlorine concentration x exposure time) values were calculated for different levels of inactivation. R...

  17. Highly pathogenic avian influenza (H5N1) outbreaks in wild birds and poultry, South Korea.

    PubMed

    Kim, Hye-Ryoung; Lee, Youn-Jeong; Park, Choi-Kyu; Oem, Jae-Ku; Lee, O-Soo; Kang, Hyun-Mi; Choi, Jun-Gu; Bae, You-Chan

    2012-03-01

    Highly pathogenic avian influenza (H5N1) among wild birds emerged simultaneously with outbreaks in domestic poultry in South Korea during November 2010-May 2011. Phylogenetic analysis showed that these viruses belonged to clade 2.3.2, as did viruses found in Mongolia, the People's Republic of China, and Russia in 2009 and 2010.

  18. Changing pathobiology of H5N1 highly pathogenic avian influenza (HPAI) viruses in domestic waterfowl

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Eurasian-African lineage of H5N1 highly pathogenic avian influenza (HPAI) viruses has evolved into many genetic lineages and multiple sublineages. The divergent strains that have arisen express distinct pathobiological features and increased virulence for many bird species including domestic wa...

  19. Knowledge, attitudes, and practices regarding avian influenza (H5N1), Afghanistan.

    PubMed

    Leslie, Toby; Billaud, Julie; Mofleh, Jawad; Mustafa, Lais; Yingst, Sam

    2008-09-01

    From February through April 2007, avian influenza (H5N1) was confirmed in poultry in 4 of 34 Afghan provinces. A survey conducted in 2 affected and 3 unaffected provinces found that greater knowledge about reducing exposure was associated with higher socioeconomic status, residence in affected provinces, and not owning backyard poultry.

  20. Highly Pathogenic Avian Influenza H5N1 in Mainland China.

    PubMed

    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.

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

    PubMed

    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.

  2. Highly Pathogenic Avian Influenza H5N1 in Mainland China

    PubMed Central

    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

    2015-01-01

    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

  3. 2.1 Natural History of Highly Pathogenic Avian Influenza H5N1

    PubMed Central

    Sonnberg, Stephanie; Webby, Richard J.; Webster, Robert G.

    2013-01-01

    The ecology of highly pathogenic avian influenza (HPAI) H5N1 has significantly changed from sporadic outbreaks in terrestrial poultry to persistent circulation in terrestrial and aquatic poultry and potentially in wild waterfowl. A novel genotype of HPAI H5N1 arose in 1996 in southern China and through ongoing mutation, reassortment, and natural selection, has diverged into distinct lineages and expanded into multiple reservoir hosts. The evolution of Goose/Guangdong-lineage highly pathogenic H5N1 viruses is ongoing: while stable interactions exist with some reservoir hosts, these viruses are continuing to evolve and adapt to others, and pose an un-calculable risk to sporadic hosts, including humans. PMID:23735535

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

    PubMed

    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.

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

    PubMed Central

    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 (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. PMID:23112728

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

    PubMed

    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 (<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.

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

    USGS Publications Warehouse

    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.

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

    PubMed Central

    Tian, Huaiyu; 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. PMID:25535385

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

    PubMed

    Tian, Huaiyu; 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

    2015-01-06

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

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

    PubMed

    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

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

    USGS Publications Warehouse

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

    USGS Publications Warehouse

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

    2007-01-01

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

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

    PubMed Central

    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. PMID:26900963

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

    PubMed

    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.

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

    PubMed

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

    2016-01-01

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

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

    PubMed

    Stewart, Cameron R; Karpala, Adam J; Lowther, Sue; Lowenthal, John W; Bean, Andrew G

    2011-01-01

    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 (si)RNAs 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.

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

    PubMed

    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.

  18. Circulation of avian influenza H5N1 in live bird markets in Egypt.

    PubMed

    Abdelwhab, E M; Selim, A A; Arafa, A; Galal, S; Kilany, W H; Hassan, M K; Aly, M M; Hafez, M H

    2010-06-01

    The poultry meat trade in Egypt depends mainly on live bird markets (LBMs) because of insufficient slaughterhouses, lack of marketing infrastructure, and cultural preference for consumption of freshly slaughtered poultry. There are two types of LBMs in Egypt: retail shops and traditional LBMs where minimal, if any, food safety standards or veterinary inspection are implemented. Before January 2009, LBMs were considered to be a missing link in the epidemiology of avian influenza in Egypt. This incited us to initiate this surveillance to better understand the perpetuation of H5N1 and the risk of infection in poultry markets. Seventy-one out of 573 (12.4%) examined LBMs were positive for the H5N1 subtype by real-time--quantitative polymerase chain reaction (RT-qPCR) from January to April 2009. Where a 70.4% detection rate from LBMs had waterfowl only as a solitary sold species, a 26.8% detection rate from LBMs had waterfowl mixed with chicken and/or turkey, and 2.8% from LBMs had only turkey. Higher incidence, 40.8%, of positive LBMs was recorded during the cold month of February and concentrated mainly in the highly populated Nile Delta. These findings revealed wide circulation of H5N1 avian influenza virus in LBMs in Egypt, which poses a threat to public health and the poultry industry. Long-term control measures are required, and routine surveillance of bird markets should be conducted year-round.

  19. Subclinical Infection with Avian Influenza A H5N1 Virus in Cats

    PubMed Central

    Weikel, Joachim; Möstl, Karin; Revilla-Fernández, Sandra; Wodak, Eveline; Bagó, Zoltan; Vanek, Elisabeth; Benetka, Viviane; Hess, Michael; Thalhammer, Johann G.

    2007-01-01

    Avian influenza A virus subtype H5N1 was transmitted to domestic cats by close contact with infected birds. Virus-specific nucleic acids were detected in pharyngeal swabs from 3 of 40 randomly sampled cats from a group of 194 animals (day 8 after contact with an infected swan). All cats were transferred to a quarantine station and monitored for clinical signs, virus shedding, and antibody production until day 50. Despite unfamiliar handling, social distress and the presence of other viral and nonviral pathogens that caused illness and poor health and compromised the immune systems, none of the cats developed clinical signs of influenza. There was no evidence of horizontal transmission to other cats because only 2 cats developed antibodies against H5N1 virus. PMID:17479886

  20. The threat of avian influenza A (H5N1). Part III: Antiviral therapy.

    PubMed

    Cinatl, Jindrich; Michaelis, Martin; Doerr, Hans W

    2007-12-01

    Among emerging and re-emerging infectious diseases, influenza constitutes one of the major threats to mankind. In this review series epidemiologic, virologic and pathologic concerns raised by infections of humans with avian influenza virus A/H5N1 as well as treatment options are discussed. The third part discusses therapeutic options. Neuraminidase (NA) inhibitors are the most promising agents despite uncertainty about efficacy. Dosage increase, prolonged treatment or combination therapies may increase treatment efficacy and/or inhibit resistance formation. Immune system dysregulation contributes to H5N1 disease. Although current evidence does not support the use of anti-inflammatory drugs beneficial effects cannot be excluded at later disease stages.

  1. Amantadine resistance among highly pathogenic avian influenza viruses (H5N1) isolated from India.

    PubMed

    Jacob, Aron; Sood, Richa; Chanu, Kh Victoria; Bhatia, Sandeep; Khandia, Rekha; Pateriya, A K; Nagarajan, S; Dimri, U; Kulkarni, D D

    2016-02-01

    Emergence of antiviral resistance among H5N1 avian influenza viruses is the major challenge in the control of pandemic influenza. Matrix 2 (M2) inhibitors (amantadine and rimantadine) and neuraminidase inhibitors (oseltamivir and zanamivir) are the two classes of antiviral agents that are specifically active against influenza viruses and are used for both treatment and prophylaxis of influenza infections. Amantadine targets the M2 ion channel of influenza A virus and interrupts virus life cycle through blockade of hydrogen ion influx. This prevents uncoating of the virus in infected host cells which impedes the release of ribonucleoprotein required for transcription and replication of virion in the nucleus. The present study was carried out to review the status of amantadine resistance in H5N1 viruses isolated from India and to study their replicative capability. Results of the study revealed resistance to amantadine in antiviral assay among four H5N1 viruses out of which two viruses had Serine 31 Asparagine (AGT-AAT i.e., S31N) mutation and two had Valine 27 Alanine (GTT-GCT i.e., V27A) mutation. The four resistant viruses not only exhibited significant difference in effective concentration 50% (EC50) values of amantadine hydrochloride from that of susceptible viruses (P < 0.0001) but also showed significant difference between two different types (S31N and V27A) of mutant viruses (P < 0.05). Resistance to amantadine could also be demonstrated in a simple HA test after replication of the viruses in MDCK cells in presence of amantadine. The study identifies the correlation between in vitro antiviral assay and presence of established molecular markers of resistance, the retention of replicative capacity in the presence of amantadine hydrochloride by the resistant viruses and the emergence of resistant mutations against amantadine among avian influenza viruses (H5N1) without selective drug pressure.

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

    PubMed

    Shahid, Muhammad Akbar; Abubakar, Muhammad; Hameed, Sajid; Hassan, Shamsul

    2009-03-28

    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 10(8.3) ELD(50)/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 degrees C, after 1 day at 28 degrees C but remained viable for more than 100 days at 4 degrees 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.

  3. Ecological Determinants of Highly Pathogenic Avian Influenza (H5N1) Outbreaks in Bangladesh

    PubMed Central

    Ahmed, Syed S. U.; Ersbøll, Annette K.; Biswas, Paritosh K.; Christensen, Jens P.; Hannan, Abu S. M. A.; Toft, Nils

    2012-01-01

    Background The agro-ecology and poultry husbandry of the south Asian and south-east Asian countries share common features, however, with noticeable differences. Hence, the ecological determinants associated with risk of highly pathogenic avian influenza (HPAI-H5N1) outbreaks are expected to differ 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 approaches for unmeasured spatially correlated variation. Methodology/Principal Findings An ecological study at subdistrict level in Bangladesh was performed with 138 subdistricts with HPAI-H5N1 outbreaks during 2007–2008, and 326 subdistricts with no outbreaks. The association between ecological determinants and HPAI-H5N1 outbreaks was examined using a generalized linear mixed model. Spatial clustering of the ecological data was modeled using 1) an intrinsic conditional autoregressive (ICAR) model at subdistrict level considering their first order neighbors, and 2) a multilevel (ML) model with subdistricts nested within districts. Ecological determinants significantly associated with risk of HPAI-H5N1 outbreaks at subdistrict level were migratory birds' staging areas, river network, household density, literacy rate, poultry density, live bird markets, and highway network. Predictive risk maps were derived based on the resulting models. The resulting models indicate that the ML model absorbed some of the covariate effect of the ICAR model because of the neighbor structure implied in the two different models. Conclusions/Significance The study identified a new set of ecological determinants related to river networks, migratory birds' staging areas and literacy rate in addition to already known risk factors, and clarified that the generalized concept of free grazing duck and

  4. Avian influenza A H5N1 virus: a continuous threat to humans

    PubMed Central

    To, Kelvin KW; Ng, Kenneth HL; Que, Tak-Lun; Chan, Jacky MC; Tsang, Kay-Yan; Tsang, Alan KL; Chen, Honglin; Yuen, Kwok-Yung

    2012-01-01

    We report the first case of severe pneumonia due to co-infection with the emerging avian influenza A (H5N1) virus subclade 2.3.2.1 and Mycoplasma pneumoniae. The patient was a returning traveller who had visited a poultry market in South China. We then review the epidemiology, virology, interspecies barrier limiting poultry-to-human transmission, clinical manifestation, laboratory diagnosis, treatment and control measures of H5N1 clades that can be transmitted to humans. The recent controversy regarding the experiments involving aerosol transmission of recombinant H5N1 virus between ferrets is discussed. We also review the relative contribution of the poor response to antiviral treatment and the virus-induced hyperinflammatory damage to the pathogenesis and the high mortality of this infection. The factors related to the host, virus or medical intervention leading to the difference in disease mortality of different countries remain unknown. Because most developing countries have difficulty in instituting effective biosecurity measures, poultry vaccination becomes an important control measure. The rapid evolution of the virus would adversely affect the efficacy of poultry vaccination unless a correctly matched vaccine was chosen, manufactured and administered in a timely manner. Vigilant surveillance must continue to allow better preparedness for another poultry or human pandemic due to new viral mutants. PMID:26038430

  5. Predicting the global spread of H5N1 avian influenza

    PubMed Central

    Kilpatrick, A. Marm; Chmura, Aleksei A.; Gibbons, David W.; Fleischer, Robert C.; Marra, Peter P.; Daszak, Peter

    2006-01-01

    The spread of highly pathogenic H5N1 avian influenza into Asia, Europe, and Africa has resulted in enormous impacts on the poultry industry and presents an important threat to human health. The pathways by which the virus has and will spread between countries have been debated extensively, but have yet to be analyzed comprehensively and quantitatively. We integrated data on phylogenetic relationships of virus isolates, migratory bird movements, and trade in poultry and wild birds to determine the pathway for 52 individual introduction events into countries and predict future spread. We show that 9 of 21 of H5N1 introductions to countries in Asia were most likely through poultry, and 3 of 21 were most likely through migrating birds. In contrast, spread to most (20/23) countries in Europe was most likely through migratory birds. Spread in Africa was likely partly by poultry (2/8 introductions) and partly by migrating birds (3/8). Our analyses predict that H5N1 is more likely to be introduced into the Western Hemisphere through infected poultry and into the mainland United States by subsequent movement of migrating birds from neighboring countries, rather than from eastern Siberia. These results highlight the potential synergism between trade and wild animal movement in the emergence and pandemic spread of pathogens and demonstrate the value of predictive models for disease control. PMID:17158217

  6. Immunogenicity of avian H5N1 influenza virus recombinant vaccines in cats.

    PubMed

    Uhl, Elizabeth W; Harvey, Stephen B; Michel, Frank; Perozo, Yaneth; Gabbard, Jon; Tompkins, S Mark; Hogan, Robert J

    2010-04-01

    Confirmed reports of large domesticated cats becoming infected with highly pathogenic avian influenza (HPAI) H5N1 virus have raised questions about both the risk of infection for these animals, and their potential as vector or reservoir hosts in an influenza pandemic. With this in mind, we examined the immunogenicity of the hemagglutinin (HA) of H5N1 strain A/Vietnam/1203/04 using several different vaccination strategies. Data from ELISA assays showed that vaccination with a single dose of recombinant H5 HA protein induces a robust antibody response against both whole inactivated virus and recombinant HA antigen. Moreover, a single dose of the recombinant H5 HA protein induced hemagglutination inhibition titers >or=40, which is indicative of protective immunization. Cats receiving the IND H5N1 vaccine required two doses before similar H5 HA-specific antibody titers were observed, and despite boosting, these animals had HIA titers that were lower than or equivalent to those in the group receiving one injection of recombinant protein. In contrast, cats vaccinated with plasmid DNA encoding HA failed to develop HA-specific antibody responses above those seen in cohorts receiving an unrelated control plasmid. The results of this study indicate that recombinant H5 HA protein-based vaccines can rapidly induce high serum antibody titers, and may be more effective than either inactivated influenza virus or DNA vaccines in cats.

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

    PubMed

    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.

  8. Genetic characterization and phylogenic analysis of H5N1 avian influenza virus detected in peafowl in Kirkuk province, Iraq.

    PubMed

    Rashid, Peshnyar M A; Saeed, Nahla M; Dyary, Hiewa Othman

    2016-12-30

    A highly pathogenic avian influenza (HPAI), H5N1, was detected for the first time in peafowls in Kirkuk province, Iraq in 2015. Genetic analysis of the Kirkuk H5N1 indicated molecular markers for avian-type receptors. The Kirkuk H5N1 hemagglutinin gene had an infrequent amino acid cleavage site (SPQREKRRKRGLF), and neuraminidase genes showed sensitive molecular markers for antiviral drugs. Additionally, the phylogenetic analysis found that the Kirkuk H5N1 belonged to subclade 2.3.2.1c. Our results showed that the 2015 H5N1 from the Iraqi city of Kirkuk exhibited new genetic characterization and was different from the 2006 H5N1 isolate from Iraq.

  9. Highly pathogenic avian influenza H5N1 virus delays apoptotic responses via activation of STAT3.

    PubMed

    Hui, Kenrie P Y; Li, Hung Sing; Cheung, Man Chun; Chan, Renee W Y; Yuen, Kit M; Mok, Chris K P; Nicholls, John M; Peiris, J S Malik; Chan, Michael C W

    2016-06-27

    Highly pathogenic avian influenza (HPAI) H5N1 virus continues to pose pandemic threat, but there is a lack of understanding of its pathogenesis. We compared the apoptotic responses triggered by HPAI H5N1 and low pathogenic H1N1 viruses using physiologically relevant respiratory epithelial cells. We demonstrated that H5N1 viruses delayed apoptosis in primary human bronchial and alveolar epithelial cells (AECs) compared to H1N1 virus. Both caspase-8 and -9 were activated by H5N1 and H1N1 viruses in AECs, while H5N1 differentially up-regulated TRAIL. H5N1-induced apoptosis was reduced by TRAIL receptor silencing. More importantly, STAT3 knock-down increased apoptosis by H5N1 infection suggesting that H5N1 virus delays apoptosis through activation of STAT3. Taken together, we demonstrate that STAT3 is involved in H5N1-delayed apoptosis compared to H1N1. Since delay in apoptosis prolongs the duration of virus replication and production of pro-inflammatory cytokines and TRAIL from H5N1-infected cells, which contribute to orchestrate cytokine storm and tissue damage, our results suggest that STAT3 may play a previously unsuspected role in H5N1 pathogenesis.

  10. Distribution and dynamics of risk factors associated with highly pathogenic avian influenza H5N1.

    PubMed

    Zhang, L; Guo, Z W; Bridge, E S; Li, Y M; Xiao, X M

    2013-11-01

    Within China's Poyang Lake region, close interactions between wild migratory birds and domestic poultry are common and provide an opportunity for the transmission and subsequent outbreaks of highly pathogenic avian influenza (HPAI) virus. We overlaid a series of ecological factors associated with HPAI to map the risk of HPAI in relation to natural and anthropogenic variables, and we identified two hotspots for potential HPAI outbreaks in the Poyang Lake region as well as three corridors connecting the two hotspot areas. In hotspot I, there is potential for migratory birds to bring new avian influenza (AI) strains that can reassort with existing strains to form new AI viruses. Hotspot II features high-density poultry production where outbreaks of endemic AI viruses are likely. The three communication corridors that link the two hotspots further promote HPAI H5N1 transmission and outbreaks and lead to the persistence of AI viruses in the Poyang Lake region. We speculate that the region's unevenly distributed poultry supply-and-demand system might be a key factor inducing HPAI H5N1 transmission and outbreaks in the Poyang Lake region.

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Emergence of H5N1 high pathogenicity avian influenza strains in Indonesia that are resistant to vaccines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccines have been used to protect poultry in Asia against H5N1 high pathogenicity avian influenza (HPAI) since 2002. Reports of vaccine “failures” began to emerge in 2006 in Indonesia, with identification of clinical disease consistent with HPAI or isolation of H5N1 HPAIV in vaccinated flocks or in...

  13. H5N1 subtype highly pathogenic avian influenza virus isolated from healthy mallard captured in South Korea.

    PubMed

    Kim, Hye-Ryoung; Kim, Bang-Sil; Bae, You-Chan; Moon, Oun-Kyoung; Oem, Jae-Ku; Kang, Hyun-Mi; Choi, Jun-Gu; Lee, O-Soo; Lee, Youn-Jeong

    2011-08-05

    On December 7, 2010, H5N1 highly pathogenic avian influenza virus was isolated from a healthy mallard captured at the Mankyung River in South Korea. Phylogenetic analysis showed that this virus was classified into clade 2.3.2 and closely related to H5N1 viruses isolated from wild birds in Mongolia, Russia and China in 2009 and 2010.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  15. Efficacy of commercial vaccines in chickens and ducks against H5N1 highly pathogenic avian influenza viruses from Vietnam

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic (HP) H5N1 avian influenza (AI) viruses continue to circulate in Asia and have spread to other regions of the world. Though attempts at eradication of the viruses during various outbreaks have been successful for short periods of time, new strains of H5N1 viruses continue to emerge...

  16. Mapping H5N1 highly pathogenic avian influenza risk in Southeast Asia

    PubMed Central

    Gilbert, Marius; Xiao, Xiangming; Pfeiffer, Dirk U.; Epprecht, M.; Boles, Stephen; Czarnecki, Christina; Chaitaweesub, Prasit; Kalpravidh, Wantanee; Minh, Phan Q.; Otte, M. J.; Martin, Vincent; Slingenbergh, Jan

    2008-01-01

    The highly pathogenic avian influenza (HPAI) H5N1 virus that emerged in southern China in the mid-1990s has in recent years evolved into the first HPAI panzootic. In many countries where the virus was detected, the virus was successfully controlled, whereas other countries face periodic reoccurrence despite significant control efforts. A central question is to understand the factors favoring the continuing reoccurrence of the virus. The abundance of domestic ducks, in particular free-grazing ducks feeding in intensive rice cropping areas, has been identified as one such risk factor based on separate studies carried out in Thailand and Vietnam. In addition, recent extensive progress was made in the spatial prediction of rice cropping intensity obtained through satellite imagery processing. This article analyses the statistical association between the recorded HPAI H5N1 virus presence and a set of five key environmental variables comprising elevation, human population, chicken numbers, duck numbers, and rice cropping intensity for three synchronous epidemic waves in Thailand and Vietnam. A consistent pattern emerges suggesting risk to be associated with duck abundance, human population, and rice cropping intensity in contrast to a relatively low association with chicken numbers. A statistical risk model based on the second epidemic wave data in Thailand is found to maintain its predictive power when extrapolated to Vietnam, which supports its application to other countries with similar agro-ecological conditions such as Laos or Cambodia. The model's potential application to mapping HPAI H5N1 disease risk in Indonesia is discussed. PMID:18362346

  17. Hemagglutinin glycosylation modulates the pathogenicity and antigenicity of the H5N1 avian influenza virus.

    PubMed

    Zhang, Xiaojian; Chen, Sujuan; Jiang, Yi; Huang, Kai; Huang, Jun; Yang, Da; Zhu, Jingjing; Zhu, Yinbiao; Shi, Shaohua; Peng, Daxin; Liu, Xiufan

    2015-02-25

    The location and number of glycosylation in HA proteins exhibit large variations among H5 subtype avian influenza viruses (AIVs). To investigate the effect of glycosylation in the globular head of HA on the pathogenicity and antigenicity of H5N1 AIVs, seven rescued AIVs differing in their glycosylation patterns (144N, 158N and 169N) within the HA globular head of A/Mallard/Huadong/S/2005 were generated using site directed mutagenesis. Results showed that loss of glycosylation 158N was the prerequisite for H5 AIV binding to the α2,6-linked receptor. Only in conjunction with the removal of the 158N glycosylation, the H5 AIVs harboring both 144N and 169N glycosylations obtained an optimal binding preference to the α2,6-linked receptor. Compared with the wild-type virus, growth of viruses lacking glycosylation at either 158N or 169N was significantly reduced both in MDCK and A549 cells, while replication of viruses with additional glycosylation 144N was significantly promoted. Mutant viruses with loss of 158N or 169N glycosylation sites showed increased pathogenicity, systemic spread and pulmonary inflammation in mice compared to the wild-type H5N1 virus. In addition, chicken studies demonstrated that inactivated de-glycosylation 169N mutant induced cross-reaction HI and neutralization antibody against various clades of H5N1 AIVs. Moreover, this type of glycan pattern vaccine virus provided better cross-protection in chickens compared to wild-type vaccine virus. Thus, the glycosylation alteration of HA should be considered in the global surveillance and vaccine design of H5 subtype AIVs.

  18. Insight into Alternative Approaches for Control of Avian Influenza in Poultry, with Emphasis on Highly Pathogenic H5N1

    PubMed Central

    Abdelwhab, E. M.; Hafez, Hafez M.

    2012-01-01

    Highly pathogenic avian influenza virus (HPAIV) of subtype H5N1 causes a devastating disease in poultry but when it accidentally infects humans it can cause death. Therefore, decrease the incidence of H5N1 in humans needs to focus on prevention and control of poultry infections. Conventional control strategies in poultry based on surveillance, stamping out, movement restriction and enforcement of biosecurity measures did not prevent the virus spreading, particularly in developing countries. Several challenges limit efficiency of the vaccines to prevent outbreaks of HPAIV H5N1 in endemic countries. Alternative and complementary approaches to reduce the current burden of H5N1 epidemics in poultry should be encouraged. The use of antiviral chemotherapy and natural compounds, avian-cytokines, RNA interference, genetic breeding and/or development of transgenic poultry warrant further evaluation as integrated intervention strategies for control of HPAIV H5N1 in poultry. PMID:23202521

  19. Generation of an attenuated H5N1 avian influenza virus vaccine with all eight genes from avian viruses.

    PubMed

    Shi, Huoying; Liu, Xiu Fan; Zhang, Xiaorong; Chen, Sujuan; Sun, Lei; Lu, Jianhong

    2007-10-16

    In the face of disease outbreaks in poultry and the potential pandemic threat to humans caused by the highly pathogenic avian influenza viruses (HPAIVs) of H5N1 subtype, improvement in biosecurity and the use of inactivated vaccines are two main options for the control of this disease. Vaccine candidates of influenza A viruses of H5N1 subtype have been generated in several laboratories by plasmid-based reverse genetics with hemagglutinin (HA) and neuraminidase (NA) genes from the epidemic strains of avian viruses in a background of internal genes from the vaccine donor strain of human strains, A/Puerto Rico/8/34 (PR8). These reassortant viruses containing genes from both avian and human viruses might impose biosafety concerns, also may be do if C4/F AIV would be a live attenuated vaccine or cold-adaptive strain vaccine. In order to generate better and safer vaccine candidate viruses, we genetically constructed attenuated reassortant H5N1 influenza A virus, designated as C4/F AIV, by plasmid-based reverse genetics with all eight genes from the avian strains. The C4/F AIV virus contained HA and NA genes from an epidemic strain A/Chicken/Huadong/04 (H5N1) (C4/H5N1) in a background of internal genes derived from a low pathogenic strain of A/Chicken/F/98(H9N2). The reassortant virus was attenuated by removal of the multibasic amino acid motif in the HA gene by mutation and deletion (from PQRERRRKKR (downward arrow) G to PQIETR (downward arrow) G). The intravenous pathogenicity index (IVPI) of C4/F AIV virus was 0, whereas that of the donor virus C4/H5N1 was 3.0. The virus HA titer of C4/H5N1 in the allantoic fluid from infected embryonated eggs was as high as 1:2048. The inactivated vaccine prepared from the reassortant virus C4/F AIV-induced high HI titer in vaccinated chickens and gave 100% protection when challenged with highly pathogenic avian influenza virus of H5N1 subtype.

  20. Origin and evolution of highly pathogenic H5N1 avian influenza in Asia.

    PubMed

    Sims, L D; Domenech, J; Benigno, C; Kahn, S; Kamata, A; Lubroth, J; Martin, V; Roeder, P

    2005-08-06

    Outbreaks of highly pathogenic avian influenza caused by H5N1 viruses were reported almost simultaneously in eight neighbouring Asian countries between December 2003 and January 2004, with a ninth reporting in August 2004, suggesting that the viruses had spread recently and rapidly. However, they had been detected widely in the region in domestic waterfowl and terrestrial poultry for several years before this, and the absence of widespread disease in the region before 2003, apart from localised outbreaks in the Hong Kong Special Autonomous Region (SAR), is perplexing. Possible explanations include limited virus excretion by domestic waterfowl infected with H5N1, the confusion of avian influenza with other serious endemic diseases, the unsanctioned use of vaccines, and the under-reporting of disease as a result of limited surveillance. There is some evidence that the excretion of the viruses by domestic ducks had increased by early 2004, and there is circumstantial evidence that they can be transmitted by wild birds. The migratory birds from which viruses have been isolated were usually sick or dead, suggesting that they would have had limited potential for carrying the viruses over long distances unless subclinical infections were prevalent. However, there is strong circumstantial evidence that wild birds can become infected from domestic poultry and potentially can exchange viruses when they share the same environment. Nevertheless, there is little reason to believe that wild birds have played a more significant role in spreading disease than trade through live bird markets and movement of domestic waterfowl. Asian H5N1 viruses were first detected in domestic geese in southern China in 1996. By 2000, their host range had extended to domestic ducks, which played a key role in the genesis of the 2003/04 outbreaks. The epidemic was not due to the introduction and spread of a single virus but was caused by multiple viruses which were genotypically linked to the Goose

  1. Engaging the normative question in the H5N1 avian influenza mutation experiments

    PubMed Central

    2013-01-01

    Introduction In recent time there has been ample discussion concerning censorship of research conducted in two labs involved in avian influenza virus research. Much of the debate has centered on the question whether the methods and results should reach to open disclosure given the “dual use” nature of this research which can be used for nefarious purposes. Methods This paper reviews the discussion to date but centers on epistemological issues associated with initial justification of this research and what this entails for continuation of this research despite US governmental biosecurity concerns. The question here is whether there was reasonable moral warrant for genetic alteration of the H5N1 influenza virus. Conclusion The paper concludes with philosophical (ethical) justification for continuation of this research. PMID:24006905

  2. Ecologic Immunology of Avian Influenza (H5N1) in Migratory Birds

    PubMed Central

    Stilianakis, Nikolaos I.

    2007-01-01

    The claim that migratory birds are responsible for the long-distance spread of highly pathogenic avian influenza viruses of subtype H5N1 rests on the assumption that infected wild birds can remain asymptomatic and migrate long distances unhampered. We critically assess this claim from the perspective of ecologic immunology, a research field that analyzes immune function in an ecologic, physiologic, and evolutionary context. Long-distance migration is one of the most demanding activities in the animal world. We show that several studies demonstrate that such prolonged, intense exercise leads to immunosuppression and that migratory performance is negatively affected by infections. These findings make it unlikely that wild birds can spread the virus along established long-distance migration pathways. However, infected, symptomatic wild birds may act as vectors over shorter distances, as appears to have occurred in Europe in early 2006. PMID:17953082

  3. An outbreak of highly pathogenic H5N1 avian influenza in Korea, 2008.

    PubMed

    Kim, Hye-Ryoung; Park, Choi-Kyu; Lee, Youn-Jeong; Woo, Gye-Hyeong; Lee, Kyoung-Ki; Oem, Jae-Ku; Kim, Seong-Hee; Jean, Young-Hwa; Bae, Yu-Chan; Yoon, Soon-Seek; Roh, In-Soon; Jeong, Ok-Mi; Kim, Ha-Young; Choi, Jeong-Soo; Byun, Jae-Won; Song, Yun-Kyung; Kwon, Jun-Hun; Joo, Yi-Seok

    2010-03-24

    In spite of intensive surveillance programs for the control of HPAI, an outbreak of highly pathogenic avian influenza (HPAI) H5N1 in Korea in April 2008 caused serious damage to poultry farms, as did previous outbreaks in 2003/2004 and 2006/2007. Six viruses were selected from the Korean 2008 isolates for genetic analysis, and all eight gene segments from each of the influenza viruses were sequenced. A phylogenetic analysis showed that all of the viruses were of the same virus type and that the hemagglutinin (HA) gene was clustered with that of clade 2.3.2 viruses. However, the internal and neuraminidase (NA) genes were closely related to those of the clade 2.3.4 viruses (recent human and bird isolates from Southeast Asia).

  4. Fluorescence biosensor based on CdTe quantum dots for specific detection of H5N1 avian influenza virus

    NASA Astrophysics Data System (ADS)

    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.

  5. Genomic analysis of influenza A viruses, including avian flu (H5N1) strains.

    PubMed

    Ahn, Insung; Jeong, Byeong-Jin; Bae, Se-Eun; Jung, Jin; Son, Hyeon S

    2006-01-01

    This study was designed to conduct genomic analysis in two steps, such as the overall relative synonymous codon usage (RSCU) analysis of the five virus species in the orthomyxoviridae family, and more intensive pattern analysis of the four subtypes of influenza A virus (H1N1, H2N2, H3N2, and H5N1) which were isolated from human population. All the subtypes were categorized by their isolated regions, including Asia, Europe, and Africa, and most of the synonymous codon usage patterns were analyzed by correspondence analysis (CA). As a result, influenza A virus showed the lowest synonymous codon usage bias among the virus species of the orthomyxoviridae family, and influenza B and influenza C virus were followed, while suggesting that influenza A virus might have an advantage in transmitting across the species barrier due to their low codon usage bias. The ENC values of the host-specific HA and NA genes represented their different HA and NA types very well, and this reveals that each influenza A virus subtype uses different codon usage patterns as well as the amino acid compositions. In NP, PA and PB2 genes, most of the virus subtypes showed similar RSCU patterns except for H5N1 and H3N2 (A/HK/1774/1999) subtypes which were suspected to be transmitted across the species barrier, from avian and porcine species to human beings, respectively. This distinguishable synonymous codon usage patterns in non-human origin viruses might be useful in determining the origin of influenza A viruses in genomic levels as well as the serological tests. In this study, all the process, including extracting sequences from GenBank flat file and calculating codon usage values, was conducted by Java codes, and these bioinformatics-related methods may be useful in predicting the evolutionary patterns of pandemic viruses.

  6. Rapid Emergence of Highly Pathogenic Avian Influenza Subtypes from a Subtype H5N1 Hemagglutinin Variant.

    PubMed

    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.

  7. Genetic characterization of highly pathogenic avian influenza H5N1 viruses isolated from naturally infected pigeons in Egypt.

    PubMed

    Elgendy, Emad Mohamed; Watanabe, Yohei; Daidoji, Tomo; Arai, Yasuha; Ikuta, Kazuyoshi; Ibrahim, Madiha Salah; Nakaya, Takaaki

    2016-12-01

    Avian influenza viruses impose serious public health burdens with significant mortality and morbidity not only in poultry but also in humans. While poultry susceptibility to avian influenza virus infection is well characterized, pigeons have been thought to have low susceptibility to these viruses. However, recent studies reported natural pigeon infections with highly pathogenic avian influenza H5N1 viruses. In Egypt, which is one of the H5N1 endemic areas for birds, pigeons are raised in towers built on farms in backyards and on house roofs, providing a potential risk for virus transmission from pigeons to humans. In this study, we performed genetic analysis of two H5N1 virus strains that were isolated from naturally infected pigeons in Egypt. Genetic and phylogenetic analyses showed that these viruses originated from Egyptian H5N1 viruses that were circulating in chickens or ducks. Several unique mutations, not reported before in any Egyptian isolates, were detected in the internal genes (i.e., polymerase residues PB1-V3D, PB1-K363R, PA-A369V, and PA-V602I; nucleoprotein residue NP-R38K; and nonstructural protein residues NS1-D120N and NS2-F55C). Our findings suggested that pigeons are naturally infected with H5N1 virus and can be a potential reservoir for transmission to humans, and showed the importance of genetic analysis of H5N1 internal genes.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. Survivability of Eurasian H5N1 highly pathogenic avian influenza viruses in water varies between strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquatic habitats play critical role in the transmission and maintenance of low pathogenic avian influenza (LPAI) viruses in wild waterfowl; however the importance of these environments in the ecology of H5N1 highly pathogenic avian influenza (HPAI) viruses is unknown. In laboratory-based studies, L...

  10. Identification of mammalian-adapting mutations in the polymerase complex of an avian H5N1 influenza virus.

    PubMed

    Taft, Andrew S; Ozawa, Makoto; Fitch, Adam; Depasse, Jay V; Halfmann, Peter J; Hill-Batorski, Lindsay; Hatta, Masato; Friedrich, Thomas C; Lopes, Tiago J S; Maher, Eileen A; Ghedin, Elodie; Macken, Catherine A; Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-06-17

    Avian influenza viruses of the H5N1 subtype pose a serious global health threat due to the high mortality (>60%) associated with the disease caused by these viruses and the lack of protective antibodies to these viruses in the general population. The factors that enable avian H5N1 influenza viruses to replicate in humans are not completely understood. Here we use a high-throughput screening approach to identify novel mutations in the polymerase genes of an avian H5N1 virus that confer efficient polymerase activity in mammalian cells. Several of the identified mutations (which have previously been found in natural isolates) increase viral replication in mammalian cells and virulence in infected mice compared with the wild-type virus. The identification of amino-acid mutations in avian H5N1 influenza virus polymerase complexes that confer increased replication and virulence in mammals is important for the identification of circulating H5N1 viruses with an increased potential to infect humans.

  11. Identification of mammalian-adapting mutations in the polymerase complex of an avian H5N1 influenza virus

    PubMed Central

    Taft, Andrew S.; Ozawa, Makoto; Fitch, Adam; Depasse, Jay V.; Halfmann, Peter J.; Hill-Batorski, Lindsay; Hatta, Masato; Friedrich, Thomas C.; Lopes, Tiago J. S.; Maher, Eileen A.; Ghedin, Elodie; Macken, Catherine A.; Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-01-01

    Avian influenza viruses of the H5N1 subtype pose a serious global health threat due to the high mortality (>60%) associated with the disease caused by these viruses and the lack of protective antibodies to these viruses in the general population. The factors that enable avian H5N1 influenza viruses to replicate in humans are not completely understood. Here we use a high-throughput screening approach to identify novel mutations in the polymerase genes of an avian H5N1 virus that confer efficient polymerase activity in mammalian cells. Several of the identified mutations (which have previously been found in natural isolates) increase viral replication in mammalian cells and virulence in infected mice compared with the wild-type virus. The identification of amino-acid mutations in avian H5N1 influenza virus polymerase complexes that confer increased replication and virulence in mammals is important for the identification of circulating H5N1 viruses with an increased potential to infect humans. PMID:26082035

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

    USGS Publications Warehouse

    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

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

    PubMed

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

    2011-03-01

    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

  14. Isolation and identification of highly pathogenic avian influenza virus subtype H5N1 in peafowl (Pavo cristatus).

    PubMed

    Ismail, Mahmoud Moussa; Khan, Owais Ahmed; Cattoli, Giovanni; Lu, Huaguang

    2010-03-01

    An outbreak of highly pathogenic avian influenza (HPAI) virus subtype H5N1 was first diagnosed in a "backyard" flock of peafowl (Pavo cristatus) raised on palace premises in the Kingdom of Saudi Arabia in December 3, 2007. The flock consisted of 40 peafowl, and their ages ranged from 3 to 5 years old. Affected birds suffered from depression, anorexia, and white diarrhea. Four dead birds were submitted for HPAI diagnosis at the Central Veterinary Diagnostic Laboratory in Riyadh. Brain and liver tissues and tracheal and cloacal swabs were taken from the dead birds and processed for a real-time reverse transcriptase (RT)-PCR test and virus isolation in specific-pathogen-free embryonating chicken eggs. The H5N1 subtype of avian influenza virus was isolated from the four dead birds and identified by a real-time RT-PCR before and after egg inoculation. The virus isolates were characterized as HPAI H5N1 virus by sequencing analysis. Phylogenetic comparisons revealed that the H5N1 viruses isolated from peafowl belong to the genetic clade 2.2 according to the World Health Organization nomenclature. The peafowl H5N1 virus falls into 2.2.2 sublineage II and clusters with the H5N1 viruses isolated from poultry in Saudi Arabia in 2007-08.

  15. Re-emergence of amantadine-resistant variants among highly pathogenic avian influenza H5N1 viruses in Egypt.

    PubMed

    El-Shesheny, Rabeh; Bagato, Ola; Kandeil, Ahmed; Mostafa, Ahmed; Mahmoud, Sara H; Hassanneen, Hamdi M; Webby, Richard J; Ali, Mohamed A; Kayali, Ghazi

    2016-12-01

    Highly pathogenic avian influenza (HPAI) H5N1 virus continues to undergo substantial evolution. Emergence of antiviral resistance among H5N1 avian influenza viruses is a major challenge in the control of pandemic influenza. Numerous studies have focused on the genetic and evolutionary dynamics of the hemagglutinin and neuraminidase genes; however, studies on the susceptibility of HPAI H5N1 viruses to amantadine and genetic diversity of the matrix (M) gene are limited. Accordingly, we studied the amantadine susceptibility of the HPAI H5N1 viruses isolated in Egypt during 2006-2015 based on genotypic and phenotypic characteristics. We analyzed data on 253 virus sequences and constructed a phylogenetic tree to calculate selective pressures on sites in the M2 gene associated with amantadine-resistance among different clades. Selection pressure was identified in the transmembrane domain of M2 gene at positions 27 and 31. Amantadine-resistant variants emerged in 2007 but were not circulating between 2012 and 2014. By 2015, amantadine-resistant HPAI H5N1 viruses re-emerged. This may be associated with the uncontrolled prescription of amantadine for prophylaxis and control of avian influenza infections in the poultry farm sector in Egypt. More epidemiological research is required to verify this observation.

  16. Characterization of the H5N1 highly pathogenic avian influenza virus derived from wild pikas in China.

    PubMed

    Zhou, Jiyong; Sun, Wenbo; Wang, Junhua; Guo, Junqing; Yin, Wei; Wu, Nanping; Li, Lanjuan; Yan, Yan; Liao, Ming; Huang, Yu; Luo, Kaijian; Jiang, Xuetao; Chen, Hualan

    2009-09-01

    The highly pathogenic H5N1 avian influenza virus emerged from China in 1996 and has spread across Eurasia and Africa, with a continuous stream of new cases of human infection appearing since the first large-scale outbreak among migratory birds at Qinghai Lake. The role of wild birds, which are the natural reservoirs for the virus, in the epidemiology of the H5N1 virus has raised great public health concern, but their role in the spread of the virus within the natural ecosystem of free-ranging terrestrial wild mammals remains unclear. In this study, we investigated H5N1 virus infection in wild pikas in an attempt to trace the circulation of the virus. Seroepidemiological surveys confirmed a natural H5N1 virus infection of wild pikas in their native environment. The hemagglutination gene of the H5N1 virus isolated from pikas reveals two distinct evolutionary clades, a mixed/Vietnam H5N1 virus sublineage (MV-like pika virus) and a wild bird Qinghai (QH)-like H5N1 virus sublineage (QH-like pika virus). The amino acid residue (glutamic acid) at position 627 encoded by the PB2 gene of the MV-like pika virus was different from that of the QH-like pika virus; the residue of the MV-like pika virus was the same as that of the goose H5N1 virus (A/GS/Guangdong [GD]/1/96). Further, we discovered that in contrast to the MV-like pika virus, which is nonpathogenic to mice, the QH-like pika virus is highly pathogenic. To mimic the virus infection of pikas, we intranasally inoculated rabbits, a species closely related to pikas, with the H5N1 virus of pika origin. Our findings first demonstrate that wild pikas are mammalian hosts exposed to H5N1 subtype avian influenza viruses in the natural ecosystem and also imply a potential transmission of highly pathogenic avian influenza virus from wild mammals into domestic mammalian hosts and humans.

  17. Interventions for avian influenza A (H5N1) risk management in live bird market networks.

    PubMed

    Fournié, Guillaume; Guitian, Javier; Desvaux, Stéphanie; Cuong, Vu Chi; Dung, Do Huu; Pfeiffer, Dirk Udo; Mangtani, Punam; Ghani, Azra C

    2013-05-28

    Highly pathogenic avian influenza virus subtype H5N1 is endemic in Asia, with live bird trade as a major disease transmission pathway. A cross-sectional survey was undertaken in northern Vietnam to investigate the structure of the live bird market (LBM) contact network and the implications for virus spread. Based on the movements of traders between LBMs, weighted and directed networks were constructed and used for social network analysis and individual-based modeling. Most LBMs were connected to one another, suggesting that the LBM network may support large-scale disease spread. Because of cross-border trade, it also may promote transboundary virus circulation. However, opportunities for disease control do exist. The implementation of thorough, daily disinfection of the market environment as well as of traders' vehicles and equipment in only a small number of hubs can disconnect the network dramatically, preventing disease spread. These targeted interventions would be an effective alternative to the current policy of a complete ban of LBMs in some areas. Some LBMs that have been banned still are very active, and they likely have a substantial impact on disease dynamics, exhibiting the highest levels of susceptibility and infectiousness. The number of trader visits to markets, information that can be collected quickly and easily, may be used to identify LBMs suitable for implementing interventions. This would not require prior knowledge of the force of infection, for which laboratory-confirmed surveillance would be necessary. These findings are of particular relevance for policy development in resource-scarce settings.

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

    PubMed Central

    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

    2015-01-01

    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. PMID:26259704

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

    PubMed Central

    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

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

    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

    2017-03-06

    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.

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

    PubMed

    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.

  4. Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

    PubMed Central

    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. PMID:19479053

  5. Migration of whooper swans and outbreaks of highly pathogenic avian influenza H5N1 virus in Eastern Asia

    USGS Publications Warehouse

    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.

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

    PubMed

    Arafa, Abdelsatar; El-Masry, Ihab; Khoulosy, Shereen; Hassan, Mohammed K; Soliman, Moussa; Fasanmi, Olubunmi G; Fasina, Folorunso O; Dauphin, Gwenaelle; Lubroth, Juan; Jobre, Yilma M

    2016-11-28

    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.

  7. Genetic evidence for avian influenza H5N1 viral transmission along the Black Sea-Mediterranean Flyway.

    PubMed

    Zhou, Sen; Tian, Huaiyu; Wu, Xiaoxu; Xu, Bo; Yang, Jing; Chan, Karen Kie Yan; Huang, Shanqian; Dong, Lu; Brownstein, John; Xu, Bing

    2016-09-01

    The current epidemic of highly pathogenic avian influenza H5N1 virus is considered to pose a significant threat to the health of wild and domestic avian species, and even to human beings. The Black Sea-Mediterranean Flyway is one of the most important epidemic areas of H5N1. However, the epidemic along this flyway has not been fully explored. To better understand the role of hosts in the spread and evolution of H5N1 virus along the flyway, a phylogeographic study was conducted using haemagglutinin (HA) gene sequences obtained during 2005-2013. To infer phylodynamic spread in time and space, we used a flexible Bayesian statistical framework and modelled viral spatial diffusion as a continuous-time Markov-chain process along time-measured genealogies. Our results revealed that H5N1 virus isolated from wild birds showed an increase in genetic variation of HA gene from 2005-2007. The mean genetic distance of viruses isolated from poultry reached its peak in 2010, and dropped in 2011, increasing again in 2012-2013. The reconstruction of virus circulation revealed a different viral-migration network of H5N1 virus by different hosts. Western Russia constituted a link in viral migration from Russia to Europe and Africa. Cross-species transmission of H5N1 viruses predominated in the migration network of the Black Sea-Mediterranean Flyway. This might be due to the migration of birds across long distances and interaction between local poultry and migratory birds. Additionally, the short-distance spread of H5N1 viruses among poultry followed local transportation networks. Such findings will aid in developing effective disease control and prevention strategies.

  8. Characaterization of H5N1 highly pathogenic avian influenza viruses isolated from poultry in Pakistan 2006-2008

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nine avian influenza viruses (AIV), H5N1 subtype, were isolated from dead poultry in the Karachi region of Pakistan from 2006-2008. The intravenous pathogenicity indices and HA protein cleavage sites of all nine viruses were consistent with highly pathogenic AIV. Based on phylogenetic analysis of ...

  9. Complete Genome Sequence of the First H5N1 Avian Influenza Virus Isolated from Chickens in Lebanon in 2016

    PubMed Central

    Ibrahim, Elias; Sirawan, Abeer; El-Bazzal, Bassel; El Hage, Jeanne; Abi Said, Mounir; Kandeil, Ahmed; Ali, Mohamed A.

    2016-01-01

    We generated the full genome of a highly pathogenic H5N1 avian influenza virus that caused an outbreak on a chicken farm in Lebnaon in April 2016. Analysis revealed that the virus belonged to clade 2.3.2.1c that recently caused outbreaks in West Africa and the United Arab Emirates. PMID:27795243

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

    PubMed

    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.

  11. Avian influenza H5N1 in naturally infected domestic cat.

    PubMed

    Songserm, Thaweesak; Amonsin, Alongkorn; Jam-on, Rungroj; Sae-Heng, Namdee; Meemak, Noppadol; Pariyothorn, Nuananong; Payungporn, Sunchai; Theamboonlers, Apiradee; Poovorawan, Yong

    2006-04-01

    We report H5N1 virus infection in a domestic cat infected by eating a pigeon carcass. The virus isolated from the pigeon and the cat showed the same cluster as the viruses obtained during the outbreak in Thailand. Since cats are common house pets, concern regarding disease transmission to humans exists.

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

    USGS Publications Warehouse

    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.

  13. Evaluation of a high-pathogenicity H5N1 avian influenza A virus isolated from duck meat.

    PubMed

    Tumpey, T M; Suarez, D L; Perkins, L E L; Senne, D A; Lee, J; Lee, Y J; Mo, I P; Sung, H W; Swayne, D E

    2003-01-01

    The introduction of an influenza A virus possessing a novel hemagglutinin (HA) into an immunologically naive human population has the potential to cause severe disease and death. Such was the case in 1997 in Hong Kong, where H5N1 influenza was transmitted to humans from infected poultry. Because H5N1 viruses are still isolated from domestic poultry in southern China, there needs to be continued surveillance of poultry and characterization of virus subtypes and variants. This study provides molecular characterization and evaluation of pathogenesis of a recent H5N1 virus isolated from duck meat that had been imported to South Korea from China. The HA gene of A/Duck/Anyang/AVL-1/01 (H5N1) isolate was found to be closely related to the Hong Kong/97 H5N1 viruses. This virus also contained multiple basic amino acids adjacent to the cleavage site between HA1 and HA2, characteristic of high-pathogenicity avian influenza viruses (HPAI). The pathogenesis of this virus was characterized in chickens, ducks, and mice. The DK/Anyang/AVL-1/01 isolate replicated well in all species and resulted in 100% and 22% lethality for chickens and mice, respectively. No clinical signs of disease were observed in DK/Anyang/AVL-1/01-inoculated ducks, but high titers of infectious virus could be detected in multiple tissues and oropharyngeal swabs. The presence of an H5N1 influenza virus in ducks bearing a HA gene that is highly similar to those of the pathogenic 1997 human/poultry H5N1 viruses raises the possibility of reintroduction of HPAI to chickens and humans.

  14. Avian Influenza H5N1 Surveillance and its Dynamics in Poultry in Live Bird Markets, Egypt.

    PubMed

    ElMasry, I; Elshiekh, H; Abdlenabi, A; Saad, A; Arafa, A; Fasina, F O; Lubroth, J; Jobre, Y M

    2015-11-25

    H5N1, a highly pathogenic avian influenza (H5N1 HPAI), is an endemic disease that is significant for public health in Egypt. Live bird markets (LBMs) are widespread in Egypt and play an important role in HPAI disease dynamics. The aim of the study was to evaluate the H5N1 HPAI prevalence in representative LBMs from 2009 to 2014, assess the effects of other variables and evaluate past outbreaks and human cases. It was found that ducks and geese are high-risk species and that the prevalence of H5N1 HPAI was higher immediately after the political crises of 2011. The end of a calendar year (June to December) was a high-risk period for positive samples, and the risk in urban LBMs was twice the risk in rural LBMs. Winter and political unrest was associated with higher H5N1 HPAI prevalence. Both human and poultry populations will continue to rise in Egypt, so continued poultry outbreaks are likely to be linked to more human cases. LBMs will continue to play a role in the dynamics of poultry disease in Egypt, and there is a need to reorganize markets in terms of biosecurity and traceability. It may also be beneficial to reduce inter-governorate inter-regional movements associated with poultry trade through promotion of regional trade or in the alternative provide sanitary features along the poultry market chain to reduce the speed of H5N1 HPAI infections. Policy formulation, design and enforcement must be pro-poor, and consideration of the sociocultural and economic realities in Egypt is important. The LBMs provide ideal platforms to carry out sound surveillance plans and mitigate zoonotic risks of H5N1 HPAI to humans.

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

    PubMed

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

    PubMed Central

    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

    2015-01-01

    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. PMID:26691585

  17. Sparse serological evidence of H5N1 avian influenza virus infections in domestic cats, northeastern China.

    PubMed

    Sun, Lingshuang; Zhou, Pei; He, Shuyi; Luo, Yongfeng; Jia, Kun; Fu, Cheng; Sun, Yao; He, Huamei; Tu, Liqing; Ning, Zhangyong; Yuan, Ziguo; Wang, Heng; Li, Shoujun; Yuan, Liguo

    2015-05-01

    Today the cross-species transmission of avian influenza viruses (AIV) are a great concern. A number of AIV strains are now enzootic among poultry, with H9N2 and highly pathogenic H5N1 AIV strains prevalent in China. H5N1 strains have been recognized to infect zoo and domestic feline species. In this serological study we sought to examine evidence that H5N1 strains have infected domestic cats in northeastern China. In 2013, we conducted a cross-sectional serological study of 916 healthy cats in Heilongjian, Jilin, and Liaonin Provinces. Sera were screened with a hemagglutinin inhibition (HI) assay and seropositive specimens (HI ≥ 1:20) were further evaluated with a microneutralization (MN) assay against a clade 2.3.2 H5N1 AIV, a H9N2 AIV, A (H1N1)pdm09, and a canine H3N2 virus. While ∼2% of cats had elevated HI assays against H5N1, no elevations were confirmed (MN ≥ 1:80). These data serve as baseline for future surveillance for AIV infections among domestic cats. Conducting such surveillance seems important for geographical areas recognized as endemic for AIVs. This is especially true for countries such as China where domestic cats and poultry are often in close contact.

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

    PubMed

    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.

  19. Role of Host Cytokine Responses in the Pathogenesis of Avian H5N1 Influenza Viruses in Mice▿

    PubMed Central

    Szretter, Kristy J.; Gangappa, Shivaprakash; Lu, Xuihua; Smith, Chalanda; Shieh, Wun-Ju; Zaki, Sherif R.; Sambhara, Suryaprakash; Tumpey, Terrence M.; Katz, Jacqueline M.

    2007-01-01

    Highly pathogenic avian H5N1 influenza viruses are now widespread in poultry in Asia and have recently spread to some African and European countries. Interspecies transmission of these viruses to humans poses a major threat to public health. To better understand the basis of pathogenesis of H5N1 viruses, we have investigated the role of proinflammatory cytokines in transgenic mice deficient in interleukin-6 (IL-6), macrophage inflammatory protein 1 alpha (MIP-1α), IL-1 receptor (IL-1R), or tumor necrosis factor receptor 1 (TNFR1) by the use of two avian influenza A viruses isolated from humans, A/Hong Kong/483/97 (HK/483) and A/Hong Kong/486/97 (HK/486), which exhibit high and low lethality in mice, respectively. The course of disease and the extent of virus replication and spread in IL-6- and MIP-1α-deficient mice were not different from those observed in wild-type mice during acute infection with 1,000 50% mouse infective doses of either H5N1 virus. However, with HK/486 virus, IL-1R-deficient mice exhibited heightened morbidity and mortality due to infection, whereas no such differences were observed with the more virulent HK/483 virus. Furthermore, TNFR1-deficient mice exhibited significantly reduced morbidity following challenge with either H5N1 virus but no difference in viral replication and spread or ultimate disease outcome compared with wild-type mice. These results suggest that TNF-α may contribute to morbidity during H5N1 influenza virus infection, while IL-1 may be important for effective virus clearance in nonlethal H5N1 disease. PMID:17182684

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

    PubMed

    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.

  1. Determination of efficacious vaccine seed strains for use against Egyptian H5N1 highly pathogenic avian influenza viruses through antigenic cartography and in vivo challenge studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 2006, there have been reported outbreaks of H5N1 highly pathogenic avian influenza (HPAI) in vaccinated chickens in Africa and Asia. This study provides experimental data for selection of efficacious H5N1 vaccine seed strains against recently circulating strains of H5N1 HPAI viruses in Egypt....

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

    PubMed

    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.

  3. Genetic characterization of highly pathogenic H5N1 avian influenza virus from live migratory birds in Bangladesh.

    PubMed

    Parvin, Rokshana; Kamal, Abu H M; Haque, Md E; Chowdhury, Emdadul H; Giasuddin, Mohammed; Islam, Mohammad R; Vahlenkamp, Thomas W

    2014-12-01

    Since the first outbreak of highly pathogenic avian influenza virus (HPAIV) subtype H5N1 in Bangladesh in 2007, the virus has been circulating among domestic poultry causing severe economic losses. To investigate the presence of HPAIV H5N1 in migratory birds and their potential role in virus spread, 205 pools of fecal samples from live migratory birds were analyzed. Here, the first virus isolation and genome characterization of two HPAIV H5N1 isolates from migratory birds (A/migratory bird/Bangladesh/P18/2010 and A/migratory bird/Bangladesh/P29/2010)are described. Full-length amplification, sequencing, and a comprehensive phylogenetic analysis were performed for HA, NA, M, NS, NP, PA, PB1, and PB2 gene segments. The selected migratory bird isolates belong to clade 2.3.2.1 along with recent Bangladeshi isolates from chickens, ducks, and crows which grouped in the same cluster with contemporary South and South-East Asian isolates. The studied isolates were genetically similar to other H5N1 isolates from different species within the respective clade although some unique amino acid substitutions were observed among them. Migratory birds remain a real threat for spreading pathogenic avian influenza viruses across the continent and introduction of new strains into Bangladesh.

  4. Highly pathogenic avian influenza virus subtype H5N1 in Mute swans in the Czech Republic.

    PubMed

    Nagy, Alexander; Machova, Jirina; Hornickova, Jitka; Tomci, Miroslav; Nagl, Ivan; Horyna, Bedrich; Holko, Ivan

    2007-02-25

    In order to determine the actual prevalence of avian influenza viruses (AIV) in wild birds in the Czech Republic extensive surveillance was carried out between January and April 2006. A total of 2101 samples representing 61 bird species were examined for the presence of influenza A by using PCR, sequencing and cultivation on chicken embryos. AIV subtype H5N1 was detected in 12 Mute swans (Cygnus olor). The viruses were determined as HPAI (highly pathogenic avian influenza) and the hemagglutinin sequence was closely similar to A/mallard/Italy/835/06 and A/turkey/Turkey/1194/05. Following the first H5N1 case, about 300 wild birds representing 33 species were collected from the outbreak region and tested for the presence of AIV without any positive result. This is the first report of highly pathogenic avian influenza subtype H5N1 in the Czech Republic. The potential role of swan as an effective vector of avian influenza virus is also discussed.

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

    PubMed

    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.

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

    PubMed

    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.

  7. Antigenic analysis of H5N1 highly pathogenic avian influenza viruses circulating in Egypt (2006-2012).

    PubMed

    Ibrahim, Mahmoud; Eladl, Abdel-Fattah; Sultan, Hesham A; Arafa, Abdel Satar; Abdel Razik, Alaa G; Abd El Rahman, Sahar; El-Azm, Kamel I Abou; Saif, Yehia M; Lee, Chang-Won

    2013-12-27

    The highly pathogenic avian influenza (HPAI) H5N1 in Egypt circulated continuously after its introduction in February 2006 with substantial economic losses and frequent human infections. Phylogenetic analysis of the available HA sequences revealed the presence of two main sublineages; the classic 2.2.1 and the variant 2.2.1.1. The classic 2.2.1 had subdivided into two clusters of viruses; cluster C1 contained the originally introduced virus and isolates from 2006 to 2009 and cluster C2 emerged in 2007 and continues to circulate. The variant 2.2.1.1 represents the isolates mainly from chickens and subdivided into two clusters; cluster V1 contains isolates from 2007 to 2009 and cluster V2 contains isolates from 2008 to 2011. Sequence analysis revealed 28 amino acid mutations in the previously reported antigenic sites and high evolution rate which may be due to selective pressure from vaccination and/or natural infection. Antigenic analysis of 18 H5N1 isolates from 2006 to 2012 that represent different clusters was conducted using hemagglutination inhibition (HI) and virus neutralization (VN) assays using hyperimmune sera produced by immunizing SPF chickens with inactivated whole-virus. Antigenic relatedness of ancestral Egyptian H5N1 isolate (459-3/06) with other isolates ranged from 30.7% to 79.1% indicating significant antigenic drift of the H5N1 viruses from the ancestral strains. The antigenic relatedness between C2 and V2 clusters ranged from 28.9% to 68% supporting the need for vaccine seed strains from both clusters. Interestingly, A/CK/EG/1709-6/2008 H5N1 strain showed a broad cross reactivity against viruses in different H5N1 clusters (antigenic relatedness ranged from 63.9% to 85.8%) demonstrating a potential candidate as a vaccine strain. Antigenic cartography which facilitates a quantitative interpretation and easy visualization of serological data was constructed based on HI results and further demonstrated the several antigenic groups among Egyptian H5N

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

    USGS Publications Warehouse

    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.

  9. An Impedance Aptasensor with Microfluidic Chips for Specific Detection of H5N1 Avian Influenza Virus

    PubMed Central

    Lum, Jacob; Wang, Ronghui; Hargis, Billy; Tung, Steve; Bottje, Walter; Lu, Huaguang; Li, Yanbin

    2015-01-01

    In this research a DNA aptamer, which was selected through SELEX (systematic evolution of ligands by exponential enrichment) to be specific against the H5N1 subtype of the avian influenza virus (AIV), was used as an alternative reagent to monoclonal antibodies in an impedance biosensor utilizing a microfluidics flow cell and an interdigitated microelectrode for the specific detection of H5N1 AIV. The gold surface of the interdigitated microelectrode embedded in a microfluidics flow cell was modified using streptavidin. The biotinylated aptamer against H5N1 was then immobilized on the electrode surface using biotin–streptavidin binding. The target virus was captured on the microelectrode surface, causing an increase in impedance magnitude. The aptasensor had a detection time of 30 min with a detection limit of 0.0128 hemagglutinin units (HAU). Scanning electron microscopy confirmed the binding of the target virus onto the electrode surface. The DNA aptamer was specific to H5N1 and had no cross-reaction to other subtypes of AIV (e.g., H1N1, H2N2, H7N2). The newly developed aptasensor offers a portable, rapid, low-cost alternative to current methods with the same sensitivity and specificity. PMID:26230699

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

    PubMed

    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.

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

    PubMed

    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.

  12. Antigenic analysis of highly pathogenic avian influenza virus H5N1 sublineages co-circulating in Egypt.

    PubMed

    Watanabe, Yohei; Ibrahim, Madiha S; Ellakany, Hany F; Kawashita, Norihito; Daidoji, Tomo; Takagi, Tatsuya; Yasunaga, Teruo; Nakaya, Takaaki; Ikuta, Kazuyoshi

    2012-10-01

    Highly pathogenic avian influenza virus H5N1 has spread across Eurasia and Africa, and outbreaks are now endemic in several countries, including Indonesia, Vietnam and Egypt. Continuous circulation of H5N1 virus in Egypt, from a single infected source, has led to significant genetic diversification with phylogenetically separable sublineages, providing an opportunity to study the impact of genetic evolution on viral phenotypic variation. In this study, we analysed the phylogeny of H5 haemagglutinin (HA) genes in influenza viruses isolated in Egypt from 2006 to 2011 and investigated the effect of conserved amino acid mutations in the HA genes in each of the sublineages on their antigenicity. The analysis showed that viruses in at least four sublineages still persisted in poultry in Egypt as of 2011. Using reverse genetics to generate HA-reassortment viruses with specific HA mutations, we found antigenic drift in the HA in two influenza virus sublineages, compared with the other currently co-circulating influenza virus sublineages in Egypt. Moreover, the two sublineages with significant antigenic drift were antigenically distinguishable. Our findings suggested that phylogenetically divergent H5N1 viruses, which were not antigenically cross-reactive, were co-circulating in Egypt, indicating that there was a problem in using a single influenza virus strain as seed virus to produce influenza virus vaccine in Egypt and providing data for designing more efficacious control strategies in H5N1-endemic areas.

  13. Assessing the risk of highly pathogenic avian influenza H5N1 transmission through poultry movements in Bali, Indonesia.

    PubMed

    Roche, Sharon E; Cogger, Naomi; Garner, M Graeme; Putra, Anak Agung Gde; Toribio, Jenny-Ann L M L

    2014-03-01

    Indonesia continues to report the highest number of human and poultry cases of highly pathogenic avian influenza H5N1. The disease is considered to be endemic on the island of Bali. Live bird markets are integral in the poultry supply chain on Bali and are important, nutritionally and culturally, for the rural and urban human populations. Due to the lack of biosecurity practiced along the supply chain from producer to live bird markets, there is a need to understand the risks associated with the spread of H5N1 through live bird movements for effective control. Resources to control H5N1 in Indonesia are very limited and cost effective strategies are needed. We assessed the probability a live bird market is infected through live poultry movements and assessed the effects of implementing two simple and low cost control measures on this risk. Results suggest there is a high risk a live bird market is infected (0.78), and risk mitigation strategies such as detecting and removing infected poultry from markets reduce this risk somewhat (range 0.67-0.76). The study demonstrates the key role live poultry movements play in transmitting H5N1 and the need to implement a variety of control measures to reduce disease spread.

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

    PubMed Central

    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

    2015-01-01

    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. PMID:26635249

  15. Genetic characterization of an H5N1 avian influenza virus from a vaccinated duck flock in Vietnam.

    PubMed

    Bui, Vuong Nghia; Ogawa, Haruko; Trinh, Dai Quang; Nguyen, Tham Hong Thi; Pham, Nga Thi; Truong, Duc Anh; Bui, Anh Ngoc; Runstadler, Jonathan; Imai, Kunitoshi; Nguyen, Khong Viet

    2014-10-01

    This study reports the genetic characterization of a highly pathogenic avian influenza virus subtype H5N1 isolated from a moribund domestic duck in central Vietnam during 2012. In the moribund duck's flock, within 6 days after vaccination with a commercial H5N1 vaccine (Re-5) to 59-day-old birds, 120 out of 2,000 ducks died. Genetic analysis revealed a substantial number of mutations in the HA gene of the isolate in comparison with the vaccine strains, Re-1 and Re-5. Similar mutations were also found in selected Vietnamese H5N1 strains isolated since 2009. Mutations in the HA gene involved positions at antigenic sites associated with antibody binding and also neutralizing epitopes, with some of the mutations resulting in the modification of N-linked glycosylation of the HA. Those mutations may be related to the escape of virus from antibody binding and the infection of poultry, interpretations which may be confirmed through a reverse genetics approach. The virus also carried an amino acid substitution in the M2, which conferred a reduced susceptibility to amantadine, but no neuraminidase inhibitor resistance markers were found in the viral NA gene. Additional information including vaccination history in the farm and the surrounding area is needed to fully understand the background of this outbreak. Such understanding and expanded monitoring of the H5N1 influenza viruses circulating in Vietnam is an urgent need to provide updated information to improve effective vaccine strain selection and vaccination protocols, aiding disease control, and biosecurity to prevent H5N1 infection in both poultry and humans.

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

    PubMed

    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.

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

    PubMed Central

    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

    2016-01-01

    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. PMID:27097026

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

    PubMed

    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.

  19. Implications of global and regional patterns of highly pathogenic avian influenza virus H5N1 clades for risk management.

    PubMed

    Pfeiffer, Dirk U; Otte, Martin J; Roland-Holst, David; Inui, Ken; Nguyen, Tung; Zilberman, David

    2011-12-01

    This paper analyses the publicly available data on the distribution and evolution of highly pathogenic avian influenza virus (HPAIV) H5N1 clades, whilst acknowledging the biases resulting from the non-random selection of isolates for gene sequencing. The data indicate molecular heterogeneity in the global distribution of HPAIV H5N1, in particular in different parts of East and Southeast Asia. Analysis of the temporal pattern of haemagglutinin clade data shows a progression from clade 0 (the 'dominant' clade between 1996 and 2002) to clade 1 (2003-2005) and then to clade 2.3.4 (2005 onwards). This process continuously produces variants, depending on the frequency of virus multiplication in the host population, which is influenced by geographical variation in poultry density, poultry production systems and also HPAI risk management measures such as vaccination. Increased multilateral collaboration needs to focus on developing enhanced disease surveillance and control targeted at evolutionary 'hotspots'.

  20. Efficacy of orally administered T-705 on lethal avian influenza A (H5N1) virus infections in mice.

    PubMed

    Sidwell, Robert W; Barnard, Dale L; Day, Craig W; Smee, Donald F; Bailey, Kevin W; Wong, Min-Hui; Morrey, John D; Furuta, Yousuke

    2007-03-01

    T-705 (6-fluoro-3-hydroxy-2-pyrazinecarboxamide) was inhibitory to four strains of avian H5N1 influenza virus in MDCK cells, with the 90% effective concentrations ranging from 1.3 to 7.7 microM, as determined by a virus yield reduction assay. The efficacy was less than that exerted by oseltamivir carboxylate or zanamivir but was greater than that exerted by ribavirin. Experiments with mice lethally infected with influenza A/Duck/MN/1525/81 (H5N1) virus showed that T-705 administered per os once, twice, or four times daily for 5 days beginning 1 h after virus exposure was highly inhibitory to the infection. Dosages from 30 to 300 mg/kg of body weight/day were well tolerated; each prevented death, lessened the decline of arterial oxygen saturation (SaO(2)), and inhibited lung consolidation and lung virus titers. Dosages from 30 to 300 mg/kg/day administered once or twice daily also significantly prevented the death of the mice. Oseltamivir (20 mg/kg/day), administered per os twice daily for 5 days, was tested in parallel in two experiments; it was only weakly effective against the infection. The four-times-daily T-705 treatments at 300 mg/kg/day could be delayed until 96 h after virus exposure and still significantly inhibit the infection. Single T-705 treatments administered up to 60 h after virus exposure also prevented death and the decline of SaO(2). Characterization of the pathogenesis of the duck influenza H5N1 virus used in these studies was undertaken; although the virus was highly pathogenic to mice, it was less neurotropic than has been described for clinical isolates of the H5N1 virus. These data indicate that T-705 may be useful for the treatment of avian influenza virus infections.

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

    PubMed

    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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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, ...

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

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

    2007-12-08

    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.

  6. DC-SIGN mediates avian H5N1 influenza virus infection in cis and in trans

    SciTech Connect

    Wang, S.-F.; Huang, Jason C.; Lee, Y.-M.; Liu, S.-J.; Chan, Yu-Jiun; Chau, Y.-P.; Chong, P.; Chen, Y.-M.A.

    2008-09-05

    DC-SIGN, a C-type lectin receptor expressed in dendritic cells (DCs), has been identified as a receptor for human immunodeficiency virus type 1, hepatitis C virus, Ebola virus, cytomegalovirus, dengue virus, and the SARS coronavirus. We used H5N1 pseudotyped and reverse-genetics (RG) virus particles to study their ability to bind with DC-SIGN. Electronic microscopy and functional assay results indicate that pseudotyped viruses containing both HA and NA proteins express hemagglutination and are capable of infecting cells expressing {alpha}-2,3-linked sialic acid receptors. Results from a capture assay show that DC-SIGN-expressing cells (including B-THP-1/DC-SIGN and T-THP-1/DC-SIGN) and peripheral blood dendritic cells are capable of transferring H5N1 pseudotyped and RG virus particles to target cells; this action can be blocked by anti-DC-SIGN monoclonal antibodies. In summary, (a) DC-SIGN acts as a capture or attachment molecule for avian H5N1 virus, and (b) DC-SIGN mediates infections in cis and in trans.

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

    PubMed

    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.

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

    PubMed

    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

  9. Host immune responses of ducks infected with H5N1 highly pathogenic avian influenza viruses of different pathogenicities.

    PubMed

    Wei, Liangmeng; Jiao, Peirong; Song, Yafen; Cao, Lan; Yuan, Runyu; Gong, Lang; Cui, Jin; Zhang, Shuo; Qi, Wenbao; Yang, Su; Liao, Ming

    2013-10-25

    Our previous studies have illustrated three strains of duck-origin H5N1 highly pathogenic avian influenza viruses (HPAIVs) had varying levels of pathogenicity in ducks (Sun et al., 2011). However, the host immune response of ducks infected with those of H5N1 HPAIVs was unclear. Here, we compared viral distribution and mRNA expression of immune-related genes in ducks following infection with the two HPAIV (A/Duck/Guangdong/212/2004, DK212 and A/Duck/Guangdong/383/2008, DK383). DK383 could replicate in the tested tissue of ducks (brain, spleen, lungs, cloacal bursa, kidney, and pancreas) more rapid and efficiently than DK212 at 1 and 2 days post-inoculation. Quantitative real-time PCR analysis showed that the expression levels of TLR3, IL-6, IL-8, and MHC class II in brains were higher than those of respective genes in lungs during the early stage of post infection. Furthermore, the expression levels of IL-6 and IL-8 in the brain of ducks following infection with DK383 were remarkably higher than those of ducks infected with DK212, respectively. Our results suggest that the shift in the H5N1 HPAIVs to increased virulence in ducks may be associated with efficient and rapid replication of the virus, accompanied by early destruction of host immune responses. These data are helpful to understand the underlying mechanism of the different outcome of H5N1 HPAIVs infection in ducks.

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

    PubMed

    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.

  11. The spread of highly pathogenic avian influenza (subtype H5N1) clades in Bangladesh, 2010 and 2011.

    PubMed

    Osmani, Muzaffar G; Ward, Michael P; Giasuddin, Md; Islam, Md Rafiqul; Kalam, Abul

    2014-04-01

    Since the global spread of highly pathogenic avian influenza H5N1 during 2005-2006, control programs have been successfully implemented in most affected countries. HPAI H5N1 was first reported in Bangladesh in 2007, and since then 546 outbreaks have been reported to the OIE. The disease has apparently become endemic in Bangladesh. Spatio-temporal information on 177 outbreaks of HPAI H5N1 occurring between February 2010 and April 2011 in Bangladesh, and 37 of these outbreaks in which isolated H5N1 viruses were phylogenetically characterized to clade, were analyzed. Three clades were identified, 2.2 (21 cases), 2.3.4 (2 cases) and 2.3.2.1 (14 cases). Clade 2.2 was identified throughout the time period and was widely distributed in a southeast-northwest orientation. Clade 2.3.2.1 appeared later and was generally confined to central Bangladesh in a north-south orientation. Based on a direction test, clade 2.2 viruses spread in a southeast-to-northwest direction, whereas clade 2.3.2.1 spread west-to-east. The magnitude of spread of clade 2.3.2.1 was greater relative to clade 2.2 (angular concentration 0.2765 versus 0.1860). In both cases, the first outbreak(s) were identified as early outliers, but in addition, early outbreaks (one each) of clade 2.2 were also identified in central Bangladesh and in northwest Bangladesh, a considerable distance apart. The spread of highly pathogenic avian influenza H5N1 in Bangladesh is characterized by reported long-distance translocation events. This poses a challenge to disease control efforts. Increased enforcement of biosecurity and stronger control of movements between affected farms and susceptible farms, and better surveillance and reporting, is needed. Although the movement of poultry and equipment appears to be a more likely explanation for the patterns identified, the relative contribution of trade and the market chain versus wild birds in spreading the disease needs further investigation.

  12. Environmental sampling for avian influenza virus A (H5N1) in live-bird markets, Indonesia.

    PubMed

    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.

  13. Factors Associated with the Emergence of Highly Pathogenic Avian Influenza A (H5N1) Poultry Outbreaks in China: Evidence from an Epidemiological Investigation in Ningxia, 2012.

    PubMed

    Liu, H; Zhou, X; Zhao, Y; Zheng, D; Wang, J; Wang, X; Castellan, D; Huang, B; Wang, Z; Soares Magalhães, R J

    2015-10-30

    In April 2012, highly pathogenic avian influenza virus of the H5N1 subtype (HPAIV H5N1) emerged in poultry layers in Ningxia. A retrospective case-control study was conducted to identify possible risk factors associated with the emergence of H5N1 infection and describe and quantify the spatial variation in H5N1 infection. A multivariable logistic regression model was used to identify risk factors significantly associated with the presence of infection; residual spatial variation in H5N1 risk unaccounted by the factors included in the multivariable model was investigated using a semivariogram. Our results indicate that HPAIV H5N1-infected farms were three times more likely to improperly dispose farm waste [adjusted OR = 0.37; 95% CI: 0.12-0.82] and five times more likely to have had visitors in their farm within the past month [adjusted OR = 5.47; 95% CI: 1.97-15.64] compared to H5N1-non-infected farms. The variables included in the final multivariable model accounted only 20% for the spatial clustering of H5N1 infection. The average size of a H5N1 cluster was 660 m. Bio-exclusion practices should be strengthened on poultry farms to prevent further emergence of H5N1 infection. For future poultry depopulation, operations should consider H5N1 disease clusters to be as large as 700 m.

  14. Variable regulation of chicken embryo fibroblasts gene expression by H5N1 avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic avian influenza viruses (HPAIVs) cause severe clinical disease associated with high mortality in chickens and other gallinaceous species. However, the mechanism by which different strains of AIV overcome host response is still not clear. In the present study, differences in early t...

  15. Four different sublineages of highly pathogenic avian influenza H5N1 introduced in Hungary in 2006-2007.

    PubMed

    Szeleczky, Zsófia; Dán, Adám; Ursu, Krisztina; Ivanics, Eva; Kiss, István; Erdélyi, Károly; Belák, Sándor; Muller, Claude P; Brown, Ian H; Bálint, Adám

    2009-10-20

    Highly pathogenic avian influenza (HPAI) H5N1 viruses were introduced to Hungary during 2006-2007 in three separate waves. This study aimed at determining the full-length genomic coding regions of the index strains from these epizootics in order to: (i) understand the phylogenetic relationship to other European H5N1 isolates, (ii) elucidate the possible connection between the different outbreaks and (iii) determine the putative origin and way of introduction of the different virus variants. Molecular analysis of the HA gene of Hungarian HPAI isolates obtained from wild birds during the first introduction revealed two groups designated Hungarian1 (HUN1) and Hungarian2 (HUN2) within sublineage 2.2B and clade 2.2.1, respectively. Sequencing the whole coding region of the two index viruses A/mute swan/Hungary/3472/2006 and A/mute swan/4571/Hungary/2006 suggests the role of wild birds in the introduction of HUN1 and HUN2 viruses: the most similar isolates to HUN1 and HUN2 group were found in wild avian species in Croatia and Slovakia, respectively. The second introduction of HPAI H5N1 led to the largest epizootic in domestic waterfowl in Europe. The index strain of the epizootic A/goose/Hungary/14756/2006 clustered to sublineage 2.2.A1 forming the Hungarian3 (HUN3) group. A common ancestry of HUN3 isolates with Bavarian strains is suggested as the most likely scenario of origin. Hungarian4 (HUN4) viruses isolated from the third introduction clustered with isolate A/turkey/United Kingdom/750/2007 forming a sublineage 2.2.A2. The origin and way of introduction of HUN4 viruses is still obscure, thus further genetic, phylogenetic, ecological and epidemiological data are required in order to elucidate it.

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

    PubMed Central

    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). PMID:27608035

  17. Development of reverse transcription recombinase polymerase amplification assay for avian influenza H5N1 HA gene detection.

    PubMed

    Yehia, Nahed; Arafa, Abdel-Satar; Abd El Wahed, Ahmed; El-Sanousi, Ahmed A; Weidmann, Manfred; Shalaby, Mohamed A

    2015-10-01

    The 2006 outbreaks of H5N1 avian influenza in Egypt interrupted poultry production and caused staggering economic damage. In addition, H5N1 avian influenza viruses represent a significant threat to public health. Therefore, the rapid detection of H5 viruses is very important in order to control the disease. In this study, a qualitative reverse transcription recombinase polymerase amplification (RT-RPA) assay for the detection of hemagglutinin gene of H5 subtype influenza viruses was developed. The results were compared to the real-time reverse transcription polymerase chain reaction (RT-PCR). An in vitro transcribed RNA standard of 970 nucleotides of the hemagglutinin gene was developed and used to determine the assay sensitivity. The developed H5 RT-RPA assay was able to detect one RNA molecule within 7 min, while in real-time RT-PCR, at least 90 min was required. H5 RT-RPA assay did not detect nucleic acid extracted from H5 negative samples or from other pathogens producing respiratory manifestation in poultry. The clinical performance of the H5 RT-RPA assay was tested in 30 samples collected between 2014 and 2015; the sensitivity of H5 RT-RPA and real-time RT-PCR was 100%. In conclusion, H5 RT-RPA was faster than real-time RT-PCR and easily operable in a portable device. Moreover, it had an equivalent sensitivity and specificity.

  18. The multigenic nature of the differences in pathogenicity of H5N1 highly pathogenic avian influenza viruses in domestic ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Eurasian H5N1 highly pathogenic avian influenza (HPAI) viruses have evolved into many genetic lineages. The divergent strains that have arisen express distinct pathobiological features and increased virulence for many bird species including domestic waterfowl. The pathogenicity of H5N1 HPAI vi...

  19. Effect of age on pathogenesis and innate immune responses in Pekin ducks infected with different H5N1 highly pathogenic avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pathogenicity of H5N1 highly pathogenic avian influenza (HPAI) viruses in domestic ducks varies between different viruses and is affected by the age of the ducks, with younger ducks presenting more severe disease. In order to better understand the pathobiology of H5N1 HPAI in ducks, including t...

  20. Role of immune-related host gene responses in the pathobiology of H5N1 highly pathogenic avian influenza in ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Asian highly pathogenic avian influenza (HPAI) H5N1 viruses have changed from producing mild respiratory infections in ducks to some strains causing severe disease and mortality. In this study we examined host response to infection with HPAI H5N1 viruses in ducks. With the use of a whole genom...

  1. Use of genomic interspecies microarray hybridization to detect differentially expressed genes associated with H5N1 avian influenza virus infections in ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Asian H5N1 highly pathogenic avian influenza (HPAI) viruses have changed from producing mild respiratory infections in ducks, to some strains producing severe disease and mortality. The objective of this study was to examine the differences in host response to infection with H5N1 HPAI viruses w...

  2. Variability in pathobiology of South Korean H5N1 high-pathogenicity avian influenza virus infection for 5 species of migratory waterfowl

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The biological outcome of H5N1 high pathogenicity avian influenza (HPAI) virus infection in wild waterfowl is poorly understood. This study examined infectivity and pathobiology of A/chicken/Korea/IS/06 (H5N1) HPAI virus infection in Mute swans (Cygnus olor), Greylag geese (Anser anser), Ruddy Sheld...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. Efficacy of commercial vaccines in protecting chickens and ducks against H5N1 highly pathogenic avian influenza viruses from Vietnam

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic (HP) H5N1 avian influenza (AI) viruses continue to circulate in Asia and have spread to other regions of the world. Though attempts at eradication of the viruses during various outbreaks have been successful for short periods of time, new strains of H5N1 viruses continue to emerge...

  5. Suboptimal protection against H5N1 highly pathogenic avian influenza viruses from Vietnam in ducks vaccinated with commercial poultry vaccines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic (HP) H5N1 avian influenza (AI) viruses continue to circulate in Asia and other regions of the world. Vaccination is used as part of H5N1 HPAI control programs in many countries; however, eradication of the disease has not been possible due to the emergence and spread of new viruses...

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

    PubMed

    Haider, N; Sturm-Ramirez, K; Khan, S U; Rahman, M Z; Sarkar, S; Poh, M K; Shivaprasad, H L; Kalam, M A; Paul, S K; Karmakar, P C; Balish, A; Chakraborty, A; Mamun, A A; Mikolon, A B; Davis, C T; Rahman, M; Donis, R O; Heffelfinger, J D; Luby, S P; Zeidner, N

    2017-02-01

    Mortality in ducks and geese caused by highly pathogenic avian influenza A(H5N1) infection had not been previously identified in Bangladesh. In June-July 2011, we investigated mortality in ducks, geese and chickens with suspected H5N1 infection in a north-eastern district of the country to identify the aetiologic agent and extent of the outbreak and identify possible associated human infections. We surveyed households and farms with affected poultry flocks in six villages in Netrokona district and collected cloacal and oropharyngeal swabs from sick birds and tissue samples from dead poultry. We conducted 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 influenza virus infection. In the six villages, among the 240 surveyed households and 11 small-scale farms, 61% (1789/2930) of chickens, 47% (4816/10 184) of ducks and 73% (358/493) of geese died within 14 days preceding the investigation. Of 70 sick poultry swabbed, 80% (56/70) had detectable RNA for influenza A/H5, including 89% (49/55) of ducks, 40% (2/5) of geese and 50% (5/10) of chickens. We isolated virus from six of 25 samples; sequence analysis of the hemagglutinin and neuraminidase gene of these six isolates indicated clade 2.3.2.1a of H5N1 virus. Histopathological changes 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. The recently introduced H5N1 clade 2.3.2.1a virus caused unusually high mortality in ducks and geese. Heightened surveillance in poultry is warranted to guide appropriate

  7. Antigenic characterization of H5N1 highly pathogenic avian influenza viruses isolated from poultry in India, 2006-2015.

    PubMed

    Bhat, Sudipta; Nagarajan, Shanmugasundaram; Kumar, Manoj; Murugkar, Harshad V; Kalaiyarasu, Semmannan; Venkatesh, Govindarajulu; Tosh, Chakradhar

    2017-02-01

    Highly pathogenic avian influenza (HPAI) is a major health concern worldwide. In this study, we focused on antigenic analysis of HPAI H5N1 viruses isolated from poultry in India between 2006 and 2015 comprising 25 isolates from four phylogenetic clades 2.2 (1 isolate), 2.2.2.1 (1 isolate), 2.3.2.1a (17 isolates) and 2.3.2.1c (6 isolates). Seven H5N1 isolates from all four clades were selected for production of chicken antiserum, and antigenic analysis was carried out by hemagglutination inhibition (HI) assay. HI data indicated antigenic divergence (6-21 fold reduction in cross-reactivity) between the two recently emerged clades 2.3.2.1a and 2.3.2.1c. These two clades are highly divergent (21-128 fold reduction in HI titre) from the earlier clades 2.2 /2.2.2.1 isolated in India. However, a maximum of 2-fold and 4-fold reduction in cross-reactivity was observed within the isolates of homologous clades 2.3.2.1c and 2.3.2.1a, respectively. The molecular basis of inter-clade antigenic divergence was examined in the haemagglutinin (HA) antigenic sites of the H5N1 virus. Amino acid changes at 8 HA antigenic sites were observed between clades 2.3.2.1a and 2.3.2.1c, whereas 20-23 substitutions were observed between clades 2.3.2.1a/2.3.2.1c and 2.2/2.2.2.1. Therefore, a systematic analysis of antigenic drift of the contemporary field isolates is a pre-requisite for determining the suitable strain(s) for vaccine candidature.

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

    PubMed

    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. Preventable H5N1 avian influenza epidemics in the British poultry industry network exhibit characteristic scales.

    PubMed

    Jonkers, A R T; Sharkey, K J; Christley, R M

    2010-04-06

    Epidemics are frequently simulated on redundantly wired contact networks, which have many more links between sites than are minimally required to connect all. Consequently, the modelled pathogen can travel numerous alternative routes, complicating effective containment strategies. These networks have moreover been found to exhibit 'scale-free' properties and percolation, suggesting resilience to damage. However, realistic H5N1 avian influenza transmission probabilities and containment strategies, here modelled on the British poultry industry network, show that infection dynamics can additionally express characteristic scales. These system-preferred scales constitute small areas within an observed power law distribution that exhibit a lesser slope than the power law itself, indicating a slightly increased relative likelihood. These characteristic scales are here produced by a network-pervading intranet of so-called hotspot sites that propagate large epidemics below the percolation threshold. This intranet is, however, extremely vulnerable; targeted inoculation of a mere 3-6% (depending on incorporated biosecurity measures) of the British poultry industry network prevents large and moderate H5N1 outbreaks completely, offering an order of magnitude improvement over previously advocated strategies affecting the most highly connected 'hub' sites. In other words, hotspots and hubs are separate functional entities that do not necessarily coincide, and hotspots can make more effective inoculation targets. Given the ubiquity and relevance of networks (epidemics, Internet, power grids, protein interaction), recognition of this spreading regime elsewhere would suggest a similar disproportionate sensitivity to such surgical interventions.

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

    PubMed Central

    Hagag, Ibrahim Thabet; Mansour, Shimaa M. G.; Zhang, Zerui; Ali, Ahmed A. H.; Ismaiel, El-Bakry M.; Salama, Ali A.; Cardona, Carol J.; Collins, James; Xing, Zheng

    2015-01-01

    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 of the HPAIVH5N

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

    PubMed

    Hagag, Ibrahim Thabet; Mansour, Shimaa M G; Zhang, Zerui; Ali, Ahmed A H; Ismaiel, El-Bakry M; Salama, Ali A; Cardona, Carol J; Collins, James; Xing, Zheng

    2015-01-01

    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 of the HPAIVH5N

  12. Protective Efficacy of Recombinant Turkey Herpes Virus (rHVT-H5) and Inactivated H5N1 Vaccines in Commercial Mulard Ducks against the Highly Pathogenic Avian Influenza (HPAI) H5N1 Clade 2.2.1 Virus

    PubMed Central

    Kilany, Walid H.; Safwat, Marwa; Mohammed, Samy M.; Salim, Abdullah; Fasina, Folorunso Oludayo; Fasanmi, Olubunmi G.; Shalaby, Azhar G.; Dauphin, Gwenaelle; Hassan, Mohammed K.; Lubroth, Juan; Jobre, Yilma M.

    2016-01-01

    In Egypt, ducks kept for commercial purposes constitute the second highest poultry population, at 150 million ducks/year. Hence, ducks play an important role in the introduction and transmission of avian influenza (AI) in the Egyptian poultry population. Attempts to control outbreaks include the use of vaccines, which have varying levels of efficacy and failure. To date, the effects of vaccine efficacy has rarely been determined in ducks. In this study, we evaluated the protective efficacy of a live recombinant vector vaccine based on a turkey Herpes Virus (HVT) expressing the H5 gene from a clade 2.2 H5N1 HPAIV strain (A/Swan/Hungary/499/2006) (rHVT-H5) and a bivalent inactivated H5N1 vaccine prepared from clade 2.2.1 and 2.2.1.1 H5N1 seeds in Mulard ducks. A 0.3ml/dose subcutaneous injection of rHVT-H5 vaccine was administered to one-day-old ducklings (D1) and another 0.5ml/dose subcutaneous injection of the inactivated MEFLUVAC was administered at 7 days (D7). Four separate challenge experiments were conducted at Days 21, 28, 35 and 42, in which all the vaccinated ducks were challenged with 106EID50/duck of H5N1 HPAI virus (A/chicken/Egypt/128s/2012(H5N1) (clade 2.2.1) via intranasal inoculation. Maternal-derived antibody regression and post-vaccination antibody immune responses were monitored weekly. Ducks vaccinated at 21, 28, 35 and 42 days with the rHVT-H5 and MEFLUVAC vaccines were protected against mortality (80%, 80%, 90% and 90%) and (50%, 70%, 80% and 90%) respectively, against challenges with the H5N1 HPAI virus. The amount of viral shedding and shedding rates were lower in the rHVT-H5 vaccine groups than in the MEFLUVAC groups only in the first two challenge experiments. However, the non-vaccinated groups shed significantly more of the virus than the vaccinated groups. Both rHVT-H5 and MEFLUVAC provide early protection, and rHVT-H5 vaccine in particular provides protection against HPAI challenge. PMID:27304069

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

    SciTech Connect

    Zhou, Fangye; Zhou, Jian; Ma, Lei; Song, Shaohui; Zhang, Xinwen; Li, Weidong; Jiang, Shude; Wang, Yue; Liao, Guoyang

    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. Safety test and field study of an inactivated oil-adjuvanted H5N1 avian influenza vaccine.

    PubMed

    Imamura, Takashi; Sakamoto, Ryuichi; Sasaki, Takashi; Kokumai, Norihide; Ohgitani, Toshiaki; Sawata, Akira; Lin, Zhifeng; Sakaguchi, Masashi

    2010-11-01

    We previously reported the development of an inactivated oil-adjuvanted avian influenza vaccine using an apathogenic H5N1 strain of the same lineage as the Eurasian lineage viruses currently epidemic in Asia. In this study, we confirmed the safety and evaluated the efficacy of this vaccine in layer chicken farms by field trials. No problematic adverse reactions occurred in the safety test. In addition, no adverse effects were observed in the field trial, and the antibody titer exceeded a protective level (hemagglutination inhibition (HI) antibody titer of 16) at 3 weeks after a single injection. Based on the above findings, this vaccine was confirmed to be safe and induced a protective level of antibody titer with a single injection in the chickens at the farms.

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

    PubMed

    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.

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

    PubMed Central

    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. PMID:26398118

  17. Impact of Educational Intervention Concerning Awareness and Behaviors Relating to Avian Influenza (H5N1) in a High-Risk Population in Vietnam

    PubMed Central

    Manabe, Toshie; Thuy, Pham Thi Phuong; Can, Vu Van; Takasaki, Jin; Huyen, Dinh Thi Thanh; Chau, Nguyen Thi My; Shimbo, Takuro; Ha, Bui Thi Thu; Izumi, Shinyu; Hanh, Tran Thuy; Chau, Ngo Quy; Kudo, Koichiro

    2011-01-01

    Background Early initiation of treatment is essential for treatment of avian influenza A/H5N1 viral infection in humans, as the disease can lead to rapid development of severe pneumonia which can result in death. Contact with infected poultry is known to be a significant risk factor for contraction of H5N1 infection. However, handling and encountering poultry are a part of most peoples' daily lives, especially in rural communities in Vietnam where epidemic outbreaks among poultry have been continuously reported. Enhancing proper knowledge relating to H5N1 and to the importance of early initiation of treatment are crucial. The aim of this study was to develop an effective educational program to enhance awareness of H5N1 and motivate people to access to health care earlier when H5N1 infection is suspected or likely. Methodology and Principal Findings A study was conducted in two agricultural communities (intervention and control groups) in the Ninh Binh province in Vietnam, where epidemic outbreaks of avian influenza have recently occurred in birds. A unique educational intervention was developed and provided to the intervention group, and no intervention was provided to the control group. A knowledge, attitude and practice (KAP) survey was conducted in both groups with a face-to-face interview by trained local healthcare workers at time points before and after the educational intervention. KAP scores were compared between the different time points and between the groups. How educational intervention influenced awareness relating to H5N1 and accessibility of healthcare in the population was analyzed. The study indicated an increased awareness of H5N1 and increased reliance on local health care workers. Conclusions The novel educational program which was developed for this study impacted awareness of H5N1, and resulted in more people seeking early access to healthcare, and also resulted in earlier medical intervention for patients with H5N1 avian influenza infection

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

    PubMed Central

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

    PubMed

    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

  20. Global alert to avian influenza virus infection: From H5N1 to H7N9

    PubMed Central

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

    2013-01-01

    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. PMID:23916331

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

    PubMed

    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.

  2. Highly pathogenic avian influenza H5N1 virus induces cytokine dysregulation with suppressed maturation of chicken monocyte-derived dendritic cells.

    PubMed

    Kalaiyarasu, Semmannan; Kumar, Manoj; Senthil Kumar, Dhanapal; Bhatia, Sandeep; Dash, Sandeep Kumar; Bhat, Sushant; Khetan, Rohit K; Nagarajan, Shanmugasundaram

    2016-10-01

    One of the major causes of death in highly pathogenic avian influenza virus (HPAIV) infection in chickens is acute induction of pro-inflammatory cytokines (cytokine storm), which leads to severe pathology and acute mortality. DCs and respiratory tract macrophages are the major antigen presenting cells that are exposed to mucosal pathogens. We hypothesized that chicken DCs are a major target for induction of cytokine dysregulation by H5N1 HPAIV. It was found that infection of chicken peripheral blood monocyte-derived dendritic cells (chMoDCs) with H5N1 HPAIV produces high titers of progeny virus with more rounding and cytotoxicity than with H9N2 LPAIV. Expression of maturation markers (CD40, CD80 and CD83) was weaker in both H5N1 and H9N2 groups than in a LPS control group. INF-α, -β and -γ were significantly upregulated in the H5N1 group. Pro-inflammatory cytokines (IL-1β, TNF-α and IL-18) were highly upregulated in early mid (IL-1), and late (IL-6) phases of H5N1 virus infection. IL-8 (CXCLi2) mRNA expression was significantly stronger in the H5N1 group from 6 hr of infection. TLR3, 7, 15 and 21 were upregulated 24 hr after infection by H5N1 virus compared with H9N2 virus, with maximum expression of TLR 3 mRNA. Similarly, greater H5N1 virus-induced apoptotic cell death and cytotoxicity, as measured by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and lactate dehydrogenase assays, respectively, were found. Thus, both H5N1 and H9N2 viruses evade the host immune system by inducing impairment of chMoDCs maturation and enhancing cytokine dysregulation in H5N1 HPAIV-infected cells.

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

    PubMed

    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.

  4. Enhanced virulence of clade 2.3.2.1 highly pathogenic avian influenza A(H5N1) viruses in ferrets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. Avian influenza A (H5N1) infection with respiratory failure and meningoencephalitis in a Canadian traveller.

    PubMed

    Rajabali, Naheed; Lim, Thomas; Sokolowski, Colleen; Prevost, Jason D; Lee, Edward Z

    2015-01-01

    In an urban centre in Alberta, an otherwise healthy 28-year-old woman presented to hospital with pleuritic chest and abdominal pain after returning from Beijing, China. After several days, this was followed by headache, confusion and, ultimately, respiratory failure, coma and death. Microbiology yielded influenza A subtype H5N1 from various body sites and neuroimaging was consistent with meningoencephalitis. While H5N1 infections in humans have been reported in Asia since 1997, this is the first documented case of H5N1 influenza in the Western Hemisphere. The present case demonstrated the typical manifestation of H5N1 influenza but, for the first time, also confirmed previous suggestions from human and animal studies that H5N1 is neurotropic and can manifest with neurological symptoms and meningoencephalitis.

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

    PubMed

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

    2017-04-01

    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.

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

    USGS Publications Warehouse

    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.

    PubMed

    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. 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

    PubMed Central

    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 were asked to complete a questionnaire, and to provide blood samples. For evaluation of the use of protective measures, we developed a personal protective equipment (PPE)-score ranging between 0 and 9, where 9 corresponds to a consistent and complete use of PPE. Sera were tested by plaque neutralization (PN) and microneutralization (MN) assays. Reactive sera were reanalysed in the World Health Organization-Collaborating Centre (WHO-CC) using MN assay. Results Of the eligible personnel, consisting of firemen, government workers and veterinarians, 61% (97/154) participated in the study. Of those, 13% reported having always worn all PPE-devices during bird collection (PPE-score: 9). Adherence differed between firemen (mean PPE-score: 6.6) and government workers (mean PPE-score: 4.5; p = 0.006). The proportion of personnel always adherent to wearing PPE was lowest for masks (19%). Of the participants, 18% had received seasonal influenza vaccination prior to the outbreak. There were no reports of influenza-like illness. Five sera initially H5-reactive by PN assay were negative by WHO-CC confirmatory testing. Conclusion Gaps and variability in adherence demonstrate the risk of exposure to avian influenza under conditions of wild bird collection, and justify serological testing and regular training of task personnel. PMID:19835632

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

    PubMed

    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.

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

    PubMed

    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.

  12. The Landscape Epidemiology of Seasonal Clustering of Highly Pathogenic Avian Influenza (H5N1) in Domestic Poultry in Africa, Europe and Asia.

    PubMed

    Walsh, M G; Amstislavski, P; Greene, A; Haseeb, M A

    2016-06-16

    Highly pathogenic avian influenza subtype H5N1 (H5N1) has contributed to substantial economic loss for backyard and large-scale poultry farmers each year since 1997. While the distribution of domestic H5N1 outbreaks across Africa, Europe and Asia is extensive, those features of the landscape conferring greatest risk remain uncertain. Furthermore, the extent to which influential landscape features may vary by season has been inadequately described. The current investigation used World Organization for Animal Health surveillance data to (i) delineate areas at greatest risk of H5N1 epizootics among domestic poultry, (ii) identify those abiotic and biotic features of the landscape associated with outbreak risk and (iii) examine patterns of epizootic clustering by season. Inhomogeneous point process models were used to predict the intensity of H5N1 outbreaks and describe the spatial dependencies between them. During October through March, decreasing precipitation, increasing isothermality and the presence of H5N1 in wild birds were significantly associated with the increased risk of domestic H5N1 epizootics. Conversely, increasing precipitation and decreasing isothermality were associated with the increased risk during April through September. Increasing temperature during the coldest quarter, domestic poultry density and proximity to surface water were associated with the increased risk of domestic outbreaks throughout the year. Spatial dependencies between outbreaks appeared to vary seasonally, with substantial clustering at small and large scales identified during October through March even after accounting for inhomogeneity due to landscape factors. In contrast, during April to September, H5N1 outbreaks exhibited no clustering at small scale once accounting for landscape factors. This investigation has identified seasonal differences in risk and clustering patterns of H5N1 outbreaks in domestic poultry and may suggest strategies in high-risk areas with features

  13. Seroevidence for a High Prevalence of Subclinical Infection With Avian Influenza A(H5N1) Virus Among Workers in a Live-Poultry Market in Indonesia

    PubMed Central

    Shimizu, Kazufumi; Wulandari, Laksmi; Poetranto, Emmanuel D.; Setyoningrum, Retno A.; Yudhawati, Resti; Sholikhah, Amelia; Nastri, Aldise M.; Poetranto, Anna L.; Candra, Adithya Y. R.; Puruhito, Edith F.; Takahara, Yusuke; Yamagishi, Yoshiaki; Yamaoka, Masaoki; Hotta, Hak; Ustumi, Takako; Lusida, Maria I.; Soetjipto; Shimizu, Yohko K.; Soegiarto, Gatot; Mori, Yasuko

    2016-01-01

    Background. In Indonesia, highly pathogenic avian influenza A(H5N1) virus has become endemic in poultry and has caused sporadic deadly infections in human. Since 2012, we have conducted fixed-point surveillance of avian influenza viruses at a live-poultry market in East Java, Indonesia. In this study, we examined the seroprevalence of avian influenza A(H5N1) virus infection among market workers. Methods. Sera were collected from 101 workers in early 2014 and examined for antibody activity against avian A(H5N1) Eurasian lineage virus by a hemagglutination-inhibition (HI) assay. Results. By the HI assay, 84% of the sera tested positive for antibody activity against the avian virus. Further analysis revealed that the average HI titer in 2014 was 2.9-fold higher than in 2012 and that seroconversion occurred in 44% of paired sera (11 of 25) between 2012 and 2014. A medical history survey was performed in 2016; responses to questionnaires indicated that none of workers had had severe acute respiratory illness during 2013. Conclusions. This study provides evidence of a high prevalence of avian A(H5N1) virus infection in 2013 among workers at a live-poultry market. However, because no instances of hospitalizations were reported, we can conclude the virus did not manifest any clinical symptoms in workers. PMID:27923953

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

    PubMed

    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.

  15. Genetic characterization of clade 2.3.2.1 avian influenza A(H5N1) viruses, Indonesia, 2012.

    PubMed

    Dharmayanti, Ni Luh Putu Indi; Hartawan, Risza; Wibawa, Hendra; Balish, Amanda; Donis, Ruben; Davis, C Todd; Samaan, Gina

    2014-04-01

    After reports of unusually high mortality rates among ducks on farms in Java Island, Indonesia, in September 2012, influenza A(H5N1) viruses were detected and characterized. Sequence analyses revealed all genes clustered with contemporary clade 2.3.2.1 viruses, rather than enzootic clade 2.1.3 viruses, indicating the introduction of an exotic H5N1 clade into Indonesia.

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

    PubMed

    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.

  17. Risk factors and characteristics of H5N1 Highly Pathogenic Avian Influenza (HPAI) post-vaccination outbreaks.

    PubMed

    Henning, Joerg; Pfeiffer, Dirk U; Vu, Le Tri

    2009-01-01

    Highly pathogenic avian influenza (HPAI) virus H5N1 is now endemic in South-East Asia but HPAI control methods differ between countries. A widespread HPAI vaccination campaign that started at the end of 2005 in Viet Nam resulted in the cessation of poultry and human cases, but in 2006/2007 severe HPAI outbreaks re-emerged. In this study we investigated the pattern of this first post-vaccination epidemic in southern Viet Nam identifying a spatio-temporal cluster of outbreak occurrence and estimating spatially smoothed incidence rates of HPAI. Spatial risk factors associated with HPAI occurrence were identified. Medium-level poultry density resulted in an increased outbreak risk (Odds ratio (OR) = 5.4, 95% confidence interval (CI): 1.6-18.9) but also climate-vegetation factors played an important role: medium-level normalised difference vegetation indices during the rainy season from May to October were associated with higher risk of HPAI outbreaks (OR = 3.7, 95% CI: 1.7-8.1), probably because temporal flooding might have provided suitable conditions for the re-emergence of HPAI by expanding the virus distribution in the environment and by enlarging areas of possible contacts between domestic waterfowl and wild birds. On the other hand, several agricultural production factors, such as sweet potatoes yield, increased buffalo density, as well as increased electricity supply were associated with decreased risk of HPAI outbreaks. This illustrates that preventive control measures for HPAI should include a promotion of low-risk agricultural management practices as well as improvement of the infrastructure in village households. Improved HPAI vaccination efforts and coverage should focus on medium poultry density areas and on the pre-monsoon time period.

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

    NASA Astrophysics Data System (ADS)

    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. Quantitative assessment of a spatial multicriteria model for highly pathogenic avian influenza H5N1 in Thailand, and application in Cambodia

    PubMed Central

    Paul, Mathilde C.; Goutard, Flavie L.; Roulleau, Floriane; Holl, Davun; Thanapongtharm, Weerapong; Roger, François L.; Tran, Annelise

    2016-01-01

    The Highly Pathogenic Avian Influenza H5N1 (HPAI) virus is now considered endemic in several Asian countries. In Cambodia, the virus has been circulating in the poultry population since 2004, with a dramatic effect on farmers’ livelihoods and public health. In Thailand, surveillance and control are still important to prevent any new H5N1 incursion. Risk mapping can contribute effectively to disease surveillance and control systems, but is a very challenging task in the absence of reliable disease data. In this work, we used spatial multicriteria decision analysis (MCDA) to produce risk maps for HPAI H5N1 in poultry. We aimed to i) evaluate the performance of the MCDA approach to predict areas suitable for H5N1 based on a dataset from Thailand, comparing the predictive capacities of two sources of a priori knowledge (literature and experts), and ii) apply the best method to produce a risk map for H5N1 in poultry in Cambodia. Our results showed that the expert-based model had a very high predictive capacity in Thailand (AUC = 0.97). Applied in Cambodia, MCDA mapping made it possible to identify hotspots suitable for HPAI H5N1 in the Tonlé Sap watershed, around the cities of Battambang and Kampong Cham, and along the Vietnamese border. PMID:27489997

  20. Rapid detection of avian influenza virus H5N1 in chicken tracheal samples using an impedance aptasensor with gold nanoparticles for signal amplification.

    PubMed

    Karash, Sardar; Wang, Ronghui; Kelso, Lisa; Lu, Huaguang; Huang, Tony Jun; Li, Yanbin

    2016-10-01

    Highly pathogenic avian influenza virus H5N1 is a continuous threat to public health and poultry industry. The recurrence of the H5N1 led us to develop a robust, specific, and rapid detection method for the virus. In this study, an impedance aptasensor was developed for the virus detection using specific H5N1 aptamer and a gold interdigitated microelectrode. Streptavidin was immobilized on the microelectrode surface and biotin labeled H5N1 aptamer was bound to the immobilized streptavidin. The microelectrode was blocked with the polyethylene glycol and the bound aptamer captured the virus. The impedance change caused by the captured virus was measured using an impedance analyzer. To enhance impedance signal, a nanoparticle-based amplifier was designed and implemented by forming a network-like gold nanoparticles/H5N1-aptamer/thiocyanuric acid. The detection limit of the impedance aptasensor was 0.25 HAU for the pure virus and 1 HAU for the tracheal chicken swab samples spiked with the H5N1 virus. The detection time of aptasensor without employing the amplifier was less than an hour. The amplifier increased impedance by a 57-fold for the 1 HAU samples. Only negligible impedance change was observed for non-target viruses such as H5N2, H5N3, H7N2, H1N1, and H2N2. This aptasensor provides a foundation for the development of a portable aptasensor instrument.

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

    PubMed Central

    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. PMID:27507581

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

    PubMed

    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.

  3. Isolation and characterization of avian influenza viruses, including highly pathogenic H5N1, from poultry in live bird markets in Hanoi, Vietnam, in 2001.

    PubMed

    Nguyen, Doan C; Uyeki, Timothy M; Jadhao, Samadhan; Maines, Taronna; Shaw, Michael; Matsuoka, Yumiko; Smith, Catherine; Rowe, Thomas; Lu, Xiuhua; Hall, Henrietta; Xu, Xiyan; Balish, Amanda; Klimov, Alexander; Tumpey, Terrence M; Swayne, David E; Huynh, Lien P T; Nghiem, Ha K; Nguyen, Hanh H T; Hoang, Long T; Cox, Nancy J; Katz, Jacqueline M

    2005-04-01

    Since 1997, outbreaks of highly pathogenic (HP) H5N1 and circulation of H9N2 viruses among domestic poultry in Asia have posed a threat to public health. To better understand the extent of transmission of avian influenza viruses (AIV) to humans in Asia, we conducted a cross-sectional virologic study in live bird markets (LBM) in Hanoi, Vietnam, in October 2001. Specimens from 189 birds and 18 environmental samples were collected at 10 LBM. Four influenza A viruses of the H4N6 (n = 1), H5N2 (n = 1), and H9N3 (n = 2) subtypes were isolated from healthy ducks for an isolation frequency of over 30% from this species. Two H5N1 viruses were isolated from healthy geese. The hemagglutinin (HA) genes of these H5N1 viruses possessed multiple basic amino acid motifs at the cleavage site, were HP for experimentally infected chickens, and were thus characterized as HP AIV. These HA genes shared high amino acid identities with genes of other H5N1 viruses isolated in Asia during this period, but they were genetically distinct from those of H5N1 viruses isolated from poultry and humans in Vietnam during the early 2004 outbreaks. These viruses were not highly virulent for experimentally infected ducks, mice, or ferrets. These results establish that HP H5N1 viruses with properties similar to viruses isolated in Hong Kong and mainland China circulated in Vietnam as early as 2001, suggest a common source for H5N1 viruses circulating in these Asian countries, and provide a framework to better understand the recent widespread emergence of HP H5N1 viruses in Asia.

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

    PubMed

    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.

  5. An immunoassay-based reverse-transcription loop-mediated isothermal amplification assay for the rapid detection of avian influenza H5N1 virus viremia.

    PubMed

    Tang, Yi; Yu, Xu; Chen, Hao; Diao, Youxiang

    2016-12-15

    Avian influenza virus (AIV) subtype H5N1 attracts particular consideration because it is a continuous threat to animals and public health systems. The viremia caused by AIV H5N1 infection may increase the risk of blood-borne transmission between humans. Therefore, there is a need to rapidly evaluate and implement screening measures for AIV H5N1 viremia that allows for rapid response to this potentially pandemic threat. The present report describes an immunoassay-based reverse-transcription loop-mediated isothermal amplification (immuno-RT-LAMP) assay for the rapid detection of AIV H5N1 in whole blood samples. Using PCR tubes coated with an H5 subtype monoclonal antibody, AIV H5N1 virions were specifically captured from blood samples. After a thermal lysis step, the released viral N1 gene was exponentially amplified using RT-LAMP on either a real-time PCR instrument for quantitative analysis, or in a water bath system for endpoint analysis. The detection limit of the newly developed immuno-RT-LAMP assay was as low as 1.62×10(1) 50% embryo infectious dose/mL of virus in both regular samples and simulated viremia samples. There were no cross-reactions with non-H5N1 influenza viruses or other avian viruses. The reproducibility of the assay was confirmed using intra- and inter-assay tests with variability ranging from 1.05% to 3.37%. Our results indicate that immuno-RT-LAMP is a novel, effective point-of-care virus identification solution for the rapid diagnosis and monitoring of AIV H5N1 in blood samples.

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

    PubMed Central

    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 < .001). We observed no significant differences in the age and severity between sporadic/index and secondary H5N1 cases. The upper limit of the 95% confidence interval (CI) for R was 0.12 for H5N1 and 0.27 for 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

  7. Phylogenetic and pathogenic analyses of three H5N1 avian influenza viruses (clade 2.3.2.1) isolated from wild birds in Northeast China.

    PubMed

    Fan, Zhaobin; Ci, Yanpeng; Liu, Liling; Ma, Yixin; Jia, Ying; Wang, Deli; Guan, Yuntao; Tian, Guobin; Ma, Jianzhang; Li, Yanbing; Chen, Hualan

    2015-01-01

    From April to September 2012, periodic surveillance of avian influenza H5N1 viruses from different wild bird species was conducted in Northeast China. Three highly pathogenic avian influenza (HPAI) H5N1 viruses were isolated from a yellow-browed warbler, common shoveler, and mallard. To trace the genetic lineage of the isolates, nucleotide sequences of all eight gene segments were determined and phylogenetically analyzed. The data indicated that three viruses belonged to the same antigenic virus group: clade 2.3.2.1. To investigate the pathogenicity of these three viruses in different hosts, chickens, ducks, and mice were inoculated. The results showed that chickens were susceptible to each of the three HPAI H5N1 viruses, resulting in 100% mortality within 2-6 days after infection, whereas the three isolates exhibited distinctly different virulence in ducks and mice. The results of this study demonstrated that HPAI H5N1 viruses of clade 2.3.2.1 are still circulating in wild birds through overlapping migratory flyways. Therefore, continuous monitoring of H5N1 in both domestic and wild birds is necessary to prevent a potentially wider outbreak.

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

    PubMed

    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.

  9. Intranasal immunization with live recombinant Lactococcus lactis combined with heat-labile toxin B subunit protects chickens from highly pathogenic avian influenza H5N1 virus.

    PubMed

    Lei, Han; Peng, Xiaojue; Shu, Handing; Zhao, Daxian

    2015-01-01

    Development of safe and effective vaccines to prevent highly pathogenic avian influenza H5N1 virus infection is a challenging goal. Lactococcus lactis (L. lactis) is an ideal delivery vector for vaccine development, and it has been shown previously that oral immunization of encapsulated secretory L. lactis-hemagglutinin (HA) could provide complete protection against homologous H5N1 virus challenge in the mice model. While intranasal immunization is an appealing approach, it is now reported that secretory L. lactis-HA combined with mucosal adjuvant heat-labile toxin B subunit (LTB) could provide protective immunity in the chicken model. As compared to intranasal immunization with L. lactis-HA alone, L. lactis-HA combined with LTB (L. lactis-HA + LTB) could elicit robust neutralizing antibody responses and mucosal IgA responses, as well as strong cellular immune responses in the vaccinated chickens. Importantly, intranasal immunization with L. lactis-HA + LTB could provide 100% protection against H5N1 virus challenge. Taken together, these results suggest that intranasal immunization with L. lactis-HA + LTB can be considered as an effective approach for preventing and controlling infection of H5N1 virus in poultry during an avian influenza A/H5N1 pandemic.

  10. Variation in protection by seven inactivated H5 vaccine strains against eight H5N1 high pathogenicity avian influenza viruses in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    H5N1 high pathogenicity avian influenza virus (HPAIV) is an important pathogen for poultry. Vaccines have assisted in control for poultry, and for human pandemic preparedness. However the genetic diversity and rapid antigenic drifting of the field viruses have led to inadequate protection. This s...

  11. A highly pathogenic avian influenza virus H5N1 with 2009 pandemic H1N1 internal genes demonstrated increased replication and transmission in pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study investigated the pathogenicity and transmissibility of a reverse-genetics derived highly pathogenic avian influenza (HPAI) H5N1 influenza A virus (IAV), A/Iraq/775/06, and a reassortant virus comprised of the HA and NA from A/Iraq/775/06 and the internal genes of a 2009 pandemic H1N1, A/N...

  12. Expression of H5 hemagglutinin vaccine antigen in common duckweed (Lemna minor) protects against H5N1 high pathogenicity avian influenza virus challenge in immunized chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A synthetic hemagglutinin (HA) gene from the highly pathogenic avian influenza (HPAI) virus A/chicken/Indonesia/7/2003 (H5N1) (Indo/03) was expressed in aquatic plant Lemna minor (rLemna-HA). In Experiment 1, efficacy of rLemna-HA was tested on specific pathogen free (SPF) birds immunized with 0.2 ...

  13. Infectious and lethal doses of H5N1 highly pathogenic avian influenza virus for house sparrows (Passer domesticus) and rock pigeons (Columbia livia)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Terrestrial wild birds commonly associated with poultry farms have the potential to contribute to the spread of H5N1 highly pathogenic avian influenza virus within or between poultry facilities or between domesticated and wild bird populations. This potential, however, varies between species and is...

  14. Susceptibility of five migratory aquatic birds to H5N1 highly pathogenic avian influenza virus (A/Chicken/Korea/IS/06)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is not known which migratory aquatic species are important in spreading H5N1 highly pathogenic avian influenza (HPAI) viruses, and the pathobiology of infections by such viruses. The objective of this investigation was to assess the susceptibility of Mute swans (Cygnus olor), Greylag geese (Anse...

  15. Differences in pathogenicity of A/Duck/Vietnam/201/05 H5N1 highly pathogenic avian influenza virus reassortants in ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to understand which viral genes contribute to the high virulence of A/Dk/Vietnam/201/05 H5N1 highly pathogenic avian influenza (HPAI) virus in ducks, we used reverse genetics to generate single-gene reassortant viruses with genes from A/Ck/Indonesia/7/03, a virus that produces mild disease ...

  16. Phylogenetic and biological characterization of highly pathogenic H5N1 avian influenza viruses (Vietnam 2005) in chickens and ducks virus research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Analysis of Asian H5N1 avian influenza (AI) virus hemagglutinin (HA) genes shows a common origin, but the virus has evolved into at least three major clades (clades 0, 1, and 2) over the last 11 years. Previous reports of Vietnam viruses have documented predominantly clade 1 viruses. Unexpectedly,...

  17. Impact of vaccination on infection with Vietnam H5N1 high pathogenicity avian influenza virus in hens and the eggs they lay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High pathogenicity avian influenza virus (HPAIV) infections in chickens decrease egg production and eggs that are laid contain HPAIV. Vaccination once or twice was examined as a way to protect chickens from Vietnamese H5N1 HPAIV. Eighty-three percent of hens without vaccination died within 3 days ...

  18. PB1-F2 Attenuates Virulence of Highly Pathogenic Avian H5N1 Influenza Virus in Chickens

    PubMed Central

    Leymarie, Olivier; Embury-Hyatt, Carissa; Chevalier, Christophe; Jouneau, Luc; Moroldo, Marco; Da Costa, Bruno; Berhane, Yohannes; Delmas, Bernard

    2014-01-01

    Highly pathogenic avian influenza virus (HPAIV) is a permanent threat due to its capacity to cross species barriers and generate severe infections and high mortality in humans. Recent findings have highlighted the potential role of PB1-F2, a small accessory influenza protein, in the pathogenesis process mediated by HPAIV in mammals. In this study, using a recombinant H5N1 HPAIV (wt) and its PB1-F2-deleted mutant (ΔF2), we studied the effects of PB1-F2 in a chicken model. Unexpectedly, when using low inoculation dose we observed that the wt-infected chickens had a higher survival rate than the ΔF2-infected chickens, a feature that contrasts with what is usually observed in mammals. High inoculation dose had similar mortality rate for both viruses, and comparison of the bio-distribution of the two viruses indicated that the expression of PB1-F2 allows a better spreading of the virus within chicken embryos. Transcriptomic profiles of lungs and blood cells were characterized at two days post-infection in chickens inoculated with the wild type (wt) or the ΔF2 mutant viruses. In lungs, the expression of PB1-F2 during the infection induced pathways related to calcium signaling and repressed a large panel of immunological functions. In blood cells, PB1-F2 was associated with a gene signature specific for mitochondrial dysfunction and down-modulated leucocytes activation. Finally we compared the effect of PB1-F2 in lungs of chickens and mice. We identified that gene signature associated to tissue damages is a PB1-F2 feature shared by the two species; by contrast, the early inhibition of immune response mediated by PB1-F2 observed in chickens is not seen in mice. In summary, our data suggest that PB1-F2 expression deeply affect the immune response in chickens in a way that may attenuate pathogenicity at low infection dose, a feature differing from what was previously observed in mammal species. PMID:24959667

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

    PubMed

    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.

  20. 75 FR 69046 - Notice of Determination of the High Pathogenic Avian Influenza Subtype H5N1 Status of Czech...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-10

    ... importation of live birds, poultry carcasses, parts or products of poultry carcasses, and eggs (other than hatching eggs) of poultry, game birds, and other birds from the Czech Republic and Sweden presents a low... of the status of HPAI H5N1 in domestic and wild poultry in the Czech Republic and Sweden, in light...

  1. An impedance immunosensor based on low-cost microelectrodes and specific monoclonal antibodies for rapid detection of avian influenza virus H5N1 in chicken swabs.

    PubMed

    Lin, Jianhan; Wang, Ronghui; Jiao, Peirong; Li, Yuntao; Li, Yanbin; Liao, Min; Yu, Yude; Wang, Maohua

    2015-05-15

    Early screening of suspected cases is the key to control the spread of avian influenza (AI) H5N1. In our previous studies, an impedance biosensor with an interdigitated array microelectrode based biochip was developed and validated with pure AI H5 virus, but had limitations in cost and reliability of the biochip, specificity of the antibody against Asian in-field H5N1 virus and detection of H5N1 virus in real samples. The purpose of this study is to develop a low-cost impedance immunosensor for rapid detection of Asian in-field AI H5N1 virus in chicken swabs within 1h and validate it with the H5N1 virus. Specific monoclonal antibodies against AI H5N1 virus were developed by fusion of mouse myeloma cells with spleen cells isolated from an H5N1-virus-immunized mouse. Dot-ELISA analysis demonstrated that the developed antibodies had good affinity and specificity with the H5N1 virus. The microelectrodes were redesigned with compact size, fabricated using an improved wet-etching micro-fabrication process with a higher qualified production rate of 70-80%, and modified with the antibodies by the Protein A method. Equivalent circuit analysis indicated that electron transfer resistor was effective with the increase in impedance after capturing of the H5N1 viruses. Linear relationship between impedance change and logarithmic value of H5N1 virus at the concentrations from 2(-1) to 2(4) HAU/50 μl was found and the lower limit of detection was 2(-1) HAU/50 μl. No obvious interferences from non-target viruses such as H6N2, H9N2, Newcastle disease virus, and infectious bronchitis virus were found. Chicken swab tests showed that the impedance immunosensor had a comparable accuracy with real-time RT-PCR compared to viral isolation.

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

    PubMed Central

    Qu, Xiao; Ding, Longfei; Qin, Zhenqiao; Wu, Jianguo; Pan, Zishu

    2015-01-01

    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. PMID:25938456

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

    PubMed

    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.

  4. Evolutionary trajectories and diagnostic challenges of potentially zoonotic avian influenza viruses H5N1 and H9N2 co-circulating in Egypt.

    PubMed

    Naguib, Mahmoud M; Arafa, Abdel-Satar A; El-Kady, Magdy F; Selim, Abdullah A; Gunalan, Vithiagaran; Maurer-Stroh, Sebastian; Goller, Katja V; Hassan, Mohamed K; Beer, Martin; Abdelwhab, E M; Harder, Timm C

    2015-08-01

    In Egypt, since 2006, descendants of the highly pathogenic avian influenza virus (HP AIV) H5N1 of clade 2.2 continue to cause sharp losses in poultry production and seriously threaten public health. Potentially zoonotic H9N2 viruses established an endemic status in poultry in Egypt as well and co-circulate with HP AIV H5N1 rising concerns of reassortments between H9N2 and H5N1 viruses along with an increase of mixed infections of poultry. Nucleotide sequences of whole genomes of 15 different isolates (H5N1: 7; H9N2: 8), and of the hemagglutinin (HA) and neuraminidase (NA) encoding segments of nine further clinical samples (H5N1: 2; H9N2: 7) from 2013 and 2014 were generated and analysed. The HA of H5N1 viruses clustered with clade 2.2.1 while the H9 HA formed three distinguishable subgroups within cluster B viruses. BEAST analysis revealed that H9N2 viruses are likely present in Egypt since 2009. Several previously undescribed substituting mutations putatively associated with host tropism and virulence modulation were detected in different proteins of the analysed H9N2 and H5N1 viruses. Reassortment between HP AIV H5N1 and H9N2 is anticipated in Egypt, and timely detection of such events is of public health concern. As a rapid tool for detection of such reassortants discriminative SYBR-Green reverse transcription real-time PCR assays (SG-RT-qPCR), targeting the internal genes of the Egyptian H5N1 and H9N2 viruses were developed for the rapid screening of viral RNAs from both virus isolates and clinical samples. However, in accordance to Sanger sequencing, no reassortants were found by SG-RT-qPCR. Nevertheless, the complex epidemiology of avian influenza in poultry in Egypt will require sustained close observation. Further development and continuing adaptation of rapid and cost-effective screening assays such as the SG-RT-qPCR protocol developed here are at the basis of efforts for improvement the currently critical situation.

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

    PubMed

    Sha, Jianping; Dong, Wei; Liu, Shelan; Chen, Xiaowen; Zhao, Na; Luo, Mengyun; Dong, Yuanyuan; Zhang, Zhiruo

    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 (<15 years old), as well as the childhood cluster cases of the two viruses. Our findings revealed a higher proportion of H5N1 than 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 p<0.05), respectively. The fatality rates for the total, index and secondary childhood cluster cases were 52.86% (37/70), 88.5% (23/26) and 33.33% (15/45), respectively, in the H5N1 group, whereas no fatal H7N9 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.

  6. A genetically engineered H5 protein expressed in insect cells confers protection against different clades of H5N1 highly pathogenic avian influenza viruses in chickens.

    PubMed

    Oliveira Cavalcanti, Marcia; Vaughn, Eric; Capua, Ilaria; Cattoli, Giovanni; Terregino, Calogero; Harder, Timm; Grund, Christian; Vega, Carlos; Robles, Francisco; Franco, Julio; Darji, Ayub; Arafa, Abdel-Satar; Mundt, Egbert

    2017-04-01

    The evolution of highly pathogenic H5N1 avian influenza viruses (HPAI-H5N1) has resulted in the appearance of a number of diverse groups of HPAI-H5N1 based on the presence of genetically similar clusters of their haemagglutinin sequences (clades). An H5 antigen encoded by a recombinant baculovirus and expressed in insect cells was used for oil-emulsion-based vaccine prototypes. In several experiments, vaccination was performed at 10 days of age, followed by challenge infection on day 21 post vaccination (PV) with HPAI-H5N1 clades 2.2, 2.2.1, and 2.3.2. A further challenge infection with HPAI-H5N1 clade 2.2.1 was performed at day 42 PV. High haemagglutination inhibition titres were observed for the recH5 vaccine antigen, and lower haemagglutination inhibition titres for the challenge virus antigens. Nevertheless, the rate of protection from mortality and clinical signs was 100% when challenged at 21 days PV and 42 days PV, indicating protection over the entire broiler chicken rearing period without a second vaccination. The unvaccinated control chickens mostly died between two and five days after challenge infection. A low level of viral RNA was detected by reverse transcription followed by a quantitative polymerase chain reaction in a limited number of birds for a short period after challenge infection, indicating a limited spread of HPAI-H5N1 at flock level. Furthermore, it was observed that the vaccine can be used in a differentiation infected from vaccinated animals (DIVA) approach, based on the detection of nucleoprotein antibodies in vaccinated/challenged chickens. The vaccine fulfilled all expectations of an inactivated vaccine after one vaccination against challenge with different clades of H5N1-HPAI and is suitable for a DIVA approach.

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed Central

    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 (<15 years old), as well as the childhood cluster cases of the two viruses. Our findings revealed a higher proportion of H5N1 than 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 p<0.05), respectively. The fatality rates for the total, index and secondary childhood cluster cases were 52.86% (37/70), 88.5% (23/26) and 33.33% (15/45), respectively, in the H5N1 group, whereas no fatal H7N9 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. Enhanced virulence of clade 2.3.2.1 highly pathogenic avian influenza A H5N1 viruses in ferrets.

    PubMed

    Pearce, Melissa B; Pappas, Claudia; Gustin, Kortney M; Davis, C Todd; Pantin-Jackwood, Mary J; Swayne, David E; Maines, Taronna R; Belser, Jessica A; Tumpey, Terrence M

    2017-02-01

    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, numerous subclades and genotypes have been described. To better understand the pathogenesis associated with the continued diversification of clade 2A(H5N1) influenza viruses, we investigated the relative virulence of eleven human and poultry isolates collected from 2006 to 2013 by determining their ability to cause disease in the ferret model. Numerous clade 2 viruses, including a clade 2.2 avian isolate, a 2.2.2.1 human isolate, and two 2.2.1 human isolates, were found to be of low virulence in the ferret model, though lethality was detected following infection with one 2.2.1 human isolate. In contrast, three of six clade 2.3.2.1 avian isolates tested led to severe disease and death among infected ferrets. Clade 2.3.2.1b and 2.3.2.1c isolates, but not 2.3.2.1a isolates, were associated with ferret lethality. All A(H5N1) viruses replicated efficiently in the respiratory tract of ferrets regardless of their virulence and lethality. However, lethal isolates were characterized by systemic viral dissemination, including detection in the brain and enhanced histopathology in lung tissues. The finding of disparate virulence phenotypes between clade 2A(H5N1) viruses, notably differences between subclades of 2.3.2.1 viruses, suggests there are distinct molecular determinants present within the established subclades, the identification of which will assist in molecular-based surveillance and public health efforts against A(H5N1) viruses.

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

    PubMed

    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.

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

    USGS Publications Warehouse

    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.

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

    PubMed Central

    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

  14. Short-Term Heat Shock Affects Host–Virus Interaction in Mice Infected with Highly Pathogenic Avian Influenza Virus H5N1

    PubMed Central

    Xue, Jia; Fan, Xiaoxu; Yu, Jing; Zhang, Shouping; Xiao, Jin; Hu, Yanxin; Wang, Ming

    2016-01-01

    Highly pathogenic avian influenza virus (HPAIV) H5N1 is a highly contagious virus that can cause acute respiratory infections and high human fatality ratio due to excessive inflammatory response. Short-term heat shock, as a stressful condition, could induce the expression of heat shock proteins that function as molecular chaperones to protect cells against multiple stresses. However, the protective effect of short-term heat shock in influenza infection is far from being understood. In this study, mice were treated at 39°C for 4 h before being infected with HPAIV H5N1. Interestingly, short-term heat shock significantly increased the levels of HSP70 and pro-inflammatory cytokines IL-6, TNF-α, IFN-β, and IFN-γ in the lung tissues of mice. Following HPAIV H5N1 infection, short-term heat shock alleviated immunopathology and viral replication in lung tissue and repressed the weight loss and increased the survival rate of H5N1-infected mice. Our data reported that short-term heat shock provided beneficial anti-HPAIV H5N1 properties in mice model, which offers an alternative strategy for non-drug prevention for influenza infection. PMID:27379054

  15. Therapeutic efficacy of peramivir against H5N1 highly pathogenic avian influenza viruses harboring the neuraminidase H275Y mutation.

    PubMed

    Kobayashi, Masanori; Kodama, Makoto; Noshi, Takeshi; Yoshida, Ryu; Kanazu, Takushi; Nomura, Naoki; Soda, Kosuke; Isoda, Norikazu; Okamatsu, Masatoshi; Sakoda, Yoshihiro; Yamano, Yoshinori; Sato, Akihiko; Kida, Hiroshi

    2017-03-01

    High morbidity and mortality associated with human cases of highly pathogenic avian influenza (HPAI) viruses, including H5N1 influenza virus, have been reported. The purpose of the present study was to evaluate the antiviral effects of peramivir against HPAI viruses. In neuraminidase (NA) inhibition and virus replication inhibition assays, peramivir showed strong inhibitory activity against H5N1, H7N1 and H7N7 HPAI viruses with sub-nanomolar activity in enzyme assays. In H5N1 viruses containing the NA H275Y mutation, the antiviral activity of peramivir against the variant was lower than that against the wild-type. Evaluation of the in vivo antiviral activity showed that a single intravenous treatment of peramivir (10 mg/kg) prevented lethality in mice infected with wild-type H5N1 virus and also following infection with H5N1 virus with the H275Y mutation after a 5 day administration of peramivir (30 mg/kg). Furthermore, mice injected with peramivir showed low viral titers and low levels of proinflammatory cytokines in the lungs. These results suggest that peramivir has therapeutic activity against HPAI viruses even if the virus harbors the NA H275Y mutation.

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

    PubMed

    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.

  17. Short-Term Heat Shock Affects Host-Virus Interaction in Mice Infected with Highly Pathogenic Avian Influenza Virus H5N1.

    PubMed

    Xue, Jia; Fan, Xiaoxu; Yu, Jing; Zhang, Shouping; Xiao, Jin; Hu, Yanxin; Wang, Ming

    2016-01-01

    Highly pathogenic avian influenza virus (HPAIV) H5N1 is a highly contagious virus that can cause acute respiratory infections and high human fatality ratio due to excessive inflammatory response. Short-term heat shock, as a stressful condition, could induce the expression of heat shock proteins that function as molecular chaperones to protect cells against multiple stresses. However, the protective effect of short-term heat shock in influenza infection is far from being understood. In this study, mice were treated at 39°C for 4 h before being infected with HPAIV H5N1. Interestingly, short-term heat shock significantly increased the levels of HSP70 and pro-inflammatory cytokines IL-6, TNF-α, IFN-β, and IFN-γ in the lung tissues of mice. Following HPAIV H5N1 infection, short-term heat shock alleviated immunopathology and viral replication in lung tissue and repressed the weight loss and increased the survival rate of H5N1-infected mice. Our data reported that short-term heat shock provided beneficial anti-HPAIV H5N1 properties in mice model, which offers an alternative strategy for non-drug prevention for influenza infection.

  18. Human Pulmonary Microvascular Endothelial Cells Support Productive Replication of Highly Pathogenic Avian Influenza Viruses: Possible Involvement in the Pathogenesis of Human H5N1 Virus Infection

    PubMed Central

    Zeng, Hui; Pappas, Claudia; Belser, Jessica A.; Houser, Katherine V.; Zhong, Weiming; Wadford, Debra A.; Stevens, Troy; Balczon, Ron; Katz, Jacqueline M.

    2012-01-01

    Highly pathogenic avian influenza (HPAI) H5N1 viruses continue to cause sporadic human infections with a high fatality rate. Respiratory failure due to acute respiratory distress syndrome (ARDS) is a complication among hospitalized patients. Since progressive pulmonary endothelial damage is the hallmark of ARDS, we investigated host responses following HPAI virus infection of human pulmonary microvascular endothelial cells. Evaluation of these cells for the presence of receptors preferred by influenza virus demonstrated that avian-like (α2-3-linked) receptors were more abundant than human-like (α2-6-linked) receptors. To test the permissiveness of pulmonary endothelial cells to virus infection, we compared the replication of selected seasonal, pandemic (2009 H1N1 and 1918), and potentially pandemic (H5N1) influenza virus strains. We observed that these cells support productive replication only of HPAI H5N1 viruses, which preferentially enter through and are released from the apical surface of polarized human endothelial monolayers. Furthermore, A/Thailand/16/2004 and A/Vietnam/1203/2004 (VN/1203) H5N1 viruses, which exhibit heightened virulence in mammalian models, replicated to higher titers than less virulent H5N1 strains. VN/1203 infection caused a significant decrease in endothelial cell proliferation compared to other subtype viruses. VN/1203 virus was also found to be a potent inducer of cytokines and adhesion molecules known to regulate inflammation during acute lung injury. Deletion of the H5 hemagglutinin (HA) multibasic cleavage site did not affect virus infectivity but resulted in decreased virus replication in endothelial cells. Our results highlight remarkable tropism and infectivity of the H5N1 viruses for human pulmonary endothelial cells, resulting in the potent induction of host inflammatory responses. PMID:22072765

  19. Prospective of Genomics in Revealing Transmission, Reassortment and Evolution of Wildlife-Borne Avian Influenza A (H5N1) Viruses

    PubMed Central

    Lei, Fumin; Shi, Weifeng

    2011-01-01

    The outbreak of highly pathogenic avian influenza (HPAI) H5N1 disease has led to significant loss of poultry and wild life and case fatality rates in humans of 60%. Wild birds are natural hosts for all avian influenza virus subtypes and over120 bird species have been reported with evidence of H5N1 infection. Influenza A viruses possess a segmented RNA genome and are characterized by frequently occurring genetic reassortment events, which play a very important role in virus evolution and the spread of novel gene constellations in immunologically naïve human and animal populations. Phylogenetic analysis of whole genome or sub-genomic sequences is a standard means for delineating genetic variation, novel reassortment events, and surveillance to trace the global transmission pathways. In this paper, special emphasis is given to the transmission and circulation of H5N1 among wild life populations, and to the reassortment events that are associated with inter-host transmission of the H5N1 viruses when they infect different hosts, such as birds, pigs and humans. In addition, we review the inter-subtype reassortment of the viral segments encoding inner proteins between the H5N1 viruses and viruses of other subtypes, such as H9N2 and H6N1. Finally, we highlight the usefulness of genomic sequences in molecular epidemiological analysis of HPAI H5N1 and the technical limitations in existing analytical methods that hinder them from playing a greater role in virological research. PMID:22547954

  20. Detection of distribution of avian influenza H5N1 virus by immunohistochemistry, chromogenic in situ hybridization and real-time PCR techniques in experimentally infected chickens.

    PubMed

    Chamnanpood, Chanpen; Sanguansermsri, Donruedee; Pongcharoen, Sutatip; Sanguansermsri, Phanchana

    2011-03-01

    Ten specific pathogen free (SPF) chickens were inoculated intranasally with avian influenza virus subtype H5N1. Evaluation revealed distribution of the virus in twelve organs: liver, intestine, bursa, lung, trachea, thymus, heart, pancreas, brain, spleen, kidney, and esophagus. Immunohistochemistry (IHC), chromogenic in situ hybridization (CISH), and real-time polymerase chain reaction (PCR) were developed and compared for detection of the virus from the organs. The distribution of avian influenza H5N1 in chickens varied by animal and detecting technique. The heart, kidneys, intestines, lungs, and pancreas were positive with all three techniques, while the others varied by techique. The three techniques can be used to detect avian influenza effectively, but the pros and cons of each technique need to be determined. The decision of which technique to use depends on the objective of the examination, budget, type and quality of samples, laboratory facilities and technician skills.

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

    USGS Publications Warehouse

    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.

  2. The genome sequence analysis of H5N1 avian influenza A virus isolated from the outbreak among poultry populations in Thailand.

    PubMed

    Viseshakul, Nareerat; Thanawongnuwech, Roongroje; Amonsin, Alongkorn; Suradhat, Sanipa; Payungporn, Sunchai; Keawchareon, Juthatip; Oraveerakul, Kanisak; Wongyanin, Piya; Plitkul, Sukanya; Theamboonlers, Apiradee; Poovorawan, Yong

    2004-10-25

    In this report, the genome of the Thai avian influenza virus A (H5N1); A/Chicken/Nakorn-Pathom/Thailand/CU-K2/04, isolated from the Thai avian influenza A (AI) epidemic during the early of 2004 was sequenced. Phylogenetic analyses were performed in comparison to AI viruses from Hong Kong 1997 outbreaks and other AI (H5N1) isolates reported during 2001-2004. Molecular characterization of the Thai AI (H5N1) HA gene revealed a common characteristic of a highly pathogenic AI (HPAI), a 20-codon deletion in the neuraminidase gene, a 5-codon deletion in the NS gene and polymorphisms of the M2 and PB2 genes. Moreover, the HA and NA genes of the Thai AI displayed high similarity to those of the AI viruses isolated from human cases during the same epidemic. Finally, our results demonstrated that the Thai AI emerged as a member of 2000's AI lineage with most of the genetic sequences closely related to the Influenza A/Duck/China/E319.2/03 (H5N1).

  3. Movements of wild ruddy shelducks in the Central Asian Flyway and their spatial relationship to outbreaks of highly pathogenic avian influenza H5N1

    USGS Publications Warehouse

    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.

  4. Identification and characterization of a highly pathogenic H5N1 avian influenza A virus during an outbreak in vaccinated chickens in Egypt.

    PubMed

    Amen, O; Vemula, S V; Zhao, J; Ibrahim, R; Hussein, A; Hewlett, I K; Moussa, S; Mittal, S K

    2015-12-02

    Highly pathogenic avian influenza A (HPAI) H5N1 viruses continue to be a major veterinary and public health problem in Egypt. Continued surveillance of these viruses is necessary to devise strategies to control the spread of the virus and to monitor its evolutionary patterns. This is a report of the identification of a variant strain of HPAI H5N1 virus during an outbreak in 2010 in vaccinated chicken flocks in a poultry farm in Assiut, Egypt. Vaccination of chickens with an oil-emulsified inactivated A/chicken/Mexico/232/94 (H5N2) vaccine induced high levels of hemagglutination inhibition (HI) antibody titers reaching up to 9 log2. However, all flocks irrespective of the number of vaccine doses and the resultant HI titer levels came down with severe influenza infections. The qRT-PCR and rapid antigen test confirmed the influenza virus to be from H5N1 subtype. Sequencing of the hemagglutinin (HA) gene fragment from ten independent samples demonstrated that a single H5N1 strain was involved. This strain belonged to clade 2.2.1 and had several mutations in the receptor-binding site of the HA protein, thereby producing a variant strain of HPAI H5N1 virus which was antigenically different from the parent clade 2.2.1 virus circulating in Egypt at that time. In order to define the variability in HPAI H5N1 viruses over time in Egypt, we sequenced another H5N1 virus that was causing infections in chickens in 2014. Phylogenetic analysis revealed that both viruses had further distanced from the parent virus circulating during 2010. This study highlights that the antigenic mutations in HPAI H5N1 viruses represent a definitive challenge for the development of an effective vaccine for poultry. Overall, the results emphasize the need for continued surveillance of H5N1 outbreaks and extensive characterization of virus isolates from vaccinated and non-vaccinated poultry populations to better understand genetic changes and their implications.

  5. Genetically Different Highly Pathogenic Avian Influenza A(H5N1) Viruses in West Africa, 2015

    PubMed Central

    Tassoni, Luca; Fusaro, Alice; Milani, Adelaide; Lemey, Philippe; Awuni, Joseph Adongo; Sedor, Victoria Bernice; Dogbey, Otilia; Commey, Abraham Nii Okai; Meseko, Clement; Joannis, Tony; Minoungou, Germaine L.; Ouattara, Lassina; Haido, Abdoul Malick; Cisse-Aman, Diarra; Couacy-Hymann, Emmanuel; Dauphin, Gwenaelle; Cattoli, Giovanni

    2016-01-01

    To trace the evolution of highly pathogenic influenza A(H5N1) virus in West Africa, we sequenced genomes of 43 viruses collected during 2015 from poultry and wild birds in 5 countries. We found 2 co-circulating genetic groups within clade 2.3.2.1c. Mutations that may increase adaptation to mammals raise concern over possible risk for humans. PMID:27389972

  6. Development of Disease-specific, Context-specific Surveillance Models: Avian Influenza (H5N1)-Related Risks and Behaviours in African Countries.

    PubMed

    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.

  7. Glycine at Position 622 in PB1 Contributes to the Virulence of H5N1 Avian Influenza Virus in Mice

    PubMed Central

    Feng, Xiaoxiao; Wang, Zeng; Shi, Jianzhong; Deng, Guohua; Kong, Huihui; Tao, Shiyu; Li, Changyao; Liu, Liling; Guan, Yuntao

    2015-01-01

    ABSTRACT We isolated two H5N1 viruses, A/duck/Hunan/S4020/2008 (DK/08) and A/chicken/Guangxi/S2039/2009 (CK/09), from live-bird markets during routine surveillance and found that these two viruses are genetically similar but differ in their replication and virulence in mice. The CK/09 virus is lethal for mice with a 50% mouse lethal dose (MLD50) of 1.6 log10 50% egg infectious doses (EID50), whereas the DK/08 virus is nonpathogenic for mice with an MLD50 value of 6.2 log10 EID50. We explored the genetic basis of the virulence difference of these two viruses by generating a series of reassortant viruses and mutants in the lethal virus CK/09 background and evaluating their virulence in mice. We found that the PB1 gene of the DK/08 virus dramatically attenuated the virulence of the CK/09 virus and that the amino acid at position 622 in PB1 made an important contribution. We further demonstrated that the mutation of glycine (G) to aspartic acid (D) at position 622 in PB1 partially impaired the binding of PB1 to viral RNA, thereby dramatically decreasing the polymerase activity and attenuating H5N1 virus virulence in mice. Our results identify a novel virulence-related marker of H5N1 influenza viruses and provide a new target for live attenuated vaccine development. IMPORTANCE H5N1 avian influenza viruses have caused the deaths of nearly 60% of the humans that they have infected since 1997 and clearly represent a threat to public health. A thorough understanding of the genetic basis of virulence determinants will provide important insights for antiviral drug and live attenuated vaccine development. Several virulence-related markers in the PB2, PA, M1, and NS1 proteins of H5N1 viruses have been identified. In this study, we isolated two H5N1 avian influenza viruses that are genetically similar but differ in their virulence in mice, and we identified a new virulence-related marker in the PB1 gene. We found that the mutation of glycine (G) to aspartic acid (D) at position

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

    PubMed Central

    Kallon, Sanpha; Yu, Xingang

    2016-01-01

    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. PMID:27597953

  9. Eco-virological approach for assessing the role of wild birds in the spread of avian influenza H5N1 along the Central Asian Flyway.

    PubMed

    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.

  10. Characterization of the amantadine-resistant H5N1 highly pathogenic avian influenza variants isolated from quails in Southern China.

    PubMed

    Dong, Guoying; Luo, Jing; Zhou, Kai; Wu, Bin; Peng, Chao; Ji, Guangju; He, Hongxuan

    2014-10-01

    Highly pathogenic H5N1 avian influenza viruses have spread in poultry and wild birds in Asia, Europe, and Africa since 2003. To evaluate the role of quails in the evolution of influenza A virus, we characterized three H5N1 viruses isolated from quails (QA viruses) in southern China. Phylogenetic analysis indicated that three QA viruses derived from the A/goose/Guangdong/1/96-like lineage and most closely related to HA clade 4 A/chicken/Hong Kong/31.4/02-like viruses. Molecular analysis suggested that QA viruses and clade 4 H5N1 viruses carried consistent residue signatures, such as the characteristic M2 Ser31Asn amantadine-resistance mutation, implying a common origin of these viruses. As revealed by viral pathogenicity tests, these QA viruses could replicate in intranasally infected mice, but were not lethal to them, showing low pathogenicity in mammals. However, they killed all intravenously inoculated chickens, showing high pathogenicity in poultry. Results from amantadine sensitivity tests of wild-type QA viruses and their reverse genetic viruses demonstrated that all QA viruses were resistant to amantadine, and the M2 Ser31Asn mutation was determined as the most likely cause of the increased amantadine-resistance of H5N1 QA viruses. Our study confirmed experimentally that the amino acid at residue 31 in the M2 protein plays a major role in determining the amantadine-resistance phenotype of H5N1 influenza viruses. Our findings provide further evidence that quails may play important roles in the evolution of influenza A viruses, which raises concerns over possible transmissions of H5N1 viruses among poultry, wild birds, and humans.

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

    USGS Publications Warehouse

    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.

  12. Lessons from emergence of A/goose/Guangdong/1996-like H5N1 highly pathogenic avian influenza viruses and recent influenza surveillance efforts in southern China.

    PubMed

    Wan, X F

    2012-09-01

    Southern China is proposed as an influenza epicentre. At least two of the three pandemics in the last century, including 1957 and 1968 influenza pandemics, originated from this area. In 1996, A/goose/Guangdong/1/1996 (H5N1), the precursor of currently circulating highly pathogenic H5N1 avian influenza viruses (HPAIVs) was identified in farmed geese in southern China. These H5N1 HPAIVs have been spread across Asia, Europe and Africa and poses a continuous threat to both animal and human health. However, how and where this H5N1 HPAIV emerged are not fully understood. In the past decade, many influenza surveillance efforts have been carried out in southern China, and our understanding of the genetic diversity of non-human influenza A viruses in this area has been much better than ever. Here, the historical and first-hand experimental data on A/goose/Guangdong/1/1996(H5N1)-like HPAIVs are reviewed within the context of the findings from recent surveillance efforts on H5N1 HPAIVs and other non-human influenza A viruses. Such a retrospective recapitulation suggests that long-term and systematic surveillance programmes should continue to be implemented in southern China that the wet markets on the animal-human interface shall be the priority area and that the surveillance on the animal species bridging the interface between wildlife and domestic animal populations and the interface between the aquatics and territories shall be the strengthened.

  13. Quantified degree of poultry exposure differs for human cases of avian influenza H5N1 and H7N9.

    PubMed

    Bethmont, A; Bui, C M; Gardner, L; Sarkar, S; Chughtai, A A; Macintyre, C R

    2016-09-01

    Preliminary evidence suggests that direct poultry contact may play a lesser role in transmission of avian influenza A(H7N9) than A(H5N1) to humans. To better understand differences in risk factors, we quantified the degree of poultry contact reported by H5N1 and H7N9 World Health Organization-confirmed cases. We used publicly available data to classify cases by their degree of poultry contact, including direct and indirect. To account for potential data limitations, we used two methods: (1) case population method in which all cases were classified using a range of sources; and (2) case subset method in which only cases with detailed contact information from published research literature were classified. In the case population, detailed exposure information was unavailable for a large proportion of cases (H5N1, 54%; H7N9, 86%). In the case subset, direct contact proportions were higher in H5N1 cases (70·3%) than H7N9 cases (40·0%) (χ 2 = 18·5, P < 0·001), and indirect contact proportions were higher in H7N9 cases (44·6%) than H5N1 cases (19·4%) (χ 2 = 15·5, P < 0·001). Together with emerging evidence, our descriptive analysis suggests direct poultry contact is a clearer risk factor for H5N1 than for H7N9, and that other risk factors should also be considered for H7N9.

  14. Efficient strategy for constructing duck enteritis virus-based live attenuated vaccine against homologous and heterologous H5N1 avian influenza virus and duck enteritis virus infection.

    PubMed

    Zou, Zhong; Hu, Yong; Liu, Zhigang; Zhong, Wei; Cao, Hangzhou; Chen, Huanchun; Jin, Meilin

    2015-04-16

    Duck is susceptible to many pathogens, such as duck hepatitis virus, duck enteritis virus (DEV), duck tembusu virus, H5N1 highly pathogenic avian influenza virus (HPAIV) in particular. With the significant role of duck in the evolution of H5N1 HPAIV, control and eradication of H5N1 HPAIV in duck through vaccine immunization is considered an effective method in minimizing the threat of a pandemic outbreak. Consequently, a practical strategy to construct a vaccine against these pathogens should be determined. In this study, the DEV was examined as a candidate vaccine vector to deliver the hemagglutinin (HA) gene of H5N1, and its potential as a polyvalent vaccine was evaluated. A modified mini-F vector was inserted into the gB and UL26 gene junction of the attenuated DEV vaccine strain C-KCE genome to generate an infectious bacterial artificial chromosome (BAC) of C-KCE (vBAC-C-KCE). The HA gene of A/duck/Hubei/xn/2007 (H5N1) was inserted into the C-KCE genome via the mating-assisted genetically integrated cloning (MAGIC) to generate the recombinant vector pBAC-C-KCE-HA. A bivalent vaccine C-KCE-HA was developed by eliminating the BAC backbone. Ducks immunized with C-KCE-HA induced both the cross-reactive antibodies and T cell response against H5. Moreover, C-KCE-HA-immunized ducks provided rapid and long-lasting protection against homologous and heterologous HPAIV H5N1 and DEV clinical signs, death, and primary viral replication. In conclusion, our BAC-C-KCE is a promising platform for developing a polyvalent live attenuated vaccine.

  15. Outbreaks of avian influenza A (H5N2), (H5N8), and (H5N1) among birds--United States, December 2014-January 2015.

    PubMed

    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.

  16. D701N mutation in the PB2 protein contributes to the pathogenicity of H5N1 avian influenza viruses but not transmissibility in guinea pigs.

    PubMed

    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.

  17. Will the next human influenza pandemic be caused by the virus of the avian flu A/H5N1? Arguments pro and counter.

    PubMed

    Doerr, H W; Varwig, Domenica; Allwinn, Regina; Cinatl, J

    2006-06-01

    In 1997, the avian influenza A subtype H5N1 that caused big outbreaks of fowl pest in mass poultry farming had emerged in Hong Kong. Its spread throughout Eurasia had given rise to concerns in terms of the possible imminence of the next human influenza pandemic. In this article, epidemiological and virological arguments supporting or declining this fear are outlined and discussed with regard to viral infectivity and pathogenicity.

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

    PubMed

    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.

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

    USGS Publications Warehouse

    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.

  20. Encephalitis in a stone marten (Martes foina) after natural infection with highly pathogenic avian influenza virus subtype H5N1.

    PubMed

    Klopfleisch, R; Wolf, P U; Wolf, C; Harder, T; Starick, E; Niebuhr, M; Mettenleiter, T C; Teifke, J P

    2007-01-01

    Recent outbreaks of disease in different avian species, caused by the highly pathogenic avian influenza virus (HPAIV), have involved infection by subtype H5N1 of the virus. This virus has also crossed species barriers and infected felines and humans. Here, we report the natural infection of a stone marten (Martes foina) from an area with numerous confirmed cases of H5N1 HPAIV infection in wild birds. Histopathological examination of tissues from this animal revealed a diffuse nonsuppurative panencephalitis with perivascular cuffing, multifocal gliosis and neuronal necrosis. Additionally, focal necrosis of pancreatic acinar cells was observed. Immunohistochemically, lesions in these organs were associated with avian influenza virus antigen in neurons, glial cells and pancreatic acinar cells. Thus, the microscopical lesions and viral antigen distribution in this stone marten differs from that recently described for cats naturally and experimentally infected with the same virus subtype. This is the first report of natural infection of a mustelid with HPAIV H5N1.

  1. Mucosal immunity induced by adenovirus-based H5N1 HPAI vaccine confers protection against a lethal H5N2 avian influenza virus challenge

    SciTech Connect

    Park, Ki Seok; Lee, Jiyeung; Ahn, So Shin; Byun, Young-Ho; Seong, Baik Lin; Baek, Yun Hee; Song, Min-Suk; Choi, Young Ki; Na, Yun Jeong; Hwang, Inhwan; Sung, Young Chul; Lee, Chang Geun

    2009-12-20

    Development of effective vaccines against highly pathogenic avian influenza (HPAI) H5N1 viruses is a global public health priority. Considering the difficulty in predicting HPAI H5N1 pandemic strains, one strategy used in their design includes the development of formulations with the capacity of eliciting broad cross-protective immunity against multiple viral antigens. To this end we constructed a replication-defective recombinant adenovirus-based avian influenza virus vaccine (rAdv-AI) expressing the codon-optimized M2eX-HA-hCD40L and the M1-M2 fusion genes from HPAI H5N1 human isolate. Although there were no significant differences in the systemic immune responses observed between the intramuscular prime-intramuscular boost regimen (IM/IM) and the intranasal prime-intramuscular boost regimen (IN/IM), IN/IM induced more potent CD8{sup +} T cell and antibody responses at mucosal sites than the IM/IM vaccination, resulting in more effective protection against lethal H5N2 avian influenza (AI) virus challenge. These findings suggest that the strategies used to induce multi-antigen-targeted mucosal immunity, such as IN/IM delivery of rAdv-AI, may be a promising approach for developing broad protective vaccines that may be more effective against the new HPAI pandemic strains.

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

    PubMed

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

    PubMed

    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.

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

    PubMed

    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.

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

    USGS Publications Warehouse

    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.

  6. Biological characterization of highly pathogenic avian influenza H5N1 viruses that infected humans in Egypt in 2014-2015.

    PubMed

    El-Shesheny, Rabeh; Mostafa, Ahmed; Kandeil, Ahmed; Mahmoud, Sara H; Bagato, Ola; Naguib, Amel; Refaey, Samir El; Webby, Richard J; Ali, Mohamed A; Kayali, Ghazi

    2017-03-01

    Highly pathogenic avian influenza (HPAI) H5N1 influenza viruses emerged as a human pathogen in 1997 with expected potential to undergo sustained human-to-human transmission and pandemic viral spread. HPAI H5N1 is endemic in Egyptian poultry and has caused sporadic human infection. The first outbreak in early 2006 was caused by clade 2.2 viruses that rapidly evolved genetically and antigenically. A sharp increase in the number of human cases was reported in Egypt in the 2014/2015 season. In this study, we analyzed and characterized three isolates of HPAI H5N1 viruses isolated from infected humans in Egypt in 2014/2015. Phylogenetic analysis demonstrated that the nucleotide sequences of eight segments of the three isolates were clustered with those of members of clade 2.2.1.2. We also found that the human isolates from 2014/2015 had a slight, non-significant difference in their affinity for human-like sialic acid receptors. In contrast, they showed significant differences in their replication kinetics in MDCK, MDCK-SIAT, and A549 cells as well as in embryonated chicken eggs. An antiviral bioassay study revealed that all of the isolates were susceptible to amantadine. Therefore, further investigation and monitoring is required to correlate the genetic and/or antigenic changes of the emerging HPAI H5N1 viruses with possible alteration in their characteristics and their potential to become a further threat to public health.

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

    PubMed

    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.

  8. A duck enteritis virus-vectored bivalent live vaccine provides fast and complete protection against H5N1 avian influenza virus infection in ducks.

    PubMed

    Liu, Jinxiong; Chen, Pucheng; Jiang, Yongping; Wu, Li; Zeng, Xianying; Tian, Guobin; Ge, Jinying; Kawaoka, Yoshihiro; Bu, Zhigao; Chen, Hualan

    2011-11-01

    Ducks play an important role in the maintenance of highly pathogenic H5N1 avian influenza viruses (AIVs) in nature, and the successful control of AIVs in ducks has important implications for the eradication of the disease in poultry and its prevention in humans. The inactivated influenza vaccine is expensive, labor-intensive, and usually needs 2 to 3 weeks to induce protective immunity in ducks. Live attenuated duck enteritis virus (DEV; a herpesvirus) vaccine is used routinely to control lethal DEV infections in many duck-producing areas. Here, we first established a system to generate the DEV vaccine strain by using the transfection of overlapping fosmid DNAs. Using this system, we constructed two recombinant viruses, rDEV-ul41HA and rDEV-us78HA, in which the hemagglutinin (HA) gene of the H5N1 virus A/duck/Anhui/1/06 was inserted and stably maintained within the ul41 gene or between the us7 and us8 genes of the DEV genome. Duck studies indicated that rDEV-us78HA had protective efficacy similar to that of the live DEV vaccine against lethal DEV challenge; importantly, a single dose of 10(6) PFU of rDEV-us78HA induced complete protection against a lethal H5N1 virus challenge in as little as 3 days postvaccination. The protective efficacy against both lethal DEV and H5N1 challenge provided by rDEV-ul41HA inoculation in ducks was slightly weaker than that provided by rDEV-us78HA. These results demonstrate, for the first time, that recombinant DEV is suitable for use as a bivalent live attenuated vaccine, providing rapid protection against both DEV and H5N1 virus infection in ducks.

  9. Satellite Tracking on the Flyways of Brown-Headed Gulls and Their Potential Role in the Spread of Highly Pathogenic Avian Influenza H5N1 Virus

    PubMed Central

    Ratanakorn, Parntep; Wiratsudakul, Anuwat; Wiriyarat, Witthawat; Eiamampai, Krairat; Farmer, Adrian H.; Webster, Robert G.; Chaichoune, Kridsada; Suwanpakdee, Sarin; Pothieng, Duangrat; Puthavathana, Pilaipan

    2012-01-01

    Brown-headed gulls (Larus brunnicephalus), winter visitors of Thailand, were tracked by satellite telemetry during 2008–2011 for investigating their roles in the highly pathogenic avian influenza (HPAI) H5N1 virus spread. Eight gulls negative for influenza virus infection were marked with solar-powered satellite platform transmitters at Bang Poo study site in Samut Prakarn province, Thailand; their movements were monitored by the Argos satellite tracking system, and locations were mapped. Five gulls completed their migratory cycles, which spanned 7 countries (China, Bangladesh, India, Myanmar, Thailand, Cambodia, and Vietnam) affected by the HPAI H5N1 virus. Gulls migrated from their breeding grounds in China to stay overwinter in Thailand and Cambodia; while Bangladesh, India, Myanmar, and Vietnam were the places of stopovers during migration. Gulls traveled an average distance of about 2400 km between Thailand and China and spent 1–2 weeks on migration. Although AI surveillance among gulls was conducted at the study site, no AI virus was isolated and no H5N1 viral genome or specific antibody was detected in the 75 gulls tested, but 6.6% of blood samples were positive for pan-influenza A antibody. No AI outbreaks were reported in areas along flyways of gulls in Thailand during the study period. Distance and duration of migration, tolerability of the captive gulls to survive the HPAI H5N1 virus challenge and days at viral shedding after the virus challenging suggested that the Brown-headed gull could be a potential species for AI spread, especially among Southeast Asian countries, the epicenter of H5N1 AI outbreak. PMID:23209623

  10. Differential cellular gene expression in duck trachea infected with a highly or low pathogenic H5N1 avian influenza virus

    PubMed Central

    2013-01-01

    Background Avian influenza A (AI) viruses of subtypes H5 can cause serious disease outbreaks in poultry including panzootic due to H5N1 highly pathogenic (HP) viruses. These viruses are a threat not only for animal health but also public health due to their zoonotic potential. The domestic duck plays a major role in the epidemiological cycle of influenza virus subtypes H5 but little is known concerning host/pathogen interactions during influenza infection in duck species. In this study, a subtracted library from duck trachea (a primary site of influenza virus infection) was constructed to analyse and compare the host response after a highly or low pathogenic (LP) H5N1-infection. Results Here, we show that more than 200 different genes were differentially expressed in infected duck trachea to a significant degree. In addition, significant differentially expressed genes between LPAI- and HPAI-infected tracheas were observed. Gene ontology annotation was used and specific signalling pathways were identified. These pathways were different for LPAI and HPAI-infected tracheas, except for the CXCR4 signalling pathway which is implicated in immune response. A different modulation of genes in the CXCR4 signalling pathway and TRIM33 was induced in duck tracheas infected with a HPAI- or a LPAI-H5N1. Conclusion First, this study indicates that Suppressive Subtractive Hybridization (SSH) is an alternative approach to gain insights into the pathogenesis of influenza infection in ducks. Secondly, the results indicate that cellular gene expression in the duck trachea was differently modulated after infection with a LPAI-H5N1 or after infection with a HPAI-H5N1 virus. Such difference found in infected trachea, a primary infection site, could precede continuation of infection and could explain appearance of respiratory symptoms or not. PMID:24015922

  11. Satellite tracking on the flyways of brown-headed gulls and their potential role in the spread of highly pathogenic avian influenza H5N1 virus.

    PubMed

    Ratanakorn, Parntep; Wiratsudakul, Anuwat; Wiriyarat, Witthawat; Eiamampai, Krairat; Farmer, Adrian H; Webster, Robert G; Chaichoune, Kridsada; Suwanpakdee, Sarin; Pothieng, Duangrat; Puthavathana, Pilaipan

    2012-01-01

    Brown-headed gulls (Larus brunnicephalus), winter visitors of Thailand, were tracked by satellite telemetry during 2008-2011 for investigating their roles in the highly pathogenic avian influenza (HPAI) H5N1 virus spread. Eight gulls negative for influenza virus infection were marked with solar-powered satellite platform transmitters at Bang Poo study site in Samut Prakarn province, Thailand; their movements were monitored by the Argos satellite tracking system, and locations were mapped. Five gulls completed their migratory cycles, which spanned 7 countries (China, Bangladesh, India, Myanmar, Thailand, Cambodia, and Vietnam) affected by the HPAI H5N1 virus. Gulls migrated from their breeding grounds in China to stay overwinter in Thailand and Cambodia; while Bangladesh, India, Myanmar, and Vietnam were the places of stopovers during migration. Gulls traveled an average distance of about 2400 km between Thailand and China and spent 1-2 weeks on migration. Although AI surveillance among gulls was conducted at the study site, no AI virus was isolated and no H5N1 viral genome or specific antibody was detected in the 75 gulls tested, but 6.6% of blood samples were positive for pan-influenza A antibody. No AI outbreaks were reported in areas along flyways of gulls in Thailand during the study period. Distance and duration of migration, tolerability of the captive gulls to survive the HPAI H5N1 virus challenge and days at viral shedding after the virus challenging suggested that the Brown-headed gull could be a potential species for AI spread, especially among Southeast Asian countries, the epicenter of H5N1 AI outbreak.

  12. Mammalian Innate Resistance to Highly Pathogenic Avian Influenza H5N1 Virus Infection Is Mediated through Reduced Proinflammation and Infectious Virus Release

    PubMed Central

    Nelli, Rahul K.; Dunham, Stephen P.; Kuchipudi, Suresh V.; White, Gavin A.; Baquero-Perez, Belinda; Chang, Pengxiang; Ghaemmaghami, Amir; Brookes, Sharon M.; Brown, Ian H.

    2012-01-01

    Respiratory epithelial cells and macrophages are the key innate immune cells that play an important role in the pathogenesis of influenza A virus infection. We found that these two cell types from both human and pig showed comparable susceptibilities to initial infection with a highly pathogenic avian influenza (HPAI) H5N1 virus (A/turkey/Turkey/1/05) and a moderately pathogenic human influenza H1N1 virus (A/USSR/77), but there were contrasting differences in host innate immune responses. Human cells mounted vigorous cytokine (tumor necrosis factor alpha [TNF-α] and interleukin-6 [IL-6]) and chemokine (CXCL9, CXCL10, and CXCL11) responses to H5N1 virus infection. However, pig epithelial cells and macrophages showed weak or no TNF-α and chemokine induction with the same infections. The apparent lack of a strong proinflammatory response, corroborated by the absence of TNF-α induction in H5N1 virus-challenged pigs, coincided with greater cell death and the reduced release of infectious virus from infected pig epithelial cells. Suppressor of cytokine signaling 3 (SOCS3), a protein suppressor of the JAK-STAT pathway, was constitutively highly expressed and transcriptionally upregulated in H5N1 virus-infected pig epithelial cells and macrophages, in contrast to the corresponding human cells. The overexpression of SOCS3 in infected human macrophages dampened TNF-α induction. In summary, we found that the reported low susceptibility of pigs to contemporary Eurasian HPAI H5N1 virus infections coincides at the level of innate immunity of respiratory epithelial cells and macrophages with a reduced output of viable virus and an attenuated proinflammatory response, possibly mediated in part by SOCS3, which could serve as a target in the treatment or prevention of virus-induced hypercytokinemia, as observed for humans. PMID:22718824

  13. Prophylactic and Therapeutic Efficacy of Avian Antibodies Against Influenza Virus H5N1 and H1N1 in Mice

    PubMed Central

    Nguyen, Huan H.; Tumpey, Terrence M.; Park, Hae-Jung; Byun, Young-Ho; Tran, Linh D.; Nguyen, Van D.; Kilgore, Paul E.; Czerkinsky, Cecil; Katz, Jacqueline M.; Seong, Baik Lin; Song, Jae Min; Kim, Young Bong; Do, Hoa T.; Nguyen, Tung; Nguyen, Cam V.

    2010-01-01

    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-specific IgY as affordable

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

    PubMed

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

    2014-01-01

    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.

  15. Pre-existing cross-reactive antibodies to avian influenza H5N1 and 2009 pandemic H1N1 in US military personnel.

    PubMed

    Pichyangkul, Sathit; Krasaesub, Somporn; Jongkaewwattana, Anan; Thitithanyanont, Arunee; Wiboon-Ut, Suwimon; Yongvanitchit, Kosol; Limsalakpetch, Amporn; Kum-Arb, Utaiwan; Mongkolsirichaikul, Duangrat; Khemnu, Nuanpan; Mahanonda, Rangsini; Garcia, Jean-Michel; Mason, Carl J; Walsh, Douglas S; Saunders, David L

    2014-01-01

    We studied cross-reactive antibodies against avian influenza H5N1 and 2009 pandemic (p) H1N1 in 200 serum samples from US military personnel collected before the H1N1 pandemic. Assays used to measure antibodies against viral proteins involved in protection included a hemagglutination inhibition (HI) assay and a neuraminidase inhibition (NI) assay. Viral neutralization by antibodies against avian influenza H5N1 and 2009 pH1N1 was assessed by influenza (H5) pseudotyped lentiviral particle-based and H1N1 microneutralization assays. Some US military personnel had cross-neutralizing antibodies against H5N1 (14%) and 2009 pH1N1 (16.5%). The odds of having cross-neutralizing antibodies against 2009 pH1N1 were 4.4 times higher in subjects receiving more than five inactivated whole influenza virus vaccinations than those subjects with no record of vaccination. Although unclear if the result of prior vaccination or disease exposure, these pre-existing antibodies may prevent or reduce disease severity.

  16. Rapid detection of highly pathogenic avian influenza H5N1 virus by TaqMan reverse transcriptase-polymerase chain reaction.

    PubMed

    Heine, H G; Trinidad, L; Selleck, P; Lowther, S

    2007-03-01

    Highly pathogenic avian influenza (AI) H5N1 viruses have been spreading from Asia since late 2003. Early detection and classification are paramount for control of the disease because these viruses are lethal to birds and have caused fatalities in humans. Here, we described TaqMan reverse transcriptase-polymerase chain reaction assays for rapid detection of all AI viruses (influenza type A) and for identification of H5N1 of the Eurasian lineage. The assays were sensitive and quantitative over a 10(5)-10(6) linear range, detected all of the tested AI viruses, and enabled differentiation between H5 and H7 subtypes. These tests allow definitive confirmation of an AI virus as H5 within hours, which is crucial for rapid implementation of control measures in the event of an outbreak.

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

    USGS Publications Warehouse

    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

  18. Highly pathogenic H5N1 avian influenza viruses differentially affect gene expression in primary chicken embryo fibroblasts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic avian influenza viruses cause severe clinical disease associated with high mortality in chickens and other gallinaceous species. However, the mechanism by which different strains of avian influenza viruses overcome host response in birds is still unclear. In the present study, ch...

  19. The immune correlates of protection for an avian influenza H5N1 vaccine in the ferret model using oil-in-water adjuvants.

    PubMed

    Wong, Sook-San; Duan, Susu; DeBeauchamp, Jennifer; Zanin, Mark; Kercher, Lisa; Sonnberg, Stephanie; Fabrizio, Thomas; Jeevan, Trushar; Crumpton, Jeri-Carol; Oshansky, Christine; Sun, Yilun; Tang, Li; Thomas, Paul; Webby, Richard

    2017-03-17

    Because of the pathogenicity and low incidence of avian influenza virus infections in humans, the immune correlates of protection for avian influenza vaccines cannot be determined from clinical studies. Here, we used the ferret model to address this for an avian influenza H5N1 vaccine. Using oil-in-water adjuvants, we generated groups of ferrets with undetectable (geometric mean titer [GMT] < 10), low (GMT = 28.3), or high (GMT > 761.1) hemagglutination-inhibition (HAI) titers to the A/Viet Nam/1203/2004 (H5N1) virus. Ferrets were then challenged with the wild-type virus and disease severity and immunologic parameters were studied. The severity of infection and symptom profile were inversely associated with pre-challenge HAI titers in a dose-dependent manner. A vaccinated ferret with no detectable HAI-antibodies but high flu-specific IgG-antibody titers mounted rapid functional antibodies after infection and experienced milder disease compared to other ferrets in the group. Compared to naïve ferrets, all vaccinated ferrets showed improved cellular immunity in the lungs and peripheral blood. High number of IFNγ(+) CD8- T cells in the airways was associated with early viral clearance. Thus, while neutralizing antibodies are the best correlate of protection, non-neutralizing antibodies can also be protective. This should be taken into consideration in future avian influenza vaccine trials.

  20. The immune correlates of protection for an avian influenza H5N1 vaccine in the ferret model using oil-in-water adjuvants

    PubMed Central

    Wong, Sook-San; Duan, Susu; DeBeauchamp, Jennifer; Zanin, Mark; Kercher, Lisa; Sonnberg, Stephanie; Fabrizio, Thomas; Jeevan, Trushar; Crumpton, Jeri-Carol; Oshansky, Christine; Sun, Yilun; Tang, Li; Thomas, Paul; Webby, Richard

    2017-01-01

    Because of the pathogenicity and low incidence of avian influenza virus infections in humans, the immune correlates of protection for avian influenza vaccines cannot be determined from clinical studies. Here, we used the ferret model to address this for an avian influenza H5N1 vaccine. Using oil-in-water adjuvants, we generated groups of ferrets with undetectable (geometric mean titer [GMT] < 10), low (GMT = 28.3), or high (GMT > 761.1) hemagglutination-inhibition (HAI) titers to the A/Viet Nam/1203/2004 (H5N1) virus. Ferrets were then challenged with the wild-type virus and disease severity and immunologic parameters were studied. The severity of infection and symptom profile were inversely associated with pre-challenge HAI titers in a dose-dependent manner. A vaccinated ferret with no detectable HAI-antibodies but high flu-specific IgG-antibody titers mounted rapid functional antibodies after infection and experienced milder disease compared to other ferrets in the group. Compared to naïve ferrets, all vaccinated ferrets showed improved cellular immunity in the lungs and peripheral blood. High number of IFNγ+ CD8- T cells in the airways was associated with early viral clearance. Thus, while neutralizing antibodies are the best correlate of protection, non-neutralizing antibodies can also be protective. This should be taken into consideration in future avian influenza vaccine trials. PMID:28303960

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

    PubMed

    Cecchi, Giuliano; Ilemobade, Albert; Le Brun, Yvon; Hogerwerf, Lenny; Slingenbergh, Jan

    2008-11-01

    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.

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

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

    2011-08-07

    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.

  5. Identifying live bird markets with the potential to act as reservoirs of avian influenza A (H5N1) virus: a survey in northern Viet Nam and Cambodia.

    PubMed

    Fournié, Guillaume; Guitian, Javier; Desvaux, Stéphanie; Mangtani, Punam; Ly, Sowath; Cong, Vu Chi; San, Sorn; Dung, Do Huu; Holl, Davun; Pfeiffer, Dirk U; Vong, Sirenda; Ghani, Azra C

    2012-01-01

    Wet markets are common in many parts of the world and may promote the emergence, spread and maintenance of livestock pathogens, including zoonoses. A survey was conducted in order to assess the potential of Vietnamese and Cambodian live bird markets (LBMs) to sustain circulation of highly pathogenic avian influenza virus subtype H5N1 (HPAIV H5N1). Thirty Vietnamese and 8 Cambodian LBMs were visited, and structured interviews were conducted with the market managers and 561 Vietnamese and 84 Cambodian traders. Multivariate and cluster analysis were used to construct a typology of traders based on their poultry management practices. As a result of those practices and large poultry surplus (unsold poultry reoffered for sale the following day), some poultry traders were shown to promote conditions favorable for perpetuating HPAIV H5N1 in LBMs. More than 80% of these traders operated in LBMs located in the most densely populated areas, Ha Noi and Phnom Penh. The profiles of sellers operating at a given LBM could be reliably predicted using basic information about the location and type of market. Consequently, LBMs with the largest combination of risk factors for becoming virus reservoirs could be easily identified, potentially allowing control strategies to be appropriately targeted. These findings are of particular relevance to resource-scarce settings with extensively developed LBM systems, commonly found in South-East Asia.

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

    USGS Publications Warehouse

    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.

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

    PubMed

    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.

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

    PubMed

    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.

  9. Role of wild birds in the spread of highly pathogenic avian influenza virus H5N1 and implications for global surveillance.

    PubMed

    Feare, Chris J

    2010-03-01

    This paper reviews outbreaks of Asian-lineage highly pathogenic avian influenza virus (HPAIV) H5N1 in wild birds since June 2006, surveillance strategies, and research on virus epidemiology in wild birds to summarize advances in understanding the role of wild birds in the spread of HPAIV H5N1 and the risk that infected wild birds pose for the poultry industry and for public health. Surveillance of apparently healthy wild birds ("active" surveillance) has not provided early warning of likely infection for the poultry industry, whereas searches for and reports of dead birds ("passive" surveillance) have provided evidence of environmental presence of the virus, but not necessarily its source. Most outbreaks in wild birds have occurred during periods when they are experiencing environmental, physiologic, and possibly psychological stress, including adverse winter weather and molt, but not, apparently, long-distance migration. Examination of carcasses of infected birds and experimental challenge with strains of HPAIV H5N1 have provided insight into the course of infection, the extent of virus shedding, and the relative importance of cloacal vs. oropharyngeal excretion. Satellite telemetry of migrating birds is now providing data on the routes taken by individual birds, their speed of migration, and the duration of stopovers. It is still not clear how virus shedding during the apparently clinically silent phase of infection relates to the distance travelled by infected birds. Mounting an immune response and undertaking strenuous exercise associated with long migratory flights may be competitive. This is an area where further research should be directed in order to discover whether wild birds infected with HPAIV H5N1 are able or willing to embark on migration.

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

    PubMed Central

    Thanapongtharm, Weerapong; Van Boeckel, Thomas P.; Biradar, Chandrashekhar; Xiao, Xiangming; Gilbert, Marius

    2016-01-01

    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 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. PMID:24258895

  11. Genetics and infectivity of H5N1 highly pathogenic avian influenza viruses isolated from chickens and wild birds in Japan during 2010-11.

    PubMed

    Uchida, Yuko; Suzuki, Yasushi; Shirakura, Masayuki; Kawaguchi, Akira; Nobusawa, Eri; Tanikawa, Taichiro; Hikono, Hirokazu; Takemae, Nobuhiro; Mase, Masaji; Kanehira, Katsushi; Hayashi, Tsuyoshi; Tagawa, Yuichi; Tashiro, Masato; Saito, Takehiko

    2012-12-01

    Outbreaks of H5N1 subtype highly pathogenic avian influenza virus (HPAIV) were recorded in chickens, domesticated birds and wild birds throughout Japan from November 2010 to March 2011. Genetic analysis of the Japanese isolates indicated that all gene segments, except the PA gene, were closely related to Japanese wild bird isolates in 2008 and belonged to clade 2.3.2.1 classified by the WHO/OIE/FAO H5N1 Evolution Working Group. Direct ancestors of the PA gene segment of all Japanese viruses analyzed in this study can be found in wild bird strains of several subtypes other than H5N1 isolated between 2007 and 2009. The PA gene of these wild bird isolates share a common ancestor with H5N1 HPAIVs belonging to clades 2.5, 7 and 9, indicating that wild birds were involved in the emergence of the current reassortant 2.3.2.1 viruses. To determine how viruses were maintained in the wild bird population, two isolates derived from chickens (A/chicken/Shimane/1/2010, Ck10 and A/chicken/Miyazaki/S4/2011, CkS411) and one from a wild bird (A/mandarin duck/Miyazaki/22M-765/2011, MandarinD11) were compared in their ability to infect and be transmitted to chickens. There was a significant difference in the survival of chickens that were infected with 10(6)EID(50) of CkS411 compared to those with MandarinD11 and the transmission efficiency of CkS411 was greater than the other viruses. The increased titer of CkS411 excreted from infected chickens contributed to the improved transmission rates. It was considered that reduced virus excretion and transmission of MandarinD11 could have been due to adaptation of the virus in wild birds.

  12. The epidemiology of the highly pathogenic H5N1 avian influenza in Mute Swan (Cygnus olor) and other Anatidae in the Dombes region (France), 2006.

    PubMed

    Hars, Jean; Ruette, Sandrine; Benmergui, Maurice; Fouque, Carol; Fournier, Jean-Yves; Legouge, Arnaud; Cherbonnel, Martine; Daniel, Baroux; Dupuy, Catherine; Jestin, Véronique

    2008-10-01

    In February 2006, a highly pathogenic avian influenza (HPAI) H5N1 virus was isolated from Common Pochards (Aythia ferina) in the Dombes region of France, an important migrating and wintering waterfowl area. Thereafter, HPAI H5N1 virus was isolated from 39 swab pools collected from dead waterfowl found in the Dombes, but only from three pooled samples collected outside of this area but located on the same migration flyway. A single turkey farm was infected in the Dombes. The epizootic lasted 2 mo and was restricted to the Dombes area. Virus-positive pools were detected in 20 of 1,200 ponds and infected Mute Swans (Cygnus olor) represented 82% of the virus-positive pools. Other infected species included Common Pochard (n=4), Grey Heron (Ardea cinerea, n=1), Eurasian Buzzard (Buteo buteo, n=1), and Greylag Goose (Anser anser, n=1). Despite intensive monitoring during and after the outbreak, HPAI H5N1 virus was not isolated from healthy wild birds. Our results are consistent with an HPAI H5N1-virus introduction into the Dombes via migrating ducks. These birds could have been pushed west by a severe cold spell in central Europe where the virus had already been detected. The Mute Swan served as an excellent epidemiologic sentinel during this outbreak; swans appear to be highly sensitive to infection with these viruses and swan mortality was easy to detect. During the outbreak, the mortality rates for wild birds remained moderate and the virus affected a limited number of species.

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

    PubMed

    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.

  14. Highly (H5N1) and Low (H7N2) Pathogenic Avian Influenza Virus Infection in Falcons Via Nasochoanal Route and Ingestion of Experimentally Infected Prey

    PubMed Central

    Bertran, Kateri; Busquets, Núria; Abad, Francesc Xavier; García de la Fuente, Jorge; Solanes, David; Cordón, Iván; Costa, Taiana; Dolz, Roser; Majó, Natàlia

    2012-01-01

    An experimental infection with highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI) viruses was carried out on falcons in order to examine the effects of these viruses in terms of pathogenesis, viral distribution in tissues and viral shedding. The distribution pattern of influenza virus receptors was also assessed. Captive-reared gyr-saker (Falco rusticolus x Falco cherrug) hybrid falcons were challenged with a HPAI H5N1 virus (A/Great crested grebe/Basque Country/06.03249/2006) or a LPAI H7N2 virus (A/Anas plathyrhynchos/Spain/1877/2009), both via the nasochoanal route and by ingestion of previously infected specific pathogen free chicks. Infected falcons exhibited similar infection dynamics despite the different routes of exposure, demonstrating the effectiveness of in vivo feeding route. H5N1 infected falcons died, or were euthanized, between 5–7 days post-infection (dpi) after showing acute severe neurological signs. Presence of viral antigen in several tissues was confirmed by immunohistochemistry and real time RT-PCR (RRT-PCR), which were generally associated with significant microscopical lesions, mostly in the brain. Neither clinical signs, nor histopathological findings were observed in any of the H7N2 LPAI infected falcons, although all of them had seroconverted by 11 dpi. Avian receptors were strongly present in the upper respiratory tract of the falcons, in accordance with the consistent oral viral shedding detected by RRT-PCR in both H5N1 HPAI and H7N2 LPAI infected falcons. The present study demonstrates that gyr-saker hybrid falcons are highly susceptible to H5N1 HPAI virus infection, as previously observed, and that they may play a major role in the spreading of both HPAI and LPAI viruses. For the first time in raptors, natural infection by feeding on infected prey was successfully reproduced. The use of avian prey species in falconry husbandry and wildlife rehabilitation facilities could put valuable birds of prey

  15. Role of different genes in the pathogenesis of H5N1 Avian Influenza Virus in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The determinants of pathogenicity of Avian Influenza (AI) virus are not totally defined. Previous studies have pointed towards the importance of different influenza virus genes in determining virulence in various hosts. We used reverse genetics to generate recombinant viruses in order to better unde...

  16. NS1 gene truncations partially attenuate H5N1 highly pathogenic avian influenza viruses in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The polybasic amino acid sequence in the hemagglutinin (HA) protein of H5 and H7 avian influenza (AI) viruses determines the high pathogenicity (HP) phenotype in chickens. The NS1 protein plays an important role in blocking the induction of antiviral defenses and other regulatory functions and thus...

  17. Susceptibility to and transmission of H5N1 and H7N1 highly pathogenic avian influenza viruses in bank voles (Myodes glareolus).

    PubMed

    Romero Tejeda, Aurora; Aiello, Roberta; Salomoni, Angela; Berton, Valeria; Vascellari, Marta; Cattoli, Giovanni

    2015-05-13

    The study of influenza type A (IA) infections in wild mammals populations is a critical gap in our knowledge of how IA viruses evolve in novel hosts that could be in close contact with avian reservoir species and other wild animals. The aim of this study was to evaluate the susceptibility to infection, the nasal shedding and the transmissibility of the H7N1 and H5N1 highly pathogenic avian influenza (HPAI) viruses in the bank vole (Myodes glareolus), a wild rodent common throughout Europe and Asia. Two out of 24 H5N1-infected voles displayed evident respiratory distress, while H7N1-infected voles remained asymptomatic. Viable virus was isolated from nasal washes collected from animals infected with both HPAI viruses, and extra-pulmonary infection was confirmed in both experimental groups. Histopathological lesions were evident in the respiratory tract of infected animals, although immunohistochemistry positivity was only detected in lungs and trachea of two H7N1-infected voles. Both HPAI viruses were transmitted by direct contact, and seroconversion was confirmed in 50% and 12.5% of the asymptomatic sentinels in the H7N1 and H5N1 groups, respectively. Interestingly, viable virus was isolated from lungs and nasal washes collected from contact sentinels of both groups. The present study demonstrated that two non-rodent adapted HPAI viruses caused asymptomatic infection in bank voles, which shed high amounts of the viruses and were able to infect contact voles. Further investigations are needed to determine whether bank voles could be involved as silent hosts in the transmission of HPAI viruses to other mammals and domestic poultry.

  18. Impact of vaccination on infection with Vietnam H5N1 high pathogenicity avian influenza virus in hens and the eggs they lay.

    PubMed

    Bertran, Kateri; Moresco, Kira; Swayne, David E

    2015-03-10

    High pathogenicity avian influenza virus (HPAIV) infections in chickens negatively impact egg production and cause egg contamination. Previously, vaccination maintained egg production and reduced egg contamination when challenged with a North American H5N2 HPAIV. However, Asian H5N1 HPAIV infection has some characteristics of increased pathogenicity compared to other H5 HPAIV such as more rapid drop and complete cessation in egg production. Sham (vaccinated at 25 and 28 weeks of age), inactivated H5N1 Once (1X-H5-Vax; vaccinated at 28 weeks of age only) and inactivated H5N1 Twice (2X-H5-Vax; vaccinated at 25 and 28 weeks of age) vaccinated adult White Leghorn hens were challenged intranasally at 31 weeks of age with 6.1 log10 mean embryo infectious doses (EID50) of clade 2.3.2.1a H5N1 HPAIV (A/chicken/Vietnam/NCVD-675/2011) which was homologous to the inactivated vaccine. Sham-vaccinated layers experienced 100% mortality within 3 days post-challenge; laid soft and thin-shelled eggs; had recovery of virus from oral swabs and in 53% of the eggs from eggshell surface (35%), yolk (24%), and albumin (41%); and had very high titers of virus (average 7.91 log10 EID50/g) in all segments of the oviduct and ovary. By comparison, 1X- and 2X-H5-Vax challenged hens survived infection, laid similar number of eggs pre- and post-challenge, all eggs had normal egg shell quality, and had significantly fewer contaminated eggs with reduced virus quantity. The 2X-H5-Vax hens had significantly higher HI titers by the day of challenge (304 GMT) and at termination (512 GMT) than 1X-H5-Vax hens (45 GMT and 128 GMT). The current study demonstrated that AIV infections caused by clade 2.3.2.1a H5N1 variants can be effectively controlled by either double or single homologous vaccination.

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

    PubMed Central

    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

  20. Antibody titer has positive predictive value for vaccine protection against challenge with natural antigenic-drift variants of H5N1 high-pathogenicity avian influenza viruses from Indonesia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beginning with Hong Kong in 2002, vaccines have been used as part of an integrated control strategy in 14 countries/regions to protect poultry against H5N1 high pathogenicity avian influenza (HPAI). H5N1 HPAI was first reported in Indonesia in 2003 and vaccination was initiated the following year. ...

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

    PubMed

    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. Differential host gene expression in cells infected with highly pathogenic H5N1 avian influenza viruses.

    PubMed

    Sarmento, Luciana; Afonso, Claudio L; Estevez, Carlos; Wasilenko, Jamie; Pantin-Jackwood, Mary

    2008-10-15

    In order to understand the molecular mechanisms by which different strains of avian influenza viruses overcome host response in birds, we used a complete chicken genome microarray to compare early gene expression levels in chicken embryo fibroblasts (CEF) infected with two avian influenza viruses (AIV), A/CK/Hong Kong/220/97 and A/Egret/Hong Kong/757.2/02, with different replication characteristics. Gene ontology revealed that the genes with altered expression are involved in many vital functional classes including protein metabolism, translation, transcription, host defense/immune response, ubiquitination and the cell cycle. Among the immune-related genes, MEK2, MHC class I, PDCD10 and Bcl-3 were selected for further expression analysis at 24 hpi using semi-quantitive RT-PCR. Infection of CEF with A/Egret/Hong Kong/757.2/02 resulted in a marked repression of MEK2 and MHC class I gene expression levels. Infection of CEF with A/CK/Hong Kong/220/97 induced an increase of MEK2 and a decrease in PDCD10 and Bcl-3 expression levels. The expression levels of alpha interferon (IFN-alpha), myxovirus resistance 1 (Mx1) and interleukin-8 (IL-8) were also analyzed at 24 hpi, showing higher expression levels of all of these genes after infection with A/CK/Hong Kong/220/97 compared to A/Egret/Hong Kong/757.2/02. In addition, comparison of the NS1 sequences of the viruses revealed amino acid differences that may explain in part the differences in IFN-alpha expression observed. Microarray gene expression analysis has proven to be a useful tool on providing important insights into how different AIVs affect host gene expression and how AIVs may use different strategies to evade host response and replicate in host cells.

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

    PubMed

    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.

  4. Epidemiological and ornithological aspects of outbreaks of highly pathogenic avian influenza virus H5N1 of Asian lineage in wild birds in Germany, 2006 and 2007.

    PubMed

    Globig, A; Staubach, C; Beer, M; Köppen, U; Fiedler, W; Nieburg, M; Wilking, H; Starick, E; Teifke, J P; Werner, O; Unger, F; Grund, C; Wolf, C; Roost, H; Feldhusen, F; Conraths, F J; Mettenleiter, T C; Harder, T C

    2009-04-01

    In Germany, two distinct episodes of outbreaks of highly pathogenic avian influenza virus of subtype H5N1 (HPAIV H5N1) in wild birds occurred at the beginning of 2006, and in summer 2007. High local densities of wild bird populations apparently sparked clinically detectable outbreaks. However, these remained restricted in (i) number of birds, (ii) species found to be affected, (iii) time, and (iv) location despite the presence of several hundred thousands of susceptible wild birds and further stressors (food shortage, harsh weather conditions and moulting). Northern and southern subpopulations of several migratory anseriform species can be distinguished with respect to their preference for wintering grounds in Germany. This corroborates viral genetic data by Starick et al. (2008) demonstrating the introduction of two geographically restricted virus subpopulations of Qinghai-like lineage (cluster 2.2.A and 2.2.B) into northern and southern Germany, respectively, in 2006. The incursion of virus emerging in 2007, found to be distinct from the clusters detected in 2006 (Starick et al., 2008), may have been associated with moulting movements. Intensive past-outbreak investigations with negative results of live and dead wild birds and of terrestrial scavengers excluded continued circulation of virus on a larger scale. However, persistence of virus in small pockets of local wild bird populations could not be ruled out resiliently. 1.5% of investigated sera originating from cats sampled at the epicentres of the Ruegen 2006-outbreak contained H5-antibodies. Passive monitoring was found to be highly superior to live bird surveillance when aiming at the detection of HPAIV H5N1 in wild birds (P < 0.0001).

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

    PubMed

    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.

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

    PubMed

    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.

  7. Antibody Persistence and Booster Responses to Split-Virion H5N1 Avian Influenza Vaccine in Young and Elderly Adults

    PubMed Central

    Lazarus, Rajeka; Kelly, Sarah; Snape, Matthew D.; Vandermeulen, Corinne; Voysey, Merryn; Hoppenbrouwers, Karel; Hens, Annick; Van Damme, Pierre; Pepin, Stephanie; Leroux-Roels, Isabel; Leroux-Roels, Geert; Pollard, Andrew J.

    2016-01-01

    Avian influenza continues to circulate and remains a global health threat not least because of the associated high mortality. In this study antibody persistence, booster vaccine response and cross-clade immune response between two influenza A(H5N1) vaccines were compared. Participants aged over 18-years who had previously been immunized with a clade 1, A/Vietnam vaccine were re-immunized at 6-months with 7.5 μg of the homologous strain or at 22-months with a clade 2, alum-adjuvanted, A/Indonesia vaccine. Blood sampled at 6, 15 and 22-months after the primary course was used to assess antibody persistence. Antibody concentrations 6-months after primary immunisation with either A/Vietnam vaccine 30 μg alum-adjuvanted vaccine or 7.5 μg dose vaccine were lower than 21-days after the primary course and waned further with time. Re-immunization with the clade 2, 30 μg alum-adjuvanted vaccine confirmed cross-clade reactogenicity. Antibody cross-reactivity between A(H5N1) clades suggests that in principle a prime-boost vaccination strategy may provide both early protection at the start of a pandemic and improved antibody responses to specific vaccination once available. Trial Registration: ClinicalTrials.gov NCT00415129 PMID:27814377

  8. Global mapping of highly pathogenic avian influenza H5N1 and H5Nx clade 2.3.4.4 viruses with spatial cross-validation

    PubMed Central

    Dhingra, Madhur S; Artois, Jean; Robinson, Timothy P; Linard, Catherine; Chaiban, Celia; Xenarios, Ioannis; Engler, Robin; Liechti, Robin; Kuznetsov, Dmitri; Xiao, Xiangming; Dobschuetz, Sophie Von; Claes, Filip; Newman, Scott H; Dauphin, Gwenaëlle; Gilbert, Marius

    2016-01-01

    Global disease suitability models are essential tools to inform surveillance systems and enable early detection. We present the first global suitability model of highly pathogenic avian influenza (HPAI) H5N1 and demonstrate that reliable predictions can be obtained at global scale. Best predictions are obtained using spatial predictor variables describing host distributions, rather than land use or eco-climatic spatial predictor variables, with a strong association with domestic duck and extensively raised chicken densities. Our results also support a more systematic use of spatial cross-validation in large-scale disease suitability modelling compared to standard random cross-validation that can lead to unreliable measure of extrapolation accuracy. A global suitability model of the H5 clade 2.3.4.4 viruses, a group of viruses that recently spread extensively in Asia and the US, shows in comparison a lower spatial extrapolation capacity than the HPAI H5N1 models, with a stronger association with intensively raised chicken densities and anthropogenic factors. DOI: http://dx.doi.org/10.7554/eLife.19571.001 PMID:27885988

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

    PubMed

    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.

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

    PubMed Central

    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

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

    PubMed

    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.

  12. Overview of incursions of Asian H5N1 subtype highly pathogenic avian influenza virus into Great Britain, 2005-2008.

    PubMed

    Alexander, Dennis J; Manvell, Ruth J; Irvine, Richard; Londt, Brandon Z; Cox, Bill; Ceeraz, Vanessa; Banks, Jill; Browna, Ian H

    2010-03-01

    Since 2005 there have been five incursions into Great Britain of highly pathogenic avian influenza (HPAI) viruses of subtype H5N1 related to the ongoing global epizootic. The first incursion occurred in October 2005 in birds held in quarantine after importation from Taiwan. Two incursions related to wild birds: one involved a single dead whooper swan found in March 2006 in the sea off the east coast of Scotland, and the other involved 10 mute swans and a Canada goose found dead over the period extending from late December 2007 to late February 2008 on or close to a swannery on the south coast of England. The other two outbreaks occurred in commercial poultry in January 2007 and November 2007, both in the county of Suffolk. The first of these poultry outbreaks occurred on a large turkey farm, and there was no further spread. The second outbreak occurred on a free-range farm rearing turkeys, ducks, and geese and spread to birds on a second turkey farm that was culled as a dangerous contact. Viruses isolated from these five outbreaks were confirmed to be Asian H5N1 HPAI viruses; the quarantine outbreak was attributed to a clade 2.3 virus and the other four to clade 2.2 viruses. This article describes the outbreaks, their control, and the possible origins of the responsible viruses.

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

    PubMed Central

    Rousou, Xanthoula; Kalthoff, Donata; Beer, Martin

    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. PMID:26763336

  14. Post-exposure treatment with whole inactivated H5N1 avian influenza virus protects against lethal homologous virus infection in mice

    PubMed Central

    Hagan, Mable; Ranadheera, Charlene; Audet, Jonathan; Morin, Jocelyn; Leung, Anders; Kobasa, Darwyn

    2016-01-01

    Concerns with H5N1 influenza viruses include their prevalence in wild and domestic poultry, high mortality rate (~60%) in humans with some strains, lack of pre-existing immunity in humans, and the possibility that these viruses acquire mutations that enable efficient transmission between humans. H5 subtype viruses of Eurasian origin have recently appeared in wild and domestic bird populations in North America, and have led to the generation of new virus strains that are highly pathogenic in poultry. These new H5 HA containing viruses with their ability to evolve rapidly represent an unknown threat to humans in contact with infected poultry, and vaccination with an off-the-shelf vaccine may be impractical to provide protection to at-risk individuals. Instead, we have evaluated the efficacy of a formalin-inactivated vaccine, which could be derived directly from a circulating virus, to provide post-exposure protection. This strategy was evaluated using a prototypic highly pathogenic avian H5N1 strain, A/Vietnam/1203/2004, and demonstrated rapid induction of adaptive immune responses providing protection in a mammalian model of lethal infection. Additionally, this post-exposure vaccine was highly efficacious when administered 24 hours after exposure. This study offers a platform for developing effective post-exposure vaccines for treatment of highly virulent influenza infections. PMID:27405487

  15. The Effect of the PB2 Mutation 627K on Highly Pathogenic H5N1 Avian Influenza Virus Is Dependent on the Virus Lineage

    PubMed Central

    Howard, Wendy A.; Núñez, Alejandro; Moncorgé, Olivier; Lycett, Samantha; Banks, Jill

    2013-01-01

    Clade 2.2 Eurasian-lineage H5N1 highly pathogenic avian influenza viruses (HPAIVs) were first detected in Qinghai Lake, China, in 2005 and subsequently spread through Asia, Europe, and Africa. Importantly, these viruses carried a lysine at amino acid position 627 of the PB2 protein (PB2 627K), a known mammalian adaptation motif. Previous avian influenza virus isolates have carried glutamic acid in this position (PB2 627E), commonly described to restrict virus polymerase function in the mammalian host. We sought to examine the effect of PB2 627K on viral maintenance in the avian reservoir. Viruses constructed by reverse genetics were engineered to contain converse PB2 627K/E mutations in a Eurasian H5N1 virus (A/turkey/Turkey/5/2005 [Ty/05]) and, for comparison, a historical pre-Asian H5N1 HPAIV that naturally bears PB2 627E (A/turkey/England/50-92/1991 [50-92]). The 50-92 PB2 627K was genetically unstable during virus propagation, resulting in reversion to PB2 627E or the accumulation of the additional mutation PB2 628R and/or a synonymous mutation from an A to a G nucleotide at nucleotide position 1869 (PB2 A1869G). Intriguingly, PB2 628R and/or A1869G appeared to improve the genetic stability of 50-92 PB2 627K. However, the replication of 50-92 PB2 627K in conjunction with these stabilizing mutations was significantly restricted in experimentally infected chickens, where reversion to PB2 627E occurred. In contrast, no significant effects on viral fitness were observed for Ty/05 PB2 627E or 627K in in vitro or in vivo experiments. Our observations suggest that PB2 627K is supported in Eurasian-lineage viruses; in contrast, PB2 627K carries a significant fitness cost in the historical pre-Asian 50-92 virus. PMID:23843645

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed Central

    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

  19. Experimental infection of Muscovy ducks with highly pathogenic avian influenza virus (H5N1) belonging to clade 2.2.

    PubMed

    Guionie, Olivier; Guillou-Cloarec, Cécile; Courtois, David; Bougeard, B Stéphanie; Amelot, Michel; Jestin, Véronique

    2010-03-01

    Highly pathogenic (HP) H5N1 avian influenza (AI) is enzootic in several countries of Asia and Africa and constitutes a major threat, at the world level, for both animal and public health. Ducks play an important role in the epidemiology of AI, including HP H5N1 AI. Although vaccination can be a useful tool to control AI, duck vaccination has not proved very efficient in the field, indicating a need to develop new vaccines and a challenge model to evaluate the protection for duck species. Although Muscovy duck is the duck species most often reared in France, the primary duck-producing country in Europe, and is also produced in Asia, it is rarely studied. Our team recently demonstrated a good cross-reactivity with hemagglutinin from clade 2.2 and inferred that this could be a good vaccine candidate for ducks. Two challenges using two French H5N1 HP strains, 1) A/mute swan/France/06299/06 (Swan/06299), clade 2.2.1, and 2) A/mute swan/France/070203/07 (Swan/070203), clade 2.2 (but different from subclade 2.2.1), were performed (each) on 20 Muscovy ducks (including five contacts) inoculated by oculo-nasal route (6 log10 median egg infectious doses per duck). Clinical signs were recorded daily, and cloacal and oropharyngeal swabs were collected throughout the assay. Autopsies were done on all dead ducks, and organs were taken for analyses. Virus was measured by quantitative reverse transcriptase-PCR based on the M gene AI virus. Ducks presented severe nervous signs in both challenges. Swan/070203 strain led to 80% morbidity (12/15 sick ducks) and 73% mortality (11/15 ducks) at 13.5 days postinfection (dpi), whereas Swan/06299 strain produced 100% mortality at 6.5 dpi. Viral RNA load was significantly lower via the cloacal route than via the oropharyngeal route in both trials, presenting a peak in the first challenge at 3.5 dpi and being more stable in the second challenge. The brain was the organ containing the highest viral RNA load in both challenges. Viral RNA load in

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

    PubMed

    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

  1. Genetic analysis of avian influenza A viruses isolated from domestic waterfowl in live-bird markets of Hanoi, Vietnam, preceding fatal H5N1 human infections in 2004.

    PubMed

    Jadhao, Samadhan J; Nguyen, Doan C; Uyeki, Timothy M; Shaw, Michael; Maines, Taronna; Rowe, Thomas; Smith, Catherine; Huynh, Lien P T; Nghiem, Ha K; Nguyen, Diep H T; Nguyen, Hang K L; Nguyen, Hanh H T; Hoang, Long T; Nguyen, Tung; Phuong, Lien S; Klimov, Alexander; Tumpey, Terrence M; Cox, Nancy J; Donis, Ruben O; Matsuoka, Yumiko; Katz, Jacqueline M

    2009-01-01

    The first known cases of human infection with highly pathogenic avian influenza (HPAI) H5N1 viruses in Vietnam occurred in late 2003. However, HPAI H5N1 and low-pathogenic avian influenza (LPAI) H5N2 and H9N3 viruses were isolated from domestic waterfowl during live-bird market (LBM) surveillance in Vietnam in 2001 and 2003. To understand the possible role of these early viruses in the genesis of H5N1 strains infecting people, we performed sequencing and molecular characterization. Phylogenetic analysis revealed that the hemagglutinin (HA) genes of two geese HPAI H5N1 strains belonged to clade 3, and their surface glycoprotein and replication complex genes were most closely related (98.5-99.7% homologous) to A/duck/Guangxi/22/01 (H5N1) virus, detected contemporarily in southern China, whilst the M and NS genes were derived from an A/duck/Hong Kong/2986.1/00 (H5N1)-like virus. The H5 HA gene of the duck HPAI H5N1 strain belonged to clade 5 and acquired a gene constellation from A/quail/Shantou/3846/02 (H5N1), A/teal/China/2978.1/02 (H5N1) and A/partridge/Shantou/2286/03 (H5N1)-like viruses. The phylogenetic analysis further indicated that all eight gene segments of goose and duck HPAI H5N1 and LPAI H5N2 viruses were distinct from those of H5N1 clade-1 viruses known to have caused fatal human infections in Vietnam since late 2003. The duck H9N3 isolates derived genes from aquatic-bird influenza viruses, and their H9 HA belonged to the Korean lineage. The PB2 gene of A/duck/Vietnam/340/01 (H9N3) virus had lysine at position 627. Based on the molecular characterization of specific amino acid residues in the surface and relevant internal protein-coding genes, the Vietnamese H5N1 and H9N3 virus isolates indicated specificity to avian cell surface receptor and susceptibility for currently licensed anti-influenza A virus chemotherapeutics. Our findings suggest that the H5N1 and H5N2 viruses that circulated among geese and ducks in LBMs in Hanoi, Vietnam, during 2001 and

  2. A(H5N1) Virus Evolution in South East Asia

    PubMed Central

    Gutiérrez, Ramona Alikiiteaga; Naughtin, Monica Jane; Horm, Srey Viseth; San, Sorn; Buchy, Philippe

    2009-01-01

    Highly Pathogenic Avian Influenza (HPAI) H5N1 virus is an ongoing public health and socio-economic challenge, particularly in South East Asia. H5N1 is now endemic in poultry in many countries, and represents a major pandemic threat. Here, we describe the evolution of H5N1 virus in South East Asia, the reassortment events leading to high genetic diversity in the region, and factors responsible for virus spread. The virus has evolved with genetic variations affecting virulence, drug-resistance, and adaptation to new host species. The constant surveillance of these changes is of primary importance in the global efforts of the scientific community. PMID:21994553

  3. Prevalence and distribution of avian influenza a(H5N1) virus clade variants in live bird markets of Vietnam, 2011-2013.

    PubMed

    Nguyen, Diep T; Bryant, Juliet E; Davis, C Todd; Nguyen, Long V; Pham, Long T; Loth, Leo; Inui, Ken; Nguyen, Tung; Jang, Yunho; To, Thanh L; Nguyen, Tho D; Hoang, Diep T; Do, Hoa T; Nguyen, Trang T; Newman, Scott; Jennifer Siembieda; Pham, Dong V

    2014-12-01

    Active surveillance for avian influenza (Al) viruses in poultry sold at live bird markets (LBMs) was conducted in 44 of 63 provinces throughout Vietnam over two periods from September 2011 to February 2012 and October 2012 to June 2013. The study objectives were to assess the prevalence of avian influenza type A, H5, and H5N1 subtype viruses and characterize the geographical and temporal distribution of H5N1 virus genetic variants across the country. Monthly sampling was conducted in 394 LBMs located in 372 communes. A total of 9790 oropharyngeal swabs from poultry were screened for influenza A virus by real-time reverse-transcriptase PCR Virus isolation was attempted on all positive samples in embryonated chicken eggs, and the HA1 region of each H5 virus isolate was sequenced. Market prevalence of H5 subtype virus was 32.2% (127/394) over the cumulative 15 mo of surveillance. Phylogenetic analyses indicated that clade 1.1 viruses persisted in the south, whereas three genetically distinct subgroups of dade 2.3.2.1 were found simultaneously in northern, central, and southern Vietnam. Clade 2.3.2.1c viruses first appeared in July 2012 and spread rapidly to the center and south of Vietnam in late 2012, where they were predominant among clade 2.3.2.1 viruses and were detected in both active LBM surveillance and poultry outbreaks. Given the overlapping geographic distribution of dade variants and the antigenic divergence previously described for these dades, current AI poultry vaccines used in Vietnam may require bivalent formulations containing representatives of both dade 1.1 and dade 2.3.2.1 viruses.

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

    PubMed

    Gilbert, Martin; Koel, Björn F; Bestebroer, Theo M; Lewis, Nicola S; Smith, Derek J; Fouchier, Ron A M

    2014-01-01

    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.

  5. Serological Evidence for Non-Lethal Exposures of Mongolian Wild Birds to Highly Pathogenic Avian Influenza H5N1 Virus

    PubMed Central

    Gilbert, Martin; Koel, Björn F.; Bestebroer, Theo M.; Lewis, Nicola S.; Smith, Derek J.; Fouchier, Ron A. M.

    2014-01-01

    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. PMID:25502318

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

    PubMed

    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.

  7. A vaccine prepared from a non-pathogenic H5N1 influenza virus strain from the influenza virus library conferred protective immunity to chickens against the challenge with antigenically drifted highly pathogenic avian influenza virus.

    PubMed

    Samad, Rozanah Asmah Abdul; Nomura, Naoki; Tsuda, Yoshimi; Manzoor, Rashid; Kajihara, Masahiro; Tomabechi, Daisuke; Sasaki, Takashi; Kokumai, Norihide; Ohgitani, Toshiaki; Okamatsu, Masatoshi; Takada, Ayato; Sakoda, Yoshihiro; Kida, Hiroshi

    2011-02-01

    Inactivated influenza virus vaccine prepared from a non-pathogenic influenza virus strain A/duck/Hokkaido/Vac-1/2004 (H5N1) from the virus library conferred protective immunity to chickens against the challenge of antigenically drifted highly pathogenic avian influenza virus (HPAIV), A/whooper swan/Hokkaido/1/2008 (H5N1). The efficacy of the vaccine was comparable to that prepared from genetically modified HPAIV strain deltaRRRRK rg-A/ whooper swan/Mongolia/3/2005 (H5N1), which is more antigenically related to the challenge virus strain, in chickens.

  8. Receptor recognition mechanism of human influenza A H1N1 (1918), avian influenza A H5N1 (2004), and pandemic H1N1 (2009) neuraminidase.

    PubMed

    Jongkon, Nipa; Sangma, Chak

    2012-01-01

    Influenza A neuraminidase (NA) is a target for anti-influenza drugs. The function of this enzyme is to cleave a glycosidic linkage of a host cell receptor that links sialic acid (Sia) to galactose (Gal), to allow the virus to leave an infected cell and propagate. The receptor is an oligosaccharide on the host cell surface. There are two types of oligosaccharide receptor; the first, which is found mainly on avian epithelial cell surfaces, links Sia with Gal by an α2,3 glycosidic linkage; in the second, found mainly on human epithelial cell surfaces, linkage is via an α2,6 linkage. Some researchers believe that NAs from different viruses show selectivity for each type of linkage, but there is limited information available to confirm this hypothesis. To see if the linkage type is more specific to any particular NA, a number of NA-receptor complexes of human influenza A H1N1 (1918), avian influenza A H5N1 (2004), and a pandemic strain of H1N1 (2009) were constructed using homology modeling and molecular dynamics simulation. The results show that the two types of receptor analogues bound to NAs use different mechanisms. Moreover, it was found that a residue unique to avian virus NA is responsible for the recognition of the Siaα2,3Gal receptor, and a residue unique to human virus NA is responsible for the recognition of Siaα2,6Gal. We believe that this finding could explain how NAs of different virus origins always possess some unique residues.

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

    PubMed

    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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 surrogate for humans in influenza pathogenicity a...

  11. Differences in pathogenicity, response to vaccination, and innate immune responses in different types of ducks infected with a virulent H5N1 highly pathogenic avian influenza virus from Vietnam

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild ducks are reservoirs of avian influenza viruses in nature, and usually don’t show signs of disease. However, some Asian lineage H5N1 highly pathogenic avian influenza (HPAI) viruses can cause disease and death in both wild and domestic ducks. The objective of this study was to compare the cli...

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

    PubMed

    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.

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

    PubMed Central

    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. PMID:27078641

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

    PubMed

    Alkhamis, Mohammad A; Moore, Brian R; Perez, Andres M

    2015-06-23

    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.

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

    PubMed Central

    Alkhamis, Mohammad A.; Moore, Brian R.; Perez, Andres M.

    2015-01-01

    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. PMID:26110587

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

    PubMed

    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

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

    USGS Publications Warehouse

    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

    Conclusions Dunlin are highly susceptible to infection with HPAIV H5N1. They become infected after exposure to relatively small doses of the virus and if they become infected, they are most likely to suffer mortality within 3–5 days. These results have important implications regarding the risks of transport and transmission of HPAIV H5N1 to North America by this species and raises questions for further investigation.

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

    PubMed

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

    2010-10-01

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

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

    PubMed

    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.

  20. Tropism and Induction of Cytokines in Human Embryonic-Stem Cells-Derived Neural Progenitors upon Inoculation with Highly- Pathogenic Avian H5N1 Influenza Virus.

    PubMed

    Pringproa, Kidsadagon; Rungsiwiwut, Ruttachuk; Tantilertcharoen, Rachod; Praphet, Reunkeaw; Pruksananonda, Kamthorn; Baumgärtner, Wolfgang; Thanawongnuwech, Roongroje

    2015-01-01

    Central nervous system (CNS) dysfunction caused by neurovirulent influenza viruses is a dreaded complication of infection, and may play a role in some neurodegenerative conditions, such as Parkinson-like diseases and encephalitis lethargica. Although CNS infection by highly pathogenic H5N1 virus has been demonstrated, it is unknown whether H5N1 infects neural progenitor cells, nor whether such infection plays a role in the neuroinflammation and neurodegeneration. To pursue this question, we infected human neural progenitor cells (hNPCs) differentiated from human embryonic stem cells in vitro with H5N1 virus, and studied the resulting cytopathology, cytokine expression, and genes involved in the differentiation. Human embryonic stem cells (BG01) were maintained and differentiated into the neural progenitors, and then infected by H5N1 virus (A/Chicken/Thailand/CUK2/04) at a multiplicity of infection of 1. At 6, 24, 48, and 72 hours post-infection (hpi), cytopathic effects were observed. Then cells were characterized by immunofluorescence and electron microscopy, supernatants quantified for virus titers, and sampled cells studied for candidate genes.The hNPCs were susceptible to H5N1 virus infection as determined by morphological observation and immunofluorescence. The infection was characterized by a significant up-regulation of TNF-α gene expression, while expressions of IFN-α2, IFN-β1, IFN-γ and IL-6 remained unchanged compared to mock-infected controls. Moreover, H5N1 infection did not appear to alter expression of neuronal and astrocytic markers of hNPCs, such as β-III tubulin and GFAP, respectively. The results indicate that hNPCs support H5N1 virus infection and may play a role in the neuroinflammation during acute viral encephalitis.

  1. Comparative epidemiology of human infections with avian influenza A(H7N9) and A(H5N1) viruses in China

    PubMed Central

    Cowling, Benjamin J.; Jin, Lianmei; Lau, Eric H. Y.; Liao, Qiaohong; Wu, Peng; Jiang, Hui; Tsang, Tim K.; Zheng, Jiandong; Fang, Vicky J.; Chang, Zhaorui; Ni, Michael Y.; Zhang, Qian; Ip, Dennis K. M.; Yu, Jianxing; Li, Yu; Wang, Liping; Tu, Wenxiao; Meng, Ling; Wu, Joseph T.; Luo, Huiming; Li, Qun; Shu, Yuelong; Li, Zhongjie; Feng, Zijian; Yang, Weizhong; Wang, Yu; Leung, Gabriel M.; Yu, Hongjie

    2013-01-01

    Background The novel influenza A(H7N9) virus recently emerged, while influenza A(H5N1) virus has infected humans since 2003 in mainland China. Both infections are thought to be predominantly zoonotic. We compared the epidemiologic characteristics of the complete series of laboratory-confirmed cases of both viruses in mainland China to date. Methods An integrated database was constructed with information on demographic, epidemiological, and clinical variables of laboratory-confirmed A(H7N9) and A(H5N1) cases that were reported to the Chinese Center for Disease Control and Prevention up to May 24, 2013. We described disease occurrence by age, sex and geography and estimated key epidemiologic parameters. Findings Among 130 and 43 patients with confirmed A(H7N9) and A(H5N1) respectively, the median ages were 62y and 26y. In urban areas, 74% of cases of both viruses were male whereas in rural areas the proportions were 62% for A(H7N9) and 33% for A(H5N1). Among cases of A(H7N9) and A(H5N1), 75% and 71% reported recent exposure to poultry. The mean incubation periods of A(H7N9) and A(H5N1) were 3.1 and 3.3 days, respectively. On average, 21 and 18 contacts were traced for each A(H7N9) case in urban and rural areas respectively; compared to 90 and 63 for A(H5N1). The hospitalization fatality risk was 35% (95% CI: 25%, 44%) for A(H7N9) and 70% (95% CI: 56%, 83%) for A(H5N1). Interpretation The sex ratios in urban compared to rural cases are consistent with poultry exposure driving the risk of infection. However the difference in susceptibility to serious illness with the two different viruses remains unexplained, given that most A(H7N9) cases were in older adults while most A(H5N1) cases were in younger individuals. Funding Ministry of Science and Technology, China; Research Fund for the Control of Infectious Disease and University Grants Committee, Hong Kong Special Administrative Region, China; and the US National Institutes of Health. PMID:23803488

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

    PubMed Central

    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

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

    PubMed

    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.

  4. 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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  5. 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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. Variation in protection of four divergent avian influenza virus vaccine seed strains against eight clade 2.2.1 and 2.2.1.1. Egyptian H5N1 high pathogenicity variants in poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic (HP) H5N1 avian influenza virus (AIV) was introduced to Egyptian poultry in 2006 and has since become enzootic. Vaccination has been utilized as a control tool, but for a variety of reasons the disease has not been eradicated. In 2007, an antigenically divergent hemagglutinin sub-c...

  7. Experimental infection of bar-headed geese (Anser indicus) and ruddy shelducks (Tadorna ferruginea) with a clade 2.3.2 H5N1 highly pathogenic avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 2005, clade 2.2 H5N1 highly pathogenic avian influenza (HPAI) viruses have caused infections and disease involving numerous species of wild waterfowl in Eurasia and Africa. However, outbreaks associated with clade 2.3.2 viruses have increased since 2009, and viruses within this clade have beco...

  8. 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)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Goose/Guangdong (Gs/GD)-lineage H5N1 highly pathogenic avian influenza (HPAI) viruses continue to circulate and cause great economic losses in poultry in Asia, the Middle East, and Africa. Recently, the Gs/GD-lineage H5N8 HPAI virus belonging to clade 2.3.4.4 and its reassortants have caused out...

  9. 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

    PubMed Central

    2011-01-01

    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. PMID:21406119

  10. Highly pathogenic avian influenza H5N1 Clade 2.3.2.1c virus in migratory birds, 2014-2015.

    PubMed

    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.

  11. The presence of monocytes enhances the susceptibility of B cells to highly pathogenic avian influenza (HPAI) H5N1 virus possibly through the increased expression of α2,3 SA receptor.

    PubMed

    Lersritwimanmaen, Patharapan; Na-Ek, Prasit; Thanunchai, Maytawan; Thewsoongnoen, Jutarat; Sa-Ard-Iam, Noppadol; Wiboon-ut, Suwimon; Mahanonda, Rangsini; Thitithanyanont, Arunee

    2015-08-28

    The highly pathogenic avian influenza (HPAI) H5N1 virus causes severe systemic infection in avian and mammalian species, including humans by first targeting immune cells. This subsequently renders the innate and adaptive immune responses less active, thus allowing dissemination of the virus to systemic organs. To gain insight into the pathogenesis of H5N1, this study aims to determine the susceptibility of human PBMCs to the H5N1 virus and explore the factors which influence this susceptibility. We found that PBMCs were a target of H5N1 infection, and that monocytes and B cells were populations which were clearly the most susceptible. Analysis of PBMC subpopulations showed that isolated monocytes and monocytes residing in whole PBMCs had comparable percentages of infection (28.97 ± 5.54% vs 22.23 ± 5.14%). In contrast, isolated B cells were infected to a much lower degree than B cells residing in a mixture of whole PBMCs (0.88 ± 0.34% vs 34.87 ± 4.63%). Different susceptibility levels of B cells for these tested conditions spurred us to explore the B cell-H5N1 interaction mechanisms. Here, we first demonstrated that monocytes play a crucial role in the enhancement of B cell susceptibility to H5N1 infection. Although the actual mechanism by which this enhancement occurs remains in question, α2,3-linked sialic acid (SA), known for influenza virus receptors, could be a responsible factor for the greater susceptibility of B cells, as it was highly expressed on the surface of B cells upon H5N1 infection of B cell/monocyte co-cultures. Our findings reveal some of the factors involved with the permissiveness of human immune cells to H5N1 virus and provide a better understanding of the tropism of H5N1 in immune cells.

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

    PubMed Central

    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

  13. Efficacy of single dose of a bivalent vaccine containing inactivated Newcastle disease virus and reassortant highly pathogenic avian influenza H5N1 virus against lethal HPAI and NDV infection in chickens.

    PubMed

    Lee, Dong-Hun; Park, Jae-Keun; Kwon, Jung-Hoon; Yuk, Seong-Su; Erdene-Ochir, Tseren-Ochir; Jang, Yo-Han; Seong, Baik-Lin; Lee, Joong-Bok; Park, Seung-Yong; Choi, In-Soo; Song, Chang-Seon

    2013-01-01

    Highly pathogenic avian influenza (HPAI) and Newcastle disease (ND) are 2 devastating diseases of poultry, which cause great economic losses to the poultry industry. In the present study, we developed a bivalent vaccine containing antigens of inactivated ND and reassortant HPAI H5N1 viruses as a candidate poultry vaccine, and we evaluated its immunogenicity and protective efficacy in specific pathogen-free chickens. The 6:2 reassortant H5N1 vaccine strain containing the surface genes of the A/Chicken/Korea/ES/2003(H5N1) virus was successfully generated by reverse genetics. A polybasic cleavage site of the hemagglutinin segment was replaced by a monobasic cleavage site. We characterized the reverse genetics-derived reassortant HPAI H5N1 clade 2.5 vaccine strain by evaluating its growth kinetics in eggs, minimum effective dose in chickens, and cross-clade immunogenicity against HPAI clade 1 and 2. The bivalent vaccine was prepared by emulsifying inactivated ND (La Sota strain) and reassortant HPAI viruses with Montanide ISA 70 adjuvant. A single immunization with this vaccine induced high levels of hemagglutination-inhibiting antibody titers and protected chickens against a lethal challenge with the wild-type HPAI and ND viruses. Our results demonstrate that the bivalent, inactivated vaccine developed in this study is a promising approach for the control of both HPAI H5N1 and ND viral infections.

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

    PubMed

    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.

  15. 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.

    PubMed

    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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. Assessment of reduced vaccine dose on efficacy of an inactivated avian influenza vaccine against an H5N1 high pathogenicity avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) vaccines have emerged to be a viable emergency tool for use in a comprehensive strategy for dealing with high pathogenicity (HP) AI in developed countries. However, the available doses of inactivated AI vaccine are limited to national vaccine banks and inventory stocks of some ...

  18. Pandemic influenza A (H1N1) virus infection and avian influenza A (H5N1) virus infection: a comparative analysis.

    PubMed

    Korteweg, Christine; Gu, Jiang

    2010-08-01

    The 2009 H1N1 and H5N1 influenza viruses are newly (re-) emerged influenza A viruses (2009 A(H1N1) and A(H5N1), respectively) that have recently posed tremendous health threats in many regions worldwide. With the 2009 outbreak of H1N1 influenza A, the world witnessed the first influenza pandemic of the 21st century. The disease has rapidly spread across the entire globe, and has resulted in hundreds of thousands of cases with confirmed infection. Although characterized by high transmissibility, the virulence and fatality of the 2009 A(H1N1) influenza virus have thus far remained relatively low. The reverse holds true for A(H5N1) influenza; at a fatality rate that exceeds 60%, it is known to cause severe damage to the human respiratory system, but is not presently capable of efficient transmission from human to human. Apart from the clear differences between the two types of influenza, there are some significant similarities that warrant attention. In particular, the more severe and fatal 2009 A(H1N1) influenza cases have shown symptoms similar to those reported in cases of A(H5N1) influenza. Histopathological findings for these cases, to the extent available, also appear to have similarities for both diseases in terms of damage and severity. Here we review important recent publications in this area, and we discuss some of the key commonalities and contrasts between the two influenza A types in terms of their biology, origins, clinical features, pathology and pathogenesis, and receptors and transmissibility.

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

    DTIC Science & Technology

    2012-02-07

    information from official sources (e.g. World Health Organization, Office International des Epizooties and the European Union), unofficial sources (e.g...Muzaffar); India – Ministry of Forestry, Rajasthan Forestry Warden, and Keoladeo National Park (A. Prasad), the BBC (M. Hughes-Games and G. Badger ...Gilbert M, Newman SH, et al. (2010) The cold European winter of 2005–2006 assisted the spread and persistence of H5N1 influenza virus in wild birds

  20. Vaccines with MF59 adjuvant expand the antibody repertoire to target protective sites of pandemic avian H5N1 influenza virus.

    PubMed

    Khurana, Surender; Chearwae, Wanida; Castellino, Flora; Manischewitz, Jody; King, Lisa R; Honorkiewicz, Agnieszka; Rock, Michael T; Edwards, Kathryn M; Del Giudice, Giuseppe; Rappuoli, Rino; Golding, Hana

    2010-01-20

    Vaccines against influenza viruses with pandemic potential, including H5N1, are under development. Because of a lack of preexisting immunity to these viruses, adjuvants (immune potentiators or enhancers) are needed to improve immune responses, to conserve scarce vaccine, and for cross-protection against strains that have drifted evolutionarily from the original. Aluminum-based adjuvants do not improve vaccine immunogenicity for influenza subunit vaccines, whereas oil-in-water adjuvants are effective, especially with H5N1-inactivated vaccines. We used whole-genome-fragment phage display libraries followed by surface plasmon resonance (SPR) technologies to elucidate the effect of different adjuvants on the antibody repertoire against H5N1 vaccine in humans. The oil-in-water adjuvant MF59 induced epitope spreading from HA2 to HA1 in hemagglutinin (HA) and neuraminidase relative to unadjuvanted or aluminum-adjuvanted vaccines. Moreover, we observed an increase by a factor of 20 in the frequency of HA1-to-HA2-specific phage clones in sera after MF59-adjuvanted vaccine administration and a factor of 2 to 3 increase in the avidity of antibodies binding to properly folded HA1(28-319), as measured by SPR. The adjuvant-dependent increase in binding to conformational HA1 epitopes correlated with broadening of cross-clade neutralization and predicted improved in vivo protection. Thus, MF59 adjuvant improves the immune response to a H5N1 vaccine by inducing qualitative and quantitative expansion of the antibody repertoires with protective potential.

  1. Qualitative detection of avian influenza A (H5N1) viruses: a comparative evaluation of four real-time nucleic acid amplification methods.

    PubMed

    Chantratita, Wasun; Sukasem, Chonlaphat; Kaewpongsri, Supaporn; Srichunrusami, Chutatip; Pairoj, Wantanit; Thitithanyanont, Arunee; Chaichoune, Kridsada; Ratanakron, Parntep; Songserm, Thaweesak; Damrongwatanapokin, Sudarat; Landt, Olfert

    2008-01-01

    The aim of this study was to determine the performance of real-time amplification based methods - NASBA, TaqMan, RT-FRET, and RT-PCR LUXtrade mark formats - for the detection of influenza A (H5N1) virus RNA. In an analysis of 54 samples obtained from a range of animal species in Thailand during the period 2003-2006, results showed that the NASBA (H5=98.2%, N1=96.3%), TaqMan (H5=98.2%, N1=96.3%) and FRET (H5=98.2%, N1=96.3%) had significantly higher rates of positive detection than LUX (H5=94.4%, N1=50.0%; P<0.001) for influenza A, H5 and N1 isolates. There were no false-positive results from any methods used in the negative-control group of samples. The limits of analytical detection were at least 10copies/reaction in real-time NASBA and LUX assays, while FRET and TaqMan assay appeared to be less sensitive at > or =100copies/reaction. The assays were relatively specific without cross-reactivity to a number of other influenza strains or viral pathogens. In conclusion, our study demonstrated that real-time NASBA, TaqMan and FRET assays can be used to detect influenza A (H5N1) from a wide range of hosts, and be specific for H5N1 samples obtained during different outbreaks (2003-2006). All assays provided the benefit of rapid influenza H5N1 identification for early diagnosis, in the range of hours, and they are well suited to high throughput analyses.

  2. Highly pathogenic avian influenza (H5N1) in ducks and in-contact chickens in backyard and smallholder commercial duck farms in Viet Nam.

    PubMed

    Henning, Joerg; Henning, Kate A; Morton, John M; Long, Ngo T; Ha, Nguyen T; Vu, Le T; Vu, Pham P; Hoa, Dong M; Meers, Joanne

    2011-09-01

    Scavenging ducks are thought to play an important role in the maintenance and transmission of highly pathogenic avian influenza (HPAI) H5N1 virus among domesticated and wild bird populations in South East Asia, but detailed field epidemiological results describing the infection status of domestic ducks and in-contact chickens have not been published. We conducted a longitudinal study, monitoring ducks and in-contact chickens in 80 flocks in the Mekong Delta of Viet Nam with bi-monthly testing from May 2007 until May 2008. Because H5 vaccination campaigns are conducted at regular intervals in poultry flocks in Viet Nam, both unvaccinated sentinel and H5 vaccinates were monitored. On each farm, a total of 10 birds were selected: 7 ducks (4 unvaccinated and 3 vaccinated) and 3 chickens (2 unvaccinated and 1 vaccinated) that were in close contact with the ducks. Blood samples were tested for H5 antibodies using the hemagglutination inhibition test, with H5 antibody titers ≥2(4) considered to indicate past exposure to H5 field or vaccine virus. Titers of vaccinated birds were analyzed for samples collected more than 3 weeks post-vaccination. Pooled oropharyngeal and cloacal swabs were assessed for H5 viral RNA using real-time PCR. Bird- and flock-level prevalences were estimated accounting for sampling fractions and clustering under the multi-stage sampling design with birds being sampled within flocks within villages in four different provinces. In total, serum and swab samples from 5409 birds-samplings were analyzed. Bird-level seroprevalence was 17.5% (95% CI: 14.1, 20.9) amongst unvaccinated ducks and 10.7% (95% CI: 7.4, 14.4) amongst unvaccinated in-contact chickens. Flock-level seroprevalence (proportion of flock-visits with at least one unvaccinated bird test positive) was 42.6% (95% CI: 38.0, 47.2) for ducks and 19.0% (95% CI: 13.6, 24.4) for chickens. Only 54.3% (95% CI: 39.2, 69.3) of vaccinated ducks and 55.5% (95% CI: 46.8, 64.2) of vaccinated in

  3. Multiple introductions of a reassortant H5N1 avian influenza virus of clade 2.3.2.1c with PB2 gene of H9N2 subtype into Indian poultry.

    PubMed

    Tosh, Chakradhar; Nagarajan, Shanmugasundaram; Kumar, Manoj; Murugkar, Harshad V; Venkatesh, Govindarajulu; Shukla, Shweta; Mishra, Amit; Mishra, Pranav; Agarwal, Sonam; Singh, Bharati; Dubey, Prashant; Tripathi, Sushil; Kulkarni, Diwakar D

    2016-09-01

    Highly pathogenic avian influenza (HPAI) H5N1 viruses are a threat to poultry in Asia, Europe, Africa and North America. Here, we report isolation and characterization of H5N1 viruses isolated from ducks and turkeys in Kerala, Chandigarh and Uttar Pradesh, India between November 2014 and March 2015. Genetic and phylogenetic analyses of haemagglutinin gene identified that the virus belonged to a new clade 2.3.2.1c which has not been detected earlier in Indian poultry. The virus possessed molecular signature for high pathogenicity to chickens, which was corroborated by intravenous pathogenicity index of 2.96. The virus was a reassortant which derives its PB2 gene from H9N2 virus isolated in China during 2007-2013. However, the neuraminidase and internal genes are of H5N1 subtype. Phylogenetic and network analysis revealed that after detection in China in 2013/2014, the virus moved to Europe, West Africa and other Asian countries including India. The analyses further indicated multiple introductions of H5N1 virus in Indian poultry and internal spread in Kerala. One of the outbreaks in ducks in Kerala is linked to the H5N1 virus isolated from wild birds in Dubai suggesting movement of virus probably through migration of wild birds. However, the outbreaks in ducks in Chandigarh and Uttar Pradesh were from an unknown source in Asia which also contributed gene pools to the outbreaks in Europe and West Africa. The widespread incidence of the novel H5N1 HPAI is similar to the spread of clade 2.2 ("Qinghai-like") virus in 2005, and should be monitored to avoid threat to animal and public health.

  4. Replication and pathogenesis associated with H5N1, H5N2, and H5N3 low-pathogenic avian influenza virus infection in chickens and ducks.

    PubMed

    Mundt, Egbert; Gay, Lauren; Jones, Les; Saavedra, Geraldine; Tompkins, S Mark; Tripp, Ralph A

    2009-01-01

    A comparative study examining replication and disease pathogenesis associated with low-pathogenic H5N1, H5N2, or H5N3 avian influenza virus (AIV) infection of chickens and ducks was performed. The replication and pathogenesis of highly pathogenic AIV (HPAIV) has received substantial attention; however, the behavior of low-pathogenic AIVs, which serve as precursors to HPAIVs, has received less attention. Thus, chickens or ducks were inoculated with an isolate from a wild bird [A/Mute Swan/MI/451072/06 (H5N1)] or isolates from chickens [A/Ck/PA/13609/93 (H5N2), A/Ck/TX/167280-4/02 (H5N3)], and virus replication, induction of a serological response, and disease pathogenesis were investigated, and the hemagglutinin and neuraminidase (NA) gene sequences of the isolates were determined. Virus isolated from tracheal and cloacal swabs showed that H5N1 replicated better in ducks, whereas H5N2 and H5N3 replicated better in chickens. Comparison of the NA gene sequences showed that chicken-adapted H5N2 and H5N3 isolates both have a deletion of 20 amino acids in the NA stalk region, which was absent in the H5N1 isolate. Histopathological examination of numerous organs showed that H5N2 and H5N3 isolates caused lesions in chickens in a variety of organs, but to a greater extent in the respiratory and intestinal tracts, whereas H5N1 lesions in ducks were observed mainly in the respiratory tract. This study suggests that the H5N1, H5N2, and H5N3 infections occurred at distinct sites in chicken and ducks, and that comparative studies in different model species are needed to better understand the factors influencing the evolution of these viruses.

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

    PubMed Central

    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 < 0.001) or H5N1 clade 2.3.4 virus (IRR: 10.58; p < 0.001). Although risks of H7N9 and H5N1 virus infections remain low in Beijing, continued preventive measures are warranted for poultry workers. PMID:27670286

  6. Comparative Epidemiology of Human Fatal Infections with Novel, High (H5N6 and H5N1) and Low (H7N9 and H9N2) Pathogenicity Avian Influenza A Viruses

    PubMed Central

    Wu, Zu-Qun; Zhang, Yi; Zhao, Na; Yu, Zhao; Pan, Hao; Chan, Ta-Chien; Zhang, Zhi-Ruo; Liu, She-Lan

    2017-01-01

    This study aimed to assess the mortality risks for human infection with high (HPAI) and low (LPAI) pathogenicity avian influenza viruses. The HPAI case fatality rate (CFR) was far higher than the LPAI CFR [66.0% (293/444) vs. 68.75% (11/16) vs. 40.4% (265/656) vs. 0.0% (0/18) in the cases with H5N1, H5N6, H7N9, and H9N2 viruses, respectively; p < 0.001]. Similarly, the CFR of the index cases was greater than the secondary cases with H5N1 [100% (43/43) vs. 43.3% (42/97), p < 0.001]. Old age [22.5 vs. 17 years for H5N1, p = 0.018; 61 vs. 49 years for H7H9, p < 0.001], concurrent diseases [18.8% (15/80) vs. 8.33% (9/108) for H5N1, p = 0.046; 58.6% (156/266) vs. 34.8% (135/388) for H7H9, p < 0.001], delayed confirmation [13 vs. 6 days for H5N1, p < 0.001; 10 vs. 8 days for H7N9, p = 0.011] in the fatalities and survivors, were risk factors for deaths. With regard to the H5N1 clusters, exposure to poultry [67.4% (29/43) vs. 45.2% (19/42), p = 0.039] was the higher risk for the primary than the secondary deaths. In conclusion, old age, comorbidities, delayed confirmation, along with poultry exposure are the major risks contributing to fatal outcomes in human HPAI and LPAI infections. PMID:28273867

  7. 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.

    PubMed

    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.

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

    PubMed Central

    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

    2016-01-01

    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. PMID:27436362

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

    PubMed

    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.

  10. Effect of statin treatments on highly pathogenic avian influenza H5N1, seasonal and H1N1pdm09 virus infections in BALB/c mice

    PubMed Central

    Kumaki, Yohichi; Morrey, John D; Barnard, Dale L

    2013-01-01

    Statins are used to control elevated cholesterol or hypercholesterolemia, but have previously been reported to have antiviral properties. Aims To show efficacy of statins in various influenza virus mouse models. Materials & methods BALB/c mice were treated intraperitoneally or orally with several types of statins (simvastatin, lovastatin, mevastatin, pitavastatin, atorvastatin or rosuvastatin) at various concentrations before or after infection with either influenza A/Duck/ MN/1525/81 H5N1 virus, influenza A/Vietnam/1203/2004 H5N1 virus, influenza A/ Victoria/3/75 H3N2 virus, influenza A/NWS/33 H1N1 virus or influenza A/CA/04/09 H1N1pdm09 virus. Results The statins administered intraperitoneally or orally at any dose did not significantly enhance the total survivors relative to untreated controls. In addition, infected mice receiving any concentration of statin were not protected against weight loss due to the infection. None of the statins significantly increased the mean day of death relative to mice in the placebo treatment group. Furthermore, the statins had relatively few ameliorative effects on lung pathology or lung weights at day 3 and 6 after virus exposure, although mice treated with simvastatin did have improved lung function as measured by arterial saturated oxygen levels in one experiment. Conclusion Statins showed relatively little efficacy in any mouse model used by any parameter tested. PMID:23420457

  11. A real-time TaqMan RT-PCR method for neuraminidase type 1 (N1) gene detection of H5N1 Eurasian strains of avian influenza virus.

    PubMed

    Agüero, Montserrat; Sánchez, Azucena; San Miguel, Elena; Gómez-Tejedor, Concepción; Jiménez-Clavero, Miguel Angel

    2007-03-01

    This work describes the development of a real-time RT-PCR (RRT-PCR) procedure for detection of the N1 gene from avian influenza virus (AIV), based on the use of specific primers and a TaqMan-MGB (minor groove binder) probe. Nucleotide sequences of the neuraminidase type 1 gene from a collection of H5N1 Eurasian strains of AIV were aligned using ClustalW software. Conserved regions were located and used to design specific primers and a TaqMan-MGB probe using Primer Express software. A one-step RRT-PCR method was optimized using RNA from the Turkey 2005 H5N1 strain of AIV and can be completed in about 2 hr once the RNA is extracted from the sample. The specificity of the assay was assessed with non-N1 AIV strains, another related avian virus, and different avian tissue samples from healthy animals. Sensitivity was determined using 10-fold serial dilutions of the H5N1 Turkey 2005 strain and was compared with the generic RRT-PCR detection method, targeted at the matrix protein gene of AIV, commonly used at the Spanish AIV National Reference Laboratory. The N1 detection method proved to be even more sensitive than the generic (matrix-based) method, allowing a very quick confirmation (or discarding) of any Eurasian N1 strain when a positive result was obtained with the matrix RRT-PCR assay. Combined with RRT-PCR tests for general detection of AIV and H5 typing in use at the NRL, the procedure here described allows characterizing of any H5N1 Eurasian AIV strain in a field sample within a working day.

  12. Differential immune response of mallard duck peripheral blood mononuclear cells to two highly pathogenic avian influenza H5N1 viruses with distinct pathogenicity in mallard ducks.

    PubMed

    Cui, Zhu; Hu, Jiao; He, Liang; Li, Qunhui; Gu, Min; Wang, Xiaoquan; Hu, Shunlin; Liu, Huimou; Liu, Wenbo; Liu, Xiaowen; Liu, Xiufan

    2014-02-01

    CK10 and GS10 are two H5N1 highly pathogenic influenza viruses of similar genetic background but differ in their pathogenicity in mallard ducks. CK10 is highly pathogenic whereas GS10 is low pathogenic. In this study, strong inflammatory response in terms of the expression level of several cytokines was observed in mallard duck peripheral blood mononuclear cells (PBMC) infected with CK10 while mild response was triggered in those by GS10 infection. Two remarkable and intense peaks of immune response were induced by CK10 infection within 24 hours (at 8 and 24 hours post infection, respectively) without reducing the virus replication. Our observations indicated that sustained and intense innate immune responses may be central to the high pathogenicity caused by CK10 in ducks.

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

    PubMed

    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.

  14. 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.

    PubMed

    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.

  15. Multiple introduction of Asian H5N1 avian influenza virus in Croatia by wild birds during 2005-2006 and isolation of the virus from apparently healthy black-headed gulls (Larus ridibundus).

    PubMed

    Savić, Vladimir; Labrović, Ankica; Zelenika, Tajana Amsel; Balenović, Mirta; Separović, Sanja; Jurinović, Luka

    2010-11-01

    This study describes the introduction and spread of avian influenza A (H5N1) subtype in Croatia. Seventeen isolates were identified during the period from October 2005 to March 2006, all originating from wild birds. The full-length nucleotide sequence analysis of the hemagglutinin (HA) gene of seven representative isolates revealed that three distinct genetic strains involved in the outbreaks, implicating at least three independent introductions of the virus into Croatia during a relatively short period of time. All three genetic strains belonged to clade 2.2 (Qinghai-like viruses) and each strain displayed significant similarity to concurrent H5N1 viruses from other European countries. The dominant strain of the virus was present in all four affected areas and in all three bird species (mute swan, mallard, and black-headed gull), indicating cross-species transmission of the virus. Two other genetic strains were found, together with the dominant strain, only in a marsh at the Adriatic coast during late February and early March 2006, which could be associated with frozen water surfaces in the continental part of Croatia as well as in Eastern Europe in early 2006 and the movement of birds toward warmer areas. This is also the first isolation of highly pathogenic avian influenza virus of H5N1 subtype from apparently healthy black-headed gulls.

  16. A comparative evaluation of feathers, oropharyngeal swabs, and cloacal swabs for the detection of H5N1 highly pathogenic avian influenza virus infection in experimentally infected chickens and ducks.

    PubMed

    Nuradji, Harimurti; Bingham, John; Lowther, Sue; Wibawa, Hendra; Colling, Axel; Long, Ngo Thanh; Meers, Joanne

    2015-11-01

    Oropharyngeal and cloacal swabs have been widely used for the detection of H5N1 highly pathogenic avian Influenza A virus (HPAI virus) in birds. Previous studies have shown that the feather calamus is a site of H5N1 virus replication and therefore has potential for diagnosis of avian influenza. However, studies characterizing the value of feathers for this purpose are not available, to our knowledge; herein we present a study investigating feathers for detection of H5N1 virus. Ducks and chickens were experimentally infected with H5N1 HPAI virus belonging to 1 of 3 clades (Indonesian clades 2.1.1 and 2.1.3, Vietnamese clade 1). Different types of feathers and oropharyngeal and cloacal swab samples were compared by virus isolation. In chickens, virus was detected from all sample types: oral and cloacal swabs, and immature pectorosternal, flight, and tail feathers. During clinical disease, the viral titers were higher in feathers than swabs. In ducks, the proportion of virus-positive samples was variable depending on viral strain and time from challenge; cloacal swabs and mature pectorosternal feathers were clearly inferior to oral swabs and immature pectorosternal, tail, and flight feathers. In ducks infected with Indonesian strains, in which most birds did not develop clinical signs, all sampling methods gave intermittent positive results; 3-23% of immature pectorosternal feathers were positive during the acute infection period; oropharyngeal swabs had slightly higher positivity during early infection, while feathers performed better during late infection. Our results indicate that immature feathers are an alternative sample for the diagnosis of HPAI in chickens and ducks.

  17. [Study on the histopathology of cats inoculated with H5N1 subtype high pathogenic avian influenza virus originated from tigers].

    PubMed

    Chang, Shuang; Ding, Zhuang; Yang, Song-Tao; Gao, Yu-Wei; Zou, Xiao-Huan; Wang, Tie-Cheng; Xia, Xian-Zhu

    2007-11-01

    In this study, the HPAIV A/Tiger/Harbin/01/2002 (H5N1) used was originated from tigers and propagated in SPF embryonated hen eggs. TCID5, of the virus was 10(-7.36)/0. 05mL on MDCK cell. The cats were inoculated through bronchus route and then, the cats of dead and control were collected for histopathological and immunohistochemistry examination. Meanwhile, the emulsion supernatant fluid of organs and the pharyngeal swab samples of the dead cats were collected for RT-PCR, survived cats and the control cats were tested for the presence of HI antibody by standard method. The results indicated that the damage of lungs from the dead cats were most obvious, the wide range of red consolidation focus emerged on the lobus pulmonis, the fused focus of infection caused injury of lungs. Histology under the microscope revealed diffuse alveolar damage, confluence phlegmasia pathology, infiltration of lymphomonocytes, sackful of infiltration of macrophages and manipulus protein-like effusion in the alveolar. By immunohistochemistry, the positively stained virus particles were found on the epithelial cells of bronchus and alveolus, and also in the endochylema of lymphomonocytes. The specific electophoretic band of 464bp amplified by RT-PCR from samples of pharyngeal swabs, lungs, kidneys, hearts and brains was as same as the theory value. HI antibody titers of the survived cat were 1:32.

  18. H5N1 vaccines in humans

    PubMed Central

    Baz, Mariana; Luke, Catherine J; Cheng, Xing; Jin, Hong; Subbarao, Kanta

    2013-01-01

    The spread of highly pathogenic avian H5N1 influenza viruses since 1997 and their virulence for poultry and humans has raised concerns about their potential to cause an influenza pandemic. Vaccines offer the most viable means to combat a pandemic threat. However, it will be a challenge to produce, distribute and implement a new vaccine if a pandemic spreads rapidly. Therefore, efforts are being undertaken to develop pandemic vaccines that use less antigen and induce cross-protective and long-lasting responses, that can be administered as soon as a pandemic is declared or possibly even before, in order to prime the population and allow for a rapid and protective antibody response. In the last few years, several vaccine manufacturers have developed candidate pandemic and pre-pandemic vaccines, based on reverse genetics and have improved the immunogenicity by formulating these vaccines with different adjuvants. Some of the important and consistent observations from clinical studies with H5N1 vaccines are as follows: two doses of inactivated vaccine are generally necessary to elicit the level of immunity required to meet licensure criteria, less antigen can be used if an oil-in-water adjuvant is included, in general antibody titers decline rapidly but can be boosted with additional doses of vaccine and if high titers of antibody are elicited, cross-reactivity against other clades is observed. Prime-boost strategies elicit a more robust immune response. In this review, we discuss data from clinical trials with a variety of H5N1 influenza vaccines. We also describe studies conducted in animal models to explore the possibility of reassortment between pandemic live attenuated vaccine candidates and seasonal influenza viruses, since this is an important consideration for the use of live vaccines in a pandemic setting. PMID:23726847

  19. 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.

    PubMed

    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.

  20. 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.

    PubMed

    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.

  1. 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

    PubMed Central

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

    2012-01-01

    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. PMID:22496212

  2. The T160A hemagglutinin substitution affects not only receptor binding property but also transmissibility of H5N1 clade 2.3.4 avian influenza virus in guinea pigs.

    PubMed

    Gu, Min; Li, Qunhui; Gao, Ruyi; He, Dongchang; Xu, Yunpeng; Xu, Haixu; Xu, Lijun; Wang, Xiaoquan; Hu, Jiao; Liu, Xiaowen; Hu, Shunlin; Peng, Daxin; Jiao, Xinan; Liu, Xiufan

    2017-02-06

    We generated and characterized site-directed HA mutants on the genetic backbone of H5N1 clade 2.3.4 virus preferentially binding to α-2,3 receptors in order to identify the key determinants in hemagglutinin rendering the dual affinity to both α-2,3 (avian-type) and α-2,6 (human-type) linked sialic acid receptors of the current clade 2.3.4.4 H5NX subtype avian influenza reassortants. The results show that the T160A substitution resulted in the loss of a glycosylation site at 158N and led not only to enhanced binding specificity for human-type receptors but also transmissibility among guinea pigs, which could be considered as an important molecular marker for assessing pandemic potential of H5 subtype avian influenza isolates.

  3. Sensitization with vaccinia virus encoding H5N1 hemagglutinin restores immune potential against H5N1 influenza virus

    PubMed Central

    Yasui, Fumihiko; Itoh, Yasushi; Ikejiri, Ai; Kitabatake, Masahiro; Sakaguchi, Nobuo; Munekata, Keisuke; Shichinohe, Shintaro; Hayashi, Yukiko; Ishigaki, Hirohito; Nakayama, Misako; Sakoda, Yoshihiro; Kida, Hiroshi; Ogasawara, Kazumasa; Kohara, Michinori

    2016-01-01

    H5N1 highly pathogenic avian influenza (H5N1 HPAI) virus causes elevated mortality compared with seasonal influenza viruses like H1N1 pandemic influenza (H1N1 pdm) virus. We identified a mechanism associated with the severe symptoms seen with H5N1 HPAI virus infection. H5N1 HPAI virus infection induced a decrease of dendritic cell number in the splenic extrafollicular T-cell zone and impaired formation of the outer layers of B-cell follicles, resulting in insufficient levels of antibody production after infection. However, in animals vaccinated with a live recombinant vaccinia virus expressing the H5 hemagglutinin, infection with H5N1 HPAI virus induced parafollicular dendritic cell accumulation and efficient antibody production. These results indicate that a recombinant vaccinia encoding H5 hemagglutinin gene does not impair dendritic cell recruitment and can be a useful vaccine candidate. PMID:27892498

  4. Protective efficacy of a recombinant HVT-H5 vaccine against lethal H5N1 and H5N2 avian influenza challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccination is an important tool in the protection of poultry against avian influenza (AI). For field use, the overwhelming majority of AI vaccines produced are inactivated whole virus formulated into an oil emulsion. However, recombinant vectored vaccines (e.g. expressing AI genes) are gaining us...

  5. NP, PB1 and PB2 viral genes contribute to altered replication of H5N1 avian influenza viruses in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The virulence determinant for highly pathogenic avian influenza viruses is considered multigenic, although the best characterized virulence factor is the hemagglutinin cleavage site. The capability of influenza viruses to reassort gene segments is one potential way for new viruses to emerge with di...

  6. Replication of H5N1 avian influenza viruses in chickens is affected by the PB1, PB2 and NP viral genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Devastating losses to the poultry industry can result from pathogenic avian influenza viruses (AIVs) created by natural reassortment events. The role of individual viral genes on the pathogenesis of AIVs in chickens is unclear. Reverse genetics was used to create single-gene reassortants to determ...

  7. A single substitution in amino acid 184 of the NP protein alters the replication and pathogenicity of H5N1 avian influenza viruses in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously we found that exchanging the NP genes of recombinant avian influenza viruses (AIVs) affected viral replication and altered host gene expression and mean death times in chickens infected with these viruses. Five amino acids at positions 22, 184, 400, 406, and 423 were different between th...

  8. Comparison of potency required for protection against H7N3 or H5N1 highly pathogenic avian influenza following vaccination and challenge with homologous virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Outbreaks of H5 and H7 highly pathogenic avian influenza (HPAI) in commercial poultry are a constant threat to food supplies and animal/human health. While vaccination can enhance protection and reduce the spread of disease, there is considerable evidence that the level of immunity required for pro...

  9. Vaccination of SPF turkeys with a recombinant HVT expressing the HA from H5N1 highly pathogenic avian influenza protects against lethal challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccination is an important tool in the protection of poultry against avian influenza (AI). For field use, the overwhelming majority of AI vaccines produced are inactivated whole virus formulated into an oil emulsion and to a lesser degree recombinant vectored vaccines (e.g. virus expressing AI gen...

  10. Vaccination of SPF chickens with recombinant HVT expressing the HA from H5N1 highly pathogenic avian influenza protects against lethal challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccination is an important tool in the protection of poultry against avian influenza (AI). For field use, the overwhelming majority of AI vaccines produced are inactivated whole virus formulated into an oil emulsion and to a lesser degree recombinant vectored vaccines (e.g. virus expressing AI gen...

  11. Protective efficacy of a recombinant HVT-H5 vaccine against lethal H5N1 and H5N2 avian influenza challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protective immunity against highly pathogenic avian influenza (HPAI) largely depends on the development of an antibody response against a subtype-specific lineage of challenge virus. In the poultry industry, inactivated AI vaccines are typically produced with indigenous AI isolates to provide the b...

  12. Impact of vaccination on infection with Vietnam H5N1 high pathogenicity avian influenza virus in hens and the eggs they lay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic avian influenza virus (HPAIV) infections in chickens produce a negative impact on egg production, and virus is deposited on surface and internal contents of eggs. Previously, vaccination maintained egg production and reduced egg contamination when challenged with a North American H...

  13. Modeling the association of space, time, and host species with variation of the HA, NA, and NS genes of H5N1 highly pathogenic avian influenza viruses isolated from birds in Romania in 2005-2007.

    PubMed

    Alkhamis, Mohammad; Perez, Andres; Batey, Nicole; Howard, Wendy; Baillie, Greg; Watson, Simon; Franz, Stephanie; Focosi-Snyman, Raffaella; Onita, Iuliana; Cioranu, Raluca; Turcitu, Mihai; Kellam, Paul; Brown, Ian H; Breed, Andrew C

    2013-09-01

    Molecular characterization studies of a diverse collection of avian influenza viruses (AIVs) have demonstrated that AIVs' greatest genetic variability lies in the HA, NA, and NS genes. The objective here was to quantify the association between geographical locations, periods of time, and host species and pairwise nucleotide variation in the HA, NA, and NS genes of 70 isolates of H5N1 highly pathogenic avian influenza virus (HPAIV) collected from October 2005 to December 2007 from birds in Romania. A mixed-binomial Bayesian regression model was used to quantify the probability of nucleotide variation between isolates and its association with space, time, and host species. As expected for the three target genes, a higher probability of nucleotide differences (odds ratios [ORs] > 1) was found between viruses sampled from places at greater geographical distances from each other, viruses sampled over greater periods of time, and viruses derived from different species. The modeling approach in the present study maybe useful in further understanding the molecular epidemiology of H5N1 HPAI virus in bird populations. The methodology presented here will be useful in predicting the most likely genetic distance for any of the three gene segments of viruses that have not yet been isolated or sequenced based on space, time, and host species during the course of an epidemic.

  14. Low-pathogenic avian influenza virus A/turkey/Ontario/6213/1966 (H5N1) is the progenitor of highly pathogenic A/turkey/Ontario/7732/1966 (H5N9)

    PubMed Central

    Ping, Jihui; Selman, Mohammed; Tyler, Shaun; Forbes, Nicole; Keleta, Liya

    2012-01-01

    The first confirmed outbreak of highly pathogenic avian influenza (HPAI) virus infections in North America was caused by A/turkey/Ontario/7732/1966 (H5N9); however, the phylogeny of this virus is largely unknown. This study performed genomic sequence analysis of 11 avian influenza isolates from 1956 to 1979 for comparison with A/turkey/Ontario/7732/1966 (H5N9). Phylogenetic and genetic analyses included these viruses in combination with all known full-genome sequences of avian viruses isolated before 1981. It was shown that a low-pathogenic avian influenza virus, A/turkey/Ontario/6213/1966 (H5N1), that had been isolated 3 months previously, was the closest known genetic relative with six genome segments of common lineage encoding the polymerase subunits PB2, PB1 and PA, nucleoprotein (NP), haemagglutinin (HA) and non-structural (NS) proteins. The lineages of these genome segments included reassortment with other North American turkey viruses that were all rooted in North American wild waterfowl with the HA gene originating from the H5N2 serotype. The phylogenies demonstrated adaptation from North American wild birds to turkeys with the possible involvement of domestic waterfowl. The turkey isolate, A/turkey/Wisconsin/1968 (H5N9), was the second most closely related poultry isolate to A/turkey/Ontario/7732/1966 (H5N9), possessing five common lineage genome segments (PB2, PB1, PA, HA and neuraminidase). The A/turkey/Ontario/6213/1966 (H5N1) virus was more virulent than A/turkey/Wisconsin/68 (H5N9) for chicken embryos and mice, indicating a greater biological similarity to A/turkey/Ontario/7732/1966 (H5N9). Thus, A/turkey/Ontario/6213/1966 (H5N1) was identified as the closest known ancestral relative of HPAI A/turkey/Ontario/7732/1966 (H5N9), which will serve as a useful reference virus for characterizing the early genetic and biological properties associated with the emergence of pathogenic avian influenza strains. PMID:22592261

  15. Comprehensive Serological Analysis of Two Successive Heterologous Vaccines against H5N1 Avian Influenza Virus in Exotic Birds in Zoos▿

    PubMed Central

    Vergara-Alert, Júlia; Fernández-Bellon, Hugo; Busquets, Núria; Alcántara, Gabriel; Delclaux, María; Pizarro, Bienvenido; Sánchez, Celia; Sánchez, Azucena; Majó, Natàlia; Darji, Ayub

    2011-01-01

    In 2005, European Commission directive 2005/744/EC allowed controlled vaccination against avian influenza (AI) virus of valuable avian species housed in zoos. In 2006, 15 Spanish zoos and wildlife centers began a vaccination program with a commercial inactivated H5N9 vaccine. Between November 2007 and May 2008, birds from 10 of these centers were vaccinated again with a commercial inactivated H5N3 vaccine. During these campaigns, pre- and postvaccination samples from different bird orders were taken to study the response against AI virus H5 vaccines. Sera prior to vaccinations with both vaccines were examined for the presence of total antibodies against influenza A nucleoprotein (NP) by a commercial competitive enzyme-linked immunosorbent assay (cELISA). Humoral responses to vaccination were evaluated using a hemagglutination inhibition (HI) assay. In some taxonomic orders, both vaccines elicited comparatively high titers of HI antibodies against H5. Interestingly, some orders, such as Psittaciformes, which did not develop HI antibodies to either vaccine formulation when used alone, triggered notable HI antibody production, albeit in low HI titers, when primed with H5N9 and during subsequent boosting with the H5N3 vaccine. Vaccination with successive heterologous vaccines may represent the best alternative to widely protect valuable and/or endangered bird species against highly pathogenic AI virus infection. PMID:21430124

  16. 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).

    PubMed

    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 < 0.05). Neither rHVT-H5/2.2 nor standard HVT 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

  17. Experimental and Field Results Regarding Immunity Induced by a Recombinant Turkey Herpesvirus H5 Vector Vaccine Against H5N1 and Other H5 Highly Pathogenic Avian Influenza Virus Challenges.

    PubMed

    Gardin, Yannick; Palya, Vilmos; Dorsey, Kristi Moore; El-Attrache, John; Bonfante, Francesco; Wit, Sjaak de; Kapczynski, Darrell; Kilany, Walid Hamdy; Rauw, Fabienne; Steensels, Mieke; Soejoedono, Retno D

    2016-05-01

    Vaccination against H5N1 highly pathogenic avian influenza (AI) virus (HPAIV) is one of the possible complementary means available for affected countries to control AI when the disease has become, or with a high risk of becoming, endemic. Efficacy of the vaccination against AI relies essentially, but not exclusively, on the capacity of the vaccine to induce immunity against the targeted virus (which is prone to undergo antigenic variations), as well as its capacity to overcome interference with maternal immunity transmitted by immunized breeding hens to their progeny. This property of the vaccine is a prerequisite for its administration at the hatchery, which assures higher and more reliable vaccine coverage of the populations than vaccination at the farm. A recombinant vector vaccine (Vectormune® AI), based on turkey herpesvirus expressing the hemagglutinin gene of an H5N1 HPAIV as an insert, has been used in several experiments conducted in different research laboratories, as well as in controlled field trials. The results have demonstrated a high degree of homologous and cross protection against different genetic clades of the H5N1 HPAIV. Furthermore, vaccine-induced immunity was not impaired by the presence of passive immunity, but on the contrary, cumulated with it for improved early protection. The demonstrated levels of protection against the different challenge viruses exhibited variations in terms of postchallenge mortality, as well as challenge virus shedding. The data presented here highlight the advantages of this vaccine as a useful and reliable tool to complement biosecurity and sanitary policies for better controlling the disease due to HPAIV of H5 subtypes, when the vaccination is applied as a control measure.

  18. Tissue tropism of highly pathogenic avian influenza virus subtype H5N1 in naturally infected mute swans (Cygnus Olor ), domestic geese (Aser Anser var. domestica), pekin ducks (Anas platyrhynchos) and mulard ducks ( Cairina moschata x anas platyrhynchos).

    PubMed

    Szeredi, Levente; Dán, Adám; Pálmai, Nimród; Ursu, Krisztina; Bálint, Adám; Szeleczky, Zsófia; Ivanics, Eva; Erdélyi, Károly; Rigó, Dóra; Tekes, Lajos; Glávits, Róbert

    2010-03-01

    The 2006 epidemic due to highly pathogenic avian influenza virus (HPAIV) subtype H5N1 in Hungary caused the most severe losses in waterfowl which were, according to the literature at the time, supposed to be the most resistant to this pathogen. The presence of pathological lesions and the amount of viral antigen were quantified by gross pathology, histopathology and immunohistochemistry (IHC) in the organs of four waterfowl species [mute swans (n = 10), domestic geese (n = 6), mulard ducks (n = 6) and Pekin ducks (n = 5)] collected during the epidemic. H5N1 subtype HPAIV was isolated from all birds examined. Quantitative real-time reverse transcriptase-polymerase chain reaction (qRRT-PCR) was also applied on a subset of samples [domestic geese (n = 3), mulard (n = 4) and Pekin duck (n = 4)] in order to compare its sensitivity with IHC. Viral antigen was detected by IHC in all cases. However, the overall presence of viral antigen in tissue samples was quite variable: virus antigen was present in 56/81 (69%) swan, 22/38 (58%) goose, 28/46 (61%) mulard duck and 5/43 (12%) Pekin duck tissue samples. HPAIV subtype H5N1 was detected by qRRT-PCR in all birds examined, in 19/19 (100%) goose, 7/28 (25%) mulard duck and 12/28 (43%) Pekin duck tissue samples. As compared to qRRTPCR, the IHC was less sensitive in geese and Pekin ducks but more sensitive in mulard ducks. The IHC was consistently positive above 4.31 log10 copies/reaction but it gave very variable results below that level. Neurotropism of the isolated virus strains was demonstrated by finding the largest amount of viral antigen and the highest average RNA load in the brain in all four waterfowl species examined.

  19. 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.

    PubMed

    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 speci