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Sample records for human avian influenza

  1. Avian Influenza A Virus Infections in Humans

    MedlinePlus

    ... Research Making a Candidate Vaccine Virus Related Links Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... Submit What's this? Submit Button Past Newsletters Avian Influenza A Virus Infections in Humans Language: English Españ ...

  2. Avian Influenza

    MedlinePlus

    ... infectious viral disease of birds. Most avian influenza viruses do not infect humans; however some, such as ... often causing no apparent signs of illness. AI viruses can sometimes spread to domestic poultry and cause ...

  3. Avian Influenza (Bird Flu)

    MedlinePlus

    ... this page: About CDC.gov . Avian Influenza H5 Viruses in the United States Updates and Publications Information ... Humans Examples of Human Infections with Avian Influenza Viruses Outbreaks Health Care and Laboratorian Guidance HPAI A ...

  4. Avian Influenza.

    PubMed

    Zeitlin, Gary Adam; Maslow, Melanie Jane

    2005-05-01

    The current epidemic of H5N1 highly pathogenic avian influenza in Southeast Asia raises serious concerns that genetic reassortment will result in the next influenza pandemic. There have been 164 confirmed cases of human infection with avian influenza since 1996. In 2004, there were 45 cases of human H5N1 in Vietnam and Thailand, with a mortality rate more than 70%. In addition to the potential public health hazard, the current zoonotic epidemic has caused severe economic losses. Efforts must be concentrated on early detection of bird outbreaks with aggressive culling, quarantining, and disinfection. To prepare for and prevent an increase in human cases, it is essential to improve detection methods and stockpile effective antivirals. Novel therapeutic modalities, including short-interfering RNAs and new vaccine strategies that use plasmid-based genetic systems, offer promise should a pandemic occur. PMID:15847721

  5. Avian influenza.

    PubMed

    Zeitlin, Gary A; Maslow, Melanie J

    2006-03-01

    The current epidemic of H5N1 highly pathogenic avian influenza in Southeast Asia raises serious concerns that genetic reassortment will result in the next influenza pandemic. There have been 164 confirmed cases of human infection with avian influenza since 1996. In 2004 alone, there were 45 cases of human H5N1 in Vietnam and Thailand, with a mortality rate over 70%. In addition to the potential public health hazard, the current zoonotic epidemic has caused severe economic losses. Efforts must be concentrated on early detection of bird outbreaks with aggressive culling, quarantines, and disinfection. To prepare for and prevent increased human cases, it is essential to improve detection methods and stockpile effective antivirals. Novel therapeutic modalities, including short, interfering RNAs and new vaccine strategies that use plasmid-based genetic systems offer promise, should a pandemic occur. PMID:16566867

  6. Decay of Influenza a Viruses of Human and Avian Origin

    PubMed Central

    Mitchell, Chas. A.; Guerin, L. F.; Robillard, John

    1968-01-01

    The decay rate of six strains of Influenza virus Type A of human origin and eight strains of avian origin were examined in aerosol form under fixed conditions of temperature and humidity. Strains of avian origin were demonstrated to have greater resistance to decay of viability. PMID:4234786

  7. Clinical review: Update of avian influenza A infections in humans

    PubMed Central

    Sandrock, Christian; Kelly, Terra

    2007-01-01

    Influenza A viruses have a wide host range for infection, from wild waterfowl to poultry to humans. Recently, the cross-species transmission of avian influenza A, particularly subtype H5N1, has highlighted the importance of the non-human subtypes and their incidence in the human population has increased over the past decade. During cross-species transmission, human disease can range from the asymptomatic to mild conjunctivitis to fulminant pneumonia and death. With these cases, however, the risk for genetic change and development of a novel virus increases, heightening the need for public health and hospital measures. This review discusses the epidemiology, host range, human disease, outcome, treatment, and prevention of cross-transmission of avian influenza A into humans. PMID:17419881

  8. Avian biology, the human influence on global avian influenza transmission, and performing surveillance in wild birds.

    PubMed

    Gibbs, Samantha E J

    2010-06-01

    This paper takes a closer look at three interrelated areas of study: avian host biology, the role of human activities in virus transmission, and the surveillance activities centered on avian influenza in wild birds. There are few ecosystems in which birds are not found. Correspondingly, avian influenza viruses are equally global in distribution, relying on competent avian hosts. The immune systems, annual cycles, feeding behaviors, and migration patterns of these hosts influence the ecology of the disease. Decreased biodiversity has also been linked to heightened disease transmission in several disease systems, and it is evident that active destruction and modification of wetland environments for human use is impacting avian populations drastically. Legal and illegal trade in wild birds present a significant risk for introduction and maintenance of exotic diseases. After the emergence of HPAI H5N1 in Hong Kong in 1996 and the ensuing geographic spread of outbreaks after 2003, both infected countries and those at risk of introduction began intensifying avian influenza surveillance efforts. Several techniques for sampling wild birds for influenza viruses have been applied. Benefits, problems, and biases exist for each method. The wild bird avian influenza surveillance programs taking place across the continents are now scaling back due to the rise of other spending priorities; hopefully the lessons learned from this work will be preserved and will inform future research and disease outbreak response priorities.

  9. Sialic acid content in human saliva and anti-influenza activity against human and avian influenza viruses.

    PubMed

    Limsuwat, Nattavatchara; Suptawiwat, Ornpreya; Boonarkart, Chompunuch; Puthavathana, Pilaipan; Wiriyarat, Witthawat; Auewarakul, Prasert

    2016-03-01

    It was shown previously that human saliva has higher antiviral activity against human influenza viruses than against H5N1 highly pathogenic avian influenza viruses, and that the major anti-influenza activity was associated with sialic-acid-containing molecules. To further characterize the differential susceptibility to saliva among influenza viruses, seasonal influenza A and B virus, pandemic H1N1 virus, and 15 subtypes of avian influenza virus were tested for their susceptibility to human and chicken saliva. Human saliva showed higher hemagglutination inhibition (HI) and neutralization (NT) titers against seasonal influenza A virus and the pandemic H1N1 viruses than against influenza B virus and most avian influenza viruses, except for H9N2 and H12N9 avian influenza viruses, which showed high HI and NT titers. To understand the nature of sialic-acid-containing anti-influenza factors in human saliva, α2,3- and α2,6-linked sialic acid was measured in human saliva samples using a lectin binding and dot blot assay. α2,6-linked sialic acid was found to be more abundant than α2,3-linked sialic acid, and a seasonal H1N1 influenza virus bound more efficiently to human saliva than an H5N1 virus in a dot blot analysis. These data indicated that human saliva contains the sialic acid type corresponding to the binding preference of seasonal influenza viruses.

  10. Sialic acid content in human saliva and anti-influenza activity against human and avian influenza viruses.

    PubMed

    Limsuwat, Nattavatchara; Suptawiwat, Ornpreya; Boonarkart, Chompunuch; Puthavathana, Pilaipan; Wiriyarat, Witthawat; Auewarakul, Prasert

    2016-03-01

    It was shown previously that human saliva has higher antiviral activity against human influenza viruses than against H5N1 highly pathogenic avian influenza viruses, and that the major anti-influenza activity was associated with sialic-acid-containing molecules. To further characterize the differential susceptibility to saliva among influenza viruses, seasonal influenza A and B virus, pandemic H1N1 virus, and 15 subtypes of avian influenza virus were tested for their susceptibility to human and chicken saliva. Human saliva showed higher hemagglutination inhibition (HI) and neutralization (NT) titers against seasonal influenza A virus and the pandemic H1N1 viruses than against influenza B virus and most avian influenza viruses, except for H9N2 and H12N9 avian influenza viruses, which showed high HI and NT titers. To understand the nature of sialic-acid-containing anti-influenza factors in human saliva, α2,3- and α2,6-linked sialic acid was measured in human saliva samples using a lectin binding and dot blot assay. α2,6-linked sialic acid was found to be more abundant than α2,3-linked sialic acid, and a seasonal H1N1 influenza virus bound more efficiently to human saliva than an H5N1 virus in a dot blot analysis. These data indicated that human saliva contains the sialic acid type corresponding to the binding preference of seasonal influenza viruses. PMID:26671828

  11. Human influenza is more effective than avian influenza at antiviral suppression in airway cells.

    PubMed

    Hsu, Alan Chen-Yu; Barr, Ian; Hansbro, Philip M; Wark, Peter A

    2011-06-01

    Airway epithelial cells are the initial site of infection with influenza viruses. The innate immune responses of airway epithelial cells to infection are important in limiting virus replication and spread. However, relatively little is known about the importance of this innate antiviral response to infection. Avian influenza viruses are a potential source of future pandemics; therefore, it is critical to examine the effectiveness of the host antiviral system to different influenza viruses. We used a human influenza (H3N2) and a low-pathogenic avian influenza (H11N9) to assess and compare the antiviral responses of Calu-3 cells. After infection, H3N2 replicated more effectively than the H11N9 in Calu-3 cells. This was not due to differential expression of sialic acid residues on Calu-3 cells, but was attributed to the interference of host antiviral responses by H3N2. H3N2 induced a delayed antiviral signaling and impaired type I and type III IFN induction compared with the H11N9. The gene encoding for nonstructural (NS) 1 protein was transfected into the bronchial epithelial cells (BECs), and the H3N2 NS1 induced a greater inhibition of antiviral responses compared with the H11N9 NS1. Although the low-pathogenic avian influenza virus was capable of infecting BECs, the human influenza virus replicated more effectively than avian influenza virus in BECs, and this was due to a differential ability of the two NS1 proteins to inhibit antiviral responses. This suggests that the subversion of human antiviral responses may be an important requirement for influenza viruses to adapt to the human host and cause disease.

  12. Avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) is type A influenza, which is adapted to an avian host. Although avian influenza has been isolated from numerous avian species, the primary natural hosts for the virus are dabbling ducks, shorebirds, and gulls. The virus can be found world-wide in these species and in o...

  13. Avian influenza virus infection risk in humans with chronic diseases.

    PubMed

    Zhong, Yaogang; Qin, Yannan; Yu, Hanjie; Yu, Jingmin; Wu, Haoxiang; Chen, Lin; Zhang, Peixin; Wang, Xiurong; Jia, Zhansheng; Guo, Yonghong; Zhang, Hua; Shan, Junjie; Wang, Yuxia; Xie, Hailong; Li, Xiaojie; Li, Zheng

    2015-01-01

    Saliva proteins may protect older people from influenza, however, it is often noted that hospitalizations and deaths after an influenza infection mainly occur in the elderly population living with chronic diseases, such as diabetes and cancer. Our objective was to investigate the expression level of the terminal α2-3- and α2-6-linked sialic acids in human saliva from type 2 diabetes mellitus (T2DM), liver disease and gastric cancer (GC) patients and assess the binding activity of these linked sialic acids against influenza A viruses (IAV). We observed that the expression level of the terminal α2-3-linked sialic acids of elderly individuals with T2DM and liver disease were down-regulated significantly, and the terminal α2-6 linked sialic acids were up-regulated slightly or had no significant alteration. However, in the saliva of patients with GC, neither sialic acid was significantly altered. These findings may reveal that elderly individuals with chronic diseases, such as diabetes and liver disease, might be more susceptible to the avian influenza virus due to the decreased expression of terminal α2-3-linked sialic acids in their saliva.

  14. BirdFlu2009: Avian Influenza and Human Health. 9-10 September 2009, Oxford, UK.

    PubMed

    Temperton, Nigel

    2009-11-01

    The BirdFlu2009 meeting entitled Avian Influenza and Human Health, held in Oxford, included topics covering new developments in the control of seasonal, avian and swine influenza virus infection, with a focus on the human-animal interface. This conference report highlights selected presentations on sialidase therapy for influenza infection, the use of IVIgs to study antibody diversity and reactivity, detecting oseltamivir carboxylate in waste water, H5N1 infection in Egyptian children, preparedness for an influenza pandemic and an indirect sandwich ELISA to detect H5 avian influenza virus. Investigational drugs discussed include NEX-DAS-181 (NexBio Inc) and MVA-NP-M1 (The Edward Jenner Institute for Vaccine Research). PMID:19844852

  15. Protective avian influenza in ovo vaccination with non-replicating human adenovirus vector

    PubMed Central

    Toro, Haroldo; Tang, De-chu C.; Suarez, David L.; Sylte, Matt J.; Pfeiffer, Jennifer; Van Kampen, Kent R.

    2009-01-01

    Protective immunity against avian influenza virus was elicited in chickens by single-dose in ovo vaccination with a non-replicating human adenovirus vector encoding an H5N9 avian influenza virus hemagglutinin. Vaccinated chickens were protected against both H5N1 (89% hemagglutinin homology; 68% protection) and H5N2 (94% hemagglutinin homology; 100% protection) highly pathogenic avian influenza virus challenges. Mass-administration of this bird flu vaccine can be streamlined with available robotic in ovo injectors. In addition, adenovirus-vectored vaccines can be produced rapidly and the safety margin of a non-replicating vector is superior to that of a replicating counterpart. Furthermore, this mode of vaccination is compatible with epidemiological surveys of natural avian influenza virus infections. PMID:17055126

  16. Human Infection with Highly Pathogenic A(H7N7) Avian Influenza Virus, Italy, 2013

    PubMed Central

    Rossini, Giada; Facchini, Marzia; Vaccari, Gabriele; Di Trani, Livia; Di Martino, Angela; Gaibani, Paolo; Vocale, Caterina; Cattoli, Giovanni; Bennett, Michael; McCauley, John W.; Rezza, Giovanni; Moro, Maria Luisa; Rangoni, Roberto; Finarelli, Alba Carola; Landini, Maria Paola; Castrucci, Maria Rita; Donatelli, Isabella

    2014-01-01

    During an influenza A(H7N7) virus outbreak among poultry in Italy during August–September 2013, infection with a highly pathogenic A(H7N7) avian influenza virus was diagnosed for 3 poultry workers with conjunctivitis. Genetic analyses revealed that the viruses from the humans were closely related to those from chickens on affected farms. PMID:25271444

  17. H7N9 avian influenza A virus and the perpetual challenge of potential human pandemicity.

    PubMed

    Morens, David M; Taubenberger, Jeffery K; Fauci, Anthony S

    2013-07-09

    ABSTRACT The ongoing H7N9 influenza epizootic in China once again presents us questions about the origin of pandemics and how to recognize them in early stages of development. Over the past ~135 years, H7 influenza viruses have neither caused pandemics nor been recognized as having undergone human adaptation. Yet several unusual properties of these viruses, including their poultry epizootic potential, mammalian adaptation, and atypical clinical syndromes in rarely infected humans, suggest that they may be different from other avian influenza viruses, thus questioning any assurance that the likelihood of human adaptation is low. At the same time, the H7N9 epizootic provides an opportunity to learn more about the mammalian/human adaptational capabilities of avian influenza viruses and challenges us to integrate virologic and public health research and surveillance at the animal-human interface.

  18. Structural basis for preferential avian receptor binding by the human-infecting H10N8 avian influenza virus.

    PubMed

    Wang, Min; Zhang, Wei; Qi, Jianxun; Wang, Fei; Zhou, Jianfang; Bi, Yuhai; Wu, Ying; Sun, Honglei; Liu, Jinhua; Huang, Chaobin; Li, Xiangdong; Yan, Jinghua; Shu, Yuelong; Shi, Yi; Gao, George F

    2015-01-01

    Since December 2013, at least three cases of human infections with H10N8 avian influenza virus have been reported in China, two of them being fatal. To investigate the epidemic potential of H10N8 viruses, we examined the receptor binding property of the first human isolate, A/Jiangxi-Donghu/346/2013 (JD-H10N8), and determined the structures of its haemagglutinin (HA) in complex with both avian and human receptor analogues. Our results suggest that JD-H10N8 preferentially binds the avian receptor and that residue R137-localized within the receptor-binding site of HA-plays a key role in this preferential binding. Compared with the H7N9 avian influenza viruses, JD-H10N8 did not exhibit the enhanced binding to human receptors observed with the prevalent H7N9 virus isolate Anhui-1, but resembled the receptor binding activity of the early-outbreak H7N9 isolate (Shanghai-1). We conclude that the H10N8 virus is a typical avian influenza virus.

  19. Susceptibility of human and avian influenza viruses to human and chicken saliva.

    PubMed

    Limsuwat, Nattavatchara; Suptawiwat, Ornpreya; Boonarkart, Chompunuch; Puthavathana, Pilaipan; Auewarakul, Prasert; Wiriyarat, Witthawat

    2014-05-01

    Oral cavity can be an entry site of influenza virus and saliva is known to contain innate soluble anti-influenza factors. Influenza strains were shown to vary in their susceptibility to those antiviral factors. Whether the susceptibility to the saliva antiviral factors plays any role in the host species specificity of influenza viruses is not known. In this study, the antiviral activity of human and chicken saliva against human and the H5N1 avian influenza viruses were investigated by hemagglutination inhibition (HI) and neutralization (NT) assays. In comparison to human influenza viruses, H5N1 isolates showed reduced susceptibility to human saliva as measured by HI and NT assays. Interestingly, an H5N1 isolate that bind to both α2,3- and α2,6-linked sialic acid showed much higher HI titers with human saliva, suggesting that the susceptibility profile was linked to the receptor-binding preference and the presence of α2,6-linked sialic in human saliva. On the other hand, the H5N1 isolates showed increased HI titers but reduced NT titers to chicken saliva as compared to human influenza isolates. The human salivary antiviral components were characterized by testing the sensitivity to heat, receptor destroying enzyme (RDE), CaCl₂/EDTA dependence, and inhibition by mannan, and shown to be α- and γ-inhibitors. These data suggest that the H5N1 HPAI influenza virus had distinctive susceptibility patterns to human and chicken saliva, which may play some roles in its infectivity and transmissibility in these hosts.

  20. Serological Evidence of Human Infection with Avian Influenza A H7virus in Egyptian Poultry Growers

    PubMed Central

    Gomaa, Mokhtar R.; Kandeil, Ahmed; Kayed, Ahmed S.; Elabd, Mona A.; Zaki, Shaimaa A.; Abu Zeid, Dina; El Rifay, Amira S.; Mousa, Adel A.; Farag, Mohamed M.; McKenzie, Pamela P.; Webby, Richard J.; Ali, Mohamed A.; Kayali, Ghazi

    2016-01-01

    Avian influenza viruses circulate widely in birds, with occasional human infections. Poultry-exposed individuals are considered to be at high risk of infection with avian influenza viruses due to frequent exposure to poultry. Some avian H7 viruses have occasionally been found to infect humans. Seroprevalence of neutralizing antibodies against influenza A/H7N7 virus among poultry-exposed and unexposed individuals in Egypt were assessed during a three-years prospective cohort study. The seroprevalence of antibodies (titer, ≥80) among exposed individuals was 0%, 1.9%, and 2.1% annually while the seroprevalence among the control group remained 0% as measured by virus microneutralization assay. We then confirmed our results using western blot and immunofluorescence assays. Although human infection with H7 in Egypt has not been reported yet, our results suggested that Egyptian poultry growers are exposed to avian H7 viruses. These findings highlight the need for surveillance in the people exposed to poultry to monitor the risk of zoonotic transmission of avian influenza viruses. PMID:27258357

  1. Avian influenza virus in pregnancy.

    PubMed

    Liu, Shelan; Sha, Jianping; Yu, Zhao; Hu, Yan; Chan, Ta-Chien; Wang, Xiaoxiao; Pan, Hao; Cheng, Wei; Mao, Shenghua; Zhang, Run Ju; Chen, Enfu

    2016-07-01

    The unprecedented epizootic of avian influenza viruses, such as H5N1, H5N6, H7N1 and H10N8, has continued to cause disease in humans in recent years. In 2013, another novel influenza A (H7N9) virus emerged in China, and 30% of those patients died. Pregnant women are particularly susceptible to avian influenza and are more likely to develop severe complications and to die, especially when infection occurs in the middle and late trimesters. Viremia is believed to occur infrequently, and thus vertical transmission induced by avian influenza appears to be rare. However, avian influenza increases the risk of adverse pregnancy outcomes, including spontaneous abortion, preterm birth and fatal distress. This review summarises 39 cases of pregnant women and their fetuses from different countries dating back to 1997, including 11, 15 and 13 infections with H7N9, H5N1 and the 2009 pandemic influenza (H1N1), respectively. We analysed the epidemic features, following the geographical, population and pregnancy trimester distributions; underlying diseases; exposure history; medical timelines; human-to-human transmission; pathogenicity and vertical transmission; antivirus treatments; maternal severity and mortality and pregnancy outcome. The common experiences reported in different countries and areas suggest that early identification and treatment are imperative. In the future, vigilant virologic and epidemiologic surveillance systems should be developed to monitor avian influenza viruses during pregnancy. Furthermore, extensive study on the immune mechanisms should be conducted, as this will guide safe, rational immunomodulatory treatment among this high-risk population. Most importantly, we should develop a universal avian influenza virus vaccine to prevent outbreaks of the different subtypes. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27187752

  2. Preferential recognition of avian-like receptors in human influenza A H7N9 viruses.

    PubMed

    Xu, Rui; de Vries, Robert P; Zhu, Xueyong; Nycholat, Corwin M; McBride, Ryan; Yu, Wenli; Paulson, James C; Wilson, Ian A

    2013-12-01

    The 2013 outbreak of avian-origin H7N9 influenza in eastern China has raised concerns about its ability to transmit in the human population. The hemagglutinin glycoprotein of most human H7N9 viruses carries Leu(226), a residue linked to adaptation of H2N2 and H3N2 pandemic viruses to human receptors. However, glycan array analysis of the H7 hemagglutinin reveals negligible binding to humanlike α2-6-linked receptors and strong preference for a subset of avian-like α2-3-linked glycans recognized by all avian H7 viruses. Crystal structures of H7N9 hemagglutinin and six hemagglutinin-glycan complexes have elucidated the structural basis for preferential recognition of avian-like receptors. These findings suggest that the current human H7N9 viruses are poorly adapted for efficient human-to-human transmission.

  3. Avian Influenza A (H7N9) Virus

    MedlinePlus

    ... this page: About CDC.gov . Avian Influenza H5 Viruses in the United States Updates and Publications Information ... Humans Examples of Human Infections with Avian Influenza Viruses Outbreaks Health Care and Laboratorian Guidance HPAI A ...

  4. 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

  5. A Review of the Antiviral Susceptibility of Human and Avian Influenza Viruses over the Last Decade

    PubMed Central

    Oh, Ding Yuan; Hurt, Aeron C.

    2014-01-01

    Antivirals play an important role in the prevention and treatment of influenza infections, particularly in high-risk or severely ill patients. Two classes of influenza antivirals have been available in many countries over the last decade (2004–2013), the adamantanes and the neuraminidase inhibitors (NAIs). During this period, widespread adamantane resistance has developed in circulating influenza viruses rendering these drugs useless, resulting in the reliance on the most widely available NAI, oseltamivir. However, the emergence of oseltamivir-resistant seasonal A(H1N1) viruses in 2008 demonstrated that NAI-resistant viruses could also emerge and spread globally in a similar manner to that seen for adamantane-resistant viruses. Previously, it was believed that NAI-resistant viruses had compromised replication and/or transmission. Fortunately, in 2013, the majority of circulating human influenza viruses remain sensitive to all of the NAIs, but significant work by our laboratory and others is now underway to understand what enables NAI-resistant viruses to retain the capacity to replicate and transmit. In this review, we describe how the susceptibility of circulating human and avian influenza viruses has changed over the last ten years and describe some research studies that aim to understand how NAI-resistant human and avian influenza viruses may emerge in the future. PMID:24800107

  6. [Highly pathogenic avian influenza in poultry (fowl plague); implications for human health].

    PubMed

    Brugere-Picoux, Jeanne

    2005-11-01

    Since 1997, high-pathogenicity avian influenza (HPAI) virus infection in poultry "avian plague" has emerged as a potential threat to human health, with some fatal cases of bird-to-human transmission. These sporadic infections are caused by H7N7 and H5N1 viruses in Europe and Asia, respectively. The persistence of H5N1 viruses in poultry in several Asian countries, and their appearance in Europe, has raised concerns that the virus might mutate or recombine to create a human pandemic influenza A virus. Wild waterfowl are the natural reservoir of all influenza A viruses, and rarely develop the disease. Since 2002, some H5N1 HPAI viruses have become lethal for waterfowl, cats and humans, indicating an expanding host range. Transmission of H5N1 HPAI viruses from domestic poultry back to resistant domestic and wild ducks and to terrestrial birds (sparrows, pigeons, falcons, etc.) has increased the risk of geographic spread in Asia. These viruses spread through fecal contamination of the environment (particularly groundwater). Low-pathogenicity avian influenza (LPAI) viruses cause localized respiratory and gastrointestinal tract infection and, unlike HPAI viruses, are not detected in blood, muscle or eggs. Detection of HPAI viruses in meat, blood and internal organs of chickens and ducks raises public health concerns and underlines the need to thoroughly cook poultry and eggs consumed in Asia. The last case of HPA1 virus infection in France was notified in 1955.

  7. Adaptation of avian influenza A (H6N1) virus from avian to human receptor-binding preference.

    PubMed

    Wang, Fei; Qi, Jianxun; Bi, Yuhai; Zhang, Wei; Wang, Min; Zhang, Baorong; Wang, Ming; Liu, Jinhua; Yan, Jinghua; Shi, Yi; Gao, George F

    2015-06-12

    The receptor-binding specificity of influenza A viruses is a major determinant for the host tropism of the virus, which enables interspecies transmission. In 2013, the first human case of infection with avian influenza A (H6N1) virus was reported in Taiwan. To gather evidence concerning the epidemic potential of H6 subtype viruses, we performed comprehensive analysis of receptor-binding properties of Taiwan-isolated H6 HAs from 1972 to 2013. We propose that the receptor-binding properties of Taiwan-isolated H6 HAs have undergone three major stages: initially avian receptor-binding preference, secondarily obtaining human receptor-binding capacity, and recently human receptor-binding preference, which has been confirmed by receptor-binding assessment of three representative virus isolates. Mutagenesis work revealed that E190V and G228S substitutions are important to acquire the human receptor-binding capacity, and the P186L substitution could reduce the binding to avian receptor. Further structural analysis revealed how the P186L substitution in the receptor-binding site of HA determines the receptor-binding preference change. We conclude that the human-infecting H6N1 evolved into a human receptor preference.

  8. Avian influenza A (H7N9) virus infection in humans: epidemiology, evolution, and pathogenesis.

    PubMed

    Husain, Matloob

    2014-12-01

    New human influenza A virus strains regularly emerge causing seasonal epidemics and occasional pandemics. Lately, several zoonotic avian influenza A strains have been reported to directly infect humans. In early 2013, a novel avian influenza A virus (H7N9) strain was discovered in China to cause severe respiratory disease in humans. Since then, over 450 human cases of H7N9 infection have been discovered and 165 of them have died. Multiple epidemiological, phylogenetic, in vivo, and in vitro studies have been done to determine the origin and pathogenesis of novel H7N9 strain. This article reviews the literature related to the epidemiology, evolution, and pathogenesis of the H7N9 strain since its discovery in February 2013 till August 2014. The data available so far indicate that H7N9 was originated by a two-step reassortment process in birds and transmitted to humans through direct contact with live-bird markets. H7N9 is a low-pathogenic avian virus and contains several molecular signatures for adaptation in mammals. The severity of the respiratory disease caused by novel H7N9 virus in humans can be partly attributed to the age, sex, and underlying medical conditions of the patients. A universal influenza vaccine is not available, though several strain-specific H7N9 candidate vaccine viruses have been developed. Further, novel H7N9 virus is resistant to antiviral drug amantadine and some H7N9 isolates have acquired the resistance to neuraminidase-inhibitors. Therefore, constant surveillance and prompt control measures combined with novel research approaches to develop alternative and effective anti-influenza strategies are needed to overcome influenza A virus.

  9. Reassortment ability of the 2009 pandemic H1N1 influenza virus with circulating human and avian influenza viruses: public health risk implications.

    PubMed

    Stincarelli, Maria; Arvia, Rosaria; De Marco, Maria Alessandra; Clausi, Valeria; Corcioli, Fabiana; Cotti, Claudia; Delogu, Mauro; Donatelli, Isabella; Azzi, Alberta; Giannecchini, Simone

    2013-08-01

    Exploring the reassortment ability of the 2009 pandemic H1N1 (A/H1N1pdm09) influenza virus with other circulating human or avian influenza viruses is the main concern related to the generation of more virulent or new variants having implications for public health. After different coinfection experiments in human A549 cells, by using the A/H1N1pdm09 virus plus one of human seasonal influenza viruses of H1N1 and H3N2 subtype or one of H11, H10, H9, H7 and H1 avian influenza viruses, several reassortant viruses were obtained. Among these, the HA of H1N1 was the main segment of human seasonal influenza virus reassorted in the A/H1N1pdm09 virus backbone. Conversely, HA and each of the three polymerase segments, alone or in combination, of the avian influenza viruses mainly reassorted in the A/H1N1pdm09 virus backbone. Of note, A/H1N1pdm09 viruses that reassorted with HA of H1N1 seasonal human or H11N6 avian viruses or carried different combination of avian origin polymerase segments, exerted a higher replication effectiveness than that of the parental viruses. These results confirm that reassortment of the A/H1N1pdm09 with circulating low pathogenic avian influenza viruses should not be misjudged in the prediction of the next pandemic.

  10. Human H7N9 avian influenza virus infection: a review and pandemic risk assessment

    PubMed Central

    Yiu Lai, Kang; Wing Yiu Ng, George; Fai Wong, Kit; Fan Ngai Hung, Ivan; Kam Fai Hong, Jeffrey; Fan Cheng, Fanny; Kwok Cheung Chan, John

    2013-01-01

    China is undergoing a recent outbreak of a novel H7N9 avian influenza virus (nH7N9) infection that has thus far involved 132 human patients, including 37 deaths. The nH7N9 virus is a reassortant virus originating from the H7N3, H7N9 and H9N2 avian influenza viruses. nH7N9 isolated from humans contains features related to adaptation to humans, including a Q226L mutation in the hemagglutinin cleavage site and E627K and D701N mutations in the PB2 protein. Live poultry markets provide an environment for the emergence, spread and maintenance of nH7N9 as well as for the selection of mutants that facilitate nH7N9 binding to and replication in the human upper respiratory tract. Innate immune suppression conferred by the internal genes of H9N2 may contribute to the virulence of nH7N9. The quail may serve as the intermediate host during the adaptation of avian influenza viruses from domestic waterfowl to gallinaceous poultry, such as chickens and related terrestrial-based species, due to the selection of viral mutants with a short neuraminidase stalk. Infections in chickens, common quails, red-legged partridges and turkeys may select for mutants with human receptor specificity. Infection in Ratitae species may lead to the selection of PB2-E627K and PB2-D701N mutants and the conversion of nH7N9 to a highly pathogenic avian influenza virus. PMID:26038484

  11. Dynamical analysis of the avian-human influenza epidemic model using the semi-analytical method

    NASA Astrophysics Data System (ADS)

    Jabbari, Azizeh; Kheiri, Hossein; Bekir, Ahmet

    2015-03-01

    In this work, we present a dynamic behavior of the avian-human influenza epidemic model by using efficient computational algorithm, namely the multistage differential transform method(MsDTM). The MsDTM is used here as an algorithm for approximating the solutions of the avian-human influenza epidemic model in a sequence of time intervals. In order to show the efficiency of the method, the obtained numerical results are compared with the fourth-order Runge-Kutta method (RK4M) and differential transform method(DTM) solutions. It is shown that the MsDTM has the advantage of giving an analytical form of the solution within each time interval which is not possible in purely numerical techniques like RK4M.

  12. Highly pathogenic avian influenza.

    PubMed

    Swayne, D E; Suarez, D L

    2000-08-01

    Highly pathogenic (HP) avian influenza (AI) (HPAI) is an extremely contagious, multi-organ systemic disease of poultry leading to high mortality, and caused by some H5 and H7 subtypes of type A influenza virus, family Orthomyxoviridae. However, most AI virus strains are mildly pathogenic (MP) and produce either subclinical infections or respiratory and/or reproductive diseases in a variety of domestic and wild bird species. Highly pathogenic avian influenza is a List A disease of the Office International des Epizooties, while MPAI is neither a List A nor List B disease. Eighteen outbreaks of HPAI have been documented since the identification of AI virus as the cause of fowl plague in 1955. Mildly pathogenic avian influenza viruses are maintained in wild aquatic bird reservoirs, occasionally crossing over to domestic poultry and causing outbreaks of mild disease. Highly pathogenic avian influenza viruses do not have a recognised wild bird reservoir, but can occasionally be isolated from wild birds during outbreaks in domestic poultry. Highly pathogenic avian influenza viruses have been documented to arise from MPAI viruses through mutations in the haemagglutinin surface protein. Prevention of exposure to the virus and eradication are the accepted methods for dealing with HPAI. Control programmes, which imply allowing a low incidence of infection, are not an acceptable method for managing HPAI, but have been used during some outbreaks of MPAI. The components of a strategy to deal with MPAI or HPAI include surveillance and diagnosis, biosecurity, education, quarantine and depopulation. Vaccination has been used in some control and eradication programmes for AI.

  13. Avian influenza control strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Control strategies for avian influenza in poultry vary depending on whether the goal is prevention, management, or eradication. Components used in control programs include: 1) education which includes communication, public awareness, and behavioral change, 2) changes to production and marketing sys...

  14. Avian influenza: an agricultural perspective.

    PubMed

    Morgan, Andrea

    2006-11-01

    Recent outbreaks of infection with highly pathogenic H5N1 strains of avian influenza virus in poultry in Asia, Africa, Europe, and the Middle East have raised concern over the potential emergence of a pandemic strain that can easily infect humans and cause serious morbidity and mortality. To prevent and control a national outbreak, the US Department of Agriculture (USDA) conducts measures based on the ecology of avian influenza viruses. To prevent an outbreak in the United States, the USDA conducts surveillance of bird populations, restrictions on bird importation, educational outreach, and regulation of agricultural practices, in collaboration with local, state, and federal organizations. To manage an outbreak, the USDA has in place a well-established emergency management system for optimizing efforts. The USDA also collaborates with international organizations for disease prevention and control in other countries.

  15. FAO-OIE-WHO Joint Technical Consultation on Avian Influenza at the Human-Animal Interface.

    PubMed

    Anderson, Tara; Capua, Ilaria; Dauphin, Gwenaëlle; Donis, Ruben; Fouchier, Ron; Mumford, Elizabeth; Peiris, Malik; Swayne, David; Thiermann, Alex

    2010-05-01

    For the past 10 years, animal health experts and human health experts have been gaining experience in the technical aspects of avian influenza in mostly separate fora. More recently, in 2006, in a meeting of the small WHO Working Group on Influenza Research at the Human Animal Interface (Meeting report available from: http://www.who.int/csr/resources/publications/influenza/WHO_CDS_EPR_GIP_2006_3/en/index.html) in Geneva allowed influenza experts from the animal and public health sectors to discuss together the most recent avian influenza research. Ad hoc bilateral discussions on specific technical issues as well as formal meetings such as the Technical Meeting on HPAI and Human H5N1 Infection (Rome, June, 2007; information available from: http://www.fao.org/avianflu/en/conferences/june2007/index.html) have increasingly brought the sectors together and broadened the understanding of the topics of concern to each sector. The sectors have also recently come together at the broad global level, and have developed a joint strategy document for working together on zoonotic diseases (Joint strategy available from: ftp://ftp.fao.org/docrep/fao/011/ajl37e/ajl37e00.pdf). The 2008 FAO-OIE-WHO Joint Technical Consultation on Avian Influenza at the Human Animal Interface described here was the first opportunity for a large group of influenza experts from the animal and public health sectors to gather and discuss purely technical topics of joint interest that exist at the human-animal interface. During the consultation, three influenza-specific sessions aimed to (1) identify virological characteristics of avian influenza viruses (AIVs) important for zoonotic and pandemic disease, (2) evaluate the factors affecting evolution and emergence of a pandemic influenza strain and identify existing monitoring systems, and (3) identify modes of transmission and exposure sources for human zoonotic influenza infection (including discussion of specific exposure risks by affected countries). A

  16. 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

  17. 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.

  18. Sustained live poultry market surveillance contributes to early warnings for human infection with avian influenza viruses

    PubMed Central

    Fang, Shisong; Bai, Tian; Yang, Lei; Wang, Xin; Peng, Bo; Liu, Hui; Geng, Yijie; Zhang, Renli; Ma, Hanwu; Zhu, Wenfei; Wang, Dayan; Cheng, Jinquan; Shu, Yuelong

    2016-01-01

    Sporadic human infections with the highly pathogenic avian influenza (HPAI) A (H5N6) virus have been reported in different provinces in China since April 2014. From June 2015 to January 2016, routine live poultry market (LPM) surveillance was conducted in Shenzhen, Guangdong Province. H5N6 viruses were not detected until November 2015. The H5N6 virus-positive rate increased markedly beginning in December 2015, and viruses were detected in LPMs in all districts of the city. Coincidently, two human cases with histories of poultry exposure developed symptoms and were diagnosed as H5N6-positive in Shenzhen during late December 2015 and early January 2016. Similar viruses were identified in environmental samples collected in the LPMs and the patients. In contrast to previously reported H5N6 viruses, viruses with six internal genes derived from the H9N2 or H7N9 viruses were detected in the present study. The increased H5N6 virus-positive rate in the LPMs and the subsequent human infections demonstrated that sustained LPM surveillance for avian influenza viruses provides an early warning for human infections. Interventions, such as LPM closures, should be immediately implemented to reduce the risk of human infection with the H5N6 virus when the virus is widely detected during LPM surveillance. PMID:27485495

  19. Sustained live poultry market surveillance contributes to early warnings for human infection with avian influenza viruses.

    PubMed

    Fang, Shisong; Bai, Tian; Yang, Lei; Wang, Xin; Peng, Bo; Liu, Hui; Geng, Yijie; Zhang, Renli; Ma, Hanwu; Zhu, Wenfei; Wang, Dayan; Cheng, Jinquan; Shu, Yuelong

    2016-01-01

    Sporadic human infections with the highly pathogenic avian influenza (HPAI) A (H5N6) virus have been reported in different provinces in China since April 2014. From June 2015 to January 2016, routine live poultry market (LPM) surveillance was conducted in Shenzhen, Guangdong Province. H5N6 viruses were not detected until November 2015. The H5N6 virus-positive rate increased markedly beginning in December 2015, and viruses were detected in LPMs in all districts of the city. Coincidently, two human cases with histories of poultry exposure developed symptoms and were diagnosed as H5N6-positive in Shenzhen during late December 2015 and early January 2016. Similar viruses were identified in environmental samples collected in the LPMs and the patients. In contrast to previously reported H5N6 viruses, viruses with six internal genes derived from the H9N2 or H7N9 viruses were detected in the present study. The increased H5N6 virus-positive rate in the LPMs and the subsequent human infections demonstrated that sustained LPM surveillance for avian influenza viruses provides an early warning for human infections. Interventions, such as LPM closures, should be immediately implemented to reduce the risk of human infection with the H5N6 virus when the virus is widely detected during LPM surveillance. PMID:27485495

  20. Global dynamic analysis of a H7N9 avian-human influenza model in an outbreak region.

    PubMed

    Chen, Yongxue; Wen, Yongxian

    2015-02-21

    In 2013 in China a new type of avian influenza virus, H7N9, began to infect humans and had aroused severe fatality in the infected humans. We know that the spread is from poultry to humans, and the H7N9 avian influenza is low pathogenic in the poultry world but highly pathogenic in the human world, but the transmission mechanism is unclear. Since it has no signs of human-to-human transmission and outbreaks are isolated in some cities in China, in order to investigate the transmission mechanism of human infection with H7N9 avian influenza, an eco-epidemiological model in an outbreak region is proposed and analyzed dynamically. Researches and reports show that gene mutation makes the new virus be capable of infecting humans, therefore the mutation factor is taken into account in the model. The global dynamic analysis is conducted, different thresholds are identified, persistence and global qualitative behaviors are obtained. The impact of H7N9 avian influenza on the people population is concerned. Finally, the numerical simulations are carried out to support the theoretical analysis and to investigate the disease control measures. It seems that we may take people׳s hygiene and prevention awareness factor as a significant policy to achieve the aim of both the disease control and the economic returns.

  1. Investigation of avian influenza infections in wild birds, poultry and humans in Eastern Dongting Lake, China.

    PubMed

    Shi, Jinghong; Gao, Lidong; Zhu, Yun; Chen, Tao; Liu, Yunzhi; Dong, Libo; Liu, Fuqiang; Yang, Hao; Cai, Yahui; Yu, Mingdong; Yao, Yi; Xu, Cuilin; Xiao, Xiangming; Shu, Yuelong

    2014-01-01

    We investigated avian influenza infections in wild birds, poultry, and humans at Eastern Dongting Lake, China. We analyzed 6,621 environmental samples, including fresh fecal and water samples, from wild birds and domestic ducks that were collected from the Eastern Dongting Lake area from November 2011 to April 2012. We also conducted two cross-sectional serological studies in November 2011 and April 2012, with 1,050 serum samples collected from people exposed to wild birds and/or domestic ducks. Environmental samples were tested for the presence of avian influenza virus (AIV) using quantitative PCR assays and virus isolation techniques. Hemagglutination inhibition assays were used to detect antibodies against AIV H5N1, and microneutralization assays were used to confirm these results. Among the environmental samples from wild birds and domestic ducks, AIV prevalence was 5.19 and 5.32%, respectively. We isolated 39 and 5 AIVs from the fecal samples of wild birds and domestic ducks, respectively. Our analysis indicated 12 subtypes of AIV were present, suggesting that wild birds in the Eastern Dongting Lake area carried a diverse array of AIVs with low pathogenicity. We were unable to detect any antibodies against AIV H5N1 in humans, suggesting that human infection with H5N1 was rare in this region.

  2. Sero-prevalence of avian influenza in animals and human in Egypt.

    PubMed

    El-Sayed, A; Prince, A; Fawzy, A; Nadra-Elwgoud; Abdou, M I; Omar, L; Fayed, A; Salem, M

    2013-06-01

    In opposite to most countries, avian influenza virus H5N1 became endemic in Egypt. Since, its first emerge in 2006 in Egypt, the virus could infect different species of birds and animals and even human. Beside the great economic losses to the local poultry industry in Egypt, the virus infected 166 confirmed human cases, 59 cases ended fatally. In the present study, the persistence of the avian influenza in the Egyptian environment was studied. For this purpose, serum samples were collected from human, cattle, buffaloes, sheep, goat, horses, donkeys, swine, sewage rats, stray dogs and stray cats. The sera were collected from Cairo and the surrounding governorates to be examined for the presence of anti-H5N1 antibodies by Haemagglutination Inhibition Test (HI) and ELISA test. Clear differences in the seroprevalence were noticed among different species and also between the results obtained by both techniques indicating the difference in test accuracy. The present data indicate wide spread of the H5N1 virus in the Egyptian environment.

  3. A generic model of contagious disease and its application to human-to-human transmission of avian influenza.

    SciTech Connect

    Hirsch, Gary B.

    2007-03-01

    Modeling contagious diseases has taken on greater importance over the past several years as diseases such as SARS and avian influenza have raised concern about worldwide pandemics. Most models developed to consider projected outbreaks have been specific to a single disease. This paper describes a generic System Dynamics contagious disease model and its application to human-to-human transmission of a mutant version of avian influenza. The model offers the option of calculating rates of new infections over time based either on a fixed ''reproductive number'' that is traditional in contagious disease models or on contact rates for different sub-populations and likelihood of transmission per contact. The paper reports on results with various types of interventions. These results suggest the potential importance of contact tracing, limited quarantine, and targeted vaccination strategies as methods for controlling outbreaks, especially when vaccine supplies may initially be limited and the efficacy of anti-viral drugs uncertain.

  4. Avian influenza in Mexico.

    PubMed

    Villarreal, C

    2009-04-01

    The outbreak of highly pathogenic avian influenza (HPAI) H5N2 in Mexico in 1994 led to a clear increase in biosecurity measures and improvement of intensive poultry production systems. The control and eradication measures implemented were based on active surveillance, disease detection, depopulation of infected farms and prevention of possible contacts (identified by epidemiological investigations), improvement of biosecurity measures, and restriction of the movement of live birds, poultry products, by-products and infected material. In addition, Mexico introduced a massive vaccination programme, which resulted in the eradication of HPAI in a relatively short time in two affected areas that had a high density of commercial poultry.

  5. Chemoenzymatic synthesis of sialoglycopolypeptides as glycomimetics to block infection by avian and human influenza viruses.

    PubMed

    Ogata, Makoto; Hidari, Kazuya I P J; Murata, Takeomi; Shimada, Shizumi; Kozaki, Wataru; Park, Enoch Y; Suzuki, Takashi; Usui, Taichi

    2009-03-18

    We designed a series of gamma-polyglutamic acid (gamma-PGA)-based glycopolypeptides carrying long/short alpha2,3/6 sialylated glycans to act inhibitors of the influenza virus. As an alternative design, sialoglycopolypeptides carrying long-spacer linked glycans were engineered by replacement of the N-acetyllactosamine (LN) unit by an alkyl chain. The structure-activity relationship of the resulting sialoglycopolypeptides with different glycans in the array has been investigated by in vitro and in vivo infection experiments. The avian viruses specifically bound to glycopolypeptides carrying a short sialoglycan with higher affinity than to a long glycan. In contrast, human viruses, preferentially bound not only to long alpha2,3/6 sialylated glycan with LN repeats in the receptors, but also to more spacer-linked glycan in which the inner sugar has been replaced by a nonsugar structural unit such as a pentylamido group. Taken together, our results indicate that a spaced tandem/triplet pentylamido repeat is a good mimetic of a tandem/triplet LN repeat. Our strategy provides a facile way to design strong polymeric inhibitors of infection by avian and human influenza viruses.

  6. A human-infecting H10N8 influenza virus retains a strong preference for avian-type receptors.

    PubMed

    Zhang, Heng; de Vries, Robert P; Tzarum, Netanel; Zhu, Xueyong; Yu, Wenli; McBride, Ryan; Paulson, James C; Wilson, Ian A

    2015-03-11

    Recent avian-origin H10N8 influenza A viruses that have infected humans pose a potential pandemic threat. Alterations in the viral surface glycoprotein, hemagglutinin (HA), typically are required for influenza A viruses to cross the species barrier for adaptation to a new host, but whether H10N8 contains adaptations supporting human infection remains incompletely understood. We investigated whether H10N8 HA can bind human receptors. Sialoside glycan microarray analysis showed that the H10 HA retains a strong preference for avian receptor analogs and negligible binding to human receptor analogs. Crystal structures of H10 HA with avian and human receptor analogs revealed the basis for preferential recognition of avian-like receptors. Furthermore, introduction of mutations into the H10 receptor-binding site (RBS) known to convert other HA subtypes from avian to human receptor specificity failed to switch preference to human receptors. Collectively, these findings suggest that the current H10N8 human isolates are poorly adapted for efficient human-to-human transmission. PMID:25766296

  7. A human-infecting H10N8 influenza virus retains a strong preference for avian-type receptors

    PubMed Central

    Zhu, Xueyong; Yu, Wenli; McBride, Ryan; Paulson, James C.; Wilson, Ian A.

    2015-01-01

    SUMMARY Recent avian-origin H10N8 influenza A viruses that have infected humans pose a potential pandemic threat. Alterations in the viral surface glycoprotein, hemagglutinin (HA), typically allow influenza A viruses to cross the species barrier for adaptation to a new host, but whether H10N8 contains adaptations supporting human infection remains incompletely understood. We investigated whether the H10N8 HA can bind human receptors. Sialoside glycan microarray analysis showed that the H10 HA retains a strong preference for avian receptor analogs and negligible binding to human receptor analogs. Crystal structures of H10 HA with avian and human receptor analogs revealed the basis for preferential recognition of avian-like receptors. Furthermore, introduction of mutations into the H10 receptor-binding site (RBS) known to convert other HA subtypes from avian to human receptor specificity failed to switch the preference to human receptors. Collectively, these findings suggest the current H10N8 human isolates are poorly adapted for efficient human-to-human transmission. PMID:25766296

  8. A human-infecting H10N8 influenza virus retains a strong preference for avian-type receptors.

    PubMed

    Zhang, Heng; de Vries, Robert P; Tzarum, Netanel; Zhu, Xueyong; Yu, Wenli; McBride, Ryan; Paulson, James C; Wilson, Ian A

    2015-03-11

    Recent avian-origin H10N8 influenza A viruses that have infected humans pose a potential pandemic threat. Alterations in the viral surface glycoprotein, hemagglutinin (HA), typically are required for influenza A viruses to cross the species barrier for adaptation to a new host, but whether H10N8 contains adaptations supporting human infection remains incompletely understood. We investigated whether H10N8 HA can bind human receptors. Sialoside glycan microarray analysis showed that the H10 HA retains a strong preference for avian receptor analogs and negligible binding to human receptor analogs. Crystal structures of H10 HA with avian and human receptor analogs revealed the basis for preferential recognition of avian-like receptors. Furthermore, introduction of mutations into the H10 receptor-binding site (RBS) known to convert other HA subtypes from avian to human receptor specificity failed to switch preference to human receptors. Collectively, these findings suggest that the current H10N8 human isolates are poorly adapted for efficient human-to-human transmission.

  9. Oncolytic Activity of Avian Influenza Virus in Human Pancreatic Ductal Adenocarcinoma Cell Lines

    PubMed Central

    Pizzuto, Matteo S.; Silic-Benussi, Micol; Pavone, Silvia; Ciminale, Vincenzo; Capua, Ilaria

    2014-01-01

    ABSTRACT Pancreatic ductal adenocarcinoma (PDA) is the most lethal form of human cancer, with dismal survival rates due to late-stage diagnoses and a lack of efficacious therapies. Building on the observation that avian influenza A viruses (IAVs) have a tropism for the pancreas in vivo, the present study was aimed at testing the efficacy of IAVs as oncolytic agents for killing human PDA cell lines. Receptor characterization confirmed that human PDA cell lines express the alpha-2,3- and the alpha-2,6-linked glycan receptor for avian and human IAVs, respectively. PDA cell lines were sensitive to infection by human and avian IAV isolates, which is consistent with this finding. Growth kinetic experiments showed preferential virus replication in PDA cells over that in a nontransformed pancreatic ductal cell line. Finally, at early time points posttreatment, infection with IAVs caused higher levels of apoptosis in PDA cells than gemcitabine and cisplatin, which are the cornerstone of current therapies for PDA. In the BxPC-3 PDA cell line, apoptosis resulted from the engagement of the intrinsic mitochondrial pathway. Importantly, IAVs did not induce apoptosis in nontransformed pancreatic ductal HPDE6 cells. Using a model based on the growth of a PDA cell line as a xenograft in SCID mice, we also show that a slightly pathogenic avian IAV significantly inhibited tumor growth following intratumoral injection. Taken together, these results are the first to suggest that IAVs may hold promise as future agents of oncolytic virotherapy against pancreatic ductal adenocarcinomas. IMPORTANCE Despite intensive studies aimed at designing new therapeutic approaches, PDA still retains the most dismal prognosis among human cancers. In the present study, we provide the first evidence indicating that avian IAVs of low pathogenicity display a tropism for human PDA cells, resulting in viral RNA replication and a potent induction of apoptosis in vitro and antitumor effects in vivo. These

  10. High-throughput neuraminidase substrate specificity study of human and avian influenza A viruses

    PubMed Central

    Li, Yanhong; Cao, Hongzhi; Dao, Nguyet; Luo, Zheng; Yu, Hai; Chen, Yi; Baumgarth, Nicole; Cardona, Carol; Chen, Xi

    2011-01-01

    Despite the importance of neuraminidase (NA) activity in effective infection by influenza A viruses, limited information exists about the differences of substrate preferences of viral neuraminidases from different hosts or from different strains. Using a high-throughput screening format and a library of twenty α2–3- or α2–6-linked para-nitrophenol-tagged sialylgalactosides, substrate specificity of NAs on thirty-seven strains of human and avian influenza A viruses was studied using intact viral particles. Neuraminidases of all viruses tested cleaved both α2–3- and α2–6-linked sialosides but preferred α2–3-linked ones and the activity was dependent on the terminal sialic acid structure. In contrast to NAs of other subtypes of influenza A viruses which did not cleave 2-keto-3-deoxy-D-glycero-D-galacto-nonulosonic acid (Kdn) or 5-deoxy Kdn (5d–Kdn), NAs of all N7 subtype viruses tested had noticeable hydrolytic activities on α2–3-linked sialosides containing Kdn or 5d–Kdn. Additionally, group 1 NAs showed efficient activity in cleaving N-azidoacetylneuraminic acid from α2 –3-linked sialoside. PMID:21501853

  11. Putative Human and Avian Risk Factors for Avian Influenza Virus Infections in Backyard Poultry in Egypt

    PubMed Central

    Sheta, Basma M.; Fuller, Trevon L.; Larison, Brenda; Njabo, Kevin Y.; Ahmed, Ahmed Samy; Harrigan, Ryan; Chasar, Anthony; Aziz, Soad Abdel; Khidr, Abdel-Aziz A.; Elbokl, Mohamed M.; Habbak, Lotfy Z.; Smith, Thomas B.

    2014-01-01

    Highly pathogenic influenza A virus subtype H5N1 causes significant poultry mortality in the six countries where it is endemic and can also infect humans. Egypt has reported the third highest number of poultry outbreaks (n=1,084) globally. The objective of this cross-sectional study was to identify putative risk factors for H5N1 infections in backyard poultry in 16 villages in Damietta, El Gharbia, Fayoum, and Menofia governorates from 2010–2012. Cloacal and tracheal swabs and serum samples from domestic (n=1242)and wild birds (n=807) were tested for H5N1 via RT-PCR and hemagglutination inhibition, respectively. We measured poultry rearing practices with questionnaires (n=306 households) and contact rates among domestic and wild bird species with scan sampling. Domestic birds (chickens, ducks, and geese, n = 51) in three governorates tested positive for H5N1 by PCR or serology. A regression model identified a significant correlation between H5N1 in poultry and the practice of disposing of dead poultry and poultry feces in the garbage (F = 15.7, p< 0.0001). In addition, contact between domestic and wild birds was more frequent in villages where we detected H5N1 in backyard flocks (F= 29.5, p< 0.0001). PMID:24315038

  12. Putative human and avian risk factors for avian influenza virus infections in backyard poultry in Egypt.

    PubMed

    Sheta, Basma M; Fuller, Trevon L; Larison, Brenda; Njabo, Kevin Y; Ahmed, Ahmed Samy; Harrigan, Ryan; Chasar, Anthony; Abdel Aziz, Soad; Khidr, Abdel-Aziz A; Elbokl, Mohamed M; Habbak, Lotfy Z; Smith, Thomas B

    2014-01-10

    Highly pathogenic influenza A virus subtype H5N1 causes significant poultry mortality in the six countries where it is endemic and can also infect humans. Egypt has reported the third highest number of poultry outbreaks (n=1084) globally. The objective of this cross-sectional study was to identify putative risk factors for H5N1 infections in backyard poultry in 16 villages in Damietta, El Gharbia, Fayoum, and Menofia governorates from 2010-2012. Cloacal and tracheal swabs and serum samples from domestic (n=1242) and wild birds (n=807) were tested for H5N1 via RT-PCR and hemagglutination inhibition, respectively. We measured poultry rearing practices with questionnaires (n=306 households) and contact rates among domestic and wild bird species with scan sampling. Domestic birds (chickens, ducks, and geese, n=51) in three governorates tested positive for H5N1 by PCR or serology. A regression model identified a significant correlation between H5N1 in poultry and the practice of disposing of dead poultry and poultry feces in the garbage (F=15.7, p<0.0001). In addition, contact between domestic and wild birds was more frequent in villages where we detected H5N1 in backyard flocks (F=29.5, p<0.0001).

  13. Avian influenza and pandemic influenza preparedness in Hong Kong.

    PubMed

    Lam, Ping Yan

    2008-06-01

    Avian influenza A H5N1 continues to be a major threat to global public health as it is a likely candidate for the next influenza pandemic. To protect public health and avert potential disruption to the economy, the Hong Kong Special Administrative Region Government has committed substantial effort in preparedness for avian and pandemic influenza. Public health infrastructures for emerging infectious diseases have been developed to enhance command, control and coordination of emergency response. Strategies against avian and pandemic influenza are formulated to reduce opportunities for human infection, detect pandemic influenza timely, and enhance emergency preparedness and response capacity. Key components of the pandemic response include strengthening disease surveillance systems, updating legislation on infectious disease prevention and control, enhancing traveller health measures, building surge capacity, maintaining adequate pharmaceutical stockpiles, and ensuring business continuity during crisis. Challenges from avian and pandemic influenza are not to be underestimated. Implementing quarantine and social distancing measures to contain or mitigate the spread of pandemic influenza is problematic in a highly urbanised city like Hong Kong as they involved complex operational and ethical issues. Sustaining effective risk communication campaigns during interpandemic times is another challenge. Being a member of the global village, Hong Kong is committed to contributing its share of efforts and collaborating with health authorities internationally in combating our common public health enemy.

  14. On avian influenza epidemic models with time delay.

    PubMed

    Liu, Sanhong; Ruan, Shigui; Zhang, Xinan

    2015-12-01

    After the outbreak of the first avian influenza A virus (H5N1) in Hong Kong in 1997, another avian influenza A virus (H7N9) crossed the species barrier in mainland China in 2013 and 2014 and caused more than 400 human cases with a death rate of nearly 40%. In this paper, we take account of the incubation periods of avian influenza A virus and construct a bird-to-human transmission model with different time delays in the avian and human populations combining the survival probability of the infective avian and human populations at the latent time. By analyzing the dynamical behavior of the model, we obtain a threshold value for the prevalence of avian influenza and investigate local and global asymptotical stability of equilibria of the system.

  15. Current situation on highly pathogenic avian influenza

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza is one of the most important diseases affecting the poultry industry worldwide. Avian influenza viruses can cause a range of clinical disease in poultry. Viruses that cause severe disease and mortality are referred to as highly pathogenic avian influenza (HPAI) viruses. The Asian ...

  16. Poultry food products--a source of avian influenza virus transmission to humans?

    PubMed

    Harder, T C; Buda, S; Hengel, H; Beer, M; Mettenleiter, T C

    2016-02-01

    Global human mobility and intercontinental connectivity, expansion of livestock production and encroachment of wildlife habitats by invasive agricultural land use contribute to shape the complexity of influenza epidemiology. The OneHealth approach integrates these and further elements into considerations to improve disease control and prevention. Food of animal origin for human consumption is another integral aspect; if produced from infected livestock such items may act as vehicles of spread of animal pathogens, and, in case of zoonotic agents, as a potential human health hazard. Notifiable zoonotic avian influenza viruses (AIV) have become entrenched in poultry populations in several Asian and northern African countries since 2003. Highly pathogenic (HP) AIV (e.g. H5N1) cause extensive poultry mortality and severe economic losses. HPAIV and low pathogenic AIV (e.g. H7N9) with zoonotic propensities pose risks for human health. More than 1500 human cases of AIV infection have been reported, mainly from regions with endemically infected poultry. Intense human exposure to AIV-infected poultry, e.g. during rearing, slaughtering or processing of poultry, is a major risk factor for acquiring AIV infection. In contrast, human infections through consumption of AIV-contaminated food have not been substantiated. Heating poultry products according to kitchen standards (core temperatures ≥70°C, ≥10 s) rapidly inactivates AIV infectivity and renders fully cooked products safe. Nevertheless, concerted efforts must ensure that poultry products potentially contaminated with zoonotic AIV do not reach the food chain. Stringent and sustained OneHealth measures are required to better control and eventually eradicate, HPAIV from endemic regions.

  17. Poultry food products--a source of avian influenza virus transmission to humans?

    PubMed

    Harder, T C; Buda, S; Hengel, H; Beer, M; Mettenleiter, T C

    2016-02-01

    Global human mobility and intercontinental connectivity, expansion of livestock production and encroachment of wildlife habitats by invasive agricultural land use contribute to shape the complexity of influenza epidemiology. The OneHealth approach integrates these and further elements into considerations to improve disease control and prevention. Food of animal origin for human consumption is another integral aspect; if produced from infected livestock such items may act as vehicles of spread of animal pathogens, and, in case of zoonotic agents, as a potential human health hazard. Notifiable zoonotic avian influenza viruses (AIV) have become entrenched in poultry populations in several Asian and northern African countries since 2003. Highly pathogenic (HP) AIV (e.g. H5N1) cause extensive poultry mortality and severe economic losses. HPAIV and low pathogenic AIV (e.g. H7N9) with zoonotic propensities pose risks for human health. More than 1500 human cases of AIV infection have been reported, mainly from regions with endemically infected poultry. Intense human exposure to AIV-infected poultry, e.g. during rearing, slaughtering or processing of poultry, is a major risk factor for acquiring AIV infection. In contrast, human infections through consumption of AIV-contaminated food have not been substantiated. Heating poultry products according to kitchen standards (core temperatures ≥70°C, ≥10 s) rapidly inactivates AIV infectivity and renders fully cooked products safe. Nevertheless, concerted efforts must ensure that poultry products potentially contaminated with zoonotic AIV do not reach the food chain. Stringent and sustained OneHealth measures are required to better control and eventually eradicate, HPAIV from endemic regions. PMID:26686812

  18. Virus-neutralizing antibody response of mice to consecutive infection with human and avian influenza A viruses.

    PubMed

    Janulíková, J; Stropkovská, A; Bobišová, Z; Košík, I; Mucha, V; Kostolanský, F; Varečková, E

    2015-06-01

    In this work we simulated in a mouse model a naturally occurring situation of humans, who overcame an infection with epidemic strains of influenza A, and were subsequently exposed to avian influenza A viruses (IAV). The antibody response to avian IAV in mice previously infected with human IAV was analyzed. We used two avian IAV (A/Duck/Czechoslovakia/1956 (H4N6) and the attenuated virus rA/Viet Nam/1203-2004 (H5N1)) as well as two human IAV isolates (virus A/Mississippi/1/1985 (H3N2) of medium virulence and A/Puerto Rico/8/1934 (H1N1) of high virulence). Two repeated doses of IAV of H4 or of H5 virus elicited virus-specific neutralizing antibodies in mice. Exposure of animals previously infected with human IAV (of H3 or H1 subtype) to IAV of H4 subtype led to the production of antibodies neutralizing H4 virus in a level comparable with the level of antibodies against the human IAV used for primary infection. In contrast, no measurable levels of virus-neutralizing (VN) antibodies specific to H5 virus were detected in mice infected with H5 virus following a previous infection with human IAV. In both cases the secondary infection with avian IAV led to a significant increase of the titer of VN antibodies specific to the corresponding human virus used for primary infection. Moreover, cross-reactive HA2-specific antibodies were also induced by sequential infection. By virtue of these results we suggest that the differences in the ability of avian IAV to induce specific antibodies inhibiting virus replication after previous infection of mice with human viruses can have an impact on the interspecies transmission and spread of avian IAV in the human population.

  19. Virus-neutralizing antibody response of mice to consecutive infection with human and avian influenza A viruses.

    PubMed

    Janulíková, J; Stropkovská, A; Bobišová, Z; Košík, I; Mucha, V; Kostolanský, F; Varečková, E

    2015-06-01

    In this work we simulated in a mouse model a naturally occurring situation of humans, who overcame an infection with epidemic strains of influenza A, and were subsequently exposed to avian influenza A viruses (IAV). The antibody response to avian IAV in mice previously infected with human IAV was analyzed. We used two avian IAV (A/Duck/Czechoslovakia/1956 (H4N6) and the attenuated virus rA/Viet Nam/1203-2004 (H5N1)) as well as two human IAV isolates (virus A/Mississippi/1/1985 (H3N2) of medium virulence and A/Puerto Rico/8/1934 (H1N1) of high virulence). Two repeated doses of IAV of H4 or of H5 virus elicited virus-specific neutralizing antibodies in mice. Exposure of animals previously infected with human IAV (of H3 or H1 subtype) to IAV of H4 subtype led to the production of antibodies neutralizing H4 virus in a level comparable with the level of antibodies against the human IAV used for primary infection. In contrast, no measurable levels of virus-neutralizing (VN) antibodies specific to H5 virus were detected in mice infected with H5 virus following a previous infection with human IAV. In both cases the secondary infection with avian IAV led to a significant increase of the titer of VN antibodies specific to the corresponding human virus used for primary infection. Moreover, cross-reactive HA2-specific antibodies were also induced by sequential infection. By virtue of these results we suggest that the differences in the ability of avian IAV to induce specific antibodies inhibiting virus replication after previous infection of mice with human viruses can have an impact on the interspecies transmission and spread of avian IAV in the human population. PMID:26104333

  20. Novel Avian Influenza A (H7N9) Virus Induces Impaired Interferon Responses in Human Dendritic Cells

    PubMed Central

    Arilahti, Veera; Mäkelä, Sanna M.; Tynell, Janne; Julkunen, Ilkka; Österlund, Pamela

    2014-01-01

    In March 2013 a new avian influenza A(H7N9) virus emerged in China and infected humans with a case fatality rate of over 30%. Like the highly pathogenic H5N1 virus, H7N9 virus is causing severe respiratory distress syndrome in most patients. Based on genetic analysis this avian influenza A virus shows to some extent adaptation to mammalian host. In the present study, we analyzed the activation of innate immune responses by this novel H7N9 influenza A virus and compared these responses to those induced by the avian H5N1 and seasonal H3N2 viruses in human monocyte-derived dendritic cells (moDCs). We observed that in H7N9 virus-infected cells, interferon (IFN) responses were weak although the virus replicated as well as the H5N1 and H3N2 viruses in moDCs. H7N9 virus-induced expression of pro-inflammatory cytokines remained at a significantly lower level as compared to H5N1 virus-induced “cytokine storm” seen in human moDCs. However, the H7N9 virus was extremely sensitive to the antiviral effects of IFN-α and IFN-β in pretreated cells. Our data indicates that different highly pathogenic avian viruses may show considerable differences in their ability to induce host antiviral responses in human primary cell models such as moDCs. The unexpected appearance of the novel H7N9 virus clearly emphasizes the importance of the global influenza surveillance system. It is, however, equally important to systematically characterize in normal human cells the replication capacity of the new viruses and their ability to induce and respond to natural antiviral substances such as IFNs. PMID:24804732

  1. The history of avian influenza.

    PubMed

    Lupiani, Blanca; Reddy, Sanjay M

    2009-07-01

    The first description of avian influenza (AI) dates back to 1878 in northern Italy, when Perroncito [Perroncito E. Epizoozia tifoide nei gallinacei. Annali Accad Agri Torino 1878;21:87-126] described a contagious disease of poultry associated with high mortality. The disease, termed "fowl plague", was initially confused with the acute septicemic form of fowl cholera. However, in 1880, soon after its first description, Rivolta and Delprato [as reported by Stubs EL. Fowl pest, In: Biester HE, Devries L, editors. Diseases of poultry. 1st ed. Ames, IO: Iowa State College Press; 1943. p. 493-502] showed it to be different from fowl cholera, based on clinical and pathological properties, and called it Typhus exudatious gallinarum. In 1901, Centanni and Savunzzi [Centanni E, Savonuzzi E, La peste aviaria I & II, Communicazione fatta all'accademia delle scienze mediche e naturali de Ferrara, 1901] determined that fowl plague was caused by a filterable virus; however, it was not until 1955 that the classical fowl plague virus was shown to be a type A influenza virus based on the presence of type A influenza virus type-specific ribonucleoprotein [Schäfer W. Vergleichender sero-immunologische Untersuchungen über die Viren der Influenza und klassischen Geflügelpest. Z Naturf 1955;10b:81-91]. The term fowl plague was substituted by the more appropriate term highly pathogenic avian influenza (HPAI) at the First International Symposium on Avian Influenza [Proceedings of the First International Symposium on Avian Influenza. Beltsville, MD. 1981, Avian Dis 47 (Special Issue) 2003.] and will be used throughout this review when referring to any previously described fowl plague virus.

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

    PubMed

    To, Kelvin Kw; Ng, Kenneth Hl; Que, Tak-Lun; Chan, Jacky Mc; Tsang, Kay-Yan; Tsang, Alan Kl; Chen, Honglin; Yuen, Kwok-Yung

    2012-09-01

    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.

  3. 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

  4. Seroprevalence of Antibodies to Avian Influenza Virus A (H5N1) among Residents of Villages with Human Cases, Thailand, 20051

    PubMed Central

    Laosiritaworn, Yongjua; Phuthavathana, Pilaipan; Uyeki, Timothy M.; O’Reilly, Michael; Yampikulsakul, Nattaphon; Phurahong, Sumreung; Poorak, Phisanu; Prasertsopon, Jarunee; Kularb, Rumporn; Nateerom, Kannika; Sawanpanyalert, Narumol; Jiraphongsa, Chuleeporn

    2009-01-01

    In 2005, we assessed the seroprevalence of neutralizing antibodies to avian influenza virus A (H5N1) among 901 residents of 4 villages in Thailand where at least 1 confirmed human case of influenza (H5N1) had occurred during 2004. Although 68.1% of survey participants (median age 40 years) were exposed to backyard poultry and 25.7% were exposed to sick or dead chickens, all participants were seronegative for influenza virus (H5N1). PMID:19402962

  5. Avian influenza virus RNA extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficient extraction and purification of viral RNA is critical for down-stream molecular applications whether it is the sensitive and specific detection of virus in clinical samples, virus gene cloning and expression, or quantification of avian influenza (AI) virus by molecular methods from expe...

  6. Prevalence and control of H7 avian influenza viruses in birds and humans.

    PubMed

    Abdelwhab, E M; Veits, J; Mettenleiter, T C

    2014-05-01

    The H7 subtype HA gene has been found in combination with all nine NA subtype genes. Most exhibit low pathogenicity and only rarely high pathogenicity in poultry (and humans). During the past few years infections of poultry and humans with H7 subtypes have increased markedly. This review summarizes the emergence of avian influenza virus H7 subtypes in birds and humans, and the possibilities of its control in poultry. All H7Nx combinations were reported from wild birds, the natural reservoir of the virus. Geographically, the most prevalent subtype is H7N7, which is endemic in wild birds in Europe and was frequently reported in domestic poultry, whereas subtype H7N3 is mostly isolated from the Americas. In humans, mild to fatal infections were caused by subtypes H7N2, H7N3, H7N7 and H7N9. While infections of humans have been associated mostly with exposure to domestic poultry, infections of poultry have been linked to wild birds or live-bird markets. Generally, depopulation of infected poultry was the main control tool; however, inactivated vaccines were also used. In contrast to recent cases caused by subtype H7N9, human infections were usually self-limiting and rarely required antiviral medication. Close genetic and antigenic relatedness of H7 viruses of different origins may be helpful in development of universal vaccines and diagnostics for both animals and humans. Due to the wide spread of H7 viruses and their zoonotic importance more research is required to better understand the epidemiology, pathobiology and virulence determinants of these viruses and to develop improved control tools.

  7. Pandemic Threat Posed by Avian Influenza A Viruses

    PubMed Central

    Horimoto, Taisuke; Kawaoka, Yoshihiro

    2001-01-01

    Influenza pandemics, defined as global outbreaks of the disease due to viruses with new antigenic subtypes, have exacted high death tolls from human populations. The last two pandemics were caused by hybrid viruses, or reassortants, that harbored a combination of avian and human viral genes. Avian influenza viruses are therefore key contributors to the emergence of human influenza pandemics. In 1997, an H5N1 influenza virus was directly transmitted from birds in live poultry markets in Hong Kong to humans. Eighteen people were infected in this outbreak, six of whom died. This avian virus exhibited high virulence in both avian and mammalian species, causing systemic infection in both chickens and mice. Subsequently, another avian virus with the H9N2 subtype was directly transmitted from birds to humans in Hong Kong. Interestingly, the genes encoding the internal proteins of the H9N2 virus are genetically highly related to those of the H5N1 virus, suggesting a unique property of these gene products. The identification of avian viruses in humans underscores the potential of these and similar strains to produce devastating influenza outbreaks in major population centers. Although highly pathogenic avian influenza viruses had been identified before the 1997 outbreak in Hong Kong, their devastating effects had been confined to poultry. With the Hong Kong outbreak, it became clear that the virulence potential of these viruses extended to humans. PMID:11148006

  8. [Comparative study of the differential susceptibility of different cell lines to pandemic H1N1v influenza viruses and avian influenza, swine influenza, and human influenza viruses].

    PubMed

    Danilenko, D M; Smirnova, T D; Gudkova, T M; Eropkin, M Iu; Kiselev, O I

    2011-01-01

    The proliferation characteristics of influenza viruses of different origin were tested in various human and animal cell cultures. Pandemic H1N1v influenza and swine influenza viruses were shown to have a low infectious activity in virtually all the test lines. In spite of this, the replication of this group of viruses may be detected by de novo NP synthesis. These viruses are able to activate programmed cell death. Moreover, a low inoculative virus dose exerts a stimulating effect on cell proliferation in both suspension and monolayer cell lines.

  9. DIVA vaccination strategies for avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccination for both low pathogenic and highly pathogenic avian influenza is commonly used for countries that have been endemic for avian influenza influenza virus, but stamping out policies are common for countries that are normally free of the disease. Stamping out policies of euthanizing infecte...

  10. Avian-to-human transmission of the PB1 gene of influenza A viruses in the 1957 and 1968 pandemics.

    PubMed Central

    Kawaoka, Y; Krauss, S; Webster, R G

    1989-01-01

    We determined the origin and evolutionary pathways of the PB1 genes of influenza A viruses responsible for the 1957 and 1968 human pandemics and obtained information on the variable or conserved region of the PB1 protein. The evolutionary tree constructed from nucleotide sequences suggested the following: (i) the PB1 gene of the 1957 human pandemic strain, A/Singapore/1/57 (H2N2), was probably introduced from avian species and was maintained in humans until 1968; (ii) in the 1968 pandemic strain, A/NT/60/68 (H3N2), the PB1 gene was not derived from the previously circulating virus in humans but probably from another avian virus; and (iii) a current human H3N2 virus inherited the PB1 gene from an A/NT/60/68-like virus. Nucleotide sequence analysis also showed that the avian PB1 gene was introduced into pigs. Hence, transmission of the PB1 gene from avian to mammalian species is a relatively frequent event. Comparative analysis of deduced amino acid sequences disclosed highly conserved regions in PB1 proteins, which may be key structures required for PB1 activities. PMID:2795713

  11. An overview of the characteristics of the novel avian influenza A H7N9 virus in humans

    PubMed Central

    Tan, Kei-Xian; Jacob, Sabrina A.; Chan, Kok-Gan; Lee, Learn-Han

    2015-01-01

    The novel avian influenza A H7N9 virus which caused the first human infection in Shanghai, China; was reported on the 31st of March 2013 before spreading rapidly to other Chinese provinces and municipal cities. This is the first time the low pathogenic avian influenza A virus has caused human infections and deaths; with cases of severe respiratory disease with pneumonia being reported. There were 440 confirmed cases with 122 fatalities by 16 May 2014; with a fatality risk of ∼28%. The median age of patients was 61 years with a male-to-female ratio of 2.4:1. The main source of infection was identified as exposure to poultry and there is so far no definitive evidence of sustained person-to-person transmission. The neuraminidase inhibitors, namely oseltamivir, zanamivir, and peramivir; have shown good efficacy in the management of the novel H7N9 virus. Treatment is recommended for all hospitalized patients, and for confirmed and probable outpatient cases; and should ideally be initiated within 48 h of the onset of illness for the best outcome. Phylogenetic analysis found that the novel H7N9 virus is avian in origin and evolved from multiple reassortments of at least four origins. Indeed the novel H7N9 virus acquired human adaptation via mutations in its eight RNA gene segments. Enhanced surveillance and effective global control are essential to prevent pandemic outbreaks of the novel H7N9 virus. PMID:25798131

  12. An overview of the characteristics of the novel avian influenza A H7N9 virus in humans.

    PubMed

    Tan, Kei-Xian; Jacob, Sabrina A; Chan, Kok-Gan; Lee, Learn-Han

    2015-01-01

    The novel avian influenza A H7N9 virus which caused the first human infection in Shanghai, China; was reported on the 31st of March 2013 before spreading rapidly to other Chinese provinces and municipal cities. This is the first time the low pathogenic avian influenza A virus has caused human infections and deaths; with cases of severe respiratory disease with pneumonia being reported. There were 440 confirmed cases with 122 fatalities by 16 May 2014; with a fatality risk of ∼28%. The median age of patients was 61 years with a male-to-female ratio of 2.4:1. The main source of infection was identified as exposure to poultry and there is so far no definitive evidence of sustained person-to-person transmission. The neuraminidase inhibitors, namely oseltamivir, zanamivir, and peramivir; have shown good efficacy in the management of the novel H7N9 virus. Treatment is recommended for all hospitalized patients, and for confirmed and probable outpatient cases; and should ideally be initiated within 48 h of the onset of illness for the best outcome. Phylogenetic analysis found that the novel H7N9 virus is avian in origin and evolved from multiple reassortments of at least four origins. Indeed the novel H7N9 virus acquired human adaptation via mutations in its eight RNA gene segments. Enhanced surveillance and effective global control are essential to prevent pandemic outbreaks of the novel H7N9 virus. PMID:25798131

  13. Emergence in China of human disease due to avian influenza A(H10N8)--cause for concern?

    PubMed

    To, Kelvin K W; Tsang, Alan K L; Chan, Jasper F W; Cheng, Vincent C C; Chen, Honglin; Yuen, Kwok-Yung

    2014-03-01

    In December 2013, China reported the first human case of avian influenza A(H10N8). A 73-year-old female with chronic diseases who had visited a live poultry market succumbed with community-acquired pneumonia. While human infections with avian influenza viruses are usually associated with subtypes prevalent in poultries, A(H10N8) isolates were mostly found in migratory birds and only recently in poultries. Although not possible to predict whether this single intrusion by A(H10N8) is an accident or the start of another epidemic like the preceding A(H7N9) and A(H5N1), several features suggest that A(H10N8) is a potential threat to humans. Recombinant H10 could attach to human respiratory epithelium, and A(H10N4) virus could cause severe infections in minks and chickens. A(H10N8) viruses contain genetic markers for mammalian adaptation and virulence in the haemagglutinin (A135T, S138A[H3 numbering]), M1(N30D, T215A), NS1(P42S) and PB2(E627K) protein. Studies on this human A(H10N8) isolate will reveal its adaptability to humans. Clinicians should alert the laboratory to test for A(H5,6,7,9,10) viruses in patients with epidemiological exposure in endemic geographical areas especially when human influenza A(H1,3) and B are negative. Vigilant virological and serological surveillance for A(H10N8) in human, poultry and wild bird is important for following the trajectory of this emerging influenza virus.

  14. Avian Influenza in Birds

    MedlinePlus

    ... and even kill certain domesticated bird species including chickens, ducks, and turkeys. Infected birds can shed avian ... virus’ ability to cause disease and mortality in chickens in a laboratory setting [2.5 MB, 64 ...

  15. Avian and pandemic human influenza policy in South-East Asia: the interface between economic and public health imperatives.

    PubMed

    Pongcharoensuk, Petcharat; Adisasmito, Wiku; Sat, Le Minh; Silkavute, Pornpit; Muchlisoh, Lilis; Cong Hoat, Pham; Coker, Richard

    2012-08-01

    The aim of this study was to analyse the contemporary policies regarding avian and human pandemic influenza control in three South-East Asia countries: Thailand, Indonesia and Vietnam. An analysis of poultry vaccination policy was used to explore the broader policy of influenza A H5N1 control in the region. The policy of antiviral stockpiling with oseltamivir, a scarce regional resource, was used to explore human pandemic influenza preparedness policy. Several policy analysis theories were applied to analyse the debate on the use of vaccination for poultry and stockpiling of antiviral drugs in each country case study. We conducted a comparative analysis across emergent themes. The study found that whilst Indonesia and Vietnam introduced poultry vaccination programmes, Thailand rejected this policy approach. By contrast, all three countries adopted similar strategic policies for antiviral stockpiling in preparation. In relation to highly pathogenic avian influenza, economic imperatives are of critical importance. Whilst Thailand's poultry industry is large and principally an export economy, Vietnam's and Indonesia's are for domestic consumption. The introduction of a poultry vaccination policy in Thailand would have threatened its potential to trade and had a major impact on its economy. Powerful domestic stakeholders in Vietnam and Indonesia, by contrast, were concerned less about international trade and more about maintaining a healthy domestic poultry population. Evidence on vaccination was drawn upon differently depending upon strategic economic positioning either to support or oppose the policy. With influenza A H5N1 endemic in some countries of the region, these policy differences raise questions around regional coherence of policies and the pursuit of an agreed overarching goal, be that eradication or mitigation. Moreover, whilst economic imperatives have been critically important in guiding policy formulation in the agriculture sector, questions arise

  16. Human infection with an avian influenza A (H9N2) virus in the middle region of China.

    PubMed

    Huang, Yiwei; Li, Xiaodan; Zhang, Hong; Chen, Bozhong; Jiang, Yonglin; Yang, Lei; Zhu, Wenfei; Hu, Shixiong; Zhou, Siyu; Tang, Yunli; Xiang, Xingyu; Li, Fangcai; Li, Wenchao; Gao, Lidong

    2015-10-01

    During the epidemic period of the novel H7N9 viruses, an influenza A (H9N2) virus was isolated from a 7-year-old boy with influenza-like illness in Yongzhou city of Hunan province in November 2013. To identify the possible source of infection, environmental specimens collected from local live poultry markets epidemiologically linked to the human case in Yongzhou city were tested for influenza type A and its subtypes H5, H7, and H9 using real-time RT-PCR methods as well as virus isolation, and four other H9N2 viruses were isolated. The real-time RT-PCR results showed that the environment was highly contaminated with avian influenza H9 subtype viruses (18.0%). Sequencing analyses revealed that the virus isolated from the patient, which was highly similar (98.5-99.8%) to one of isolates from environment in complete genome sequences, was of avian origin. Based on phylogenetic and antigenic analyses, it belonged to genotype S and Y280 lineage. In addition, the virus exhibited high homology (95.7-99.5%) of all six internal gene lineages with the novel H7N9 and H10N8 viruses which caused epidemic and endemic in China. Meanwhile, it carried several mammalian adapted molecular residues including Q226L in HA protein, L13P in PB1 protein, K356R, S409N in PA protein, V15I in M1 protein, I28V, L55F in M2 protein, and E227K in NS protein. These findings reinforce the significance of continuous surveillance of H9N2 influenza viruses. PMID:25965534

  17. Human infection with an avian influenza A (H9N2) virus in the middle region of China.

    PubMed

    Huang, Yiwei; Li, Xiaodan; Zhang, Hong; Chen, Bozhong; Jiang, Yonglin; Yang, Lei; Zhu, Wenfei; Hu, Shixiong; Zhou, Siyu; Tang, Yunli; Xiang, Xingyu; Li, Fangcai; Li, Wenchao; Gao, Lidong

    2015-10-01

    During the epidemic period of the novel H7N9 viruses, an influenza A (H9N2) virus was isolated from a 7-year-old boy with influenza-like illness in Yongzhou city of Hunan province in November 2013. To identify the possible source of infection, environmental specimens collected from local live poultry markets epidemiologically linked to the human case in Yongzhou city were tested for influenza type A and its subtypes H5, H7, and H9 using real-time RT-PCR methods as well as virus isolation, and four other H9N2 viruses were isolated. The real-time RT-PCR results showed that the environment was highly contaminated with avian influenza H9 subtype viruses (18.0%). Sequencing analyses revealed that the virus isolated from the patient, which was highly similar (98.5-99.8%) to one of isolates from environment in complete genome sequences, was of avian origin. Based on phylogenetic and antigenic analyses, it belonged to genotype S and Y280 lineage. In addition, the virus exhibited high homology (95.7-99.5%) of all six internal gene lineages with the novel H7N9 and H10N8 viruses which caused epidemic and endemic in China. Meanwhile, it carried several mammalian adapted molecular residues including Q226L in HA protein, L13P in PB1 protein, K356R, S409N in PA protein, V15I in M1 protein, I28V, L55F in M2 protein, and E227K in NS protein. These findings reinforce the significance of continuous surveillance of H9N2 influenza viruses.

  18. Host-Specific and Segment-Specific Evolutionary Dynamics of Avian and Human Influenza A Viruses: A Systematic Review.

    PubMed

    Kim, Kiyeon; Omori, Ryosuke; Ueno, Keisuke; Iida, Sayaka; Ito, Kimihito

    2016-01-01

    Understanding the evolutionary dynamics of influenza viruses is essential to control both avian and human influenza. Here, we analyze host-specific and segment-specific Tajima's D trends of influenza A virus through a systematic review using viral sequences registered in the National Center for Biotechnology Information. To avoid bias from viral population subdivision, viral sequences were stratified according to their sampling locations and sampling years. As a result, we obtained a total of 580 datasets each of which consists of nucleotide sequences of influenza A viruses isolated from a single population of hosts at a single sampling site within a single year. By analyzing nucleotide sequences in the datasets, we found that Tajima's D values of viral sequences were different depending on hosts and gene segments. Tajima's D values of viruses isolated from chicken and human samples showed negative, suggesting purifying selection or a rapid population growth of the viruses. The negative Tajima's D values in rapidly growing viral population were also observed in computer simulations. Tajima's D values of PB2, PB1, PA, NP, and M genes of the viruses circulating in wild mallards were close to zero, suggesting that these genes have undergone neutral selection in constant-sized population. On the other hand, Tajima's D values of HA and NA genes of these viruses were positive, indicating HA and NA have undergone balancing selection in wild mallards. Taken together, these results indicated the existence of unknown factors that maintain viral subtypes in wild mallards.

  19. The global nature of avian influenza

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus is a global virus which knows no geographic boundaries, has no political agenda, and can infect poultry irrespective of their agricultural or anthropocentric production systems. Avian influenza viruses or evidence of their infection have been detected in poultry and wild birds...

  20. 76 FR 24793 - Highly Pathogenic Avian Influenza

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-03

    ... (76 FR 4046-4056, Docket No. APHIS-2006-0074) an interim rule that amended the regulations governing... Inspection Service 9 CFR Parts 93, 94, and 95 RIN 0579-AC36 Highly Pathogenic Avian Influenza AGENCY: Animal... products from regions where any subtype of highly pathogenic avian influenza is considered to exist....

  1. Human infection with a highly pathogenic avian influenza A (H5N6) virus in Yunnan province, China.

    PubMed

    Xu, Wen; Li, Hong; Jiang, Li

    2016-01-01

    Highly pathogenic avian influenza A H5N6 virus has caused four human infections in China. This study reports the preliminary findings of the first known human case of H5N6 in Yunnan province. The patient initially developed symptoms of sore throat and coughing on 27 January 2015. The disease rapidly progressed to severe pneumonia, multiple organ dysfunctions and acute respiratory distress syndrome and the patient died on 6 February. Virological analysis determined that the virus belonged to H5 clade 2.3.4.4 and it has obtained partial ability for mammalian adaptation and amantadine resistance. Environmental investigation found H5 in 63% of the samples including poultry faeces, tissues, cage surface swabs and sewage from local live poultry markets by real-time RT-PCR. These findings suggest that the expanding and enhancing of surveillance in both avian and humans are necessary to monitor the evolution of H5 influenza virus and to facilitate early detection of suspected cases. PMID:27030920

  2. Ambient Influenza and Avian Influenza Virus during Dust Storm Days and Background Days

    PubMed Central

    Chen, Pei-Shih; Tsai, Feng Ta; Lin, Chien Kun; Yang, Chun-Yuh; Chan, Chang-Chuan; Young, Chea-Yuan; Lee, Chien-Hung

    2010-01-01

    Background The spread of influenza and highly pathogenic avian influenza (H5N1) presents a significant threat to human health. Avian influenza outbreaks in downwind areas of Asian dust storms (ADS) suggest that viruses might be transported by dust storms. Objectives We developed a technique to measure ambient influenza and avian influenza viruses. We then used this technique to measure concentrations of these viruses on ADS days and background days, and to assess the relationships between ambient influenza and avian influenza viruses, and air pollutants. Methods A high-volume air sampler was used in parallel with a filter cassette to evaluate spiked samples and unspiked samples. Then, air samples were monitored during ADS seasons using a filter cassette coupled with a real-time quantitative polymerase chain reaction (qPCR) assay. Air samples were monitored during ADS season (1 January to 31 May 2006). Results We successfully quantified ambient influenza virus using the filtration/real-time qPCR method during ADS days and background days. To our knowledge, this is the first report describing the concentration of influenza virus in ambient air. In both the spiked and unspiked samples, the concentration of influenza virus sampled using the filter cassette was higher than that using the high-volume sampler. The concentration of ambient influenza A virus was significantly higher during the ADS days than during the background days. Conclusions Our data imply the possibility of long-range transport of influenza virus. PMID:20435545

  3. Modelling the species jump: towards assessing the risk of human infection from novel avian influenzas.

    PubMed

    Hill, A A; Dewé, T; Kosmider, R; Von Dobschuetz, S; Munoz, O; Hanna, A; Fusaro, A; De Nardi, M; Howard, W; Stevens, K; Kelly, L; Havelaar, A; Stärk, K

    2015-09-01

    The scientific understanding of the driving factors behind zoonotic and pandemic influenzas is hampered by complex interactions between viruses, animal hosts and humans. This complexity makes identifying influenza viruses of high zoonotic or pandemic risk, before they emerge from animal populations, extremely difficult and uncertain. As a first step towards assessing zoonotic risk of influenza, we demonstrate a risk assessment framework to assess the relative likelihood of influenza A viruses, circulating in animal populations, making the species jump into humans. The intention is that such a risk assessment framework could assist decision-makers to compare multiple influenza viruses for zoonotic potential and hence to develop appropriate strain-specific control measures. It also provides a first step towards showing proof of principle for an eventual pandemic risk model. We show that the spatial and temporal epidemiology is as important in assessing the risk of an influenza A species jump as understanding the innate molecular capability of the virus. We also demonstrate data deficiencies that need to be addressed in order to consistently combine both epidemiological and molecular virology data into a risk assessment framework. PMID:26473042

  4. Global dynamics of avian influenza epidemic models with psychological effect.

    PubMed

    Liu, Sanhong; Pang, Liuyong; Ruan, Shigui; Zhang, Xinan

    2015-01-01

    Cross-sectional surveys conducted in Thailand and China after the outbreaks of the avian influenza A H5N1 and H7N9 viruses show a high degree of awareness of human avian influenza in both urban and rural populations, a higher level of proper hygienic practice among urban residents, and in particular a dramatically reduced number of visits to live markets in urban population after the influenza A H7N9 outbreak in China in 2013. In this paper, taking into account the psychological effect toward avian influenza in the human population, a bird-to-human transmission model in which the avian population exhibits saturation effect is constructed. The dynamical behavior of the model is studied by using the basic reproduction number. The results demonstrate that the saturation effect within avian population and the psychological effect in human population cannot change the stability of equilibria but can affect the number of infected humans if the disease is prevalent. Numerical simulations are given to support the theoretical results and sensitivity analyses of the basic reproduction number in terms of model parameters that are performed to seek for effective control measures for avian influenza.

  5. Clinical, epidemiological and virological characteristics of the first detected human case of avian influenza A(H5N6) virus

    PubMed Central

    Zhang, Rusheng; Chen, Tianmu; Ou, Xinhua; Liu, Ruchun; Yang, Yang; Ye, Wen; Chen, Jingfang; Yao, Dong; Sun, Biancheng; Zhang, Xixing; Zhou, Jianxiang; Sun, Yan; Chen, Faming; Wang, Shi-Ping

    2016-01-01

    A human infection with novel avian influenza A H5N6 virus emerged in Changsha city, China in February, 2014. This is the first detected human case among all human cases identified from 2014 to early 2016. We obtained and summarized clinical, epidemiological, and virological data from this patient. Complete genome of the virus was determined and compared to other avian influenza viruses via the construction of phylogenetic trees using the neighbor-joining approach. A girl aged five and half years developed fever and mild respiratory symptoms on Feb. 16, 2014 and visited hospital on Feb. 17. Throat swab specimens were obtained from the patient and a novel reassortant avian influenza A H5N6 virus was detected. All eight viral gene segments were of avian origin. The hemagglutinin (HA) and neuraminidase (NA) gene segments were closely related to A/duck/Sichuan/NCXN11/2014(H5N1) and A/chicken/Jiangxi/12782/2014(H10N6) viruses, respectively. The six internal genes were homologous to avian influenza A (H5N2) viruses isolated in duck from Jiangxi in China. This H5N6 virus has not gained genetic mutations necessary for human infection and was suggested to be sensitive to neuraminidase inhibitors, but resistant to adamantanes. Epidemiological investigation of the exposure history of the patient found that a live poultry market could be the source place of infection and the incubation period was 2–5 days. This novel reassortant Avian influenza A(H5N6) virus could be low pathogenic in humans. The prevalence and genetic evolution of this virus should be closely monitored. PMID:26973295

  6. Clinical, epidemiological and virological characteristics of the first detected human case of avian influenza A(H5N6) virus.

    PubMed

    Zhang, Rusheng; Chen, Tianmu; Ou, Xinhua; Liu, Ruchun; Yang, Yang; Ye, Wen; Chen, Jingfang; Yao, Dong; Sun, Biancheng; Zhang, Xixing; Zhou, Jianxiang; Sun, Yan; Chen, Faming; Wang, Shi-Ping

    2016-06-01

    A human infection with novel avian influenza A H5N6 virus emerged in Changsha city, China in February, 2014. This is the first detected human case among all human cases identified from 2014 to early 2016. We obtained and summarized clinical, epidemiological, and virological data from this patient. Complete genome of the virus was determined and compared to other avian influenza viruses via the construction of phylogenetic trees using the neighbor-joining approach. A girl aged five and half years developed fever and mild respiratory symptoms on Feb. 16, 2014 and visited hospital on Feb. 17. Throat swab specimens were obtained from the patient and a novel reassortant avian influenza A H5N6 virus was detected. All eight viral gene segments were of avian origin. The hemagglutinin (HA) and neuraminidase (NA) gene segments were closely related to A/duck/Sichuan/NCXN11/2014(H5N1) and A/chicken/Jiangxi/12782/2014(H10N6) viruses, respectively. The six internal genes were homologous to avian influenza A (H5N2) viruses isolated in duck from Jiangxi in China. This H5N6 virus has not gained genetic mutations necessary for human infection and was suggested to be sensitive to neuraminidase inhibitors, but resistant to adamantanes. Epidemiological investigation of the exposure history of the patient found that a live poultry market could be the source place of infection and the incubation period was 2-5days. This novel reassortant Avian influenza A(H5N6) virus could be low pathogenic in humans. The prevalence and genetic evolution of this virus should be closely monitored.

  7. Analysis of human infectious avian influenza virus: hemagglutinin genetic characteristics in Asia and Africa from 2004 to 2009.

    PubMed

    Zhang, Jirong; Lei, Fumin

    2010-09-01

    In the present study, we used nucleotide and protein sequences of avian influenza virus H5N1, which were obtained in Asia and Africa, analyzed HA proteins using ClustalX1.83 and MEGA4.0, and built a genetic evolutionary tree of HA nucleotides. The analysis revealed that the receptor specificity amino acid of A/HK/213/2003, A/Turkey/65596/2006 and etc mutated into QNG, which could bind with á-2, 3 galactose and á-2, 6 galactose. A mutation might thus take place and lead to an outbreak of human infections of avian influenza virus. The mutations of HA protein amino acids from 2004 to 2009 coincided with human infections provided by the World Health Organization, indicating a "low-high-highest-high-low" pattern. We also found out that virus strains in Asia are from different origins: strains from Southeast Asia and East Asia are of the same origin, whereas those from West Asia, South Asia and Africa descend from one ancestor. The composition of the phylogenetic tree and mutations of key site amino acids in HA proteins reflected the fact that the majority of strains are regional and long term, and virus diffusions exist between China, Laos, Malaysia, Indonesia, Azerbaijan, Turkey and Iraq. We would advise that pertinent vaccines be developed and due attention be paid to the spread of viruses between neighboring countries and the dangers of virus mutation and evolution. PMID:21392344

  8. Estimating the Distribution of the Incubation Periods of Human Avian Influenza A(H7N9) Virus Infections.

    PubMed

    Virlogeux, Victor; Li, Ming; Tsang, Tim K; Feng, Luzhao; Fang, Vicky J; Jiang, Hui; Wu, Peng; Zheng, Jiandong; Lau, Eric H Y; Cao, Yu; Qin, Ying; Liao, Qiaohong; Yu, Hongjie; Cowling, Benjamin J

    2015-10-15

    A novel avian influenza virus, influenza A(H7N9), emerged in China in early 2013 and caused severe disease in humans, with infections occurring most frequently after recent exposure to live poultry. The distribution of A(H7N9) incubation periods is of interest to epidemiologists and public health officials, but estimation of the distribution is complicated by interval censoring of exposures. Imputation of the midpoint of intervals was used in some early studies, resulting in estimated mean incubation times of approximately 5 days. In this study, we estimated the incubation period distribution of human influenza A(H7N9) infections using exposure data available for 229 patients with laboratory-confirmed A(H7N9) infection from mainland China. A nonparametric model (Turnbull) and several parametric models accounting for the interval censoring in some exposures were fitted to the data. For the best-fitting parametric model (Weibull), the mean incubation period was 3.4 days (95% confidence interval: 3.0, 3.7) and the variance was 2.9 days; results were very similar for the nonparametric Turnbull estimate. Under the Weibull model, the 95th percentile of the incubation period distribution was 6.5 days (95% confidence interval: 5.9, 7.1). The midpoint approximation for interval-censored exposures led to overestimation of the mean incubation period. Public health observation of potentially exposed persons for 7 days after exposure would be appropriate.

  9. Novel Avian-Origin Influenza A (H7N9) Virus Attaches to Epithelium in Both Upper and Lower Respiratory Tract of Humans

    PubMed Central

    van Riel, Debby; Leijten, Lonneke M.E.; de Graaf, Miranda; Siegers, Jurre Y.; Short, Kirsty R.; Spronken, Monique I.J.; Schrauwen, Eefje J.A.; Fouchier, Ron A.M.; Osterhaus, Albert D.M.E.; Kuiken, Thijs

    2014-01-01

    Influenza A viruses from animal reservoirs have the capacity to adapt to humans and cause influenza pandemics. The occurrence of an influenza pandemic requires efficient virus transmission among humans, which is associated with virus attachment to the upper respiratory tract. Pandemic severity depends on virus ability to cause pneumonia, which is associated with virus attachment to the lower respiratory tract. Recently, a novel avian-origin H7N9 influenza A virus with unknown pandemic potential emerged in humans. We determined the pattern of attachment of two genetically engineered viruses containing the hemagglutinin of either influenza virus A/Shanghai/1/13 or A/Anhui/1/13 to formalin-fixed human respiratory tract tissues using histochemical analysis. Our results show that the emerging H7N9 virus attached moderately or abundantly to both upper and lower respiratory tract, a pattern not seen before for avian influenza A viruses. With the caveat that virus attachment is only the first step in the virus replication cycle, these results suggest that the emerging H7N9 virus has the potential both to transmit efficiently among humans and to cause severe pneumonia. PMID:24029490

  10. USGS highly pathogenic avian influenza research strategy

    USGS Publications Warehouse

    Harris, M. Camille; Miles, A. Keith; Pearce, John M.; Prosser, Diann J.; Sleeman, Jonathan M.; Whalen, Mary E.

    2015-09-09

    Avian influenza viruses are naturally occurring in wild birds such as ducks, geese, swans, and gulls. These viruses generally do not cause illness in wild birds, however, when spread to poultry they can be highly pathogenic and cause illness and death in backyard and commercial farms. Outbreaks may cause devastating agricultural economic losses and some viral strains have the potential to infect people directly. Furthermore, the combination of avian influenza viruses with mammalian viruses can result in strains with the ability to transmit from person to person, possibly leading to viruses with pandemic potential. All known pandemic influenza viruses have had some genetic material of avian origin. Since 1996, a strain of highly pathogenic avian influenza (HPAI) virus, H5N1, has caused infection in wild birds, losses to poultry farms in Eurasia and North Africa, and led to the deaths of several hundred people. Spread of the H5N1 virus and other influenza strains from China was likely facilitated by migratory birds. In December 2014, HPAI was detected in poultry in Canada and migratory birds in the United States. Since then, HPAI viruses have spread to large parts of the United States and will likely continue to spread through migratory bird flyways and other mechanisms throughout North America. In the United States, HPAI viruses have severely affected the poultry industry with millions of domestic birds dead or culled. These strains of HPAI are not known to cause disease in humans; however, the Centers for Disease Control and Prevention (CDC) advise caution when in close contact with infected birds. Experts agree that HPAI strains currently circulating in wild birds of North America will likely persist for the next few years. This unprecedented situation presents risks to the poultry industry, natural resource management, and potentially human health. Scientific knowledge and decision support tools are urgently needed to understand factors affecting the persistence

  11. USGS highly pathogenic avian influenza research strategy

    USGS Publications Warehouse

    Harris, M. Camille; Miles, A. Keith; Pearce, John M.; Prosser, Diann J.; Sleeman, Jonathan M.; Whalen, Mary E.

    2015-01-01

    Avian influenza viruses are naturally occurring in wild birds such as ducks, geese, swans, and gulls. These viruses generally do not cause illness in wild birds, however, when spread to poultry they can be highly pathogenic and cause illness and death in backyard and commercial farms. Outbreaks may cause devastating agricultural economic losses and some viral strains have the potential to infect people directly. Furthermore, the combination of avian influenza viruses with mammalian viruses can result in strains with the ability to transmit from person to person, possibly leading to viruses with pandemic potential. All known pandemic influenza viruses have had some genetic material of avian origin. Since 1996, a strain of highly pathogenic avian influenza (HPAI) virus, H5N1, has caused infection in wild birds, losses to poultry farms in Eurasia and North Africa, and led to the deaths of several hundred people. Spread of the H5N1 virus and other influenza strains from China was likely facilitated by migratory birds. In December 2014, HPAI was detected in poultry in Canada and migratory birds in the United States. Since then, HPAI viruses have spread to large parts of the United States and will likely continue to spread through migratory bird flyways and other mechanisms throughout North America. In the United States, HPAI viruses have severely affected the poultry industry with millions of domestic birds dead or culled. These strains of HPAI are not known to cause disease in humans; however, the Centers for Disease Control and Prevention (CDC) advise caution when in close contact with infected birds. Experts agree that HPAI strains currently circulating in wild birds of North America will likely persist for the next few years. This unprecedented situation presents risks to the poultry industry, natural resource management, and potentially human health. Scientific knowledge and decision support tools are urgently needed to understand factors affecting the persistence

  12. Mutations to PB2 and NP Proteins of an Avian Influenza Virus Combine To Confer Efficient Growth in Primary Human Respiratory Cells

    PubMed Central

    Danzy, Shamika; Studdard, Lydia R.; Manicassamy, Balaji; Solorzano, Alicia; Marshall, Nicolle; García-Sastre, Adolfo; Steel, John

    2014-01-01

    ABSTRACT Influenza pandemics occur when influenza A viruses (IAV) adapted to other host species enter humans and spread through the population. Pandemics are relatively rare due to host restriction of IAV: strains adapted to nonhuman species do not readily infect, replicate in, or transmit among humans. IAV can overcome host restriction through reassortment or adaptive evolution, and these are mechanisms by which pandemic strains arise in nature. To identify mutations that facilitate growth of avian IAV in humans, we have adapted influenza A/duck/Alberta/35/1976 (H1N1) (dk/AB/76) virus to a high-growth phenotype in differentiated human tracheo-bronchial epithelial (HTBE) cells. Following 10 serial passages of three independent lineages, the bulk populations showed similar growth in HTBE cells to that of a human seasonal virus. The coding changes present in six clonal isolates were determined. The majority of changes were located in the polymerase complex and nucleoprotein (NP), and all isolates carried mutations in the PB2 627 domain and regions of NP thought to interact with PB2. Using reverse genetics, the impact on growth and polymerase activity of individual and paired mutations in PB2 and NP was evaluated. The results indicate that coupling of the mammalian-adaptive mutation PB2 E627K or Q591K to selected mutations in NP further augments the growth of the corresponding viruses. In addition, minimal combinations of three (PB2 Q236H, E627K, and NP N309K) or two (PB2 Q591K and NP S50G) mutations were sufficient to recapitulate the efficient growth in HTBE cells of dk/AB/76 viruses isolated after 10 passages in this substrate. IMPORTANCE Influenza A viruses adapted to birds do not typically grow well in humans. However, as has been seen recently with H5N1 and H7N9 subtype viruses, productive and virulent infection of humans with avian influenza viruses can occur. The ability of avian influenza viruses to adapt to new host species is a consequence of their high

  13. Avian influenza: genetic evolution under vaccination pressure

    PubMed Central

    Escorcia, Magdalena; Vázquez, Lourdes; Méndez, Sara T; Rodríguez-Ropón, Andrea; Lucio, Eduardo; Nava, Gerardo M

    2008-01-01

    Antigenic drift of avian influenza viruses (AIVs) has been observed in chickens after extended vaccination program, similar to those observed with human influenza viruses. To evaluate the evolutionary properties of endemic AIV under high vaccination pressure (around 2 billion doses used in the last 12 years), we performed a pilot phylogenic analysis of the hemagglutinin (HA) gene of AIVs isolated from 1994 to 2006. This study demonstrates that Mexican low pathogenicity (LP) H5N2-AIVs are constantly undergoing genetic drifts. Recent AIV isolates (2002–2006) show significant molecular drifts when compared with the H5N2 vaccine-strain or other field isolates (1994–2000). This study also demonstrates that molecular drifts in the HA gene lineages follow a yearly trend, suggesting gradually cumulative sequence mutations. These findings might explain the increasing incidence of LP H5N2 AIV isolated from commercial avian farms. These findings support recent concerns about the challenge of AIV antigenic drift and influenza epidemics. PMID:18218105

  14. Avian influenza: an emerging pandemic threat.

    PubMed

    Jin, Xian Wen; Mossad, Sherif B

    2005-12-01

    While we are facing the threat of an emerging pandemic from the current avian flu outbreak in Asia, we have learned important traits of the virus responsible for the 1918 Spanish influenza pandemic that made it so deadly. By using stockpiled antiviral drugs effectively and developing an effective vaccine, we can be in a better position than ever to mitigate the global impact of an avian influenza pandemic. PMID:16392727

  15. Host Immune and Apoptotic Responses to Avian Influenza Virus H9N2 in Human Tracheobronchial Epithelial Cells

    PubMed Central

    Xing, Zheng; Harper, Richart; Anunciacion, Jerome; Yang, Zengqi; Gao, Wei; Qu, Bingqian; Guan, Yi; Cardona, Carol J.

    2011-01-01

    The avian influenza virus H9N2 subtype has circulated in wild birds, is prevalent in domestic poultry, and has successfully crossed the species boundary to infect humans. Phylogenetic analyses showed that viruses of this subtype appear to have contributed to the generation of highly pathogenic H5N1 viruses. Little is known about the host responses to H9N2 viruses in human airway respiratory epithelium, the primary portal for viral infection. Using an apically differentiated primary human tracheobronchial epithelial (TBE) culture, we examined host immune responses to infection by an avian H9N2 virus, in comparison with a human H9N2 isolate. We found that IFN-β was the prominent antiviral component, whereas interferon gamma-induced protein 10 kDa (IP-10), chemokine (C-C motif) ligand (CCL)-5 and TNF-α may be critical in proinflammatory responses to H9N2 viruses. In contrast, proinflammatory IL-1β, IL-8, and even IL-6 may only play a minor role in pathogenicity. Apparently Toll-like receptor (TLR)-3, TLR-7, and melanoma differentiation–associated gene 5 (MDA-5) contributed to the innate immunity against the H9N2 viruses, and MDA-5 was important in the induction of IFN-β. We showed that the avian H9N2 virus induced apoptosis through the mitochondria/cytochrome c–mediated intrinsic pathway, in addition to the caspase 8–mediated extrinsic pathway, as evidenced by the cytosolic presence of active caspase 9 and cytochrome c, independent of truncated BH3 interacting domain death agonist (Bid) activation. Further, we demonstrated that FLICE-like inhibitory protein (FLIP), an apoptotic dual regulator, and the p53-dependent Bcl-2 family members, Bax and Bcl-xs, appeared to be involved in the regulation of extrinsic and intrinsic apoptotic pathways, respectively. The findings in this study will further our understanding of host defense mechanisms and the pathogenesis of H9N2 influenza viruses in human respiratory epithelium. PMID:20118223

  16. Avian influenza: the political economy of disease control in Cambodia.

    PubMed

    Ear, Sophal

    2011-01-01

    Abstract In the wake of avian flu outbreaks in 2004, Cambodia received $45 million in commitments from international donors to help combat the spread of animal and human influenza, particularly avian influenza (H5N1). How countries leverage foreign aid to address the specific needs of donors and the endemic needs of the nation is a complex and nuanced issue throughout the developing world. Cambodia is a particularly compelling study in pandemic preparedness and the management of avian influenza because of its multilayered network of competing local, national, and global needs, and because the level of aid in Cambodia represents approximately $2.65 million per human case-a disproportionately high number when compared with neighbors Vietnam and Indonesia. This paper examines how the Cambodian government has made use of animal and human influenza funds to protect (or fail to protect) its citizens and the global community. It asks how effective donor and government responses were to combating avian influenza in Cambodia, and what improvements could be made at the local and international level to help prepare for and respond to future outbreaks. Based on original interviews, a field survey of policy stakeholders, and detailed examination of Cambodia's health infrastructure and policies, the findings illustrate that while pandemic preparedness has shown improvements since 2004, new outbreaks and human fatalities accelerated in 2011, and more work needs to be done to align the specific goals of funders with the endemic needs of developing nations.

  17. Planning and executing a vaccination campaign against avian influenza.

    PubMed

    Marangon, S; Cristalli, A; Busani, L

    2007-01-01

    Vaccination against avian influenza infection caused by H5 or H7 virus subtypes has been used on several occasions in recent years to control and in some cases eradicate the disease. In order to contain avian influenza infection effectively, immunization should be combined with a coordinated set of control and monitoring measures. The outcome of an immunization campaign depends on the territorial strategy; whereas the capacity of the veterinary services in developed countries permits enforcement of strategies aimed at eradicating avian influenza, many countries currently affected by highly pathogenic avian influenza (HPAI) H5N1 viruses have a limited veterinary infrastructure and a limited capacity to respond to such epidemics. In these countries, resources are still insufficient to conduct adequate surveillance for identification and reaction to avian influenza outbreaks when they occur. When properly applied in this scenario, immunization can reduce mortality and production losses. In the long term, immunization might also decrease the prevalence of infection to levels at which stamping-out and surveillance can be applied. Countries should adapt their immunization programmes to local conditions in order to guarantee their efficacy and sustainability. In the initial emergency phase, human resources can be mobilized, with reliance on personal responsibility and motivation, thus compensating for potential shortcomings in organization. A more appropriate allocation of resources must be pursued in the long term, remembering that biosecurity is the main component of an exit strategy and must always be improved.

  18. Structure and Receptor Binding Preferences of Recombinant Hemagglutinins from Avian and Human H6 and H10 Influenza A Virus Subtypes

    PubMed Central

    Yang, Hua; Carney, Paul J.; Chang, Jessie C.; Villanueva, Julie M.

    2015-01-01

    ABSTRACT During 2013, three new avian influenza A virus subtypes, A(H7N9), A(H6N1), and A(H10N8), resulted in human infections. While the A(H7N9) virus resulted in a significant epidemic in China across 19 provinces and municipalities, both A(H6N1) and A(H10N8) viruses resulted in only a few human infections. This study focuses on the major surface glycoprotein hemagglutinins from both of these novel human viruses. The detailed structural and glycan microarray analyses presented here highlight the idea that both A(H6N1) and A(H10N8) virus hemagglutinins retain a strong avian receptor binding preference and thus currently pose a low risk for sustained human infections. IMPORTANCE Human infections with zoonotic influenza virus subtypes continue to be a great public health concern. We report detailed structural analysis and glycan microarray data for recombinant hemagglutinins from A(H6N1) and A(H10N8) viruses, isolated from human infections in 2013, and compare them with hemagglutinins of avian origin. This is the first structural report of an H6 hemagglutinin, and our results should further the understanding of these viruses and provide useful information to aid in the continuous surveillance of these zoonotic influenza viruses. PMID:25673707

  19. Avian influenza viruses that cause highly virulent infections in humans exhibit distinct replicative properties in contrast to human H1N1 viruses

    PubMed Central

    Simon, Philippe F.; de La Vega, Marc-Antoine; Paradis, Éric; Mendoza, Emelissa; Coombs, Kevin M.; Kobasa, Darwyn; Beauchemin, Catherine A. A.

    2016-01-01

    Avian influenza viruses present an emerging epidemiological concern as some strains of H5N1 avian influenza can cause severe infections in humans with lethality rates of up to 60%. These have been in circulation since 1997 and recently a novel H7N9-subtyped virus has been causing epizootics in China with lethality rates around 20%. To better understand the replication kinetics of these viruses, we combined several extensive viral kinetics experiments with mathematical modelling of in vitro infections in human A549 cells. We extracted fundamental replication parameters revealing that, while both the H5N1 and H7N9 viruses replicate faster and to higher titers than two low-pathogenicity H1N1 strains, they accomplish this via different mechanisms. While the H7N9 virions exhibit a faster rate of infection, the H5N1 virions are produced at a higher rate. Of the two H1N1 strains studied, the 2009 pandemic H1N1 strain exhibits the longest eclipse phase, possibly indicative of a less effective neuraminidase activity, but causes infection more rapidly than the seasonal strain. This explains, in part, the pandemic strain’s generally slower growth kinetics and permissiveness to accept mutations causing neuraminidase inhibitor resistance without significant loss in fitness. Our results highlight differential growth properties of H1N1, H5N1 and H7N9 influenza viruses. PMID:27080193

  20. Avian influenza viruses that cause highly virulent infections in humans exhibit distinct replicative properties in contrast to human H1N1 viruses

    NASA Astrophysics Data System (ADS)

    Simon, Philippe F.; de La Vega, Marc-Antoine; Paradis, Éric; Mendoza, Emelissa; Coombs, Kevin M.; Kobasa, Darwyn; Beauchemin, Catherine A. A.

    2016-04-01

    Avian influenza viruses present an emerging epidemiological concern as some strains of H5N1 avian influenza can cause severe infections in humans with lethality rates of up to 60%. These have been in circulation since 1997 and recently a novel H7N9-subtyped virus has been causing epizootics in China with lethality rates around 20%. To better understand the replication kinetics of these viruses, we combined several extensive viral kinetics experiments with mathematical modelling of in vitro infections in human A549 cells. We extracted fundamental replication parameters revealing that, while both the H5N1 and H7N9 viruses replicate faster and to higher titers than two low-pathogenicity H1N1 strains, they accomplish this via different mechanisms. While the H7N9 virions exhibit a faster rate of infection, the H5N1 virions are produced at a higher rate. Of the two H1N1 strains studied, the 2009 pandemic H1N1 strain exhibits the longest eclipse phase, possibly indicative of a less effective neuraminidase activity, but causes infection more rapidly than the seasonal strain. This explains, in part, the pandemic strain’s generally slower growth kinetics and permissiveness to accept mutations causing neuraminidase inhibitor resistance without significant loss in fitness. Our results highlight differential growth properties of H1N1, H5N1 and H7N9 influenza viruses.

  1. Prevention and Treatment of Avian Influenza A Viruses in People

    MedlinePlus

    ... Research Making a Candidate Vaccine Virus Related Links Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... Button Past Newsletters Prevention and Treatment of Avian Influenza A Viruses in People Language: English Español ...

  2. Avian influenza surveillance of wild birds

    USGS Publications Warehouse

    Slota, Paul

    2007-01-01

    The President's National Strategy for Pandemic Influenza directs federal agencies to expand the surveillance of United States domestic livestock and wildlife to ensure early warning of hightly pathogenic avian influenza (HPAI) in the U.S. The immediate concern is a potential introduction of HPAI H5N1 virus into the U.S. The presidential directive resulted in the U.S. Interagency Strategic Plan for Early Detection of H5N1 Highly Pathogenic Avian Influenza in Wild Migratory Birds (referred to as the Wild Bird Surveillance Plan or the Plan).

  3. Different pH requirements are associated with divergent inhibitory effects of chloroquine on human and avian influenza A viruses

    PubMed Central

    Di Trani, Livia; Savarino, Andrea; Campitelli, Laura; Norelli, Sandro; Puzelli, Simona; D'Ostilio, Daniela; Vignolo, Edoardo; Donatelli, Isabella; Cassone, Antonio

    2007-01-01

    Chloroquine is a 4-aminoquinoline previously used in malaria therapy and now becoming an emerging investigational antiviral drug due to its broad spectrum of antiviral activities. To explore whether the low pH-dependency of influenza A viruses might affect the antiviral effects of chloroquine at clinically achievable concentrations, we tested the antiviral effects of this drug on selected human and avian viruses belonging to different subtypes and displaying different pH requirements. Results showed a correlation between the responses to chloroquine and NH4Cl, a lysosomotropic agent known to increase the pH of intracellular vesicles. Time-of-addition experiments showed that the inhibitory effect of chloroquine was maximal when the drug had been added at the time of infection and was lost after 2 h post-infection. This timing approximately corresponds to that of virus/cell fusion. Moreover, there was a clear correlation between the EC50 of chloroquine in vitro and the electrostatic potential of the HA subunit (HA2) mediating the virus/cell fusion process. Overall, the present study highlights the critical importance of a host cell factor such as intravesicular pH in determining the anti-influenza activity of chloroquine and other lysosomotropic agents. PMID:17477867

  4. 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

  5. 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

    2015-01-01

    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

  6. Reassortment between Avian H5N1 and Human Influenza Viruses Is Mainly Restricted to the Matrix and Neuraminidase Gene Segments

    PubMed Central

    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. PMID:23527283

  7. 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.

  8. DIVA vaccination strategies for avian influenza virus.

    PubMed

    Suarez, David L

    2012-12-01

    Vaccination for both low pathogenicity avian influenza and highly pathogenic avian influenza is commonly used by countries that have become endemic for avian influenza virus, but stamping-out policies are still common for countries with recently introduced disease. Stamping-out policies of euthanatizing infected and at-risk flocks has been an effective control tool, but it comes at a high social and economic cost. Efforts to identify alternative ways to respond to outbreaks without widespread stamping out has become a goal for organizations like the World Organisation for Animal Health. A major issue with vaccination for avian influenza is trade considerations because countries that vaccinate are often considered to be endemic for the disease and they typically lose their export markets. Primarily as a tool to promote trade, the concept of DIVA (differentiate infected from vaccinated animals) has been considered for avian influenza, but the goal for trade is to differentiate vaccinated and not-infected from vaccinated and infected animals because trading partners are unwilling to accept infected birds. Several different strategies have been investigated for a DIVA strategy, but each has advantages and disadvantages. A review of current knowledge on the research and implementation of the DIVA strategy will be discussed with possible ways to implement this strategy in the field. The increased desire for a workable DIVA strategy may lead to one of these ideas moving from the experimental to the practical.

  9. Avian Influenza: a global threat needing a global solution.

    PubMed

    Koh, Gch; Wong, Ty; Cheong, Sk; Koh, Dsq

    2008-11-13

    There have been three influenza pandemics since the 1900s, of which the 1919-1919 flu pandemic had the highest mortality rates. The influenza virus infects both humans and birds, and mutates using two mechanisms: antigenic drift and antigenic shift. Currently, the H5N1 avian flu virus is limited to outbreaks among poultry and persons in direct contact to infected poultry, but the mortality rate among infected humans is high. Avian influenza (AI) is endemic in Asia as a result of unregulated poultry rearing in rural areas. Such birds often live in close proximity to humans and this increases the chance of genetic re-assortment between avian and human influenza viruses which may produce a mutant strain that is easily transmitted between humans. Once this happens, a global pandemic is likely. Unlike SARS, a person with influenza infection is contagious before the onset of case-defining symptoms which limits the effectiveness of case isolation as a control strategy. Researchers have shown that carefully orchestrated of public health measures could potentially limit the spread of an AI pandemic if implemented soon after the first cases appear. To successfully contain and control an AI pandemic, both national and global strategies are needed. National strategies include source surveillance and control, adequate stockpiles of anti-viral agents, timely production of flu vaccines and healthcare system readiness. Global strategies such as early integrated response, curbing the disease outbreak at source, utilization of global resources, continuing research and open communication are also critical.

  10. 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

  11. 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

    2015-01-01

    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.

  12. Dose- and time-dependent apoptosis induced by avian H9N2 influenza virus in human cells.

    PubMed

    Shahsavandi, Shahla; Ebrahimi, Mohammad Majid; Sadeghi, Kaveh; Mosavi, Seyedeh Zahra; Mohammadi, Ashraf

    2013-01-01

    To understand human response to avian H9N2 influenza, we investigated the effects of the viral infection on A549, HepG2, and HeLa cells at low and high MOIs. To identify virus-host interplay, expression of Mx and NP genes was measured in the cells supernatants. Cell viability and apoptosis were evaluated by MTT assay, DNA fragmentation, and florescent staining. The virus titration and NP gene transcript levels indicate lower susceptibility of HeLa cell to H9N2 replication than other cells. Although H9N2 did produce a faster CPE in HepG2, high dose of the virus induced apoptosis within early stage of A549 infection. The DNA laddering was enhanced in the cell correlated with increase in virus transcripts. The undetectable to different regulation levels of Mx gene were observed in response to H9N2 infection suggesting that an insufficient antiviral defense in the noncompetent-IFN HepG2 cell promotes efficient viral replication. These results showed that the permissivity of HepG2 for H9N2 is comparable with A549; however, liver cells are not target tissue respond to the infection. These data revealed that the H9N2 virus induced apoptosis signaling via mitochondrial pathway in human alveolar epithelial cells, indicating that the induction may be associated with a dose-dependent manner.

  13. 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

    2015-01-01

    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

  14. A brief introduction to avian influenza virus.

    PubMed

    Spackman, Erica

    2014-01-01

    Avian influenza virus (AIV) causes a disease of high economic importance for poultry production worldwide. The earliest recorded cases of probable high-pathogenicity AIV in poultry were reported in Italy in the 1870s, and avian influenza has been recognized in domestic poultry through the modern era of poultry production. Approaches to control vary widely, but elimination of the disease in poultry is a common goal. The basics of AIV biology, clinical disease, molecular aspects, and AIV detection are briefly reviewed. PMID:24899420

  15. Avian Influenza A Viruses: Evolution and Zoonotic Infection.

    PubMed

    Kim, Se Mi; Kim, Young-Il; Pascua, Philippe Noriel Q; Choi, Young Ki

    2016-08-01

    Although efficient human-to-human transmission of avian influenza virus has yet to be seen, in the past two decades avian-to-human transmission of influenza A viruses has been reported. Influenza A/H5N1, in particular, has repeatedly caused human infections associated with high mortality, and since 1998 the virus has evolved into many clades of variants with significant antigenic diversity. In 2013, three (A/H7N9, A/H6N1, and A/H10N8) novel avian influenza viruses (AIVs) breached the animal-human host species barrier in Asia. In humans, roughly 35% of A/H7N9-infected patients succumbed to the zoonotic infection, and two of three A/H10N8 human infections were also lethal; however, neither of these viruses cause influenza-like symptoms in poultry. While most of these cases were associated with direct contact with infected poultry, some involved sustained human-to-human transmission. Thus, these events elicited concern regarding potential AIV pandemics. This article reviews the human incursions associated with AIV variants and the potential role of pigs as an intermediate host that may hasten AIV evolution. In addition, we discuss the known influenza A virus virulence and transmission factors and their evaluation in animal models. With the growing number of human AIV infections, constant vigilance for the emergence of novel viruses is of utmost importance. In addition, careful characterization and pathobiological assessment of these novel variants will help to identify strains of particular concern for future pandemics. PMID:27486732

  16. Animal and human influenzas.

    PubMed

    Peiris, M; Yen, H-L

    2014-08-01

    Influenza type A viruses affect humans and other animals and cause significant morbidity, mortality and economic impact. Influenza A viruses are well adapted to cross species barriers and evade host immunity. Viruses that cause no clinical signs in wild aquatic birds may adapt in domestic poultry to become highly pathogenic avian influenza viruses which decimate poultry flocks. Viruses that cause asymptomatic infection in poultry (e.g. the recently emerged A/H7N9 virus) may cause severe zoonotic disease and pose a major pandemic threat. Pandemic influenza arises at unpredictable intervals from animal viruses and, in its global spread, outpaces current technologies for making vaccines against such novel viruses. Confronting the threat of influenza in humans and other animals is an excellent example of a task that requires a One Health approach. Changes in travel, trade in livestock and pets, changes in animal husbandry practices, wet markets and complex marketing chains all contribute to an increased risk of the emergence of novel influenza viruses with the ability to cross species barriers, leading to epizootics or pandemics. Coordinated surveillance at the animal- human interface for pandemic preparedness, risk assessment, risk reduction and prevention at source requires coordinated action among practitioners in human and animal health and the environmental sciences. Implementation of One Health in the field can be challenging because of divergent short-term objectives. Successful implementation requires effort, mutual trust, respect and understanding to ensure that long-term goals are achieved without adverse impacts on agricultural production and food security.

  17. Troop education and avian influenza surveillance in military barracks in Ghana, 2011

    PubMed Central

    2012-01-01

    Background Influenza A viruses that cause highly pathogenic avian influenza (HPAI) also infect humans. In many developing countries such as Ghana, poultry and humans live in close proximity in both the general and military populations, increasing risk for the spread of HPAI from birds to humans. Respiratory infections such as influenza are especially prone to rapid spread among military populations living in close quarters such as barracks making this a key population for targeted avian influenza surveillance and public health education. Method Twelve military barracks situated in the coastal, tropical rain forest and northern savannah belts of the country were visited and the troops and their families educated on pandemic avian influenza. Attendants at each site was obtained from the attendance sheet provided for registration. The seminars focused on zoonotic diseases, influenza surveillance, pathogenesis of avian influenza, prevention of emerging infections and biosecurity. To help direct public health policies, a questionnaire was used to collect information on animal populations and handling practices from 102 households in the military barracks. Cloacal and tracheal samples were taken from 680 domestic and domesticated wild birds and analysed for influenza A using molecular methods for virus detection. Results Of the 1028 participants that took part in the seminars, 668 (65%) showed good knowledge of pandemic avian influenza and the risks associated with its infection. Even though no evidence of the presence of avian influenza (AI) infection was found in the 680 domestic and wild birds sampled, biosecurity in the households surveyed was very poor. Conclusion Active surveillance revealed that there was no AI circulation in the military barracks in April 2011. Though participants demonstrated good knowledge of pandemic avian influenza, biosecurity practices were minimal. Sustained educational programs are needed to further strengthen avian influenza surveillance

  18. Emergence of avian H1N1 influenza viruses in pigs in China.

    PubMed

    Guan, Y; Shortridge, K F; Krauss, S; Li, P H; Kawaoka, Y; Webster, R G

    1996-11-01

    Avian influenza A viruses from Asia are recognized as the source of genes that reassorted with human viral genes to generate the Asian/57 (H2N2) and Hong Kong/68 (H3N2) pandemic strains earlier in this century. Here we report the genetic analysis of avian influenza A H1N1 viruses recently isolated from pigs in southern China, a host suspected to generate new pandemic strains through gene reassortment events. Each of the eight gene segments was of avian origin. Phylogenetic analysis indicates that these genes form an Asian sublineage of the Eurasian avian lineage, suggesting that these viruses are an independent introduction into pigs in Asia. The presence of avian influenza viruses in pigs in China places them in an optimal position for transmission to humans and may serve as an early warning of the emergence of the next human influenza virus pandemic.

  19. Avian influenza virus and Newcastle disease virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) and Newcastle disease virus (NDV) severely impact poultry egg production. Decreased egg yield and hatchability, as well as misshapen eggs, are often observed during infection with AIV and NDV, even with low-virulence strains or in vaccinated flocks. Data suggest that in...

  20. The global nature of avian influenza

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) virus (AIV) is a global virus which knows no geographic boundaries, has no political agenda, and can infect poultry irrespective of their occupying ecosystem, agricultural production system, or other anthropocentric niches. AIVs or evidence of their infection have been detected...

  1. 77 FR 34783 - Highly Pathogenic Avian Influenza

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-12

    ... avian influenza (HPAI). On January 24, 2011, we published in the Federal Register (76 FR 4046-4056... Register on May 3, 2011 (76 FR 24793, Docket No. APHIS-2006-0074), we reopened the comment period for an... publication of the interim rule establishing that pigeons (and other Columbiform species such as doves) have...

  2. Pathobiology of avian influenza in domestic ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domestic ducks are an important source of food and income in many parts of the world. The susceptibility of domestic ducks to avian influenza (AI) viruses varies depending on many factors, including the species and the age of the ducks, the virus strain, and management practices. Although wild wat...

  3. Active surveillance for avian influenza virus, Egypt, 2010-2012.

    PubMed

    Kayali, Ghazi; Kandeil, Ahmed; El-Shesheny, Rabeh; Kayed, Ahmed S; Gomaa, Mokhtar M; Maatouq, Asmaa M; Shehata, Mahmoud M; Moatasim, Yassmin; Bagato, Ola; Cai, Zhipeng; Rubrum, Adam; Kutkat, Mohamed A; McKenzie, Pamela P; Webster, Robert G; Webby, Richard J; Ali, Mohamed A

    2014-04-01

    Continuous circulation of influenza A(H5N1) virus among poultry in Egypt has created an epicenter in which the viruses evolve into newer subclades and continue to cause disease in humans. To detect influenza viruses in Egypt, since 2009 we have actively surveyed various regions and poultry production sectors. From August 2010 through January 2013, >11,000 swab samples were collected; 10% were positive by matrix gene reverse transcription PCR. During this period, subtype H9N2 viruses emerged, cocirculated with subtype H5N1 viruses, and frequently co-infected the same avian host. Genetic and antigenic analyses of viruses revealed that influenza A(H5N1) clade 2.2.1 viruses are dominant and that all subtype H9N2 viruses are G1-like. Cocirculation of different subtypes poses concern for potential reassortment. Avian influenza continues to threaten public and animal health in Egypt, and continuous surveillance for avian influenza virus is needed.

  4. A human antibody recognizing a conserved epitope of H5 hemagglutinin broadly neutralizes highly pathogenic avian influenza H5N1 viruses.

    PubMed

    Hu, Hongxing; Voss, Jarrod; Zhang, Guoliang; Buchy, Philippi; Zuo, Teng; Wang, Lulan; Wang, Feng; Zhou, Fan; Wang, Guiqing; Tsai, Cheguo; Calder, Lesley; Gamblin, Steve J; Zhang, Linqi; Deubel, Vincent; Zhou, Boping; Skehel, John J; Zhou, Paul

    2012-03-01

    Influenza A virus infection is a persistent threat to public health worldwide due to its ability to evade immune surveillance through rapid genetic drift and shift. Current vaccines against influenza A virus provide immunity to viral isolates that are similar to vaccine strains. High-affinity neutralizing antibodies against conserved epitopes could provide immunity to diverse influenza virus strains and protection against future pandemic viruses. In this study, by using a highly sensitive H5N1 pseudotype-based neutralization assay to screen human monoclonal antibodies produced by memory B cells from an H5N1-infected individual and molecular cloning techniques, we developed three fully human monoclonal antibodies. Among them, antibody 65C6 exhibited potent neutralization activity against all H5 clades and subclades except for subclade 7.2 and prophylactic and therapeutic efficacy against highly pathogenic avian influenza H5N1 viruses in mice. Studies on hemagglutinin (HA)-antibody complexes by electron microscopy and epitope mapping indicate that antibody 65C6 binds to a conformational epitope comprising amino acid residues at positions 118, 121, 161, 164, and 167 (according to mature H5 numbering) on the tip of the membrane-distal globular domain of HA. Thus, we conclude that antibody 65C6 recognizes a neutralization epitope in the globular head of HA that is conserved among almost all divergent H5N1 influenza stains. PMID:22238297

  5. Early apoptosis of porcine alveolar macrophages limits avian influenza virus replication and pro-inflammatory dysregulation.

    PubMed

    Chang, Pengxiang; Kuchipudi, Suresh V; Mellits, Kenneth H; Sebastian, Sujith; James, Joe; Liu, Jinhua; Shelton, Holly; Chang, Kin-Chow

    2015-01-01

    Pigs are evidently more resistant to avian than swine influenza A viruses, mediated in part through frontline epithelial cells and alveolar macrophages (AM). Although porcine AM (PAM) are crucial in influenza virus control, their mode of control is unclear. To gain insight into the possible role of PAM in the mediation of avian influenza virus resistance, we compared the host effects and replication of two avian (H2N3 and H6N1) and three mammalian (swine H1N1, human H1N1 and pandemic H1N1) influenza viruses in PAM. We found that PAM were readily susceptible to initial infection with all five avian and mammalian influenza viruses but only avian viruses caused early and extensive apoptosis (by 6 h of infection) resulting in reduced virus progeny and moderated pro-inflammation. Full length viral PB1-F2 present only in avian influenza viruses is a virulence factor that targets AM for mitochondrial-associated apoptotic cell death. With the use of reverse genetics on an avian H5N1 virus, we found that full length PB1-F2 contributed to increased apoptosis and pro-inflammation but not to reduced virus replication. Taken together, we propose that early apoptosis of PAM limits the spread of avian influenza viruses and that PB1-F2 could play a contributory role in the process. PMID:26642934

  6. Early apoptosis of porcine alveolar macrophages limits avian influenza virus replication and pro-inflammatory dysregulation

    PubMed Central

    Chang, Pengxiang; Kuchipudi, Suresh V.; Mellits, Kenneth H.; Sebastian, Sujith; James, Joe; Liu, Jinhua; Shelton, Holly; Chang, Kin-Chow

    2015-01-01

    Pigs are evidently more resistant to avian than swine influenza A viruses, mediated in part through frontline epithelial cells and alveolar macrophages (AM). Although porcine AM (PAM) are crucial in influenza virus control, their mode of control is unclear. To gain insight into the possible role of PAM in the mediation of avian influenza virus resistance, we compared the host effects and replication of two avian (H2N3 and H6N1) and three mammalian (swine H1N1, human H1N1 and pandemic H1N1) influenza viruses in PAM. We found that PAM were readily susceptible to initial infection with all five avian and mammalian influenza viruses but only avian viruses caused early and extensive apoptosis (by 6 h of infection) resulting in reduced virus progeny and moderated pro-inflammation. Full length viral PB1-F2 present only in avian influenza viruses is a virulence factor that targets AM for mitochondrial-associated apoptotic cell death. With the use of reverse genetics on an avian H5N1 virus, we found that full length PB1-F2 contributed to increased apoptosis and pro-inflammation but not to reduced virus replication. Taken together, we propose that early apoptosis of PAM limits the spread of avian influenza viruses and that PB1-F2 could play a contributory role in the process. PMID:26642934

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

    PubMed

    Skeik, Nedaa; Jabr, Fadi I

    2008-05-01

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

  8. Avian influenza in shorebirds: experimental infection of ruddy turnstones (Arenaria interpres) with avian influenza virus

    USGS Publications Warehouse

    Hall, Jeffrey S.; Krauss, Scott; Franson, J. Christian; TeSlaa, Joshua L.; Nashold, Sean W.; Stallknecht, David E.; Webby, Richard J.; Webster, Robert G.

    2013-01-01

    Background: Low pathogenic avian influenza viruses (LPAIV) have been reported in shorebirds, especially at Delaware Bay, USA, during spring migration. However, data on patterns of virus excretion, minimal infectious doses, and clinical outcome are lacking. The ruddy turnstone (Arenaria interpres) is the shorebird species with the highest prevalence of influenza virus at Delaware Bay. Objectives: The primary objective of this study was to experimentally assess the patterns of influenza virus excretion, minimal infectious doses, and clinical outcome in ruddy turnstones. Methods: We experimentally challenged ruddy turnstones using a common LPAIV shorebird isolate, an LPAIV waterfowl isolate, or a highly pathogenic H5N1 avian influenza virus. Cloacal and oral swabs and sera were analyzed from each bird. Results: Most ruddy turnstones had pre-existing antibodies to avian influenza virus, and many were infected at the time of capture. The infectious doses for each challenge virus were similar (103·6–104·16 EID50), regardless of exposure history. All infected birds excreted similar amounts of virus and showed no clinical signs of disease or mortality. Influenza A-specific antibodies remained detectable for at least 2 months after inoculation. Conclusions: These results provide a reference for interpretation of surveillance data, modeling, and predicting the risks of avian influenza transmission and movement in these important hosts.

  9. The scientific rationale for the World Organisation for Animal Health standards and recommendations on avian influenza.

    PubMed

    Pasick, J; Kahn, S

    2014-12-01

    The World Organisation for Animal Health (OIE) prescribes standards for the diagnosis and control of avian influenza, as well as health measures for safe trade in birds and avian products, which are based on up-to-date scientific information and risk management principles, consistent with the role of the OIE as a reference standard-setting body for the World Trade Organization (WTO). These standards and recommendations continue to evolve, reflecting advances in technology and scientific understanding of this important zoonotic disease. The avian influenza viruses form part of the natural ecosystem by virtue of their ubiquitous presence in wild aquatic birds, a fact that human intervention cannot change. For the purposes of the Terrestrial Animal Health Code (Terrestrial Code), avian influenza is defined as an infection of poultry. However, the scope of the OIE standards and recommendations is not restricted to poultry, covering the diagnosis, early detection and management of avian influenza, including sanitary measures for trade in birds and avian products. The best way to manage avian influenza-associated risks to human and animal health is for countries to conduct surveillance using recommended methods, to report results in a consistent and transparent manner, and to applythe sanitary measures described in the Terrestrial Code. Surveillance for and timely reporting of avian influenza in accordance with OIE standards enable the distribution of relevant, up-to-date information to the global community.

  10. High titer growth of human and avian influenza viruses in an immortalized chick embryo cell line without the need for exogenous proteases.

    PubMed

    Smith, Kristen A; Colvin, Christopher J; Weber, Patty S D; Spatz, Stephen J; Coussens, Paul M

    2008-07-01

    The current method of growing influenza virus for vaccine production is through the use of embryonated chicken eggs. This manufacturing system yields a low concentration of virus per egg, requires significant downstream production for purification, and demands a considerable amount of time for production. We have demonstrated an immortalized chick embryo cell line, termed PBS-1, is capable of growing unmodified recent isolates of human and avian influenza A and B viruses to extremely high titers. In many cases, PBS-1 cells out perform primary chick embryo kidney (CEK) cells, Madin-Darby Canine Kidney (MDCK) cells and African green monkey kidney cells (Vero) in growth of recent influenza isolates. PBS-1 cells are free of any exogenous agents, are non-tumorigenic, and are readily adaptable to a variety of culture conditions, including growth on microcarrier beads. Influenza viruses grown in PBS-1 cells are released into the culture fluid without the need for exogenous proteases, thus simplifying downstream processing. In addition to offering a significant improvement in vaccine production, PBS-1 cells should prove valuable in diagnostics and as a cell line of choice for influenza virus research.

  11. Avian influenza: potential impact on sub-Saharan military populations with high rates of human immunodeficiency virus/acquired immunodeficiency syndrome.

    PubMed

    Feldman, Robert L; Nickell, Kent

    2007-07-01

    Several sub-Saharan militaries have large percentages of troops with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome. With the arrival of avian influenza in Africa, the potential exists that some of those soldiers might also become infected with H5N1, the virus responsible for the disease. Two possible scenarios have been postulated regarding how such a coinfection of HIV and H5N1 might present. (1) Soldiers already weakened by HIV/acquired immunodeficiency syndrome rapidly succumb to H5N1. The cause of death is a "cytokine storm," essentially a runaway inflammatory response. (2) The weakened immune system prevents the cytokine storm from occurring; however, H5N1 is still present, replicating, and being shed, leading to the infection of others. A cytokine storm is particularly dangerous for individuals of military age, as evidenced by the large number of soldiers who died during the 1918 influenza epidemic. If large numbers of sub-Saharan soldiers suffer a similar fate from avian influenza, then military and political instability could develop.

  12. Human Antibody Responses to Avian Influenza A(H7N9) Virus, 2013

    PubMed Central

    Guo, Li; Zhang, Xi; Ren, Lili; Yu, Xuelian; Chen, Lijuan; Zhou, Hongli; Gao, Xin; Teng, Zheng; Li, Jianguo; Hu, Jiayu; Wu, Chao; Xiao, Xia; Zhu, Yiyi; Wang, Quanyi; Pang, Xinghuo; Jin, Qi; Wu, Fan

    2014-01-01

    Understanding host antibody response is crucial for predicting disease severity and for vaccine development. We investigated antibody responses against influenza A(H7N9) virus in 48 serum samples from 21 patients, including paired samples from 15 patients. IgG against subtype H7 and neutralizing antibodies (NAbs) were not detected in acute-phase samples, but ELISA geometric mean titers increased in convalescent-phase samples; NAb titers were 20–80 (geometric mean titer 40). Avidity to IgG against subtype H7 was significantly lower than that against H1 and H3. IgG against H3 was boosted after infection with influenza A(H7N9) virus, and its level in acute-phase samples correlated with that against H7 in convalescent-phase samples. A correlation was also found between hemagglutinin inhibition and NAb titers and between hemagglutinin inhibition and IgG titers against H7. Because of the relatively weak protective antibody response to influenza A(H7N9), multiple vaccinations might be needed to achieve protective immunity. PMID:24447423

  13. Avian influenza virus and free-ranging wild birds

    USGS Publications Warehouse

    Dierauf, Leslie A.; Karesh, W.B.; Ip, Hon S.; Gilardi, K.V.; Fischer, John R.

    2006-01-01

    Recent media and news reports and other information implicate wild birds in the spread of highly pathogenic avian influenza in Asia and Eastern Europe. Although there is little information concerning highly pathogenic avian influenza viruses in wild birds, scientists have amassed a large amount of data on low-pathogenicity avian influenza viruses during decades of research with wild birds. This knowledge can provide sound guidance to veterinarians, public health professionals, the general public, government agencies, and other entities with concerns about avian influenza.

  14. Mycophenolic acid, an immunomodulator, has potent and broad-spectrum in vitro antiviral activity against pandemic, seasonal and avian influenza viruses affecting humans.

    PubMed

    To, Kelvin K W; Mok, Ka-Yi; Chan, Andy S F; Cheung, Nam N; Wang, Pui; Lui, Yin-Ming; Chan, Jasper F W; Chen, Honglin; Chan, Kwok-Hung; Kao, Richard Y T; Yuen, Kwok-Yung

    2016-08-01

    Immunomodulators have been shown to improve the outcome of severe pneumonia. We have previously shown that mycophenolic acid (MPA), an immunomodulator, has antiviral activity against influenza A/WSN/1933(H1N1) using a high-throughput chemical screening assay. This study further investigated the antiviral activity and mechanism of action of MPA against contemporary clinical isolates of influenza A and B viruses. The 50 % cellular cytotoxicity (CC50) of MPA in Madin Darby canine kidney cell line was over 50 µM. MPA prevented influenza virus-induced cell death in the cell-protection assay, with significantly lower IC50 for influenza B virus B/411 than that of influenza A(H1N1)pdm09 virus H1/415 (0.208 vs 1.510 µM, P=0.0001). For H1/415, MPA interfered with the early stage of viral replication before protein synthesis. For B/411, MPA may also act at a later stage since MPA was active against B/411 even when added 12 h post-infection. Virus-yield reduction assay showed that the replication of B/411 was completely inhibited by MPA at concentrations ≥0.78 µM, while there was a dose-dependent reduction of viral titer for H1/415. The antiviral effect of MPA was completely reverted by guanosine supplementation. Plaque reduction assay showed that MPA had antiviral activity against eight different clinical isolates of A(H1N1), A(H3N2), A(H7N9) and influenza B viruses (IC50 <1 µM). In summary, MPA has broad-spectrum antiviral activity against human and avian-origin influenza viruses, in addition to its immunomodulatory activity. Together with a high chemotherapeutic index, the use of MPA as an antiviral agent should be further investigated in vivo. PMID:27259985

  15. Mycophenolic acid, an immunomodulator, has potent and broad-spectrum in vitro antiviral activity against pandemic, seasonal and avian influenza viruses affecting humans.

    PubMed

    To, Kelvin K W; Mok, Ka-Yi; Chan, Andy S F; Cheung, Nam N; Wang, Pui; Lui, Yin-Ming; Chan, Jasper F W; Chen, Honglin; Chan, Kwok-Hung; Kao, Richard Y T; Yuen, Kwok-Yung

    2016-08-01

    Immunomodulators have been shown to improve the outcome of severe pneumonia. We have previously shown that mycophenolic acid (MPA), an immunomodulator, has antiviral activity against influenza A/WSN/1933(H1N1) using a high-throughput chemical screening assay. This study further investigated the antiviral activity and mechanism of action of MPA against contemporary clinical isolates of influenza A and B viruses. The 50 % cellular cytotoxicity (CC50) of MPA in Madin Darby canine kidney cell line was over 50 µM. MPA prevented influenza virus-induced cell death in the cell-protection assay, with significantly lower IC50 for influenza B virus B/411 than that of influenza A(H1N1)pdm09 virus H1/415 (0.208 vs 1.510 µM, P=0.0001). For H1/415, MPA interfered with the early stage of viral replication before protein synthesis. For B/411, MPA may also act at a later stage since MPA was active against B/411 even when added 12 h post-infection. Virus-yield reduction assay showed that the replication of B/411 was completely inhibited by MPA at concentrations ≥0.78 µM, while there was a dose-dependent reduction of viral titer for H1/415. The antiviral effect of MPA was completely reverted by guanosine supplementation. Plaque reduction assay showed that MPA had antiviral activity against eight different clinical isolates of A(H1N1), A(H3N2), A(H7N9) and influenza B viruses (IC50 <1 µM). In summary, MPA has broad-spectrum antiviral activity against human and avian-origin influenza viruses, in addition to its immunomodulatory activity. Together with a high chemotherapeutic index, the use of MPA as an antiviral agent should be further investigated in vivo.

  16. 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

  17. 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.

  18. Lack of transmission of a human influenza virus with avian receptor specificity between ferrets is not due to decreased virus shedding but rather a lower infectivity in vivo.

    PubMed

    Roberts, Kim L; Shelton, Holly; Scull, Margaret; Pickles, Raymond; Barclay, Wendy S

    2011-08-01

    Influenza virus attaches to host cells by sialic acid (SA). Human influenza viruses show preferential affinity for α2,6-linked SA, whereas avian influenza viruses bind α2,3-linked SA. In this study, mutation of the haemagglutinin receptor-binding site of a human H3N2 influenza A virus to switch binding to α2,3-linked SA did not eliminate infection of ferrets but prevented transmission, even in a co-housed model. The mutant virus was shed from the noses of ferrets directly inoculated with virus in the same amounts and for the same length of time as wild-type virus. Mutant virus infection was localized to the same anatomical regions of the upper respiratory tract of directly inoculated animals. Interestingly, wild-type virus was more readily neutralized than the mutant virus in vitro by ferret nasal washes containing mucus. Moreover after inoculation of equal doses, the mutant virus grew poorly in ex vivo ferret nasal turbinate tissue compared with wild-type virus. The dose of mutant virus required to establish infection in the directly inoculated ferrets was 40-fold higher than for wild-type virus. It was concluded that minimum infectious dose is a predictor of virus transmissibility and it is suggested that, as virus passes from one host to another through stringent environmental conditions, viruses with a preference for α2,3-linked SA are unlikely to inoculate a new mammalian host in sufficient quantities to initiate a productive infection.

  19. Detection of Evolutionarily Distinct Avian Influenza A Viruses in Antarctica

    PubMed Central

    Vijaykrishna, Dhanasekaran; Butler, Jeffrey; Baas, Chantal; Maurer-Stroh, Sebastian; Silva-de-la-Fuente, M. Carolina; Medina-Vogel, Gonzalo; Olsen, Bjorn; Kelso, Anne; Barr, Ian G.; González-Acuña, Daniel

    2014-01-01

    ABSTRACT Distinct lineages of avian influenza viruses (AIVs) are harbored by spatially segregated birds, yet significant surveillance gaps exist around the globe. Virtually nothing is known from the Antarctic. Using virus culture, molecular analysis, full genome sequencing, and serology of samples from Adélie penguins in Antarctica, we confirmed infection by H11N2 subtype AIVs. Their genetic segments were distinct from all known contemporary influenza viruses, including South American AIVs, suggesting spatial separation from other lineages. Only in the matrix and polymerase acidic gene phylogenies did the Antarctic sequences form a sister relationship to South American AIVs, whereas distant phylogenetic relationships were evident in all other gene segments. Interestingly, their neuraminidase genes formed a distant relationship to all avian and human influenza lineages, and the polymerase basic 1 and polymerase acidic formed a sister relationship to the equine H3N8 influenza virus lineage that emerged during 1963 and whose avian origins were previously unknown. We also estimated that each gene segment had diverged for 49 to 80 years from its most closely related sequences, highlighting a significant gap in our AIV knowledge in the region. We also show that the receptor binding properties of the H11N2 viruses are predominantly avian and that they were unable to replicate efficiently in experimentally inoculated ferrets, suggesting their continuous evolution in avian hosts. These findings add substantially to our understanding of both the ecology and the intra- and intercontinental movement of Antarctic AIVs and highlight the potential risk of an incursion of highly pathogenic AIVs into this fragile environment. PMID:24803521

  20. Assessment of Human Immune Responses to H7 Avian Influenza Virus of Pandemic Potential: Results from a Placebo–Controlled, Randomized Double–Blind Phase I Study of Live Attenuated H7N3 Influenza Vaccine

    PubMed Central

    Rudenko, Larisa; Kiseleva, Irina; Naykhin, Anatoly N.; Erofeeva, Marianna; Stukova, Marina; Donina, Svetlana; Petukhova, Galina; Pisareva, Maria; Krivitskaya, Vera; Grudinin, Michael; Buzitskaya, Zhanna; Isakova–Sivak, Irina; Kuznetsova, Svetlana; Larionova, Natalie; Desheva, Julia; Dubrovina, Irina; Nikiforova, Alexandra; Victor, John C.; Neuzil, Kathy; Flores, Jorge; Tsvetnitsky, Vadim; Kiselev, Oleg

    2014-01-01

    Introduction Live attenuated influenza vaccines (LAIVs) are being developed to protect humans against future epidemics and pandemics. This study describes the results of a double–blinded randomized placebo–controlled phase I clinical trial of cold–adapted and temperature sensitive H7N3 live attenuated influenza vaccine candidate in healthy seronegative adults. Objective The goal of the study was to evaluate the safety, tolerability, immunogenicity and potential shedding and transmission of H7N3 LAIV against H7 avian influenza virus of pandemic potential. Methods and Findings Two doses of H7N3 LAIV or placebo were administered to 40 randomly divided subjects (30 received vaccine and 10 placebo). The presence of influenza A virus RNA in nasal swabs was detected in 60.0% and 51.7% of subjects after the first and second vaccination, respectively. In addition, vaccine virus was not detected among placebo recipients demonstrating the absence of person–to–person transmission. The H7N3 live attenuated influenza vaccine demonstrated a good safety profile and was well tolerated. The two–dose immunization resulted in measurable serum and local antibody production and in generation of antigen–specific CD4+ and CD8+ memory T cells. Composite analysis of the immune response which included hemagglutinin inhibition assay, microneutralization tests, and measures of IgG and IgA and virus–specific T cells showed that the majority (86.2%) of vaccine recipients developed serum and/or local antibodies responses and generated CD4+ and CD8+ memory T cells. Conclusions The H7N3 LAIV was safe and well tolerated, immunogenic in healthy seronegative adults and elicited production of antibodies broadly reactive against the newly emerged H7N9 avian influenza virus. Trial registration ClinicalTrials.gov NCT01511419 PMID:24533064

  1. Quantification of bird-to-bird and bird-to-human infections during 2013 novel H7N9 avian influenza outbreak in China.

    PubMed

    Hsieh, Ying-Hen; Wu, Jianhong; Fang, Jian; Yang, Yong; Lou, Jie

    2014-01-01

    From February to May, 2013, 132 human avian influenza H7N9 cases were identified in China resulting in 37 deaths. We developed a novel, simple and effective compartmental modeling framework for transmissions among (wild and domestic) birds as well as from birds to human, to infer important epidemiological quantifiers, such as basic reproduction number for bird epidemic, bird-to-human infection rate and turning points of the epidemics, for the epidemic via human H7N9 case onset data and to acquire useful information regarding the bird-to-human transmission dynamics. Estimated basic reproduction number for infections among birds is 4.10 and the mean daily number of human infections per infected bird is 3.16*10-5 [3.08*10-5, 3.23*10-5]. The turning point of 2013 H7N9 epidemic is pinpointed at April 16 for bird infections and at April 9 for bird-to-human transmissions. Our result reveals very low level of bird-to-human infections, thus indicating minimal risk of widespread bird-to-human infections of H7N9 virus during the outbreak. Moreover, the turning point of the human epidemic, pinpointed at shortly after the implementation of full-scale control and intervention measures initiated in early April, further highlights the impact of timely actions on ending the outbreak. This is the first study where both the bird and human components of an avian influenza epidemic can be quantified using only the human case data.

  2. A mathematical model of avian influenza with half-saturated incidence.

    PubMed

    Chong, Nyuk Sian; Tchuenche, Jean Michel; Smith, Robert J

    2014-03-01

    The widespread impact of avian influenza viruses not only poses risks to birds, but also to humans. The viruses spread from birds to humans and from human to human In addition, mutation in the primary strain will increase the infectiousness of avian influenza. We developed a mathematical model of avian influenza for both bird and human populations. The effect of half-saturated incidence on transmission dynamics of the disease is investigated. The half-saturation constants determine the levels at which birds and humans contract avian influenza. To prevent the spread of avian influenza, the associated half-saturation constants must be increased, especially the half-saturation constant H m for humans with mutant strain. The quantity H m plays an essential role in determining the basic reproduction number of this model. Furthermore, by decreasing the rate β m at which human-to-human mutant influenza is contracted, an outbreak can be controlled more effectively. To combat the outbreak, we propose both pharmaceutical (vaccination) and non-pharmaceutical (personal protection and isolation) control methods to reduce the transmission of avian influenza. Vaccination and personal protection will decrease β m, while isolation will increase H m. Numerical simulations demonstrate that all proposed control strategies will lead to disease eradication; however, if we only employ vaccination, it will require slightly longer to eradicate the disease than only applying non-pharmaceutical or a combination of pharmaceutical and non-pharmaceutical control methods. In conclusion, it is important to adopt a combination of control methods to fight an avian influenza outbreak.

  3. A mathematical model of avian influenza with half-saturated incidence.

    PubMed

    Chong, Nyuk Sian; Tchuenche, Jean Michel; Smith, Robert J

    2014-03-01

    The widespread impact of avian influenza viruses not only poses risks to birds, but also to humans. The viruses spread from birds to humans and from human to human In addition, mutation in the primary strain will increase the infectiousness of avian influenza. We developed a mathematical model of avian influenza for both bird and human populations. The effect of half-saturated incidence on transmission dynamics of the disease is investigated. The half-saturation constants determine the levels at which birds and humans contract avian influenza. To prevent the spread of avian influenza, the associated half-saturation constants must be increased, especially the half-saturation constant H m for humans with mutant strain. The quantity H m plays an essential role in determining the basic reproduction number of this model. Furthermore, by decreasing the rate β m at which human-to-human mutant influenza is contracted, an outbreak can be controlled more effectively. To combat the outbreak, we propose both pharmaceutical (vaccination) and non-pharmaceutical (personal protection and isolation) control methods to reduce the transmission of avian influenza. Vaccination and personal protection will decrease β m, while isolation will increase H m. Numerical simulations demonstrate that all proposed control strategies will lead to disease eradication; however, if we only employ vaccination, it will require slightly longer to eradicate the disease than only applying non-pharmaceutical or a combination of pharmaceutical and non-pharmaceutical control methods. In conclusion, it is important to adopt a combination of control methods to fight an avian influenza outbreak. PMID:23733366

  4. Detection of evolutionarily distinct avian influenza a viruses in antarctica.

    PubMed

    Hurt, Aeron C; Vijaykrishna, Dhanasekaran; Butler, Jeffrey; Baas, Chantal; Maurer-Stroh, Sebastian; Silva-de-la-Fuente, M Carolina; Medina-Vogel, Gonzalo; Olsen, Bjorn; Kelso, Anne; Barr, Ian G; González-Acuña, Daniel

    2014-01-01

    ABSTRACT Distinct lineages of avian influenza viruses (AIVs) are harbored by spatially segregated birds, yet significant surveillance gaps exist around the globe. Virtually nothing is known from the Antarctic. Using virus culture, molecular analysis, full genome sequencing, and serology of samples from Adélie penguins in Antarctica, we confirmed infection by H11N2 subtype AIVs. Their genetic segments were distinct from all known contemporary influenza viruses, including South American AIVs, suggesting spatial separation from other lineages. Only in the matrix and polymerase acidic gene phylogenies did the Antarctic sequences form a sister relationship to South American AIVs, whereas distant phylogenetic relationships were evident in all other gene segments. Interestingly, their neuraminidase genes formed a distant relationship to all avian and human influenza lineages, and the polymerase basic 1 and polymerase acidic formed a sister relationship to the equine H3N8 influenza virus lineage that emerged during 1963 and whose avian origins were previously unknown. We also estimated that each gene segment had diverged for 49 to 80 years from its most closely related sequences, highlighting a significant gap in our AIV knowledge in the region. We also show that the receptor binding properties of the H11N2 viruses are predominantly avian and that they were unable to replicate efficiently in experimentally inoculated ferrets, suggesting their continuous evolution in avian hosts. These findings add substantially to our understanding of both the ecology and the intra- and intercontinental movement of Antarctic AIVs and highlight the potential risk of an incursion of highly pathogenic AIVs into this fragile environment. IMPORTANCE Avian influenza viruses (AIVs) are typically maintained and spread by migratory birds, resulting in the existence of distinctly different viruses around the world. However, AIVs have not previously been detected in Antarctica. In this study, we

  5. Detection of evolutionarily distinct avian influenza a viruses in antarctica.

    PubMed

    Hurt, Aeron C; Vijaykrishna, Dhanasekaran; Butler, Jeffrey; Baas, Chantal; Maurer-Stroh, Sebastian; Silva-de-la-Fuente, M Carolina; Medina-Vogel, Gonzalo; Olsen, Bjorn; Kelso, Anne; Barr, Ian G; González-Acuña, Daniel

    2014-01-01

    ABSTRACT Distinct lineages of avian influenza viruses (AIVs) are harbored by spatially segregated birds, yet significant surveillance gaps exist around the globe. Virtually nothing is known from the Antarctic. Using virus culture, molecular analysis, full genome sequencing, and serology of samples from Adélie penguins in Antarctica, we confirmed infection by H11N2 subtype AIVs. Their genetic segments were distinct from all known contemporary influenza viruses, including South American AIVs, suggesting spatial separation from other lineages. Only in the matrix and polymerase acidic gene phylogenies did the Antarctic sequences form a sister relationship to South American AIVs, whereas distant phylogenetic relationships were evident in all other gene segments. Interestingly, their neuraminidase genes formed a distant relationship to all avian and human influenza lineages, and the polymerase basic 1 and polymerase acidic formed a sister relationship to the equine H3N8 influenza virus lineage that emerged during 1963 and whose avian origins were previously unknown. We also estimated that each gene segment had diverged for 49 to 80 years from its most closely related sequences, highlighting a significant gap in our AIV knowledge in the region. We also show that the receptor binding properties of the H11N2 viruses are predominantly avian and that they were unable to replicate efficiently in experimentally inoculated ferrets, suggesting their continuous evolution in avian hosts. These findings add substantially to our understanding of both the ecology and the intra- and intercontinental movement of Antarctic AIVs and highlight the potential risk of an incursion of highly pathogenic AIVs into this fragile environment. IMPORTANCE Avian influenza viruses (AIVs) are typically maintained and spread by migratory birds, resulting in the existence of distinctly different viruses around the world. However, AIVs have not previously been detected in Antarctica. In this study, we

  6. Avian influenza virus A/HK/483/97(H5N1) NS1 protein induces apoptosis in human airway epithelial cells.

    PubMed

    Lam, W Y; Tang, Julian W; Yeung, Apple C M; Chiu, Lawrence C M; Sung, Joseph J Y; Chan, Paul K S

    2008-03-01

    Avian H5N1 influenza virus causes a remarkably severe disease in humans, with an overall case fatality rate of greater than 50%. Human influenza A viruses induce apoptosis in infected cells, which can lead to organ dysfunction. To verify the role of H5N1-encoded NS1 in inducing apoptosis, the NS1 gene was cloned and expressed in human airway epithelial cells (NCI-H292 cells). The apoptotic events posttransfection were examined by a terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick-end-labeling assay, flow cytometric measurement of propidium iodide, annexin V staining, and Western blot analyses with antibodies specific for proapoptotic and antiapoptotic proteins. We demonstrated that the expression of H5N1 NS1 protein in NCI-H292 cells was sufficient to induce apoptotic cell death. Western blot analyses also showed that there was prominent cleavage of poly(ADP-ribose) polymerase and activation of caspase-3, caspase-7, and caspase-8 during the NS1-induced apoptosis. The results of caspase inhibitor assays further confirmed the involvement of caspase-dependent pathways in the NS1-induced apoptosis. Interestingly, the ability of H5N1 NS1 protein to induce apoptosis was much enhanced in cells pretreated with Fas ligand (the time posttransfection required to reach >30% apoptosis was reduced from 24 to 6 h). Furthermore, 24 h posttransfection, an increase in Fas ligand mRNA expression of about 5.6-fold was detected in cells transfected with H5N1 NS1. In conclusion, we demonstrated that the NS1 protein encoded by avian influenza A virus H5N1 induced apoptosis in human lung epithelial cells, mainly via the caspase-dependent pathway, which encourages further investigation into the potential for the NS1 protein to be a novel therapeutic target.

  7. Clinical features of avian influenza in Egyptian patients.

    PubMed

    Ashour, Maamoun Mohamad; Khatab, Adel Mahmoud; El-Folly, Runia Fouad; Amer, Wegdan Ahmad Fouad

    2012-08-01

    The clinical manifestations associated with H5N1 infection in humans range from asymptomatic infection to mild upper respiratory illness, severe pneumonia, and multiple organ failure. The ratio of symptomatic cases to asymptomatic cases is not known, because it is not possible to precisely define the number of asymptomatic cases. A total of 97 cases suffering from avian flu were suspected based on history taking, demographic data, clinical manifestations, laboratory and radiological investigations. The followings were done for all cases; complete blood picture (differential leucocytic count), coagulation profile, renal and liver function tests. H5N1 influenza virus was diagnosed thorough PCR technique. Changes in arterial blood gases and repeated chest X-rays were reported frequently. All patients were given specific antiviral therapy (oseltamivir). The study described the clinical picture and laboratory results of 81 confirmed avian influenza human cases in an Egyptian hospital (Abassia chest hospital), and reviewed the avian influenza current situation covering from March 2006 to June 2009 with very high pick in the first half of 2009. The significant apparent symptoms were fever as initial and main symptom (93.75%), followed by shortness of breathing (73%), cough (66.6%), muscle & joint pain (60%) and sore throat (40%).

  8. Analysis of the influenza virus gene pool of avian species from southern China.

    PubMed

    Lin, Y P; Shu, L L; Wright, S; Bean, W J; Sharp, G B; Shortridge, K F; Webster, R G

    1994-02-01

    Although Southern China has been considered the epicenter of human influenza pandemics, little is known about the genetic composition of influenza viruses in lower mammals or birds in that region. To provide information on the molecular epidemiology of these viruses, we used dot blot hybridization and phylogenetic methods to study the internal genes (PB1, PB2, PA, NP, M, and NS) of 106 avian influenza A viruses isolated from a total of 11,798 domestic ducks, chickens, and geese raised in Southern China including Hong Kong. All 636 genes examined were characteristic of avian influenza viruses; no human or swine influenza genes were detected. Thus, influenza virus reassortants do not appear to be maintained in the domesticated birds of Southeast Asia, eliminating opportunities for further gene reassortment. Phylogenetic analysis showed that the internal genes of these viruses belong to the Eurasian avian lineage, supporting geographical separation of the major avian lineages. The PB1 genes were most similar to A/Singapore/57 (H2N2) and Hong Kong (H3N2) viral genes, supporting an avian origin for the recent human H2N2 and H3N2 pandemic strains. The majority of internal genes from avian influenza viruses in Southern China belong to the Eurasian lineage and are similar to viruses that have recently been transmitted to humans, swine, and horses. This study provides evidence that the transmission of avian influenza viruses and their genes to other species is unidirectional and that the transmission of mammalian influenza virus strains to domestic poultry is probably not a factor in the generation of new pandemic strains.

  9. Practical aspects of vaccination of poultry against avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although little has changed in vaccine technology for avian influenza virus (AIV) in the past 20 years, the approach to vaccination of poultry (chickens, turkeys and ducks) for avian influenza has evolved as highly pathogenic (HP) AIV has become endemic in several regions of the world. Vaccination f...

  10. Experimental vaccinations for avian influenza virus including DIVA approaches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) is a viral disease of poultry that remains an economic threat to commercial poultry throughout the world by negatively impacting animal health and trade. Strategies to control avian influenza (AI) virus are developed to prevent, manage or eradicate the virus from the country, re...

  11. Limited human-to-human transmission of avian influenza A(H7N9) virus, Shanghai, China, March to April 2013.

    PubMed

    Hu, J; Zhu, Y; Zhao, B; Li, J; Liu, L; Gu, K; Zhang, W; Su, H; Teng, Z; Tang, S; Yuan, Z; Feng, Z; Wu, F

    2014-01-01

    In April 2013, two members of one family were successively confirmed as cases of avian influenza A(H7N9) virus infection in Shanghai, China. Respiratory specimens from the two cases and their close contacts were tested using real-time reverse-transcription (RT)-PCR. Paired serum specimens from contacts were tested by haemagglutination inhibition assay and microneutralisation test. The index patient developed severe pneumonia. Her husband presented with pneumonia shortly thereafter. Both cases had highly similar clinical features and infection with A(H7N9) virus was confirmed in both cases by genetic analysis. Phylogenetic analysis revealed a high level of similarity between the sequences from the two patients and environmental samples collected from wet markets in Minhang and Changning districts. Six samples from the Changning wet market were confirmed as A(H7N9) positive. Of 27 close contacts, one developed mild respiratory symptoms and another tested positive for A(H7N9) antibodies, but both were negative by real-time RT-PCR. The other 25 close contacts of both cases were A(H7N9) negative. Limited human-to-human transmission of the virus most likely occurred in the family cluster. However, other close contacts did not test positive for the virus, suggesting limited potential for extensive human-to-human transmission of the virus.

  12. New USDA licensed avian influenza vaccine (rHVT-AI) for protection against H5 avian influenza and usage discussion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, a new avian influenza vaccine was licensed by USDA for use in the United States for protection of commercial poultry. The vaccine is a recombinant herpes virus of turkeys expressing the hemagglutinin gene of an H5 subtype avian influenza virus belonging to the 2.2 clade of the H5N1 highly ...

  13. Novel avian influenza A (H5N6) viruses isolated in migratory waterfowl before the first human case reported in China, 2014.

    PubMed

    Bi, Yuhai; Liu, Haizhou; Xiong, Chaochao; Di Liu; Shi, Weifeng; Li, Mingxin; Liu, Siling; Chen, Jing; Chen, Guang; Li, Yong; Yang, Guoxiang; Lei, Yongsong; Xiong, Yanping; Lei, Fumin; Wang, Hanzhong; Chen, Quanjiao; Chen, Jianjun; Gao, George F

    2016-01-01

    In May 2014, China formally confirmed the first human infection with the novel H5N6 avian influenza virus (AIV) in Sichuan Province. Before the first human case was reported, surveillance of AIVs in wild birds resulted in the detection of three H5N6 viruses in faecal samples from migratory waterfowl in Chenhu wetlands, Hubei Province, China. Genetic and phylogenetic analyses revealed that these three novel viruses were closely related to the H5N6 virus that has caused human infections in China since 2014. A Bayesian phylogenetic reconstruction of all eight segments suggests multiple reassortment events in the evolution of these viruses. The hemagglutinin (HA) and neuraminidase (NA) originated from the H5N2 and H6N6 AIVs, respectively, whereas all six internal genes were derived from avian H5N1 viruses. The reassortant may have occurred in eastern China during 2012-2013. A phylogeographic analysis of the HA and NA genes traced the viruses to southern China, from where they spread to other areas via eastern China. A receptor-binding test showed that H5N6 viruses from migratory waterfowl had human-type receptor-binding activity, suggesting a potential for transmission to humans. These data suggest that migratory waterfowl may play a role in the dissemination of novel H5N6 viruses. PMID:27431568

  14. Novel avian influenza A (H5N6) viruses isolated in migratory waterfowl before the first human case reported in China, 2014

    PubMed Central

    Bi, Yuhai; Liu, Haizhou; Xiong, Chaochao; Di Liu; Shi, Weifeng; Li, Mingxin; Liu, Siling; Chen, Jing; Chen, Guang; Li, Yong; Yang, Guoxiang; Lei, Yongsong; Xiong, Yanping; Lei, Fumin; Wang, Hanzhong; Chen, Quanjiao; Chen, Jianjun; Gao, George F.

    2016-01-01

    In May 2014, China formally confirmed the first human infection with the novel H5N6 avian influenza virus (AIV) in Sichuan Province. Before the first human case was reported, surveillance of AIVs in wild birds resulted in the detection of three H5N6 viruses in faecal samples from migratory waterfowl in Chenhu wetlands, Hubei Province, China. Genetic and phylogenetic analyses revealed that these three novel viruses were closely related to the H5N6 virus that has caused human infections in China since 2014. A Bayesian phylogenetic reconstruction of all eight segments suggests multiple reassortment events in the evolution of these viruses. The hemagglutinin (HA) and neuraminidase (NA) originated from the H5N2 and H6N6 AIVs, respectively, whereas all six internal genes were derived from avian H5N1 viruses. The reassortant may have occurred in eastern China during 2012–2013. A phylogeographic analysis of the HA and NA genes traced the viruses to southern China, from where they spread to other areas via eastern China. A receptor-binding test showed that H5N6 viruses from migratory waterfowl had human-type receptor-binding activity, suggesting a potential for transmission to humans. These data suggest that migratory waterfowl may play a role in the dissemination of novel H5N6 viruses. PMID:27431568

  15. Avian Influenza Viruses, Inflammation, and CD8(+) T Cell Immunity.

    PubMed

    Wang, Zhongfang; Loh, Liyen; Kedzierski, Lukasz; Kedzierska, Katherine

    2016-01-01

    Avian influenza viruses (AIVs) circulate naturally in wild aquatic birds, infect domestic poultry, and are capable of causing sporadic bird-to-human transmissions. AIVs capable of infecting humans include a highly pathogenic AIV H5N1, first detected in humans in 1997, and a low pathogenic AIV H7N9, reported in humans in 2013. Both H5N1 and H7N9 cause severe influenza disease in humans, manifested by acute respiratory distress syndrome, multi-organ failure, and high mortality rates of 60% and 35%, respectively. Ongoing circulation of H5N1 and H7N9 viruses in wild birds and poultry, and their ability to infect humans emphasizes their epidemic and pandemic potential and poses a public health threat. It is, thus, imperative to understand the host immune responses to the AIVs so we can control severe influenza disease caused by H5N1 or H7N9 and rationally design new immunotherapies and vaccines. This review summarizes our current knowledge on AIV epidemiology, disease symptoms, inflammatory processes underlying the AIV infection in humans, and recent studies on universal pre-existing CD8(+) T cell immunity to AIVs. Immune responses driving the host recovery from AIV infection in patients hospitalized with severe influenza disease are also discussed.

  16. Avian Influenza Viruses, Inflammation, and CD8+ T Cell Immunity

    PubMed Central

    Wang, Zhongfang; Loh, Liyen; Kedzierski, Lukasz; Kedzierska, Katherine

    2016-01-01

    Avian influenza viruses (AIVs) circulate naturally in wild aquatic birds, infect domestic poultry, and are capable of causing sporadic bird-to-human transmissions. AIVs capable of infecting humans include a highly pathogenic AIV H5N1, first detected in humans in 1997, and a low pathogenic AIV H7N9, reported in humans in 2013. Both H5N1 and H7N9 cause severe influenza disease in humans, manifested by acute respiratory distress syndrome, multi-organ failure, and high mortality rates of 60% and 35%, respectively. Ongoing circulation of H5N1 and H7N9 viruses in wild birds and poultry, and their ability to infect humans emphasizes their epidemic and pandemic potential and poses a public health threat. It is, thus, imperative to understand the host immune responses to the AIVs so we can control severe influenza disease caused by H5N1 or H7N9 and rationally design new immunotherapies and vaccines. This review summarizes our current knowledge on AIV epidemiology, disease symptoms, inflammatory processes underlying the AIV infection in humans, and recent studies on universal pre-existing CD8+ T cell immunity to AIVs. Immune responses driving the host recovery from AIV infection in patients hospitalized with severe influenza disease are also discussed. PMID:26973644

  17. Emerging Infections of CNS: Avian Influenza A, Rift Valley Fever and Human Parecho Viruses

    PubMed Central

    Wiley, Clayton A.; Bhardwaj, Nitin; Ross, Ted M.; Bissel, Stephanie J.

    2015-01-01

    History is replete with emergent pandemic infections that have decimated the human population. Given the shear mass of humans that now crowd the earth, there is every reason to suspect history will repeat itself. We describe three RNA viruses that have recently emerged in the human population to mediate severe neurological disease. These new diseases are results of new mutations in the infectious agents or new exposure pathways to the agents or both. To appreciate their pathogenesis, we summarize the essential virology and immune response to each agent. Infection is described in the context of known host defenses. Once the viruses evade immune defenses and enter CNS cells, they rapidly co-opt host RNA processing to a cataclysmic extent. It is not clear why the brain is particularly susceptible to RNA viruses; but perhaps because of its tremendous dependence on RNA processing for physiological functioning, classical mechanisms of host defense (e.g. interferon disruption of viral replication) are diminished or not available. Effectiveness of immunity, immunization and pharmacological therapies is reviewed to contextualize the scope of the public health challenge. Unfortunately, vaccines that confer protection from systemic disease do not necessarily confer protection for the brain after exposure through unconventional routes. PMID:26276027

  18. Emerging Infections of CNS: Avian Influenza A Virus, Rift Valley Fever Virus and Human Parechovirus.

    PubMed

    Wiley, Clayton A; Bhardwaj, Nitin; Ross, Ted M; Bissel, Stephanie J

    2015-09-01

    History is replete with emergent pandemic infections that have decimated the human population. Given the shear mass of humans that now crowd the earth, there is every reason to suspect history will repeat itself. We describe three RNA viruses that have recently emerged in the human population to mediate severe neurological disease. These new diseases are results of new mutations in the infectious agents or new exposure pathways to the agents or both. To appreciate their pathogenesis, we summarize the essential virology and immune response to each agent. Infection is described in the context of known host defenses. Once the viruses evade immune defenses and enter central nervous system (CNS) cells, they rapidly co-opt host RNA processing to a cataclysmic extent. It is not clear why the brain is particularly susceptible to RNA viruses; but perhaps because of its tremendous dependence on RNA processing for physiological functioning, classical mechanisms of host defense (eg, interferon disruption of viral replication) are diminished or not available. Effectiveness of immunity, immunization and pharmacological therapies is reviewed to contextualize the scope of the public health challenge. Unfortunately, vaccines that confer protection from systemic disease do not necessarily confer protection for the brain after exposure through unconventional routes.

  19. Pro-inflammatory cytokine dysregulation is associated with novel avian influenza A (H7N9) virus in primary human macrophages.

    PubMed

    Zhao, Chihao; Qi, Xian; Ding, Meng; Sun, Xinlei; Zhou, Zhen; Zhang, Shuo; Zen, Ke; Li, Xihan

    2016-02-01

    Since March 2013, more than 500 laboratory-confirmed human H7N9 influenza A virus infection cases have been recorded, with a case fatality rate of more than 30%. Clinical research has shown that cytokine and chemokine dysregulation contributes to the pathogenicity of the H7N9 virus. Here, we investigated cytokine profiles in primary human macrophages infected with the novel H7N9 virus, using cytokine antibody arrays. The levels of several pro-inflammatory cytokines, particularly TNF-α, were increased in H7N9-infected macrophages. Induction of the transcriptional and translational levels of the pro-inflammatory cytokines by H7N9 virus seemed to be intermediate between those induced by highly pathogenic avian H5N1 and pandemic human H1N1 viruses, which were detected by ELISA and real-time quantitative PCR, respectively. Additionally, compared with H5N1, the upregulation of pro-inflammatory cytokines caused by H7N9 infection occurred rapidly but mildly. Our results identified the overall profiles of cytokine and chemokine induction by the H7N9 influenza virus in an in vitro cell-culture model, and could provide potential therapeutic targets for the control of severe human H7N9 disease.

  20. Pro-inflammatory cytokine dysregulation is associated with novel avian influenza A (H7N9) virus in primary human macrophages.

    PubMed

    Zhao, Chihao; Qi, Xian; Ding, Meng; Sun, Xinlei; Zhou, Zhen; Zhang, Shuo; Zen, Ke; Li, Xihan

    2016-02-01

    Since March 2013, more than 500 laboratory-confirmed human H7N9 influenza A virus infection cases have been recorded, with a case fatality rate of more than 30%. Clinical research has shown that cytokine and chemokine dysregulation contributes to the pathogenicity of the H7N9 virus. Here, we investigated cytokine profiles in primary human macrophages infected with the novel H7N9 virus, using cytokine antibody arrays. The levels of several pro-inflammatory cytokines, particularly TNF-α, were increased in H7N9-infected macrophages. Induction of the transcriptional and translational levels of the pro-inflammatory cytokines by H7N9 virus seemed to be intermediate between those induced by highly pathogenic avian H5N1 and pandemic human H1N1 viruses, which were detected by ELISA and real-time quantitative PCR, respectively. Additionally, compared with H5N1, the upregulation of pro-inflammatory cytokines caused by H7N9 infection occurred rapidly but mildly. Our results identified the overall profiles of cytokine and chemokine induction by the H7N9 influenza virus in an in vitro cell-culture model, and could provide potential therapeutic targets for the control of severe human H7N9 disease. PMID:26644088

  1. Differences in the epidemiology and virology of mild, severe and fatal human infections with avian influenza A (H7N9) virus.

    PubMed

    Sha, Jianping; Chen, Xiaowen; Ren, Yajin; Chen, Haijun; Wu, Zuqun; Ying, Dong; Zhang, Zhiruo; Liu, Shelan

    2016-05-01

    A novel avian influenza A (H7N9) virus caused 5-10 % mild and 30.5 % fatal human infections as of December 10, 2015. In order to investigate the reason for the higher rate of fatal outcome of this infection, this study compared the molecular epidemiology and virology of avian influenza A (H7N9) viruses from mild (N = 14), severe (N = 50) and fatal (N = 35) cases, as well as from non-human hosts (N = 73). The epidemiological results showed that the average age of the people in the mild, severe and fatal groups was 27.6, 52 and 62 years old, respectively (p < 0.001). Males accounted for 42.9 % (6/14), 58.0 % (29/50), and 74.3 % (26/35) of cases in the mild, severe and fatal group respectively (p = 0.094). Median days from onset to start of antiviral treatment were 2, 5 and 7 days in the mild, severe and fatal group, respectively (p = 0.002). The median time from onset to discharge/death was 12, 40 and 19 days in the mild, severe and fatal group, respectively (p < 0.001). Analysis of whole genome sequences showed that PB2 (E627K), NA (R294K) and PA (V100A) mutations were markedly associated with an increased fatality rate, while HA (N276D) and PB2 (N559T) mutations were clearly related to mild cases. There were no differences in the genotypes, adaptation to mammalian hosts, and genetic identity between the three types of infection. In conclusion, advanced age and delayed confirmation of diagnosis and antiviral intervention were risk factors for death. Furthermore, PB2 (E627K), NA (R294K) and PA (V100A) mutations might contribute to a fatal outcome in human H7N9 infection. PMID:26887968

  2. Differences in the epidemiology and virology of mild, severe and fatal human infections with avian influenza A (H7N9) virus.

    PubMed

    Sha, Jianping; Chen, Xiaowen; Ren, Yajin; Chen, Haijun; Wu, Zuqun; Ying, Dong; Zhang, Zhiruo; Liu, Shelan

    2016-05-01

    A novel avian influenza A (H7N9) virus caused 5-10 % mild and 30.5 % fatal human infections as of December 10, 2015. In order to investigate the reason for the higher rate of fatal outcome of this infection, this study compared the molecular epidemiology and virology of avian influenza A (H7N9) viruses from mild (N = 14), severe (N = 50) and fatal (N = 35) cases, as well as from non-human hosts (N = 73). The epidemiological results showed that the average age of the people in the mild, severe and fatal groups was 27.6, 52 and 62 years old, respectively (p < 0.001). Males accounted for 42.9 % (6/14), 58.0 % (29/50), and 74.3 % (26/35) of cases in the mild, severe and fatal group respectively (p = 0.094). Median days from onset to start of antiviral treatment were 2, 5 and 7 days in the mild, severe and fatal group, respectively (p = 0.002). The median time from onset to discharge/death was 12, 40 and 19 days in the mild, severe and fatal group, respectively (p < 0.001). Analysis of whole genome sequences showed that PB2 (E627K), NA (R294K) and PA (V100A) mutations were markedly associated with an increased fatality rate, while HA (N276D) and PB2 (N559T) mutations were clearly related to mild cases. There were no differences in the genotypes, adaptation to mammalian hosts, and genetic identity between the three types of infection. In conclusion, advanced age and delayed confirmation of diagnosis and antiviral intervention were risk factors for death. Furthermore, PB2 (E627K), NA (R294K) and PA (V100A) mutations might contribute to a fatal outcome in human H7N9 infection.

  3. USGS role and response to highly pathogenic avian influenza

    USGS Publications Warehouse

    Harris, M. Camille; Miles, A. Keith; Pearce, John M.; Prosser, Diann J.; Sleeman, Jonathan M.; Whalen, Mary E.

    2015-09-09

    Avian influenza viruses are naturally occurring in wild birds such as ducks, geese, swans, and gulls. These viruses generally do not cause illness in wild birds, however, when spread to poultry they can be highly pathogenic and cause illness and death in backyard and commercial farms. Outbreaks may cause devastating agricultural economic losses and some viral strains have the potential to infect people directly. Furthermore, the combination of avian influenza viruses with mammalian viruses can result in strains with the ability to transmit from person to person, possibly leading to viruses with pandemic potential. All known pandemic influenza viruses have had some genetic material of avian origin. Since 1996, a strain of highly pathogenic avian influenza (HPAI) virus, H5N1, has caused infection in wild birds, losses to poultry farms in Eurasia and North Africa, and led to the deaths of several hundred people. Spread of the H5N1 virus and other influenza strains from China was likely facilitated by migratory birds. In December 2014, HPAI was detected in poultry in Canada and migratory birds in the United States. Since then, HPAI viruses have spread to large parts of the United States and will likely continue to spread through migratory bird flyways and other mechanisms throughout North America. In the United States, HPAI viruses have severely affected the poultry industry with millions of domestic birds dead or culled. These strains of HPAI are not known to cause disease in humans; however, the Centers for Disease Control and Prevention (CDC) advise caution when in close contact with infected birds. Experts agree that HPAI strains currently circulating in wild birds of North America will likely persist for the next few years. This unprecedented situation presents risks to the poultry industry, natural resource management, and potentially human health. Scientific knowledge and decision support tools are urgently needed to understand factors affecting the persistence

  4. USGS role and response to highly pathogenic avian influenza

    USGS Publications Warehouse

    Harris, M. Camille; Miles, A. Keith; Pearce, John M.; Prosser, Diann J.; Sleeman, Jonathan M.; Whalen, Mary E.

    2015-01-01

    Avian influenza viruses are naturally occurring in wild birds such as ducks, geese, swans, and gulls. These viruses generally do not cause illness in wild birds, however, when spread to poultry they can be highly pathogenic and cause illness and death in backyard and commercial farms. Outbreaks may cause devastating agricultural economic losses and some viral strains have the potential to infect people directly. Furthermore, the combination of avian influenza viruses with mammalian viruses can result in strains with the ability to transmit from person to person, possibly leading to viruses with pandemic potential. All known pandemic influenza viruses have had some genetic material of avian origin. Since 1996, a strain of highly pathogenic avian influenza (HPAI) virus, H5N1, has caused infection in wild birds, losses to poultry farms in Eurasia and North Africa, and led to the deaths of several hundred people. Spread of the H5N1 virus and other influenza strains from China was likely facilitated by migratory birds. In December 2014, HPAI was detected in poultry in Canada and migratory birds in the United States. Since then, HPAI viruses have spread to large parts of the United States and will likely continue to spread through migratory bird flyways and other mechanisms throughout North America. In the United States, HPAI viruses have severely affected the poultry industry with millions of domestic birds dead or culled. These strains of HPAI are not known to cause disease in humans; however, the Centers for Disease Control and Prevention (CDC) advise caution when in close contact with infected birds. Experts agree that HPAI strains currently circulating in wild birds of North America will likely persist for the next few years. This unprecedented situation presents risks to the poultry industry, natural resource management, and potentially human health. Scientific knowledge and decision support tools are urgently needed to understand factors affecting the persistence

  5. Case-control study of risk factors for human infection with avian influenza A(H7N9) virus in Shanghai, China, 2013.

    PubMed

    Li, J; Chen, J; Yang, G; Zheng, Y X; Mao, S H; Zhu, W P; Yu, X L; Gao, Y; Pan, Q C; Yuan, Z A

    2015-07-01

    The first human infection with avian influenza A(H7N9) virus was reported in Shanghai, China in March 2013. An additional 32 cases of human H7N9 infection were identified in the following months from March to April 2013 in Shanghai. Here we conducted a case-control study of the patients with H7N9 infection (n = 25) using controls matched by age, sex, and residence to determine risk factors for H7N9 infection. Our findings suggest that chronic disease and frequency of visiting a live poultry market (>10 times, or 1-9 times during the 2 weeks before illness onset) were likely to be significantly associated with H7N9 infection, with the odds ratios being 4.07 [95% confidence interval (CI) 1.32-12.56], 10.61 (95% CI 1.85-60.74), and 3.76 (95% CI 1.31-10.79), respectively. Effective strategies for live poultry market control should be reinforced and ongoing education of the public is warranted to promote behavioural changes that can help to eliminate direct or indirect contact with influenza A(H7N9) virus.

  6. Pandemic potential of avian influenza A (H7N9) viruses.

    PubMed

    Watanabe, Tokiko; Watanabe, Shinji; Maher, Eileen A; Neumann, Gabriele; Kawaoka, Yoshihiro

    2014-11-01

    Avian influenza viruses rarely infect humans, but the recently emerged avian H7N9 influenza viruses have caused sporadic infections in humans in China, resulting in 440 confirmed cases with 122 fatalities as of 16 May 2014. In addition, epidemiologic surveys suggest that there have been asymptomatic or mild human infections with H7N9 viruses. These viruses replicate efficiently in mammals, show limited transmissibility in ferrets and guinea pigs, and possess mammalian-adapting amino acid changes that likely contribute to their ability to infect mammals. In this review, we summarize the characteristic features of the novel H7N9 viruses and assess their pandemic potential.

  7. Characterizing Loop Dynamics and Ligand Recognition in Human- and Avian-Type Influenza Neuraminidases via Generalized Born Molecular Dynamics and End-Point Free Energy Calculations

    SciTech Connect

    Amaro, Rommie E; Cheng, Xiaolin; Ivanov, Ivaylo N; Xu, Dong; McCammon, Jonathan

    2009-01-01

    The comparative dynamics and inhibitor binding free energies of group-1 and group-2 pathogenic influenza A subtype neuraminidase (NA) enzymes are of fundamental biological interest and relevant to structure-based drug design studies for antiviral compounds. In this work, we present seven generalized Born molecular dynamics simulations of avian (N1)- and human (N9)-type NAs in order to probe the comparative flexibility of the two subtypes, both with and without the inhibitor oseltamivir bound. The enhanced sampling obtained through the implicit solvent treatment suggests several provocative insights into the dynamics of the two subtypes, including that the group-2 enzymes may exhibit similar motion in the 430-binding site regions but different 150-loop motion. End-point free energy calculations elucidate the contributions to inhibitor binding free energies and suggest that entropic considerations cannot be neglected when comparing across the subtypes. We anticipate the findings presented here will have broad implications for the development of novel antiviral compounds against both seasonal and pandemic influenza strains.

  8. Serological and virological surveillance of avian influenza A virus H9N2 subtype in humans and poultry in Shanghai, China, between 2008 and 2010.

    PubMed

    Wang, Q; Ju, L; Liu, P; Zhou, J; Lv, X; Li, L; Shen, H; Su, H; Jiang, L; Jiang, Q

    2015-03-01

    We report the serological evidence of low-pathogenic avian influenza (LPAI) H9N2 infection in an occupational poultry-exposed population and a general population. A serological survey of an occupational poultry-exposed population and a general population was conducted using a haemagglutinin-inhibiting (HI) assay in Shanghai, China, from January 2008 to December 2010. Evidence of higher anti-H9 antibodies was found in serum samples collected from poultry workers. During this period, 239 H9N2 avian influenza viruses (AIVs) were isolated from 9297 tracheal and cloacal paired specimens collected from the poultry in live poultry markets. In addition, a total of 733 influenza viruses were isolated from 1569 nasal and throat swabs collected from patients with influenza-like symptoms in a sentinel hospital, which include H3N2, H1N1, pandemic H1N1 and B, but no H9N2 virus was detected. These findings highlight the need for long-term surveillance of avian influenza viruses in occupational poultry-exposed workers.

  9. Serological and Virological Surveillance of Avian Influenza A Virus H9N2 Subtype in Humans and Poultry in Shanghai, China, Between 2008 and 2010

    PubMed Central

    Wang, Q; Ju, L; Liu, P; Zhou, J; Lv, X; Li, L; Shen, H; Su, H; Jiang, L; Jiang, Q

    2015-01-01

    We report the serological evidence of low-pathogenic avian influenza (LPAI) H9N2 infection in an occupational poultry-exposed population and a general population. A serological survey of an occupational poultry-exposed population and a general population was conducted using a haemagglutinin-inhibiting (HI) assay in Shanghai, China, from January 2008 to December 2010. Evidence of higher anti-H9 antibodies was found in serum samples collected from poultry workers. During this period, 239 H9N2 avian influenza viruses (AIVs) were isolated from 9297 tracheal and cloacal paired specimens collected from the poultry in live poultry markets. In addition, a total of 733 influenza viruses were isolated from 1569 nasal and throat swabs collected from patients with influenza-like symptoms in a sentinel hospital, which include H3N2, H1N1, pandemic H1N1 and B, but no H9N2 virus was detected. These findings highlight the need for long-term surveillance of avian influenza viruses in occupational poultry-exposed workers. PMID:24803167

  10. Avian Influenza Virus Infection of Immortalized Human Respiratory Epithelial Cells Depends upon a Delicate Balance between Hemagglutinin Acid Stability and Endosomal pH.

    PubMed

    Daidoji, Tomo; Watanabe, Yohei; Ibrahim, Madiha S; Yasugi, Mayo; Maruyama, Hisataka; Masuda, Taisuke; Arai, Fumihito; Ohba, Tomoyuki; Honda, Ayae; Ikuta, Kazuyoshi; Nakaya, Takaaki

    2015-04-24

    The highly pathogenic avian influenza (AI) virus, H5N1, is a serious threat to public health worldwide. Both the currently circulating H5N1 and previously circulating AI viruses recognize avian-type receptors; however, only the H5N1 is highly infectious and virulent in humans. The mechanism(s) underlying this difference in infectivity remains unclear. The aim of this study was to clarify the mechanisms responsible for the difference in infectivity between the current and previously circulating strains. Primary human small airway epithelial cells (SAECs) were transformed with the SV40 large T-antigen to establish a series of clones (SAEC-Ts). These clones were then used to test the infectivity of AI strains. Human SAEC-Ts could be broadly categorized into two different types based on their susceptibility (high or low) to the viruses. SAEC-T clones were poorly susceptible to previously circulating AI but were completely susceptible to the currently circulating H5N1. The hemagglutinin (HA) of the current H5N1 virus showed greater membrane fusion activity at higher pH levels than that of previous AI viruses, resulting in broader cell tropism. Moreover, the endosomal pH was lower in high susceptibility SAEC-T clones than that in low susceptibility SAEC-T clones. Taken together, the results of this study suggest that the infectivity of AI viruses, including H5N1, depends upon a delicate balance between the acid sensitivity of the viral HA and the pH within the endosomes of the target cell. Thus, one of the mechanisms underlying H5N1 pathogenesis in humans relies on its ability to fuse efficiently with the endosomes in human airway epithelial cells.

  11. Avian Influenza Virus Infection of Immortalized Human Respiratory Epithelial Cells Depends upon a Delicate Balance between Hemagglutinin Acid Stability and Endosomal pH.

    PubMed

    Daidoji, Tomo; Watanabe, Yohei; Ibrahim, Madiha S; Yasugi, Mayo; Maruyama, Hisataka; Masuda, Taisuke; Arai, Fumihito; Ohba, Tomoyuki; Honda, Ayae; Ikuta, Kazuyoshi; Nakaya, Takaaki

    2015-04-24

    The highly pathogenic avian influenza (AI) virus, H5N1, is a serious threat to public health worldwide. Both the currently circulating H5N1 and previously circulating AI viruses recognize avian-type receptors; however, only the H5N1 is highly infectious and virulent in humans. The mechanism(s) underlying this difference in infectivity remains unclear. The aim of this study was to clarify the mechanisms responsible for the difference in infectivity between the current and previously circulating strains. Primary human small airway epithelial cells (SAECs) were transformed with the SV40 large T-antigen to establish a series of clones (SAEC-Ts). These clones were then used to test the infectivity of AI strains. Human SAEC-Ts could be broadly categorized into two different types based on their susceptibility (high or low) to the viruses. SAEC-T clones were poorly susceptible to previously circulating AI but were completely susceptible to the currently circulating H5N1. The hemagglutinin (HA) of the current H5N1 virus showed greater membrane fusion activity at higher pH levels than that of previous AI viruses, resulting in broader cell tropism. Moreover, the endosomal pH was lower in high susceptibility SAEC-T clones than that in low susceptibility SAEC-T clones. Taken together, the results of this study suggest that the infectivity of AI viruses, including H5N1, depends upon a delicate balance between the acid sensitivity of the viral HA and the pH within the endosomes of the target cell. Thus, one of the mechanisms underlying H5N1 pathogenesis in humans relies on its ability to fuse efficiently with the endosomes in human airway epithelial cells. PMID:25673693

  12. Avian Influenza spread and transmission dynamics

    USGS Publications Warehouse

    Bourouiba, Lydia; Gourley, Stephen A.; Liu, Rongsong; Takekawa, John Y.; Wu, Jianhong; Chen, Dongmei; Moulin, Bernard; Wu, Jianhong

    2015-01-01

    The spread of highly pathogenic avian influenza (HPAI) viruses of type A of subtype H5N1 has been a serious threat to global public health. Understanding the roles of various (migratory, wild, poultry) bird species in the transmission of these viruses is critical for designing and implementing effective control and intervention measures. Developing appropriate models and mathematical techniques to understand these roles and to evaluate the effectiveness of mitigation strategies have been a challenge. Recent development of the global health surveillance (especially satellite tracking and GIS techniques) and the mathematical theory of dynamical systems combined have gradually shown the promise of some cutting-edge methodologies and techniques in mathematical biology to meet this challenge.

  13. Design of Multiplexed Detection Assays for Identification of Avian Influenza A Virus Subtypes Pathogenic to Humans by SmartCycler Real-Time Reverse Transcription-PCR ▿

    PubMed Central

    Wang, Wei; Ren, Peijun; Mardi, Sek; Hou, Lili; Tsai, Cheguo; Chan, Kwok Hung; Cheng, Peter; Sheng, Jun; Buchy, Philippe; Sun, Bing; Toyoda, Tetsuya; Lim, Wilina; Peiris, J. S. Malik; Zhou, Paul; Deubel, Vincent

    2009-01-01

    Influenza A virus (IAV) epidemics are the result of human-to-human or poultry-to-human transmission. Tracking seasonal outbreaks of IAV and other avian influenza virus (AIV) subtypes that can infect humans, aquatic and migratory birds, poultry, and pigs is essential for epidemiological surveillance and outbreak alerts. In this study, we performed four real-time reverse transcription-PCR (rRT-PCR) assays for identification of the IAV M and hemagglutinin (HA) genes from six known AIVs infecting pigs, birds, and humans. IAV M1 gene-positive samples tested by single-step rRT-PCR and a fluorogenic Sybr green I detection system were further processed for H5 subtype identification by using two-primer-set multiplex and Sybr green I rRT-PCR assays. H5 subtype-negative samples were then tested with either a TaqMan assay for subtypes H1 and H3 or a TaqMan assay for subtypes H2, H7, and H9 and a beacon multiplex rRT-PCR identification assay. The four-tube strategy was able to detect 10 RNA copies of the HA genes of subtypes H1, H2, H3, H5, and H7 and 100 RNA copies of the HA gene of subtype H9. At least six H5 clades of H5N1 viruses isolated in Southeast Asia and China were detected by that test. Using rRT-PCR assays for the M1 and HA genes in 202 nasopharyngeal swab specimens from children with acute respiratory infections, we identified a total of 39 samples positive for the IAV M1 gene and subtypes H1 and H3. When performed with a portable SmartCycler instrument, the assays offer an efficient, flexible, and reliable platform for investigations of IAV and AIV in remote hospitals and in the field. PMID:18971359

  14. design of multiplexed detection assays for identification of avian influenza a virus subtypes pathogenic to humans by SmartCycler real-time reverse transcription-PCR.

    PubMed

    Wang, Wei; Ren, Peijun; Mardi, Sek; Hou, Lili; Tsai, Cheguo; Chan, Kwok Hung; Cheng, Peter; Sheng, Jun; Buchy, Philippe; Sun, Bing; Toyoda, Tetsuya; Lim, Wilina; Peiris, J S Malik; Zhou, Paul; Deubel, Vincent

    2009-01-01

    Influenza A virus (IAV) epidemics are the result of human-to-human or poultry-to-human transmission. Tracking seasonal outbreaks of IAV and other avian influenza virus (AIV) subtypes that can infect humans, aquatic and migratory birds, poultry, and pigs is essential for epidemiological surveillance and outbreak alerts. In this study, we performed four real-time reverse transcription-PCR (rRT-PCR) assays for identification of the IAV M and hemagglutinin (HA) genes from six known AIVs infecting pigs, birds, and humans. IAV M1 gene-positive samples tested by single-step rRT-PCR and a fluorogenic Sybr green I detection system were further processed for H5 subtype identification by using two-primer-set multiplex and Sybr green I rRT-PCR assays. H5 subtype-negative samples were then tested with either a TaqMan assay for subtypes H1 and H3 or a TaqMan assay for subtypes H2, H7, and H9 and a beacon multiplex rRT-PCR identification assay. The four-tube strategy was able to detect 10 RNA copies of the HA genes of subtypes H1, H2, H3, H5, and H7 and 100 RNA copies of the HA gene of subtype H9. At least six H5 clades of H5N1 viruses isolated in Southeast Asia and China were detected by that test. Using rRT-PCR assays for the M1 and HA genes in 202 nasopharyngeal swab specimens from children with acute respiratory infections, we identified a total of 39 samples positive for the IAV M1 gene and subtypes H1 and H3. When performed with a portable SmartCycler instrument, the assays offer an efficient, flexible, and reliable platform for investigations of IAV and AIV in remote hospitals and in the field.

  15. Global epidemiology of avian influenza A H5N1 virus infection in humans, 1997-2015: a systematic review of individual case data.

    PubMed

    Lai, Shengjie; Qin, Ying; Cowling, Benjamin J; Ren, Xiang; Wardrop, Nicola A; Gilbert, Marius; Tsang, Tim K; Wu, Peng; Feng, Luzhao; Jiang, Hui; Peng, Zhibin; Zheng, Jiandong; Liao, Qiaohong; Li, Sa; Horby, Peter W; Farrar, Jeremy J; Gao, George F; Tatem, Andrew J; Yu, Hongjie

    2016-07-01

    Avian influenza A H5N1 viruses have caused many, typically severe, human infections since the first human case was reported in 1997. However, no comprehensive epidemiological analysis of global human cases of H5N1 from 1997 to 2015 exists. Moreover, few studies have examined in detail the changing epidemiology of human H5N1 cases in Egypt, especially given the outbreaks since November, 2014, which have the highest number of cases ever reported worldwide in a similar period. Data on individual patients were collated from different sources using a systematic approach to describe the global epidemiology of 907 human H5N1 cases between May, 1997, and April, 2015. The number of affected countries rose between 2003 and 2008, with expansion from east and southeast Asia, then to west Asia and Africa. Most cases (67·2%) occurred from December to March, and the overall case-fatality risk was 483 (53·5%) of 903 cases which varied across geographical regions. Although the incidence in Egypt has increased dramatically since November, 2014, compared with the cases beforehand, there were no significant differences in the fatality risk, history of exposure to poultry, history of patient contact, and time from onset to hospital admission in the recent cases. PMID:27211899

  16. Freshwater clams as bioconcentrators of avian influenza virus in water.

    PubMed

    Huyvaert, Kathryn P; Carlson, Jenny S; Bentler, Kevin T; Cobble, Kacy R; Nolte, Dale L; Franklin, Alan B

    2012-10-01

    We report experimental evidence for bioconcentration of a low-pathogenicity avian influenza virus (H6N8) in the tissue of freshwater clams. Our results support the concept that freshwater clams may provide an effective tool for use in the early detection of influenza A viruses in aquatic environments. PMID:22925022

  17. Serological evidence of avian influenza virus and canine influenza virus infections among stray cats in live poultry markets, China.

    PubMed

    Zhou, Han; He, Shu-yi; Sun, Lingshuang; He, Huamei; Ji, Fangxiao; Sun, Yao; Jia, Kun; Ning, Zhangyong; Wang, Heng; Yuan, Liguo; Zhou, Pei; Zhang, Guihong; Li, Shoujun

    2015-02-25

    From January 2010 to January 2012, we collected sera samples from 700 stray cats living in close proximity to poultry farms or poultry markets in 4 provinces in China. A number of cats had evidence of avian and canine influenza virus infection: avian H9N2 [24 by HI ≥1:20 and 16 by microneutralization (MN) assay ≥1:80]; avian H5N1 (9 by HI ≥1:20 and 3 by MN assay ≥1:80) and canine H3N2 (32 by HI ≥1:20 and 18 by MN ≥1:80). Bivariate analyses revealed that cats sampled near live poultry markets and cats with influenza-like-illness were at increased risk of having elevated antibody titers by HI against avian H9N2, avian H5N1, or canine H3N2 viruses. Hence, cats may play a very important role in the ecology of novel influenza viruses and periodic epidemiological surveillance for novel influenza infections among stray cats could serve as an early warning system for human threats.

  18. 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...

  19. Purification of human and avian influenza viruses using cellulose sulfate ester (Cellufine Sulfate) in the process of vaccine production.

    PubMed

    Sakoda, Yoshihiro; Okamatsu, Masatoshi; Isoda, Norikazu; Yamamoto, Naoki; Ozaki, Koichi; Umeda, Yasuto; Aoyama, Shigeyuki; Kida, Hiroshi

    2012-07-01

    Affinity chromatography using sulfated, spherical cellulose beads (Cellufine Sulfate) was assessed for purification of influenza A and influenza B viruses. Recovery rates of viruses eluted from the beads were high for all tested virus strains. This method was also useful for removing chicken egg-derived impurities from allantoic fluids containing influenza viruses; the hemagglutination activity per amount of protein in the eluted sample was significantly higher than that in the applied sample. These results suggest that use of Cellufine Sulfate is a practical method for primary purification of influenza viruses in the process of influenza vaccine production.

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

    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.

  1. Efficacy of inactivated influenza vaccines for protection of poultry against the H7N9 low pathogenic avian influenza virus isolated in China during 2013

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The recent outbreak in China of avian influenza (AI) H7N9 in birds and humans underscores the interspecies movement of these viruses. Interestingly, the genetic composition of these H7N9 viruses appears to be solely of avian origin and of low pathogenicity in birds. Although few isolations of these ...

  2. A Complete Molecular Diagnostic Procedure for Applications in Surveillance and Subtyping of Avian Influenza Virus

    PubMed Central

    Tseng, Chun-Hsien; Tsai, Hsiang-Jung; Chang, Chung-Ming

    2014-01-01

    Introduction. The following complete molecular diagnostic procedure we developed, based on real-time quantitative PCR and traditional PCR, is effective for avian influenza surveillance, virus subtyping, and viral genome sequencing. Method. This study provides a specific and sensitive step-by-step procedure for efficient avian influenza identification of 16 hemagglutinin and 9 neuraminidase avian influenza subtypes. Result and Conclusion. This diagnostic procedure may prove exceedingly useful for virological and ecological advancements in global avian influenza research. PMID:25057497

  3. Surveillance and Analysis of Avian Influenza Viruses, Australia

    PubMed Central

    Warner, Simone; Tracey, John P.; Arzey, K. Edla; Selleck, Paul; O’Riley, Kim; Beckett, Emma L.; Bunn, Chris; Kirkland, Peter D.; Vijaykrishna, Dhanasekaran; Olsen, Bjorn; Hurt, Aeron C.

    2010-01-01

    We investigated carriage of avian influenza viruses by wild birds in Australia, 2005–2008, to assess the risks to poultry industries and human health. We collected 21,858 (7,357 cloacal, 14,501 fecal) samples and detected 300 viruses, representing a detection rate of ≈1.4%. Rates were highest in autumn (March–May) and differed substantially between bird types, areas, and years. We typed 107 avian influenza viruses and identified 19 H5, 8 H7, and 16 H9 (40% of typed viruses). All were of low pathogenicity. These viruses formed clearly different phylogenetic clades to lineages from Eurasia or North America, suggesting the potential existence of Australian lineages. H7 viruses were similar to highly pathogenic H7 strains that caused outbreaks in poultry in Australia. Several periods of increased detection rates (numbers or subtypes of viruses) were identified. This study demonstrates the need for ongoing surveillance to detect emerging pathogenic strains and facilitate prevention of outbreaks. PMID:21122219

  4. 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.

  5. Investigation of avian influenza virus in poultry and wild birds due to novel avian-origin influenza A(H10N8) in Nanchang City, China.

    PubMed

    Ni, Xiansheng; He, Fenglan; Hu, Maohong; Zhou, Xianfeng; Wang, Bin; Feng, Changhua; Wu, Yumei; Li, Youxing; Tu, Junling; Li, Hui; Liu, Mingbin; Chen, Haiying; Chen, Shengen

    2015-01-01

    Multiple reassortment events within poultry and wild birds had resulted in the establishment of another novel avian influenza A(H10N8) virus, and finally resulted in human death in Nanchang, China. However, there was a paucity of information on the prevalence of avian influenza virus in poultry and wild birds in Nanchang area. We investigated avian influenza virus in poultry and wild birds from live poultry markets, poultry countyards, delivery vehicles, and wild-bird habitats in Nanchang. We analyzed 1036 samples from wild birds and domestic poultry collected from December 2013 to February 2014. Original biological samples were tested for the presence of avian influenza virus using specific primer and probe sets of H5, H7, H9, H10 and N8 subtypes by real-time RT-PCR. In our analysis, the majority (97.98%) of positive samples were from live poultry markets. Among the poultry samples from chickens and ducks, AIV prevalence was 26.05 and 30.81%, respectively. Mixed infection of different HA subtypes was very common. Additionally, H10 subtypes coexistence with N8 was the most prevalent agent during the emergence of H10N8. This event illustrated a long-term surveillance was so helpful for pandemic preparedness and response.

  6. Inhibiting avian influenza virus shedding using a novel RNAi antiviral vector technology: proof of concept in an avian cell model.

    PubMed

    Linke, Lyndsey M; Wilusz, Jeffrey; Pabilonia, Kristy L; Fruehauf, Johannes; Magnuson, Roberta; Olea-Popelka, Francisco; Triantis, Joni; Landolt, Gabriele; Salman, Mo

    2016-03-01

    Influenza A viruses pose significant health and economic threats to humans and animals. Outbreaks of avian influenza virus (AIV) are a liability to the poultry industry and increase the risk for transmission to humans. There are limitations to using the AIV vaccine in poultry, creating barriers to controlling outbreaks and a need for alternative effective control measures. Application of RNA interference (RNAi) techniques hold potential; however, the delivery of RNAi-mediating agents is a well-known obstacle to harnessing its clinical application. We introduce a novel antiviral approach using bacterial vectors that target avian mucosal epithelial cells and deliver (small interfering RNA) siRNAs against two AIV genes, nucleoprotein (NP) and polymerase acidic protein (PA). Using a red fluorescent reporter, we first demonstrated vector delivery and intracellular expression in avian epithelial cells. Subsequently, we demonstrated significant reductions in AIV shedding when applying these anti-AIV vectors prophylactically. These antiviral vectors provided up to a 10,000-fold reduction in viral titers shed, demonstrating in vitro proof-of-concept for using these novel anti-AIV vectors to inhibit AIV shedding. Our results indicate this siRNA vector technology could represent a scalable and clinically applicable antiviral technology for avian and human influenza and a prototype for RNAi-based vectors against other viruses.

  7. Inhibiting avian influenza virus shedding using a novel RNAi antiviral vector technology: proof of concept in an avian cell model.

    PubMed

    Linke, Lyndsey M; Wilusz, Jeffrey; Pabilonia, Kristy L; Fruehauf, Johannes; Magnuson, Roberta; Olea-Popelka, Francisco; Triantis, Joni; Landolt, Gabriele; Salman, Mo

    2016-03-01

    Influenza A viruses pose significant health and economic threats to humans and animals. Outbreaks of avian influenza virus (AIV) are a liability to the poultry industry and increase the risk for transmission to humans. There are limitations to using the AIV vaccine in poultry, creating barriers to controlling outbreaks and a need for alternative effective control measures. Application of RNA interference (RNAi) techniques hold potential; however, the delivery of RNAi-mediating agents is a well-known obstacle to harnessing its clinical application. We introduce a novel antiviral approach using bacterial vectors that target avian mucosal epithelial cells and deliver (small interfering RNA) siRNAs against two AIV genes, nucleoprotein (NP) and polymerase acidic protein (PA). Using a red fluorescent reporter, we first demonstrated vector delivery and intracellular expression in avian epithelial cells. Subsequently, we demonstrated significant reductions in AIV shedding when applying these anti-AIV vectors prophylactically. These antiviral vectors provided up to a 10,000-fold reduction in viral titers shed, demonstrating in vitro proof-of-concept for using these novel anti-AIV vectors to inhibit AIV shedding. Our results indicate this siRNA vector technology could represent a scalable and clinically applicable antiviral technology for avian and human influenza and a prototype for RNAi-based vectors against other viruses. PMID:26910902

  8. When animal viruses attack: SARS and avian influenza.

    PubMed

    Lee, Paul J; Krilov, Leonard R

    2005-01-01

    SARS and avian influenza have many common features. They both arose in Asia and originated from animal viruses. They both have the potential to become pandemics because human beings lack antibodies to the animal-derived antigens present on the viral surface and rapid dissemination can occur from the relative ease and availability of high speed and far-reaching transportation methods. Pediatricians, in particular, should remain alert about the possibility of pandemic illnesses in their patients. Annual rates of influenza in children may be 1.5 to 3 times those in the adult population, and infection rates during a community epidemic may exceed 40% in preschool-aged children and 30% in school-aged children. Infected children also play a central role in disseminating influenza, as they are the major point of entry for the virus into the household, from which adults spread disease into the community. Of course, children younger than 24 months also are at high risk for complications from influenza. A 1999 Centers for Disease Control and Prevention projection of an influenza pandemic in the US paints a grim picture: 89,000 to 207,000 deaths, 314,000 to 734,000 hospitalizations, 18 million to 42 million outpatient visits, and 20 million to 47 million additional illnesses, at a cost to society of at least dollars 71.3 billion to dollars 166.5 billion. High-risk patients (15% of the population) would account for approximately 84% of all deaths. Although SARS has been kind to the pediatric population so far, there are no guarantees that future outbreaks would be as sparing. To aid readers in remaining up-to-date with SARS and avian influenza, some useful websites are listed in the Sidebar. Two masters of suspense, Alfred Hitchcock and Stephen King, may have been closer to the truth than they ever would have believed. Both birds and a super flu could bring about the end of civilization as we know it. But all is not lost--to paraphrase Thomas Jefferson, the price of health is

  9. 9 CFR 145.15 - Diagnostic surveillance program for low pathogenic avian influenza.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... low pathogenic avian influenza. 145.15 Section 145.15 Animals and Animal Products ANIMAL AND PLANT... pathogenic avian influenza. (a) The Official State Agency must develop a diagnostic surveillance program for H5/H7 low pathogenic avian influenza for all poultry in the State. The exact provisions of...

  10. 9 CFR 145.15 - Diagnostic surveillance program for low pathogenic avian influenza.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... low pathogenic avian influenza. 145.15 Section 145.15 Animals and Animal Products ANIMAL AND PLANT... pathogenic avian influenza. (a) The Official State Agency must develop a diagnostic surveillance program for H5/H7 low pathogenic avian influenza for all poultry in the State. The exact provisions of...

  11. 9 CFR 145.15 - Diagnostic surveillance program for low pathogenic avian influenza.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... low pathogenic avian influenza. 145.15 Section 145.15 Animals and Animal Products ANIMAL AND PLANT... pathogenic avian influenza. (a) The Official State Agency must develop a diagnostic surveillance program for H5/H7 low pathogenic avian influenza for all poultry in the State. The exact provisions of...

  12. Susceptibility of avian species to north american H13 low pathogenic avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gulls are widely recognized reservoirs for low pathogenic avian influenza (LPAI) viruses; however, the subtypes maintained in these populations and/or the transmission mechanisms involved are poorly understood. Although, a wide diversity of influenza viruses have been isolated from gulls, two hemag...

  13. Comparative susceptibility of avian species to low pathogenic avian influenza viruses of the H13 subtype

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gulls are widely recognized reservoirs for low pathogenic avian influenza (LPAI) viruses; however, the subtypes maintained in these populations and/or the transmission mechanisms involved are poorly understood. Although, a wide diversity of influenza viruses have been isolated from gulls, two hemag...

  14. In ovo and in vitro susceptibility of American alligators (Alligator mississippiensis) to avian influenza virus infection.

    PubMed

    Temple, Bradley L; Finger, John W; Jones, Cheryl A; Gabbard, Jon D; Jelesijevic, Tomislav; Uhl, Elizabeth W; Hogan, Robert J; Glenn, Travis C; Tompkins, S Mark

    2015-01-01

    Avian influenza has emerged as one of the most ubiquitous viruses within our biosphere. Wild aquatic birds are believed to be the primary reservoir of all influenza viruses; however, the spillover of H5N1 highly pathogenic avian influenza (HPAI) and the recent swine-origin pandemic H1N1 viruses have sparked increased interest in identifying and understanding which and how many species can be infected. Moreover, novel influenza virus sequences were recently isolated from New World bats. Crocodilians have a slow rate of molecular evolution and are the sister group to birds; thus they are a logical reptilian group to explore susceptibility to influenza virus infection and they provide a link between birds and mammals. A primary American alligator (Alligator mississippiensis) cell line, and embryos, were infected with four, low pathogenic avian influenza (LPAI) strains to assess susceptibility to infection. Embryonated alligator eggs supported virus replication, as evidenced by the influenza virus M gene and infectious virus detected in allantoic fluid and by virus antigen staining in embryo tissues. Primary alligator cells were also inoculated with the LPAI viruses and showed susceptibility based upon antigen staining; however, the requirement for trypsin to support replication in cell culture limited replication. To assess influenza virus replication in culture, primary alligator cells were inoculated with H1N1 human influenza or H5N1 HPAI viruses that replicate independent of trypsin. Both viruses replicated efficiently in culture, even at the 30 C temperature preferred by the alligator cells. This research demonstrates the ability of wild-type influenza viruses to infect and replicate within two crocodilian substrates and suggests the need for further research to assess crocodilians as a species potentially susceptible to influenza virus infection.

  15. 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.

  16. Attomolar detection of influenza A virus hemagglutinin human H1 and avian H5 using glycan-blotted field effect transistor biosensor.

    PubMed

    Hideshima, Sho; Hinou, Hiroshi; Ebihara, Daisuke; Sato, Ryosuke; Kuroiwa, Shigeki; Nakanishi, Takuya; Nishimura, Shin-Ichiro; Osaka, Tetsuya

    2013-06-18

    Influenza virus, through cell invasion and propagation with the interaction between hemagglutinin (HA) present on its surface and glycans on the host cell, causes a rapidly spreading infection throughout the world. In the present investigation, we succeeded for the first time in the attomolar-level sensing and discrimination of influenza A viral HA molecules H1 and H5 by using a glycan-immobilized field effect transistor (FET) biosensor. The small ligand glycans immobilized on the FET device, which make effective use of the charge-detectable region for FET-based detection in terms of Debye length, gave an advantage in the highly sensitive detection of the proteins. Two kinds of trisaccharides receptors terminating in sialic acid-α2,6-galactose (6'-sialyllactose) and in sialic acid-α2,3-galactose (3'-sialyllactose) were conjugated directly with the SiO2 surface of FET devices by a simple glycoblotting method using the self-assembled monolayer (SAM) of aminooxy terminated silane-coupling reagent, 3-aminooxypropyltriethoxysilane. Furthermore, it was demonstrated that the FETs with densely immobilized glycans, which possess the high capture ability by achieving the glycoside cluster effect, clearly distinguish HA molecules between their subtypes H1 (human) and H5 (avian) at the attomolar level, while the conventional method based on HA antibodies achieves only picomolar-level detection. Our findings indicate that the glycan-immobilized FET is a promising device to detect various pathogenic bacteria and viruses through glycan-protein interaction found ubiquitously in many infectious diseases. PMID:23675869

  17. Alleles A and B of non-structural protein 1 of avian influenza A viruses differentially inhibit beta interferon production in human and mink lung cells.

    PubMed

    Munir, Muhammad; Zohari, Siamak; Metreveli, Giorgi; Baule, Claudia; Belák, Sándor; Berg, Mikael

    2011-09-01

    Non-structural protein 1 (NS1) counteracts the production of host type I interferons (IFN-α/β) for the efficient replication and pathogenicity of influenza A viruses. Here, we reveal another dimension of the NS1 protein of avian influenza A viruses in suppressing IFN-β production in cultured cell lines. We found that allele A NS1 proteins of H6N8 and H4N6 have a strong capacity to inhibit the activation of IFN-β production, compared with allele B from corresponding subtypes, as measured by IFN stimulatory response element (ISRE) promoter activation, IFN-β mRNA transcription and IFN-β protein expression. Furthermore, the ability to suppress IFN-β promoter activation was mapped to the C-terminal effector domain (ED), while the RNA-binding domain (RBD) alone was unable to suppress IFN-β promoter activation. Chimeric studies indicated that when the RBD of allele A was fused to the ED of allele B, it was a strong inhibitor of IFN-β promoter activity. This shows that well-matched ED and RBD are crucial for the function of the NS1 protein and that the RBD could be one possible cause for this differential IFN-β inhibition. Notably, mutagenesis studies indicated that the F103Y and Y103F substitutions in alleles A and B, respectively, do not influence the ISRE promoter activation. Apart from dsRNA signalling, differences were observed in the expression pattern of NS1 in transfected human and mink lung cells. This study therefore expands the versatile nature of the NS1 protein in inhibiting IFN responses at multiple levels, by demonstrating for the first time that it occurs in a manner dependent on allele type.

  18. Characterization of a highly pathogenic avian influenza H5N1 virus isolated from an ostrich.

    PubMed

    Yang, Penghui; Dongmei; Wang, Cheng; Tang, Chong; Xing, Li; Luo, Deyan; Zhan, Zhongpeng; Duan, Yueqiang; Jia, Weihong; Peng, Daxin; Liu, Xiufan; Wang, Xiliang

    2010-06-11

    The continued spread of a highly pathogenic avian influenza (HPAI) H5N1 virus among poultry and wild birds has posed a potential threat to human public health. An influenza pandemic happens, when a new subtype that has not previously circulated in humans emerges. Almost all of the influenza pandemics in history have originated from avian influenza viruses (AIV). Birds are significant reservoirs of influenza viruses. In the present study, we performed a survey of avian influenza virus in ostriches and H5N1 virus (A/Ostrich/SuZhou/097/03, China097) was isolated. This H5N1 virus is highly pathogenic to both chickens and mice. It is also able to replicate in the lungs of, and to cause death in, BALB/c mice following intranasal administration. It forms plaques in chicken embryo fibroblast (CEF) cells in the absence of trypsin. The hemagglutinin (HA) gene of the virus is genetically similar to A/Goose/Guangdong/1/96(H5N1) and belongs to clade 0. The HA sequence contains multiple basic amino acids adjacent to the cleavage site, a motif associated with HPAI viruses. More importantly, the existence of H5N1 isolates in ostriches highlights the potential threat of wild bird infections to veterinary and public health. PMID:20497905

  19. Avian Influenza Biosecurity: Filling the Gaps with Non-Traditional Education

    ERIC Educational Resources Information Center

    Madsen, Jennifer; Tablante, Nathaniel

    2013-01-01

    Outbreaks of highly pathogenic avian influenza have become endemic, crippling trade and livelihood for many, and in rare cases, resulting in human fatalities. It is imperative that up-to-date education and training in accessible and interactive formats be available to key target audiences like poultry producers, backyard flock owners, and…

  20. 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...

  1. 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.

  2. Global avian influenza surveillance in wild birds: A strategy to capture viral diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) is a global threat to food animal production and distribution systems as well as human health. However, a sustained, comprehensive and coordinated global effort to monitor the continually changing genetic diversity of AI viruses (AIVs) circulating in nature is lacking. Two strai...

  3. Cross talk between animal and human influenza viruses.

    PubMed

    Ozawa, Makoto; Kawaoka, Yoshihiro

    2013-01-01

    Although outbreaks of highly pathogenic avian influenza in wild and domestic birds have been posing the threat of a new influenza pandemic for the past decade, the first pandemic of the twenty-first century came from swine viruses. This fact emphasizes the complexity of influenza viral ecology and the difficulty of predicting influenza viral dynamics. Complete control of influenza viruses seems impossible. However, we must minimize the impact of animal and human influenza outbreaks by learning lessons from past experiences and recognizing the current status. Here, we review the most recent influenza virology data in the veterinary field, including aspects of zoonotic agents and recent studies that assess the pandemic potential of H5N1 highly pathogenic avian influenza viruses.

  4. Frequently Asked Questions on Human Infection Caused by the Avian Influenza A (H7N9) Virus

    MedlinePlus

    ... to eat meat/animal products, for example, poultry, eggs, and pork? Because influenza viruses are inactivated by ... not be eaten. 10. How can meat and eggs be safely prepared? Always keep raw meat and ...

  5. Single assay for simultaneous detection and differential identification of human and avian influenza virus types, subtypes, and emergent variants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rapid and accurate detection, identification and genetic characterization are essential for effective surveillance and epidemiological tracking of influenza viruses. This report describes applications of a resequencing pathogen microarray (RPM) assay that is capable of simultaneous sequencing of su...

  6. The use of nonhuman primates in research on seasonal, pandemic and avian influenza, 1893-2014.

    PubMed

    Davis, A Sally; Taubenberger, Jeffery K; Bray, Mike

    2015-05-01

    Attempts to reproduce the features of human influenza in laboratory animals date from the early 1890s, when Richard Pfeiffer inoculated apes with bacteria recovered from influenza patients and produced a mild respiratory illness. Numerous studies employing nonhuman primates (NHPs) were performed during the 1918 pandemic and the following decade. Most used bacterial preparations to infect animals, but some sought a filterable agent for the disease. Since the viral etiology of influenza was established in the early 1930s, studies in NHPs have been supplemented by a much larger number of experiments in mice, ferrets and human volunteers. However, the emergence of a novel swine-origin H1N1 influenza virus in 1976 and the highly pathogenic H5N1 avian influenza virus in 1997 stimulated an increase in NHP research, because these agents are difficult to study in naturally infected patients and cannot be administered to human volunteers. In this paper, we review the published literature on the use of NHPs in influenza research from 1893 through the end of 2014. The first section summarizes observational studies of naturally occurring influenza-like syndromes in wild and captive primates, including serologic investigations. The second provides a chronological account of experimental infections of NHPs, beginning with Pfeiffer's study and covering all published research on seasonal and pandemic influenza viruses, including vaccine and antiviral drug testing. The third section reviews experimental infections of NHPs with avian influenza viruses that have caused disease in humans since 1997. The paper concludes with suggestions for further studies to more clearly define and optimize the role of NHPs as experimental animals for influenza research. PMID:25746173

  7. The use of nonhuman primates in research on seasonal, pandemic and avian influenza, 1893–2014

    PubMed Central

    Davis, A. Sally; Taubenberger, Jeffery K.; Bray, Mike

    2015-01-01

    Attempts to reproduce the features of human influenza in laboratory animals date from the early 1890s, when Richard Pfeiffer inoculated apes with bacteria recovered from influenza patients and produced a mild respiratory illness. Numerous studies employing nonhuman primates (NHPs) were performed during the 1918 pandemic and the following decade. Most used bacterial preparations to infect animals, but some sought a filterable agent for the disease. Since the viral etiology of influenza was established in the early 1930s, studies in NHPs have been supplemented by a much larger number of experiments in mice, ferrets and human volunteers. However, the emergence of a novel swine-origin H1N1 influenza virus in 1976 and the highly pathogenic H5N1 avian influenza virus in 1997 stimulated an increase in NHP research, because these agents are difficult to study in naturally infected patients and cannot be administered to human volunteers. In this paper, we review the published literature on the use of NHPs in influenza research from 1893 through the end of 2014. The first section summarizes observational studies of naturally occurring influenza-like syndromes in wild and captive primates, including serologic investigations. The second provides a chronological account of experimental infections of NHPs, beginning with Pfeiffer’s study and covering all published research on seasonal and pandemic influenza viruses, including vaccine and antiviral drug testing. The third section reviews experimental infections of NHPs with avian influenza viruses that have caused disease in humans since 1997. The paper concludes with suggestions for further studies to more clearly define and optimize the role of NHPs as experimental animals for influenza research. PMID:25746173

  8. The use of nonhuman primates in research on seasonal, pandemic and avian influenza, 1893-2014.

    PubMed

    Davis, A Sally; Taubenberger, Jeffery K; Bray, Mike

    2015-05-01

    Attempts to reproduce the features of human influenza in laboratory animals date from the early 1890s, when Richard Pfeiffer inoculated apes with bacteria recovered from influenza patients and produced a mild respiratory illness. Numerous studies employing nonhuman primates (NHPs) were performed during the 1918 pandemic and the following decade. Most used bacterial preparations to infect animals, but some sought a filterable agent for the disease. Since the viral etiology of influenza was established in the early 1930s, studies in NHPs have been supplemented by a much larger number of experiments in mice, ferrets and human volunteers. However, the emergence of a novel swine-origin H1N1 influenza virus in 1976 and the highly pathogenic H5N1 avian influenza virus in 1997 stimulated an increase in NHP research, because these agents are difficult to study in naturally infected patients and cannot be administered to human volunteers. In this paper, we review the published literature on the use of NHPs in influenza research from 1893 through the end of 2014. The first section summarizes observational studies of naturally occurring influenza-like syndromes in wild and captive primates, including serologic investigations. The second provides a chronological account of experimental infections of NHPs, beginning with Pfeiffer's study and covering all published research on seasonal and pandemic influenza viruses, including vaccine and antiviral drug testing. The third section reviews experimental infections of NHPs with avian influenza viruses that have caused disease in humans since 1997. The paper concludes with suggestions for further studies to more clearly define and optimize the role of NHPs as experimental animals for influenza research.

  9. 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.

  10. The pandemic potential of avian influenza A(H7N9) virus: a review.

    PubMed

    Tanner, W D; Toth, D J A; Gundlapalli, A V

    2015-12-01

    In March 2013 the first cases of human avian influenza A(H7N9) were reported to the World Health Organization. Since that time, over 650 cases have been reported. Infections are associated with considerable morbidity and mortality, particularly within certain demographic groups. This rapid increase in cases over a brief time period is alarming and has raised concerns about the pandemic potential of the H7N9 virus. Three major factors influence the pandemic potential of an influenza virus: (1) its ability to cause human disease, (2) the immunity of the population to the virus, and (3) the transmission potential of the virus. This paper reviews what is currently known about each of these factors with respect to avian influenza A(H7N9). Currently, sustained human-to-human transmission of H7N9 has not been reported; however, population immunity to the virus is considered very low, and the virus has significant ability to cause human disease. Several statistical and geographical modelling studies have estimated and predicted the spread of the H7N9 virus in humans and avian species, and some have identified potential risk factors associated with disease transmission. Additionally, assessment tools have been developed to evaluate the pandemic potential of H7N9 and other influenza viruses. These tools could also hypothetically be used to monitor changes in the pandemic potential of a particular virus over time.

  11. The Irrationality of GOF Avian Influenza Virus Research

    PubMed Central

    Wain-Hobson, Simon

    2014-01-01

    The last two and a half years have witnessed a curious debate in virology characterized by a remarkable lack of discussion. It goes by the misleading epithet “gain of function” (GOF) influenza virus research, or simply GOF. As will be seen, there is nothing good to be gained. The controversial experiments confer aerosol transmission on avian influenza virus strains that can infect humans, but which are not naturally transmitted between humans. Some of the newer strains are clearly highly pathogenic for man. It will be shown here that the benefits of the work are erroneous and overstated while the risk of an accident is finite, if small. The consequence of any accident would be anywhere from a handful of infections to a catastrophic pandemic. There has been a single open international meeting in this period, which is surprising given that openness and discussion are essential to good science. Despite US and EU government funding, no risk–benefit analysis has been published, which again is surprising. This research can be duplicated readily in many labs and requires little high tech. It falls under the definition of DURC without the slightest shadow of a doubt and constitutes the most important challenge facing contemporary biology. PMID:25077136

  12. Development of a reverse transcription loop-mediated isothermal amplification assay for the rapid diagnosis of avian influenza A (H7N9) virus infection.

    PubMed

    Nakauchi, Mina; Takayama, Ikuyo; Takahashi, Hitoshi; Tashiro, Masato; Kageyama, Tsutomu

    2014-08-01

    A genetic diagnosis system for detecting avian influenza A (H7N9) virus infection using reverse transcription-loop-mediated isothermal amplification (RT-LAMP) technology was developed. The RT-LAMP assay showed no cross-reactivity with seasonal influenza A (H3N2 and H1N1pdm09) or influenza B viruses circulating in humans or with avian influenza A (H5N1) viruses. The sensitivity of the RT-LAMP assay was 42.47 copies/reaction. Considering the high specificity and sensitivity of the assay for detecting the avian influenza A (H7N9) virus and that the reaction was completed within 30 min, the RT-LAMP assay developed in this study is a promising rapid diagnostic tool for avian influenza A (H7N9) virus infection.

  13. Respiratory transmission of an avian H3N8 influenza virus isolated from a harbour seal

    PubMed Central

    Karlsson, Erik A.; Ip, Hon S.; Hall, Jeffrey S.; Yoon, Sun Woo; Johnson, Jordan; Beck, Melinda A.; Webby, Richard J.; Schultz-Cherry, Stacey

    2016-01-01

    The ongoing human H7N9 influenza infections highlight the threat of emerging avian influenza viruses. In 2011, an avian H3N8 influenza virus isolated from moribund New England harbour seals was shown to have naturally acquired mutations known to increase the transmissibility of highly pathogenic H5N1 influenza viruses. To elucidate the potential human health threat, here we evaluate a panel of avian H3N8 viruses and find that the harbour seal virus displays increased affinity for mammalian receptors, transmits via respiratory droplets in ferrets and replicates in human lung cells. Analysis of a panel of human sera for H3N8 neutralizing antibodies suggests that there is no population-wide immunity to these viruses. The prevalence of H3N8 viruses in birds and multiple mammalian species including recent isolations from pigs and evidence that it was a past human pandemic virus make the need for surveillance and risk analysis of these viruses of public health importance. PMID:25183346

  14. Respiratory transmission of an avian H3N8 influenza virus isolated from a harbour seal

    USGS Publications Warehouse

    Karlsson, Erik A.; Ip, Hon S.; Hall, Jeffrey S.; Yoon, Sun W.; Johnson, Jordan; Beck, Melinda A.; Webby, Richard J.; Schultz-Cherry, Stacey

    2014-01-01

    The ongoing human H7N9 influenza infections highlight the threat of emerging avian influenza viruses. In 2011, an avian H3N8 influenza virus isolated from moribund New England harbour seals was shown to have naturally acquired mutations known to increase the transmissibility of highly pathogenic H5N1 influenza viruses. To elucidate the potential human health threat, here we evaluate a panel of avian H3N8 viruses and find that the harbour seal virus displays increased affinity for mammalian receptors, transmits via respiratory droplets in ferrets and replicates in human lung cells. Analysis of a panel of human sera for H3N8 neutralizing antibodies suggests that there is no population-wide immunity to these viruses. The prevalence of H3N8 viruses in birds and multiple mammalian species including recent isolations from pigs and evidence that it was a past human pandemic virus make the need for surveillance and risk analysis of these viruses of public health importance.

  15. Construction and cellular immune response induction of HA-based alphavirus replicon vaccines against human-avian influenza (H5N1).

    PubMed

    Yang, Shi-gui; Wo, Jian-er; Li, Min-wei; Mi, Fen-fang; Yu, Cheng-bo; Lv, Guo-liang; Cao, Hong-Cui; Lu, Hai-feng; Wang, Bao-hong; Zhu, Hanping; Li, Lan-Juan

    2009-12-01

    Several approaches are being taken worldwide to develop vaccines against H5N1 viruses; most of them, however, pose both practical and immunological challenges. One potential strategy for improving the immunogenicity of vaccines involves the use of alphavirus replicons and VP22, a herpes simplex type 1 (HSV-1) protein. In this study, we analysed the antigenic peptides and homogeneity of the HA sequences (human isolates of the H5N1 subtype, from 1997 to 2003) and explored a novel alphavirus replicon system of VP22 fused with HA, to assess whether the immunogenicity of an HA-based replicon vaccine could be induced and augmented via fusion with VP22. Further, replicon particles expressing VP22, and enhanced green fluorescent protein (EGFP) were individually used as controls. Cellular immune responses in mice immunised with replicons were evaluated by identifying specific intracellular cytokine production with flow cytometry (FCM). Animal-based experimentation indicated that both the IL-4 expression of CD4(+) T cells and the IFN-gamma expression of CD8(+) T cells were significantly increased in mice immunised with VPR-HA and VPR-VP22/HA. A dose titration effect vis-à-vis both IL-4 expression and IFN-gamma expression were observed in VPR-HA- and VPR-VP22/HA-vaccinated mice. Our results revealed that both VPR-VP22/HA and VPR-HA replicon particles presented a promising approach for developing vaccines against human-avian influenza, and VP22 could enhance the immunogenicity of the HA antigens to which it is fused.

  16. Control strategies for highly pathogenic avian influenza: a global perspective.

    PubMed

    Lubroth, J

    2007-01-01

    Comprehensive programmes for the prevention, detection and control of highly pathogenic avian influenza (HPAI) require a national dimension and relevant national legislation in which veterinary services can conduct surveillance, competent diagnosis and rapid response. Avian influenza was controlled and prevented by vaccination long before the current H5N1 crisis. The use of vaccine cannot be separated from other essential elements of a vaccination campaign, which include education in poultry production practices, such as hygiene, all in-all out production concepts, separation of species, biosecurity (bio-exclusion to keep the disease out and biocontainment to keep the disease from spreading once suspected or detected), competence in giving the vaccine and the role of vaccination teams, post-vaccination monitoring to ensure efficacy and to detect the circulation of wild-type virus, surveillance and buffer zones in outbreak areas, and performance indicators to determine when vaccination can cease. Reporting of disease can be improved through well-structured, adequately financed veterinary services and also by fair compensation for producers who suffer financial loss. A rapid response to suspected cases of HPAI should be ensured in simulation exercises involving various sectors of the food production and marketing chain, policy-makers, official veterinary structures and other government personnel. As for other transboundary animal diseases, national approaches must be part of a regional strategy and regional networks for cooperation and information sharing, which in turn reflect global policies and international standards, such as the quality of vaccines, reporting obligations, humane interventions, cleaning and disinfection methods, restocking times, monitoring and safe trade.

  17. Within-host variation of avian influenza viruses

    PubMed Central

    Iqbal, Munir; Xiao, Hiaxia; Baillie, Greg; Warry, Andrew; Essen, Steve C.; Londt, Brandon; Brookes, Sharon M.; Brown, Ian H.; McCauley, John W.

    2009-01-01

    The emergence and spread of H5N1 avian influenza viruses from Asia through to Europe and Africa pose a significant animal disease problem and have raised concerns that the virus may pose a pandemic threat to humans. The epizootological factors that have influenced the wide distribution of the virus are complex, and the variety of viruses currently circulating reflects these factors. Sequence analysis of the virus genes sheds light on the H5N1 virus evolution during its emergence and spread, but the degree of virus variation at the level of an individual infected bird has been described in only a few studies. Here, we describe some results of a study in which turkeys, ducks and chickens were infected with either one of two H5N1 or one of three H7N1 viruses, and the degree of sequence variation within an individual infected avian host was examined. We developed ‘deep amplicon’ sequence analysis for this work, and the methods and results provide a background framework for application to disease outbreaks in the field. PMID:19687042

  18. 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.

  19. Rapidly Expanding Range of Highly Pathogenic Avian Influenza Viruses.

    PubMed

    Hall, Jeffrey S; Dusek, Robert J; Spackman, Erica

    2015-07-01

    The movement of highly pathogenic avian influenza (H5N8) virus across Eurasia and into North America and the virus' propensity to reassort with co-circulating low pathogenicity viruses raise concerns among poultry producers, wildlife biologists, aviculturists, and public health personnel worldwide. Surveillance, modeling, and experimental research will provide the knowledge required for intelligent policy and management decisions.

  20. Rapidly Expanding Range of Highly Pathogenic Avian Influenza Viruses

    PubMed Central

    Dusek, Robert J.; Spackman, Erica

    2015-01-01

    The movement of highly pathogenic avian influenza (H5N8) virus across Eurasia and into North America and the virus’ propensity to reassort with co-circulating low pathogenicity viruses raise concerns among poultry producers, wildlife biologists, aviculturists, and public health personnel worldwide. Surveillance, modeling, and experimental research will provide the knowledge required for intelligent policy and management decisions. PMID:26079209

  1. Rapidly expanding range of highly pathogenic avian influenza viruses

    USGS Publications Warehouse

    Hall, Jeffrey S.; Dusek, Robert J.; Spackman, Erica

    2015-01-01

    The movement of highly pathogenic avian influenza (H5N8) virus across Eurasia and into North America and the virus’ propensity to reassort with co-circulating low pathogenicity viruses raise concerns among poultry producers, wildlife biologists, aviculturists, and public health personnel worldwide. Surveillance, modeling, and experimental research will provide the knowledge required for intelligent policy and management decisions.

  2. Avian influenza: worldwide situation and effectiveness of current vaccines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The H5N1 high pathogenicity avian influenza (HPAI) virus emerged in China during 1996 and has spread to infect poultry and/or wild birds in 63 countries during the past 18 years. The majority of the recent outbreaks of H5N2 HPAI have occurred in Indonesia, Egypt, Vietnam, and Bangladesh, in decreasi...

  3. Prevention and control of avian influenza in Asia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The H5N1 high pathogenicity avian influenza (HPAI) virus emerged in China during 1996 and has spread to infect poultry and/or wild birds in 62 countries during the past 15 years. For 2011-2012, 19 countries reported outbreaks of H5N1 in domestic poultry, wild birds or both. The majority of the outbr...

  4. Highly pathogenic avian influenza virus among wild birds in Mongolia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The central Asian country of Mongolia supports large populations of migratory water birds that migrate across much of Asia where highly pathogenic avian influenza (HPAI) virus subtype H5N1 is endemic. This, together with the near absence of domestic poultry, makes Mongolia an ideal location to unde...

  5. Highly pathogenic avian influenza challenge studies in waterfowl

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Waterfowl are the natural hosts of avian influenza (AI) virus. The majority of AI viruses are classified as low pathogenicity (LP) based on their virulence in chickens, which are the reference species for pathotype testing and can be any of the 16 hemagglutinin subtypes (H1-16). Circulation of H5 ...

  6. Rapidly expanding range of highly pathogenic avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The recent introduction of highly pathogenic avian influenza virus (HPAIV) H5N8 into Europe and North America poses significant risks to poultry industries and wildlife populations and warrants continued and heightened vigilance. First discovered in South Korean poultry and wild birds in early 2014...

  7. 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

  8. Persistence of Highly Pathogenic Avian Influenza Viruses in Natural Ecosystems

    PubMed Central

    Feare, Chris J.; Renaud, François; Thomas, Frédéric; Gauthier-Clerc, Michel

    2010-01-01

    Understanding of ecologic factors favoring emergence and maintenance of highly pathogenic avian influenza (HPAI) viruses is limited. Although low pathogenic avian influenza viruses persist and evolve in wild populations, HPAI viruses evolve in domestic birds and cause economically serious epizootics that only occasionally infect wild populations. We propose that evolutionary ecology considerations can explain this apparent paradox. Host structure and transmission possibilities differ considerably between wild and domestic birds and are likely to be major determinants of virulence. Because viral fitness is highly dependent on host survival and dispersal in nature, virulent forms are unlikely to persist in wild populations if they kill hosts quickly or affect predation risk or migratory performance. Interhost transmission in water has evolved in low pathogenic influenza viruses in wild waterfowl populations. However, oropharyngeal shedding and transmission by aerosols appear more efficient for HPAI viruses among domestic birds. PMID:20587174

  9. Multiplex electrical detection of avian influenza and human immunodeficiency virus with an underlap-embedded silicon nanowire field-effect transistor.

    PubMed

    Kim, Jee-Yeon; Ahn, Jae-Hyuk; Moon, Dong-Il; Park, Tae Jung; Lee, Sang Yup; Choi, Yang-Kyu

    2014-05-15

    The label-free electrical detection of the binding of antibodies and antigens of avian influenza (AI) and human immunodeficiency (HIV) viruses is demonstrated through an underlap-embedded silicon (Si) nanowire field-effect transistor. The proposed sensor was fabricated on a silicon bulk wafer by a top-down process. Specifically, a Si nanowire was fabricated by a combined isotropic and anisotropic patterning technique, which is one route plasma etching process. The sensor was fabricated by a self-aligned process to the gate with tilted implantation, and it allows precise control of the underlap region. This was problematic in earlier underlap field-effect transistors fabricated by a conventional gate-last process. As a sensing metric to detect the binding of a targeted antibody, the transfer characteristic change was traced. Before and after differences between the antibody binding results were caused by changes in the channel potential on the underlap region due to the charge effect arising from the biomolecules; this is also supported by a simulation. Furthermore, the multiplex detection of AI and HIV is demonstrated, showing distinctive selectivity in each case. Thus, the proposed device has inherent benefits for the label-free, electrical, and multiplex detection of biomolecules. Moreover, its processes are compatible with commercialized technology presently used to fabricate semiconductor devices. This advantage is attractive for those involved in the construction of a point-of-care testing (POCT) system on a chip involving simple, low-cost and low-risk fabrication processes of novel structures and materials.

  10. Perceptions on the risk communication strategy during the 2013 avian influenza A/H7N9 outbreak in humans in China: a focus group study

    PubMed Central

    Li, Richun; Xie, Ruiqian; Yang, Chong

    2016-01-01

    Objective To identify the general public’s perceptions of the overall risk communication strategy carried out by Chinese public health agencies during the first wave of avian influenza A(H7N9) outbreak in humans in 2013. Methods Participants were recruited from communities in Beijing, Lanzhou and Hangzhou, China in May and June 2013 by convenience sampling. Demographics and other relevant information were collected using a self-administered questionnaire. Focus group interviews were conducted using a set of nine pre-developed questions and a tested moderator guide. The interviews were audio recorded and were transcribed verbatim. The constant comparative method was used to identify trends and themes. Results A total of nine focus group interviews, with 94 participants recruited from nine communities, were conducted. Most participants received H7N9 information via television and the Internet. Most the participants appreciated the transparency and timeliness of the information released by the government. They expressed a sense of trust in the recommended public health advice and followed most of them. The participants suggested that the government release more information about clinical treatment outcomes, have more specific health recommendations that are practical to their settings and expand the use of new media channels for risk communication. Conclusion The public perceived the overall risk communication strategy by the Chinese public health agencies as effective, though the moderator had a governmental agency title that might have biased the results. There is a need to expand the use of social media for risk communication in the future. PMID:27757257

  11. Epidemiology of avian influenza in wild aquatic birds in a biosecurity hotspot, North Queensland, Australia.

    PubMed

    Hoque, Md Ahasanul; Burgess, Graham William; Cheam, Ai Lee; Skerratt, Lee Francis

    2015-01-01

    Migratory birds may introduce highly pathogenic H5N1 avian influenza from Southeast Asia into Australia via North Queensland, a key stopover along the East Asian-Australasian Flyway, with severe consequences for trade and human health. A 3-year repeated cross sectional study on the epidemiology of avian influenza in Australian nomadic wild aquatic birds was conducted in this potential biosecurity hotspot using molecular and serological techniques. Avian influenza virus subtypes H6 and H9 were commonly present in the studied population. It is likely that one of the H6 viruses was newly introduced through migratory birds confirming the perceived biosecurity risk. The matrix gene of another H6 virus was similar to the Australian H7 subtypes, which suggests the reassortment of a previously introduced H6 and local viruses. Similarly, a H9 subtype had a matrix gene similar to that found in Asian H9 viruses suggesting reassortment of viruses originated from Australia and Asia. Whilst H5N1 was not found, the serological study demonstrated a constant circulation of the H5 subtype in the sampled birds. The odds of being reactive for avian influenza viral antibodies were 13.1(95% CI: 5.9-28.9) for Pacific Black Ducks over Plumed Whistling Ducks, highlighting that some species of waterfowl pose a greater biosecurity risk. Antibody titres were slightly higher during warm wet compared with warm dry weather. Routine surveillance programmes should be established to monitor the introduction of avian influenza viruses from Asia and the interactions of the introduced viruses with resident viruses in order to better detect emerging pathogens in aquatic birds of North Queensland. Surveillance should be targeted towards highly susceptible species such as the Pacific Black Duck and carried out during favourable environmental conditions for viral transmission such as the wet season in northern Australia.

  12. Isolation of a novel H3N2 influenza virus containing a gene of H9N2 avian influenza in a dog in South Korea in 2015.

    PubMed

    Lee, In Hong; Le, Tran Bac; Kim, Hyun Soo; Seo, Sang Heui

    2016-02-01

    We isolated a serotype H3N2 influenza virus from a dog with severe respiratory distress in an animal clinic in South Korea in 2015 and characterized the sequences of its eight genes. The following seven genes were derived from canine influenza virus: PB2, PB1, HA, NP, NA, M, and NS. However, the PA gene was derived from avian H9N2 influenza virus that is circulating in poultry in Korea. These findings suggest that the continued surveillance of the influenza virus in dogs is warranted because humans have close contact with dogs, which may promote viral transmission.

  13. The hemagglutinin structure of an avian H1N1 influenza A virus

    SciTech Connect

    Lin, Tianwei; Wang, Gengyan; Li, Anzhang; Zhang, Qian; Wu, Caiming; Zhang, Rongfu; Cai, Qixu; Song, Wenjun; Yuen, Kwok-Yung

    2009-09-15

    The interaction between hemagglutinin (HA) and receptors is a kernel in the study of evolution and host adaptation of H1N1 influenza A viruses. The notion that the avian HA is associated with preferential specificity for receptors with Sia{alpha}2,3Gal glycosidic linkage over those with Sia{alpha}2,6Gal linkage is not all consistent with the available data on H1N1 viruses. By x-ray crystallography, the HA structure of an avian H1N1 influenza A virus, as well as its complexes with the receptor analogs, was determined. The structures revealed no preferential binding of avian receptor analogs over that of the human analog, suggesting that the HA/receptor binding might not be as stringent as is commonly believed in determining the host receptor preference for some subtypes of influenza viruses, such as the H1N1 viruses. The structure also showed difference in glycosylation despite the preservation of related sequences, which may partly contribute to the difference between structures of human and avian origin.

  14. Live poultry market workers are susceptible to both avian and swine influenza viruses, Guangdong Province, China.

    PubMed

    Chen, Jidang; Ma, Jun; White, Sarah K; Cao, Zhenpeng; Zhen, Yun; He, Shuyi; Zhu, Wanjun; Ke, Changwen; Zhang, Yongbiao; Su, Shuo; Zhang, Guihong

    2015-12-31

    Guangdong Province is recognized for dense populations of humans, pigs, poultry and pets. In order to evaluate the threat of viral infection faced by those working with animals, a cross-sectional, sero-epidemiological study was conducted in Guangdong between December 2013 and January 2014. Individuals working with swine, at poultry farms, or live poultry markets (LPM), and veterinarians, and controls not exposed to animals were enrolled in this study and 11 (4 human, 3 swine, 3 avian, and 1 canine) influenza A viruses were used in hemagglutination inhibition (HI) assays (7 strains) and the cross-reactivity test (9 strains) in which 5 strains were used in both tests. Univariate analysis was performed to identify which variables were significantly associated with seropositivity. Odds ratios (OR) revealed that swine workers had a significantly higher risk of elevated antibodies against A/swine/Guangdong/L6/2009(H1N1), a classical swine virus, and A/swine/Guangdong/SS1/2012(H1N1), a Eurasian avian-like swine virus than non-exposed controls. Poultry farm workers were at a higher risk of infection with avian influenza H7N9 and H9N2. LPM workers were at a higher risk of infection with 3 subtypes of avian influenza, H5N1, H7N9, and H9N2. Interestingly, the OR also indicated that LPM workers were at risk of H1N1 swine influenza virus infection, perhaps due to the presence of pigs in the LPM. While partial confounding by cross-reactive antibodies against human viruses or vaccines cannot be ruled out, our data suggests that animal exposed people as are more likely to have antibodies against animal influenza viruses.

  15. Live poultry market workers are susceptible to both avian and swine influenza viruses, Guangdong Province, China.

    PubMed

    Chen, Jidang; Ma, Jun; White, Sarah K; Cao, Zhenpeng; Zhen, Yun; He, Shuyi; Zhu, Wanjun; Ke, Changwen; Zhang, Yongbiao; Su, Shuo; Zhang, Guihong

    2015-12-31

    Guangdong Province is recognized for dense populations of humans, pigs, poultry and pets. In order to evaluate the threat of viral infection faced by those working with animals, a cross-sectional, sero-epidemiological study was conducted in Guangdong between December 2013 and January 2014. Individuals working with swine, at poultry farms, or live poultry markets (LPM), and veterinarians, and controls not exposed to animals were enrolled in this study and 11 (4 human, 3 swine, 3 avian, and 1 canine) influenza A viruses were used in hemagglutination inhibition (HI) assays (7 strains) and the cross-reactivity test (9 strains) in which 5 strains were used in both tests. Univariate analysis was performed to identify which variables were significantly associated with seropositivity. Odds ratios (OR) revealed that swine workers had a significantly higher risk of elevated antibodies against A/swine/Guangdong/L6/2009(H1N1), a classical swine virus, and A/swine/Guangdong/SS1/2012(H1N1), a Eurasian avian-like swine virus than non-exposed controls. Poultry farm workers were at a higher risk of infection with avian influenza H7N9 and H9N2. LPM workers were at a higher risk of infection with 3 subtypes of avian influenza, H5N1, H7N9, and H9N2. Interestingly, the OR also indicated that LPM workers were at risk of H1N1 swine influenza virus infection, perhaps due to the presence of pigs in the LPM. While partial confounding by cross-reactive antibodies against human viruses or vaccines cannot be ruled out, our data suggests that animal exposed people as are more likely to have antibodies against animal influenza viruses. PMID:26476563

  16. 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

    2016-01-01

    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

  17. Circulating avian influenza viruses closely related to the 1918 virus have pandemic potential.

    PubMed

    Watanabe, Tokiko; Zhong, Gongxun; Russell, Colin A; Nakajima, Noriko; Hatta, Masato; Hanson, Anthony; McBride, Ryan; Burke, David F; Takahashi, Kenta; Fukuyama, Satoshi; Tomita, Yuriko; Maher, Eileen A; Watanabe, Shinji; Imai, Masaki; Neumann, Gabriele; Hasegawa, Hideki; Paulson, James C; Smith, Derek J; Kawaoka, Yoshihiro

    2014-06-11

    Wild birds harbor a large gene pool of influenza A viruses that have the potential to cause influenza pandemics. Foreseeing and understanding this potential is important for effective surveillance. Our phylogenetic and geographic analyses revealed the global prevalence of avian influenza virus genes whose proteins differ only a few amino acids from the 1918 pandemic influenza virus, suggesting that 1918-like pandemic viruses may emerge in the future. To assess this risk, we generated and characterized a virus composed of avian influenza viral segments with high homology to the 1918 virus. This virus exhibited pathogenicity in mice and ferrets higher than that in an authentic avian influenza virus. Further, acquisition of seven amino acid substitutions in the viral polymerases and the hemagglutinin surface glycoprotein conferred respiratory droplet transmission to the 1918-like avian virus in ferrets, demonstrating that contemporary avian influenza viruses with 1918 virus-like proteins may have pandemic potential. PMID:24922572

  18. Circulating avian influenza viruses closely related to the 1918 virus have pandemic potential

    PubMed Central

    Watanabe, Tokiko; Zhong, Gongxun; Russell, Colin A.; Nakajima, Noriko; Hatta, Masato; Hanson, Anthony; McBride, Ryan; Burke, David F.; Takahashi, Kenta; Fukuyama, Satoshi; Tomita, Yuriko; Maher, Eileen A.; Watanabe, Shinji; Imai, Masaki; Neumann, Gabriele; Hasegawa, Hideki; Paulson, James C.; Smith, Derek J.; Kawaoka, Yoshihiro

    2014-01-01

    Summary Wild birds harbor a large gene pool of influenza A viruses that have the potential to cause influenza pandemics. Foreseeing and understanding this potential is important for effective surveillance. Our phylogenetic and geographic analyses revealed the global prevalence of avian influenza virus genes whose proteins differ only a few amino acids from the 1918 pandemic influenza virus, suggesting that 1918-like pandemic viruses may emerge in the future. To assess this risk, we generated and characterized a virus composed of avian influenza viral segments with high homology to the 1918 virus. This virus exhibited higher pathogenicity in mice and ferrets than an authentic avian influenza virus. Further, acquisition of seven amino acid substitutions in the viral polymerases and the hemagglutinin surface glycoprotein conferred respiratory droplet transmission to the 1918-like avian virus in ferrets, demonstrating that contemporary avian influenza viruses with 1918 virus-like proteins may have pandemic potential. PMID:24922572

  19. Human Influenza Virus Infections.

    PubMed

    Peteranderl, Christin; Herold, Susanne; Schmoldt, Carole

    2016-08-01

    Seasonal and pandemic influenza are the two faces of respiratory infections caused by influenza viruses in humans. As seasonal influenza occurs on an annual basis, the circulating virus strains are closely monitored and a yearly updated vaccination is provided, especially to identified risk populations. Nonetheless, influenza virus infection may result in pneumonia and acute respiratory failure, frequently complicated by bacterial coinfection. Pandemics are, in contrary, unexpected rare events related to the emergence of a reassorted human-pathogenic influenza A virus (IAV) strains that often causes increased morbidity and spreads extremely rapidly in the immunologically naive human population, with huge clinical and economic impact. Accordingly, particular efforts are made to advance our knowledge on the disease biology and pathology and recent studies have brought new insights into IAV adaptation mechanisms to the human host, as well as into the key players in disease pathogenesis on the host side. Current antiviral strategies are only efficient at the early stages of the disease and are challenged by the genomic instability of the virus, highlighting the need for novel antiviral therapies targeting the pulmonary host response to improve viral clearance, reduce the risk of bacterial coinfection, and prevent or attenuate acute lung injury. This review article summarizes our current knowledge on the molecular basis of influenza infection and disease progression, the key players in pathogenesis driving severe disease and progression to lung failure, as well as available and envisioned prevention and treatment strategies against influenza virus infection. PMID:27486731

  20. Human Influenza Virus Infections.

    PubMed

    Peteranderl, Christin; Herold, Susanne; Schmoldt, Carole

    2016-08-01

    Seasonal and pandemic influenza are the two faces of respiratory infections caused by influenza viruses in humans. As seasonal influenza occurs on an annual basis, the circulating virus strains are closely monitored and a yearly updated vaccination is provided, especially to identified risk populations. Nonetheless, influenza virus infection may result in pneumonia and acute respiratory failure, frequently complicated by bacterial coinfection. Pandemics are, in contrary, unexpected rare events related to the emergence of a reassorted human-pathogenic influenza A virus (IAV) strains that often causes increased morbidity and spreads extremely rapidly in the immunologically naive human population, with huge clinical and economic impact. Accordingly, particular efforts are made to advance our knowledge on the disease biology and pathology and recent studies have brought new insights into IAV adaptation mechanisms to the human host, as well as into the key players in disease pathogenesis on the host side. Current antiviral strategies are only efficient at the early stages of the disease and are challenged by the genomic instability of the virus, highlighting the need for novel antiviral therapies targeting the pulmonary host response to improve viral clearance, reduce the risk of bacterial coinfection, and prevent or attenuate acute lung injury. This review article summarizes our current knowledge on the molecular basis of influenza infection and disease progression, the key players in pathogenesis driving severe disease and progression to lung failure, as well as available and envisioned prevention and treatment strategies against influenza virus infection.

  1. Outbreak patterns of the novel avian influenza (H7N9)

    NASA Astrophysics Data System (ADS)

    Pan, Ya-Nan; Lou, Jing-Jing; Han, Xiao-Pu

    2014-05-01

    The attack of novel avian influenza (H7N9) in East China caused a serious health crisis and public panic. In this paper, we empirically analyze the onset patterns of human cases of the novel avian influenza and observe several spatial and temporal properties that are similar to other infectious diseases. More specifically, using the empirical analysis and modeling studies, we find that the spatio-temporal network that connects the cities with human cases along the order of outbreak timing emerges two-regime-power-law edge-length distribution, indicating the picture that several islands with higher and heterogeneous risk straggle in East China. The proposed method is applicable to the analysis of the spreading situation in the early stage of disease outbreak using quite limited dataset.

  2. Antigenic Characterization of H3 Subtypes of Avian Influenza A Viruses from North America

    PubMed Central

    Bailey, Elizabeth; Long, Li-Ping; Zhao, Nan; Hall, Jeffrey S.; Baroch, John A.; Nolting, Jacqueline; Senter, Lucy; Cunningham, Frederick L.; Pharr, G. Todd; Hanson, Larry; Slemons, Richard; DeLiberto, Thomas J.; Wan, Xiu-Feng

    2016-01-01

    SUMMARY Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts including avian, swine, equine, canine, and sea mammals. These H3 viruses are both antigenically and genetically diverse. Here we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performed on 37 H3 isolates of avian IAVs recovered from 2007 to 2011 using generated reference chicken sera. These isolates were recovered from samples taken in the Atlantic, Mississippi, Central, and Pacific waterfowl migration flyways. Antisera to all the tested H3 isolates cross-reacted with each other, and, to a lesser extent, with those to H3 canine and H3 equine IAVs. Antigenic cartography showed that the largest antigenic distance among the 37 avian IAVs is about 4 units, and each unit corresponds to a 2log2 difference in the HI titer. However, none of the tested H3 IAVs cross-reacted with ferret sera derived from contemporary swine and human IAVs. Our results showed that the H3 avian IAVs we tested lacked significant antigenic diversity, and these viruses were antigenically different from those circulating in swine and human populations. This suggests that H3 avian IAVs in North American waterfowl are antigenically relatively stable. PMID:27309078

  3. Antigenic Characterization of H3 Subtypes of Avian Influenza A Viruses from North America.

    PubMed

    Bailey, Elizabeth; Long, Li-Ping; Zhao, Nan; Hall, Jeffrey S; Baroch, John A; Nolting, Jacqueline; Senter, Lucy; Cunningham, Frederick L; Pharr, G Todd; Hanson, Larry; Slemons, Richard; DeLiberto, Thomas J; Wan, Xiu-Feng

    2016-05-01

    Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts, including avian, swine, equine, canine, and sea mammal species. These H3 viruses are both antigenically and genetically diverse. Here, we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performed on 37 H3 isolates of avian IAVs recovered from 2007 to 2011 using generated reference chicken sera. These isolates were recovered from samples taken in the Atlantic, Mississippi, Central, and Pacific waterfowl migration flyways. Antisera to all the tested H3 isolates cross-reacted with each other and, to a lesser extent, with those to H3 canine and H3 equine IAVs. Antigenic cartography showed that the largest antigenic distance among the 37 avian IAVs is about four units, and each unit corresponds to a 2 log 2 difference in the HI titer. However, none of the tested H3 IAVs cross-reacted with ferret sera derived from contemporary swine and human IAVs. Our results showed that the H3 avian IAVs we tested lacked significant antigenic diversity, and these viruses were antigenically different from those circulating in swine and human populations. This suggests that H3 avian IAVs in North American waterfowl are antigenically relatively stable.

  4. Antigenic characterization of H3 subtypes of avian influenza A viruses from North America

    USGS Publications Warehouse

    Bailey, Elizabeth; Long, Li-Pong; Zhao, Nan; Hall, Jeffrey S.; Baroch, John A; Nolting, Jaqueline; Senter, Lucy; Cunningham, Frederick L; Pharr, G Todd; Hanson, Larry; Slemons, Richard; DeLiberto, Thomas J.; Wan, Xiu-Feng

    2016-01-01

    Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts, including avian, swine, equine, canine, and sea mammal species. These H3 viruses are both antigenically and genetically diverse. Here, we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performed on 37 H3 isolates of avian IAVs recovered from 2007 to 2011 using generated reference chicken sera. These isolates were recovered from samples taken in the Atlantic, Mississippi, Central, and Pacific waterfowl migration flyways. Antisera to all the tested H3 isolates cross-reacted with each other and, to a lesser extent, with those to H3 canine and H3 equine IAVs. Antigenic cartography showed that the largest antigenic distance among the 37 avian IAVs is about four units, and each unit corresponds to a 2 log 2 difference in the HI titer. However, none of the tested H3 IAVs cross-reacted with ferret sera derived from contemporary swine and human IAVs. Our results showed that the H3 avian IAVs we tested lacked significant antigenic diversity, and these viruses were antigenically different from those circulating in swine and human populations. This suggests that H3 avian IAVs in North American waterfowl are antigenically relatively stable.

  5. Antigenic Characterization of H3 Subtypes of Avian Influenza A Viruses from North America.

    PubMed

    Bailey, Elizabeth; Long, Li-Ping; Zhao, Nan; Hall, Jeffrey S; Baroch, John A; Nolting, Jacqueline; Senter, Lucy; Cunningham, Frederick L; Pharr, G Todd; Hanson, Larry; Slemons, Richard; DeLiberto, Thomas J; Wan, Xiu-Feng

    2016-05-01

    Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts, including avian, swine, equine, canine, and sea mammal species. These H3 viruses are both antigenically and genetically diverse. Here, we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performed on 37 H3 isolates of avian IAVs recovered from 2007 to 2011 using generated reference chicken sera. These isolates were recovered from samples taken in the Atlantic, Mississippi, Central, and Pacific waterfowl migration flyways. Antisera to all the tested H3 isolates cross-reacted with each other and, to a lesser extent, with those to H3 canine and H3 equine IAVs. Antigenic cartography showed that the largest antigenic distance among the 37 avian IAVs is about four units, and each unit corresponds to a 2 log 2 difference in the HI titer. However, none of the tested H3 IAVs cross-reacted with ferret sera derived from contemporary swine and human IAVs. Our results showed that the H3 avian IAVs we tested lacked significant antigenic diversity, and these viruses were antigenically different from those circulating in swine and human populations. This suggests that H3 avian IAVs in North American waterfowl are antigenically relatively stable. PMID:27309078

  6. Identification of viral epitopes recognized on the hemagglutinin protein of the H7N9 avian influenza virus involved with virus neutralization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In March of 2013, the first cases of H7N9 influenza were reported in humans in China, and shortly thereafter the virus was confirmed from poultry in live bird markets. Since that time the virus has persisted in both human and avian populations. The genetic composition of these H7N9 influenza virus...

  7. Identification of viral epitopes recognized by the immune system following vaccination and challenge with the H7N9 avian influenza virus from China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In March of 2013, the first cases of H7N9 influenza were reported in humans in China, and shortly thereafter the virus was confirmed from poultry in live bird markets. Since that time the virus has persisted in both human and avian populations. The genetic composition of these H7N9 influenza virus...

  8. 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.

  9. Genetic variation of the hemagglutinin of avian influenza virus H9N2.

    PubMed

    Song, Xiao-feng; Han, Ping; Chen, Yi-Ping Phoebe

    2011-05-01

    Avian influenza virus H9N2 has become the dominant subtype of influenza which is endemic in poultry. The hemagglutinin, one of eight protein-coding genes, plays an important role during the early stage of infection. The adaptive evolution and the positively selected sites of the HA (the glycoprotein molecule) of H9N2 subtype viruses were investigated. Investigating 68 hemagglutinin H9N2 avian influenza virus isolates in China and phylogenetic analysis, it was necessary that these isolates were distributed geographically from 1994, and were all derived from the Eurasian lineage. H9N2 avian influenza virus isolates from domestic poultry in China were distinct phylogenetically from those isolated in Hong Kong, including viruses which had infected humans. Seven amino acid substitutions (2T, 3T, 14T, 165D, 197A, 233Q, 380R) were identified in the HA possibly due to positive selection pressure. Apart from the 380R site, the other positively selected sites detected were all located near the receptor-binding site of the HA1 strain. Based on epidemiological and phylogenetics analysis, the H9N2 epidemic in China was divided into three groups: the 1994-1997 group, the 1998-1999 group, and the 2000-2007 group. By investigating these three groups using the maximum likelihood estimation method, there were more positive selective sites in the 1994-1997 and 1998-1999 epidemic group than the 2000-2007 groups. This indicates that those detected selected sites are changed during different epidemic periods and the evolution of H9N2 is currently slow. The antigenic determinant or other key functional amino acid sites should be of concern because their adjacent sites have been under positive selection pressure. The results provide further evidence that the pathogenic changes in the H9N2 subtype are due mainly to re-assortment with other highly pathogenic avian influenza viruses.

  10. Genotypic diversity of H5N1 highly pathogenic avian influenza viruses.

    PubMed

    Zhao, Zi-Ming; Shortridge, Kennedy F; Garcia, Maricarmen; Guan, Yi; Wan, Xiu-Feng

    2008-09-01

    Besides enormous economic losses to the poultry industry, recent H5N1 highly pathogenic avian influenza viruses (HPAIVs) originating in eastern Asia have posed serious threats to public health. Up to April 17, 2008, 381 human cases had been confirmed with a mortality of more than 60 %. Here, we attempt to identify potential progenitor genes for H5N1 HPAIVs since their first recognition in 1996; most were detected in the Eurasian landmass before 1996. Combinations among these progenitor genes generated at least 21 reassortants (named H5N1 progenitor reassortant, H5N1-PR1-21). H5N1-PR1 includes A/Goose/Guangdong/1/1996(H5N1). Only reassortants H5N1-PR2 and H5N1-PR7 were associated with confirmed human cases: H5N1-PR2 in the Hong Kong H5N1 outbreak in 1997 and H5N1-PR7 in laboratory confirmed human cases since 2003. H5N1-PR7 also contains a majority of the H5N1 viruses causing avian influenza outbreaks in birds, including the first wave of genotype Z, Qinghai-like and Fujian-like virus lineages. Among the 21 reassortants identified, 13 are first reported here. This study illustrates evolutionary patterns of H5N1 HPAIVs, which may be useful toward pandemic preparedness as well as avian influenza prevention and control.

  11. PA-X is a virulence factor in avian H9N2 influenza virus.

    PubMed

    Gao, Huijie; Xu, Guanlong; Sun, Yipeng; Qi, Lu; Wang, Jinliang; Kong, Weili; Sun, Honglei; Pu, Juan; Chang, Kin-Chow; Liu, Jinhua

    2015-09-01

    H9N2 influenza viruses have been circulating worldwide in multiple avian species, and regularly infect pigs and humans. Recently, a novel protein, PA-X, produced from the PA gene by ribosomal frameshifting, was demonstrated to be an antivirulence factor in pandemic 2009 H1N1, highly pathogenic avian H5N1 and 1918 H1N1 viruses. However, a similar role of PA-X in the prevalent H9N2 avian influenza viruses has not been established. In this study, we compared the virulence and cytopathogenicity of H9N2 WT virus and H9N2 PA-X-deficient virus. Loss of PA-X in H9N2 virus reduced apoptosis and had a marginal effect on progeny virus output in human pulmonary adenocarcinoma (A549) cells. Without PA-X, PA was less able to suppress co-expressed GFP in human embryonic kidney 293T cells. Furthermore, absence of PA-X in H9N2 virus attenuated viral pathogenicity in mice, which showed no mortality, reduced progeny virus production, mild-to-normal lung histopathology, and dampened proinflammatory cytokine and chemokine response. Therefore, unlike previously reported H1N1 and H5N1 viruses, we show that PA-X protein in H9N2 virus is a pro-virulence factor in facilitating viral pathogenicity and that the pro- or antivirulence role of PA-X in influenza viruses is virus strain-dependent.

  12. 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

  13. Detection method for avian influenza viruses in water.

    PubMed

    Rönnqvist, Maria; Ziegler, Thedi; von Bonsdorff, Carl-Henrik; Maunula, Leena

    2012-03-01

    Recent events have shown that humans may become infected with some pathogenic avian influenza A viruses (AIV). Since soil and water, including lakes, rivers, and seashores, may be contaminated by AIV excreted by birds, effective methods are needed for monitoring water for emerging viruses. Combining water filtration with molecular methods such as PCR is a fast and effective way for detecting viruses. The objective of this study was to apply a convenient method for the detection of AIV in natural water samples. Distilled water and lake, river, and seawater were artificially contaminated with AIV (H5N3) and passed through a filter system. AIV was detected from filter membrane by real-time RT-PCR. The performance of Zetapor, SMWP, and Sartobind D5F membranes in recovering influenza viruses was first evaluated using contaminated distilled water. SWMP, which gave the highest virus recoveries, was then compared with a pre-filter combined GF/F filter membrane in a trial using natural water samples. In this study, the cellulose membrane SMWP was found to be practical for recovery of AIVs in water. Viral yields varied between 62.1 and 65.9% in distilled water and between 1 and 16.7% in natural water samples. The borosilicate glass membrane GF/F combined with pre-filter was also feasible in filtering natural water samples with viral yields from 1.98 to 7.33%. The methods described can be used for monitoring fresh and seawater samples for the presence of AIV and to determine the source of AIV transmission in an outbreak situation. PMID:23412765

  14. Detection method for avian influenza viruses in water.

    PubMed

    Rönnqvist, Maria; Ziegler, Thedi; von Bonsdorff, Carl-Henrik; Maunula, Leena

    2012-03-01

    Recent events have shown that humans may become infected with some pathogenic avian influenza A viruses (AIV). Since soil and water, including lakes, rivers, and seashores, may be contaminated by AIV excreted by birds, effective methods are needed for monitoring water for emerging viruses. Combining water filtration with molecular methods such as PCR is a fast and effective way for detecting viruses. The objective of this study was to apply a convenient method for the detection of AIV in natural water samples. Distilled water and lake, river, and seawater were artificially contaminated with AIV (H5N3) and passed through a filter system. AIV was detected from filter membrane by real-time RT-PCR. The performance of Zetapor, SMWP, and Sartobind D5F membranes in recovering influenza viruses was first evaluated using contaminated distilled water. SWMP, which gave the highest virus recoveries, was then compared with a pre-filter combined GF/F filter membrane in a trial using natural water samples. In this study, the cellulose membrane SMWP was found to be practical for recovery of AIVs in water. Viral yields varied between 62.1 and 65.9% in distilled water and between 1 and 16.7% in natural water samples. The borosilicate glass membrane GF/F combined with pre-filter was also feasible in filtering natural water samples with viral yields from 1.98 to 7.33%. The methods described can be used for monitoring fresh and seawater samples for the presence of AIV and to determine the source of AIV transmission in an outbreak situation.

  15. Emergence of fatal avian influenza in New England harbor seals

    USGS Publications Warehouse

    Anthony, S.J.; St. Leger, J. A.; Pugliares, K.; Ip, H.S.; Chan, J.M.; Carpenter, Z.W.; Navarrete-Macias, I.; Sanchez-Leon, M.; Saliki, J.T.; Pedersen, J.; Karesh, W.; Daszak, P.; Rabadan, R.; Rowles, T.; Lipkin, W.I.

    2012-01-01

    From September to December 2011, 162 New England harbor seals died in an outbreak of pneumonia. Sequence analysis of postmortem samples revealed the presence of an avian H3N8 influenza A virus, similar to a virus circulating in North American waterfowl since at least 2002 but with mutations that indicate recent adaption to mammalian hosts. These include a D701N mutation in the viral PB2 protein, previously reported in highly pathogenic H5N1 avian influenza viruses infecting people. Lectin staining and agglutination assays indicated the presence of the avian-preferred SAα-2,3 and mammalian SAα-2,6 receptors in seal respiratory tract, and the ability of the virus to agglutinate erythrocytes bearing either the SAα-2,3 or the SAα-2,6 receptor. The emergence of this A/harbor seal/Massachusetts/1/2011 virus may herald the appearance of an H3N8 influenza clade with potential for persistence and cross-species transmission.

  16. Avian influenza in North America, 2009-2011.

    PubMed

    Pasick, John; Pedersen, Janice; Hernandez, Mario Solis

    2012-12-01

    All reports of avian influenza virus infections in poultry and isolations from wild bird species in Canada, the United States, and Mexico between 2009 and 2011 involved low pathogenic avian influenza. All three countries reported outbreaks of low pathogenic notifiable avian influenza in poultry during this period. The reports involved outbreaks of H5N2 among commercial turkeys in Canada in 2009 and 2010; outbreaks of H5N3 in turkeys in 2009, H5N2 in chickens in 2010, H7N3 in turkeys in 2011, and H7N9 in chickens, turkeys, geese, and guinea fowl in 2011 in the United States; and multiple outbreaks of H5N2 in chickens in Mexico in 2009, 2010, and 2011. Outbreaks of pandemic H1N1 infections in turkey breeder flocks were reported in Canada in 2009 and in the United States in 2010. Active surveillance of live bird markets in the United States led to the detection of H2, H3, H4, H5, H6, and H10 subtypes. Despite the fact that wild bird surveillance programs underwent contraction during this period in both Canada and the United States, H5 and H7 subtypes were still detected.

  17. Correlation between reported human infection with avian influenza A H7N9 virus and cyber user awareness: what can we learn from digital epidemiology?

    PubMed

    Xie, Tiansheng; Yang, Zongxing; Yang, Shigui; Wu, Nanping; Li, Lanjuan

    2014-05-01

    Data on the topic of novel avian influenza A (H7N9) were collected based on the web analysis tool 'Baidu Index', a major Chinese search engine. We found a positive correlation between the volume of H7N9-related 'cyber user awareness' and the epidemic situation during the H7N9 outbreak in China (r=0.98, p<0.01, cumulative; r=0.43, p=0.018, daily) except in the early stage; the ranks of H7N9-related topics changed at different epidemic stages. This study may improve our understanding of the role of web-based media in infectious disease surveillance in China.

  18. International regulations and standards for avian influenza, including the vaccine standards of the World Organisation for Animal Health.

    PubMed

    Bruschke, C J M; Pittman, M; Laddomada, A

    2009-04-01

    For avian influenza the World Organisation for Animal Health (OIE) has laid down international standards on notification, trade, diagnosis, surveillance and the production and use of vaccine. These standards are science- and risk-based to ensure safe trade in poultry and poultry products without unjustified barriers. The European Union, with its 27 Member States, has in place harmonised legislation in line with OIE standards. Early detection, rapid diagnosis, notification and high quality Veterinary Services are crucial for ensuring a rapid response to avian influenza outbreaks and for swiftly reducing the risk of virus spread via trade. Depending on the situation, vaccination may also be a very important tool for disease control. The use of high quality vaccines and postvaccination monitoring are essential for the successful implementation of vaccination. Compliance with international standards is of paramount importance for protecting animal and human health in the global crisis of the highly pathogenic avian influenza of the H5N1 subtype.

  19. ["Emerging infectious diseases". Dengue-fever, West-Nile-fever, SARS, avian influenza, HIV].

    PubMed

    Haas, W; Krause, G; Marcus, U; Stark, K; Ammon, A; Burger, R

    2004-06-01

    Some emerging infectious diseases have recently become endemic in Germany. Others remain confined to specific regions in the world. Physicians notice them only when travelers after infection in endemic areas present themselves with symptoms. Several of these emerging infections will be explained. HIV is an example for an imported pathogen which has become endemic in Germany. SARS and avian influenza are zoonoses with the potential to spread from person to person. Avian influenza in humans provides a possibility for the reassortment of a potential new pandemic strain. Outbreaks of dengue fever in endemic areas are reflected in increased infections in travelers returning from these areas. Currently, West-Nile-virus infections are only imported into Germany. The timely implementation of diagnostic, therapeutic and infection control measures requires physicians to include these diseases in their differential diagnosis. To achieve this goal, good cooperation between physicians, laboratories and the public health service is essential.

  20. China makes an impressive breakthrough in avian influenza virus research - Discovering the "heart" of avian infl uenza virus.

    PubMed

    Li, Y G; Wu, J F; Li, X

    2009-02-01

    The successive appearance of strains of epizootic avian influenza A virus with the subtype H5N1 in China has attracted considerable concern from the public and Chinese authorities. According to the latest WHO estimates as of February 2, 2009, the number of H5N1 virus deaths in China totaled 25, second only to Indonesia and Viet Nam (http://www.who.int/csr/disease/avian_influenza/country/cases_table_2009_02_02/en/index.html). The H5N1 virus is highly contagious among birds and is fatal when transmitted to humans, though the means by which this occurs is still unknown. Owing to the possible variation of the H5N1 prototype virus, together with the fact that it has the propensity to exchange genes with influenza viruses from other species, humans have no natural immunity to the virus. Despite years of efforts, the exact pathogenesis of H5N1 transmission to humans is still not completely clear, nor is potential human-tohuman transmission as could lead to an epidemic or even worldwide pandemic (Enserink M. Science. 2009; 323:324). Unfortunately, current antiviral treatment and therapeutic measures cannot effectively overcome this virulent virus that causes highly pathogenic avian influenza (HPAI). Researchers from around the world are working to study the virology of influenza viruses, including their methods of infiltration, replication, and transcription, to elucidate the mechanisms of unremitting viral infection in terms of aspects such as the virus, host, and environment. These researchers are also working to identify potential molecular targets related to H5N1 for anti-influenza drug intervention. A recent H5N1-related study from China provides encouraging information. According to the People's Daily (Renmin Ribao), a newspaper out of Beijing, professor Liu Yingfang, academician Rao Zihe, and fellow researchers from more than 6 research centers, including the Institute of Biophysics Chinese Academy of Sciences, Nankai University, and Tsinghua University, have

  1. 9 CFR 146.14 - Diagnostic surveillance program for H5/H7 low pathogenic avian influenza.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .../H7 low pathogenic avian influenza. 146.14 Section 146.14 Animals and Animal Products ANIMAL AND PLANT... pathogenic avian influenza. (a) The Official State Agency must develop a diagnostic surveillance program for H5/H7 low pathogenic avian influenza for all poultry in the State. The exact provisions of...

  2. 9 CFR 146.14 - Diagnostic surveillance program for H5/H7 low pathogenic avian influenza.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .../H7 low pathogenic avian influenza. 146.14 Section 146.14 Animals and Animal Products ANIMAL AND PLANT... pathogenic avian influenza. (a) The Official State Agency must develop a diagnostic surveillance program for H5/H7 low pathogenic avian influenza for all poultry in the State. The exact provisions of...

  3. 9 CFR 146.14 - Diagnostic surveillance program for H5/H7 low pathogenic avian influenza.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .../H7 low pathogenic avian influenza. 146.14 Section 146.14 Animals and Animal Products ANIMAL AND PLANT... pathogenic avian influenza. (a) The Official State Agency must develop a diagnostic surveillance program for H5/H7 low pathogenic avian influenza for all poultry in the State. The exact provisions of...

  4. The consequences of climate change at an avian influenza 'hotspot'.

    PubMed

    Brown, V L; Rohani, Pejman

    2012-12-23

    Avian influenza viruses (AIVs) pose significant danger to human health. A key step in managing this threat is understanding the maintenance of AIVs in wild birds, their natural reservoir. Ruddy turnstones (Arenaria interpres) are an atypical bird species in this regard, annually experiencing high AIV prevalence in only one location-Delaware Bay, USA, during their spring migration. While there, they congregate on beaches, attracted by the super-abundance of horseshoe crab eggs. A relationship between ruddy turnstone and horseshoe crab (Limulus polyphemus) population sizes has been established, with a declining horseshoe crab population linked to a corresponding drop in ruddy turnstone population sizes. The effect of this interaction on AIV prevalence in ruddy turnstones has also been addressed. Here, we employ a transmission model to investigate how the interaction between these two species is likely to be altered by climate change. We explore the consequences of this modified interaction on both ruddy turnstone population size and AIV prevalence and show that, if climate change leads to a large enough mismatch in species phenology, AIV prevalence in ruddy turnstones will increase even as their population size decreases. PMID:22933039

  5. Avian influenza in Vietnam: chicken-hearted consumers?

    PubMed

    Figuié, M; Fournier, T

    2008-04-01

    This study, based on quantitative and qualitative surveys conducted from July 2004 to September 2005, examines the perceptions of Hanoi consumers and their reactions to the Avian Influenza epizootic (H5N1). Hanoi consumers clearly link the risk of human contamination by the virus to the preparation and ingestion of poultry. During the first crisis, consumers reacted quickly and intensely (74% of them had already stopped eating poultry in January 2004). Nevertheless, once the crisis abated, they quickly resumed their consumption of poultry. This behavior corresponds to the pattern described by empirical studies of other crises, such as BSE. What is more surprising is the speed with which the different steps of this common pattern succeeded one another. It may be explained by a rapid decrease in risk anxiety. A logit model shows that, soon after the beginning of the crisis, AI risk anxiety was tempered by confidence in the information and recommendations issued by the government concerning AI and, in the long term, by a high perceived self-efficiency to deal with AI. Indeed, not only has poultry consumption been affected in terms of the quantity consumed, but alternative ways of selecting and preparing poultry have also been adopted as anti-risk practices. Risk communication strategies should take this into account, and rely on a previous assessment of consumer practices adopted to deal with the risk. PMID:18419660

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

    PubMed

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

    2010-09-01

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

  7. Serological evidence for avian H9N2 influenza virus infections among Romanian agriculture workers.

    PubMed

    Coman, Alexandru; Maftei, Daniel N; Krueger, Whitney S; Heil, Gary L; Friary, John A; Chereches, Razvan M; Sirlincan, Emanuela; Bria, Paul; Dragnea, Claudiu; Kasler, Iosif; Gray, Gregory C

    2013-12-01

    In recent years, wild birds have introduced multiple highly pathogenic avian influenza (HPAI) H5N1 virus infections in Romanian poultry. In 2005 HPAI infections were widespread among domestic poultry and anecdotal reports suggested domestic pigs may also have been exposed. We sought to examine evidence for zoonotic influenza infections among Romanian agriculture workers. Between 2009 and 2010, 363 adult participants were enrolled in a cross-sectional, seroepidemiological study. Confined animal feeding operation (CAFO) swine workers in Tulcea and small, traditional backyard farmers in Cluj-Napoca were enrolled, as well as a non-animal exposed control group from Cluj-Napoca. Enrollment sera were examined for serological evidence of previous infection with 9 avian and 3 human influenza virus strains. Serologic assays showed no evidence of previous infection with 7 low pathogenic avian influenza viruses or with HPAI H5N1. However, 33 participants (9.1%) had elevated microneutralization antibody titers against avian-like A/Hong Kong/1073/1999(H9N2), 5 with titers ≥ 1:80 whom all reported exposure to poultry. Moderate poultry exposure was significantly associated with elevated titers after controlling for the subjects' age (adjusted OR = 3.6; 95% CI, 1.1-12.1). There was no evidence that previous infection with human H3N2 or H2N2 viruses were confounding the H9N2 seroreactivity. These data suggest that H9N2 virus may have circulated in Romanian poultry and occasionally infected man. PMID:23999337

  8. Phylogenetics and pathogenesis of early avian influenza viruses (H5N2), Nigeria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prior to the first officially recognized outbreaks of highly pathogenic avian influenza (HPAI) in poultry in Nigeria, in February 2006, an effort based at the poultry diagnostic clinic of the University of Ibadan Veterinary Teaching Hospital, was underway to isolate avian influenza viruses from sick...

  9. Antigenic cartographic analysis of H7 avian influenza viruses with chicken serum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antigenic cartography is a relatively new method that can be used to evaluate the antigenic relatedness among avian influenza virus isolates. Evaluation of antigenic relationships among avian influenza viruses can be applied to vaccine design and to understanding the evolution of the virus. Initia...

  10. Protection and virus shedding of falcons vaccinated against highly pathogenic avian influenza A virus (H5N1).

    PubMed

    Lierz, Michael; Hafez, Hafez M; Klopfleisch, Robert; Lüschow, Dörte; Prusas, Christine; Teifke, Jens P; Rudolf, Miriam; Grund, Christian; Kalthoff, Donata; Mettenleiter, Thomas; Beer, Martin; Hardert, Timm

    2007-11-01

    Because fatal infections with highly pathogenic avian influenza A (HPAI) virus subtype H5N1 have been reported in birds of prey, we sought to determine detailed information about the birds' susceptibility and protection after vaccination. Ten falcons vaccinated with an inactivated influenza virus (H5N2) vaccine seroconverted. We then challenged 5 vaccinated and 5 nonvaccinated falcons with HPAI (H5N1). All vaccinated birds survived; all unvaccinated birds died within 5 days. For the nonvaccinated birds, histopathologic examination showed tissue degeneration and necrosis, immunohistochemical techniques showed influenza virus antigen in affected tissues, and these birds shed high levels of infectious virus from the oropharynx and cloaca. Vaccinated birds showed no influenza virus antigen in tissues and shed virus at lower titers from the oropharynx only. Vaccination could protect these valuable birds and, through reduced virus shedding, reduce risk for transmission to other avian species and humans.

  11. Detecting Spread of Avian Influenza A(H7N9) Virus Beyond China.

    PubMed

    Millman, Alexander J; Havers, Fiona; Iuliano, A Danielle; Davis, C Todd; Sar, Borann; Sovann, Ly; Chin, Savuth; Corwin, Andrew L; Vongphrachanh, Phengta; Douangngeun, Bounlom; Lindblade, Kim A; Chittaganpitch, Malinee; Kaewthong, Viriya; Kile, James C; Nguyen, Hien T; Pham, Dong V; Donis, Ruben O; Widdowson, Marc-Alain

    2015-05-01

    During February 2013-March 2015, a total of 602 human cases of low pathogenic avian influenza A(H7N9) were reported; no autochthonous cases were reported outside mainland China. In contrast, since highly pathogenic avian influenza A(H5N1) reemerged during 2003 in China, 784 human cases in 16 countries and poultry outbreaks in 53 countries have been reported. Whether the absence of reported A(H7N9) outside mainland China represents lack of spread or lack of detection remains unclear. We compared epidemiologic and virologic features of A(H5N1) and A(H7N9) and used human and animal influenza surveillance data collected during April 2013-May 2014 from 4 Southeast Asia countries to assess the likelihood that A(H7N9) would have gone undetected during 2014. Surveillance in Vietnam and Cambodia detected human A(H5N1) cases; no A(H7N9) cases were detected in humans or poultry in Southeast Asia. Although we cannot rule out the possible spread of A(H7N9), substantial spread causing severe disease in humans is unlikely.

  12. Detecting Spread of Avian Influenza A(H7N9) Virus Beyond China

    PubMed Central

    Havers, Fiona; Iuliano, A. Danielle; Davis, C. Todd; Sar, Borann; Sovann, Ly; Chin, Savuth; Corwin, Andrew L.; Vongphrachanh, Phengta; Douangngeun, Bounlom; Lindblade, Kim A.; Chittaganpitch, Malinee; Kaewthong, Viriya; Kile, James C.; Nguyen, Hien T.; Pham, Dong V.; Donis, Ruben O.; Widdowson, Marc-Alain

    2015-01-01

    During February 2013–March 2015, a total of 602 human cases of low pathogenic avian influenza A(H7N9) were reported; no autochthonous cases were reported outside mainland China. In contrast, since highly pathogenic avian influenza A(H5N1) reemerged during 2003 in China, 784 human cases in 16 countries and poultry outbreaks in 53 countries have been reported. Whether the absence of reported A(H7N9) outside mainland China represents lack of spread or lack of detection remains unclear. We compared epidemiologic and virologic features of A(H5N1) and A(H7N9) and used human and animal influenza surveillance data collected during April 2013–May 2014 from 4 Southeast Asia countries to assess the likelihood that A(H7N9) would have gone undetected during 2014. Surveillance in Vietnam and Cambodia detected human A(H5N1) cases; no A(H7N9) cases were detected in humans or poultry in Southeast Asia. Although we cannot rule out the possible spread of A(H7N9), substantial spread causing severe disease in humans is unlikely. PMID:25897654

  13. Control of avian influenza: philosophy and perspectives on behalf of migratory birds

    USGS Publications Warehouse

    Friend, Milton

    1992-01-01

    Aquatic birds are considered the primary reservoir for influenza A viruses (Nettles et al., 1987).  However, there is little concern about avian influenza among conservation agencies responsible for the welfare of those species.  IN contrast, the poultry industry has great concern about avian influenza and view aquatic birds as a source for infection of poultry flocks.  In some instances, differences in these perspectives created conflict between conservation agencies and the poultry industry.  I speak on behalf of migratory birds, but philosophy and perspectives offered are intended to be helpful to the poultry industry in their efforts to combat avian influenza.

  14. Replication Capacity of Avian Influenza A(H9N2) Virus in Pet Birds and Mammals, Bangladesh.

    PubMed

    Lenny, Brian J; Shanmuganatham, Karthik; Sonnberg, Stephanie; Feeroz, Mohammed M; Alam, S M Rabiul; Hasan, M Kamrul; Jones-Engel, Lisa; McKenzie, Pamela; Krauss, Scott; Webster, Robert G; Jones, Jeremy C

    2015-12-01

    Avian influenza A(H9N2) is an agricultural and public health threat. We characterized an H9N2 virus from a pet market in Bangladesh and demonstrated replication in samples from pet birds, swine tissues, human airway and ocular cells, and ferrets. Results implicated pet birds in the potential dissemination and zoonotic transmission of this virus.

  15. Avian influenza in ovo vaccination with replication defective recombinant adenovirus in chickens: Vaccine potency, antibody persistence, and maternal antibody transfer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protective immunity against avian influenza (AI) can be elicited in chickens in a single-dose regimen by in ovo vaccination with a replication-competent adenovirus (RCA)-free human adenovirus serotype 5 (Ad)-vector encoding the AI virus (AIV) hemagglutinin (HA). We evaluated vaccine potency, antibo...

  16. Mechanisms of transmission and spread of H5N1 high pathogenicity avian influenza virus in birds and mammals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Eurasian-African H5N1 high pathogenicity avian influenza (HPAI) virus has crossed multiple species barriers to infect poultry, captive and wild birds, carnivorous mammals and humans. The specific transmission mechanisms are unclear in most cases, but experimental studies and field data sug...

  17. Replication Capacity of Avian Influenza A(H9N2) Virus in Pet Birds and Mammals, Bangladesh

    PubMed Central

    Lenny, Brian J.; Shanmuganatham, Karthik; Sonnberg, Stephanie; Feeroz, Mohammed M.; Alam, S.M. Rabiul; Hasan, M. Kamrul; Jones-Engel, Lisa; McKenzie, Pamela; Krauss, Scott; Webster, Robert G.

    2015-01-01

    Avian influenza A(H9N2) is an agricultural and public health threat. We characterized an H9N2 virus from a pet market in Bangladesh and demonstrated replication in samples from pet birds, swine tissues, human airway and ocular cells, and ferrets. Results implicated pet birds in the potential dissemination and zoonotic transmission of this virus. PMID:26583371

  18. Replication Capacity of Avian Influenza A(H9N2) Virus in Pet Birds and Mammals, Bangladesh.

    PubMed

    Lenny, Brian J; Shanmuganatham, Karthik; Sonnberg, Stephanie; Feeroz, Mohammed M; Alam, S M Rabiul; Hasan, M Kamrul; Jones-Engel, Lisa; McKenzie, Pamela; Krauss, Scott; Webster, Robert G; Jones, Jeremy C

    2015-12-01

    Avian influenza A(H9N2) is an agricultural and public health threat. We characterized an H9N2 virus from a pet market in Bangladesh and demonstrated replication in samples from pet birds, swine tissues, human airway and ocular cells, and ferrets. Results implicated pet birds in the potential dissemination and zoonotic transmission of this virus. PMID:26583371

  19. 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.

  20. 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. PMID:25952001

  1. The role of the legal and illegal trade of live birds and avian products in the spread of avian influenza.

    PubMed

    van den Berg, T

    2009-04-01

    The panzootic of the H5N1 strain of highly pathogenic avian influenza has become an international crisis. All parts of the world are now considered at risk due to trade globalisation, with the worldwide movement of animals, products and humans, and because of the possible spread of the virus through the migration of wild birds. The risk of introducing notifiable avian influenza (NAI) through trade depends on several factors, including the disease status of the exporting country and the type of products. The highest risk occurs in the trade of live birds. It is important to assess and manage these risks to ensure that global trade does not result in the dissemination of NAI. However, it is also important that the risk of infection is not used as an unjustified trade barrier. The role of the regulatory authorities is thus to facilitate the safe trade of animal products according to international guidelines. Nevertheless, the balance between acceptable risk and safe trade is difficult to achieve. Since the movements of poultry and birds are sometimes difficult to trace, the signature or 'identity card' of each isolated virus can be very informative. Indeed, sequencing the genes of H5N1 and other avian influenza viruses has assisted greatly in establishing links and highlighting differences between isolates from different countries and tracing the possible source of introduction. Recent examples from Asia, Europe and Africa, supported by H5N1 molecular fingerprinting, have demonstrated that the sources of introduction can be many and no route should be underestimated.

  2. The role of the legal and illegal trade of live birds and avian products in the spread of avian influenza.

    PubMed

    van den Berg, T

    2009-04-01

    The panzootic of the H5N1 strain of highly pathogenic avian influenza has become an international crisis. All parts of the world are now considered at risk due to trade globalisation, with the worldwide movement of animals, products and humans, and because of the possible spread of the virus through the migration of wild birds. The risk of introducing notifiable avian influenza (NAI) through trade depends on several factors, including the disease status of the exporting country and the type of products. The highest risk occurs in the trade of live birds. It is important to assess and manage these risks to ensure that global trade does not result in the dissemination of NAI. However, it is also important that the risk of infection is not used as an unjustified trade barrier. The role of the regulatory authorities is thus to facilitate the safe trade of animal products according to international guidelines. Nevertheless, the balance between acceptable risk and safe trade is difficult to achieve. Since the movements of poultry and birds are sometimes difficult to trace, the signature or 'identity card' of each isolated virus can be very informative. Indeed, sequencing the genes of H5N1 and other avian influenza viruses has assisted greatly in establishing links and highlighting differences between isolates from different countries and tracing the possible source of introduction. Recent examples from Asia, Europe and Africa, supported by H5N1 molecular fingerprinting, have demonstrated that the sources of introduction can be many and no route should be underestimated. PMID:19618621

  3. Global avian influenza surveillance in wild birds: a strategy to capture viral diversity.

    PubMed

    Machalaba, Catherine C; Elwood, Sarah E; Forcella, Simona; Smith, Kristine M; Hamilton, Keith; Jebara, Karim B; Swayne, David E; Webby, Richard J; Mumford, Elizabeth; Mazet, Jonna A K; Gaidet, Nicolas; Daszak, Peter; Karesh, William B

    2015-04-01

    Wild birds play a major role in the evolution, maintenance, and spread of avian influenza viruses. However, surveillance for these viruses in wild birds is sporadic, geographically biased, and often limited to the last outbreak virus. To identify opportunities to optimize wild bird surveillance for understanding viral diversity, we reviewed responses to a World Organisation for Animal Health-administered survey, government reports to this organization, articles on Web of Knowledge, and the Influenza Research Database. At least 119 countries conducted avian influenza virus surveillance in wild birds during 2008-2013, but coordination and standardization was lacking among surveillance efforts, and most focused on limited subsets of influenza viruses. Given high financial and public health burdens of recent avian influenza outbreaks, we call for sustained, cost-effective investments in locations with high avian influenza diversity in wild birds and efforts to promote standardized sampling, testing, and reporting methods, including full-genome sequencing and sharing of isolates with the scientific community.

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

    PubMed Central

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

    2014-01-01

    Background Highly pathogenic avian influenza A (HPAI) H5N1 viruses have infected poultry and wild birds on three continents with more than 600 reported human cases (59% mortality) since 2003. Wild aquatic birds are the natural reservoir for avian influenza A viruses, and migratory birds have been documented with HPAI H5N1 virus infection. Since 2005, clade 2.2 HPAI H5N1 viruses have spread from Asia to many countries. Objectives We conducted a cross-sectional seroepidemiological survey in Anchorage and western Alaska to identify possible behaviors associated with migratory bird exposure and measure seropositivity to HPAI H5N1. Methods We enrolled rural subsistence bird hunters and their families, urban sport hunters, wildlife biologists, and a comparison group without bird contact. We interviewed participants regarding their exposures to wild birds and collected blood to perform serologic testing for antibodies against a clade 2.2 HPAI H5N1 virus strain. Results Hunters and wildlife biologists reported exposures to wild migratory birds that may confer risk of infection with avian influenza A viruses, although none of the 916 participants had evidence of seropositivity to HPAI H5N1. Conclusions We characterized wild bird contact among Alaskans and behaviors that may influence risk of infection with avian influenza A viruses. Such knowledge can inform surveillance and risk communication surrounding HPAI H5N1 and other influenza viruses in a population with exposure to wild birds at a crossroads of intercontinental migratory flyways. PMID:24828535

  5. Nurses' fears and professional obligations concerning possible human-to-human avian flu.

    PubMed

    Tzeng, Huey-Ming; Yin, Chang-Yi

    2006-09-01

    This survey aimed to illustrate factors that contribute to nurses' fear when faced with a possible human-to-human avian flu pandemic and their willingness to care for patients with avian flu in Taiwan. The participants were nursing students with a lesser nursing credential who were currently enrolled in a bachelor degree program in a private university in southern Taiwan. Nearly 42% of the nurses did not think that, if there were an outbreak of avian flu, their working hospitals would have sufficient infection control measures and equipment to prevent nosocomial infection in their working environment. About 57% of the nurse participants indicated that they were willing to care for patients infected with avian influenza. Nurses' fear about an unknown infectious disease, such as the H5N1 influenza virus, could easily be heightened to levels above those occurring during the 2003 severe acute respiratory syndrome outbreak in Taiwan.

  6. Detection of antibodies against avian influenza virus by protein microarray using nucleoprotein expressed in insect cells.

    PubMed

    Zhao, Yuhui; Wang, Xiurong; Chen, Pucheng; Zeng, Xianying; Bao, Hongmei; Wang, Yunhe; Xu, Xiaolong; Jiang, Yongping; Chen, Hualan; Li, Guangxing

    2015-04-01

    Avian influenza (AI) is an infectious disease caused by avian influenza viruses (AIVs) which belong to the influenza virus A group. AI causes tremendous economic losses in poultry industry and pose great threatens to human health. Active serologic surveillance is necessary to prevent and control the spread of AI. In this study, a protein microarray using nucleoprotein (NP) of H5N1 AIV expressed in insect cells was developed to detect antibodies against AIV NP protein. The protein microarray was used to test Newcastle disease virus (NDV), infectious bursal disease virus (IBDV), AIV positive and negative sera. The results indicated that the protein microarray could hybridize specifically with antibodies against AIV with strong signals and without cross-hybridization. Moreover, 76 field serum samples were detected by microarray, enzyme-linked immunosorbent assay (ELISA) and hemagglutination inhibition test (HI). The positive rate was 92.1% (70/76), 93.4% (71/76) and 89.4% (68/76) by protein microarray, ELISA and HI test, respectively. Compared with ELISA, the microarray showed 100% (20/20) agreement ratio in chicken and 98.2% (55/56) in ornamental bird. In conclusion, this method provides an alternative serological diagnosis for influenza antibody screening and will provide a basis for the development of protein microarrays that can be used to respectively detect antibodies of different AIV subtypes and other pathogens. PMID:25650059

  7. 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. PMID:27066713

  8. 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.

  9. Genetic Analysis of Avian Influenza Viruses: Cocirculation of Avian Influenza Viruses with Allele A and B Nonstructural Gene in Northern Pintail (Anas acuta) Ducks Wintering in Japan

    PubMed Central

    Jahangir, Alam; Ruenphet, Sakchai; Sultana, Nadia; Shoham, Dany; Takehara, Kazuaki

    2012-01-01

    The pandemic influenza virus strains of 1918 (H1N1), 1957 (H2N2), 1968 (H3N2), and 2009 (H1N1) have genes related to avian influenza viruses (AIVs). The nonstructural (NS) gene of AIVs plays a significant role in host-viral interaction. However, little is known about the degree of diversity of this gene in Northern pintail (Anas acuta) ducks wintering in Japan. This study describes characteristics of pintail-originated H1N1, H1N2, H1N3, H5N2, H5N3, H5N9, and H7N7 viruses. Most of the viruses were revealed to be avian strains and not related to pandemic and seasonal flu strains. Nevertheless, the NP genes of 62.5% (5/8) viruses were found closely related to a A/swine/Korea/C12/08, indicating exchange of genetic material and ongoing mammalian-linked evolution of AIVs. Besides, all the viruses, except Aomori/422/07 H1N1, contain PSIQSR∗GLF motif usually found in avian, porcine, and human H1 strains. The Aomori/422/07 H1N1 has a PSVQSR∗GLF motif identical to a North American strain. This findings linked to an important intercontinental, Asian-American biogeographical interface. Phylogenetically all the viruses were clustered in Eurasian lineage. Cocirculation of allele A and B (NS gene) viruses was evident in the study implying the existence of a wide reservoir of influenza A viruses in pintail wintering in Japan. PMID:23320157

  10. Unique Determinants of Neuraminidase Inhibitor Resistance among N3, N7, and N9 Avian Influenza Viruses

    PubMed Central

    Song, Min-Suk; Marathe, Bindumadhav M.; Kumar, Gyanendra; Wong, Sook-San; Rubrum, Adam; Zanin, Mark; Choi, Young-Ki; Webster, Robert G.; Govorkova, Elena A.

    2015-01-01

    ABSTRACT Human infections with avian influenza viruses are a serious public health concern. The neuraminidase (NA) inhibitors (NAIs) are the frontline anti-influenza drugs and are the major option for treatment of newly emerging influenza. Therefore, it is essential to identify the molecular markers of NAI resistance among specific NA subtypes of avian influenza viruses to help guide clinical management. NAI-resistant substitutions in NA subtypes other than N1 and N2 have been poorly studied. Here, we identified NA amino acid substitutions associated with NAI resistance among influenza viruses of N3, N7, and N9 subtypes which have been associated with zoonotic transmission. We applied random mutagenesis and generated recombinant influenza viruses carrying single or double NA substitution(s) with seven internal genes from A/Puerto Rico/8/1934 (H1N1) virus. In a fluorescence-based NA inhibition assay, we identified three categories of NA substitutions associated with reduced inhibition by NAIs (oseltamivir, zanamivir, and peramivir): (i) novel subtype-specific substitutions in or near the enzyme catalytic site (R152W, A246T, and D293N, N2 numbering), (ii) subtype-independent substitutions (E119G/V and/or D and R292K), and (iii) substitutions previously reported in other subtypes (Q136K, I222M, and E276D). Our data show that although some markers of resistance are present across NA subtypes, other subtype-specific markers can only be determined empirically. IMPORTANCE The number of humans infected with avian influenza viruses is increasing, raising concerns of the emergence of avian influenza viruses resistant to neuraminidase (NA) inhibitors (NAIs). Since most studies have focused on NAI-resistance in human influenza viruses, we investigated the molecular changes in NA that could confer NAI resistance in avian viruses grown in immortalized monolayer cells, especially those of the N3, N7, and N9 subtypes, which have caused human infections. We identified not only

  11. Genetic characterization of H1 avian influenza viruses isolated from migratory birds and domestic ducks in Korea.

    PubMed

    Jeong, Ok-Mi; Kim, Yong-Joo; Choi, Jun-Gu; Kang, Hyun-Mi; Kim, Min-Chul; Kwon, Jun-Hun; Lee, Youn-Jeong

    2011-02-01

    H1 avian influenza viruses (AIVs) isolated from migratory birds and domestic ducks from 2003 to 2007 were analyzed to determine their genetic relationship. Phylogenic analysis with nucleotide sequences of all eight gene segments showed that 13 H1 AIVs from migratory birds and domestic ducks belonged to Eurasian avian lineages and were closely related to each other. Compared with H1 influenza viruses of swine or human origin in Korea, there was no evidence of reassortment among the human, swine, and avian hosts. Our results show that H1 AIVs isolated in Korea from 2003 to 2007 were genetically stable. However, continued surveillance is needed considering the role of migratory birds and domestic duck as a source of AIVs.

  12. Effects of the Q223R mutation in the hemagglutinin (HA) of egg-adapted pandemic 2009 (H1N1) influenza A virus on virus growth and binding of HA to human- and avian-type cell receptors.

    PubMed

    Suptawiwat, O; Jeamtua, W; Boonarkart, Ch; Kongchanagul, A; Puthawathana, P; Auewarakul, P

    2013-01-01

    The 2009 swine-origin influenza A virus (H1N1) and its initial reassortant vaccine strains did not grow well in embryonated eggs. The glutamine to arginine mutation at the amino acid position 223 (Q223R) of the hemagglutinin (HA) gene is the major mutation previously found in egg-adapted 2009 H1N1 strains and shown to enhance viral growth in embryonated eggs. However, the effect of this mutation on the receptor-binding preference had not been directly demonstrated. In this study, the Q223R mutation was shown to change the viral HA binding preference from the human-type receptor, α2,6-linked sialic acid, to the avian-type receptor, α2,3-linked sialic acid; and to enhance the viral growth in embryonated eggs but not in cell culture.

  13. Novel reassortant highly pathogenic avian influenza (H5N5) viruses in domestic ducks, China.

    PubMed

    Gu, Min; Liu, Wenbo; Cao, Yongzhong; Peng, Daxin; Wang, Xiaobo; Wan, Hongquan; Zhao, Guo; Xu, Quangang; Zhang, Wei; Song, Qingqing; Li, Yanfang; Liu, Xiufan

    2011-06-01

    In China, domestic ducks and wild birds often share the same water, in which influenza viruses replicate preferentially. Isolation of 2 novel reassortant highly pathogenic avian influenza (H5N5) viruses from apparently healthy domestic ducks highlights the role of these ducks as reassortment vessels. Such new subtypes of influenza viruses may pose a pandemic threat.

  14. SnapShot: Evolution of human influenza A viruses.

    PubMed

    Wendel, Isabel; Matrosovich, Mikhail; Klenk, Hans Dieter

    2015-03-11

    The major natural hosts of influenza A viruses are wild aquatic birds. Occasionally, viruses are transmitted to mammalian and other avian species, including humans. Due to the high mutation rate and reassortment of the viral genome, the viruses may undergo adaptation to humans and then give rise to a pandemic.

  15. [An overview of surveillance of avian influenza viruses in wild birds].

    PubMed

    Zhu, Yun; Shi, Jing-Hong; Shu, Yue-Long

    2014-05-01

    Wild birds (mainly Anseriformes and Charadriiformes) are recognized as the natural reservoir of avian influenza viruses (AIVs). The long-term surveillance of AIVs in wild birds has been conducted in North America and Europe since 1970s. More and more surveillance data revealed that all the HA and NA subtypes of AIVs were identified in the wild ducks, shorebirds, and gulls, and the AIVs circulating in wild birds were implicated in the outbreaks of AIVs in poultry and humans. Therefore, the AIVs in wild birds pose huge threat to poultry industry and human health. To gain a better understanding of the ecology and epidemiology of AIVs in wild birds, we summarize the transmission of AIVs between wild birds, poultry, and humans, the main results of surveillance of AIVs in wild birds worldwide and methods for surveillance, and the types of samples and detection methods for AIVs in wild birds, which would be vital for the effective control of avian influenza and response to possible influenza pandemic.

  16. Mapping the risk of avian influenza in wild birds in the US

    PubMed Central

    2010-01-01

    Background Avian influenza virus (AIV) is an important public health issue because pandemic influenza viruses in people have contained genes from viruses that infect birds. The H5 and H7 AIV subtypes have periodically mutated from low pathogenicity to high pathogenicity form. Analysis of the geographic distribution of AIV can identify areas where reassortment events might occur and how high pathogenicity influenza might travel if it enters wild bird populations in the US. Modelling the number of AIV cases is important because the rate of co-infection with multiple AIV subtypes increases with the number of cases and co-infection is the source of reassortment events that give rise to new strains of influenza, which occurred before the 1968 pandemic. Aquatic birds in the orders Anseriformes and Charadriiformes have been recognized as reservoirs of AIV since the 1970s. However, little is known about influenza prevalence in terrestrial birds in the order Passeriformes. Since passerines share the same habitat as poultry, they may be more effective transmitters of the disease to humans than aquatic birds. We analyze 152 passerine species including the American Robin (Turdus migratorius) and Swainson's Thrush (Catharus ustulatus). Methods We formulate a regression model to predict AIV cases throughout the US at the county scale as a function of 12 environmental variables, sampling effort, and proximity to other counties with influenza outbreaks. Our analysis did not distinguish between types of influenza, including low or highly pathogenic forms. Results Analysis of 13,046 cloacal samples collected from 225 bird species in 41 US states between 2005 and 2008 indicates that the average prevalence of influenza in passerines is greater than the prevalence in eight other avian orders. Our regression model identifies the Great Plains and the Pacific Northwest as high-risk areas for AIV. Highly significant predictors of AIV include the amount of harvested cropland and the first

  17. Large-Scale Avian Influenza Surveillance in Wild Birds throughout the United States

    PubMed Central

    Bevins, Sarah N.; Pedersen, Kerri; Lutman, Mark W.; Baroch, John A.; Schmit, Brandon S.; Kohler, Dennis; Gidlewski, Thomas; Nolte, Dale L.; Swafford, Seth R.; DeLiberto, Thomas J.

    2014-01-01

    Avian influenza is a viral disease that primarily infects wild and domestic birds, but it also can be transmitted to a variety of mammals. In 2006, the United States of America Departments of Agriculture and Interior designed a large-scale, interagency surveillance effort that sought to determine if highly pathogenic avian influenza viruses were present in wild bird populations within the United States of America. This program, combined with the Canadian and Mexican surveillance programs, represented the largest, coordinated wildlife disease surveillance program ever implemented. Here we analyze data from 197,885 samples that were collected from over 200 wild bird species. While the initial motivation for surveillance focused on highly pathogenic avian influenza, the scale of the data provided unprecedented information on the ecology of avian influenza viruses in the United States, avian influenza virus host associations, and avian influenza prevalence in wild birds over time. Ultimately, significant advances in our knowledge of avian influenza will depend on both large-scale surveillance efforts and on focused research studies. PMID:25116079

  18. Large-scale avian influenza surveillance in wild birds throughout the United States.

    PubMed

    Bevins, Sarah N; Pedersen, Kerri; Lutman, Mark W; Baroch, John A; Schmit, Brandon S; Kohler, Dennis; Gidlewski, Thomas; Nolte, Dale L; Swafford, Seth R; DeLiberto, Thomas J

    2014-01-01

    Avian influenza is a viral disease that primarily infects wild and domestic birds, but it also can be transmitted to a variety of mammals. In 2006, the United States of America Departments of Agriculture and Interior designed a large-scale, interagency surveillance effort that sought to determine if highly pathogenic avian influenza viruses were present in wild bird populations within the United States of America. This program, combined with the Canadian and Mexican surveillance programs, represented the largest, coordinated wildlife disease surveillance program ever implemented. Here we analyze data from 197,885 samples that were collected from over 200 wild bird species. While the initial motivation for surveillance focused on highly pathogenic avian influenza, the scale of the data provided unprecedented information on the ecology of avian influenza viruses in the United States, avian influenza virus host associations, and avian influenza prevalence in wild birds over time. Ultimately, significant advances in our knowledge of avian influenza will depend on both large-scale surveillance efforts and on focused research studies.

  19. 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.

  20. Local poultry biosecurity risks to highly pathogenic avian influenza in Kaduna State, Nigeria.

    PubMed

    Paul, Abdu A; Assam, Assam; Ndang, Tabe-Ntui L

    2013-01-01

    The study appraised local poultry biosecurity risks to highly pathogenic avian influenza by assessing farmers' knowledge, beliefs and poultry practices using a standard questionnaire. Farmers' knowledge on transmission and prevention was high but low on disease recognition. Radio was ineffective at informing Islamic educated farmers. Extensive knowledge on transmission and protection did not result in behavioural change as farmers engaged in risky practices of selling, eating or medicating infected poultry and not reporting poultry death. Islamic educated farmers do not believe highly pathogenic avian influenza is a serious and preventable disease. Women are more likely to self medicate when experiencing influenza-like illness. Audio-visual aids would improve avian influenza recognition while involvement of community leaders would enhance disease reporting. Outbreak of highly pathogenic avian influenza in local poultry in Nigeria would follow a similar pattern in Southeast Asia if the risk perception among farmers is not urgently articulated.

  1. Serological survey of avian influenza virus infection in non-avian wildlife in Xinjiang, China.

    PubMed

    Wei, Yu-Rong; Yang, Xue-Yun; Li, Yuan-Guo; Wei, Jie; Ma, Wen-Ge; Ren, Zhi-Guang; Guo, Hui-Ling; Wang, Tie-Cheng; Mi, Xiao-Yun; Adili, Gulizhati; Miao, Shu-Kui; Shaha, Ayiqiaolifan; Gao, Yu-Wei; Huang, Jiong; Xia, Xian-Zhu

    2016-04-01

    We conducted a serological survey to detect antibodies against avian influenza virus (AIV) in Gazella subgutturosa, Canis lupus, Capreolus pygargus, Sus scrofa, Cervus elaphus, Capra ibex, Ovis ammon, Bos grunniens and Pseudois nayaur in Xinjiang, China. Two hundred forty-six sera collected from 2009 to 2013 were assayed for antibodies against H5, H7 and H9 AIVs using hemagglutination inhibition (HI) tests and a pan-influenza competitive ELISA. Across all tested wildlife species, 4.47 % harbored anti-AIV antibodies that were detected by the HI assay. The seroprevalence for each AIV subtype across all species evaluated was 0 % for H5 AIV, 0.81 % for H7 AIV, and 3.66 % for H9 AIV. H7-reactive antibodies were found in Canis lupus (9.09 %) and Ovis ammon (4.55 %). H9-reactive antibodies were found in Gazella subgutturosa (4.55 %), Canis lupus (27.27 %), Pseudois nayaur (23.08 %), and Ovis ammon (4.55 %). The pan-influenza competitive ELISA results closely corresponded to the cumulative prevalence of AIV exposure as measured by subtype-specific HI assays, suggesting that H7 and H9 AIV subtypes predominate in the wildlife species evaluated. These data provide evidence of prior infection with H7 and H9 AIVs in non-avian wildlife in Xinjiang, China.

  2. Serological survey of avian influenza virus infection in non-avian wildlife in Xinjiang, China.

    PubMed

    Wei, Yu-Rong; Yang, Xue-Yun; Li, Yuan-Guo; Wei, Jie; Ma, Wen-Ge; Ren, Zhi-Guang; Guo, Hui-Ling; Wang, Tie-Cheng; Mi, Xiao-Yun; Adili, Gulizhati; Miao, Shu-Kui; Shaha, Ayiqiaolifan; Gao, Yu-Wei; Huang, Jiong; Xia, Xian-Zhu

    2016-04-01

    We conducted a serological survey to detect antibodies against avian influenza virus (AIV) in Gazella subgutturosa, Canis lupus, Capreolus pygargus, Sus scrofa, Cervus elaphus, Capra ibex, Ovis ammon, Bos grunniens and Pseudois nayaur in Xinjiang, China. Two hundred forty-six sera collected from 2009 to 2013 were assayed for antibodies against H5, H7 and H9 AIVs using hemagglutination inhibition (HI) tests and a pan-influenza competitive ELISA. Across all tested wildlife species, 4.47 % harbored anti-AIV antibodies that were detected by the HI assay. The seroprevalence for each AIV subtype across all species evaluated was 0 % for H5 AIV, 0.81 % for H7 AIV, and 3.66 % for H9 AIV. H7-reactive antibodies were found in Canis lupus (9.09 %) and Ovis ammon (4.55 %). H9-reactive antibodies were found in Gazella subgutturosa (4.55 %), Canis lupus (27.27 %), Pseudois nayaur (23.08 %), and Ovis ammon (4.55 %). The pan-influenza competitive ELISA results closely corresponded to the cumulative prevalence of AIV exposure as measured by subtype-specific HI assays, suggesting that H7 and H9 AIV subtypes predominate in the wildlife species evaluated. These data provide evidence of prior infection with H7 and H9 AIVs in non-avian wildlife in Xinjiang, China. PMID:26733295

  3. The spread of avian influenza H5N1 virus; a pandemic threat to mankind.

    PubMed

    Chutinimitkul, Salin; Payungporn, Sunchai; Chieochansin, Thaweesak; Suwannakarn, Kamol; Theamboonlers, Apiradee; Poovorawan, Yong

    2006-09-01

    Influenza A H5N1 virus infection presents a major public health problem in Asian and Eurasian countries. The World Health organization has voiced their concerns about a potential pandemic with the imminent threat to humankind. In 1997, an outbreak of highly pathogenic H5N1 virus emerged and caused severe systemic disease among poultry and humans in Hong Kong. This article reviews the magnitude of the 2004-2006 outbreaks in various countries and highlights the highly pathogenic avian influenza (HPAI) subtype H5N1 virus as the cause of a major epidemic with potentially vast repercussions on economics, public health and society at large. Not only has this avian influenza (AI) virus infected poultry but has also proven highly pathogenic and fatal to mammalian species including humans and felines. The present review draws a comprehensive picture encompassing epidemiology, inter-species transmission and genetic characterization of this highly virulent virus. Moreover, laboratory diagnostic techniques, vaccination strategies and antiviral therapies aimed at outbreak control and management are also discussed.

  4. Cloning and Expression of Highly Pathogenic Avian Influenza Virus Full-Length Nonstructural Gene in Pichia pastoris

    PubMed Central

    Abubakar, M. B.; Aini, I.; Omar, A. R.; Hair-Bejo, M.

    2011-01-01

    Avian influenza (AI) is a highly contagious and rapidly evolving pathogen of major concern to the poultry industry and human health. Rapid and accurate detection of avian influenza virus is a necessary tool for control of outbreaks and surveillance. The AI virus A/Chicken/Malaysia/5858/2004 (H5N1) was used as a template to produce DNA clones of the full-length NS1 genes via reverse transcriptase synthesis of cDNA by PCR amplification of the NS1 region. Products were cloned into pCR2.0 TOPO TA plasmid and subsequently subcloned into pPICZαA vector to construct a recombinant plasmid. Recombinant plasmid designated as pPICZαA-NS1 gene was confirmed by PCR colony screening, restriction enzyme digestion, and nucleotide sequence analysis. The recombinant plasmid was transformed into Pichia pastoris GS115 strain by electroporation, and expressed protein was identified by SDS-PAGE and western blotting. A recombinant protein of approximately ~28 kDa was produced. The expressed protein was able to bind a rabbit polyclonal antibody of nonstructural protein (NS1) avian influenza virus H5N1. The result of the western blotting and solid-phase ELISA assay using H5N1 antibody indicated that the recombinant protein produced retained its antigenicity. This further indicates that Pichia pastoris could be an efficient expression system for a avian influenza virus nonstructural (NS1). PMID:21541235

  5. Economic epidemiology of avian influenza on smallholder poultry farms☆

    PubMed Central

    Boni, Maciej F.; Galvani, Alison P.; Wickelgren, Abraham L.; Malani, Anup

    2013-01-01

    Highly pathogenic avian influenza (HPAI) is often controlled through culling of poultry. Compensating farmers for culled chickens or ducks facilitates effective culling and control of HPAI. However, ensuing price shifts can create incentives that alter the disease dynamics of HPAI. Farmers control certain aspects of the dynamics by setting a farm size, implementing infection control measures, and determining the age at which poultry are sent to market. Their decisions can be influenced by the market price of poultry which can, in turn, be set by policy makers during an HPAI outbreak. Here, we integrate these economic considerations into an epidemiological model in which epidemiological parameters are determined by an outside agent (the farmer) to maximize profit from poultry sales. Our model exhibits a diversity of behaviors which are sensitive to (i) the ability to identify infected poultry, (ii) the average price of infected poultry, (iii) the basic reproductive number of avian influenza, (iv) the effect of culling on the market price of poultry, (v) the effect of market price on farm size, and (vi) the effect of poultry density on disease transmission. We find that under certain market and epidemiological conditions, culling can increase farm size and the total number of HPAI infections. Our model helps to inform the optimization of public health outcomes that best weigh the balance between public health risk and beneficial economic outcomes for farmers. PMID:24161559

  6. Economic epidemiology of avian influenza on smallholder poultry farms.

    PubMed

    Boni, Maciej F; Galvani, Alison P; Wickelgren, Abraham L; Malani, Anup

    2013-12-01

    Highly pathogenic avian influenza (HPAI) is often controlled through culling of poultry. Compensating farmers for culled chickens or ducks facilitates effective culling and control of HPAI. However, ensuing price shifts can create incentives that alter the disease dynamics of HPAI. Farmers control certain aspects of the dynamics by setting a farm size, implementing infection control measures, and determining the age at which poultry are sent to market. Their decisions can be influenced by the market price of poultry which can, in turn, be set by policy makers during an HPAI outbreak. Here, we integrate these economic considerations into an epidemiological model in which epidemiological parameters are determined by an outside agent (the farmer) to maximize profit from poultry sales. Our model exhibits a diversity of behaviors which are sensitive to (i) the ability to identify infected poultry, (ii) the average price of infected poultry, (iii) the basic reproductive number of avian influenza, (iv) the effect of culling on the market price of poultry, (v) the effect of market price on farm size, and (vi) the effect of poultry density on disease transmission. We find that under certain market and epidemiological conditions, culling can increase farm size and the total number of HPAI infections. Our model helps to inform the optimization of public health outcomes that best weigh the balance between public health risk and beneficial economic outcomes for farmers.

  7. Practical aspects of vaccination of poultry against avian influenza virus.

    PubMed

    Spackman, Erica; Pantin-Jackwood, Mary J

    2014-12-01

    Although little has changed in vaccine technology for avian influenza virus (AIV) in the past 20 years, the approach to vaccination of poultry (chickens, turkeys and ducks) for avian influenza has evolved as highly pathogenic AIV has become endemic in several regions of the world. Vaccination for low pathogenicity AIV is also becoming routine in regions where there is a high level of field challenge. In contrast, some countries will not use vaccination at all and some will only use it on an emergency basis during eradication efforts (i.e. stamping-out). There are pros and cons to each approach and, since every outbreak situation is different, no one method will work equally well in all situations. Numerous practical aspects must be considered when developing an AIV control program with vaccination as a component, such as: (1) the goals of vaccination must be defined; (2) the population to be vaccinated must be clearly identified; (3) there must be a plan to obtain and administer good quality vaccine in a timely manner and to achieve adequate coverage with the available resources; (4) risk factors for vaccine failure should be mitigated as much as possible; and, most importantly, (5) biosecurity must be maintained as much as possible, if not enhanced, during the vaccination period.

  8. Immunochromatographic strip assay development for avian influenza antibody detection.

    PubMed

    Cheng, Yu-Ling; Wang, Lih-Chiann; Wang, Ching-Ho

    2015-11-01

    To detect antibody on pen-side is a rapid way to know the avian influenza (AI) infectious status in a chicken flock. The purpose of this study was to develop an immunochromatographic strip (ICS) assay to detect the antibody against the AI virus (AIV) for field applications. The ICS was constructed by fixing an AIV strain A/chicken/Taiwan/2838V/2000 (H6N1) onto a nitrocellulose membrane as the antigen at the test line and goat anti-rabbit IgG antibody at the control line. The colloidal gold conjugated with rabbit anti-chicken IgG was used as the tracer. The present ICS was used to detect antibodies against avian influenza virus in 326 chicken serum samples from the field. Compared with HI, this ICS could detect antibodies against H5 and H6 AIVs. The hemagglutination inhibition (HI) test was used as the standard to evaluate the ICS accuracy. The results showed that the sensitivity and specificity of this ICS reached 95.2% (159/167) and 94.3% (150/159), respectively. The Kappa value of the HI and ICS was 0.896 (P < 0.001). In conclusion, this ICS could be used as a rapid test to detect antibodies against AIVs in the field. PMID:26753244

  9. Inactivation of various influenza strains to model avian influenza (Bird Flu) with various disinfectant chemistries.

    SciTech Connect

    Oberst, R. D.; Bieker, Jill Marie; Souza, Caroline Ann

    2005-12-01

    Due to the grave public health implications and economic impact possible with the emergence of the highly pathogenic avian influenza A isolate, H5N1, currently circulating in Asia we have evaluated the efficacy of various disinfectant chemistries against surrogate influenza A strains. Chemistries included in the tests were household bleach, ethanol, Virkon S{reg_sign}, and a modified version of the Sandia National Laboratories developed DF-200 (DF-200d, a diluted version of the standard DF-200 formulation). Validation efforts followed EPA guidelines for evaluating chemical disinfectants against viruses. The efficacy of the various chemistries was determined by infectivity, quantitative RNA, and qualitative protein assays. Additionally, organic challenges using combined poultry feces and litter material were included in the experiments to simulate environments in which decontamination and remediation will likely occur. In all assays, 10% bleach and Sandia DF-200d were the most efficacious treatments against two influenza A isolates (mammalian and avian) as they provided the most rapid and complete inactivation of influenza A viruses.

  10. Zoonotic infections with avian influenza A viruses and vaccine preparedness: a game of "mix and match"

    PubMed Central

    2014-01-01

    Various direct avian-to-human transmissions of influenza A virus subtypes upon exposure to infected poultry have been previously observed in the past decades. Although some of these strains caused lethal infections, the lack of sustained person-to-person transmission has been the major factor that prevented these viruses from causing new pandemics. In 2013, three (A/H7N9, A/H6N1, and A/H10N8) novel avian influenza viruses (AIVs) yet again breached the animal-human host species barrier in Asia. Notably, roughly 20% of the A/H7N9-infected patients succumbed to the zoonotic infection whereas two of three A/H10N8 human infections were also lethal. Thus, these events revived the concerns of potential pandemic threats by AIVs in the horizon. This article reviews the various human incursions with AIV variants and provides insight on how continued circulation of these viruses poses perpetual challenge to global public health. As the world anticipates for the next human pandemic, constant vigilance for newly emerging viruses in nature is highly encouraged. With the various numbers of AIVs demonstrating their capacity to breach the animal-human host interface and apparent limitations of current antivirals, there is a need to broaden the selection of pre-pandemic vaccine candidate viruses and development of novel alternative therapeutic strategies. PMID:25003087

  11. Adaptation of Pandemic H2N2 Influenza A Viruses in Humans

    PubMed Central

    Joseph, Udayan; Linster, Martin; Suzuki, Yuka; Krauss, Scott; Halpin, Rebecca A.; Vijaykrishna, Dhanasekaran; Fabrizio, Thomas P.; Bestebroer, Theo M.; Maurer-Stroh, Sebastian; Webby, Richard J.; Wentworth, David E.; Fouchier, Ron A. M.

    2014-01-01

    The 1957 A/H2N2 influenza virus caused an estimated 2 million fatalities during the pandemic. Since viruses of the H2 subtype continue to infect avian species and pigs, the threat of reintroduction into humans remains. To determine factors involved in the zoonotic origin of the 1957 pandemic, we performed analyses on genetic sequences of 175 newly sequenced human and avian H2N2 virus isolates and all publicly available influenza virus genomes. PMID:25505070

  12. Isolation and genetic characterization of avian-like H1N1 and novel ressortant H1N2 influenza viruses from pigs in China.

    PubMed

    Yu, Hai; Zhang, Peng-Chao; Zhou, Yan-Jun; Li, Guo-Xin; Pan, Jie; Yan, Li-Ping; Shi, Xiao-Xiao; Liu, Hui-Li; Tong, Guang-Zhi

    2009-08-21

    As pigs are susceptible to both human and avian influenza viruses, they have been proposed to be intermediate hosts or mixing vessels for the generation of pandemic influenza viruses through reassortment or adaptation to the mammalian host. In this study, we reported avian-like H1N1 and novel ressortant H1N2 influenza viruses from pigs in China. Homology and phylogenetic analyses showed that the H1N1 virus (A/swine/Zhejiang/1/07) was closely to avian-like H1N1 viruses and seemed to be derived from the European swine H1N1 viruses, which was for the first time reported in China; and the two H1N2 viruses (A/swine/Shanghai/1/07 and A/swine/Guangxi/13/06) were novel ressortant H1N2 influenza viruses containing genes from the classical swine (HA, NP, M and NS), human (NA and PB1) and avian (PB2 and PA) lineages, which indicted that the reassortment among human, avian, and swine influenza viruses had taken place in pigs in China and resulted in the generation of new viruses. The isolation of avian-like H1N1 influenza virus originated from the European swine H1N1 viruses, especially the emergence of two novel ressortant H1N2 influenza viruses provides further evidence that pigs serve as intermediate hosts or "mixing vessels", and swine influenza virus surveillance in China should be given a high priority.

  13. Susceptibility of avian species to North American H13 low pathogenic avian influenza viruses.

    PubMed

    Brown, Justin; Poulson, Rebecca; Carter, Deborah; Lebarbenchon, Camille; Pantin-Jackwood, Mary; Spackman, Erica; Shepherd, Eric; Killian, Mary; Stallknecht, David

    2012-12-01

    Gulls are widely recognized reservoirs for low pathogenic avian influenza (LPAI) viruses; however, the subtypes maintained in these populations and/or the transmission mechanisms involved are poorly understood. Although, a wide diversity of influenza viruses have been isolated from gulls, two hemagglutinin subtypes (H13 and H16) are rarely detected in other avian groups, and existing surveillance data suggests they are maintained almost exclusively within gull populations. In order to evaluate the host range of these gull-adapted influenza subtypes and to characterize viral infection in the gull host, we conducted a series of challenge experiments, with multiple North American strains of H13 LPAI virus in ring-billed gulls (Larus delawarensis), mallards (Anas platyrhynchos), chickens (Gallus domesticus), and turkeys (Meleagris gallopavo). The susceptibility to H13 LPAI viruses varied between species and viral strain. Gulls were highly susceptible to H13 LPAI virus infection and excreted virus via the oropharynx and cloaca for several days. The quantity and duration of shedding was similar between the two routes. Turkeys and ducks were resistant to infection with most strains of H13 LPAI virus, but low numbers of inoculated birds were infected after challenge with specific viral strains. Chickens were refractory to infection with all strains of H13 LPAI virus they were challenged with. The experimental results presented herein are consistent with existing surveillance data on H13 LPAI viruses in birds, and indicate that influenza viruses of the H13 subtype are strongly host-adapted to gulls, but rare spill-over into aberrant hosts (i.e., turkeys and ducks) can occur.

  14. Proposed lead molecules against Hemagglutinin of avian influenza virus (H5N1)

    PubMed Central

    Nandi, Tannistha

    2008-01-01

    Human infection with avian influenza H5N1 is an emerging infectious disease characterized by respiratory symptoms and a high fatality rate. Hemagglutinin and neuraminidase are the two surface proteins responsible for infection by influenza virus. Till date, neuraminidase has been the major target for antiviral drugs. In the present study we chose hemagglutinin protein as it mediates the binding of the virus to target cells through sialic acid residues on the host cell-surface. Hemagglutinin of H5 avian influenza (PDB ID: 1JSN) was used as the receptor protein. Ligands were generated by structure-based de novo approach and virtual screening of ZINC database. A total of 11,104 conformers were generated and docked into the receptor binding site using ‘High Throughput Virtual Screening’. We proposed potential lead molecules against the receptor binding site of hemagglutinin based on the results obtained from in silico docking and hydrogen bond interaction between the ligand and the 1JSN protein molecule. We found sialic acid derivative 1 to be the lead molecules amongst the ligands generated by structure based de novo approach. However the molecules obtained from ZINC database were showing better docking scores as well as conserved hydrogen bond interactions. Thus we proposed ZINC00487720 and ZINC00046810 as potential lead molecules that could be used as an inhibitor to the receptor binding site of hemagglutinin. They could now be studied in vivo to validate the in silico results. PMID:18317572

  15. Persistence of Avian Influenza Viruses in Lake Sediment, Duck Feces, and Duck Meat ▿ †

    PubMed Central

    Nazir, Jawad; Haumacher, Renate; Ike, Anthony C.; Marschang, Rachel E.

    2011-01-01

    The persistence of 3 low-pathogenicity avian influenza viruses (LPAIV) (H4N6, H5N1, and H6N8) and one human influenza virus (H1N1) as well as Newcastle disease virus (NDV) and enteric cytopathogenic bovine orphan (ECBO) virus was investigated in lake sediment, duck feces, and duck meat at 30, 20, 10, and 0°C using a germ carrier technique. Virus-loaded germ carriers were incubated in each substrate, and residual infectivity of the eluted virus was quantified on cell culture after regular intervals for a maximum of 24 weeks. Data were analyzed by a linear regression model to calculate T90 values (time required for 90% loss of virus infectivity) and estimated persistence of the viruses. In general, the persistence of all of the viruses was highest in lake sediment, followed by feces, and was the lowest in duck meat at all temperatures. For the avian influenza virus subtypes, T90 values in sediment ranged from 5 to 11, 13 to 18, 43 to 54, and 66 to 394 days at 30, 20, 10, and 0°C, respectively, which were 2 to 5 times higher than the T90 values of the viruses in the feces and meat. Although the individual viruses vary in tenacity, the survival time of influenza viruses was shorter than that of NDV and ECBO virus in all substrates. The results of this study suggest that lake sediment may act as a long-term source of influenza viruses in the aquatic habitat, while the viruses may remain infectious for extended periods of time in duck feces and meat at low temperatures, allowing persistence of the viruses in the environment over winter. PMID:21622783

  16. Phylogenetic Analysis and Pathogenicity Assessment of Two Strains of Avian Influenza Virus Subtype H9N2 Isolated from Migratory Birds: High Homology of Internal Genes with Human H10N8 Virus.

    PubMed

    Ye, Ge; Liang, Chai Hong; Hua, Deng Guo; Song, Lei Yong; Xiang, Yang Guo; Guang, Chen; Lan, Chen Hua; Ping, Hua Yu

    2016-01-01

    Two human-infecting avian influenza viruses (AIVs), H7N9 and H10N8, have emerged in China, which further indicate that the H9N2 subtype of AIVs, as an internal gene donor, may have an important role in the generation of new viruses with cross-species transmissibility and pathogenicity. H9N2 viruses that contain such internal genes widely exist in poultry but are rarely reported in migratory birds. In this study, two strains of the H9N2 virus were isolated from fecal samples of migratory birds in 2014: one strain from Caizi Lake in Anhui Province and one from Chen Lake in Hubei Province of China. Nucleotide sequence analysis revealed high homology of all six internal genes of these two strains with the internal genes of the human H10N8 virus in Jiangxi Province, as well as with the human H7N9 virus. Phylogenetic analysis indicated a possible origin of these two strains from poultry in South China. Both of the two viruses tested could replicated in respiratory organs of infective mice without adaption, by both strains of the H9N2 AIVs from wild birds, suggesting their potential capacity for directly infecting mammals. Our findings indicate the existence of H9N2 viruses that contain internal genes highly homologous with human H10N8 or H7N9 viruses. Wild birds can contribute to the spread of the H9N2 virus that contains the "harmful" internal gene complex, leading to gene rearrangement with other influenza viruses and to the generation of new pathogenic viruses. Therefore, strengthening AIV surveillance in wild birds can promote an understanding of the presence and prevalence of viruses and provide scientific evidence for the prevention and control of AIVs and human-infecting AIVs. PMID:26973600

  17. Phylogenetic Analysis and Pathogenicity Assessment of Two Strains of Avian Influenza Virus Subtype H9N2 Isolated from Migratory Birds: High Homology of Internal Genes with Human H10N8 Virus

    PubMed Central

    Ye, Ge; Liang, Chai Hong; Hua, Deng Guo; Song, Lei Yong; Xiang, Yang Guo; Guang, Chen; Lan, Chen Hua; Ping, Hua Yu

    2016-01-01

    Two human-infecting avian influenza viruses (AIVs), H7N9 and H10N8, have emerged in China, which further indicate that the H9N2 subtype of AIVs, as an internal gene donor, may have an important role in the generation of new viruses with cross-species transmissibility and pathogenicity. H9N2 viruses that contain such internal genes widely exist in poultry but are rarely reported in migratory birds. In this study, two strains of the H9N2 virus were isolated from fecal samples of migratory birds in 2014: one strain from Caizi Lake in Anhui Province and one from Chen Lake in Hubei Province of China. Nucleotide sequence analysis revealed high homology of all six internal genes of these two strains with the internal genes of the human H10N8 virus in Jiangxi Province, as well as with the human H7N9 virus. Phylogenetic analysis indicated a possible origin of these two strains from poultry in South China. Both of the two viruses tested could replicated in respiratory organs of infective mice without adaption, by both strains of the H9N2 AIVs from wild birds, suggesting their potential capacity for directly infecting mammals. Our findings indicate the existence of H9N2 viruses that contain internal genes highly homologous with human H10N8 or H7N9 viruses. Wild birds can contribute to the spread of the H9N2 virus that contains the “harmful” internal gene complex, leading to gene rearrangement with other influenza viruses and to the generation of new pathogenic viruses. Therefore, strengthening AIV surveillance in wild birds can promote an understanding of the presence and prevalence of viruses and provide scientific evidence for the prevention and control of AIVs and human-infecting AIVs. PMID:26973600

  18. Phylogenetic Analysis and Pathogenicity Assessment of Two Strains of Avian Influenza Virus Subtype H9N2 Isolated from Migratory Birds: High Homology of Internal Genes with Human H10N8 Virus.

    PubMed

    Ye, Ge; Liang, Chai Hong; Hua, Deng Guo; Song, Lei Yong; Xiang, Yang Guo; Guang, Chen; Lan, Chen Hua; Ping, Hua Yu

    2016-01-01

    Two human-infecting avian influenza viruses (AIVs), H7N9 and H10N8, have emerged in China, which further indicate that the H9N2 subtype of AIVs, as an internal gene donor, may have an important role in the generation of new viruses with cross-species transmissibility and pathogenicity. H9N2 viruses that contain such internal genes widely exist in poultry but are rarely reported in migratory birds. In this study, two strains of the H9N2 virus were isolated from fecal samples of migratory birds in 2014: one strain from Caizi Lake in Anhui Province and one from Chen Lake in Hubei Province of China. Nucleotide sequence analysis revealed high homology of all six internal genes of these two strains with the internal genes of the human H10N8 virus in Jiangxi Province, as well as with the human H7N9 virus. Phylogenetic analysis indicated a possible origin of these two strains from poultry in South China. Both of the two viruses tested could replicated in respiratory organs of infective mice without adaption, by both strains of the H9N2 AIVs from wild birds, suggesting their potential capacity for directly infecting mammals. Our findings indicate the existence of H9N2 viruses that contain internal genes highly homologous with human H10N8 or H7N9 viruses. Wild birds can contribute to the spread of the H9N2 virus that contains the "harmful" internal gene complex, leading to gene rearrangement with other influenza viruses and to the generation of new pathogenic viruses. Therefore, strengthening AIV surveillance in wild birds can promote an understanding of the presence and prevalence of viruses and provide scientific evidence for the prevention and control of AIVs and human-infecting AIVs.

  19. Contemporary Avian Influenza A Virus Subtype H1, H6, H7, H10, and H15 Hemagglutinin Genes Encode a Mammalian Virulence Factor Similar to the 1918 Pandemic Virus H1 Hemagglutinin

    PubMed Central

    Qi, Li; Pujanauski, Lindsey M.; Davis, A. Sally; Schwartzman, Louis M.; Chertow, Daniel S.; Baxter, David; Scherler, Kelsey; Hartshorn, Kevan L.; Slemons, Richard D.; Walters, Kathie-Anne; Kash, John C.

    2014-01-01

    ABSTRACT Zoonotic avian influenza virus infections may lead to epidemics or pandemics. The 1918 pandemic influenza virus has an avian influenza virus-like genome, and its H1 hemagglutinin was identified as a key mammalian virulence factor. A chimeric 1918 virus expressing a contemporary avian H1 hemagglutinin, however, displayed murine pathogenicity indistinguishable from that of the 1918 virus. Here, isogenic chimeric avian influenza viruses were constructed on an avian influenza virus backbone, differing only by hemagglutinin subtype expressed. Viruses expressing the avian H1, H6, H7, H10, and H15 subtypes were pathogenic in mice and cytopathic in normal human bronchial epithelial cells, in contrast to H2-, H3-, H5-, H9-, H11-, H13-, H14-, and H16-expressing viruses. Mouse pathogenicity was associated with pulmonary macrophage and neutrophil recruitment. These data suggest that avian influenza virus hemagglutinins H1, H6, H7, H10, and H15 contain inherent mammalian virulence factors and likely share a key virulence property of the 1918 virus. Consequently, zoonotic infections with avian influenza viruses bearing one of these hemagglutinins may cause enhanced disease in mammals. PMID:25406382

  20. Fatal H5N6 Avian Influenza Virus Infection in a Domestic Cat and Wild Birds in China.

    PubMed

    Yu, Zhijun; Gao, Xiaolong; Wang, Tiecheng; Li, Yanbing; Li, Yongcheng; Xu, Yu; Chu, Dong; Sun, Heting; Wu, Changjiang; Li, Shengnan; Wang, Haijun; Li, Yuanguo; Xia, Zhiping; Lin, Weishi; Qian, Jun; Chen, Hualan; Xia, Xianzhu; Gao, Yuwei

    2015-01-01

    H5N6 avian influenza viruses (AIVs) may pose a potential human risk as suggested by the first documented naturally-acquired human H5N6 virus infection in 2014. Here, we report the first cases of fatal H5N6 avian influenza virus (AIV) infection in a domestic cat and wild birds. These cases followed human H5N6 infections in China and preceded an H5N6 outbreak in chickens. The extensive migration routes of wild birds may contribute to the geographic spread of H5N6 AIVs and pose a risk to humans and susceptible domesticated animals, and the H5N6 AIVs may spread from southern China to northern China by wild birds. Additional surveillance is required to better understand the threat of zoonotic transmission of AIVs.

  1. Characterization of Avian Influenza and Newcastle Disease Viruses from Poultry in Libya.

    PubMed

    Kammon, Abdulwahab; Heidari, Alireza; Dayhum, Abdunaser; Eldaghayes, Ibrahim; Sharif, Monier; Monne, Isabela; Cattoli, Giovanni; Asheg, Abdulatif; Farhat, Milad; Kraim, Elforjani

    2015-09-01

    On March 2013, the Libyan poultry industry faced severe outbreaks due to mixed infections of APMV-1 (Newcastle disease) and low pathogenic avian influenza (AI) of the H9N2 subtype which were causing high mortality and great economic losses. APMV-1 and H9N2 were isolated and characterized. Genetic sequencing of the APMV-1/chicken/Libya/13VIR/ 7225-1/2013 isolate revealed the presence of a velogenic APMV-1 belonging to lineage 5 (GRRRQKR*F Lin.5) or genotype VII in class II, according to the nomenclature in use. Three AI viruses of the H9N2 subtype, namely A/avian/Libya/13VIR7225-2/2013, A/avian/Libya/13VIR7225-3/2013, and A/avian/Libya/13VIR7225-5/2013, were isolated and found to belong to the G1 lineage. Analysis of amino acid sequences showed that the analyzed H9N2 viruses contained the amino acid Leu at position 226 (H3 numbering) at the receptor binding site of the HA, responsible for human virus-like receptor specificity. On March 2014, an outbreak of highly pathogenic avian influenza (HPAI) virus of the H5N1 subtype was diagnosed in a backyard poultry farm in an eastern region of Libya. The H5N1 isolate (A/chicken/Libya/14VIR2749-16/2014) was detected by real time RT-PCR (rRT-PCR). Genetic characterization of the HA gene revealed that the identified subtype was highly pathogenic, belonged to the 2.2.1 lineage, and clustered with recent Egyptian viruses. This study revealed the presence of a velogenic APMV-1 genotype and of two influenza subtypes, namely HPAI H5N1 and H9N2, which are of major interest for public and animal health. Considering these findings, more investigations must be undertaken to establish and implement adequate influenza surveillance programs; this would allow better study of the epidemiology of APMV-1 genotype VII in Libya and evaluation of the current vaccination strategies. PMID:26478162

  2. Characterization of Avian Influenza and Newcastle Disease Viruses from Poultry in Libya.

    PubMed

    Kammon, Abdulwahab; Heidari, Alireza; Dayhum, Abdunaser; Eldaghayes, Ibrahim; Sharif, Monier; Monne, Isabela; Cattoli, Giovanni; Asheg, Abdulatif; Farhat, Milad; Kraim, Elforjani

    2015-09-01

    On March 2013, the Libyan poultry industry faced severe outbreaks due to mixed infections of APMV-1 (Newcastle disease) and low pathogenic avian influenza (AI) of the H9N2 subtype which were causing high mortality and great economic losses. APMV-1 and H9N2 were isolated and characterized. Genetic sequencing of the APMV-1/chicken/Libya/13VIR/ 7225-1/2013 isolate revealed the presence of a velogenic APMV-1 belonging to lineage 5 (GRRRQKR*F Lin.5) or genotype VII in class II, according to the nomenclature in use. Three AI viruses of the H9N2 subtype, namely A/avian/Libya/13VIR7225-2/2013, A/avian/Libya/13VIR7225-3/2013, and A/avian/Libya/13VIR7225-5/2013, were isolated and found to belong to the G1 lineage. Analysis of amino acid sequences showed that the analyzed H9N2 viruses contained the amino acid Leu at position 226 (H3 numbering) at the receptor binding site of the HA, responsible for human virus-like receptor specificity. On March 2014, an outbreak of highly pathogenic avian influenza (HPAI) virus of the H5N1 subtype was diagnosed in a backyard poultry farm in an eastern region of Libya. The H5N1 isolate (A/chicken/Libya/14VIR2749-16/2014) was detected by real time RT-PCR (rRT-PCR). Genetic characterization of the HA gene revealed that the identified subtype was highly pathogenic, belonged to the 2.2.1 lineage, and clustered with recent Egyptian viruses. This study revealed the presence of a velogenic APMV-1 genotype and of two influenza subtypes, namely HPAI H5N1 and H9N2, which are of major interest for public and animal health. Considering these findings, more investigations must be undertaken to establish and implement adequate influenza surveillance programs; this would allow better study of the epidemiology of APMV-1 genotype VII in Libya and evaluation of the current vaccination strategies.

  3. Neuraminidase hemadsorption activity, conserved in avian influenza A viruses, does not influence viral replication in ducks.

    PubMed Central

    Kobasa, D; Rodgers, M E; Wells, K; Kawaoka, Y

    1997-01-01

    The N1 and N9 neuraminidase (NA) subtypes of influenza A viruses exhibit significant hemadsorption activity that localizes to a site distinct from that of the enzymatic active site. To determine the conservation of hemadsorption activity among different NAs, we have examined most of the NA subtypes from avian, swine, equine, and human virus isolates. All subtypes of avian virus NAs examined and one equine virus N8 NA possessed high levels of hemadsorption activity. A swine virus N1 NA exhibited only weak hemadsorption activity, while in human virus N1 and N2 NAs, the activity was detected at a much lower level than in avian virus NAs. NAs which possessed hemadsorption activity for chicken erythrocytes (RBCs) were similarly able to adsorb human RBCs. However, none of the hemadsorption-positive NAs could bind equine, swine, or bovine RBCs, suggesting that RBCs from these species lack molecules, recognized by the NA hemadsorption site, present on human and chicken RBCs. Mutagenesis of the putative hemadsorption site of A/duck/Hong Kong/7/75 N2 NA abolished the high level of hemadsorption activity exhibited by the wild-type protein but also resulted in a 50% reduction of the NA enzymatic activity. A transfectant virus, generated by reverse genetics, containing this mutated NA replicated 10-fold less efficiently in chicken embryo fibroblast cultures than did a transfectant virus expressing the wild-type NA. However, both viruses replicated equally well in Peking ducks. Although conservation of NA hemadsorption activity among avian virus NAs suggests the maintenance of a required function of NA, loss of the activity does not preclude the replication of the virus in an avian host. PMID:9261394

  4. Highly pathogenic avian influenza viruses and generation of novel reassortants,United States, 2014–2015

    USGS Publications Warehouse

    Dong-Hun Lee,; Justin Bahl,; Mia Kim Torchetti,; Mary Lea Killian,; Ip, Hon S.; David E Swayne,

    2016-01-01

    Asian highly pathogenic avian influenza A(H5N8) viruses spread into North America in 2014 during autumn bird migration. Complete genome sequencing and phylogenetic analysis of 32 H5 viruses identified novel H5N1, H5N2, and H5N8 viruses that emerged in late 2014 through reassortment with North American low-pathogenicity avian influenza viruses.

  5. The new World Organisation for Animal Health standards on avian influenza and international trade.

    PubMed

    Thiermann, Alex B

    2007-03-01

    In 2002, the World Organisation for Animal Health began a review of the chapter on avian influenza by convening a group of experts to revise the most recent scientific literature. The group drafted the initial text that would provide the necessary recommendations on avian influenza control and prevention measures. The main objectives of this draft were to provide clear notification criteria, as well as commodity-specific, risk-based mitigating measures, that would provide safety when trading and encourage transparent reporting.

  6. Highly Pathogenic Avian Influenza Viruses and Generation of Novel Reassortants, United States, 2014–2015

    PubMed Central

    Lee, Dong-Hun; Bahl, Justin; Torchetti, Mia Kim; Killian, Mary Lea; Ip, Hon S.; DeLiberto, Thomas J.

    2016-01-01

    Asian highly pathogenic avian influenza A(H5N8) viruses spread into North America in 2014 during autumn bird migration. Complete genome sequencing and phylogenetic analysis of 32 H5 viruses identified novel H5N1, H5N2, and H5N8 viruses that emerged in late 2014 through reassortment with North American low-pathogenicity avian influenza viruses. PMID:27314845

  7. Highly Pathogenic Avian Influenza Viruses and Generation of Novel Reassortants, United States, 2014-2015.

    PubMed

    Lee, Dong-Hun; Bahl, Justin; Torchetti, Mia Kim; Killian, Mary Lea; Ip, Hon S; DeLiberto, Thomas J; Swayne, David E

    2016-07-01

    Asian highly pathogenic avian influenza A(H5N8) viruses spread into North America in 2014 during autumn bird migration. Complete genome sequencing and phylogenetic analysis of 32 H5 viruses identified novel H5N1, H5N2, and H5N8 viruses that emerged in late 2014 through reassortment with North American low-pathogenicity avian influenza viruses. PMID:27314845

  8. Antibodies against avian-like A (H1N1) swine influenza virus among swine farm residents in eastern China.

    PubMed

    Yin, Xiuchen; Yin, Xin; Rao, Baizhong; Xie, Chunfang; Zhang, Pengchao; Qi, Xian; Wei, Ping; Liu, Huili

    2014-04-01

    In 2007, the avian-like H1N1 virus (A/swine/Zhejiang/1/07) was first isolated in pigs in China. Recently, it was reported that a 3-year-old boy was infected with avian-like A (H1N1) swine influenza virus (SIV) in Jiangsu Province, China. To investigate the prevalence of avian-like A (H1N1) SIV infection among swine farm residents in eastern China, an active influenza surveillance program was conducted on swine farms in this region from May 21, 2010 through April 22, 2012. A total of 1,162 participants were enrolled, including 1,136 persons from 48 pig farms, as well as 26 pig farm veterinarians. A total of 10.7% and 7.8% swine farm residents were positive for antibodies against avian-like A (H1N1) SIV by HI and NT assay, respectively, using 40 as the cut-off antibody titer. Meanwhile, all the serum samples collected from a control of healthy city residents were negative against avian-like A (H1N1) SIV. As the difference in numbers of antibody positive samples between the swine farm residents and health city residents controls was statistically significant (P = 0.002), these data suggest that occupational exposure to pigs may increase swine farm residents' and veterinarians' risk of avian-like A (H1N1) SIV infection in eastern China. This study provides the first data on avian-like A (H1N1) SIV infections in humans in China; the potential for avian-like A (H1N1) SIV entering the human population should also be taken into consideration.

  9. Genesis of avian influenza H9N2 in Bangladesh.

    PubMed

    Shanmuganatham, Karthik; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Alam, SMRabiul; Hasan, MKamrul; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

    2014-12-01

    Avian influenza subtype H9N2 is endemic in many bird species in Asia and the Middle East and has contributed to the genesis of H5N1, H7N9 and H10N8, which are potential pandemic threats. H9N2 viruses that have spread to Bangladesh have acquired multiple gene segments from highly pathogenic (HP) H7N3 viruses that are presumably in Pakistan and currently cocirculate with HP H5N1. However, the source and geographic origin of these H9N2 viruses are not clear. We characterized the complete genetic sequences of 37 Bangladeshi H9N2 viruses isolated in 2011-2013 and investigated their inter- and intrasubtypic genetic diversities by tracing their genesis in relationship to other H9N2 viruses isolated from neighboring countries. H9N2 viruses in Bangladesh are homogenous with several mammalian host-specific markers and are a new H9N2 sublineage wherein the hemagglutinin (HA) gene is derived from an Iranian H9N2 lineage (Mideast_B Iran), the neuraminidase (NA) and polymerase basic 2 (PB2) genes are from Dubai H9N2 (Mideast_C Dubai), and the non-structural protein (NS), nucleoprotein (NP), matrix protein (MP), polymerase acidic (PA) and polymerase basic 1 (PB1) genes are from HP H7N3 originating from Pakistan. Different H9N2 genotypes that were replaced in 2006 and 2009 by other reassortants have been detected in Bangladesh. Phylogenetic and molecular analyses suggest that the current genotype descended from the prototypical H9N2 lineage (G1), which circulated in poultry in China during the late 1990s and came to Bangladesh via the poultry trade within the Middle East, and that this genotype subsequently reassorted with H7N3 and H9N2 lineages from Pakistan and spread throughout India. Thus, continual surveillance of Bangladeshi HP H5N1, H7N3 and H9N2 is warranted to identify further evolution and adaptation to humans. PMID:26038507

  10. Genesis of avian influenza H9N2 in Bangladesh

    PubMed Central

    Shanmuganatham, Karthik; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Alam, SMRabiul; Hasan, MKamrul; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

    2014-01-01

    Avian influenza subtype H9N2 is endemic in many bird species in Asia and the Middle East and has contributed to the genesis of H5N1, H7N9 and H10N8, which are potential pandemic threats. H9N2 viruses that have spread to Bangladesh have acquired multiple gene segments from highly pathogenic (HP) H7N3 viruses that are presumably in Pakistan and currently cocirculate with HP H5N1. However, the source and geographic origin of these H9N2 viruses are not clear. We characterized the complete genetic sequences of 37 Bangladeshi H9N2 viruses isolated in 2011–2013 and investigated their inter- and intrasubtypic genetic diversities by tracing their genesis in relationship to other H9N2 viruses isolated from neighboring countries. H9N2 viruses in Bangladesh are homogenous with several mammalian host-specific markers and are a new H9N2 sublineage wherein the hemagglutinin (HA) gene is derived from an Iranian H9N2 lineage (Mideast_B Iran), the neuraminidase (NA) and polymerase basic 2 (PB2) genes are from Dubai H9N2 (Mideast_C Dubai), and the non-structural protein (NS), nucleoprotein (NP), matrix protein (MP), polymerase acidic (PA) and polymerase basic 1 (PB1) genes are from HP H7N3 originating from Pakistan. Different H9N2 genotypes that were replaced in 2006 and 2009 by other reassortants have been detected in Bangladesh. Phylogenetic and molecular analyses suggest that the current genotype descended from the prototypical H9N2 lineage (G1), which circulated in poultry in China during the late 1990s and came to Bangladesh via the poultry trade within the Middle East, and that this genotype subsequently reassorted with H7N3 and H9N2 lineages from Pakistan and spread throughout India. Thus, continual surveillance of Bangladeshi HP H5N1, H7N3 and H9N2 is warranted to identify further evolution and adaptation to humans. PMID:26038507

  11. Genesis of avian influenza H9N2 in Bangladesh.

    PubMed

    Shanmuganatham, Karthik; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Alam, SMRabiul; Hasan, MKamrul; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

    2014-12-01

    Avian influenza subtype H9N2 is endemic in many bird species in Asia and the Middle East and has contributed to the genesis of H5N1, H7N9 and H10N8, which are potential pandemic threats. H9N2 viruses that have spread to Bangladesh have acquired multiple gene segments from highly pathogenic (HP) H7N3 viruses that are presumably in Pakistan and currently cocirculate with HP H5N1. However, the source and geographic origin of these H9N2 viruses are not clear. We characterized the complete genetic sequences of 37 Bangladeshi H9N2 viruses isolated in 2011-2013 and investigated their inter- and intrasubtypic genetic diversities by tracing their genesis in relationship to other H9N2 viruses isolated from neighboring countries. H9N2 viruses in Bangladesh are homogenous with several mammalian host-specific markers and are a new H9N2 sublineage wherein the hemagglutinin (HA) gene is derived from an Iranian H9N2 lineage (Mideast_B Iran), the neuraminidase (NA) and polymerase basic 2 (PB2) genes are from Dubai H9N2 (Mideast_C Dubai), and the non-structural protein (NS), nucleoprotein (NP), matrix protein (MP), polymerase acidic (PA) and polymerase basic 1 (PB1) genes are from HP H7N3 originating from Pakistan. Different H9N2 genotypes that were replaced in 2006 and 2009 by other reassortants have been detected in Bangladesh. Phylogenetic and molecular analyses suggest that the current genotype descended from the prototypical H9N2 lineage (G1), which circulated in poultry in China during the late 1990s and came to Bangladesh via the poultry trade within the Middle East, and that this genotype subsequently reassorted with H7N3 and H9N2 lineages from Pakistan and spread throughout India. Thus, continual surveillance of Bangladeshi HP H5N1, H7N3 and H9N2 is warranted to identify further evolution and adaptation to humans.

  12. Genetic diversity of avian influenza A (H10N8) virus in live poultry markets and its association with human infections in China.

    PubMed

    Liu, Mingbin; Li, Xiaodan; Yuan, Hui; Zhou, Jianfang; Wu, Jingwen; Bo, Hong; Xia, Wen; Xiong, Ying; Yang, Lei; Gao, Rongbao; Guo, Junfeng; Huang, Weijuan; Zhang, Ye; Zhao, Xiang; Zou, Xiaohui; Chen, Tao; Wang, Dayan; Li, Qun; Wang, ShiWen; Chen, Shengen; Hu, Maohong; Ni, Xiansheng; Gong, Tian; Shi, Yong; Li, Jianxiong; Zhou, Jun; Cai, Jun; Xiao, Zuke; Zhang, Wei; Sun, Jian; Li, Dexin; Wu, Guizhen; Feng, Zijian; Wang, Yu; Chen, Haiying; Shu, Yuelong

    2015-01-15

    Following the first human infection with the influenza A (H10N8) virus in Nanchang, China in December 2013, we identified two additional patients on January 19 and February 9, 2014. The epidemiologic, clinical, and virological data from the patients and the environmental specimen collected from 23 local live poultry markets (LPMs) were analyzed. The three H10N8 cases had a history of poultry exposure and presented with high fever (>38°C), rapidly progressive pneumonia and lymphopenia. Substantial high levels of cytokines and chemokines were observed. The sequences from an isolate (A/Environment/Jiangxi/03489/2013 [H10N8]) in an epidemiologically linked LPM showed highly identity with human H10N8 virus, evidencing LPM as the source of human infection. The HA and NA of human and environmental H10N8 isolates showed high identity (99.1-99.9%) while six genotypes with internal genes derived from H9N2, H7N3 and H7N9 subtype viruses were detected in environmental H10N8 isolates. The genotype of the virus causing human infection, Jiangxi/346, possessed a whole internal gene set of the A/Environment/Jiangxi/10618/2014(H9N2)-like virus. Thus, our findings support the notion that LPMs can act as both a gene pool for the generation of novel reassortants and a source for human infection, and intensive surveillance and management should therefore be conducted.

  13. Scale-Free Distribution of Avian Influenza Outbreaks

    NASA Astrophysics Data System (ADS)

    Small, Michael; Walker, David M.; Tse, Chi Kong

    2007-11-01

    Using global case data for the period from 25 November 2003 to 10 March 2007, we construct a network of plausible transmission pathways for the spread of avian influenza among domestic and wild birds. The network structure we obtain is complex and exhibits scale-free (although not necessarily small-world) properties. Communities within this network are connected with a distribution of links with infinite variance. Hence, the disease transmission model does not exhibit a threshold and so the infection will continue to propagate even with very low transmissibility. Consequentially, eradication with methods applicable to locally homogeneous populations is not possible. Any control measure needs to focus explicitly on the hubs within this network structure.

  14. Inactivation of avian influenza virus using common detergents and chemicals.

    PubMed

    Lombardi, M E; Ladman, B S; Alphin, R L; Benson, E R

    2008-03-01

    Six disinfectant chemicals were tested individually for effectiveness against low pathogenic avian influenza virus (LPAIV) A/H7N2/Chick/MinhMa/04. The tested agents included acetic acid (C2H4O2), citric acid (C6H8O7), calcium hypochlorite (Ca(ClO)2), sodium hypochlorite (NaOCl), a powdered laundry detergent with peroxygen (bleach), and a commercially available iodine/acid disinfectant. Four of the six chemicals, including acetic acid (5%), citric acid (1% and 3%), calcium hypochlorite (750 ppm), and sodium hypochlorite (750 ppm) effectively inactivated LPAIV on hard and nonporous surfaces. The conventional laundry detergent was tested at multiple concentrations and found to be suitable for inactivating LPAIV on hard and nonporous surfaces at 6 g/L. Only citric acid and commercially available iodine/acid disinfectant were found to be effective at inactivating LPAIV on both porous and nonporous surfaces.

  15. 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. PMID:26683184

  16. Highly Pathogenic Avian Influenza Virus among Wild Birds in Mongolia

    PubMed Central

    Gilbert, Martin; Jambal, Losolmaa; Karesh, William B.; Fine, Amanda; Shiilegdamba, Enkhtuvshin; Dulam, Purevtseren; Sodnomdarjaa, Ruuragchaa; Ganzorig, Khuukhenbaatar; Batchuluun, Damdinjav; Tseveenmyadag, Natsagdorj; Bolortuya, Purevsuren; Cardona, Carol J.; Leung, Connie Y. H.; Peiris, J. S. Malik; Spackman, Erica; Swayne, David E.; Joly, Damien O.

    2012-01-01

    Mongolia combines a near absence of domestic poultry, with an abundance of migratory waterbirds, to create an ideal location to study the epidemiology of highly pathogenic avian influenza virus (HPAIV) in a purely wild bird system. Here we present the findings of active and passive surveillance for HPAIV subtype H5N1 in Mongolia from 2005–2011, together with the results of five outbreak investigations. In total eight HPAIV outbreaks were confirmed in Mongolia during this period. Of these, one was detected during active surveillance employed by this project, three by active surveillance performed by Mongolian government agencies, and four through passive surveillance. A further three outbreaks were recorded in the neighbouring Tyva Republic of Russia on a lake that bisects the international border. No HPAIV was isolated (cultured) from 7,855 environmental fecal samples (primarily from ducks), or from 2,765 live, clinically healthy birds captured during active surveillance (primarily shelducks, geese and swans), while four HPAIVs were isolated from 141 clinically ill or dead birds located through active surveillance. Two low pathogenic avian influenza viruses (LPAIV) were cultured from ill or dead birds during active surveillance, while environmental feces and live healthy birds yielded 56 and 1 LPAIV respectively. All Mongolian outbreaks occurred in 2005 and 2006 (clade 2.2), or 2009 and 2010 (clade 2.3.2.1); all years in which spring HPAIV outbreaks were reported in Tibet and/or Qinghai provinces in China. The occurrence of outbreaks in areas deficient in domestic poultry is strong evidence that wild birds can carry HPAIV over at least moderate distances. However, failure to detect further outbreaks of clade 2.2 after June 2006, and clade 2.3.2.1 after June 2010 suggests that wild birds migrating to and from Mongolia may not be competent as indefinite reservoirs of HPAIV, or that HPAIV did not reach susceptible populations during our study. PMID:22984464

  17. China's heath care system and avian influenza preparedness.

    PubMed

    Kaufman, Joan A

    2008-02-15

    The severe acute respiratory syndrome crisis exposed serious deficiencies in China's public health system and willingness to report outbreaks of threats to public health. Consequently, China may be one of the weak links in global preparedness for avian influenza. China's rural health care system has been weakened by 20 years of privatization and fiscal decentralization. China plays a huge role in the global poultry industry, with a poultry population of 14 billion birds, 70%-80% of which are reared in backyard conditions. Although surveillance has been strengthened, obstacles to the timely reporting of disease outbreaks still exist. The weakened health care system prevents many sick people from seeking care at a health care facility, where reporting would originate. Inadequate compensation to farmers for culled birds leads to nonreporting, and local officials may be complicit if they suspect that reporting might lead to economic losses for their communities. At the local level, China's crisis-management ability and multisectoral coordination are weak. The poor quality of infection control in many rural facilities is a serious and well-documented problem. However, traditions of community political mobilization suggest that the potential for providing rural citizens with public health information is possible when mandated from the central government. Addressing these issues now and working on capacity issues, authority structures, accountability, and local reporting and control structures will benefit the control of a potential avian influenza outbreak, as well as inevitable outbreaks of other emerging infectious diseases in China's Pearl River Delta or in other densely populated locations of animal husbandry in China. PMID:18269328

  18. Adaptive Evolution and Environmental Durability Jointly Structure Phylodynamic Patterns in Avian Influenza Viruses

    PubMed Central

    Roche, Benjamin; Drake, John M.; Brown, Justin; Stallknecht, David E.; Bedford, Trevor; Rohani, Pejman

    2014-01-01

    Avian influenza viruses (AIVs) have been pivotal to the origination of human pandemic strains. Despite their scientific and public health significance, however, there remains much to be understood about the ecology and evolution of AIVs in wild birds, where major pools of genetic diversity are generated and maintained. Here, we present comparative phylodynamic analyses of human and AIVs in North America, demonstrating (i) significantly higher standing genetic diversity and (ii) phylogenetic trees with a weaker signature of immune escape in AIVs than in human viruses. To explain these differences, we performed statistical analyses to quantify the relative contribution of several potential explanations. We found that HA genetic diversity in avian viruses is determined by a combination of factors, predominantly subtype-specific differences in host immune selective pressure and the ecology of transmission (in particular, the durability of subtypes in aquatic environments). Extending this analysis using a computational model demonstrated that virus durability may lead to long-term, indirect chains of transmission that, when coupled with a short host lifespan, can generate and maintain the observed high levels of genetic diversity. Further evidence in support of this novel finding was found by demonstrating an association between subtype-specific environmental durability and predicted phylogenetic signatures: genetic diversity, variation in phylogenetic tree branch lengths, and tree height. The conclusion that environmental transmission plays an important role in the evolutionary biology of avian influenza viruses—a manifestation of the “storage effect”—highlights the potentially unpredictable impact of wildlife reservoirs for future human pandemics and the need for improved understanding of the natural ecology of these viruses. PMID:25116957

  19. The Genomic Contributions of Avian H1N1 Influenza A Viruses to the Evolution of Mammalian Strains.

    PubMed

    Koçer, Zeynep A; Carter, Robert; Wu, Gang; Zhang, Jinghui; Webster, Robert G

    2015-01-01

    Among the influenza A viruses (IAVs) in wild aquatic birds, only H1, H2, and H3 subtypes have caused epidemics in humans. H1N1 viruses of avian origin have also caused 3 of 5 pandemics. To understand the reappearance of H1N1 in the context of pandemic emergence, we investigated whether avian H1N1 IAVs have contributed to the evolution of human, swine, and 2009 pandemic H1N1 IAVs. On the basis of phylogenetic analysis, we concluded that the polymerase gene segments (especially PB2 and PA) circulating in North American avian H1N1 IAVs have been reintroduced to swine multiple times, resulting in different lineages that led to the emergence of the 2009 pandemic H1N1 IAVs. Moreover, the similar topologies of hemagglutinin and nucleoprotein and neuraminidase and matrix gene segments suggest that each surface glycoprotein coevolved with an internal gene segment within the H1N1 subtype. The genotype of avian H1N1 IAVs of Charadriiformes origin isolated in 2009 differs from that of avian H1N1 IAVs of Anseriformes origin. When the antigenic sites in the hemagglutinin of all 31 North American avian H1N1 IAVs were considered, 60%-80% of the amino acids at the antigenic sites were identical to those in 1918 and/or 2009 pandemic H1N1 viruses. Thus, although the pathogenicity of avian H1N1 IAVs could not be inferred from the phylogeny due to the small dataset, the evolutionary process within the H1N1 IAV subtype suggests that the circulation of H1N1 IAVs in wild birds poses a continuous threat for future influenza pandemics in humans. PMID:26208281

  20. The Genomic Contributions of Avian H1N1 Influenza A Viruses to the Evolution of Mammalian Strains.

    PubMed

    Koçer, Zeynep A; Carter, Robert; Wu, Gang; Zhang, Jinghui; Webster, Robert G

    2015-01-01

    Among the influenza A viruses (IAVs) in wild aquatic birds, only H1, H2, and H3 subtypes have caused epidemics in humans. H1N1 viruses of avian origin have also caused 3 of 5 pandemics. To understand the reappearance of H1N1 in the context of pandemic emergence, we investigated whether avian H1N1 IAVs have contributed to the evolution of human, swine, and 2009 pandemic H1N1 IAVs. On the basis of phylogenetic analysis, we concluded that the polymerase gene segments (especially PB2 and PA) circulating in North American avian H1N1 IAVs have been reintroduced to swine multiple times, resulting in different lineages that led to the emergence of the 2009 pandemic H1N1 IAVs. Moreover, the similar topologies of hemagglutinin and nucleoprotein and neuraminidase and matrix gene segments suggest that each surface glycoprotein coevolved with an internal gene segment within the H1N1 subtype. The genotype of avian H1N1 IAVs of Charadriiformes origin isolated in 2009 differs from that of avian H1N1 IAVs of Anseriformes origin. When the antigenic sites in the hemagglutinin of all 31 North American avian H1N1 IAVs were considered, 60%-80% of the amino acids at the antigenic sites were identical to those in 1918 and/or 2009 pandemic H1N1 viruses. Thus, although the pathogenicity of avian H1N1 IAVs could not be inferred from the phylogeny due to the small dataset, the evolutionary process within the H1N1 IAV subtype suggests that the circulation of H1N1 IAVs in wild birds poses a continuous threat for future influenza pandemics in humans.

  1. 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.

  2. Avian influenza virus isolation, propagation, and titration in embryonated chicken eggs.

    PubMed

    Spackman, Erica; Killian, Mary Lea

    2014-01-01

    Avian influenza virus and some mammalian influenza A viruses are usually isolated, propagated, and titrated in embryonated chicken eggs (ECE). Most any sample type can be accommodated for culture with appropriate processing. Isolation may also be accomplished in cell culture particularly if mammalian lineage isolates are suspected, for example, swine influenza in turkey specimens. Culture is highly sensitive, but is not specific for influenza A, which may be an advantage because a sample may be screened for several agents at once. Once an agent is isolated in culture, the presence of influenza viruses is confirmed with any of several assays. The methods for propagating virus isolates in ECE are described.

  3. Prevalence and diversity of H9N2 avian influenza in chickens of Northern Vietnam, 2014.

    PubMed

    Thuy, Duong Mai; Peacock, Thomas P; Bich, Vu Thi Ngoc; Fabrizio, Thomas; Hoang, Dang Nguyen; Tho, Nguyen Dang; Diep, Nguyen Thi; Nguyen, Minh; Hoa, Le Nguyen Minh; Trang, Hau Thi Thu; Choisy, Marc; Inui, Ken; Newman, Scott; Trung, Nguyen Vu; van Doorn, Rogier; To, Thanh Long; Iqbal, Munir; Bryant, Juliet E

    2016-10-01

    Despite their classification as low pathogenicity avian influenza viruses (LPAIV), A/H9N2 viruses cause significant losses in poultry in many countries throughout Asia, the Middle East and North Africa. To date, poultry surveillance in Vietnam has focused on detection of influenza H5 viruses, and there is limited understanding of influenza H9 epidemiology and transmission dynamics. We determined prevalence and diversity of influenza A viruses in chickens from live bird markets (LBM) of 7 northern Vietnamese provinces, using pooled oropharyngeal swabs collected from October to December 2014. Screening by real time RT-PCR revealed 1207/4900 (24.6%) of pooled swabs to be influenza A virus positive; overall prevalence estimates after accounting for pooling (5 swabs/pools) were 5.8% (CI 5.4-6.0). Subtyping was performed on 468 pooled swabs with M gene Ct<26. No influenza H7 was detected; 422 (90.1%) were H9 positive; and 22 (4.7%) were H5 positive. There was no evidence was of interaction between H9 and H5 virus detection rates. We sequenced 17 whole genomes of A/H9N2, 2 of A/H5N6, and 11 partial genomes. All H9N2 viruses had internal genes that clustered with genotype 57 and were closely related to Chinese human isolates of A/H7N9 and A/H10N8. Using a nucleotide divergence cutoff of 98%, we identified 9 distinct H9 genotypes. Phylogenetic analysis suggested multiple introductions of H9 viruses to northern Vietnam rather than in-situ transmission. Further investigations of H9 prevalence and diversity in other regions of Vietnam are warranted to assess H9 endemicity elsewhere in the country. PMID:27340015

  4. Coexistence of Avian Influenza Virus H10 and H9 Subtypes among Chickens in Live Poultry Markets during an Outbreak of Infection with a Novel H10N8 Virus in Humans in Nanchang, China.

    PubMed

    Hu, Maohong; Li, Xiaodan; Ni, Xiansheng; Wu, Jingwen; Gao, Rongbao; Xia, Wen; Wang, Dayan; He, Fenglan; Chen, Shengen; Liu, Yangqing; Guo, Shuangli; Li, Hui; Shu, Yuelong; Bethel, Jeffrey W; Liu, Mingbin; Moore, Justin B; Chen, Haiying

    2015-01-01

    Infection with the novel H10N8 virus in humans has raised concerns about its pandemic potential worldwide. We report the results of a cross-sectional study of avian influenza viruses (AIVs) in live poultry markets (LPMs) in Nanchang, China, after the first human case of H10N8 virus infection was reported in the city. A total of 201 specimens tested positive for AIVs among 618 samples collected from 24 LPMs in Nanchang from December 2013 to January 2014. We found that the LPMs were heavily contaminated by AIVs, with H9, H10, and H5 being the predominant subtypes and more than half of the LPMs providing samples that were positive for the H10 subtype. Moreover, the coexistence of different subtypes was common in LPMs. Of the 201 positive samples, 20.9% (42/201) had mixed infections with AIVs of different HA subtypes. Of the 42 mixed infections, 50% (21/42) showed the coexistence of the H9 and H10 subtypes, with or without H5, and were from chicken samples. This indicated that the H10N8 virus probably originated from segment reassortment of the H9 and H10 subtypes. PMID:25766608

  5. New England harbor seal H3N8 influenza virus retains avian-like receptor specificity

    PubMed Central

    Hussein, Islam T. M.; Krammer, Florian; Ma, Eric; Estrin, Michael; Viswanathan, Karthik; Stebbins, Nathan W.; Quinlan, Devin S.; Sasisekharan, Ram; Runstadler, Jonathan

    2016-01-01

    An influenza H3N8 virus, carrying mammalian adaptation mutations, was isolated from New England harbor seals in 2011. We sought to assess the risk of its human transmissibility using two complementary approaches. First, we tested the binding of recombinant hemagglutinin (HA) proteins of seal H3N8 and human-adapted H3N2 viruses to respiratory tissues of humans and ferrets. For human tissues, we observed strong tendency of the seal H3 to bind to lung alveoli, which was in direct contrast to the human-adapted H3 that bound mainly to the trachea. This staining pattern was also consistent in ferrets, the primary animal model for human influenza pathogenesis. Second, we compared the binding of the recombinant HAs to a library of 610 glycans. In contrast to the human H3, which bound almost exclusively to α-2,6 sialylated glycans, the seal H3 bound preferentially to α-2,3 sialylated glycans. Additionally, the seal H3N8 virus replicated in human lung carcinoma cells. Our data suggest that the seal H3N8 virus has retained its avian-like receptor binding specificity, but could potentially establish infection in human lungs. PMID:26888262

  6. Influenza virus: transmission between species and relevance to emergence of the next human pandemic.

    PubMed

    Webster, R G

    1997-01-01

    Although influenza viruses are not spread from human to human through the conventional food chain, this is not necessarily the case for the transmission of the precursors of the human pandemic influenza viruses. Aquatic birds of the world are the reservoirs for all influenza A viruses; the virus is spread by fecal-oral transmission in untreated water. Influenza A viruses are frequently transmitted to domestic poultry and two of the 15 subtypes H5 and H7 can become highly pathogenic and have the capacity to decimate commercial poultry flocks. Less frequently, avian influenza viruses are transmitted between species-to pigs, horses and sea mammals. This transmission involves mutational, reassortant or recombinational events and can occur through fecal contamination of unprocessed avian protein or through the water. The transmission of avian influenza viruses or virus genes to humans is postulated to occur through pigs that act as the intermediate host. This involves either multiple mutational or reassortant events and is believed to occur by airborne transmission. Once avian influenza viruses are established in mammals, they are transmitted from animal to animal by the respiratory airborne route. The transmission of avian influenza virus from their reservoir in wild aquatic birds to domestic poultry and to mammalian species including humans can be prevented by treatment of the water supply and of avian protein sources with disinfectants or by heating. Agricultural authorities have recommended the separation of wild aquatic and domestic poultry and of pig and poultry farming. It is theoretically possible to reduce the possibility of the next pandemic of influenza in humans by changes in agricultural practices so that ducks are separated from pigs and people.

  7. Evaluation of cytokine gene expression after avian influenza virus infection in avian cell lines and primary cell cultures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The innate immune responses elicited by avian influenza virus (AIV) infection has been studied by measuring cytokine gene expression by relative real time PCR (rRT-PCR) in vitro, using both cell lines and primary cell cultures. Continuous cell lines offer advantages over the use of primary cell cult...

  8. Transmission and reassortment of avian influenza viruses at the Asian-North American interface

    USGS Publications Warehouse

    Ramey, Andrew M.; Pearce, John M.; Ely, Craig R.; Guy, Lisa M. Sheffield; Irons, David B.; Derksen, Dirk V.; Ip, Hon S.

    2010-01-01

    Twenty avian influenza viruses were isolated from seven wild migratory bird species sampled at St. Lawrence Island, Alaska. We tested predictions based on previous phylogenetic analyses of avian influenza viruses that support spatially dependent trans-hemispheric gene flow and frequent interspecies transmission at a location situated at the Asian–North American interface. Through the application of phylogenetic and genotypic approaches, our data support functional dilution by distance of trans-hemispheric reassortants and interspecific virus transmission. Our study confirms infection of divergent avian taxa with nearly identical avian influenza strains in the wild. Findings also suggest that H16N3 viruses may contain gene segments with unique phylogenetic positions and that further investigation of how host specificity may impact transmission of H13 and H16 viruses is warranted.

  9. Review: molecular evolution and the feasibility of an avian influenza virus becoming a pandemic strain--a conceptual shift.

    PubMed

    Shoham, Dany

    2006-10-01

    During recent years, a conceptual shift took place with respect to the genetic dynamics of influenza A viruses. In difference of the widely accepted approach that avian viral strains have the capacity to infect man only after undergoing genetic reassortment within pigs, it is now contended that direct transfection of man by intact avian-harbored viral genotypes is an actual, recurrent move, which may bring bout the generation of a new pandemic strain. This cardinal conceptual shift has been propelled by the appearance in 1997 of the zoonotic avian influenza H5N1 virus--a virulent, not yet contagious strain for humans--and ostensibly followed a genuine, unprecedented path within the evolutionary paradigm of Influenza A virus. This paper suggests that direct avian-human genetic interface is a pristine fundamental within the natural history of this protean pathogen, points at earlier as well as corroborative findings leading to such postulation, and regards the course of the H5N1 virus (and alike), as a readily detectable and traceable one, presently, rather then a novel development It further examines the general feasibility of various components of that interface at large, such that give rise--whether gradually or abruptly--to pandemic genotypes, in terms of infectivity, pathogenicity and contagiousness. Within that context, the anticipated involvement of certain human-adapted antigenic subtypes is referred to, extrapolatively. Connectedly, the significance of natural ice as plausible regenerator of influenza A viruses, and its possible contribution to the emergence and reemergence of pandemic strains are accentuated. PMID:16972025

  10. Highly Pathogenic Avian Influenza Virus Infection of Mallards with Homo- and Heterosubtypic Immunity Induced by Low Pathogenic Avian Influenza Viruses

    PubMed Central

    Fereidouni, Sasan R.; Starick, Elke; Beer, Martin; Wilking, Hendrik; Kalthoff, Donata; Grund, Christian; Häuslaigner, Rafaela; Breithaupt, Angele; Lange, Elke; Harder, Timm C.

    2009-01-01

    The potential role of wild birds as carriers of highly pathogenic avian influenza virus (HPAIV) subtype H5N1 is still a matter of debate. Consecutive or simultaneous infections with different subtypes of influenza viruses of low pathogenicity (LPAIV) are very common in wild duck populations. To better understand the epidemiology and pathogenesis of HPAIV H5N1 infections in natural ecosystems, we investigated the influence of prior infection of mallards with homo- (H5N2) and heterosubtypic (H4N6) LPAIV on exposure to HPAIV H5N1. In mallards with homosubtypic immunity induced by LPAIV infection, clinical disease was absent and shedding of HPAIV from respiratory and intestinal tracts was grossly reduced compared to the heterosubtypic and control groups (mean GEC/100 µl at 3 dpi: 3.0×102 vs. 2.3×104 vs. 8.7×104; p<0.05). Heterosubtypic immunity induced by an H4N6 infection mediated a similar but less pronounced effect. We conclude that the epidemiology of HPAIV H5N1 in mallards and probably other aquatic wild bird species is massively influenced by interfering immunity induced by prior homo- and heterosubtypic LPAIV infections. PMID:19693268

  11. Landscape attributes driving avian influenza virus circulation in the Lake Alaotra region of Madagascar.

    PubMed

    Guerrini, Laure; Paul, Mathilde C; Leger, Lucas; Andriamanivo, Harentsoaniaina R; Maminiaina, Olivier F; Jourdan, Marion; Molia, Sophie; Rakotondravao, René; Chevalier, Véronique

    2014-05-01

    While the spatial pattern of the highly pathogenic avian influenza H5N1 virus has been studied throughout Southeast Asia, little is known on the spatial risk factors for avian influenza in Africa. In the present paper, we combined serological data from poultry and remotely sensed environmental factors in the Lake Alaotra region of Madagascar to explore for any association between avian influenza and landscape variables. Serological data from cross-sectional surveys carried out on poultry in 2008 and 2009 were examined together with a Landsat 7 satellite image analysed using supervised classification. The dominant landscape features in a 1-km buffer around farmhouses and distance to the closest water body were extracted. A total of 1,038 individual bird blood samples emanating from 241 flocks were analysed, and the association between avian influenza seroprevalence and these landcape variables was quantified using logistic regression models. No evidence of the presence of H5 or H7 avian influenza subtypes was found, suggesting that only low pathogenic avian influenza (LPAI) circulated. Three predominant land cover classes were identified around the poultry farms: grassland savannah, rice paddy fields and wetlands. A significant negative relationship was found between LPAI seroprevalence and distance to the closest body of water. We also found that LPAI seroprevalence was higher in farms characterised by predominant wetlands or rice landscapes than in those surrounded by dry savannah. Results from this study suggest that if highly pathogenic avian influenza H5N1 virus were introduced in Madagascar, the environmental conditions that prevail in Lake Alaotra region may allow the virus to spread and persist. PMID:24893021

  12. 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

    2015-01-01

    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

  13. 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

  14. Rice production systems and avian influenza: Interactions between mixed-farming systems, poultry and wild birds

    USGS Publications Warehouse

    Muzaffar, S.B.; Takekawa, J.Y.; Prosser, D.J.; Newman, S.H.; Xiao, X.

    2010-01-01

    Wild waterfowl are the reservoir for avian influenza viruses (AIVs), a family of RNA viruses that may cause mild sickness in waterbirds. Emergence of H5N1, a highly pathogenic avian influenza (HPAI) strain, causing severe disease and mortality in wild birds, poultry and humans, had raised concerns about the role of wild birds in possible transmission of the disease. In this review, the link between rice production systems, poultry production systems, and wild bird ecology is examined to assess the extent to which these interactions could contribute towards the persistence and evolution of HPAI H5N1. The rice (Oryza sativa) and poultry production systems in Asia described, and then migration and movements of wild birds discussed. Mixed farming systems in Asia and wild bird movement and migration patterns create opportunities for the persistence of low pathogenic AIVs in these systems. Nonetheless, there is no evidence of long-term persistence of HPAI viruses (including the H5N1 subtype) in the wild. There are still significant gaps in the understanding of how AIVs circulate in rice systems. A better understanding of persistence of AIVs in rice farms, particularly of poultry origins, is essential in limiting exchange of AIVs between mixed-farming systems, poultry and wild birds.

  15. Genetic analysis of H9N2 avian influenza viruses isolated from India.

    PubMed

    Tosh, C; Nagarajan, S; Behera, P; Rajukumar, K; Purohit, K; Kamal, R P; Murugkar, H V; Gounalan, S; Pattnaik, B; Vanamayya, P R; Pradhan, H K; Dubey, S C

    2008-01-01

    H9N2 avian influenza viruses are endemic in domestic poultry in Asia and are grouped into three major sublineages represented by their prototype strains A/Duck/Hong Kong/Y280/97 (Y280-like), A/Quail/Hong Kong/G1/97 (G1-like) and A/Chicken/Korea/38349-p96323/96 (Korean-like). To understand the genetic relationship of Indian viruses, we determined the partial nucleotide sequence of five H9N2 avian influenza viruses isolated from chicken in India during 2003-2004 and compared them with H9N2 sequences available in GenBank. Deduced amino acid sequence analysis revealed that four isolates shared an R-S-S-R/G motif at the cleavage site of HA, representing low pathogenicity in chickens, while one virus harbors an R-S-N-R/G motif at the same position. All the viruses maintained the human-like motif 226Lysine (H3 numbering) at the HA receptor binding site. Phylogenetic analysis showed that 50% of the genes (HA, NA, NP and M) were similar to G1-like viruses, whereas the remaining genes of the Indian isolates formed a separate, not yet defined, sublineage in the Eurasian lineage. Our finding provides evidence of a novel reassortant H9N2 genotype of G1-like viruses circulating in India.

  16. 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.

  17. Serological Survey for Avian Influenza in Turkeys in Three States of Southwest Nigeria.

    PubMed

    Oluwayelu, Daniel Oladimeji; Aiki-Raji, Comfort Oluladun; Adigun, Oladunni Taiwo; Olofintuyi, Opeyemi Kazeem; Adebiyi, Adebowale Idris

    2015-01-01

    Since the first outbreak of avian influenza (AI) in Nigeria in 2006, there has been continuous monitoring of the disease in chickens with little attention given to turkeys. As part of on-going surveillance for AI in southwest Nigeria, we used a competitive ELISA to detect anti-AI virus antibodies in 520 turkey sera obtained from poultry farms in Oyo, Osun, and Ondo states while haemagglutination inhibiting antibodies against low pathogenic AI viruses (LPAIVs) were detected using H3N8 and H5N2 subtype-specific antigens. The overall seroprevalence obtained by ELISA was 4.4% (23/520). Of the 23 ELISA-positive samples, 18 were positive for anti-AIV H3N8 antibodies only and four were positive for both anti-AIV H3N8 and H5N2 antibodies indicating a mixed infection, while five were negative for antibodies to either of the two AIV subtypes. Considering that turkeys have been implicated as a mixing vessel for generating influenza virus reassortants of human and avian origin, the detection of antibodies to LPAIV H3N8 and H5N2 in these turkeys is of public health concern. We advocate further studies to determine the potential role of turkeys in the zoonotic transmission of AIVs in Nigeria. Additionally, the practice of rearing turkeys with chickens should be discouraged. PMID:26664747

  18. Serological Survey for Avian Influenza in Turkeys in Three States of Southwest Nigeria

    PubMed Central

    Oluwayelu, Daniel Oladimeji; Aiki-Raji, Comfort Oluladun; Adigun, Oladunni Taiwo; Olofintuyi, Opeyemi Kazeem; Adebiyi, Adebowale Idris

    2015-01-01

    Since the first outbreak of avian influenza (AI) in Nigeria in 2006, there has been continuous monitoring of the disease in chickens with little attention given to turkeys. As part of on-going surveillance for AI in southwest Nigeria, we used a competitive ELISA to detect anti-AI virus antibodies in 520 turkey sera obtained from poultry farms in Oyo, Osun, and Ondo states while haemagglutination inhibiting antibodies against low pathogenic AI viruses (LPAIVs) were detected using H3N8 and H5N2 subtype-specific antigens. The overall seroprevalence obtained by ELISA was 4.4% (23/520). Of the 23 ELISA-positive samples, 18 were positive for anti-AIV H3N8 antibodies only and four were positive for both anti-AIV H3N8 and H5N2 antibodies indicating a mixed infection, while five were negative for antibodies to either of the two AIV subtypes. Considering that turkeys have been implicated as a mixing vessel for generating influenza virus reassortants of human and avian origin, the detection of antibodies to LPAIV H3N8 and H5N2 in these turkeys is of public health concern. We advocate further studies to determine the potential role of turkeys in the zoonotic transmission of AIVs in Nigeria. Additionally, the practice of rearing turkeys with chickens should be discouraged. PMID:26664747

  19. H5N1 highly pathogenic avian influenza in Indonesia: retrospective considerations.

    PubMed

    Daniels, Peter; Wiyono, Agus; Sawitri, Elly; Poermadjaja, Bagoes; Sims, L D

    2013-01-01

    Indonesia is one of the five countries where highly pathogenic avian influenza viruses of the H5N1 subtype (H5N1 HPAI) remain endemic in poultry. Importantly, it is one of the countries where the virus causes human infections. WHO data indicate that as of 2 May 2012, 189 human cases of Influenza A (H5N1) had been reported in Indonesia, with 157 human deaths. These human cases included a small number in which limited human-to-human transmission could have occurred. Hence, there remains a critical need in Indonesia for a more effective One Health approach to the control and prevention of this disease in people and in poultry. This chapter explores a number of aspects of the evolution of this disease in Indonesia, the virus that causes it and the control and preventive measures introduced, focusing on the successes and shortcomings of veterinary and One Health approaches. Indonesia provides many examples of situations where this latter approach has been successful, and others where further work is needed to maximize the benefits from coordinated responses to this disease leading to effective management of the risk to human health.

  20. A synchronized global sweep of the internal genes of modern avian influenza virus.

    PubMed

    Worobey, Michael; Han, Guan-Zhu; Rambaut, Andrew

    2014-04-10

    Zoonotic infectious diseases such as influenza continue to pose a grave threat to human health. However, the factors that mediate the emergence of RNA viruses such as influenza A virus (IAV) are still incompletely understood. Phylogenetic inference is crucial to reconstructing the origins and tracing the flow of IAV within and between hosts. Here we show that explicitly allowing IAV host lineages to have independent rates of molecular evolution is necessary for reliable phylogenetic inference of IAV and that methods that do not do so, including 'relaxed' molecular clock models, can be positively misleading. A phylogenomic analysis using a host-specific local clock model recovers extremely consistent evolutionary histories across all genomic segments and demonstrates that the equine H7N7 lineage is a sister clade to strains from birds--as well as those from humans, swine and the equine H3N8 lineage--sharing an ancestor with them in the mid to late 1800s. Moreover, major western and eastern hemisphere avian influenza lineages inferred for each gene coalesce in the late 1800s. On the basis of these phylogenies and the synchrony of these key nodes, we infer that the internal genes of avian influenza virus (AIV) underwent a global selective sweep beginning in the late 1800s, a process that continued throughout the twentieth century and up to the present. The resulting western hemispheric AIV lineage subsequently contributed most of the genomic segments to the 1918 pandemic virus and, independently, the 1963 equine H3N8 panzootic lineage. This approach provides a clear resolution of evolutionary patterns and processes in IAV, including the flow of viral genes and genomes within and between host lineages.

  1. 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 ...

  2. 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)...

  3. Cross reactive antibody and cytotoxic T lymphocytes from avian influenza H9N2 infected chickens against homologous and heterologous avian influenza isolates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immunity against avian influenza (AI) is largely based on the induction of neutralizing antibodies produced against the hemagglutinin, although cytotoxic T lymphocytes (CTL’s) have been reported as critical for clearance of virus from infected cells. Antibody production against a particular virus ...

  4. Protection against H7N3 high pathogenicity avian influenza in chickens immunized with a recombinant fowlpox and an inactivated avian influenza vaccines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beginning on June 2012, an H7N3 highly pathogenic avian influenza (HPAI) epizootic was reported in the State of Jalisco (Mexico), with some 22.4 million chickens that died, were slaughtered on affected farms or were preemptively culled on neighboring farms. In the current study, layer chickens were ...

  5. Reduction of high pathogenicity avian influenza virus in eggs from chickens once or twice vaccinated with an oil-emulsified inactivated H5 avian influenza vaccine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The negative impact of high pathogenicity avian influenza virus (HPAIV) infection on egg production and deposition of virus in eggs, as well as any protective effect of vaccination, is unknown. Individually housed non-vaccinated, sham-vaccinated and inactivated H5N9 vaccinated once or twice adult Wh...

  6. Protection of poultry against the 2012 Mexican H7N3 highly pathogenic avian influenza virus with inactivated H7 avian influenza vaccines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In June of 2012, an outbreak of highly pathogenic avian influenza (HPAI) H7N3 was reported poultry in Jalisco, Mexico. Since that time the virus has spread to the surrounding States of Guanajuato and Aguascalientes and new outbreaks continue to be reported. To date more than 25 million birds have di...

  7. 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...

  8. Epidemiology, Evolution, and Recent Outbreaks of Avian Influenza Virus in China.

    PubMed

    Su, Shuo; Bi, Yuhai; Wong, Gary; Gray, Gregory C; Gao, George F; Li, Shoujun

    2015-09-01

    Novel reassortants of H7N9, H10N8, and H5N6 avian influenza viruses (AIVs) are currently circulating in China's poultry flocks, occasionally infecting humans and other mammals. Combined with the sometimes enzootic H5N1 and H9N2 strains, this cauldron of genetically diverse AIVs pose significant risks to public health. Here, we review the epidemiology, evolution, and recent outbreaks of AIVs in China, discuss reasons behind the recent increase in the emergence of novel AIVs, and identify warning signs which may point to the emergence of a potentially virulent and highly transmissible AIV to humans. This review will be useful to authorities who consider options for the detection and control of AIV transmission in animals and humans, with the goal of preventing future epidemics and pandemics.

  9. Epidemiology, Evolution, and Recent Outbreaks of Avian Influenza Virus in China

    PubMed Central

    Su, Shuo; Wong, Gary; Gray, Gregory C.; Gao, George F.

    2015-01-01

    Novel reassortants of H7N9, H10N8, and H5N6 avian influenza viruses (AIVs) are currently circulating in China's poultry flocks, occasionally infecting humans and other mammals. Combined with the sometimes enzootic H5N1 and H9N2 strains, this cauldron of genetically diverse AIVs pose significant risks to public health. Here, we review the epidemiology, evolution, and recent outbreaks of AIVs in China, discuss reasons behind the recent increase in the emergence of novel AIVs, and identify warning signs which may point to the emergence of a potentially virulent and highly transmissible AIV to humans. This review will be useful to authorities who consider options for the detection and control of AIV transmission in animals and humans, with the goal of preventing future epidemics and pandemics. PMID:26063419

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

    PubMed Central

    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. PMID:26274828

  11. Susceptibility and Status of Avian Influenza in Ostriches.

    PubMed

    Abolnik, Celia; Olivier, Adriaan; Reynolds, Chevonne; Henry, Dominic; Cumming, Graeme; Rauff, Dionne; Romito, Marco; Petty, Deryn; Falch, Claudia

    2016-05-01

    The extensive nature of ostrich farming production systems bears the continual risk of point introductions of avian influenza virus (AIV) from wild birds, but immune status, management, population density, and other causes of stress in ostriches are the ultimate determinants of the severity of the disease in this species. From January 2012 to December 2014, more than 70 incidents of AIV in ostriches were reported in South Africa. These included H5N2 and H7N1 low pathogenicity avian influenza (LPAI) in 2012, H7N7 LPAI in 2013, and H5N2 LPAI in 2014. To resolve the molecular epidemiology in South Africa, the entire South African viral repository from ostriches and wild birds from 1991 to 2013 (n = 42) was resequenced by next-generation sequencing technology to obtain complete genomes for comparison. The phylogenetic results were supplemented with serological data for ostriches from 2012 to 2014, and AIV-detection data from surveillance of 17 762 wild birds sampled over the same period. Phylogenetic evidence pointed to wild birds, e.g., African sacred ibis (Threskiornis aethiopicus), in the dissemination of H7N1 LPAI to ostriches in the Eastern and Western Cape provinces during 2012, in separate incidents that could not be epidemiologically linked. In contrast, the H7N7 LPAI outbreaks in 2013 that were restricted to the Western Cape Province appear to have originated from a single-point introduction from wild birds. Two H5N2 viruses detected in ostriches in 2012 were determined to be LPAI strains that were new introductions, epidemiologically unrelated to the 2011 highly pathogenic avian influenza (HPAI) outbreaks. Seventeen of 27 (63%) ostrich viruses contained the polymerase basic 2 (PB2) E627K marker, and 2 of the ostrich isolates that lacked E627K contained the compensatory Q591K mutation, whereas a third virus had a D701N mutation. Ostriches maintain a low upper- to midtracheal temperature as part of their adaptive physiology for desert survival, which may

  12. Susceptibility and Status of Avian Influenza in Ostriches.

    PubMed

    Abolnik, Celia; Olivier, Adriaan; Reynolds, Chevonne; Henry, Dominic; Cumming, Graeme; Rauff, Dionne; Romito, Marco; Petty, Deryn; Falch, Claudia

    2016-05-01

    The extensive nature of ostrich farming production systems bears the continual risk of point introductions of avian influenza virus (AIV) from wild birds, but immune status, management, population density, and other causes of stress in ostriches are the ultimate determinants of the severity of the disease in this species. From January 2012 to December 2014, more than 70 incidents of AIV in ostriches were reported in South Africa. These included H5N2 and H7N1 low pathogenicity avian influenza (LPAI) in 2012, H7N7 LPAI in 2013, and H5N2 LPAI in 2014. To resolve the molecular epidemiology in South Africa, the entire South African viral repository from ostriches and wild birds from 1991 to 2013 (n = 42) was resequenced by next-generation sequencing technology to obtain complete genomes for comparison. The phylogenetic results were supplemented with serological data for ostriches from 2012 to 2014, and AIV-detection data from surveillance of 17 762 wild birds sampled over the same period. Phylogenetic evidence pointed to wild birds, e.g., African sacred ibis (Threskiornis aethiopicus), in the dissemination of H7N1 LPAI to ostriches in the Eastern and Western Cape provinces during 2012, in separate incidents that could not be epidemiologically linked. In contrast, the H7N7 LPAI outbreaks in 2013 that were restricted to the Western Cape Province appear to have originated from a single-point introduction from wild birds. Two H5N2 viruses detected in ostriches in 2012 were determined to be LPAI strains that were new introductions, epidemiologically unrelated to the 2011 highly pathogenic avian influenza (HPAI) outbreaks. Seventeen of 27 (63%) ostrich viruses contained the polymerase basic 2 (PB2) E627K marker, and 2 of the ostrich isolates that lacked E627K contained the compensatory Q591K mutation, whereas a third virus had a D701N mutation. Ostriches maintain a low upper- to midtracheal temperature as part of their adaptive physiology for desert survival, which may

  13. Genomic Signatures for Avian H7N9 Viruses Adapting to Humans.

    PubMed

    Chen, Guang-Wu; Kuo, Shu-Ming; Yang, Shu-Li; Gong, Yu-Nong; Hsiao, Mei-Ren; Liu, Yi-Chun; Shih, Shin-Ru; Tsao, Kuo-Chien

    2016-01-01

    An avian influenza A H7N9 virus emerged in March 2013 and caused a remarkable number of human fatalities. Genome variability in these viruses may provide insights into host adaptability. We scanned over 140 genomes of the H7N9 viruses isolated from humans and identified 104 positions that exhibited seven or more amino acid substitutions. Approximately half of these substitutions were identified in the influenza ribonucleoprotein (RNP) complex. Although PB2 627K of the avian virus promotes replication in humans, 45 of the 147 investigated PB2 sequences retained the E signature at this position, which is an avian characteristic. We discovered 10 PB2 substitutions that covaried with K627E. An RNP activity assay showed that Q591K, D701N, and M535L restored the polymerase activity in human cells when 627K transformed to an avian-like E. Genomic analysis of the human-isolated avian influenza virus is crucial in assessing genome variability, because relationships between position-specific variations can be observed and explored. In this study, we observed alternative positions that can potentially compensate for PB2 627K, a well-known marker for cross-species infection. An RNP assay suggested Q591K, D701N, and M535L as potential markers for an H7N9 virus capable of infecting humans.

  14. The East Jakarta Project: surveillance for highly pathogenic avian influenza A(H5N1) and seasonal influenza viruses in patients seeking care for respiratory disease, Jakarta, Indonesia, October 2011-September 2012.

    PubMed

    Storms, A D; Kusriastuti, R; Misriyah, S; Praptiningsih, C Y; Amalya, M; Lafond, K E; Samaan, G; Triada, R; Iuliano, A D; Ester, M; Sidjabat, R; Chittenden, K; Vogel, R; Widdowson, M A; Mahoney, F; Uyeki, T M

    2015-12-01

    Indonesia has reported the most human infections with highly pathogenic avian influenza (HPAI) A(H5N1) virus worldwide. We implemented enhanced surveillance in four outpatient clinics and six hospitals for HPAI H5N1 and seasonal influenza viruses in East Jakarta district to assess the public health impact of influenza in Indonesia. Epidemiological and clinical data were collected from outpatients with influenza-like illness (ILI) and hospitalized patients with severe acute respiratory infection (SARI); respiratory specimens were obtained for influenza testing by real-time reverse transcription-polymerase chain reaction. During October 2011-September 2012, 1131/3278 specimens from ILI cases (34·5%) and 276/1787 specimens from SARI cases (15·4%) tested positive for seasonal influenza viruses. The prevalence of influenza virus infections was highest during December-May and the proportion testing positive was 76% for ILI and 36% for SARI during their respective weeks of peak activity. No HPAI H5N1 virus infections were identified, including hundreds of ILI and SARI patients with recent poultry exposures, whereas seasonal influenza was an important contributor to acute respiratory disease in East Jakarta. Overall, 668 (47%) of influenza viruses were influenza B, 384 (27%) were A(H1N1)pdm09, and 359 (25%) were H3. While additional data over multiple years are needed, our findings suggest that seasonal influenza prevention efforts, including influenza vaccination, should target the months preceding the rainy season.

  15. Experimental infection of mallard ducks with different subtype H5 and H7 highly pathogenic avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic avian influenza viruses (HPAIV’s) remain a threat to poultry worldwide. Avian influenza viruses, including HPAIV, are usually non-pathogenic for ducks and other wild aquatic birds, with the exception of some Asian lineage H5N1 HPAIVs which can cause severe disease in ducks. With ...

  16. Avian influenza in North and South America, 2002-2005.

    PubMed

    Senne, Dennis A

    2007-03-01

    Between 2002 and 2005, three outbreaks of highly pathogenic avian influenza (HPAI) occurred in the Americas: one outbreak in Chile (H7N3) in 2002, one outbreak in the United States (H5N2) in 2004, and one outbreak in Canada (H7N3) in 2004. The outbreak in Chile was limited to a large broiler breeder operation and a nearby turkey flock and represented the first outbreak of HPAI in that country. The outbreak of HPAI in the United States occurred in Texas and was limited to one premise where chickens were raised for sale in nearby live-bird markets. The outbreak in Canada was the largest of the three HPAI outbreaks, involving 42 premises and approximately 17 million birds in the Fraser Valley, British Columbia. In each of the HPAI outbreaks, the disease was successfully eradicated by depopulation of infected farms. All other reports of infections in poultry and isolations from wild bird species pertained to low pathogenicity avian influenza (LPAI) viruses. Animal Health Officials in Canada reported subtypes H3, H5, and H6 in domestic poultry, and H3, H5, H11, and H13 from imported and/or wild bird species. An LPAI H5N2 virus continues to circulate in Mexico and the Central American countries of Guatemala and El Salvador. Each country reported isolations of H5N2 virus from poultry and the large-scale use of inactivated and recombinant H5 vaccines in their AI control programs. In Colombia, AI was reported for the first time when antibodies to H9N2 were detected in chickens by routine surveillance. Intensive surveillance activities in the United States detected AI virus or specific antibodies to 13 of the 16 hemagglutinin (H1-H13) and all nine neuraminidase subtypes in live-bird markets, small holder farms, and in commercial poultry from 29 states. The largest outbreak of LPAI in the United States occurred in 2002, when 197 farms were depopulated (4.7 million birds) to control an outbreak in Virginia and surrounding states. The outbreak was caused by an LPAI H7N2 virus

  17. Impact of vaccines and vaccination on global control of avian influenza.

    PubMed

    Swayne, David E

    2012-12-01

    There are 30 recorded epizootics of H5 or H7 high pathogenicity avian influenza (HPAI) from 1959 to early 2012. The largest of these epizootics, affecting more birds and countries than the other 29 epizootics combined, has been the H5N1 HPAI, which began in Guangdong China in 1996, and has killed or resulted in culling of over 250 million poultry and/or wild birds in 63 countries. Most countries have used stamping-out programs in poultry to eradicate H5N1 HPAI. However, 15 affected countries have utilized vaccination as a part of the control strategy. Greater than 113 billion doses were used from 2002 to 2010. Five countries have utilized nationwide routine vaccination programs, which account for 99% of vaccine used: 1) China (90.9%), 2) Egypt (4.6%), 3) Indonesia (2.3%), 4) Vietnam (1.4%), and 5) Hong Kong Special Administrative Region (< 0.01%). Mongolia, Kazakhstan, France, The Netherlands, Cote d'Ivoire, Sudan, North Korea, Israel, Russia, and Pakistan used < 1% of the avian influenza (AI) vaccine, and the AI vaccine was targeted to either preventive or emergency vaccination programs. Inactivated AI vaccines have accounted for 95.5% of vaccine used, and live recombinant virus vaccines have accounted for 4.5% of vaccine used. The latter are primarily recombinant Newcastle disease vectored vaccine with H5 influenza gene insert. China, Indonesia, Egypt, and Vietnam implemented vaccination after H5N1 HPAI became enzootic in domestic poultry. Bangladesh and eastern India have enzootic H5N1 HPAI and have not used vaccination in their control programs. Clinical disease and mortality have been prevented in chickens, human cases have been reduced, and rural livelihoods and food security have been maintained by using vaccines during HPAI outbreaks. However, field outbreaks have occurred in vaccinating countries, primarily because of inadequate coverage in the target species, but vaccine failures have occurred following antigenic drift in field viruses within China, Egypt

  18. Global Avian Influenza Surveillance in Wild Birds: A Strategy to Capture Viral Diversity

    PubMed Central

    Machalaba, Catherine C.; Elwood, Sarah E.; Forcella, Simona; Smith, Kristine M.; Hamilton, Keith; Jebara, Karim B.; Swayne, David E.; Webby, Richard J.; Mumford, Elizabeth; Mazet, Jonna A.K.; Gaidet, Nicolas; Daszak, Peter

    2015-01-01

    Wild birds play a major role in the evolution, maintenance, and spread of avian influenza viruses. However, surveillance for these viruses in wild birds is sporadic, geographically biased, and often limited to the last outbreak virus. To identify opportunities to optimize wild bird surveillance for understanding viral diversity, we reviewed responses to a World Organisation for Animal Health–administered survey, government reports to this organization, articles on Web of Knowledge, and the Influenza Research Database. At least 119 countries conducted avian influenza virus surveillance in wild birds during 2008–2013, but coordination and standardization was lacking among surveillance efforts, and most focused on limited subsets of influenza viruses. Given high financial and public health burdens of recent avian influenza outbreaks, we call for sustained, cost-effective investments in locations with high avian influenza diversity in wild birds and efforts to promote standardized sampling, testing, and reporting methods, including full-genome sequencing and sharing of isolates with the scientific community. PMID:25811221

  19. Global avian influenza surveillance in wild birds: a strategy to capture viral diversity.

    PubMed

    Machalaba, Catherine C; Elwood, Sarah E; Forcella, Simona; Smith, Kristine M; Hamilton, Keith; Jebara, Karim B; Swayne, David E; Webby, Richard J; Mumford, Elizabeth; Mazet, Jonna A K; Gaidet, Nicolas; Daszak, Peter; Karesh, William B

    2015-04-01

    Wild birds play a major role in the evolution, maintenance, and spread of avian influenza viruses. However, surveillance for these viruses in wild birds is sporadic, geographically biased, and often limited to the last outbreak virus. To identify opportunities to optimize wild bird surveillance for understanding viral diversity, we reviewed responses to a World Organisation for Animal Health-administered survey, government reports to this organization, articles on Web of Knowledge, and the Influenza Research Database. At least 119 countries conducted avian influenza virus surveillance in wild birds during 2008-2013, but coordination and standardization was lacking among surveillance efforts, and most focused on limited subsets of influenza viruses. Given high financial and public health burdens of recent avian influenza outbreaks, we call for sustained, cost-effective investments in locations with high avian influenza diversity in wild birds and efforts to promote standardized sampling, testing, and reporting methods, including full-genome sequencing and sharing of isolates with the scientific community. PMID:25811221

  20. Pathogenesis of novel reassortant avian influenza virus A (H5N8) Isolates in the ferret.

    PubMed

    Kim, Heui Man; Kim, Chi-Kyeong; Lee, Nam-Joo; Chu, Hyuk; Kang, Chun; Kim, Kisoon; Lee, Joo-Yeon

    2015-07-01

    Outbreaks of avian influenza virus H5N8 first occurred in 2014, and spread to poultry farms in Korea. Although there was no report of human infection by this subtype, it has the potential to threaten human public health. Therefore, we evaluated the pathogenesis of H5N8 viruses in ferrets. Two representative Korean H5N8 strains did not induce mortality and significant respiratory signs after an intranasal challenge in ferrets. However, ferrets intratracheally infected with A/broiler duck/Korea/Buan2/2014 virus showed dose-dependent mortality. Although the Korean H5N8 strains were classified as the HPAI virus, possessing multiple basic amino acids in the cleavage site of the hemagglutinin sequence, they did not produce pathogenesis in ferrets challenged intranasally, similar to the natural infection route. These results could be useful for public health by providing the pathogenic characterization of H5N8 viruses. PMID:25776760

  1. Impact of route of exposure and challenge dose on the pathogenesis of H7N9 low pathogenicity avian influenza virus in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    H7N9 influenza A first caused human infections, often with severe disease, in early 2013 in China. Virus genetics, histories of patient exposures to poultry, and previous experimental studies all point to the source of the virus being a domestic avian species, such as chickens. In order to better ...

  2. 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...

  3. Pathogenicity of swine influenza viruses possessing an avian or swine-origin PB2 polymerase gene evaluated in mouse and pig models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A viruses isolated from birds normally contain a PB2 polymerase gene with the avian-signature glutamic acid (E) at position 627, while those isolated from humans contain the mammalian-signature lysine (K) at this position. This residue has been shown to be a determinant of host range and c...

  4. [Screening efficient siRNAs in vitro as the candidate genes for chicken anti-avian influenza virus H5N1 breeding].

    PubMed

    Zhang, P; Wang, J G; Wan, J G; Liu, W Q

    2010-01-01

    The frequent disease outbreaks caused by avian influenza virus not only affect the poultry industry but also pose a threat to human safety. To address the problem, RNA interference (RNAi) has recently been widely used as a potential antiviral approach. Transgenesis in combination with RNAi to specifically inhibit avian enza virus gene expression has been proposed to make chickens resistant to the infection. For the transgenic breeding, screening in vitro efficient siRNAs as the candidate genes is one of the most important tasks. Here, we combined an online search tool and a series of bioinformatics programs with a set of rules for designing siRNAs targeted towards different mRNA regions of H5N1 avian influenza virus. Five rational siRNAs were chosen by this method, five U6 promoter-driven shRNA expression plasmids containing the siRNA genes were constructed and used for producing stably transfected MDCK cells. The data obtained by virus titration, IFA, PI-stained flow cytometry, real-time quantitative RT-PCR, and DAS-ELISA analyses showed that all five stably transfected cell lines we re resistant to virusreplication when exposed to 100 CCID50 of avian influenza virus H5N1. Finally, most effective plasmids (pSi-604i and pSi-1597i) as the candidates for making the transgenic chickens were chosen. These findings provide baseline information on use of RNAi technique for breeding transgenic chickens resistant to avian influenza virus.

  5. Little evidence of avian or equine influenza virus infection among a cohort of Mongolian adults with animal exposures, 2010-2011.

    PubMed

    Khurelbaatar, Nyamdavaa; Krueger, Whitney S; Heil, Gary L; Darmaa, Badarchiin; Ulziimaa, Daramragchaa; Tserennorov, Damdindorj; Baterdene, Ariungerel; Anderson, Benjamin D; Gray, Gregory C

    2014-01-01

    Avian (AIV) and equine influenza virus (EIV) have been repeatedly shown to circulate among Mongolia's migrating birds or domestic horses. In 2009, 439 Mongolian adults, many with occupational exposure to animals, were enrolled in a prospective cohort study of zoonotic influenza transmission. Sera were drawn upon enrollment and again at 12 and 24 months. Participants were contacted monthly for 24 months and queried regarding episodes of acute influenza-like illnesses (ILI). Cohort members confirmed to have acute influenza A infections, permitted respiratory swab collections which were studied with rRT-PCR for influenza A. Serologic assays were performed against equine, avian, and human influenza viruses. Over the 2 yrs of follow-up, 100 ILI investigations in the cohort were conducted. Thirty-six ILI cases (36%) were identified as influenza A infections by rRT-PCR; none yielded evidence for AIV or EIV. Serological examination of 12 mo and 24 mo annual sera revealed 37 participants had detectable antibody titers (≥1∶10) against studied viruses during the course of study follow-up: 21 against A/Equine/Mongolia/01/2008(H3N8); 4 against an avian A/Teal/Hong Kong/w3129(H6N1), 11 against an avian-like A/Hong Kong/1073/1999(H9N2), and 1 against an avian A/Migrating duck/Hong Kong/MPD268/2007(H10N4) virus. However, all such titers were <1∶80 and none were statistically associated with avian or horse exposures. A number of subjects had evidence of seroconversion to zoonotic viruses, but the 4-fold titer changes were again not associated with avian or horse exposures. As elevated antibodies against seasonal influenza viruses were high during the study period, it seems likely that cross-reacting antibodies against seasonal human influenza viruses were a cause of the low-level seroreactivity against AIV or EIV. Despite the presence of AIV and EIV circulating among wild birds and horses in Mongolia, there was little evidence of AIV or EIV infection in this prospective study

  6. Influenza A(H5N8) Virus Similar to Strain in Korea Causing Highly Pathogenic Avian Influenza in Germany.

    PubMed

    Harder, Timm; Maurer-Stroh, Sebastian; Pohlmann, Anne; Starick, Elke; Höreth-Böntgen, Detlef; Albrecht, Karin; Pannwitz, Gunter; Teifke, Jens; Gunalan, Vithiagaran; Lee, Raphael T C; Sauter-Louis, Carola; Homeier, Timo; Staubach, Christoph; Wolf, Carola; Strebelow, Günter; Höper, Dirk; Grund, Christian; Conraths, Franz J; Mettenleiter, Thomas C; Beer, Martin

    2015-05-01

    Highly pathogenic avian influenza (H5N8) virus, like the recently described H5N8 strain from Korea, was detected in November 2014 in farmed turkeys and in a healthy common teal (Anas crecca) in northeastern Germany. Infected wild birds possibly introduced this virus. PMID:25897703

  7. Assessment of Antiviral Properties of Peramivir against H7N9 Avian Influenza Virus in an Experimental Mouse Model

    PubMed Central

    Farooqui, Amber; Huang, Linxi; Wu, Suwu; Cai, Yingmu; Su, Min; Lin, Pengzhou; Chen, Weihong; Fang, Xibin; Zhang, Li; Liu, Yisu; Zeng, Tiansheng; Paquette, Stephane G.; Khan, Adnan; Kelvin, Alyson A.

    2015-01-01

    The H7N9 influenza virus causes a severe form of disease in humans. Neuraminidase inhibitors, including oral oseltamivir and injectable peramivir, are the first choices of antiviral treatment for such cases; however, the clinical efficacy of these drugs is questionable. Animal experimental models are essential for understanding the viral replication kinetics under the selective pressure of antiviral agents. This study demonstrates the antiviral activity of peramivir in a mouse model of H7N9 avian influenza virus infection. The data show that repeated administration of peramivir at 30 mg/kg of body weight successfully eradicated the virus from the respiratory tract and extrapulmonary tissues during the acute response, prevented clinical signs of the disease, including neuropathy, and eventually protected mice against lethal H7N9 influenza virus infection. Early treatment with peramivir was found to be associated with better disease outcomes. PMID:26369969

  8. Environmental transmission scrambles coexistence patterns of avian influenza viruses.

    PubMed

    Roche, Benjamin; Rohani, Pejman

    2010-06-01

    Despite the recent accumulation of theoretical and empirical studies on avian influenza viruses (AIVs), the interactions among the diverse pool of strains remain poorly understood. One potential reason is multiple transmission routes. In this paper, we explore the behavior of a two-strain mathematical model of AIV dynamics with lifelong immunity to understand how the combination of direct and environmental transmission (via a persistent viral reservoir) determines strains coexistence and dominance. We find that coexistence requires the magnitude of basic reproductive ratios of the strains to be identical for each transmission route (R(0)(dir) and R(0)(env)) when cross-immunity is assumed to be perfect. Coexistence may be also possible when one strain is only directly transmitted and the contribution by environmental transmission is high. When we relax this assumption, the level of cross-protection does not modify coexistence criteria when strains are mainly environmentally transmitted, in contrast to the case where direct transmission dominates. Finally, when competitive exclusion is observed, the strain with the largest contribution from direct transmission outcompetes the other through competition for viral particle acquisition. Overall, we conclude that environmental transmission can affect the patterns of coexistence predicted by direct transmission models in complex ways. PMID:21352779

  9. Electronic microarray assays for avian influenza and Newcastle disease virus.

    PubMed

    Lung, Oliver; Beeston, Anne; Ohene-Adjei, Samuel; Pasick, John; Hodko, Dalibor; Hughes, Kimberley Burton; Furukawa-Stoffer, Tara; Fisher, Mathew; Deregt, Dirk

    2012-11-01

    Microarrays are suitable for multiplexed detection and typing of pathogens. Avian influenza virus (AIV) is currently classified into 16 H (hemagglutinin) and 9 N (neuraminidase) subtypes, whereas Newcastle disease virus (NDV) strains differ in virulence and are broadly classified into high and low pathogenicity types. In this study, three assays for detection and typing of poultry viruses were developed on an automated microarray platform: a multiplex assay for simultaneous detection of AIV and detection and pathotyping of NDV, and two separate assays for differentiating all AIV H and N subtypes. The AIV-NDV multiplex assay detected all strains in a 63 virus panel, and accurately typed all high pathogenicity NDV strains tested. A limit of detection of 10(1)-10(3) TCID(50)/mL and 200-400 EID(50)/mL was obtained for NDV and AIV, respectively. The AIV typing assays accurately typed all 41 AIV strains and a limit of detection of 4-200 EID(50)/mL was obtained. Assay validation showed that the microarray assays were generally comparable to real-time RT-PCR. However, the AIV typing microarray assays detected more positive clinical samples than the AIV matrix real-time RT-PCR, and also provided information regarding the subtype. The AIV-NDV multiplex and AIV H typing microarray assays detected mixed infections and could be useful for detection and typing of AIV and NDV.

  10. Impact of avian influenza on village poultry production globally.

    PubMed

    Alders, Robyn; Awuni, Joseph Adongo; Bagnol, Brigitte; Farrell, Penny; de Haan, Nicolene

    2014-01-01

    Village poultry and their owners were frequently implicated in disease transmission in the early days of the highly pathogenic avian influenza (HPAI) H5N1 pandemic. With improved understanding of the epidemiology of the disease, it was recognized that village poultry raised under extensive conditions pose less of a threat than intensively raised poultry of homogeneous genetic stock with poor biosecurity. This paper provides an overview of village poultry production and the multiple ways that the HPAI H5N1 pandemic has impacted on village poultry, their owners, and the traders whose livelihoods are intimately linked to these birds. It reviews impact in terms of gender and cultural issues; food security; village poultry value chains; approaches to biosecurity; marketing; poultry disease prevention and control; compensation; genetic diversity; poultry as part of livelihood strategies; and effective communication. It concludes on a positive note that there is growing awareness amongst animal health providers of the importance of facilitating culturally sensitive dialogue to develop HPAI prevention and control options. PMID:24136383

  11. First Characterization of Avian Influenza Viruses from Greenland 2014.

    PubMed

    Hartby, Christina Marie; Krog, Jesper Schak; Merkel, Flemming; Holm, Elisabeth; Larsen, Lars Erik; Hjulsager, Charlotte Kristiane

    2016-05-01

    In late February 2014, unusually high numbers of wild thick-billed murres (Uria lomvia) were found dead on the coast of South Greenland. To investigate the cause of death, 45 birds were submitted for laboratory examination in Denmark. Avian influenza viruses (AIVs) with subtypes H11N2 and low pathogenic H5N1 were detected in some of the birds. Characterization of the viruses by full genome sequencing revealed that all the gene segments belonged to the North American lineage of AIVs. The seemingly sparse and mixed subtype occurrence of low pathogenic AIVs in these birds, in addition to the emaciated appearance of the birds, suggests that the murre die-off was due to malnutrition as a result of sparse food availability or inclement weather. Here we present the first characterization of AIVs isolated in Greenland, and our results support the idea that wild birds in Greenland may be involved in the movement of AIV between North America and Europe.

  12. Impact of avian influenza on village poultry production globally.

    PubMed

    Alders, Robyn; Awuni, Joseph Adongo; Bagnol, Brigitte; Farrell, Penny; de Haan, Nicolene

    2014-01-01

    Village poultry and their owners were frequently implicated in disease transmission in the early days of the highly pathogenic avian influenza (HPAI) H5N1 pandemic. With improved understanding of the epidemiology of the disease, it was recognized that village poultry raised under extensive conditions pose less of a threat than intensively raised poultry of homogeneous genetic stock with poor biosecurity. This paper provides an overview of village poultry production and the multiple ways that the HPAI H5N1 pandemic has impacted on village poultry, their owners, and the traders whose livelihoods are intimately linked to these birds. It reviews impact in terms of gender and cultural issues; food security; village poultry value chains; approaches to biosecurity; marketing; poultry disease prevention and control; compensation; genetic diversity; poultry as part of livelihood strategies; and effective communication. It concludes on a positive note that there is growing awareness amongst animal health providers of the importance of facilitating culturally sensitive dialogue to develop HPAI prevention and control options.

  13. Experience in control of avian influenza in Asia.

    PubMed

    Sims, L D

    2007-01-01

    Highly pathogenic H5N1 avian influenza viruses have been circulating in Asia for over ten years, providing considerable experience on which to base appropriate long-term strategies for their control. Experience in Hong Kong SAR demonstrates that existing production and marketing practices should be changed and a range of parallel measures used. It also shows the extent of surveillance required to ensure continuing freedom from infection. Certain high-risk practices should be changed or otherwise overcome in order to control and prevent disease, including intensive rearing of large numbers of poultry in premises without biosecurity commensurate with the level of risk for exposure; complex market chains involving many smallholders selling poultry through large numbers of transporters and middlemen in poorly regulated live poultry markets; and rearing of large numbers of ducks outdoors. These high-risk practices are compounded by weak veterinary services and poor reporting systems. In many parts of Asia, these methods of rearing and marketing are an integral way of life, support the poorest members of the community or cannot be changed quickly without severe socioeconomic consequences. The gains made so far will be ephemeral unless there is a shift from an emergency focus to one of consolidation in which these high-risk practices are identified and sustainable measures implemented to minimize the risks they pose, taking account of the socioeconomic effects of interventions. Vaccination will play a key role, as it currently does in China and Viet Nam.

  14. Use of vaccination in avian influenza control and eradication.

    PubMed

    Marangon, S; Cecchinato, M; Capua, I

    2008-01-01

    Vaccination against avian influenza (AI) infections caused by viruses of the H5 and H7 subtypes has been used in several occasions in recent years with the general objective of controlling and in some cases eradicating the disease. To contain AI infections effectively, vaccination should only be used as part of a comprehensive control strategy that also includes biosecurity, quarantine, surveillance, education, and elimination of infected and at-risk poultry. Although properly used, potent AI vaccines can prevent disease and death, increase resistance to infection, reduce virus replication and shedding, and reduce viral transmission, they cannot completely prevent AI virus replication. A wide variety of vaccines against AI has been developed and tested in experimental conditions, but only inactivated whole AI virus vaccines and recombinant H5-AI vaccines have been licensed and widely used in various countries. AI vaccination programmes should be adapted to local conditions to guarantee efficacy and sustainability. In particular, vaccination programmes should be modulated in diverse situations according to the virus strain involved, the characteristics of the poultry producing sector, the capacity of the veterinary infrastructure, and the availability of adequate resources. Based on the eco-epidemiological situation in the affected region/area/compartment and the assessment of the risk of AI introduction, different vaccination strategies could be implemented to control AI: (i) routine vaccination performed in endemic areas; (ii) emergency vaccination in the face of an epidemic; and (iii) preventative vaccination carried out whenever a high risk of virus incursion is identified.

  15. Avian influenza virus investigation in wild bobwhite quail from Texas.

    PubMed

    Ferro, Pamela J; Khan, Owais; Vuong, Christine; Reddy, Sanjay M; LaCoste, Lloyd; Rollins, Dale; Lupiani, Blanca

    2012-12-01

    The objective of this study was to determine the prevalence of avian influenza viruses (AIV) in bobwhite quail (Colinus virginianus) populations from the rolling plains of Texas, U. S. A. A total of 1320 swab samples (652 tracheal swabs and 668 cloacal swabs) and 44 serum samples were collected from wild-captured or hunter-harvested bobwhite quail from November 2009 to April 2011 at the Rolling Planes Quail Research Ranch, Fisher County, Texas, U. S. A. The presence of AIV in the swabs was determined by real-time reverse-transcription-PCR (rRT-PCR) and all samples positive or suspicious by rRT-PCR were further processed for virus isolation in embryonated chicken eggs. A total of 18 (1.4%) swab samples tested positive for AIV by rRT-PCR (cycle threshold [Ct] values < 35): 13 cloacal swabs (1.9%) and 5 tracheal swabs (0.8%). In addition, 100 (7.6%) swab samples were considered suspicious (Ct values 35.1-40): 69 cloacal swabs (10.3%) and 31 tracheal swabs (4.7%). No virus was isolated from any of the rRT-PCR-positive or suspicious samples tested. Additionally, 44 serum samples were screened for AIV antibodies and were negative. The results presented here indicate low prevalence of AIV in wild populations of bobwhite quail.

  16. Migration strategy affects avian influenza dynamics in mallards (Anas platyrhynchos).

    PubMed

    Hill, Nichola J; Takekawa, John Y; Ackerman, Joshua T; Hobson, Keith A; Herring, Garth; Cardona, Carol J; Runstadler, Jonathan A; Boyce, Walter M

    2012-12-01

    Studies of pathogen transmission typically overlook that wildlife hosts can include both migrant and resident populations when attempting to model circulation. Through the application of stable isotopes in flight feathers, we estimated the migration strategy of mallards (Anas platyrhynchos) occurring on California wintering grounds. Our study demonstrates that mallards- a principal host of avian influenza virus (AIV) in nature, contribute differently to virus gene flow depending on migration strategy. No difference in AIV prevalence was detected between resident (9.6%), intermediate-distance (9.6%) and long-distance migrants (7.4%). Viral diversity among the three groups was also comparable, possibly owing to viral pool mixing when birds converge at wetlands during winter. However, migrants and residents contributed differently to the virus gene pool at wintering wetlands. Migrants introduced virus from northern breeding grounds (Alaska and the NW Pacific Rim) into the wintering population, facilitating gene flow at continental scales, but circulation of imported virus appeared to be limited. In contrast, resident mallards acted as AIV reservoirs facilitating year-round circulation of limited subtypes (i.e. H5N2) at lower latitudes. This study supports a model of virus exchange in temperate regions driven by the convergence of wild birds with separate geographic origins and exposure histories. PMID:22971007

  17. Migration strategy affects avian influenza dynamics in mallards (Anas platyrhynchos).

    USGS Publications Warehouse

    Takekawa, John Y.; Hill, Nichola J.; Ackerman, Joshua T.; Herring, Garth; Hobson, Keith; Cardona, Carol J.; Runstadler, Jonathan; Boyce, Walter M.

    2012-01-01

    Studies of pathogen transmission typically overlook that wildlife hosts can include both migrant and resident populations when attempting to model circulation. Through the application of stable isotopes in flight feathers, we estimated the migration strategy of mallards (Anas platyrhynchos) occurring on California wintering grounds. Our study demonstrates that mallards- a principal host of avian influenza virus (AIV) in nature, contribute differently to virus gene flow depending on migration strategy. No difference in AIV prevalence was detected between resident (9.6%), intermediate-distance (9.6%) and long-distance migrants (7.4%). Viral diversity among the three groups was also comparable, possibly owing to viral pool mixing when birds converge at wetlands during winter. However, migrants and residents contributed differently to the virus gene pool at wintering wetlands. Migrants introduced virus from northern breeding grounds (Alaska and the NW Pacific Rim) into the wintering population, facilitating gene flow at continental scales, but circulation of imported virus appeared to be limited. In contrast, resident mallards acted as AIV reservoirs facilitating year-round circulation of limited subtypes (i.e. H5N2) at lower latitudes. This study supports a model of virus exchange in temperate regions driven by the convergence of wild birds with separate geographic origins and exposure histories.

  18. Migration strategy affects avian influenza dynamics in mallards (Anas platyrhynchos).

    PubMed

    Hill, Nichola J; Takekawa, John Y; Ackerman, Joshua T; Hobson, Keith A; Herring, Garth; Cardona, Carol J; Runstadler, Jonathan A; Boyce, Walter M

    2012-12-01

    Studies of pathogen transmission typically overlook that wildlife hosts can include both migrant and resident populations when attempting to model circulation. Through the application of stable isotopes in flight feathers, we estimated the migration strategy of mallards (Anas platyrhynchos) occurring on California wintering grounds. Our study demonstrates that mallards- a principal host of avian influenza virus (AIV) in nature, contribute differently to virus gene flow depending on migration strategy. No difference in AIV prevalence was detected between resident (9.6%), intermediate-distance (9.6%) and long-distance migrants (7.4%). Viral diversity among the three groups was also comparable, possibly owing to viral pool mixing when birds converge at wetlands during winter. However, migrants and residents contributed differently to the virus gene pool at wintering wetlands. Migrants introduced virus from northern breeding grounds (Alaska and the NW Pacific Rim) into the wintering population, facilitating gene flow at continental scales, but circulation of imported virus appeared to be limited. In contrast, resident mallards acted as AIV reservoirs facilitating year-round circulation of limited subtypes (i.e. H5N2) at lower latitudes. This study supports a model of virus exchange in temperate regions driven by the convergence of wild birds with separate geographic origins and exposure histories.

  19. Pathogenesis and pathobiology of avian influenza virus infection in birds.

    PubMed

    Pantin-Jackwood, M J; Swayne, D E

    2009-04-01

    Avian influenza (AI) viruses vary in their ability to produce infection, disease and death in different bird species. Based on the pathobiological effect in chickens, AI viruses (AIV) are categorised as low pathogenic (LPAIV) or highly pathogenic (HPAIV). Typically, LPAIV cause asymptomatic infections in wild aquatic birds, but when introduced into domesticated poultry, infections may be asymptomatic or produce clinical signs and lesions reflecting pathophysiological damage to the respiratory, digestive and reproductive systems. The HPAIV have primarily been seen in gallinaceous poultry, producing high morbidity and mortality, and systemic disease with necrosis and inflammation in multiple visceral organs, nervous and cardiovascular systems, and the integument. Although HPAIV have rarely infected domestic waterfowl or wild birds, the Eurasian-African H5N1 HPAIV have evolved over the past decade with the unique capacity to infect and cause disease in domestic ducks and wild birds, producing a range of syndromes including asymptomatic respiratory and digestive tract infections; systemic disease limited to two or three critical organs, usually the brain, heart and pancreas; and severe disseminated infection and death as seen in gallinaceous poultry. Although experimental studies using intranasal inoculation have produced infection in a variety of wild bird species, the inefficiency of contact transmission in some of them, for example, passerines and Columbiformes, suggests they are unlikely to be a reservoir for the viruses, while others such as some wild Anseriformes, can be severely affected and could serve as a dissemination host over intermediate distances.

  20. Evolution of an Eurasian avian-like influenza virus in naïve and vaccinated pigs.

    PubMed

    Murcia, Pablo R; Hughes, Joseph; Battista, Patrizia; Lloyd, Lucy; Baillie, Gregory J; Ramirez-Gonzalez, Ricardo H; Ormond, Doug; Oliver, Karen; Elton, Debra; Mumford, Jennifer A; Caccamo, Mario; Kellam, Paul; Grenfell, Bryan T; Holmes, Edward C; Wood, James L N

    2012-01-01

    Influenza viruses are characterized by an ability to cross species boundaries and evade host immunity, sometimes with devastating consequences. The 2009 pandemic of H1N1 influenza A virus highlights the importance of pigs in influenza emergence, particularly as intermediate hosts by which avian viruses adapt to mammals before emerging in humans. Although segment reassortment has commonly been associated with influenza emergence, an expanded host-range is also likely to be associated with the accumulation of specific beneficial point mutations. To better understand the mechanisms that shape the genetic diversity of avian-like viruses in pigs, we studied the evolutionary dynamics of an Eurasian Avian-like swine influenza virus (EA-SIV) in naïve and vaccinated pigs linked by natural transmission. We analyzed multiple clones of the hemagglutinin 1 (HA1) gene derived from consecutive daily viral populations. Strikingly, we observed both transient and fixed changes in the consensus sequence along the transmission chain. Hence, the mutational spectrum of intra-host EA-SIV populations is highly dynamic and allele fixation can occur with extreme rapidity. In addition, mutations that could potentially alter host-range and antigenicity were transmitted between animals and mixed infections were commonplace, even in vaccinated pigs. Finally, we repeatedly detected distinct stop codons in virus samples from co-housed pigs, suggesting that they persisted within hosts and were transmitted among them. This implies that mutations that reduce viral fitness in one host, but which could lead to fitness benefits in a novel host, can circulate at low frequencies. PMID:22693449

  1. Gene flow and competitive exclusion of avian influenza A virus in natural reservoir hosts.

    PubMed

    Bahl, Justin; Vijaykrishna, Dhanasekaran; Holmes, Edward C; Smith, Gavin J D; Guan, Yi

    2009-08-01

    Geographical separation of host species has shaped the avian influenza A virus gene pool into independently evolving Eurasian and American lineages, although phylogenetic evidence for gene flow and reassortment indicates that these lineages also mix on occasion. While the evolutionary dynamics of the avian influenza gene pool have been described, the consequences of gene flow on virus evolution and population structure in this system have not been investigated. Here we show that viral gene flow from Eurasia has led to the replacement of endemic avian influenza viruses in North America, likely through competition for susceptible hosts. This competition is characterized by changes in rates of nucleotide substitution and selection pressures. However, the discontinuous distribution of susceptible hosts may produce long periods of co-circulation of competing virus strains before lineage extinction occurs. These results also suggest that viral competition for host resources may be an important mechanism in disease emergence.

  2. Avian influenza ecology in North Atlantic sea ducks: Not all ducks are created equal

    USGS Publications Warehouse

    Hall, Jeffrey S.; Russell, Robin E.; Franson, J. Christian; Soos, Catherine; Dusek, Robert J.; Allen, R. Bradford; Nashold, Sean W.; Teslaa, Joshua L.; Jónsson, Jón Einar; Ballard, Jennifer R.; Harms, Naomi Jnae; Brown, Justin D.

    2015-01-01

    Wild waterfowl are primary reservoirs of avian influenza viruses (AIV). However the role of sea ducks in the ecology of avian influenza, and how that role differs from freshwater ducks, has not been examined. We obtained and analyzed sera from North Atlantic sea ducks and determined the seroprevalence in those populations. We also tested swab samples from North Atlantic sea ducks for the presence of AIV. We found relatively high serological prevalence (61%) in these sea duck populations but low virus prevalence (0.3%). Using these data we estimated that an antibody half-life of 141 weeks (3.2 years) would be required to attain these prevalences. These findings are much different than what is known in freshwater waterfowl and have implications for surveillance efforts, AIV in marine environments, and the roles of sea ducks and other long-lived waterfowl in avian influenza ecology.

  3. Avian Influenza Ecology in North Atlantic Sea Ducks: Not All Ducks Are Created Equal

    PubMed Central

    Hall, Jeffrey S.; Russell, Robin E.; Franson, J. Christian; Soos, Catherine; Dusek, Robert J.; Allen, R. Bradford; Nashold, Sean W.; TeSlaa, Joshua L.; Jónsson, Jón Eínar; Ballard, Jennifer R.; Harms, Naomi Jane; Brown, Justin D.

    2015-01-01

    Wild waterfowl are primary reservoirs of avian influenza viruses (AIV). However the role of sea ducks in the ecology of avian influenza, and how that role differs from freshwater ducks, has not been examined. We obtained and analyzed sera from North Atlantic sea ducks and determined the seroprevalence in those populations. We also tested swab samples from North Atlantic sea ducks for the presence of AIV. We found relatively high serological prevalence (61%) in these sea duck populations but low virus prevalence (0.3%). Using these data we estimated that an antibody half-life of 141 weeks (3.2 years) would be required to attain these prevalences. These findings are much different than what is known in freshwater waterfowl and have implications for surveillance efforts, AIV in marine environments, and the roles of sea ducks and other long-lived waterfowl in avian influenza ecology. PMID:26677841

  4. Avian Influenza Ecology in North Atlantic Sea Ducks: Not All Ducks Are Created Equal.

    PubMed

    Hall, Jeffrey S; Russell, Robin E; Franson, J Christian; Soos, Catherine; Dusek, Robert J; Allen, R Bradford; Nashold, Sean W; TeSlaa, Joshua L; Jónsson, Jón Eínar; Ballard, Jennifer R; Harms, Naomi Jane; Brown, Justin D

    2015-01-01

    Wild waterfowl are primary reservoirs of avian influenza viruses (AIV). However the role of sea ducks in the ecology of avian influenza, and how that role differs from freshwater ducks, has not been examined. We obtained and analyzed sera from North Atlantic sea ducks and determined the seroprevalence in those populations. We also tested swab samples from North Atlantic sea ducks for the presence of AIV. We found relatively high serological prevalence (61%) in these sea duck populations but low virus prevalence (0.3%). Using these data we estimated that an antibody half-life of 141 weeks (3.2 years) would be required to attain these prevalences. These findings are much different than what is known in freshwater waterfowl and have implications for surveillance efforts, AIV in marine environments, and the roles of sea ducks and other long-lived waterfowl in avian influenza ecology.

  5. Phylogenic analysis of reassorted avian influenza viruses isolated from Korean domestic ducks from 2005 to 2007.

    PubMed

    Kang, Sook Jung; Kim, Heui Man; Kim, Yun Hee; Hwang, Seon Do; Shin, Jin Soo; Ku, Keun Bon; Kim, Hyun Soo; Seo, Sang Heui

    2009-02-01

    Ducks have been regarded as animals that can perpetuate most avian influenza viruses since they generally do not show the clear clinical signs such as death and reduced body weight when they are infected. Here, we characterized two H3N2 and one H3N6 avian influenza viruses isolated from ducks on the local farms in Korea from 2005 to 2007. Genetic analysis of these viruses showed that most segments of isolates except NP genes belonged to Eurasian lineage. NP genes of two H3N2 isolates, A/Duck/Korea/S71/07, and A/Duck/Korea/S72/07 belonged to North American lineage. Our results suggest that the genetic reassortment among avian influenza viruses can occur in domestic ducks.

  6. Detection of avian influenza viruses in wild waterbirds in the Rift Valley of Kenya using fecal sampling.

    PubMed

    Ofula, Victor O; Franklin, Alan B; Root, J Jeffrey; Sullivan, Heather J; Gichuki, Patrick; Makio, Albina; Bulimo, Wallace; Abong'o, Bernard O; Muchai, Muchane; Schnabel, David

    2013-06-01

    Highly pathogenic avian influenza virus A/H5N1 has been reported in 11 African countries. Migratory waterbirds have the potential of introducing A/H5N1 into east Africa through the Rift Valley of Kenya. We present the results of a wild bird surveillance system for A/H5N1 and other avian influenza viruses based on avian fecal sampling in Kenya. We collected 2630 fecal samples in 2008. Viral RNA was extracted from pools of 3-5 fecal samples and analyzed for presence of avian influenza virus RNA by real-time RT-PCR. Twelve (2.3%) of the 516 sample pools were positive for avian influenza virus RNA, 2 of which were subtyped as H4N6 viruses. This is the first report of avian influenza virus in wild birds in Kenya. This study demonstrates the success of this approach in detecting avian influenza virus in wild birds and represents an efficient surveillance system for avian influenza virus in regions with limited resources.

  7. Avian Flu

    SciTech Connect

    Eckburg, Paul

    2006-11-06

    Since 2003, a severe form of H5N1 avian influenza has rapidly spread throughout Asia and Europe, infecting over 200 humans in 10 countries. The spread of H5N1 virus from person-to-person has been rare, thus preventing the emergence of a widespread pandemic. However, this ongoing epidemic continues to pose an important public health threat. Avian flu and its pandemic potential in humans will be discussed.

  8. A Single Dose of an Avian H3N8 Influenza Virus Vaccine Is Highly Immunogenic and Efficacious against a Recently Emerged Seal Influenza Virus in Mice and Ferrets

    PubMed Central

    Baz, Mariana; Paskel, Myeisha; Matsuoka, Yumiko; Zengel, James R.; Cheng, Xing; Treanor, John J.; Jin, Hong

    2015-01-01

    ABSTRACT H3N8 influenza viruses are a commonly found subtype in wild birds, usually causing mild or no disease in infected birds. However, they have crossed the species barrier and have been associated with outbreaks in dogs, pigs, donkeys, and seals and therefore pose a threat to humans. A live attenuated, cold-adapted (ca) H3N8 vaccine virus was generated by reverse genetics using the wild-type (wt) hemagglutinin (HA) and neuraminidase (NA) genes from the A/blue-winged teal/Texas/Sg-00079/2007 (H3N8) (tl/TX/079/07) wt virus and the six internal protein gene segments from the ca influenza A virus vaccine donor strain, A/Ann Arbor/6/60 ca (H2N2), the backbone of the licensed seasonal live attenuated influenza vaccine. One dose of the tl/TX/079/07 ca vaccine induced a robust neutralizing antibody response against the homologous (tl/TX/079/07) and two heterologous influenza viruses, including the recently emerged A/harbor seal/New Hampshire/179629/2011 (H3N8) and A/northern pintail/Alaska/44228-129/2006 (H3N8) viruses, and conferred robust protection against the homologous and heterologous influenza viruses. We also analyzed human sera against the tl/TX/079/07 H3N8 avian influenza virus and observed low but detectable antibody reactivity in elderly subjects, suggesting that older H3N2 influenza viruses confer some cross-reactive antibody. The latter observation was confirmed in a ferret study. The safety, immunogenicity, and efficacy of the tl/TX/079/07 ca vaccine in mice and ferrets support further evaluation of this vaccine in humans for use in the event of transmission of an H3N8 avian influenza virus to humans. The human and ferret serology data suggest that a single dose of the vaccine may be sufficient in older subjects. IMPORTANCE Although natural infection of humans with an avian H3N8 influenza virus has not yet been reported, this influenza virus subtype has already crossed the species barrier and productively infected mammals. Pandemic preparedness is an

  9. PB2-588 V promotes the mammalian adaptation of H10N8, H7N9 and H9N2 avian influenza viruses.

    PubMed

    Xiao, Chencheng; Ma, Wenjun; Sun, Na; Huang, Lihong; Li, Yaling; Zeng, Zhaoyong; Wen, Yijun; Zhang, Zaoyue; Li, Huanan; Li, Qian; Yu, Yuandi; Zheng, Yi; Liu, Shukai; Hu, Pingsheng; Zhang, Xu; Ning, Zhangyong; Qi, Wenbao; Liao, Ming

    2016-01-01

    Human infections with avian influenza H7N9 or H10N8 viruses have been reported in China, raising concerns that they might cause human epidemics and pandemics. However, how these viruses adapt to mammalian hosts is unclear. Here we show that besides the commonly recognized viral polymerase subunit PB2 residue 627 K, other residues including 87E, 292 V, 340 K, 588 V, 648 V, and 676 M in PB2 also play critical roles in mammalian adaptation of the H10N8 virus. The avian-origin H10N8, H7N9, and H9N2 viruses harboring PB2-588 V exhibited higher polymerase activity, more efficient replication in mammalian and avian cells, and higher virulence in mice when compared to viruses with PB2-588 A. Analyses of available PB2 sequences showed that the proportion of avian H9N2 or human H7N9 influenza isolates bearing PB2-588 V has increased significantly since 2013. Taken together, our results suggest that the substitution PB2-A588V may be a new strategy for an avian influenza virus to adapt mammalian hosts. PMID:26782141

  10. Neutrality, cross-immunity and subtype dominance in avian influenza viruses.

    PubMed

    Brown, Vicki L; Drake, John M; Barton, Heather D; Stallknecht, David E; Brown, Justin D; Rohani, Pejman

    2014-01-01

    Avian influenza viruses (AIVs) are considered a threat for their potential to seed human influenza pandemics. Despite their acknowledged importance, there are significant unknowns regarding AIV transmission dynamics in their natural hosts, wild birds. Of particular interest is the difference in subtype dynamics between human and bird populations-in human populations, typically only two or three subtypes cocirculate, while avian populations are capable of simultaneously hosting a multitude of subtypes. One species in particular-ruddy turnstones (Arenaria interpres)--has been found to harbour a very wide range of AIV subtypes, which could make them a key player in the spread of new subtypes in wild bird populations. Very little is known about the mechanisms that drive subtype dynamics in this species, and here we address this gap in our knowledge. Taking advantage of two independent sources of data collected from ruddy turnstones in Delaware Bay, USA, we examine patterns of subtype diversity and dominance at this site. We compare these patterns to those produced by a stochastic, multi-strain transmission model to investigate possible mechanisms that are parsimonious with the observed subtype dynamics. We find, in agreement with earlier experimental work, that subtype differences are unnecessary to replicate the observed dynamics, and that neutrality alone is sufficient. We also evaluate the role of subtype cross-immunity and find that it is not necessary to generate patterns consistent with observations. This work offers new insights into the mechanisms behind subtype diversity and dominance in a species that has the potential to be a key player in AIV dynamics in wild bird populations.

  11. 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

  12. Children, avian influenza H5N1 and preparing for the next pandemic.

    PubMed

    Nicoll, A

    2008-05-01

    The emergence of avian influenza A/H5N1 viruses has driven pandemic preparations to become government priorities across Europe. To date these viruses have remained poorly adapted to humans and the risk of a pandemic based on H5N1 is unquantifiable. However, the risk of a future pandemic is 100%. Preparations are essential and without these many avoidable deaths will occur. Children will be affected at least as much as adults and may play an important role in amplifying transmission. Pharmacological and public health interventions focused on children will save lives through suggested community measures such as pre-emptive closures of schools, and need to be considered carefully, balancing benefits against negative consequences. Child health services will be hugely stressed by any pandemic but also have the potential to save many lives. The challenge will be to deliver core services in the face of major staff illnesses. Detailed local business continuity planning will be essential.

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

    PubMed Central

    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.

    2015-01-01

    Summary 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

  14. Pathobiological features of a novel, highly pathogenic avian influenza A(H5N8) virus.

    PubMed

    Kim, Young-Il; Pascua, Philippe Noriel Q; Kwon, Hyeok-Il; Lim, Gyo-Jin; Kim, Eun-Ha; Yoon, Sun-Woo; Park, Su-Jin; Kim, Se Mi; Choi, Eun-Ji; Si, Young-Jae; Lee, Ok-Jun; Shim, Woo-Sub; Kim, Si-Wook; Mo, In-Pil; Bae, Yeonji; Lim, Yong Taik; Sung, Moon Hee; Kim, Chul-Joong; Webby, Richard J; Webster, Robert G; Choi, Young Ki

    2014-10-01

    The endemicity of highly pathogenic avian influenza (HPAI) A(H5N1) viruses in Asia has led to the generation of reassortant H5 strains with novel gene constellations. A newly emerged HPAI A(H5N8) virus caused poultry outbreaks in the Republic of Korea in 2014. Because newly emerging high-pathogenicity H5 viruses continue to pose public health risks, it is imperative that their pathobiological properties be examined. Here, we characterized A/mallard duck/Korea/W452/2014 (MDk/W452(H5N8)), a representative virus, and evaluated its pathogenic and pandemic potential in various animal models. We found that MDk/W452(H5N8), which originated from the reassortment of wild bird viruses harbored by migratory waterfowl in eastern China, replicated systemically and was lethal in chickens, but appeared to be attenuated, albeit efficiently transmitted, in ducks. Despite predominant attachment to avian-like virus receptors, MDk/W452(H5N8) also exhibited detectable human virus-like receptor binding and replicated in human respiratory tract tissues. In mice, MDk/W452(H5N8) was moderately pathogenic and had limited tissue tropism relative to previous HPAI A(H5N1) viruses. It also induced moderate nasal wash titers in inoculated ferrets; additionally, it was recovered in extrapulmonary tissues and one of three direct-contact ferrets seroconverted without shedding. Moreover, domesticated cats appeared to be more susceptible than dogs to virus infection. With their potential to become established in ducks, continued circulation of A(H5N8) viruses could alter the genetic evolution of pre-existing avian poultry strains. Overall, detailed virological investigation remains a necessity given the capacity of H5 viruses to evolve to cause human illness with few changes in the viral genome. PMID:26038499

  15. Pathobiological features of a novel, highly pathogenic avian influenza A(H5N8) virus

    PubMed Central

    Kim, Young-Il; Pascua, Philippe Noriel Q; Kwon, Hyeok-Il; Lim, Gyo-Jin; Kim, Eun-Ha; Yoon, Sun-Woo; Park, Su-Jin; Kim, Se Mi; Choi, Eun-Ji; Si, Young-Jae; Lee, Ok-Jun; Shim, Woo-Sub; Kim, Si-Wook; Mo, In-Pil; Bae, Yeonji; Lim, Yong Taik; Sung, Moon Hee; Kim, Chul-Joong; Webby, Richard J; Webster, Robert G; Choi, Young Ki

    2014-01-01

    The endemicity of highly pathogenic avian influenza (HPAI) A(H5N1) viruses in Asia has led to the generation of reassortant H5 strains with novel gene constellations. A newly emerged HPAI A(H5N8) virus caused poultry outbreaks in the Republic of Korea in 2014. Because newly emerging high-pathogenicity H5 viruses continue to pose public health risks, it is imperative that their pathobiological properties be examined. Here, we characterized A/mallard duck/Korea/W452/2014 (MDk/W452(H5N8)), a representative virus, and evaluated its pathogenic and pandemic potential in various animal models. We found that MDk/W452(H5N8), which originated from the reassortment of wild bird viruses harbored by migratory waterfowl in eastern China, replicated systemically and was lethal in chickens, but appeared to be attenuated, albeit efficiently transmitted, in ducks. Despite predominant attachment to avian-like virus receptors, MDk/W452(H5N8) also exhibited detectable human virus-like receptor binding and replicated in human respiratory tract tissues. In mice, MDk/W452(H5N8) was moderately pathogenic and had limited tissue tropism relative to previous HPAI A(H5N1) viruses. It also induced moderate nasal wash titers in inoculated ferrets; additionally, it was recovered in extrapulmonary tissues and one of three direct-contact ferrets seroconverted without shedding. Moreover, domesticated cats appeared to be more susceptible than dogs to virus infection. With their potential to become established in ducks, continued circulation of A(H5N8) viruses could alter the genetic evolution of pre-existing avian poultry strains. Overall, detailed virological investigation remains a necessity given the capacity of H5 viruses to evolve to cause human illness with few changes in the viral genome. PMID:26038499

  16. Newly Emergent Highly Pathogenic H5N9 Subtype Avian Influenza A Virus

    PubMed Central

    Yu, Yang; Wang, Xingbo; Jin, Tao; Wang, Hailong; Si, Weiying; Yang, Hui; Wu, Jiusheng; Yan, Yan; Liu, Guang; Sang, Xiaoyu; Wu, Xiaopeng; Gao, Yuwei; Xia, Xianzhu; Yu, Xinfen; Pan, Jingcao; Gao, George F.

    2015-01-01

    ABSTRACT The novel H7N9 avian influenza virus (AIV) was demonstrated to cause severe human respiratory infections in China. Here, we examined poultry specimens from live bird markets linked to human H7N9 infection in Hangzhou, China. Metagenomic sequencing revealed mixed subtypes (H5, H7, H9, N1, N2, and N9). Subsequently, AIV subtypes H5N9, H7N9, and H9N2 were isolated. Evolutionary analysis showed that the hemagglutinin gene of the novel H5N9 virus originated from A/Muscovy duck/Vietnam/LBM227/2012 (H5N1), which belongs to clade 2.3.2.1. The neuraminidase gene of the novel H5N9 virus originated from human-infective A/Hangzhou/1/2013 (H7N9). The six internal genes were similar to those of other H5N1, H7N9, and H9N2 virus strains. The virus harbored the PQRERRRKR/GL motif characteristic of highly pathogenic AIVs at the HA cleavage site. Receptor-binding experiments demonstrated that the virus binds α-2,3 sialic acid but not α-2,6 sialic acid. Identically, pathogenicity experiments also showed that the virus caused low mortality rates in mice. This newly isolated H5N9 virus is a highly pathogenic reassortant virus originating from H5N1, H7N9, and H9N2 subtypes. Live bird markets represent a potential transmission risk to public health and the poultry industry. IMPORTANCE This investigation confirms that the novel H5N9 subtype avian influenza A virus is a reassortant strain originating from H5N1, H7N9, and H9N2 subtypes and is totally different from the H5N9 viruses reported before. The novel H5N9 virus acquired a highly pathogenic H5 gene and an N9 gene from human-infecting subtype H7N9 but caused low mortality rates in mice. Whether this novel H5N9 virus will cause human infections from its avian host and become a pandemic subtype is not known yet. It is therefore imperative to assess the risk of emergence of this novel reassortant virus with potential transmissibility to public health. PMID:26085150

  17. Virulence determinants of avian H5N1 influenza A virus in mammalian and avian hosts: role of the C-terminal ESEV motif in the viral NS1 protein.

    PubMed

    Zielecki, Florian; Semmler, Ilia; Kalthoff, Donata; Voss, Daniel; Mauel, Susanne; Gruber, Achim D; Beer, Martin; Wolff, Thorsten

    2010-10-01

    We assessed the prediction that access of the viral NS1 protein to cellular PDZ domain protein networks enhances the virulence of highly pathogenic avian influenza A viruses. The NS1 proteins of most avian influenza viruses bear the C-terminal ligand sequence Glu-Ser-Glu-Val (ESEV) for PDZ domains present in multiple host proteins, whereas no such motif is found in the NS1 homologues of seasonal human virus strains. Previous analysis showed that a C-terminal ESEV motif increases viral virulence when introduced into the NS1 protein of mouse-adapted H1N1 influenza virus. To examine the role of the PDZ domain ligand motif in avian influenza virus virulence, we generated three recombinants, derived from the prototypic H5N1 influenza A/Vietnam/1203/04 virus, expressing NS1 proteins that either have the C-terminal ESEV motif or the human influenza virus RSKV consensus or bear a natural truncation of this motif, respectively. Cell biological analyses showed strong control of NS1 nuclear migration in infected mammalian and avian cells, with only minor differences between the three variants. The ESEV sequence attenuated viral replication on cultured human, murine, and duck cells but not on chicken fibroblasts. However, all three viruses caused highly lethal infections in mice and chickens, with little difference in viral titers in organs, mean lethal dose, or intravenous pathogenicity index. These findings demonstrate that a PDZ domain ligand sequence in NS1 contributes little to the virulence of H5N1 viruses in these hosts, and they indicate that this motif modulates viral replication in a strain- and host-dependent manner.

  18. Antibody-Dependent Cell-Mediated Cytotoxicity to Hemagglutinin of Influenza A Viruses After Influenza Vaccination in Humans.

    PubMed

    Zhong, Weimin; Liu, Feng; Wilson, Jason R; Holiday, Crystal; Li, Zhu-Nan; Bai, Yaohui; Tzeng, Wen-Pin; Stevens, James; York, Ian A; Levine, Min Z

    2016-04-01

    Background.  Detection of neutralizing antibodies (nAbs) to influenza A virus hemagglutinin (HA) antigens by conventional serological assays is currently the main immune correlate of protection for influenza vaccines However, current prepandemic avian influenza vaccines are poorly immunogenic in inducing nAbs despite considerable protection conferred. Recent studies show that Ab-dependent cell-mediated cytotoxicity (ADCC) to HA antigens are readily detectable in the sera of healthy individuals and patients with influenza infection. Methods.  Virus neutralization and ADCC activities of serum samples from individuals who received either seasonal or a stock-piled H5N1 avian influenza vaccine were evaluated by hemagglutination inhibition assay, microneutralization assay, and an improved ADCC natural killer (NK) cell activation assay. Results.  Immunization with inactivated seasonal influenza vaccine led to strong expansion of both nAbs and ADCC-mediating antibodies (adccAbs) to H3 antigen of the vaccine virus in 24 postvaccination human sera. In sharp contrast, 18 individuals vaccinated with the adjuvanted H5N1 avian influenza vaccine mounted H5-specific antibodies with strong ADCC activities despite moderate virus neutralization capacity. Strength of HA-specific ADCC activities is largely associated with the titers of HA-binding antibodies and not with the fine antigenic specificity of anti-HA nAbs. Conclusions.  Detection of both nAbs and adccAbs may better reflect protective capacity of HA-specific antibodies induced by avian influenza vaccines. PMID:27419174

  19. Wind-Mediated Spread of Low-Pathogenic Avian Influenza Virus into the Environment during Outbreaks at Commercial Poultry Farms

    PubMed Central

    Jonges, Marcel; van Leuken, Jeroen; Wouters, Inge; Koch, Guus; Meijer, Adam; Koopmans, Marion

    2015-01-01

    Avian influenza virus-infected poultry can release a large amount of virus-contaminated droppings that serve as sources of infection for susceptible birds. Much research so far has focused on virus spread within flocks. However, as fecal material or manure is a major constituent of airborne poultry dust, virus-contaminated particulate matter from infected flocks may be dispersed into the environment. We collected samples of suspended particulate matter, or the inhalable dust fraction, inside, upwind and downwind of buildings holding poultry infected with low-pathogenic avian influenza virus, and tested them for the presence of endotoxins and influenza virus to characterize the potential impact of airborne influenza virus transmission during outbreaks at commercial poultry farms. Influenza viruses were detected by RT-PCR in filter-rinse fluids collected up to 60 meters downwind from the barns, but virus isolation did not yield any isolates. Viral loads in the air samples were low and beyond the limit of RT-PCR quantification except for one in-barn measurement showing a virus concentration of 8.48x104 genome copies/m3. Air samples taken outside poultry barns had endotoxin concentrations of ~50 EU/m3 that declined with increasing distance from the barn. Atmospheric dispersion modeling of particulate matter, using location-specific meteorological data for the sampling days, demonstrated a positive correlation between endotoxin measurements and modeled particulate matter concentrations, with an R2 varying from 0.59 to 0.88. Our data suggest that areas at high risk for human or animal exposure to airborne influenza viruses can be modeled during an outbreak to allow directed interventions following targeted surveillance. PMID:25946115

  20. Wind-Mediated Spread of Low-Pathogenic Avian Influenza Virus into the Environment during Outbreaks at Commercial Poultry Farms.

    PubMed

    Jonges, Marcel; van Leuken, Jeroen; Wouters, Inge; Koch, Guus; Meijer, Adam; Koopmans, Marion

    2015-01-01

    Avian influenza virus-infected poultry can release a large amount of virus-contaminated droppings that serve as sources of infection for susceptible birds. Much research so far has focused on virus spread within flocks. However, as fecal material or manure is a major constituent of airborne poultry dust, virus-contaminated particulate matter from infected flocks may be dispersed into the environment. We collected samples of suspended particulate matter, or the inhalable dust fraction, inside, upwind and downwind of buildings holding poultry infected with low-pathogenic avian influenza virus, and tested them for the presence of endotoxins and influenza virus to characterize the potential impact of airborne influenza virus transmission during outbreaks at commercial poultry farms. Influenza viruses were detected by RT-PCR in filter-rinse fluids collected up to 60 meters downwind from the barns, but virus isolation did not yield any isolates. Viral loads in the air samples were low and beyond the limit of RT-PCR quantification except for one in-barn measurement showing a virus concentration of 8.48 x 10(4) genome copies/m(3). Air samples taken outside poultry barns had endotoxin concentrations of ~50 EU/m(3) that declined with increasing distance from the barn. Atmospheric dispersion modeling of particulate matter, using location-specific meteorological data for the sampling days, demonstrated a positive correlation between endotoxin measurements and modeled particulate matter concentrations, with an R(2) varying from 0.59 to 0.88. Our data suggest that areas at high risk for human or animal exposure to airborne influenza viruses can be modeled during an outbreak to allow directed interventions following targeted surveillance.

  1. Avian influenza A virus PB2 promotes interferon type I inducing properties of a swine strain in porcine dendritic cells

    SciTech Connect

    Ocana-Macchi, Manuela; Ricklin, Meret E.; Python, Sylvie; Monika, Gsell-Albert; Stech, Juergen; Stech, Olga; Summerfield, Artur

    2012-05-25

    The 2009 influenza A virus (IAV) pandemic resulted from reassortment of avian, human and swine strains probably in pigs. To elucidate the role of viral genes in host adaptation regarding innate immune responses, we focussed on the effect of genes from an avian H5N1 and a porcine H1N1 IAV on infectivity and activation of porcine GM-CSF-induced dendritic cells (DC). The highest interferon type I responses were achieved by the porcine virus reassortant containing the avian polymerase gene PB2. This finding was not due to differential tropism since all viruses infected DC equally. All viruses equally induced MHC class II, but porcine H1N1 expressing the avian viral PB2 induced more prominent nuclear NF-{kappa}B translocation compared to its parent IAV. The enhanced activation of DC may be detrimental or beneficial. An over-stimulation of innate responses could result in either pronounced tissue damage or increased resistance against IAV reassortants carrying avian PB2.

  2. Riems influenza a typing array (RITA): An RT-qPCR-based low density array for subtyping avian and mammalian influenza a viruses

    PubMed Central

    Hoffmann, Bernd; Hoffmann, Donata; Henritzi, Dinah; Beer, Martin; Harder, Timm C.

    2016-01-01

    Rapid and sensitive diagnostic approaches are of the utmost importance for the detection of humans and animals infected by specific influenza virus subtype(s). Cascade-like diagnostics starting with the use of pan-influenza assays and subsequent subtyping devices are normally used. Here, we demonstrated a novel low density array combining 32 TaqMan® real-time RT-PCR systems in parallel for the specific detection of the haemagglutinin (HA) and neuraminidase (NA) subtypes of avian and porcine hosts. The sensitivity of the newly developed system was compared with that of the pan-influenza assay, and the specificity of all RT-qPCRs was examined using a broad panel of 404 different influenza A virus isolates representing 45 different subtypes. Furthermore, we analysed the performance of the RT-qPCR assays with diagnostic samples obtained from wild birds and swine. Due to the open format of the array, adaptations to detect newly emerging influenza A virus strains can easily be integrated. The RITA array represents a competitive, fast and sensitive subtyping tool that requires neither new machinery nor additional training of staff in a lab where RT-qPCR is already established. PMID:27256976

  3. Antigenic and Molecular Characterization of Avian Influenza A(H9N2) Viruses, Bangladesh

    PubMed Central

    Shanmuganatham, Karthik; Feeroz, Mohammed M.; Jones-Engel, Lisa; Smith, Gavin J.D.; Fourment, Mathieu; Walker, David; McClenaghan, Laura; Alam, S.M. Rabiul; Hasan, M. Kamrul; Seiler, Patrick; Franks, John; Danner, Angie; Barman, Subrata; McKenzie, Pamela; Krauss, Scott; Webby, Richard J.

    2013-01-01

    Human infection with avian influenza A(H9N2) virus was identified in Bangladesh in 2011. Surveillance for influenza viruses in apparently healthy poultry in live-bird markets in Bangladesh during 2008–2011 showed that subtype H9N2 viruses are isolated year-round, whereas highly pathogenic subtype H5N1 viruses are co-isolated with subtype H9N2 primarily during the winter months. Phylogenetic analysis of the subtype H9N2 viruses showed that they are reassortants possessing 3 gene segments related to subtype H7N3; the remaining gene segments were from the subtype H9N2 G1 clade. We detected no reassortment with subtype H5N1 viruses. Serologic analyses of subtype H9N2 viruses from chickens revealed antigenic conservation, whereas analyses of viruses from quail showed antigenic drift. Molecular analysis showed that multiple mammalian-specific mutations have become fixed in the subtype H9N2 viruses, including changes in the hemagglutinin, matrix, and polymerase proteins. Our results indicate that these viruses could mutate to be transmissible from birds to mammals, including humans. PMID:23968540

  4. Linking avian communities and avian influenza ecology in southern Africa using epidemiological functional groups.

    PubMed

    Caron, Alexandre; de Garine-Wichatitsky, Michel; Ndlovu, Mduduzi; Cumming, Graeme S

    2012-01-01

    The ecology of pathogens, and particularly their emergence in multi-host systems, is complex. New approaches are needed to reduce superficial complexities to a level that still allows scientists to analyse underlying and more fundamental processes. One promising approach for simplification is to use an epidemiological-function classification to describe ecological diversity in a way that relates directly to pathogen dynamics. In this article, we develop and apply the epidemiological functional group (EFG) concept to explore the relationships between wild bird communities and avian influenza virus (AIV) in three ecosystems in southern Africa. Using a two year dataset that combined bird counts and bimonthly sampling for AIV, we allocated each bird species to a set of EFGs that captured two overarching epidemiological functions: the capacity of species to maintain AIV in the system, and their potential to introduce the virus. Comparing AIV prevalence between EFGs suggested that the hypothesis that anseriforms (ducks) and charadriiforms (waders) drive AIV epidemiology cannot entirely explain the high prevalence observed in some EFGs. If anseriforms do play an important role in AIV dynamics in each of the three ecosystems, the role of other species in the local maintenance of AIV cannot be ruled out. The EFG concept thus helped us to identify gaps in knowledge and to highlight understudied bird groups that might play a role in AIV epidemiology. In general, the use of EFGs has potential for generating a range of valuable insights in epidemiology, just as functional group approaches have done in ecology. PMID:23101696

  5. Spatial assessment of the potential risk of avian influenza A virus infection in three raptor species in Japan

    PubMed Central

    MORIGUCHI, Sachiko; ONUMA, Manabu; GOKA, Koichi

    2016-01-01

    Avian influenza A, a highly pathogenic avian influenza, is a lethal infection in certain species of wild birds, including some endangered species. Raptors are susceptible to avian influenza, and spatial risk assessment of such species may be valuable for conservation planning. We used the maximum entropy approach to generate potential distribution models of three raptor species from presence-only data for the mountain hawk-eagle Nisaetus nipalensis, northern goshawk Accipiter gentilis and peregrine falcon Falco peregrinus, surveyed during the winter from 1996 to 2001. These potential distribution maps for raptors were superimposed on avian influenza A risk maps of Japan, created from data on incidence of the virus in wild birds throughout Japan from October 2010 to March 2011. The avian influenza A risk map for the mountain hawk-eagle showed that most regions of Japan had a low risk for avian influenza A. In contrast, the maps for the northern goshawk and peregrine falcon showed that their high-risk areas were distributed on the plains along the Sea of Japan and Pacific coast. We recommend enhanced surveillance for each raptor species in high-risk areas and immediate establishment of inspection systems. At the same time, ecological risk assessments that determine factors, such as the composition of prey species, and differential sensitivity of avian influenza A virus between bird species should provide multifaceted insights into the total risk assessment of endangered species. PMID:26972333

  6. Avian influenza, domestic ducks and rice agriculture in Thailand

    PubMed Central

    Gilbert, Marius; Xiao, Xiangming; Chaitaweesub, Prasit; Kalpravidh, Wantanee; Premashthira, Sith; Boles, Stephen; Slingenbergh, Jan

    2008-01-01

    Highly pathogenic avian influenza (HPAI) caused by H5N1 viruses has become a global scale problem which first emerged in southern China and from there spread to other countries in Southeast and East Asia, where it was first confirmed in end 2003. In previous work, geospatial analyses demonstrated that free grazing ducks played critical role in the epidemiology of the disease in Thailand in the winter 2004/2005, both in terms of HPAI emergence and spread. This study explored the geographic association between free grazing duck census counts and current statistics on the spatial distribution of rice crops in Thailand, in particular the crop calendar of rice production. The analysis was carried out using both district level rice statistics and rice distribution data predicted with the aid of remote sensing, using a rice-detection algorithm. The results indicated a strong association between the number of free grazing ducks and the number of months during which second-crop rice harvest takes place, as well as with the rice crop intensity as predicted by remote sensing. These results confirmed that free grazing duck husbandry was strongly driven by agricultural land use and rice crop intensity, and that this later variable can be readily predicted using remote sensing. Analysis of rice cropping patterns may provide an indication of the location of populations of free grazing ducks in other countries with similar mixed duck and rice production systems and less detailed duck census data. Apart from free ranging ducks and rice cropping, the role of hydrology and seasonality of wetlands and water bodies in the HPAI risk analysis is also discussed in relation to the presumed dry season aggregation of wild waterfowl and aquatic poultry offering much scope for virus transmission. PMID:18418464

  7. Cost-benefit analysis of avian influenza control in Nepal.

    PubMed

    Karki, S; Lupiani, B; Budke, C M; Karki, N P S; Rushton, J; Ivanek, R

    2015-12-01

    Numerous outbreaks of highly pathogenic avian influenza A strain H5N1 have occurred in Nepal since 2009 despite implementation of a national programme to control the disease through surveillance and culling of infected poultry flocks. The objective of the study was to use cost-benefit analysis to compare the current control programme (CCP) with the possible alternatives of: i) no intervention (i.e., absence of control measures [ACM]) and ii) vaccinating 60% of the national poultry flock twice a year. In terms of the benefit-cost ratio, findings indicate a return of US $1.94 for every dollar spent in the CCP compared with ACM. The net present value of the CCP versus ACM, i.e., the amount of money saved by implementing the CCP rather than ACM, is US $861,507 (the benefits of CCP [prevented losses which would have occurred under ACM] minus the cost of CCP). The vaccination programme yields a return of US $2.32 for every dollar spent when compared with the CCR The net present value of vaccination versus the CCP is approximately US $12 million. Sensitivity analysis indicated thatthe findings were robust to different rates of discounting, whereas results were sensitive to the assumed market loss and the number of birds affected in the outbreaks under the ACM and vaccination options. Overall, the findings of the study indicate that the CCP is economically superior to ACM, but that vaccination could give greater economic returns and may be a better control strategy. Future research should be directed towards evaluating the financial feasibility and social acceptability of the CCP and of vaccination, with an emphasis on evaluating market reaction to the presence of H5N1 infection in the country.

  8. Cost-benefit analysis of avian influenza control in Nepal.

    PubMed

    Karki, S; Lupiani, B; Budke, C M; Karki, N P S; Rushton, J; Ivanek, R

    2015-12-01

    Numerous outbreaks of highly pathogenic avian influenza A strain H5N1 have occurred in Nepal since 2009 despite implementation of a national programme to control the disease through surveillance and culling of infected poultry flocks. The objective of the study was to use cost-benefit analysis to compare the current control programme (CCP) with the possible alternatives of: i) no intervention (i.e., absence of control measures [ACM]) and ii) vaccinating 60% of the national poultry flock twice a year. In terms of the benefit-cost ratio, findings indicate a return of US $1.94 for every dollar spent in the CCP compared with ACM. The net present value of the CCP versus ACM, i.e., the amount of money saved by implementing the CCP rather than ACM, is US $861,507 (the benefits of CCP [prevented losses which would have occurred under ACM] minus the cost of CCP). The vaccination programme yields a return of US $2.32 for every dollar spent when compared with the CCR The net present value of vaccination versus the CCP is approximately US $12 million. Sensitivity analysis indicated thatthe findings were robust to different rates of discounting, whereas results were sensitive to the assumed market loss and the number of birds affected in the outbreaks under the ACM and vaccination options. Overall, the findings of the study indicate that the CCP is economically superior to ACM, but that vaccination could give greater economic returns and may be a better control strategy. Future research should be directed towards evaluating the financial feasibility and social acceptability of the CCP and of vaccination, with an emphasis on evaluating market reaction to the presence of H5N1 infection in the country. PMID:27044153

  9. Genetically Diverse Low Pathogenicity Avian Influenza A Virus Subtypes Co-Circulate among Poultry in Bangladesh

    PubMed Central

    Gerloff, Nancy A.; Khan, Salah Uddin; Zanders, Natosha; Balish, Amanda; Haider, Najmul; Islam, Ausraful; Chowdhury, Sukanta; Rahman, Mahmudur Ziaur; Haque, Ainul; Hosseini, Parviez; Gurley, Emily S.; Luby, Stephen P.; Wentworth, David E.; Donis, Ruben O.; Sturm-Ramirez, Katharine; Davis, C. Todd

    2016-01-01

    Influenza virus surveillance, poultry outbreak investigations and genomic sequencing were assessed to understand the ecology and evolution of low pathogenicity avian influenza (LPAI) A viruses in Bangladesh from 2007 to 2013. We analyzed 506 avian specimens collected from poultry in live bird markets and backyard flocks to identify influenza A viruses. Virus isolation-positive specimens (n = 50) were subtyped and their coding-complete genomes were sequenced. The most frequently identified subtypes among LPAI isolates were H9N2, H11N3, H4N6, and H1N1. Less frequently detected subtypes included H1N3, H2N4, H3N2, H3N6, H3N8, H4N2, H5N2, H6N1, H6N7, and H7N9. Gene sequences were compared to publicly available sequences using phylogenetic inference approaches. Among the 14 subtypes identified, the majority of viral gene segments were most closely related to poultry or wild bird viruses commonly found in Southeast Asia, Europe, and/or northern Africa. LPAI subtypes were distributed over several geographic locations in Bangladesh, and surface and internal protein gene segments clustered phylogenetically with a diverse number of viral subtypes suggesting extensive reassortment among these LPAI viruses. H9N2 subtype viruses differed from other LPAI subtypes because genes from these viruses consistently clustered together, indicating this subtype is enzootic in Bangladesh. The H9N2 strains identified in Bangladesh were phylogenetically and antigenically related to previous human-derived H9N2 viruses detected in Bangladesh representing a potential source for human infection. In contrast, the circulating LPAI H5N2 and H7N9 viruses were both phylogenetically and antigenically unrelated to H5 viruses identified previously in humans in Bangladesh and H7N9 strains isolated from humans in China. In Bangladesh, domestic poultry sold in live bird markets carried a wide range of LPAI virus subtypes and a high diversity of genotypes. These findings, combined with the seven year

  10. Genetically Diverse Low Pathogenicity Avian Influenza A Virus Subtypes Co-Circulate among Poultry in Bangladesh.

    PubMed

    Gerloff, Nancy A; Khan, Salah Uddin; Zanders, Natosha; Balish, Amanda; Haider, Najmul; Islam, Ausraful; Chowdhury, Sukanta; Rahman, Mahmudur Ziaur; Haque, Ainul; Hosseini, Parviez; Gurley, Emily S; Luby, Stephen P; Wentworth, David E; Donis, Ruben O; Sturm-Ramirez, Katharine; Davis, C Todd

    2016-01-01

    Influenza virus surveillance, poultry outbreak investigations and genomic sequencing were assessed to understand the ecology and evolution of low pathogenicity avian influenza (LPAI) A viruses in Bangladesh from 2007 to 2013. We analyzed 506 avian specimens collected from poultry in live bird markets and backyard flocks to identify influenza A viruses. Virus isolation-positive specimens (n = 50) were subtyped and their coding-complete genomes were sequenced. The most frequently identified subtypes among LPAI isolates were H9N2, H11N3, H4N6, and H1N1. Less frequently detected subtypes included H1N3, H2N4, H3N2, H3N6, H3N8, H4N2, H5N2, H6N1, H6N7, and H7N9. Gene sequences were compared to publicly available sequences using phylogenetic inference approaches. Among the 14 subtypes identified, the majority of viral gene segments were most closely related to poultry or wild bird viruses commonly found in Southeast Asia, Europe, and/or northern Africa. LPAI subtypes were distributed over several geographic locations in Bangladesh, and surface and internal protein gene segments clustered phylogenetically with a diverse number of viral subtypes suggesting extensive reassortment among these LPAI viruses. H9N2 subtype viruses differed from other LPAI subtypes because genes from these viruses consistently clustered together, indicating this subtype is enzootic in Bangladesh. The H9N2 strains identified in Bangladesh were phylogenetically and antigenically related to previous human-derived H9N2 viruses detected in Bangladesh representing a potential source for human infection. In contrast, the circulating LPAI H5N2 and H7N9 viruses were both phylogenetically and antigenically unrelated to H5 viruses identified previously in humans in Bangladesh and H7N9 strains isolated from humans in China. In Bangladesh, domestic poultry sold in live bird markets carried a wide range of LPAI virus subtypes and a high diversity of genotypes. These findings, combined with the seven year

  11. Genetically Diverse Low Pathogenicity Avian Influenza A Virus Subtypes Co-Circulate among Poultry in Bangladesh.

    PubMed

    Gerloff, Nancy A; Khan, Salah Uddin; Zanders, Natosha; Balish, Amanda; Haider, Najmul; Islam, Ausraful; Chowdhury, Sukanta; Rahman, Mahmudur Ziaur; Haque, Ainul; Hosseini, Parviez; Gurley, Emily S; Luby, Stephen P; Wentworth, David E; Donis, Ruben O; Sturm-Ramirez, Katharine; Davis, C Todd

    2016-01-01

    Influenza virus surveillance, poultry outbreak investigations and genomic sequencing were assessed to understand the ecology and evolution of low pathogenicity avian influenza (LPAI) A viruses in Bangladesh from 2007 to 2013. We analyzed 506 avian specimens collected from poultry in live bird markets and backyard flocks to identify influenza A viruses. Virus isolation-positive specimens (n = 50) were subtyped and their coding-complete genomes were sequenced. The most frequently identified subtypes among LPAI isolates were H9N2, H11N3, H4N6, and H1N1. Less frequently detected subtypes included H1N3, H2N4, H3N2, H3N6, H3N8, H4N2, H5N2, H6N1, H6N7, and H7N9. Gene sequences were compared to publicly available sequences using phylogenetic inference approaches. Among the 14 subtypes identified, the majority of viral gene segments were most closely related to poultry or wild bird viruses commonly found in Southeast Asia, Europe, and/or northern Africa. LPAI subtypes were distributed over several geographic locations in Bangladesh, and surface and internal protein gene segments clustered phylogenetically with a diverse number of viral subtypes suggesting extensive reassortment among these LPAI viruses. H9N2 subtype viruses differed from other LPAI subtypes because genes from these viruses consistently clustered together, indicating this subtype is enzootic in Bangladesh. The H9N2 strains identified in Bangladesh were phylogenetically and antigenically related to previous human-derived H9N2 viruses detected in Bangladesh representing a potential source for human infection. In contrast, the circulating LPAI H5N2 and H7N9 viruses were both phylogenetically and antigenically unrelated to H5 viruses identified previously in humans in Bangladesh and H7N9 strains isolated from humans in China. In Bangladesh, domestic poultry sold in live bird markets carried a wide range of LPAI virus subtypes and a high diversity of genotypes. These findings, combined with the seven year

  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. PMID:22958248

  13. Phylogenetic evolution of swine-origin human influenza virus: a pandemic H1N1 2009.

    PubMed

    Kowalczyk, A; Markowska-Daniel, I

    2010-01-01

    The knowledge of the genome constellation in pandemic influenza A virus H1N1 2009 from different countries and different hosts is valuable for monitoring and understanding of the evolution and migration of these strains. The complete genome sequences of selected worldwide distributed influenza A viruses are publicly available and there have been few longitudinal genome studies of human, avian and swine influenza A viruses. All possible to download SIV sequences of influenza A viruses available at GISAID Platform (Global Initiative on Sharing Avian Influenza Data) were analyzed firstly through the web servers of the Influenza Virus Resource in NCBI. Phylogenetic study of circulating human pandemic H1N1 virus indicated that the new variant possesses a distinctive evolutionary trait. There is no one way the pandemic H1N1 have acquired new genes from other distinguishable viruses circulating recently in local human, pig or domestic poultry populations from various geographic regions. The extensive genetic diversity among whole segments present in pandemic H1N1 genome suggests that multiple introduction of virus have taken place during the period 1999-2009. The initial interspecies transmission could have occurred in the long-range past and after it the reassortants steps lead to three lineages: classical SIV prevalent in the North America, avian-like SIV in Europe and avian-like related SIV in Asia. This analysis contributes to the evidence that pigs are not the only hosts playing the role of "mixing vessel", as it was suggested for many years.

  14. [The situation and preventive measures against the spread of avian influenza on the territory of the country].

    PubMed

    Onishchenko, G G

    2007-01-01

    The Russian Federation, as the whole world community, is anxious about the established situation associated with the prevalence of avian influenza and a threat of its pandemic. Today avian influenza is a complex, i.e. medical, veterinary, social, and economic, problem. Since December 2003, the world has notified an avian influenza panepizootic that has covered 54 countries to date. Despite emergency measures to prevent the prevalence of this infection, resulting in the elimination of more than 100 million poultries, the virus has fixed in the natural population of wild birds and gained the capacity to infect human beings, which serves as a guide for considering it a possible predictor of pandemic virus. According to the WHO classification, the Russian Federation is at Step II of an interpandemic period when cases of the disease are not notified among the population; however, the subtype circulating among the animals can cause the disease to sufficient probability. To prevent mass mortality of influenza virus-infected birds and human contagion in the inhabited localities wherein epizootic is seen, the Russian Federation has organized and implemented a package of antiepizootic, veterinary-sanitary, and sanitary-antiepidemic measures, including on-line exchange of information on the epizootic and epidemiological situation with veterinary surveillance bodies; farmstead rounds are made for the early detection of ill persons among human beings, for which an additional medical personnel has been picked out; daily medical monitoring of the population and the workers of poultry factories, wherein poultry death has been recorded, has been organized; the places of annihilation of utilized fallen and forcedly killed poultry are notified; supervision of the sanitary and veterinary state of the market where alive poultry and ornamental birds are sold has been tightened; measures to lay in a stock of chemotherapeutical and chemoprophylactic agents producing an antiinfluenza

  15. Laboratory preparedness in EU/EEA countries for detection of novel avian influenza A(H7N9) virus, May 2013

    PubMed Central

    Broberg, E; Pereyaslov, D; Struelens, M; Palm, D; Meijer, A; Ellis, J; Zambon, M; McCauley, J; Daniels, R

    2015-01-01

    Following human infections with novel avian influenza A(H7N9) viruses in China, the European Centre for Disease Prevention and Control, the World Health Organization (WHO) Regional Office for Europe and the European Reference Laboratory Network for Human Influenza (ERLI-Net) rapidly posted relevant information, including real-time RT-PCR protocols. An influenza RNA sequence-based computational assessment of detection capabilities for this virus was conducted in 32 national influenza reference laboratories in 29 countries, mostly WHO National Influenza Centres participating in the WHO Global Influenza Surveillance and Response System (GISRS). Twenty-seven countries considered their generic influenza A virus detection assay to be appropriate for the novel A(H7N9) viruses. Twenty-two countries reported having containment facilities suitable for its isolation and propagation. Laboratories in 27 countries had applied specific H7 real-time RT-PCR assays and 20 countries had N9 assays in place. Positive control virus RNA was provided by the WHO Collaborating Centre in London to 34 laboratories in 22 countries to allow evaluation of their assays. Performance of the generic influenza A virus detection and H7 and N9 subtyping assays was good in 24 laboratories in 19 countries. The survey showed that ERLI-Net laboratories had rapidly developed and verified good capability to detect the novel A(H7N9) influenza viruses. PMID:24507469

  16. 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

  17. Transmission of Avian Influenza A Viruses Between Animals and People

    MedlinePlus

    ... many different animals, including ducks, chickens, pigs, whales, horses, and seals. However, certain subtypes of influenza A ... pigs, and H7N7 and H3N8 virus infections of horses. Influenza A viruses that typically infect and transmit ...

  18. Controlling highly pathogenic avian influenza outbreaks: An epidemiological and economic model analysis.

    PubMed

    Backer, J A; van Roermund, H J W; Fischer, E A J; van Asseldonk, M A P M; Bergevoet, R H M

    2015-09-01

    Outbreaks of highly pathogenic avian influenza (HPAI) can cause large losses for the poultry sector and for animal disease controlling authorities, as well as risks for animal and human welfare. In the current simulation approach epidemiological and economic models are combined to compare different strategies to control highly pathogenic avian influenza in Dutch poultry flocks. Evaluated control strategies are the minimum EU strategy (i.e., culling of infected flocks, transport regulations, tracing and screening of contact flocks, establishment of protection and surveillance zones), and additional control strategies comprising pre-emptive culling of all susceptible poultry flocks in an area around infected flocks (1 km, 3 km and 10 km) and emergency vaccination of all flocks except broilers around infected flocks (3 km). Simulation results indicate that the EU strategy is not sufficient to eradicate an epidemic in high density poultry areas. From an epidemiological point of view, this strategy is the least effective, while pre-emptive culling in 10 km radius is the most effective of the studied strategies. But these two strategies incur the highest costs due to long duration (EU strategy) and large-scale culling (pre-emptive culling in 10 km radius). Other analysed pre-emptive culling strategies (i.e., in 1 km and 3 km radius) are more effective than the analysed emergency vaccination strategy (in 3 km radius) in terms of duration and size of the epidemics, despite the assumed optimistic vaccination capacity of 20 farms per day. However, the total costs of these strategies differ only marginally. Extending the capacity for culling substantially reduces the duration, size and costs of the epidemic. This study demonstrates the strength of combining epidemiological and economic model analysis to gain insight in a range of consequences and thus to serve as a decision support tool in the control of HPAI epidemics.

  19. Emergence of mammalian species-infectious and -pathogenic avian influenza H6N5 virus with no evidence of adaptation.

    PubMed

    Nam, Jeong-Hyun; Kim, Eun-Ha; Song, Daesub; Choi, Young Ki; Kim, Jeong-Ki; Poo, Haryoung

    2011-12-01

    The migratory waterfowl of the world are considered to be the natural reservoir of influenza A viruses. Of the 16 hemagglutinin subtypes of avian influenza viruses, the H6 subtype is commonly perpetuated in its natural hosts and is of concern due to its potential to be a precursor of highly pathogenic influenza viruses by reassortment. During routine influenza surveillance, we isolated an unconventional H6N5 subtype of avian influenza virus. Experimental infection of mice revealed that this isolate replicated efficiently in the lungs, subsequently spread systemically, and caused lethality. The isolate also productively infected ferrets, with direct evidence of contact transmission, but no disease or transmission was seen in pigs. Although the isolate possessed the conserved receptor-binding site sequences of avian influenza viruses, it exhibited relatively low replication efficiencies in ducks and chickens. Our genetic and molecular analyses of the isolate revealed that its PB1 sequence showed the highest evolutionary relationship to those of highly pathogenic H5N1 avian influenza viruses and that its PA protein had an isoleucine residue at position 97 (a representative virulence marker). Further studies will be required to examine why our isolate has the virologic characteristics of mammalian influenza viruses but the archetypal receptor binding profiles of avian influenza viruses, as well as to determine whether its potential virulence markers (PB1 analogous to those of H5N1 viruses or isoleucine residue at position 97 within PA) could render it highly pathogenic in mice. PMID:21994462

  20. Surveillance of avian influenza viruses in migratory birds in Egypt, 2003-09.

    PubMed

    Soliman, Atef; Saad, Magdi; Elassal, Emad; Amir, Ehab; Plathonoff, Chantal; Bahgat, Verina; El-Badry, Maha; Ahmed, Lu'ay S; Fouda, Mostafa; Gamaleldin, Mohammed; Mohamed, Nahed Abd-Elal; Salyer, Stephanie; Cornelius, Claire; Barthel, Robert

    2012-07-01

    Migratory (particularly aquatic) birds are the major natural reservoirs for type A influenza viruses. However, their role in transmitting highly pathogenic avian influenza (HPAI) viruses is unclear. Egypt is a "funnel" zone of wild bird migration pathways from Central Asia and Europe to Eastern and Central Africa ending in South Africa. We sought to detect and isolate avian influenza viruses in migratory birds in Egypt. During September 2003-February 2009, the US Naval Medical Research Unit Number 3, Cairo, Egypt, in collaboration with the Egyptian Ministry of Environment, obtained cloacal swabs from 7,894 migratory birds captured or shot by hunters in different geographic areas in Egypt. Samples were processed by real-time reverse transcriptase PCR for detection of the influenza A matrix gene. Positive samples were processed for virus isolation in specific-pathogen-free embryonated eggs and isolates were subtyped by PCR and partial sequencing. Ninety-five species of birds were collected. Predominant species were Green-Winged Teal (Anas carolinensis; 32.0%, n=2,528), Northern Shoveler (Anas clypeata; 21.4%, n=1,686), and Northern Pintail (Anas acuta; 11.1%, n=877). Of the 7,894 samples, 745 (9.4%) were positive for the influenza A matrix gene (mainly from the above predominant species). Thirteen of the 745 (1.7%) were H5-positive by PCR (11 were low-pathogenic avian influenza and two were HPAI H5N1). The prevalences of influenza A was among regions were 10-15%, except in Middle Egypt (4%). Thirty-nine influenza isolates were obtained from PCR-positive samples. Seventeen subtypes of avian influenza viruses (including H5N1 and H7N7) were classified from 39 isolates using PCR and partial sequencing. Only one HPAI H5N1 was isolated in February 2006, from a wild resident Great Egret (Ardea alba). No major die-offs or sick migratory birds were detected during the study. We identified avian influenza virus subtypes not previously reported in Egypt. The HPAI H5N1 isolated

  1. 9 CFR 145.15 - Diagnostic surveillance program for low pathogenic avian influenza.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Diagnostic surveillance program for low pathogenic avian influenza. 145.15 Section 145.15 Animals and Animal Products ANIMAL AND PLANT... antigen detection test. Memoranda of understanding or other means must be used to establish testing...

  2. 9 CFR 145.15 - Diagnostic surveillance program for low pathogenic avian influenza.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Diagnostic surveillance program for low pathogenic avian influenza. 145.15 Section 145.15 Animals and Animal Products ANIMAL AND PLANT... antigen detection test. Memoranda of understanding or other means must be used to establish testing...

  3. Genome Wide Host Gene Expression Analysis in Chicken Lungs Infected with Avian Influenza Viruses

    PubMed Central

    Gandhale, Pradeep N.; Kumar, Himanshu; Kulkarni, Diwakar D.

    2016-01-01

    The molecular pathogenesis of avian influenza infection varies greatly with individual bird species and virus strain. The molecular pathogenesis of the highly pathogenic avian influenza virus (HPAIV) or the low pathogenic avian influenza virus (LPAIV) infection in avian species remains poorly understood. Thus, global immune response of chickens infected with HPAI H5N1 (A/duck/India/02CA10/2011) and LPAI H9N2 (A/duck/India/249800/2010) viruses was studied using microarray to identify crucial host genetic components responsive to these infection. HPAI H5N1 virus induced excessive expression of type I IFNs (IFNA and IFNG), cytokines (IL1B, IL18, IL22, IL13, and IL12B), chemokines (CCL4, CCL19, CCL10, and CX3CL1) and IFN stimulated genes (OASL, MX1, RSAD2, IFITM5, IFIT5, GBP 1, and EIF2AK) in lung tissues. This dysregulation of host innate immune genes may be the critical determinant of the severity and the outcome of the influenza infection in chickens. In contrast, the expression levels of most of these genes was not induced in the lungs of LPAI H9N2 virus infected chickens. This study indicated the relationship between host immune genes and their roles in pathogenesis of HPAIV infection in chickens. PMID:27071061

  4. Highly Pathogenic Avian Influenza Virus (H5N1) Isolated from Whooper Swans, Japan

    PubMed Central

    Uchida, Yuko; Mase, Masaji; Yoneda, Kumiko; Kimura, Atsumu; Obara, Tsuyoshi; Kumagai, Seikou; Yamamoto, Yu; Nakamura, Kikuyasu; Tsukamoto, Kenji; Yamaguchi, Shigeo

    2008-01-01

    On April 21, 2008, four whooper swans were found dead at Lake Towada, Akita prefecture, Japan. Highly pathogenic avian influenza virus of the H5N1 subtype was isolated from specimens of the affected birds. The hemagglutinin (HA) gene of the isolate belongs to clade 2.3.2 in the HA phylogenetic tree. PMID:18760011

  5. Avian influenza virus with Hemagglutinin-Neuraminidase combination H8N8, isolated in Russia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study reports the genome sequence of an avian influenza virus (AIV) subtype H8N8 isolated in Russia. The genome analysis shows that all genes belong to AIV Eurasian lineages. The PB2 gene was similar to a Mongolian low pathogenic (LP) AIV H7N1 and a Chinese high pathogenic (HP) AIV H5N2....

  6. H7 avian influenza virus vaccines protect chickens against challenge with antigenically diverse isolates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccination has been a critical tool in the control of some avian influenza viruses (AIV) and has been used routinely in Pakistan to help control sporadic outbreaks of highly pathogenic (HP) H7 AIV since 1995. During that time, several AIV isolates were utilized as inactivated vaccines with varying...

  7. Pathogenesis and transmission of highly pathogenic avian influenza H5Nx in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction Influenza A viruses (IAV) periodically transmit between pigs, people, and birds. If two IAV strains infect the same host, genes can reassort to generate progeny virus with potential to be more infectious or avoid immunity. Pigs pose a risk for such reassortment. Highly pathogenic avian ...

  8. Filter-feeding bivalves can remove avian influenza viruses from water and reduce infectivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) viruses are transmitted within wild aquatic bird populations through an indirect fecal-oral route involving fecal-contaminated water. In this study, the influence of filter-feeding bivalves, Corbicula fluminea, on the infectivity of AI virus in water was examined. A single cla...

  9. 9 CFR 147.9 - Standard test procedures for avian influenza.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... buffered saline (PBS), 0.01M, pH 7.2 (NVSL media #30054 or equivalent). (ii) Agarose (Type II Medium grade... antisera optional). (3) Preparing the avian influenza AGID agar. (i) Weigh 9 gm of agarose and 80 gm of...

  10. 9 CFR 147.9 - Standard test procedures for avian influenza.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... buffered saline (PBS), 0.01M, pH 7.2 (NVSL media #30054 or equivalent). (ii) Agarose (Type II Medium grade... antisera optional). (3) Preparing the avian influenza AGID agar. (i) Weigh 9 gm of agarose and 80 gm of...

  11. Cross reactive cellular immune responses in chickens previously exposed to low pathogenic avian influenza

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) infection in poultry can result in high morbidity and mortality, and negatively affect international trade. Because most AI vaccines used for poultry are inactivated, our knowledge of immunity against AI is based largely on humoral immune responses. In fact, little is known abo...

  12. Characterization of low pathogenicity avian influenza viruses isolated from wild birds in Mongolia 2005 through 2007

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During 2005, 2006 and 2007 2,139 specimens representing 4,077 individual birds of 45 species were tested for avian influenza virus (AIV) as part of a wild bird AIV monitoring program conducted in Mongolia. Samples collected in 2005 were tested by virus isolation directly, samples from 2006 and 2007...

  13. The affect of infectious bursal disease virus on avian influenza virus vaccine efficacy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immunosuppressive viruses are known to affect vaccinal immunity, however the impact of virally induced immunosuppression on avian influenza vaccine efficacy has not been quantified. In order to determine the effect of exposure to infectious bursal disease virus (IBDV) on vaccinal immunity to highly ...

  14. The performance characteristics of lateral flow devices with 2 strains of highly pathogenic avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lateral flow devices (LFD) are commercially available and provide a fast, highly specific, on-site test for avian influenza. Because of the low analytic sensitivity of LFD tests at low virus concentrations, targeted sampling of sick and dead birds has been proposed in order to increase detection pr...

  15. 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.

  16. Avian Influenza Virus with Hemagglutinin-Neuraminidase Combination H8N8, Isolated in Russia.

    PubMed

    Sivay, Mariya V; Sharshov, Kirill A; Pantin-Jackwood, Mary; Muzyka, Vladimir V; Shestopalov, Alexander M

    2014-01-01

    We report the genome sequence of an avian influenza virus (AIV) subtype H8N8, isolated in Russia. The genome analysis shows that all genes belong to AIV Eurasian lineages. The PB2 gene was similar to a Mongolian low-pathogenic (LP) AIV H7N1 and a Chinese high-pathogenic (HP) AIV H5N2.

  17. Highly pathogenic avian influenza virus and generation of novel reassortants, United States, 2014-2015

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asian highly pathogenic avian influenza A(H5N8) viruses spread into North America in 2014 during autumn bird migration. Complete genome sequencing and phylogenetic analysis of 32 H5 viruses identified novel H5N1, H5N2, and H5N8 viruses that emerged in late 2014 through reassortment with North Americ...

  18. Novel Eurasian highly pathogenic avian influenza A H5 viruses in wild birds, Washington, USA, 2014.

    PubMed

    Ip, Hon S; Torchetti, Mia Kim; Crespo, Rocio; Kohrs, Paul; DeBruyn, Paul; Mansfield, Kristin G; Baszler, Timothy; Badcoe, Lyndon; Bodenstein, Barbara; Shearn-Bochsler, Valerie; Killian, Mary Lea; Pedersen, Janice C; Hines, Nichole; Gidlewski, Thomas; DeLiberto, Thomas; Sleeman, Jonathan M

    2015-05-01

    Novel Eurasian lineage avian influenza A(H5N8) virus has spread rapidly and globally since January 2014. In December 2014, H5N8 and reassortant H5N2 viruses were detected in wild birds in Washington, USA, and subsequently in backyard birds. When they infect commercial poultry, these highly pathogenic viruses pose substantial trade issues.

  19. Accumulation and inactivation of avian influenza virus by the filter feeding invertebrate daphnia magna

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The principle mode of avian influenza A virus (AIV) transmission among wild birds is thought to occur via an indirect fecal-oral route, whereby individuals contract the virus from the environment through contact with virus-contaminated water. AIV can remain viable for periods of months to years in w...

  20. Analysis of H7 avian influenza viruses by antigenic cartography and correlation to protection by vaccination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The H7 hemagglutinin subtype one of the most common subtypes of avian influenza virus (AIV) in poultry world wide and since it has the potential to become highly pathogenic it is among the priority subtypes for vaccination. Selection of the optimal vaccine seed strains may now be aided by antigenic...

  1. Avian Influenza (H7N9) Virus Infection in Chinese Tourist in Malaysia, 2014

    PubMed Central

    William, Timothy; Thevarajah, Bharathan; Lee, Shiu Fee; Suleiman, Maria; Jeffree, Mohamad Saffree; Menon, Jayaram; Saat, Zainah; Thayan, Ravindran; Tambyah, Paul Anantharajah

    2015-01-01

    Of the ≈400 cases of avian influenza (H7N9) diagnosed in China since 2003, the only travel-related cases have been in Hong Kong and Taiwan. Detection of a case in a Chinese tourist in Sabah, Malaysia, highlights the ease with which emerging viral respiratory infections can travel globally. PMID:25531078

  2. Global expansion of high pathogenicity avian influenza: implications on prevention and control programs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The H5N1 high pathogenicity avian influenza (HPAI) virus emerged in China during 1996 and has spread to infect poultry and/or wild birds in 63 countries during the past 18 years. The majority of the recent outbreaks of H5N1 HPAI have occurred in Indonesia, Egypt, Vietnam, and Bangladesh, in decreas...

  3. The role of vaccines and vaccination in avian influenza control and eradication

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A comprehensive review of avian influenza (AI) control methods has been completed. From 2002-2010, over 113 billion doses of AI vaccine were used in poultry in 15 countries. The majority of vaccine (over 90%) was used in China while significant amounts were used in Egypt, Indonesia, and Vietnam. ...

  4. Global expansion of high pathogenicity avian influenza: implications on prevention and control programs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The H5N1 high pathogenicity avian influenza (HPAI) virus emerged in China during 1996 and has spread to infect poultry and/or wild birds in 63 countries during the past 18 years. The majority of the recent outbreaks of H5N1 HPAI have occurred in Indonesia, Egypt, Vietnam, and Bangladesh, in decreasi...

  5. Avian influenza virus isolation, propagation and titration in embryonated chicken eggs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) virus is usually isolated, propagated, and titrated in embryonated chickens eggs (ECE). Most any sample type can be accommodated for culture with appropriate processing. Isolation may also be accomplished in cell culture particularly if mammalian lineage isolates are suspected, ...

  6. Paired serologic and polymerase chain reaction analyses of avian influenza prevalence in Alaskan shorebirds

    USGS Publications Warehouse

    Pearce, John M.; Ruthrauff, Daniel R.; Hall, Jeffrey S.

    2012-01-01

    Surveillance has revealed low prevalence of avian influenza viruses (AIV) in shorebirds except Ruddy Turnstones (Arenaria interpres) on the North American Atlantic coast. Similarly, of five species of shorebirds surveyed in Alaska in 2010, Ruddy Turnstones had the highest AIV antibody prevalence; prevalence of AIV RNA was low or zero.

  7. Low pathogenicity notifiable avian influenza (LPNAI) with an emphasis on vaccination programs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There have been 30 epizootics of H5 or H7 high pathogenicity avian influenza (HPAI) from 1959 to early 2012. The largest has been the H5N1 HPAI which began in Guangdong China in 1996, and has affected over 250 million poultry and/or wild birds in 63 countries. For most countries, stamping-out prog...

  8. Impact of emergence of avian influenza in North America and preventative measures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 1959, the world has experienced 39 highly pathogenic avian influenza (HPAI) epizootics with the largest beginning in 1996 in China that spread to affect 70 countries in Asia, Europe and Africa, and recently North America. Eurasian H5N8 and reassortant H5N2 HPAI viruses were identified in USA. ...

  9. Poultry vaccination directed evolution of H9N2 low pathogenicity avian influenza viruses in Korea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Significant economic losses in the poultry industries have resulted from H9N2 low pathogenic avian influenza virus infections across North Africa, the Middle East and Asia. The present study investigated the evolutionary dynamics of H9N2 viruses circulating in Korea from 1996 to 2012. Our analysis o...

  10. H9N2 low pathogenic avian influenza in Pakistan (2012-2015)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Significant economic losses from deaths and decreased egg production have resulted from H9N2 low pathogenic avian influenza virus (LPAIV) infections in poultry across North Africa, the Middle East and Asia. The H9N2 LPAIVs have been endemic in Pakistani poultry since 1996, but no new viruses have be...

  11. Inactivation of avian influenza virus in chicken litter as a potential method to decontaminate poultry houses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Full cleaning and disinfection of a poultry house after an avian influenza virus (AIV) outbreak is expensive and labor intensive. An alternative to full house cleaning and disinfection is to inactivate the virus with high temperatures within the house. Litter in the house normally has a high virus...

  12. Novel Eurasian Highly Pathogenic Avian Influenza A H5 Viruses in Wild Birds, Washington, USA, 2014

    PubMed Central

    Ip, Hon S.; Crespo, Rocio; Kohrs, Paul; DeBruyn, Paul; Mansfield, Kristin G.; Baszler, Timothy; Badcoe, Lyndon; Bodenstein, Barbara; Shearn-Bochsler, Valerie; Killian, Mary Lea; Pedersen, Janice C.; Hines, Nichole; Gidlewski, Thomas; DeLiberto, Thomas; Sleeman, Jonathan M.

    2015-01-01

    Novel Eurasian lineage avian influenza A(H5N8) virus has spread rapidly and globally since January 2014. In December 2014, H5N8 and reassortant H5N2 viruses were detected in wild birds in Washington, USA, and subsequently in backyard birds. When they infect commercial poultry, these highly pathogenic viruses pose substantial trade issues. PMID:25898265

  13. 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...

  14. The avian-origin H3N2 canine influenza virus has limited replication in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A genetically and antigenically distinct H3N2 canine influenza of avian-origin was detected in March of 2015 in Chicago, Illinois. A subsequent outbreak was reported with over 1,000 dogs in the Midwest affected. The potential for canine-to-swine transmission was unknown. Experimental infection in pi...

  15. Development of vaccines for poultry against H5 avian influenza based on turkey herpesvirus vector

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) remains a major threat to public health as well as to the poultry industry. AI vaccines are considered a suitable tool to support AI control programs in combination with other control measures such as good biosecurity and monitoring programs. We constructed recombinant turkey he...

  16. Pathogenicity of reassortant H5N1 highly pathogenic avian influenza viruses in domestic ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pathogenicity of H5N1 highly pathogenic avian influenza (HPAI) viruses in domestic ducks has increased over time. These changes in virulence have been reported with viruses from countries with high population of domestic ducks, including Egypt. In order to understand which viral genes are contri...

  17. Low pathogenic avian influenza (H7N1) transmission between wild ducks and domestic ducks.

    PubMed

    Therkildsen, O R; Jensen, T H; Handberg, K J; Bragstad, K; Jørgensen, P H

    2011-08-01

    This article describes a virological investigation in a mixed flock of ducks and geese following detection of avian influenza virus antibodies in domestic geese. Low pathogenic H7N1 was found in both domestic and wild birds, indicating that transmission of virus was likely to have taken place between these. The importance of implementing and maintaining appropriate biosecurity measures is re-emphasized.

  18. Increased virulence in ducks of H5N1 highly pathogenic avian influenza viruses from Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pathogenicity of H5N1 highly pathogenic avian influenza (HPAI) viruses in domestic ducks has increased over time. These changes in virulence have been reported with viruses from countries with high population of domestic ducks. Since 2006, H5N1 HPAI outbreaks in Egypt have been occurring in po...

  19. Overview of H5N8 avian influenza virus outbreaks – SEPRL research activities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2014, outbreaks of highly pathogenic avian influenza (HPAI) H5N8 in poultry farms have been reported in Korea, Japan, China, Germany, United Kingdom, and the Netherlands. The first outbreak report of this virus was in domestic ducks in the Republic of Korea in January 2014. In Europe, the first...

  20. 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...

  1. Pathogenicity of two Egyptian H5N1 highly pathogenic avian influenza viruses in domestic ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domestic ducks have been implicated in the dissemination and evolution of H5N1 highly pathogenic avian influenza (HPAI) viruses. Interestingly, the pathogenicity of H5N1 HPAI viruses in domestic ducks has increased over time with some viruses producing 100% mortality in ducks. These changes in vir...

  2. Histopathological findings in a critically ill patient with avian influenza A (H7N9).

    PubMed

    Huang, Jin-Bao; Li, Hong-Yan; Liu, Jia-Fu; Lan, Chang-Qing; Lin, Qing-Hua; Chen, Shu-Xing; Zhang, Hong-Ying; Wang, Xin-Hang; Lin, Xu; Pan, Jian-Guang; Weng, Heng

    2015-12-01

    To date, data regarding the pulmonary histopathology of human H7N9 disease are scarce. We herein describe a patient with a severe case of avian influenza A (H7N9). A chest computerized tomography (CT) scan showed diffuse ground-glass opacities and consolidation throughout the lungs. A resection of pulmonary bullae in the right middle lobe was performed by video-assisted thoracic surgery (VATS) based on the extracorporeal membrane oxygenation (ECMO) supportive technique on the 23(rd) day after the onset of symptoms because of a right pneumothorax persistent air leak. The histopathological findings of the resected lung tissue revealed pneumocyte hyperplasia and fibroproliferative changes along with diffuse alveolar damage. Bronchoalveolar lavage fluid (BALF) specimens for influenza A (H7N9) virus were continuously positive for more than three weeks, despite oseltamivir treatment, and continuous viral replication significantly prolonged the course of the disease. The patient's clinical status continuously deteriorated, with the development of refractory hypoxemia due to progressive and rapid lung fibrosis, which was confirmed by the final histological changes observed from a limited post-mortem biopsy of lung tissue. Pre-terminally, he developed multi-organ failure and died on the 39(th) day after symptom onset, despite corticosteroid treatment. PMID:26793388

  3. Mapping risk of avian influenza transmission at the interface of domestic poultry and wild birds

    USGS Publications Warehouse

    Prosser, Diann J.; Hungerford, Laura L.; Erwin, R. Michael; Ottinger, Mary Ann; Takekawa, John Y.; Ellis, Erle C.

    2013-01-01

    Emergence of avian influenza viruses with high lethality to humans, such as the currently circulating highly pathogenic A(H5N1) (emerged in 1996) and A(H7N9) cause serious concern for the global economic and public health sectors. Understanding the spatial and temporal interface between wild and domestic populations, from which these viruses emerge, is fundamental to taking action. This information, however, is rarely considered in influenza risk models, partly due to a lack of data. We aim to identify areas of high transmission risk between domestic poultry and wild waterfowl in China, the epicenter of both viruses. Two levels of models were developed: one that predicts hotspots of novel virus emergence between domestic and wild birds, and one that incorporates H5N1 risk factors, for which input data exists. Models were produced at 1 and 30 km spatial resolution, and two temporal seasons. Patterns of risk varied between seasons with higher risk in the northeast, central-east, and western regions of China during spring and summer, and in the central and southeastern regions during winter. Monte-Carlo uncertainty analyses indicated varying levels of model confidence, with lowest errors in the densely populated regions of eastern and southern China. Applications and limitations of the models are discussed within.

  4. PB2 subunit of avian influenza virus subtype H9N2: a pandemic risk factor.

    PubMed

    Sediri, Hanna; Thiele, Swantje; Schwalm, Folker; Gabriel, Gülsah; Klenk, Hans-Dieter

    2016-01-01

    Avian influenza viruses of subtype H9N2 that are found worldwide are occasionally transmitted to humans and pigs. Furthermore, by co-circulating with other influenza subtypes, they can generate new viruses with the potential to also cause zoonotic infections, as observed in 1997 with H5N1 or more recently with H7N9 and H10N8 viruses. Comparative analysis of the adaptive mutations in polymerases of different viruses indicates that their impact on the phylogenetically related H9N2 and H7N9 polymerases is higher than on the non-related H7N7 and H1N1pdm09 polymerases. Analysis of polymerase reassortants composed of subunits of different viruses demonstrated that the efficient enhancement of polymerase activity by H9N2-PB2 does not depend on PA and PB1. These observations suggest that the PB2 subunit of the H9N2 polymerase has a high adaptive potential and may therefore be an important pandemic risk factor. PMID:26560088

  5. Isolation and phylogenetic analysis of avian-origin European H1N1 swine influenza viruses in Jiangsu, China.

    PubMed

    Zhao, Guo; Pan, Jinjin; Gu, Xiaobing; Lu, Xinlun; Li, Qunhui; Zhu, Jie; Chen, Chaoyang; Duan, Zhiqiang; Xu, Quangang; Wang, Xiaobo; Hu, Shunlin; Liu, Wenbo; Peng, Daxin; Liu, Xiaowen; Wang, Xiaoquan; Liu, Xiufan

    2012-04-01

    Isolates of the A(H1N1)pdm2009 virus were first identified in asymptomatic swine in Jiangsu province, China in January 2010, indicating that the virus has retro-infected swine after circulating through humans in mainland China. The purpose of this study was to determine whether the avian-origin European H1N1 swine influenza virus (SIV) and the A(H1N1)pdm2009 virus are cocirculating in swine in Jiangsu province of China. From May 2010 to May 2011, 1,030 nasal swab samples were collected from healthy swine in Jiangsu province of China and were tested for influenza A H1N1 using reverse transcription-PCR. Fragments of the complete genomes of viruses from the samples that were positive for influenza A H1N1 were sequenced and analysed. A total of 32 avian-origin European H1N1 SIVs were isolated, and no A(H1N1)pdm2009 viruses were identified; full-length genomes of 18 strains were sequenced. The eight gene segments of some of the isolated H1N1 viruses have 99.1-99.8% sequence identity with the human A/Jiangsu/ALS1/2011(H1N1) isolates in the same region. Our study indicates that the avian-origin European H1N1 SIVs remain endemic in swine and have retro-infected humans after circulating through swine, which may present a risk factor for public health.

  6. 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

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

    PubMed

    Young, Sean G; Carrel, Margaret; Malanson, George P; Ali, Mohamed A; Kayali, Ghazi

    2016-01-01

    Human outbreaks with avian influenza have been, so far, constrained by poor viral adaptation to non-avian hosts. This could be overcome via co-infection, whereby two strains share genetic material, allowing new hybrid strains to emerge. Identifying areas where co-infection is most likely can help target spaces for increased surveillance. Ecological niche modeling using remotely-sensed data can be used for this purpose. H5N1 and H9N2 influenza subtypes are endemic in Egyptian poultry. From 2006 to 2015, over 20,000 poultry and wild birds were tested at farms and live bird markets. Using ecological niche modeling we identified environmental, behavioral, and population characteristics of H5N1 and H9N2 niches within Egypt. Niches differed markedly by subtype. The subtype niches were combined to model co-infection potential with known occurrences used for validation. The distance to live bird markets was a strong predictor of co-infection. Using only single-subtype influenza outbreaks and publicly available ecological data, we identified areas of co-infection potential with high accuracy (area under the receiver operating characteristic (ROC) curve (AUC) 0.991).

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

    PubMed

    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

  9. Variant (Swine Origin) Influenza Viruses in Humans

    MedlinePlus

    ... What's this? Submit Button Past Newsletters Variant Influenza Viruses: Background and CDC Risk Assessment and Reporting Language: ... Background CDC Assessment Reporting Background On Variant Influenza Viruses Swine flu viruses do not normally infect humans. ...

  10. Pathogenesis and Phylogenetic Analyses of Two Avian Influenza H7N1 Viruses Isolated from Wild Birds.

    PubMed

    Jin, Hongmei; Wang, Deli; Sun, Jing; Cui, Yanfang; Chen, Guang; Zhang, Xiaolin; Zhang, Jiajie; Li, Xiang; Chai, Hongliang; Gao, Yuwei; Li, Yanbing; Hua, Yuping

    2016-01-01

    The emergence of human infections with a novel H7N9 influenza strain has raised global concerns about a potential human pandemic. To further understand the character of other influenza viruses of the H7 subtype, we selected two H7N1 avian influenza viruses (AIVs) isolated from wild birds during routine surveillance in China: A/Baer's Pochard/Hunan/414/2010 (BP/HuN/414/10) (H7N1) and A/Common Pochard/Xianghai/420/2010 (CP/XH/420/10) (H7N1). To better understand the molecular characteristics of these two isolated H7N1 viruses, we sequenced and phylogenetically analyzed their entire genomes. The results showed that the two H7N1 strains belonged to a Eurasian branch, originating from a common ancestor. Phylogenetic analysis of their hemagglutinin (HA) genes showed that BP/HuN/414/10 and CP/XH/420/10 have a more distant genetic relationship with A/Shanghai/13/2013 (H7N9), with similarities of 91.6 and 91.4%, respectively. To assess the replication and pathogenicity of these viruses in different hosts, they were inoculated in chickens, ducks and mice. Although, both CP/XH/420/10 and BP/HuN/414/10 can infect chickens, ducks and mice, they exhibited different replication capacities in these animals. The results of this study demonstrated that two low pathogenic avian influenza (LPAI) H7N1 viruses of the Eurasian branch could infect mammals and may even have the potential to infect humans. Therefore, it is important to monitor H7 viruses in both domestic and wild birds.

  11. Pathogenesis and Phylogenetic Analyses of Two Avian Influenza H7N1 Viruses Isolated from Wild Birds.

    PubMed

    Jin, Hongmei; Wang, Deli; Sun, Jing; Cui, Yanfang; Chen, Guang; Zhang, Xiaolin; Zhang, Jiajie; Li, Xiang; Chai, Hongliang; Gao, Yuwei; Li, Yanbing; Hua, Yuping

    2016-01-01

    The emergence of human infections with a novel H7N9 influenza strain has raised global concerns about a potential human pandemic. To further understand the character of other influenza viruses of the H7 subtype, we selected two H7N1 avian influenza viruses (AIVs) isolated from wild birds during routine surveillance in China: A/Baer's Pochard/Hunan/414/2010 (BP/HuN/414/10) (H7N1) and A/Common Pochard/Xianghai/420/2010 (CP/XH/420/10) (H7N1). To better understand the molecular characteristics of these two isolated H7N1 viruses, we sequenced and phylogenetically analyzed their entire genomes. The results showed that the two H7N1 strains belonged to a Eurasian branch, originating from a common ancestor. Phylogenetic analysis of their hemagglutinin (HA) genes showed that BP/HuN/414/10 and CP/XH/420/10 have a more distant genetic relationship with A/Shanghai/13/2013 (H7N9), with similarities of 91.6 and 91.4%, respectively. To assess the replication and pathogenicity of these viruses in different hosts, they were inoculated in chickens, ducks and mice. Although, both CP/XH/420/10 and BP/HuN/414/10 can infect chickens, ducks and mice, they exhibited different replication capacities in these animals. The results of this study demonstrated that two low pathogenic avian influenza (LPAI) H7N1 viruses of the Eurasian branch could infect mammals and may even have the potential to infect humans. Therefore, it is important to monitor H7 viruses in both domestic and wild birds. PMID:27458455

  12. Pathogenesis and Phylogenetic Analyses of Two Avian Influenza H7N1 Viruses Isolated from Wild Birds

    PubMed Central

    Jin, Hongmei; Wang, Deli; Sun, Jing; Cui, Yanfang; Chen, Guang; Zhang, Xiaolin; Zhang, Jiajie; Li, Xiang; Chai, Hongliang; Gao, Yuwei; Li, Yanbing; Hua, Yuping

    2016-01-01

    The emergence of human infections with a novel H7N9 influenza strain has raised global concerns about a potential human pandemic. To further understand the character of other influenza viruses of the H7 subtype, we selected two H7N1 avian influenza viruses (AIVs) isolated from wild birds during routine surveillance in China: A/Baer's Pochard/Hunan/414/2010 (BP/HuN/414/10) (H7N1) and A/Common Pochard/Xianghai/420/2010 (CP/XH/420/10) (H7N1). To better understand the molecular characteristics of these two isolated H7N1 viruses, we sequenced and phylogenetically analyzed their entire genomes. The results showed that the two H7N1 strains belonged to a Eurasian branch, originating from a common ancestor. Phylogenetic analysis of their hemagglutinin (HA) genes showed that BP/HuN/414/10 and CP/XH/420/10 have a more distant genetic relationship with A/Shanghai/13/2013 (H7N9), with similarities of 91.6 and 91.4%, respectively. To assess the replication and pathogenicity of these viruses in different hosts, they were inoculated in chickens, ducks and mice. Although, both CP/XH/420/10 and BP/HuN/414/10 can infect chickens, ducks and mice, they exhibited different replication capacities in these animals. The results of this study demonstrated that two low pathogenic avian influenza (LPAI) H7N1 viruses of the Eurasian branch could infect mammals and may even have the potential to infect humans. Therefore, it is important to monitor H7 viruses in both domestic and wild birds. PMID:27458455

  13. Antigenic Characterization of Recombinant Hemagglutinin Proteins Derived from Different Avian Influenza Virus Subtypes

    PubMed Central

    Mueller, Matthias; Renzullo, Sandra; Brooks, Roxann; Ruggli, Nicolas; Hofmann, Martin A.

    2010-01-01

    Since the advent of highly pathogenic variants of avian influenza virus (HPAIV), the main focus of avian influenza research has been the characterization and detection of HPAIV hemagglutinin (HA) from H5 and H7 subtypes. However, due to the high mutation and reassortation rate of influenza viruses, in theory any influenza strain may acquire increased pathogenicity irrespective of its subtype. A comprehensive antigenic characterization of influenza viruses encompassing all 16 HA and 9 neuraminidase subtypes will provide information useful for the design of differential diagnostic tools, and possibly, vaccines. We have expressed recombinant HA proteins from 3 different influenza virus HA subtypes in the baculovirus system. These proteins were used to generate polyclonal rabbit antisera, which were subsequently employed in epitope scanning analysis using peptide libraries spanning the entire HA. Here, we report the identification and characterization of linear, HA subtype-specific as well as inter subtype-conserved epitopes along the HA proteins. Selected subtype-specific epitopes were shown to be suitable for the differentiation of anti-HA antibodies in an ELISA. PMID:20140098

  14. Infectivity and Transmissibility of Avian H9N2 Influenza Viruses in Pigs

    PubMed Central

    Wang, Jia; Wu, Maocai; Hong, Wenshan; Fan, Xiaohui; Chen, Rirong; Zheng, Zuoyi; Zeng, Yu; Huang, Ren; Zhang, Yu; Lam, Tommy Tsan-Yuk; Smith, David K.

    2016-01-01

    ABSTRACT The H9N2 influenza viruses that are enzootic in terrestrial poultry in China pose a persistent pandemic threat to humans. To investigate whether the continuous circulation and adaptation of these viruses in terrestrial poultry increased their infectivity to pigs, we conducted a serological survey in pig herds with H9N2 viruses selected from the aquatic avian gene pool (Y439 lineage) and the enzootic terrestrial poultry viruses (G1 and Y280 lineages). We also compared the infectivity and transmissibility of these viruses in pigs. It was found that more than 15% of the pigs sampled from 2010 to 2012 in southern China were seropositive to either G1 or Y280 lineage viruses, but none of the sera were positive to the H9 viruses from the Y439 lineage. Viruses of the G1 and Y280 lineages were able to infect experimental pigs, with detectable nasal shedding of the viruses and seroconversion, whereas viruses of the Y439 lineage did not cause a productive infection in pigs. Thus, adaptation and prevalence in terrestrial poultry could lead to interspecies transmission of H9N2 viruses from birds to pigs. Although H9N2 viruses do not appear to be continuously transmissible among pigs, repeated introductions of H9 viruses to pigs naturally increase the risk of generating mammalian-adapted or reassorted variants that are potentially infectious to humans. This study highlights the importance of monitoring the activity of H9N2 viruses in terrestrial poultry and pigs. IMPORTANCE H9N2 subtype of influenza viruses has repeatedly been introduced into mammalian hosts, including humans and pigs, so awareness of their activity and evolution is important for influenza pandemic preparedness. However, since H9N2 viruses usually cause mild or even asymptomatic infections in mammalian hosts, they may be overlooked in influenza surveillance. Here, we found that the H9N2 viruses established in terrestrial poultry had higher infectivity in pigs than those from aquatic birds, which

  15. Cross-reactivity between avian influenza A (H7N9) virus and divergent H7 subtypic- and heterosubtypic influenza A viruses

    PubMed Central

    Guo, Li; Wang, Dayan; Zhou, Hongli; Wu, Chao; Gao, Xin; Xiao, Yan; Ren, Lili; Paranhos-Baccalà, Gláucia; Shu, Yuelong; Jin, Qi; Wang, Jianwei

    2016-01-01

    The number of human avian H7N9 influenza infections has been increasing in China. Understanding their antigenic and serologic relationships is crucial for developing diagnostic tools and vaccines. Here, we evaluated the cross-reactivities and neutralizing activities among H7 subtype influenza viruses and between H7N9 and heterosubtype influenza A viruses. We found strong cross-reactivities between H7N9 and divergent H7 subtypic viruses, including H7N2, H7N3, and H7N7. Antisera against H7N2, H7N3, and H7N7 could also effectively neutralize two distinct H7N9 strains. Two-way cross-reactivities exist within group 2, including H3 and H4, whereas one-way cross-reactivities were found across other groups, including H1, H10, H9, and H13. Our data indicate that the hemaglutinins from divergent H7 subtypes may facilitate the development of vaccines for distinct H7N9 infections. Moreover, serologic diagnoses for H7N9 infections need to consider possible interference from the cross-reactivity of H7N9 with other subtype influenza viruses. PMID:26907865

  16. H1N1 Swine Influenza Viruses Differ from Avian Precursors by a Higher pH Optimum of Membrane Fusion

    PubMed Central

    Baumann, Jan; Kouassi, Nancy Mounogou; Foni, Emanuela; Klenk, Hans-Dieter

    2015-01-01

    ABSTRACT The H1N1 Eurasian avian-like swine (EAsw) influenza viruses originated from an avian H1N1 virus. To characterize potential changes in the membrane fusion activity of the hemagglutinin (HA) during avian-to-swine adaptation of the virus, we studied EAsw viruses isolated in the first years of their circulation in pigs and closely related contemporary H1N1 viruses of wild aquatic birds. Compared to the avian viruses, the swine viruses were less sensitive to neutralization by lysosomotropic agent NH4Cl in MDCK cells, had a higher pH optimum of hemolytic activity, and were less stable at acidic pH. Eight amino acid substitutions in the HA were found to separate the EAsw viruses from their putative avian precursor; four substitutions—T492S, N722D, R752K, and S1132F—were located in the structural regions of the HA2 subunit known to play a role in acid-induced conformational transition of the HA. We also studied low-pH-induced syncytium formation by cell-expressed HA proteins and found that the HAs of the 1918, 1957, 1968, and 2009 pandemic viruses required a lower pH for fusion induction than did the HA of a representative EAsw virus. Our data show that transmission of an avian H1N1 virus to pigs was accompanied by changes in conformational stability and fusion promotion activity of the HA. We conclude that distinctive host-determined fusion characteristics of the HA may represent a barrier for avian-to-swine and swine-to-human transmission of influenza viruses. IMPORTANCE Continuing cases of human infections with zoonotic influenza viruses highlight the necessity to understand which viral properties contribute to interspecies transmission. Efficient binding of the HA to cellular receptors in a new host species is known to be essential for the transmission. Less is known about required adaptive changes in the membrane fusion activity of the HA. Here we show that adaptation of an avian influenza virus to pigs in Europe in 1980s was accompanied by mutations in

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

    PubMed

    Jhung, Michael A; Nelson, Deborah I

    2015-02-01

    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.

  18. Structure and receptor binding of the hemagglutinin from a human H6N1 influenza virus.

    PubMed

    Tzarum, Netanel; de Vries, Robert P; Zhu, Xueyong; Yu, Wenli; McBride, Ryan; Paulson, James C; Wilson, Ian A

    2015-03-11

    Avian influenza viruses that cause infection and are transmissible in humans involve changes in the receptor binding site (RBS) of the viral hemagglutinin (HA) that alter receptor preference from α2-3-linked (avian-like) to α2-6-linked (human-like) sialosides. A human case of avian-origin H6N1 influenza virus was recently reported, but the molecular mechanisms contributing to it crossing the species barrier are unknown. We find that, although the H6 HA RBS contains D190V and G228S substitutions that potentially promote human receptor binding, recombinant H6 HA preferentially binds α2-3-linked sialosides, indicating no adaptation to human receptors. Crystal structures of H6 HA with avian and human receptor analogs reveal that H6 HA preferentially interacts with avian receptor analogs. This binding mechanism differs from other HA subtypes due to a unique combination of RBS residues, highlighting additional variation in HA-receptor interactions and the challenges in predicting which influenza strains and subtypes can infect humans and cause pandemics. PMID:25766295

  19. Genetic evolution of H5 highly pathogenic avian influenza virus in domestic poultry in Vietnam between 2011 and 2013.

    PubMed

    Lee, Eun-Kyoung; Kang, Hyun-Mi; Kim, Kwang-Il; Choi, Jun-Gu; To, Thanh Long; Nguyen, Tho Dang; Song, Byung-Min; Jeong, Jipseol; Choi, Kang-Seuk; Kim, Ji-Ye; Lee, Hee-Soo; Lee, Youn-Jeong; Kim, Jae-Hong

    2015-04-01

    In spite of highly pathogenic avian influenza H5N1 vaccination campaigns for domestic poultry, H5N1 viruses continue to circulate in Vietnam. To estimate the prevalence of avian influenza virus in Vietnam, surveillance was conducted between November 2011 and February 2013. Genetic analysis of 312 highly pathogenic avian influenza H5 viruses isolated from poultry in Vietnam was conducted and possible genetic relationships with strains from neighboring countries were investigated. As previously reported, phylogenetic analysis of the avian influenza virus revealed two H5N1 HPAI clades that were circulating in Vietnam. Clade 1.1, related to Cambodian strains, was predominant in the southern provinces, while clade 2.3.2.1 viruses were predominant in the northern and central provinces. Sequence analysis revealed evidence of active genetic evolution. In the gene constellation of clade 2.3.2.1, genotypes A, B, and B(II) existed during the 2011/2012 winter season. In June 2012, new genotype C emerged by reassortment between genotype A and genotype B(II), and this genotype was predominant in 2013 in the northern and central provinces. Interestingly, enzootic Vietnamese clade 2.3.2.1C H5 virus subsequently reassorted with N2, which originated from wild birds, to generate H5N2 highly pathogenic avian influenza, which was isolated from duck in the northeast region. This investigation indicated that H5N1 outbreaks persist in Vietnam and cause genetic reassortment with circulating viruses. It is necessary to strengthen active influenza surveillance to eradicate highly pathogenic avian influenza viruses and sever the link between highly pathogenic avian influenza and other circulating influenza viruses.

  20. Avian influenza surveillance in Central and West Africa, 2010-2014.

    PubMed

    Fuller, T L; Ducatez, M F; Njabo, K Y; Couacy-Hymann, E; Chasar, A; Aplogan, G L; Lao, S; Awoume, F; Téhou, A; Langeois, Q; Krauss, S; Smith, T B

    2015-07-01

    Avian influenza virus (AIV) is an important zoonotic pathogen, resulting in global human morbidity and mortality and substantial economic losses to the poultry industry. Poultry and wild birds have transmitted AIV to humans, most frequently subtypes H5 and H7, but also different strains and subtypes of H6, H9, and H10. Determining which birds are AIV reservoirs can help identify human populations that have a high risk of infection with these viruses due to occupational or recreational exposure to the reservoir species. To assess the prevalence of AIV in tropical birds, from 2010 to 2014, we sampled 40 099 birds at 32 sites in Central Africa (Cameroon, Central African Republic, Congo-Brazzaville, Gabon) and West Africa (Benin, Côte d'Ivoire, Togo). In Central Africa, detection rates by real-time RT-PCR were 16·6% in songbirds (eight passerine families, n = 1257), 16·4% in kingfishers (family Alcedinidae, n = 73), 8·2% in ducks (family Anatidae, n = 564), and 3·65% in chickens (family Phasianidae, n = 1042). Public health authorities should educate human cohorts that have high exposure to these bird populations about AIV and assess their adherence to biosecurity practices, including Cameroonian farmers who raise small backyard flocks.