Sample records for ah1n1 influenza virus

  1. Evolution and adaptation of the pandemic A/H1N1 2009 influenza virus

    Ducatez MF


    Full Text Available Mariette F Ducatez, Thomas P Fabrizio, Richard J WebbyDepartment of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USAAbstract: The emergence of the 2009 H1N1 pandemic influenza virus [A(H1N1pdm09] has provided the public health community with many challenges, but also the scientific community with an opportunity to monitor closely its evolution through the processes of drift and shift. To date, and despite having circulated in humans for nearly two years, little antigenic variation has been observed in the A(H1N1pdm09 viruses. However, as the A(H1N1pdm09 virus continues to circulate and the immunologic pressure within the human population increases, future antigenic change is almost a certainty. Several coinfections of A(H1N1pdm09 and seasonal A(H1N1 or A(H3N2 viruses have been observed, but no reassortant viruses have been described in humans, suggesting a lack of fitness of reassortant viruses or a lack of opportunities for interaction of different viral lineages. In contrast, multiple reassortment events have been detected in swine populations between A(H1N1 pdm09 and other endemic swine viruses. Somewhat surprisingly, many of the well characterized influenza virus virulence markers appear to have limited impact on the phenotype of the A(H1N1pdm09 viruses when they have been introduced into mutant viruses in laboratory settings. As such, it is unclear what the evolutionary path of the pandemic virus will be, but the monitoring of any changes in the circulating viruses will remain a global public and animal health priority.Keywords: influenza, pandemic, evolution, adaptation

  2. Antibody response of healthy children to pandemic A/H1N1/2009 influenza virus

    Esposito Susanna


    Full Text Available Abstract Background Little is known about the proportion of pediatric pandemic A/H1N1/2009 influenza cases who showed seroconversion, the magnitude of this seroconversion, or the factors that can affect the antibody level evoked by the pandemic A/H1N1/2009 influenza. Aims of this study were to analyse antibody responses and the factors associated with high antibody titres in a cohort of children with naturally acquired A/H1N1/2009 influenza infection confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR. Results Demographic, clinical and virologic data were collected from 69 otherwise healthy children with pandemic A/H1N1/2009 influenza (27 females, mean age ± SD: 5.01 ± 4.55 years. Their antibody levels against pandemic A/H1N1/2009 and seasonal A/H1N1 influenza viruses were evaluated by measuring hemagglutination-inhibiting antibodies using standard assays. Sixty-four patients (92.8% with pandemic A/H1N1/2009 influenza had A/H1N1/2009 antibody levels of ≥40, whereas only 28/69 (40.6% were seroprotected against seasonal A/H1N1 influenza virus. Those who were seroprotected against seasonal A/H1N1 virus were significantly older, significantly more often hospitalised, had a diagnosis of pneumonia significantly more frequently, and were significantly more often treated with oseltamivir than those who were not seroprotected (p Conclusions Otherwise healthy children seem to show seroprotective antibody titres after natural infection with pandemic A/H1N1/2009 influenza virus. The strength of the immune response seems to be related to the severity of the disease, but not to previous seasonal A/H1N1 influenza immunity.

  3. Transmission parameters of the A/H1N1 (2009) influenza virus pandemic: a review

    Boëlle, Pierre‐Yves; Ansart, Séverine; Cori, Anne; Valleron, Alain‐Jacques


    Please cite this paper as: Boëlle P‐Y et al. (2011) Transmission parameters of the A/H1N1 (2009) influenza virus pandemic: a review. Influenza and Other Respiratory Viruses 5(5), 306–316. Background  The new influenza virus A/H1N1 (2009), identified in mid‐2009, rapidly spread over the world. Estimating the transmissibility of this new virus was a public health priority. Methods  We reviewed all studies presenting estimates of the serial interval or generation time and the reproduction number of the A/H1N1 (2009) virus infection. Results  Thirteen studies documented the serial interval from household or close‐contact studies, with overall mean 3 days (95% CI: 2·4, 3·6); taking into account tertiary transmission reduced this estimate to 2·6 days. Model‐based estimates were more variable, from 1·9 to 6 days. Twenty‐four studies reported reproduction numbers for community‐based epidemics at the town or country level. The range was 1·2–3·1, with larger estimates reported at the beginning of the pandemic. Accounting for under‐reporting in the early period of the pandemic and limiting variation because of the choice of the generation time interval, the reproduction number was between 1·2 and 2·3 with median 1·5. Discussion  The serial interval of A/H1N1 (2009) flu was typically short, with mean value similar to the seasonal flu. The estimates of the reproduction number were more variable. Compared with past influenza pandemics, the median reproduction number was similar (1968) or slightly smaller (1889, 1918, 1957). PMID:21668690

  4. An outbreak of influenza A(H1N1)pdm09 virus in a primary school in Vietnam

    Duong, Tran Nhu; Tho, Nguyen Thi Thi; Hien, Nguyen Tran; Olowokure, Babatunde


    Background Despite school pupils being at greatest risk during the 2009 influenza pandemic there are limited data on outbreaks of influenza A(H1N1)pdm09 in primary schools in South-East Asia. This prospective cohort study describes an outbreak of influenza A(H1N1)pdm09 in a primary school in rural Vietnam. Findings In total 103 cases of influenza-like illness were found among the 407 pupils in the primary school. Ten of these were laboratory confirmed cases of influenza A(H1N1)pdm09 virus. Th...

  5. Oseltamivir-resistant influenza A(H1N1pdm09 virus in southern Brazil

    Camila Marx


    Full Text Available The neuraminidase (NA genes of A(H1N1pdm09 influenza virus isolates from 306 infected patients were analysed. The circulation of oseltamivir-resistant viruses in Brazil has not been reported previously. Clinical samples were collected in the state of Rio Grande do Sul (RS from 2009-2011 and two NA inhibitor-resistant mutants were identified, one in 2009 (H275Y and the other in 2011 (S247N. This study revealed a low prevalence of resistant viruses (0.8% with no spread of the resistant mutants throughout RS.

  6. Viral shedding in children infected by pandemic A/H1N1/2009 influenza virus

    Fossali Emilio; Taroni Francesca; Campanini Giulia; Scala Alessia; Baldanti Fausto; Daleno Cristina; Esposito Susanna; Pelucchi Claudio; Principi Nicola


    Abstract Background The aim of this study was to investigate viral shedding in otherwise healthy children with pandemic A/H1N1/2009 influenza in order to define how long children with pandemic A/H1N1/2009 influenza shed the virus, and also plan adequate measures to control the spread of the disease within households. Findings In 74 otherwise healthy children with pandemic A/H1N1/2009 influenza, nasopharyngeal swabs were taken for virus detection upon hospital admission and every two days unti...

  7. [Effect of Yinghua Pinggan granule against influenza A/H1N1 virus in vivo].

    Peng, Xue-qian; He, Yu; Zhou, Hui-fen; Zhang, Yu-yan; Yang, Jie-hong; Chen, Jun-kui; Lu, Yi-yu; Wan, Hai-tong


    To study the effect of Yinghua Pinggan granule (YHPG) against influenza A/H1N1 virus in vivo and on the immunologic function of infected mice. The intranasal influenza virus infection was adopted in ICR mouse to establish the influenza virus pneumonia model. At the 3rd and 7th day after the infection, the lung index and pathologic changes in lung tissues of mice were detected. Realtime PCR and flow cytometry were employed to observe the virus load in lung tissues and the levels of CD4+, CD8+, and CD4+/CD8+ in peripheral blood. The result showed that at the 3rd and 7th day after the infection, YHPG (15, 30 g x kg(-1)) can significant decrease in the lung index and virus load in lung tissues of mice infected with influenza virus, alleviate the pathologic changes in lung tissues, significantly increase the levels of CD4+ and CD4+/CD8+ ratio and reduce the levels of CD8+ in whole blood. This indicated that YHPG can inhibit the influenza virus replication, alleviate pulmonary damage and adjust the weak immunologic function of infected mice, with a certain therapeutic effect on mice infected by H1N1 virus in vivo. PMID:26975112

  8. Detection of influenza A(H1N1)v virus by real-time RT-PCR.

    Hollmann, B.; Wenzel, J. J.; Eis-hü binger, Am; Olschlä ger, S.; Huzly, D.; Drosten, C.; Panning, M.; Gu; nther, S.; Niller, H H; Becker, S.; Monazahian, M.; Matz, B.


    Influenza A(H1N1)v virus was first identified in April 2009. A novel real-time RT-PCR for influenza A(H1N1)v virus was set up ad hoc and validated following industry-standard criteria. The lower limit of detection of the assay was 384 copies of viral RNA per ml of viral transport medium (95% confidence interval: 273-876 RNA copies/ml). Specificity was 100% as assessed on a panel of reference samples including seasonal human influenza A virus H1N1 and H3N2, highly pathogenic avian influenza A ...

  9. Generation and Characterization of Recombinant Pandemic Influenza A(H1N1) Viruses Resistant to Neuraminidase Inhibitors

    Pizzorno, Andrés; Bouhy, Xavier; Abed, Yacine; Boivin, Guy


    Background. Neuraminidase inhibitors (NAIs) play a key role in the management of influenza epidemics and pandemics. Given the novel pandemic influenza A(H1N1) (pH1N1) virus and the restricted number of approved anti-influenza drugs, evaluation of potential drug-resistant variants is of high priority.

  10. [Advances in the structure and function of pandemic A/H1N1/2009 influenza virus HA protein].

    Zhang, Wen-Qiang; Song, Shao-Xia; Wang, Tong-Zhan


    Since March 2009, pandemic A/H1N1/2009 influenza virus has been spreading throughout many countries including China. The emerged virus caused great harm to human health and social economy. Hemagglutinin (HA) is the most important viral surface glycoprotein, mainly possessing three kinds of functions: (1) binding to host cell receptor, (2) triggering the fusion between viral envelop and target cell membrane, (3) stimulating the body to generate the neutralizing antibody. Advances in the structure, primary function, evolution and antigenicity of pandemic A/H1N1/2009 influenza virus HA protein are reviewed in this paper. PMID:22978172

  11. Seroprevalence of Influenza A(H1N1)pdm09 Virus Antibody, England, 2010 and 2011

    Hoschler, K; C. Thompson; Andrews, N.; Galiano, M; Pebody, R; Ellis, J.; Stanford, E; Baguelin, M.; Miller, E.; Zambon, M


    The intense influenza activity in England during the 2010-11 winter resulted from a combination of factors. Population-based seroepidemiology confirms that the third wave of influenza A(H1N1)pdm09 virus circulation was associated with a shift in age groups affected, with the highest rate of infection in young adults.

  12. Seroprevalence of influenza A(H1N1)pdm09 virus antibody, England, 2010 and 2011.

    Hoschler, Katja; Thompson, Catherine; Andrews, Nick; Galiano, Monica; Pebody, Richard; Ellis, Joanna; Stanford, Elaine; Baguelin, Marc; Miller, Elizabeth; Zambon, Maria


    The intense influenza activity in England during the 2010-11 winter resulted from a combination of factors. Population-based seroepidemiology confirms that the third wave of influenza A(H1N1)pdm09 virus circulation was associated with a shift in age groups affected, with the highest rate of infection in young adults. PMID:23092684

  13. Natural A(H1N1)pdm09 influenza virus infection case in a pet ferret in Taiwan.

    Lin, Hui-Ting; Wang, Ching-Ho; Wu, Wen-Ling; Chi, Chau-Hwa; Wang, Lih Chiann


    Ferrets have demonstrated high susceptibility to the influenza virus. This study discusses a natural 2009 pandemic influenza A (H1N1) (A(H1N1)pdm09) virus infection in a pet ferret (Mustela putorius furo) identified in Taiwan in 2013. The ferret was in close contact with family members who had recently experienced an influenza-like illness (ILI). The ferret nasal swab showed positive results for influenza A virus using one-step RT-PCR. The virus was isolated and the phylogenetic analysis indicated that all of the eight segmented genes were closely related to the human A(H1N1)pdm09 virus linage isolated in Taiwan. This study may provide a perspective view on natural influenza A virus transmission from the local human population into pet ferrets. PMID:25597188

  14. Detection of influenza A(H1N1)v virus by real-time RT-PCR.

    Panning, M; Eickmann, M; Landt, O; Monazahian, M; Olschläger, S; Baumgarte, S; Reischl, U; Wenzel, J J; Niller, H H; Günther, S; Hollmann, B; Huzly, D; Drexler, J F; Helmer, A; Becker, S; Matz, B; Eis-Hübinger, Am; Drosten, C


    Influenza A(H1N1)v virus was first identified in April 2009. A novel real-time RT-PCR for influenza A(H1N1)v virus was set up ad hoc and validated following industry-standard criteria. The lower limit of detection of the assay was 384 copies of viral RNA per ml of viral transport medium (95% confidence interval: 273-876 RNA copies/ml). Specificity was 100% as assessed on a panel of reference samples including seasonal human influenza A virus H1N1 and H3N2, highly pathogenic avian influenza A virus H5N1 and porcine influenza A virus H1N1, H1N2 and H3N2 samples. The real-time RT-PCR assay for the influenza A matrix gene recommended in 2007 by the World Health Organization was modified to work under the same reaction conditions as the influenza A(H1N1)v virus-specific test. Both assays were equally sensitive. Clinical applicability of both assays was demonstrated by screening of almost 2,000 suspected influenza (H1N1)v specimens, which included samples from the first cases of pandemic H1N1 influenza imported to Germany. Measuring influenza A(H1N1)v virus concentrations in 144 laboratory-confirmed samples yielded a median of 4.6 log RNA copies/ml. The new methodology proved its principle and might assist public health laboratories in the upcoming influenza pandemic. PMID:19758541

  15. Detection of Extensive Cross-Neutralization between Pandemic and Seasonal A/H1N1 Influenza Viruses Using a Pseudotype Neutralization Assay

    Labrosse, Béatrice; Tourdjman, Mathieu; Porcher, Raphaël; LeGoff, Jérôme; de Lamballerie, Xavier; Simon, François; Molina, Jean-Michel; Clavel, François


    Background Cross-immunity between seasonal and pandemic A/H1N1 influenza viruses remains uncertain. In particular, the extent that previous infection or vaccination by seasonal A/H1N1 viruses can elicit protective immunity against pandemic A/H1N1 is unclear. Methodology/Principal Findings Neutralizing titers against seasonal A/H1N1 (A/Brisbane/59/2007) and against pandemic A/H1N1 (A/California/04/2009) were measured using an HIV-1-based pseudovirus neutralization assay. Using this highly sens...

  16. Molecular epidemiology of influenza A(H1N1pdm09 viruses from Pakistan in 2009-2010.

    Uzma Bashir Aamir

    Full Text Available BACKGROUND: In early 2009, a novel influenza A(H1N1 virus that emerged in Mexico and United States rapidly disseminated worldwide. The spread of this virus caused considerable morbidity with over 18000 recorded deaths. The new virus was found to be a reassortant containing gene segments from human, avian and swine influenza viruses. METHODS/RESULTS: The first case of human infection with A(H1N1pdm09 in Pakistan was detected on 18(th June 2009. Since then, 262 laboratory-confirmed cases have been detected during various outbreaks with 29 deaths (as of 31(st August 2010. The peak of the epidemic was observed in December with over 51% of total respiratory cases positive for influenza. Representative isolates from Pakistan viruses were sequenced and analyzed antigenically. Sequence analysis of genes coding for surface glycoproteins HA and NA showed high degree of high levels of sequence identity with corresponding genes of regional viruses circulating South East Asia. All tested viruses were sensitive to Oseltamivir in the Neuraminidase Inhibition assays. CONCLUSIONS: Influenza A(H1N1pdm09 viruses from Pakistan form a homogenous group of viruses. Their HA genes belong to clade 7 and show antigenic profile similar to the vaccine strain A/California/07/2009. These isolates do not show any amino acid changes indicative of high pathogenicity and virulence. It is imperative to continue monitoring of these viruses for identification of potential variants of high virulence or drug resistance.

  17. Viral shedding in children infected by pandemic A/H1N1/2009 influenza virus

    Fossali Emilio


    Full Text Available Abstract Background The aim of this study was to investigate viral shedding in otherwise healthy children with pandemic A/H1N1/2009 influenza in order to define how long children with pandemic A/H1N1/2009 influenza shed the virus, and also plan adequate measures to control the spread of the disease within households. Findings In 74 otherwise healthy children with pandemic A/H1N1/2009 influenza, nasopharyngeal swabs were taken for virus detection upon hospital admission and every two days until negative. The nasopharyngeal swabs of all of the children were positive for pandemic A/H1N1/2009 influenza virus in the first three days after the onset of infection, and only 21.6% and 13.5% remained positive after respectively 11 and 15 days. No child was positive after more than 15 days. Viral load also decreased over time, and was not associated with patient age or the risk of pneumonia. Those who shed the virus for ≥ 9 days were not at any increased risk of suffering from more severe disease in comparison with those who shed the virus for a shorter time, but their households experienced a significantly higher number of influenza-like illness during the two weeks after the onset of the initial disease (72.3% vs 41.4%; p Conclusions Regardless of their age, healthy children can shed pandemic A/H1N1/2009 influenza virus for up to two weeks after illness onset, and the households of the children who shed the virus for ≥ 9 days suffered a higher number of influenza-like illness in the two weeks following the onset of the first disease. This could suggest that when a completely unknown influenza virus is circulating, isolation period of infected children has to be longer than the 7 days recommended for the infections due to seasonal influenza viruses.

  18. Productive infection of human skeletal muscle cells by pandemic and seasonal influenza A(H1N1 viruses.

    Marion Desdouits

    Full Text Available Besides the classical respiratory and systemic symptoms, unusual complications of influenza A infection in humans involve the skeletal muscles. Numerous cases of acute myopathy and/or rhabdomyolysis have been reported, particularly following the outbreak of pandemic influenza A(H1N1 in 2009. The pathogenesis of these influenza-associated myopathies (IAM remains unkown, although the direct infection of muscle cells is suspected. Here, we studied the susceptibility of cultured human primary muscle cells to a 2009 pandemic and a 2008 seasonal influenza A(H1N1 isolate. Using cells from different donors, we found that differentiated muscle cells (i. e. myotubes were highly susceptible to infection by both influenza A(H1N1 isolates, whereas undifferentiated cells (i. e. myoblasts were partially resistant. The receptors for influenza viruses, α2-6 and α2-3 linked sialic acids, were detected on the surface of myotubes and myoblasts. Time line of viral nucleoprotein (NP expression and nuclear export showed that the first steps of the viral replication cycle could take place in muscle cells. Infected myotubes and myoblasts exhibited budding virions and nuclear inclusions as observed by transmission electron microscopy and correlative light and electron microscopy. Myotubes, but not myoblasts, yielded infectious virus progeny that could further infect naive muscle cells after proteolytic treatment. Infection led to a cytopathic effect with the lysis of muscle cells, as characterized by the release of lactate dehydrogenase. The secretion of proinflammatory cytokines by muscle cells was not affected following infection. Our results are compatible with the hypothesis of a direct muscle infection causing rhabdomyolysis in IAM patients.

  19. Antibody response of healthy children to pandemic A/H1N1/2009 influenza virus

    Esposito Susanna; Daleno Cristina; Tagliabue Claudia; Scala Alessia; Picciolli Irene; Taroni Francesca; Galeone Carlotta; Baldanti Fausto; Principi Nicola


    Abstract Background Little is known about the proportion of pediatric pandemic A/H1N1/2009 influenza cases who showed seroconversion, the magnitude of this seroconversion, or the factors that can affect the antibody level evoked by the pandemic A/H1N1/2009 influenza. Aims of this study were to analyse antibody responses and the factors associated with high antibody titres in a cohort of children with naturally acquired A/H1N1/2009 influenza infection confirmed by reverse-transcriptase polymer...

  20. Los virus Influenza y la nueva pandemia A/H1N1

    Miguel Talledo; Kattya Zumaeta


    Los virus Influenza pertenecen a la familia Orthomyxoviridae, virus con genoma RNA de sentido negativo segmentado. Los virus influenza tipo A infectan a humanos y otros organismos, y son los agentes causantes de influenza en humanos. Resaltan entre sus principales proteínas la Hemaglutinina y la Neuraminidasa, que son utilizadas en la clasificación de los miembros de este grupo. Estos virus mutan continuamente, exhibiendo patrones muy estudiados, como el cambio y la deriva antigénica, siendo ...

  1. Top leads for swine influenza A/H1N1 virus revealed by steered molecular dynamics approach.

    Mai, Binh Khanh; Viet, Man Hoang; Li, Mai Suan


    Since March 2009, the rapid spread of infection during the recent A/H1N1 swine flu pandemic has raised concerns of a far more dangerous outcome should this virus become resistant to current drug therapies. Currently oseltamivir (tamiflu) is intensively used for the treatment of influenza and is reported effective for 2009 A/H1N1 virus. However, as this virus is evolving fast, some drug-resistant strains are emerging. Therefore, it is critical to seek alternative treatments and identify roots of the drug resistance. In this paper, we use the steered molecular dynamics (SMD) approach to estimate the binding affinity of ligands to the glycoprotein neuraminidase. Our idea is based on the hypothesis that the larger is the force needed to unbind a ligand from a receptor the higher its binding affinity. Using all-atom models with Gromos force field 43a1 and explicit water, we have studied the binding ability of 32 ligands to glycoprotein neuraminidase from swine flu virus A/H1N1. The electrostatic interaction is shown to play a more important role in binding affinity than the van der Waals one. We have found that four ligands 141562, 5069, 46080, and 117079 from the NSC set are the most promising candidates to cope with this virus, while peramivir, oseltamivir, and zanamivir are ranked 8, 11, and 20. The observation that these four ligands are better than existing commercial drugs has been also confirmed by our results on the binding free energies obtained by the molecular mechanics-Poisson-Boltzmann surface area (MM-PBSA) method. Our prediction may be useful for the therapeutic application. PMID:21090736

  2. Enhanced Pneumonia With Pandemic 2009 A/H1N1 Swine Influenza Virus in Pigs

    Introduction. Swine influenza A viruses (SIV) in the major swine producing regions of North America consist of multiple subtypes of endemic H1N1, H1N2, and H3N2 derived from swine, avian and human influenza viruses with a triple reassortant internal gene (TRIG) constellation (1). Genetic drift and r...

  3. Effect of human rhinovirus infection in pediatric patients with influenza-like illness on the 2009 pandemic influenza A(H1N1) virus

    Sun Yu; Zhu Ru'nan; Zhao Linqing; Deng Jie; Wang Fang; Ding Yaxin; Yuan Yi


    Background Some research groups have hypothesized that human rhinoviruses (HRVs) delayed the circulation of the 2009 pandemic influenza A(H1N1) virus (A(H1N1)pdm09) at the beginning of Autumn 2009 in France.This study aimed to evaluate the relationship between HRV and A(H1N1)pdm09 in pediatric patients with influenza-like illness in Beijing,China.Methods A systematic analysis to detect A(H1N1)pdm09 and seasonal influenza A virus (FLU A) was performed on 4 349 clinical samples from pediatric patients with influenza-like illness during the period June 1,2009 to February 28,2010,while a one-step real-time RT-PCR (rRT-PCR) assay was used to detect HRV in 1 146 clinical specimens selected from those 4 349 specimens.Results During the survey period,only one wave of A(H1N1)pdm09 was observed.The percentage of positive cases for A(H1N1)pdm09 increased sharply in September with a peak in November 2009 and then declined in February 2010.Data on the monthly distribution of HRVs indicated that more HRV-positive samples were detected in September (2.2%) and October (3.3%),revealing that the peak of HRV infection in 2009 was similar to that of other years.Among the 1 146 specimens examined for HRVs,21 (1.8%) were HRV-positive,which was significantly lower than that reported previously in Beijing (15.4% to 19.2%) (P <0.01).Overall,6 samples were positive for both A(H1N1)pdm09 and HRV,which represented a positive relative frequency of 1.60% and 2.08% HRV,considering the A(H1N1)pdm09-positive and-negative specimens,respectively.The odds ratio was 0.87 (95% CI 0.32; 2.44,P=0.80).Conclusions HRVs and A (H1N1)pdm09 co-circulated in this Chinese population during September and October 2009,and the HRV epidemic in 2009 did not affect A(H1N1)pdm09 infection rates in Beijing,China as suggested by other studies.However,the presence of A(H1N1)pdm09 might explain the unexpected reduction in the percentage of HRV positive cases during the period studied.

  4. Los virus Influenza y la nueva pandemia A/H1N1

    Miguel Talledo


    Full Text Available Los virus Influenza pertenecen a la familia Orthomyxoviridae, virus con genoma RNA de sentido negativo segmentado. Los virus influenza tipo A infectan a humanos y otros organismos, y son los agentes causantes de influenza en humanos. Resaltan entre sus principales proteínas la Hemaglutinina y la Neuraminidasa, que son utilizadas en la clasificación de los miembros de este grupo. Estos virus mutan continuamente, exhibiendo patrones muy estudiados, como el cambio y la deriva antigénica, siendo uno de los principales eventos de recombinación el reordenamiento. Todos los subtipos se encuentran en aves acuáticas silvestres, aunque se han encontrado otros hospederos, como equinos, visones, ballenas, focas, cerdos, gallinas y pavos, entre otros. Tanto las aves salvajes, las aves domésticas y el cerdo juegan un rol fundamental en la adaptación progresiva del virus al hospedero humano. Aunque los subtipos H2N2 y H3N2 han sido muy comunes, el subtipo H1N1 ha reemergido con mutaciones que le han permitido alcanzar el estado de pandemia en 2009. Este nuevo virus surge de un virus generado por triple reordenamiento con el virus humano, porcino norteamericano y aviar, conteniendo a su vez segmentos génicos de virus influenza porcina euroasiática. Esto ha hecho que el virus presente una enfermedad humana moderada y solamente severa y hasta letal en casos de individuos con condiciones médicas previas. A nivel mundial ha causado más de 134,510 casos y en el Perú alcanza cerca de 3,700 casos. El estado actual indica que la pandemia está por llegar a su pico máximo en el Perú, debido a la alta morbilidad del virus coincidente con la estación más fría del año. Es importante contener al máximo la dispersión del virus, ya que cuanto mayor sea el número de personas que infecte, el mismo estará sometido a un mayor número de eventos de recombinación genética por reordenamiento con virus influenza humanos previos y esto puede condicionar a la

  5. The association between serum biomarkers and disease outcome in influenza A(H1N1)pdm09 virus infection

    Davey, Richard T; Lynfield, Ruth; Dwyer, Dominic E; Losso, Marcello H; Cozzi-Lepri, Alessandro; Wentworth, Deborah; Lane, H Clifford; Dewar, Robin; Rupert, Adam; Metcalf, Julia A; Pett, Sarah L; Uyeki, Timothy M; Bruguera, Jose Maria; Angus, Brian; Cummins, Nathan; Lundgren, Jens; Neaton, James D


    Prospective studies establishing the temporal relationship between the degree of inflammation and human influenza disease progression are scarce. To assess predictors of disease progression among patients with influenza A(H1N1)pdm09 infection, 25 inflammatory biomarkers measured at enrollment were...

  6. Influenza A/H1N1/2009 virus - experience of the clinical microbiology laboratory of the “L. Sacco” University Hospital in Milan

    Lisa Lucia Chenal


    Full Text Available In the spring of 2009, a new variant of influenza A/H1N1 virus that had never been isolated before, was identified. From April 27 to December 31, 2009 the respiratory samples of 974 patients, obtained from suspected cases of pandemic influenza A virus infection, were analyzed at the Clinical Microbiology Laboratory of the “L. Sacco” University Hospital in Milan. The diagnosis of influenza A/H1N1 infection was performed initially through the use of different molecular biological methods: Seeplex® RV12 ACE Detection (Seegene, NUCLISENS® EASYQ® INFLUENZA A/B (bioMérieux, Influenza A/B Q-PCR Alert (Nanogen running in parallel with rRT-PCR (CDC to confirm the positivity to the new influenza virus, then was used a single specific test, Fast set H1N1v (Arrow Diagnostics. Retrospective study of data showed that 293 (30.1% patients were positive for the new strain of influenza A/H1N1 virus and 8 (0.8% for influenza A other than H1N1 virus.The distribution of influenza A/H1N1 cases showed two peaks, one on July (62.9% and the other one on October (36%, moreover we observed that 155 patients (53% out of 293 positive for influenza A/H1N1 virus aged under 20 years old. The first positivity peak was found in travelers and the second one, occurred 2-3 months prior to the classic seasonal epidemic influenza, was attributed to autochthonous cases , by which the virus had spread worldwide. The highest proportion of cases were among subjects aged from 0 to 20 years and, over this age the positivity rate decreased proportionally with increasing age, in agreement with data reported in other countries.

  7. Point of care strategy for rapid diagnosis of novel A/H1N1 influenza virus.

    Antoine Nougairede

    Full Text Available Within months of the emergence of the novel A/H1N1 pandemic influenza virus (nA/H1N1v, systematic screening for the surveillance of the pandemic was abandoned in France and in some other countries. At the end of June 2009, we implemented, for the public hospitals of Marseille, a Point Of Care (POC strategy for rapid diagnosis of the novel A/H1N1 influenza virus, in order to maintain local surveillance and to evaluate locally the kinetics of the pandemic.Two POC laboratories, located in strategic places, were organized to receive and test samples 24 h/24. POC strategy consisted of receiving and processing naso-pharyngeal specimens in preparation for the rapid influenza diagnostic test (RIDT and real-time RT-PCR assay (rtRT-PCR. This strategy had the theoretical capacity of processing up to 36 samples per 24 h. When the flow of samples was too high, the rtRT-PCR test was abandoned in the POC laboratories and transferred to the core virology laboratory. Confirmatory diagnosis was performed in the core virology laboratory twice a day using two distinct rtRT-PCR techniques that detect either influenza A virus or nA/N1N1v. Over a period of three months, 1974 samples were received in the POC laboratories, of which 111 were positive for nA/H1N1v. Specificity and sensitivity of RIDT were 100%, and 57.7% respectively. Positive results obtained using RIDT were transmitted to clinical practitioners in less than 2 hours. POC processed rtRT-PCR results were available within 7 hours, and rtRT-PCR confirmation within 24 hours.The POC strategy is of benefit, in all cases (with or without rtRT-PCR assay, because it provides continuous reception/processing of samples and reduction of the time to provide consolidated results to the clinical practitioners. We believe that implementation of the POC strategy for the largest number of suspect cases may improve the quality of patient care and our knowledge of the epidemiology of the pandemic.

  8. Continued emergence and changing epidemiology of oseltamivir-resistant influenza A(H1N1)2009 virus, United Kingdom, winter 2010/11.

    Lackenby, A; Moran Gilad, J; Pebody, R; Miah, S; Calatayud, L; Bolotin, S; Vipond, I; Muir, P; Guiver, M; McMenamin, J; Reynolds, A; Moore, C; Gunson, R; Thompson, C; Galiano, M; Bermingham, A; Ellis, J; Zambon, M


    During the winter period 2010/11 27 epidemiologically unlinked, confirmed cases of oseltamivir-resistant influenza A(H1N1)2009 virus infection have been detected in multiple, geographically dispersed settings. Three of these cases were in community settings, with no known exposure to oseltamivir. This suggests possible onward transmission of resistant strains and could be an indication of a possibility of changing epidemiology of oseltamivir-resistant influenza A(H1N1)2009 virus. PMID:21315056

  9. Outcomes of influenza A(H1N1)pdm09 virus infection

    Lynfield, Ruth; Davey, Richard; Dwyer, Dominic E;


    initiated: FLU 002 in outpatients and FLU 003 in hospitalized patients. METHODS AND FINDINGS: Between October 2009 and December 2012, adults with influenza-like illness (ILI) were enrolled; outpatients were followed for 14 days and inpatients for 60 days. Disease progression was defined as hospitalization...... and/or death for outpatients, and hospitalization for >28 days, transfer to intensive care unit (ICU) if enrolled from general ward, and/or death for inpatients. Infection was confirmed by RT-PCR. 590 FLU 002 and 392 FLU 003 patients with influenza A (H1N1)pdm09 were enrolled from 81 sites in 17...... data reinforce the need for international trials of novel treatment strategies for influenza infection and serve as a reminder of the need to monitor the severity of seasonal and pandemic influenza epidemics globally. TRIAL REGISTRATION: Identifiers: FLU 002--NCT01056354, FLU 003...

  10. PD-L1 Expression Induced by the 2009 Pandemic Influenza A(H1N1 Virus Impairs the Human T Cell Response

    Nuriban Valero-Pacheco


    Full Text Available PD-L1 expression plays a critical role in the impairment of T cell responses during chronic infections; however, the expression of PD-L1 on T cells during acute viral infections, particularly during the pandemic influenza virus (A(H1N1pdm09, and its effects on the T cell response have not been widely explored. We found that A(H1N1pdm09 virus induced PD-L1 expression on human dendritic cells (DCs and T cells, as well as PD-1 expression on T cells. PD-L1 expression impaired the T cell response against A(H1N1pdm09 by promoting CD8+ T cell death and reducing cytokine production. Furthermore, we found increased PD-L1 expression on DCs and T cells from influenza-infected patients from the first and second 2009 pandemic waves in Mexico City. PD-L1 expression on CD8+ T cells correlated inversely with T cell proportions in patients infected with A(H1N1pdm09. Therefore, PD-L1 expression on DCs and T cells could be associated with an impaired T cell response during acute infection with A(H1N1pdm09 virus.

  11. Whole genome characterization of human influenza A(H1N1)pdm09 viruses isolated from Kenya during the 2009 pandemic.

    Gachara, George; Symekher, Samuel; Otieno, Michael; Magana, Japheth; Opot, Benjamin; Bulimo, Wallace


    An influenza pandemic caused by a novel influenza virus A(H1N1)pdm09 spread worldwide in 2009 and is estimated to have caused between 151,700 and 575,400 deaths globally. While whole genome data on new virus enables a deeper insight in the pathogenesis, epidemiology, and drug sensitivities of the circulating viruses, there are relatively limited complete genetic sequences available for this virus from African countries. We describe herein the full genome analysis of influenza A(H1N1)pdm09 viruses isolated in Kenya between June 2009 and August 2010. A total of 40 influenza A(H1N1)pdm09 viruses isolated during the pandemic were selected. The segments from each isolate were amplified and directly sequenced. The resulting sequences of individual gene segments were concatenated and used for subsequent analysis. These were used to infer phylogenetic relationships and also to reconstruct the time of most recent ancestor, time of introduction into the country, rates of substitution and to estimate a time-resolved phylogeny. The Kenyan complete genome sequences clustered with globally distributed clade 2 and clade 7 sequences but local clade 2 viruses did not circulate beyond the introductory foci while clade 7 viruses disseminated country wide. The time of the most recent common ancestor was estimated between April and June 2009, and distinct clusters circulated during the pandemic. The complete genome had an estimated rate of nucleotide substitution of 4.9×10(-3) substitutions/site/year and greater diversity in surface expressed proteins was observed. We show that two clades of influenza A(H1N1)pdm09 virus were introduced into Kenya from the UK and the pandemic was sustained as a result of importations. Several closely related but distinct clusters co-circulated locally during the peak pandemic phase but only one cluster dominated in the late phase of the pandemic suggesting that it possessed greater adaptability. PMID:26921801

  12. Antigenic and genomic characterization of human influenza A and B viruses circulating in Argentina after the introduction of influenza A(H1N1)pdm09.

    Russo, Mara L; Pontoriero, Andrea V; Benedetti, Estefania; Czech, Andrea; Avaro, Martin; Periolo, Natalia; Campos, Ana M; Savy, Vilma L; Baumeister, Elsa G


    This study was conducted as part of the Argentinean Influenza and other Respiratory Viruses Surveillance Network, in the context of the Global Influenza Surveillance carried out by the World Health Organization (WHO). The objective was to study the activity and the antigenic and genomic characteristics of circulating viruses for three consecutive seasons (2010, 2011 and 2012) in order to investigate the emergence of influenza viral variants. During the study period, influenza virus circulation was detected from January to December. Influenza A and B, and all current subtypes of human influenza viruses, were present each year. Throughout the 2010 post-pandemic season, influenza A(H1N1)pdm09, unexpectedly, almost disappeared. The haemagglutinin (HA) of the A(H1N1)pdm09 viruses studied were segregated in a different genetic group to those identified during the 2009 pandemic, although they were still antigenically closely related to the vaccine strain A/California/07/2009. Influenza A(H3N2) viruses were the predominant strains circulating during the 2011 season, accounting for nearly 76 % of influenza viruses identified. That year, all HA sequences of the A(H3N2) viruses tested fell into the A/Victoria/208/2009 genetic clade, but remained antigenically related to A/Perth/16/2009 (reference vaccine recommended for this three-year period). A(H3N2) viruses isolated in 2012 were antigenically closely related to A/Victoria/361/2011, recommended by the WHO as the H3 component for the 2013 Southern Hemisphere formulation. B viruses belonging to the B/Victoria lineage circulated in 2010. A mixed circulation of viral variants of both B/Victoria and B/Yamagata lineages was detected in 2012, with the former being predominant. A(H1N1)pdm09 viruses remained antigenically closely related to the vaccine virus A/California/7/2009; A(H3N2) viruses continually evolved into new antigenic clusters and both B lineages, B/Victoria/2/87-like and B/Yamagata/16/88-like viruses, were observed

  13. Molecular epidemiology of A/H3N2 and A/H1N1 influenza virus during a single epidemic season in the United States.

    Martha I Nelson

    Full Text Available To determine the spatial and temporal dynamics of influenza A virus during a single epidemic, we examined whole-genome sequences of 284 A/H1N1 and 69 A/H3N2 viruses collected across the continental United States during the 2006-2007 influenza season, representing the largest study of its kind undertaken to date. A phylogenetic analysis revealed that multiple clades of both A/H1N1 and A/H3N2 entered and co-circulated in the United States during this season, even in localities that are distant from major metropolitan areas, and with no clear pattern of spatial spread. In addition, co-circulating clades of the same subtype exchanged genome segments through reassortment, producing both a minor clade of A/H3N2 viruses that appears to have re-acquired sensitivity to the adamantane class of antiviral drugs, as well as a likely antigenically distinct A/H1N1 clade that became globally dominant following this season. Overall, the co-circulation of multiple viral clades during the 2006-2007 epidemic season revealed patterns of spatial spread that are far more complex than observed previously, and suggests a major role for both migration and reassortment in shaping the epidemiological dynamics of human influenza A virus.

  14. Sales of oseltamivir in Norway prior to the emergence of oseltamivir resistant influenza A(H1N1 viruses in 2007–08

    Hungnes Olav


    Full Text Available Abstract Background An unprecedented high proportion of oseltamivir resistant influenza A(H1N1 viruses emerged in the 2007–08 influenza season. In Norway, two thirds of all tested A(H1N1 viruses were resistant to the antiviral drug. In order to see if this emergence could be explained by a drug induced selection pressure, we analysed data on the sales of oseltamivir in Norway for the years 2002–07. Methods We used data from two sources; the Norwegian Drug Wholesales Statistics Database and the Norwegian Prescription Database (NorPD, for the years 2002–2007. We calculated courses sold of oseltamivir (Tamiflu® per 1000 inhabitants per year. Results Our data showed that, except for the years 2005 and 2006, sales of oseltamivir were low in Norway; courses sold per 1000 inhabitants varied between 0.17–1.64. The higher sales in 2005 and 2006 we believe were caused by private stockpiling in fear of a pandemic, and do not represent actual usage. Conclusion A drug induced selection pressure was probably not the cause of the emergence of oseltamivir resistant influenza A(H1N1 viruses in 2007–08 in Norway.

  15. Sequence-based identification and characterization of nosocomial influenza A(H1N1)pdm09 virus infections

    Jonges, M.; Rahamat-Langendoen, J.; Meijer, A.; Niesters, H. G.; Koopmans, M.


    Background: Highly transmissible viruses such as influenza are a potential source of nosocomial infections and thereby cause increased patient morbidity and mortality. Aim: To assess whether influenza virus sequence data can be used to link nosocomial influenza transmission between individuals. Meth

  16. Evidence of person-to-person transmission of oseltamivir-resistant pandemic influenza A(H1N1) 2009 virus in a hematology unit.

    Moore, Catherine; Galiano, Monica; Lackenby, Angie; Abdelrahman, Tamer; Barnes, Rosemary; Evans, Meirion R; Fegan, Christopher; Froude, Susannah; Hastings, Mark; Knapper, Steven; Litt, Emma; Price, Nicola; Salmon, Roland; Temple, Mark; Davies, Eleri


    We describe the first confirmed person-to-person transmission of oseltamivir-resistant pandemic influenza A(H1N1) 2009 virus that occurred in a hematology unit in the United Kingdom. Eleven cases of (H1N1) 2009 virus infection were identified, of which, ten were related as shown by sequence analysis of the hemagglutinin and neuraminidase genes. H275Y analysis demonstrated that 8 of 10 case patients had oseltamivir-resistant virus, with 4 of 8 case patients infected by direct transmission of resistant virus. Zanamivir should be considered as first-line therapy for influenza in patients with lymphopenic hematological conditions and uptake of influenza vaccination encouraged to further reduce the number of susceptible individuals. PMID:21148492

  17. Comparison of Immune Response by Virus Infection and Vaccination to 2009 Pandemic Influenza A/H1N1 in Children

    Kang, Eun Kyeong; Lim, Jung Sub; Lee, Jun Ah; KIM, DONG HO


    We aimed to compare the immune response induced by natural infection with 2009 pandemic influenza A/H1N1 (pH1N1) virus and by monovalent pH1N1 vaccination in children and adolescents. This cross-sectional clinical study was conducted at 3 hospitals in Korea from February to May 2010. A total of 266 healthy subjects aged from 6 months to 18 yr were tested for the presence of the antibody against pH1N1 using hemagglutination inhibition (HI) test. Information about pH1N1 vaccination and laborato...

  18. Comparison of shedding characteristics of seasonal influenza virus (subtypes and influenza A(H1N1pdm09; Germany, 2007-2011.

    Thorsten Suess

    Full Text Available BACKGROUND: Influenza viral shedding studies provide fundamental information for preventive strategies and modelling exercises. We conducted a prospective household study to investigate viral shedding in seasonal and pandemic influenza between 2007 and 2011 in Berlin and Munich, Germany. METHODS: Study physicians recruited index patients and their household members. Serial nasal specimens were obtained from all household members over at least eight days and tested quantitatively by qRT-PCR for the influenza virus (subtype of the index patient. A subset of samples was also tested by viral culture. Symptoms were recorded daily. RESULTS: We recruited 122 index patients and 320 household contacts, of which 67 became secondary household cases. Among all 189 influenza cases, 12 were infected with seasonal/prepandemic influenza A(H1N1, 19 with A(H3N2, 60 with influenza B, and 98 with A(H1N1pdm09. Nine (14% of 65 non-vaccinated secondary cases were asymptomatic/subclinical (0 (0% of 21 children, 9 (21% of 44 adults; p = 0.03. Viral load among patients with influenza-like illness (ILI peaked on illness days 1, 2 or 3 for all (subtypes and declined steadily until days 7-9. Clinical symptom scores roughly paralleled viral shedding dynamics. On the first day prior to symptom onset 30% (12/40 of specimens were positive. Viral load in 6 asymptomatic/subclinical patients was similar to that in ILI-patients. Duration of infectiousness as measured by viral culture lasted approximately until illness days 4-6. Viral load did not seem to be influenced by antiviral therapy, age or vaccination status. CONCLUSION: Asymptomatic/subclinical infections occur infrequently, but may be associated with substantial amounts of viral shedding. Presymptomatic shedding may arise in one third of cases, and shedding characteristics appear to be independent of (seasonal or pandemic (subtype, age, antiviral therapy or vaccination; however the power to find moderate differences

  19. Punctuated evolution of influenza virus neuraminidase (A/H1N1) under opposing migration and vaccination pressures.

    Phillips, J C


    Influenza virus contains two highly variable envelope glycoproteins, hemagglutinin (HA) and neuraminidase (NA). The structure and properties of HA, which is responsible for binding the virus to the cell that is being infected, change significantly when the virus is transmitted from avian or swine species to humans. Here we focus first on the simpler problem of the much smaller human individual evolutionary amino acid mutational changes in NA, which cleaves sialic acid groups and is required for influenza virus replication. Our thermodynamic panorama shows that very small amino acid changes can be monitored very accurately across many historic (1945-2011) Uniprot and NCBI strains using hydropathicity scales to quantify the roughness of water film packages. Quantitative sequential analysis is most effective with the fractal differential hydropathicity scale based on protein self-organized criticality (SOC). Our analysis shows that large-scale vaccination programs have been responsible for a very large convergent reduction in common influenza severity in the last century. Hydropathic analysis is capable of interpreting and even predicting trends of functional changes in mutation prolific viruses directly from amino acid sequences alone. An engineered strain of NA1 is described which could well be significantly less virulent than current circulating strains. PMID:25143953

  20. Punctuated Evolution of Influenza Virus Neuraminidase (A/H1N1 under Opposing Migration and Vaccination Pressures

    J. C. Phillips


    Full Text Available Influenza virus contains two highly variable envelope glycoproteins, hemagglutinin (HA and neuraminidase (NA. The structure and properties of HA, which is responsible for binding the virus to the cell that is being infected, change significantly when the virus is transmitted from avian or swine species to humans. Here we focus first on the simpler problem of the much smaller human individual evolutionary amino acid mutational changes in NA, which cleaves sialic acid groups and is required for influenza virus replication. Our thermodynamic panorama shows that very small amino acid changes can be monitored very accurately across many historic (1945–2011 Uniprot and NCBI strains using hydropathicity scales to quantify the roughness of water film packages. Quantitative sequential analysis is most effective with the fractal differential hydropathicity scale based on protein self-organized criticality (SOC. Our analysis shows that large-scale vaccination programs have been responsible for a very large convergent reduction in common influenza severity in the last century. Hydropathic analysis is capable of interpreting and even predicting trends of functional changes in mutation prolific viruses directly from amino acid sequences alone. An engineered strain of NA1 is described which could well be significantly less virulent than current circulating strains.

  1. Identification of Low- and High-Impact Hemagglutinin Amino Acid Substitutions That Drive Antigenic Drift of Influenza A(H1N1) Viruses

    Harvey, William T.; Benton, Donald J.; Gregory, Victoria; Hall, James P. J.; Daniels, Rodney S.; Bedford, Trevor; Haydon, Daniel T.; Hay, Alan J.; McCauley, John W.; Reeve, Richard


    Determining phenotype from genetic data is a fundamental challenge. Identification of emerging antigenic variants among circulating influenza viruses is critical to the vaccine virus selection process, with vaccine effectiveness maximized when constituents are antigenically similar to circulating viruses. Hemagglutination inhibition (HI) assay data are commonly used to assess influenza antigenicity. Here, sequence and 3-D structural information of hemagglutinin (HA) glycoproteins were analyzed together with corresponding HI assay data for former seasonal influenza A(H1N1) virus isolates (1997–2009) and reference viruses. The models developed identify and quantify the impact of eighteen amino acid substitutions on the antigenicity of HA, two of which were responsible for major transitions in antigenic phenotype. We used reverse genetics to demonstrate the causal effect on antigenicity for a subset of these substitutions. Information on the impact of substitutions allowed us to predict antigenic phenotypes of emerging viruses directly from HA gene sequence data and accuracy was doubled by including all substitutions causing antigenic changes over a model incorporating only the substitutions with the largest impact. The ability to quantify the phenotypic impact of specific amino acid substitutions should help refine emerging techniques that predict the evolution of virus populations from one year to the next, leading to stronger theoretical foundations for selection of candidate vaccine viruses. These techniques have great potential to be extended to other antigenically variable pathogens. PMID:27057693

  2. Influenza A(H1N1) pandemic: 2 years after

    ALLAM, M.F.


    In 2009, the emergence of the new H1N1 influenza virus saw the world brace itself for the first influenza pandemic since 1968. Two years after, it is time to evaluate the situation of that Influenza A(H1N1) pandemic and its combat measures.

  3. Kinetics of lung lesion development and pro-inflammatory cytokine response in pigs with vaccine-associated enhanced respiratory disease induced by challenge with pandemic (2009) A/H1N1 influenza virus

    The objective of this report was to characterize the enhanced clinical disease and lung lesions observed in pigs vaccinated with inactivated H1N2 swine delta-cluster influenza A virus and challenged with pandemic 2009 A/H1N1 human influenza virus. Eighty-four, six-week-old, crossbred pigs were rand...

  4. Predominance of influenza A(H1N1)pdm09 virus genetic subclade 6B.1 and influenza B/Victoria lineage viruses at the start of the 2015/16 influenza season in Europe

    Broberg, E.; Melidou, A; Prosenc, Katarina; BRAGSTAD, K.; Hungnes, Olav; Schweiger, Brunhilde; Wedde, Marianne; Biere, Barbara; Buda, Silke


    Influenza A(H1N1)pdm09 viruses predominated in the European influenza 2015/16 season. Most analysed viruses clustered in a new genetic subclade 6B.1, antigenically similar to the northern hemisphere vaccine component A/California/7/2009. The predominant influenza B lineage was Victoria compared with Yamagata in the previous season. It remains to be evaluated at the end of the season if these changes affected the effectiveness of the vaccine for the 2015/16 season.

  5. IL-17 response mediates acute lung injury induced by the 2009 Pandemic Influenza A(H1N1)Virus

    Chenggang Li; Chen Wang; Zhongwei Chen; Li Xing; Chong Tang; Xiangwu Ju; Feng Guo; Jiejie Deng; Yan Zhao; Peng Yang; Jun Tang; Penghui Yang; Huanling Wang; Zhongpeng Zhao; Zhinan Yin; Bin Cao; Xiliang Wang; Chengyu Jiang; Yang Sun; Taisheng Li; Chen Wang; Zhong Wang; Zhen Zou; Yiwu Yan; Wei Wang


    The 2009 flu pandemic involved the emergence of a new strain of a swine-origin H1N1 influenza virus(S-OIV H1N1)that infected almost every country in the world.Most infections resulted in respiratory illness and some severe cases resulted in acute lung injury.In this report,we are the first to describe a mouse model of S-OIV virus infection with acute lung injury and immune responses that reflect human clinical disease.The clinical efficacy of the antiviral oseltamivir(Tamiflu)administered in the early stages of S-OIV H1N1 infection was confirmed in the mouse model.Moreover,elevated levels of IL-17,Th-17 mediators and IL-17-responsive cytokines were found in serum samples of S-OIV-infected patients in Beijing.IL-17 deficiency or treatment with monoclonal antibodies against IL-17-ameliorated acute lung injury induced by the S-OIV H1N1 virus in mice.These results suggest that IL-17 plays an important role in S-OIV-induced acute lung injury and that monoclonal antibodies against IL-17 could be useful as a potential therapeutic remedy for future S-OIV H1N1 pandemics.

  6. Live attenuated influenza A virus vaccine protects against A(H1N1)pdm09 heterologous challenge without vaccine associated enhanced respiratory disease.

    Gauger, Phillip C; Loving, Crystal L; Khurana, Surender; Lorusso, Alessio; Perez, Daniel R; Kehrli, Marcus E; Roth, James A; Golding, Hana; Vincent, Amy L


    Live-attenuated influenza virus (LAIV) vaccines may provide cross-protection against contemporary influenza A virus (IAV) in swine. Conversely, whole inactivated virus (WIV) vaccines have the potential risk of vaccine-associated enhanced respiratory disease (VAERD) when challenged with IAV of substantial antigenic drift. A temperature sensitive, intranasal H1N2 LAIV was compared to wild type exposure (WT) and an intramuscular WIV vaccine in a model shown to induce VAERD. WIV vaccinated swine challenged with pandemic A/H1N1 (H1N1pdm09) were not protected from infection and demonstrated severe respiratory disease consistent with VAERD. Lung lesions were mild and challenge virus was not detected in the respiratory tract of LAIV vaccinates. High levels of post-vaccination IgG serum antibodies targeting the H1N1pdm09 HA2 stalk domain were exclusively detected in the WIV group and associated with increased H1N1pdm09 virus infectivity in MDCK cells. In contrast, infection-enhancing antibodies were not detected in the serum of LAIV vaccinates and VAERD was not observed. PMID:25461535

  7. Protein profiling of nasopharyngeal aspirates of hospitalized and outpatients revealed cytokines associated with severe influenza A(H1N1)pdm09 virus infections: A pilot study.

    Fu, Yu; Gaelings, Lana; Jalovaara, Petri; Kakkola, Laura; Kinnunen, Mervi T; Kallio-Kokko, Hannimari; Valkonen, Miia; Kantele, Anu; Kainov, Denis E


    Influenza A viruses (IAV) mutate rapidly and cause seasonal epidemics and occasional pandemics, which result in substantial number of patient visits to the doctors and even hospitalizations. We aimed here to identify inflammatory proteins, which levels correlated to clinical severity of the disease. For this we analysed 102 cytokines and growth factors in human nasopharyngeal aspirate (NPA) samples of 27 hospitalized and 27 outpatients diagnosed with influenza A(H1N1)pdm09 virus infection. We found that the relative levels of monocyte differentiation antigen CD14, lipocalin-2 (LCN2), C-C-motif chemokine 20 (CCL20), CD147, urokinase plasminogen activator surface receptor (uPAR), pro-epidermal growth factor (EGF), trefoil factor 3 (TFF3), and macrophage migration inhibitory factor (MIF) were significantly lower (padiponectin, and chitinase-3-like 1 (CHI3L1) were significantly higher (padiponectin and CHI3L1 levels have already been correlated with severity of IAV infection in mice and humans, our study is the first to describe association of CD147, RBP4, TFF3, and CFD with hospitalization of IAV-infected patients. Thus, we identified local innate immune profiles, which were associated with the clinical severity of influenza infections. PMID:27442005

  8. Characteristic amino acid changes of influenza A(H1N1)pdm09 virus PA protein enhance A(H7N9) viral polymerase activity.

    Liu, Jun; Huang, Feng; Zhang, Junsong; Tan, Likai; Lu, Gen; Zhang, Xu; Zhang, Hui


    Human coinfection with a novel H7N9 influenza virus and the 2009 pandemic A(H1N1) influenza virus, H1N1pdm09, has recently been reported in China. Because reassortment can occur during coinfection, it is necessary to clarify the effects of gene reassortment between these two viruses. Among the viral ribonucleoprotein complex (vRNP) genes, only the PA gene of H1N1pdm09 enhances the avian influenza viral polymerase activity. Based on a phylogenetic analysis, we show a special evolutionary feature of the H1N1pdm09 PA gene, which clustered with those of the novel H7N9 virus and related H9N2 viruses, rather than in the outgroup as the H1N1pdm09 genes do on the phylogenetic trees of other vRNP genes. Using a minigenome system of the novel H7N9 virus, we further demonstrate that replacement of its PA gene significantly enhanced its polymerase activity, whereas replacement of the other vRNP genes reduced its polymerase activity. We also show that the residues of PA evolutionarily conserved between H1N1pdm09 and the novel H7N9 virus are associated with attenuated or neutral polymerase activity. The mutations associated with the increased activity of the novel H7N9 polymerase are characteristic of the H1N1pdm09 gene, and are located almost adjacent to the surface of the PA protein. Our results suggest that the novel H7N9 virus has more effective PB1, PB2, and NP genes than H1N1pdm09, and that H1N1pdm09-like PA mutations enhance the novel H7N9 polymerase function. PMID:26980671

  9. Influenza A/H1N1 Severe Pneumonia: Novel Morphocytological Findings in Bronchoalveolar Lavage

    Paola Faverio


    Full Text Available We present the results of bronchoalveolar lavage (BAL performed in three patients with severe influenza A/H1N1 pneumonia complicated by acute respiratory distress syndrome (ARDS. Light microscopy analysis of BAL cytocentrifugates showed the presence of characteristic large, mononuclear, plasmoblastic/plasmocytoid-like cells never described before. Via transmission electron microscopy, these cells were classified as atypical type II pneumocytes and some of them showed cytoplasmic vesicles and inclusions. We concluded that plasmoblastic/plasmocytoid-like type II pneumocytes might represent a morphologic marker of A/H1N1 influenza virus infection as well as reparative cellular activation after diffuse alveolar damage.

  10. A study of analysis PB1-F2 protein of Influenza Viruses A/H1N1pdm09, A/ H3N2, and A/H5N1

    Hana Apsari Pawestri


    Full Text Available Abstrak Tujuan. Protein PB1-F2 (polymerase basic 1-frame 2 adalah protein terbaru yang ditemukan pada virus Influenza dan telah terbukti berperan dalam induksi kematian sel dan patogenitas. Tujuan dari tulisan ini adalah untuk menganalisis protein PB1-F2 pada virus Influenza A/H5N1 dan A/H1N1pdm09. Metode. Kami melakukan pencarian data yang relevan yaitu sekuens gen virus Influenza A/H5N1 dan A/H1N1pdm09 dari Gen Bank National Center for Biotechnology Information (NCBI selama tahun 1997-2015. Data yang digunakan adalah data sekuens nukleotida gen PB1 (polymerase basic1 virus influenza A/H5N1 dan A/H1N1pdm09. Kemudian dilakukan analisis alignment untuk mengetahui variasi protein dan mutasi yang berhubungan dengan patogenitas dan virulensi. Hasil. Kami melakukan penelitian terhadap sekuens PB1-F2 sebanyak 3262 influenza A/H5N1 dan 2472 Influenza A/H1N1pdm09. Hasil analisis menunjukkan bahwa semua sekuens A/H5N1 memiliki panjang yang penuh sebanyak 90 asam amino, kecuali influenza pandemi 2009 hanya memiliki panjang 87 asam amino. Kemudian, ditemukan mutasi yang berhubungan dengan virulensi yang ditunjukan dengan perubahan asam amino Asparagin (N menjadi Serin (S. Mutasi tersebut terjadi pada Influenza A/H5N1 sebanyak 8.5% dan Influenza A/H1N1pdm09 sebanyak 0.5%. Kesimpulan. Ditemukan beberapa variasi panjang asam amino dan mutasi penting pada sekuens PB1-F2 dari subtipe yang berbeda yaitu influenza A/H5N1 dan A/H1N1pdm09  yang mengindikasikan seleksi spesifik karena introduksi dan adaptasi terhadap inang yang berbeda. Diperlukan penelitian lanjutan untuk lebih memahami variasi dan kontribusi protein PB1-F2 tersebut terhadap virulensi dan patogenitas virus Influenza. Kata kunci : Patogenesis, Virus Influenza, Protein  PB1-F2 Abstract Aim. Influenza virus PB1-F2 (polymerase basic 1-frame 2 protein is a novel protein previously shown to be involved in cell death induction and pathogenesis. Here we analysis the PB1-F2 protein of Influenza virus A

  11. Report of two cases of influenza virus A/H1N1v and B co-infection during the 2010/2011 epidemics in the Italian Veneto Region

    Calistri Arianna; Salata Cristiano; Cosentino Marina; Asnicar Samuele; Franchin Elisa; Cusinato Riccardo; Pacenti Monia; Donatelli Isabella; Palù Giorgio


    Abstract From October 2010 to April 2011, in the Italian Veneto Region, 1403 hospitalized patients were tested for influenza virus infection by specific real time RT-PCR. Overall, 327 samples were positive for either influenza A (75%) or B (25%) viruses. Among these positive patients two resulted co-infected by A/H1N1v and B viruses. Even though co-infection with both influenza A and B viruses appears to be a rare event, it occurs naturally and may play a role in epidemiology and pathogenicit...

  12. Outbreak of pandemic influenza A/H1N1 2009 in Nepal

    Shrestha Sirjana; Prakash KC Khagendra; Upadhyay Bishnu; Shakya Geeta; Adhikari Bal Ram; Dhungana Guna


    Abstract Background The 2009 flu pandemic is a global outbreak of a new strain of H1N1 influenza virus. Pandemic influenza A (H1N1) 2009 has posed a serious public health challenge world-wide. Nepal has started Laboratory diagnosis of Pandemic influenza A/H1N1 from mid June 2009 though active screening of febrile travellers with respiratory symptoms was started from April 27, 2009. Results Out of 609 collected samples, 302 (49.6%) were Universal Influenza A positive. Among the influenza A pos...

  13. Seroprevalence of antibodies to influenza A/H1N1/2009 among transmission risk groups after the second wave in Mexico, by a virus-free ELISA method

    Elizondo-Montemayor, Leticia; Alvarez, Mario M.; Hernández-Torre, Martín; Ugalde-Casas, Patricia A.; Lam-Franco, Lorena; Bustamante-Careaga, Humberto; Castilleja-Leal, Fernando; Contreras-Castillo, Julio; Moreno-Sánchez, Héctor; Tamargo-Barrera, Daniela; López-Pacheco, Felipe; Freiden, Pamela J.; Schultz-Cherry, Stacey


    Summary Objective No serological studies have been performed in Mexico to assess the seroprevalence of influenza A/H1N1/2009 in groups of people according to the potential risk of transmission. The aim of this study was to determine the seroprevalence of antibodies against influenza A/H1N1/2009 in subjects in Mexico grouped by risk of transmission. Methods Two thousand two hundred and twenty-two subjects were categorized into one of five occupation groups according to the potential risk of transmission: (1) students, (2) teachers, (3) healthcare workers, (4) institutional home residents aged >60 years, and (5) general population. Seroprevalence by potential transmission group and by age grouped into decades was determined by a virus-free ELISA method based on the recombinant receptor-binding domain of the hemagglutinin of influenza A/H1N1/2009 virus as antigen (85% sensitivity; 95% specificity). The Wilson score, Chi-square test, and logistic regression models were used for the statistical analyses. Results Seroprevalence for students was 47.3%, for teachers was 33.9%, for older adults was 36.5%, and for the general population was 33.0%, however it was only 24.6% for healthcare workers (p = 0.011). Of the students, 56.6% of those at middle school, 56.4% of those at high school, 52.7% of those at elementary school, and 31.1% of college students showed positive antibodies (p < 0.001). Seroprevalence was 44.6% for college teachers, 31.6% for middle school teachers, and 29.8% for elementary school teachers, but was only 20.3% for high school teachers (p = 0.002). Conclusions The student group was the group most affected by influenza A/H1N1/2009, while the healthcare worker group showed the lowest prevalence. Students represent a key target for preventive measures. PMID:21855383

  14. Demand for care and nosocomial infection rate during the first influenza AH1N1 2009 virus outbreak at a referral hospital in Mexico City Demanda asistencial y tasa de infección nosocomial durante el primer brote de influenza AH1N1 2009 en un hospital de referencia en la Ciudad de México

    Rogelio Pérez-Padilla


    Full Text Available OBJECTIVE: Comparison of routine hospital indicators (consults at the Emergency Room (ER and hospital admissions during the 2009 pandemic of the influenza AH1N1 virus at the national referral hospital for respiratory diseases in Mexico City. MATERIAL AND METHODS: The outbreak was from April to mid-May 2009 and two control periods were used:2009 (before and after the outbreak,and during April-May from 2007 and 2008. RESULTS: During the outbreak total consultation at the ER increased six times compared with the 2007-2008 control period and 11 times compared with the 2009 control period. Pneumonia- or influenza-related ER consultations increased 23.2 and 15.3%, respectively. The rate of nosocomial infection during the outbreak was 13.6 and that of nosocomial pneumonia was 6 per/100 hospital discharges, a two-fold and three-fold increase compared to the control periods respectively. CONCLUSIONS: During the outbreak,mean severity of admitted patients increased,with a rise in in-hospital mortality and nosocomial infections rate, including nosocomial pneumonia.OBJETIVO: Comparación de indicadores hospitalarios de rutina (consultas de urgencia, admisiones hospitalarias etc. durante la pandemia de influenzaAH1N1 2009 en un hospital de referencia para enfermedades respiratorias de la Ciudad de México. MATERIAL Y MÉTODOS: El brote se consideró de abril a la mitad de mayo de 2009 y se comparó con dos periodos control: el de 2009 (antes y después del brote, y durante abril y mayo de 2007 y 2008. RESULTADOS: Durante el brote las consultas de urgencia crecieron seis veces comparadas con el periodo control 2007-2008 y 11 veces contra el periodo control de 2009. Las consultas por neumonía o influenza incrementaron 23.2 y 15.3% comparadas contra los periodos control, respectivamente. La tasa de infección nosocomial durante el brote fue de 13.6 y la de neumonía nosocomial de 6.0 por 100 egresos hospitalarios, el doble y el triple de la documentada en los

  15. Polymeric LabChip real-time PCR as a point-of-care-potential diagnostic tool for rapid detection of influenza A/H1N1 virus in human clinical specimens.

    Hyun-Ok Song

    Full Text Available It is clinically important to be able to detect influenza A/H1N1 virus using a fast, portable, and accurate system that has high specificity and sensitivity. To achieve this goal, it is necessary to develop a highly specific primer set that recognizes only influenza A viral genes and a rapid real-time PCR system that can detect even a single copy of the viral gene. In this study, we developed and validated a novel fluidic chip-type real-time PCR (LabChip real-time PCR system that is sensitive and specific for the detection of influenza A/H1N1, including the pandemic influenza strain A/H1N1 of 2009. This LabChip real-time PCR system has several remarkable features: (1 It allows rapid quantitative analysis, requiring only 15 min to perform 30 cycles of real-time PCR. (2 It is portable, with a weight of only 5.5 kg. (3 The reaction cost is low, since it uses disposable plastic chips. (4 Its high efficiency is equivalent to that of commercially available tube-type real-time PCR systems. The developed disposable LabChip is an economic, heat-transferable, light-transparent, and easy-to-fabricate polymeric chip compared to conventional silicon- or glass-based labchip. In addition, our LabChip has large surface-to-volume ratios in micro channels that are required for overcoming time consumed for temperature control during real-time PCR. The efficiency of the LabChip real-time PCR system was confirmed using novel primer sets specifically targeted to the hemagglutinin (HA gene of influenza A/H1N1 and clinical specimens. Eighty-five human clinical swab samples were tested using the LabChip real-time PCR. The results demonstrated 100% sensitivity and specificity, showing 72 positive and 13 negative cases. These results were identical to those from a tube-type real-time PCR system. This indicates that the novel LabChip real-time PCR may be an ultra-fast, quantitative, point-of-care-potential diagnostic tool for influenza A/H1N1 with a high sensitivity and

  16. Comparison of Influenza Outbreaks in the Republic of Kazakhstan and Russia Induced by 2009 Yearly New Variant of A(H1N1)Influenza Virus

    Karpova L S; Ospanov K S; Baiserkin B S; Boibosinov E U; Popovtseva N M; Stolyarova T P; Stolyarov K A; Mamadaliyev S M; Khairullin B M; Sandybayev N T; Kydyrbayev Zh K; Orynbayev M B


    The aim of the work is the comparison of the epidemiology of influenza and acute respiratory virus infections(ARVI)in the Republic of Kazakhstan with the corresponding influenza epidemic in Russia induced by influenza pandemic virus A/California/07/2009 in 2009. Data on influenza and ARVI from the Republic of Kazakhstan and Federal Center of influenza was collected and investigated over the course of several weeks from hospitalized patients with the same diagnosis among all population and in age groups on 16 territories of Kazakhstan and in 49 major cities of Russia. The epidemic in Kazakhstan resembled the Russian epidemic in terms of its abnormally early beginning,expression of monoaetiology,the spread of the epidemic into all territories and start of the epidemics among adult population. High percentage of hospitalized people and lethal outcome were registered in this epidemic. Similarity of epidemic process character in corresponding border-line territories of both countries was found out.

  17. Influenza A(H1N1)pdm09 virus exhibiting enhanced cross-resistance to oseltamivir and peramivir due to a dual H275Y/G147R substitution, Japan, March 2016.

    Takashita, Emi; Fujisaki, Seiichiro; Shirakura, Masayuki; Nakamura, Kazuya; Kishida, Noriko; Kuwahara, Tomoko; Shimazu, Yukie; Shimomura, Takeshi; Watanabe, Shinji; Odagiri, Takato


    An influenza A(H1N1)pdm09 virus carrying a G147R substitution in combination with an H275Y substitution in the neuraminidase protein, which confers cross-resistance to oseltamivir and peramivir, was detected from an immunocompromised inpatient in Japan, March 2016. This dual H275Y/G147R mutant virus exhibited enhanced cross-resistance to both drugs compared with the single H275Y mutant virus and reduced susceptibility to zanamivir, although it showed normal inhibition by laninamivir. PMID:27336226

  18. Rapid spread of influenza A(H1N1)pdm09 viruses with a new set of specific mutations in the internal genes in the beginning of 2015/2016 epidemic season in Moscow and Saint Petersburg (Russian Federation).

    Komissarov, Andrey; Fadeev, Artem; Sergeeva, Maria; Petrov, Sergey; Sintsova, Kseniya; Egorova, Anna; Pisareva, Maria; Buzitskaya, Zhanna; Musaeva, Tamila; Danilenko, Daria; Konovalova, Nadezhda; Petrova, Polina; Stolyarov, Kirill; Smorodintseva, Elizaveta; Burtseva, Elena; Krasnoslobodtsev, Kirill; Kirillova, Elena; Karpova, Lyudmila; Eropkin, Mikhail; Sominina, Anna; Grudinin, Mikhail


    A dramatic increase of influenza activity in Russia since week 3 of 2016 significantly differs from previous seasons in terms of the incidence of influenza and acute respiratory infection (ARI) and in number of lethal cases. We performed antigenic analysis of 108 and whole-genome sequencing of 77 influenza A(H1N1)pdm09 viruses from Moscow and Saint Petersburg. Most of the viruses were antigenically related to the vaccine strain. Whole-genome analysis revealed a composition of specific mutations in the internal genes (D2E and M83I in NEP, E125D in NS1, M105T in NP, Q208K in M1, and N204S in PA-X) that probably emerged before the beginning of 2015/2016 epidemic season. PMID:26992820

  19. A(H1N1)流感病毒及抗病毒新药的筛选%A(H1N1) Influenza Virus and Screening of New Anti-influenza Virus Drugs



    A(H1N1) influenza virus is a novel strain of influenza virus mutant,which was found in March to April 2009 in USA and Mexico. The spread of epidemic influenza brings about a serious attention by every country in the world and World Health Organization. In this paper, the A (H1N1) influenza virus and its symptom, virulence and spread are introduced. Meanwhile, the mutant' s resistance to anti-influenza drugs, the characterization of the 1918 pandemic influenza virus polymerase, the crystal structure of human and avian influenza virus polymerase and its action in influenza are also discussed. Accordingly, we put forward the screening ideas and research orientation for anti-influenza virus drugs, which will be a beneficial reference for the further design and development of new anti-influenza virus drugs.%A(H1N1)流感病毒是2009年3~4月在美国和墨西哥发现的一种流感病毒变异的新病毒株.这类流感疫情的蔓延引起了世界各国和世界卫生组织的严重关注.本文介绍了A(H1N1)流感新病毒株及感染这种病毒患者的症状,A(H1N1)流感病毒的致命力和传播,流感病毒变异对抗病毒药的抗药性,以及1918年流感大流行病毒聚合酶特性,人流感病毒和禽流感病毒聚合酶的结晶结构及其在感染中的作用.据此,提出了抗流感病毒药的筛选思路和研究方向,为抗流感病毒新药的设计和开发提供有益的参考.

  20. Reproductive number and serial interval of the first wave of influenza A(H1N1pdm09 virus in South Africa.

    Brett N Archer

    Full Text Available BACKGROUND/OBJECTIVE: Describing transmissibility parameters of past pandemics from diverse geographic sites remains critical to planning responses to future outbreaks. We characterize the transmissibility of influenza A(H1N1pdm09 (hereafter pH1N1 in South Africa during 2009 by estimating the serial interval (SI, the initial effective reproductive number (initial R(t and the temporal variation of R(t. METHODS: We make use of data from a central registry of all pH1N1 laboratory-confirmed cases detected throughout South Africa. Whenever date of symptom onset is missing, we estimate it from the date of specimen collection using a multiple imputation approach repeated 100 times for each missing value. We apply a likelihood-based method (method 1 for simultaneous estimation of initial R(t and the SI; estimate initial R(t from SI distributions established from prior field studies (method 2; and the Wallinga and Teunis method (method 3 to model the temporal variation of R(t. RESULTS: 12,360 confirmed pH1N1 cases were reported in the central registry. During the period of exponential growth of the epidemic (June 21 to August 3, 2009, we simultaneously estimate a mean R(t of 1.47 (95% CI: 1.30-1.72 and mean SI of 2.78 days (95% CI: 1.80-3.75 (method 1. Field studies found a mean SI of 2.3 days between primary cases and laboratory-confirmed secondary cases, and 2.7 days when considering both suspected and confirmed secondary cases. Incorporating the SI estimate from field studies using laboratory-confirmed cases, we found an initial R(t of 1.43 (95% CI: 1.38-1.49 (method 2. The mean R(t peaked at 2.91 (95% CI: 0.85-2.91 on June 21, as the epidemic commenced, and R(t>1 was sustained until August 22 (method 3. CONCLUSIONS: Transmissibility characteristics of pH1N1 in South Africa are similar to estimates reported by countries outside of Africa. Estimations using the likelihood-based method are in agreement with field findings.

  1. Contact Tracing for Influenza A(H1N1)pdm09 Virus–infected Passenger on International Flight

    Shankar, Ananda G.; Janmohamed, Kulsum; Olowokure, Babatunde; Smith, Gillian E.; Hogan, Angela H.; De Souza, Valerie; Wallensten, Anders; Oliver, Isabel; Blatchford, Oliver; Cleary, Paul; Ibbotson, Sue


    In April 2009, influenza A(H1N1)pdm09 virus infection was confirmed in a person who had been symptomatic while traveling on a commercial flight from Mexico to the United Kingdom. Retrospective public health investigation and contact tracing led to the identification of 8 additional confirmed cases among passengers and community contacts of passengers.

  2. Analysis of fatal outcomes from influenza A(H1N1pdm09 in Mongolia

    Erdenebaatariin Soyolmaa


    Full Text Available Introduction: While influenza A(H1N1pdm09 usually causes mild illness in the majority of people, there have been reports of severe cases and deaths. As there is no documented evidence on fatal outcomes from influenza in Mongolia previously, we aimed to describe the epidemiology of fatal influenza A(H1N1pdm09 cases to provide recommendations to assist the national influenza prevention and control strategy.Methods: We selected influenza A(H1N1pdm09-confirmed deaths in hospitals between 12 October 2009 and 31 January 2010 in Mongolia from the national influenza surveillance system. The mortality rate and case fatality rate (CFR of influenza A(H1N1pdm09-hospitalized deaths were calculated. Using country prevalence of pregnancy and chronic diseases, we calculated the relative risk of death from influenza A(H1N1pdm09.Results: There were 29 deaths with a mortality rate of 1.0 per 100 000 population during the study period, which was highest in children under five and the middle-aged population. Crude CFR was 2.2%. Of all fatal cases, 62% had at least one underlying condition. Most (62% were provided antivirals, although none received these within 48 hours of symptom onset. Prevalence for pregnancy, cardiovascular and chronic liver diseases was five to 50 times higher in fatal cases compared to country prevalence.Discussion: Mortality and crude CFR in our study was higher than in other studies. However, due to the diagnostic policy change during the epidemic, this estimate is likely to have overestimated actual case fatalities. Pregnancy, cardiovascular and chronic liver diseases were suggestive risk factors for death from influenza A(H1N1pdm09. Strengthening hospital-based influenza surveillance is important in predicting severity of an epidemic and responding to influenza epidemics in a timely and appropriate manner.

  3. A polyvalent influenza A DNA vaccine induces heterologous immunity and protects pigs against pandemic A(H1N1)pdm09 virus infection

    Bragstad, Karoline; Vinner, Lasse; Hansen, Mette Sif;


    The composition of current influenza protein vaccines has to be reconsidered every season to match the circulating influenza viruses, continuously changing antigenicity. Thus, influenza vaccines inducing a broad cross-reactive immune response would be a great advantage for protection against both....... The ability of this DNA vaccine to limit virus shedding may have an impact on virus spread among pigs which could possibly extend to humans as well, thereby diminishing the risk for epidemics and pandemics to evolve....... antibodies >40 HAU/ml seven days after second vaccination. Heterologous virus challenge as long as ten weeks after last immunisation was able to trigger a vaccine antibody HI response 26 times higher than in the control pigs. The H3N2 DNA vaccine HA and NA genes also triggered an effective vaccine response...


    Kotlyarov, R.; Kuprianov, V.; Migunov, A.; Stepanova, L.; Tsybalova, L.; Kiselev, O.; Ravin, N.; Skryabin, K.


    The conventional vaccines currently being used to deal with influenza are based on a virus obtained in chicken embryos or its components. The high variability of the major immunogenic surface proteins – hemagglutinin and neuraminidase–require the development of strain–specific vaccines that match the antigenic specificity of a newly emerging virus. Recombinant vaccines based on single viral proteins that could be easily produced in standard expression systems are attractive alternatives to tr...

  5. Student behavior during a school closure caused by pandemic influenza A/H1N1.

    Joel C Miller

    Full Text Available BACKGROUND: Many schools were temporarily closed in response to outbreaks of the recently emerged pandemic influenza A/H1N1 virus. The effectiveness of closing schools to reduce transmission depends largely on student/family behavior during the closure. We sought to improve our understanding of these behaviors. METHODOLOGY/PRINCIPAL FINDINGS: To characterize this behavior, we surveyed students in grades 9-12 and parents of students in grades 5-8 about student activities during a week long closure of a school during the first months after the disease emerged. We found significant interaction with the community and other students-though less interaction with other students than during school-with the level of interaction increasing with grade. CONCLUSIONS: Our results are useful for the future design of social distancing policies and to improving the ability of modeling studies to accurately predict their impact.

  6. Production of polyclonal antibody against Tehran strain influenza virus (A/H1N1/2009 hemagglutinin conserved domain (HA2: brief report

    Somayeh Zamani


    Full Text Available Background: The influenza virus is one of the most important factors for higher morbidity and mortality in the world. Recently, researchers have been focused on influenza conserved antigenic proteins such as hemagglutinin stalk domain (HA2 for vaccine production and serological studies. The HA2 plays a major role in the fusion of the virus with host cells membrane. The immunity system enables to produce antibody against HA2. The aim of this study is polyclonal antibody production against influenza HA2. Methods: This study was done in the Influenza Research Lab, Pasteur Institute of Iran, Tehran for one year from September 2013 to October 2014. In the present study, recombinant HA2 protein was produced in prokaryotic system and purified using Nickel affinity chromatography. The purified HA2 was mixed with Freund’s adjuvant (complete and incomplete and injected into two New Zealand white rabbits by intramuscularly and subcutaneously routes. Immunization was continued for several months with two weeks interval. Before each immunization, blood was drawn by venous puncture from the rabbit ear. Function of rabbit's sera was evaluated using radial immunodiffusion (RID in both forms, Single RID (SRID and Double RID (DRID. Finally, antiserum activity against HA2 was evaluated using western blotting as serological assay. Results: Sedimentary line and zone was observed in RID assays (SRID and DRID represent interaction between HA2 protein and anti- HA2 antibody. As well as, western blotting results was positive for HA2 protein. Therefore, these results showed that polyclonal antibody produced against HA2 protein can identify HA2 protein antigenic sites. Conclusion: These findings show that humoral immune responses have properly been stimulated in rabbits and these antibodies can identify HA2 protein and may be suitable for other serological methods.

  7. Characterizing the epidemiology of the 2009 influenza A/H1N1 pandemic in Mexico.

    Gerardo Chowell


    Full Text Available BACKGROUND: Mexico's local and national authorities initiated an intense public health response during the early stages of the 2009 A/H1N1 pandemic. In this study we analyzed the epidemiological patterns of the pandemic during April-December 2009 in Mexico and evaluated the impact of nonmedical interventions, school cycles, and demographic factors on influenza transmission. METHODS AND FINDINGS: We used influenza surveillance data compiled by the Mexican Institute for Social Security, representing 40% of the population, to study patterns in influenza-like illness (ILIs hospitalizations, deaths, and case-fatality rate by pandemic wave and geographical region. We also estimated the reproduction number (R on the basis of the growth rate of daily cases, and used a transmission model to evaluate the effectiveness of mitigation strategies initiated during the spring pandemic wave. A total of 117,626 ILI cases were identified during April-December 2009, of which 30.6% were tested for influenza, and 23.3% were positive for the influenza A/H1N1 pandemic virus. A three-wave pandemic profile was identified, with an initial wave in April-May (Mexico City area, a second wave in June-July (southeastern states, and a geographically widespread third wave in August-December. The median age of laboratory confirmed ILI cases was ∼ 18 years overall and increased to ∼ 31 years during autumn (p<0.0001. The case-fatality ratio among ILI cases was 1.2% overall, and highest (5.5% among people over 60 years. The regional R estimates were 1.8-2.1, 1.6-1.9, and 1.2-1.3 for the spring, summer, and fall waves, respectively. We estimate that the 18-day period of mandatory school closures and other social distancing measures implemented in the greater Mexico City area was associated with a 29%-37% reduction in influenza transmission in spring 2009. In addition, an increase in R was observed in late May and early June in the southeast states, after mandatory school

  8. Nosocomial Co-Transmission of Avian Influenza A(H7N9) and A(H1N1)pdm09 Viruses between 2 Patients with Hematologic Disorders.

    Chen, Huazhong; Liu, Shelan; Liu, Jun; Chai, Chengliang; Mao, Haiyan; Yu, Zhao; Tang, Yuming; Zhu, Geqin; Chen, Haixiao X; Zhu, Chengchu; Shao, Hui; Tan, Shuguang; Wang, Qianli; Bi, Yuhai; Zou, Zhen; Liu, Guang; Jin, Tao; Jiang, Chengyu; Gao, George F; Peiris, Malik; Yu, Hongjie; Chen, Enfu


    A nosocomial cluster induced by co-infections with avian influenza A(H7N9) and A(H1N1)pdm09 (pH1N1) viruses occurred in 2 patients at a hospital in Zhejiang Province, China, in January 2014. The index case-patient was a 57-year-old man with chronic lymphocytic leukemia who had been occupationally exposed to poultry. He had co-infection with H7N9 and pH1N1 viruses. A 71-year-old man with polycythemia vera who was in the same ward as the index case-patient for 6 days acquired infection with H7N9 and pH1N1 viruses. The incubation period for the second case-patient was estimated to be <4 days. Both case-patients died of multiple organ failure. Virus genetic sequences from the 2 case-patients were identical. Of 103 close contacts, none had acute respiratory symptoms; all were negative for H7N9 virus. Serum samples from both case-patients demonstrated strong proinflammatory cytokine secretion but incompetent protective immune responses. These findings strongly suggest limited nosocomial co-transmission of H7N9 and pH1N1 viruses from 1 immunocompromised patient to another. PMID:26982379

  9. Nosocomial Co-Transmission of Avian Influenza A(H7N9) and A(H1N1)pdm09 Viruses between 2 Patients with Hematologic Disorders

    Chen, Huazhong; Liu, Shelan; Liu, Jun; Chai, Chengliang; Mao, Haiyan; Yu, Zhao; Tang, Yuming; Zhu, Geqin; Chen, Haixiao X.; Zhu, Chengchu; Shao, Hui; Tan, Shuguang; Wang, Qianli; Bi, Yuhai; Zou, Zhen; Liu, Guang; Jin, Tao; Jiang, Chengyu; Gao, George F.; Peiris, Malik


    A nosocomial cluster induced by co-infections with avian influenza A(H7N9) and A(H1N1)pdm09 (pH1N1) viruses occurred in 2 patients at a hospital in Zhejiang Province, China, in January 2014. The index case-patient was a 57-year-old man with chronic lymphocytic leukemia who had been occupationally exposed to poultry. He had co-infection with H7N9 and pH1N1 viruses. A 71-year-old man with polycythemia vera who was in the same ward as the index case-patient for 6 days acquired infection with H7N9 and pH1N1 viruses. The incubation period for the second case-patient was estimated to be <4 days. Both case-patients died of multiple organ failure. Virus genetic sequences from the 2 case-patients were identical. Of 103 close contacts, none had acute respiratory symptoms; all were negative for H7N9 virus. Serum samples from both case-patients demonstrated strong proinflammatory cytokine secretion but incompetent protective immune responses. These findings strongly suggest limited nosocomial co-transmission of H7N9 and pH1N1 viruses from 1 immunocompromised patient to another. PMID:26982379

  10. Importation and spread of pandemic influenza virus a(H1N1 in Autonomous Province of vojvodina in preepidemic period

    Ristić Mioljub


    Full Text Available Introduction. Influenza is the most frequently reported communicable disease, having epidemic and pandemic potential. The first influenza pandemic in this century started in Mexico and spread quickly throughout the world. This paper analyses importation of pandemic influenza cases and local transmission among population in the Autonomous Province of Vojvodina. Material and methods. According to the WHO guidelines and national recommendations, the influenza surveillance activities were conducted in Vojvodina in order to detect, isolate and treat affected international travelers and their close contacts. Patients whose pandemic influenza infection was laboratory confirmed were classified as confirmed cases, while those with symptoms who were epidemiologically linked with confirmed cases were classified as probable cases. Results. During the period from the 24th of June to 17th of August 2009, 123 pandemic influenza cases were recorded in Vojvodina. Infection was imported through international travelers and our citizens coming from countries affected by influenza outbreaks. Majority of cases had mild clinical picture. Most frequently reported symptoms were high fever (above 38oC (85.6%, and cough (61.6%. Difficulty in breathing was recorded in 20 (16.0% cases, while pneumonia developed in 4 (3.2% cases but none of the cases required mechanical ventilation. Conclusion. The imported cases of pandemic influenza in the pre-epidemic period led to limited local transmission in general population and caused a small outbreak among visitors of International music festival called EXIT.

  11. Hospitalization in two waves of pandemic influenza A(H1N1) in England.

    Campbell, C N J; Mytton, O T; McLean, E M; Rutter, P D; Pebody, R G; Sachedina, N; White, P J; Hawkins, C; Evans, B; Waight, P A; Ellis, J; Bermingham, A; Donaldson, L J; Catchpole, M


    Uncertainties exist regarding the population risks of hospitalization due to pandemic influenza A(H1N1). Understanding these risks is important for patients, clinicians and policy makers. This study aimed to clarify these uncertainties. A national surveillance system was established for patients hospitalized with laboratory-confirmed pandemic influenza A(H1N1) in England. Information was captured on demographics, pre-existing conditions, treatment and outcomes. The relative risks of hospitalization associated with pre-existing conditions were estimated by combining the captured data with population prevalence estimates. A total of 2416 hospitalizations were reported up to 6 January 2010. Within the population, 4·7 people/100,000 were hospitalized with pandemic influenza A(H1N1). The estimated hospitalization rate of cases showed a U-shaped distribution with age. Chronic kidney disease, chronic neurological disease, chronic respiratory disease and immunosuppression were each associated with a 10- to 20-fold increased risk of hospitalization. Patients who received antiviral medication within 48 h of symptom onset were less likely to be admitted to critical care than those who received them after this time (adjusted odds ratio 0·64, 95% confidence interval 0·44-0·94, P=0·024). In England the risk of hospitalization with pandemic influenza A(H1N1) has been concentrated in the young and those with pre-existing conditions. By quantifying these risks, this study will prove useful in planning for the next winter in the northern and southern hemispheres, and for future pandemics. PMID:21108872

  12. Multidrug resistant 2009 a/h1n1 influenza clinical isolate with a neuraminidase i223r mutation retains its virulence and transmissibility in ferrets

    Vries, Erhard; Kroeze, E.J.B.V.; Stittelaar, Koert; Linster, Martin; Linden, A; Schrauwen, Eefje; Leijten, Lonneke; Amerongen, Geert; Schutten, Martin; Kuiken, Thijs; Osterhaus, Albert; Fouchier, Ron; Boucher, Charles; Herfst, Sander


    textabstractOnly two classes of antiviral drugs, neuraminidase inhibitors and adamantanes, are approved for prophylaxis and therapy against influenza virus infections. A major concern is that influenza virus becomes resistant to these antiviral drugs and spreads in the human population. The 2009 pandemic A/H1N1 influenza virus is naturally resistant to adamantanes. Recently a novel neuraminidase I223R mutation was identified in an A/H1N1 virus showing cross-resistance to the neuraminidase inh...

  13. [Cases of children with influenza AH1N1/2009 in the district of Lodz in two epidemic waves].

    Majda-Stanisławska, Ewa; Sobieraj, Iwona


    High influenza morbidity due to new antigenic strain AH1N1 was announced in Mexico in spring 2009. Influenza pandemic caused by the virus AH1N1/2009 spread around the world. Two pandemic waves were noted in most European countries: the first one was due to summer months migration, the second wave started in the beginning of common influenza season. We present features of both waves in children from the district of Lodz. We describe mild clinical course in 14 children who came from holiday in Spain with influenza and who were hospitalized and treated with osltamimivir due to unpredictable course of new influenza. We also present 22 influenza cases of the autumn pandemic wave, when children with severe complications of influenza and children from high risk groups were hospitalized and treated with antivirals. Experience that we have gained during 2009 influenza pandemic indicates that International Influenza Control System is very efficient, however more flexibility is required in application of treatment and prophylaxis procedures with new influenza strains. Applied methods of control should mostly depend on the virulence of pandemic strain. PMID:22390048

  14. In Vitro Antiviral Activity of Favipiravir (T-705) against Drug-Resistant Influenza and 2009 A(H1N1) Viruses▿

    Sleeman, Katrina; Mishin, Vasiliy P.; Deyde, Varough M.; Furuta, Yousuke; Klimov, Alexander I; Larisa V Gubareva


    Favipiravir (T-705) has previously been shown to have a potent antiviral effect against influenza virus and some other RNA viruses in both cell culture and in animal models. Currently, favipiravir is undergoing clinical evaluation for the treatment of influenza A and B virus infections. In this study, favipiravir was evaluated in vitro for its ability to inhibit the replication of a representative panel of seasonal influenza viruses, the 2009 A(H1N1) strains, and animal viruses with pandemic ...

  15. Theoretical studies on the susceptibility of oseltamivir against variants of 2009 A/H1N1 influenza neuraminidase.

    Li, Lin; Li, Youyong; Zhang, Liling; Hou, Tingjun


    The outbreak and high speed global spread of the new strain of influenza A/H1N1 virus in 2009 posed a serious threat to global health. It is more likely that drug-resistant influenza strains will arise after the extensive use of anti-influenza drugs. Consequently, the identification of the potential resistant sites for drugs in advance and the understanding of the corresponding molecular mechanisms that cause drug resistance are quite important in the design of new drug candidates with better potency to combat drug resistance. Here, we performed molecular simulations to evaluate the potency of oseltamivir to combat drug resistance caused by the mutations in 2009 A/H1N1 neuraminidase (NA). We examined three representative drug-resistant mutations in NA, consisting of H274Y, N294S, and Y252H. First, a theoretical structure of A/H1N1 NA in complex with oseltamivir was constructed using homology modeling. Then, molecular dynamics (MD) simulations, molecular mechanics/Poisson-Boltzmann surface area (MM/PBSA) calculations, and MM/GBSA free energy decomposition were used to characterize the binding of oseltamivir with the wild type (WT) and three mutated NAs. Our predictions show that N294S and H274Y, two popular drug-resistant mutations in different variants of NA, still cause significant resistance to oseltamivir. However, the Y252H mutation does not impair the interactions between oseltamivir and A/H1N1 NA. An examination of individual energy components shows that the loss of polar interactions is the key source for the resistance of the studied mutations to oseltamivir. Moreover, free energy decomposition analysis and structural analysis reveal that the N294S or H274Y mutation triggers the large-scale conformational changes of the binding pocket and then impairs the affinity of oseltamivir. We expect that our results will be useful for the rational design of NA inhibitors with high potency against drug-resistant A/H1N1 mutants. PMID:22998323

  16. Clinical features, complications and mortality in critically ill patients with 2009 influenza A(H1N1) in Sfax,Tunisia

    Damak, Hassen; Chtara, Kamilia; Bahloul, Mabrouk; Kallel, Hatem; Chaari, Anis; Ksibi, Hichem; Chaari, Adel; Chelly, Hedi; Rekik, Noureddine; Ben Hamida, Chokri; Bouaziz, Mounir


    Please cite this paper as: Damak et al.(2011) Clinical features, complications and mortality in critically ill patients with 2009 influenza A(H1N1) in Sfax,Tunisia. Influenza and Other Respiratory Viruses 5(4), 230–240 Purpose  Africa, as the rest of the world, was touched by the 2009 pandemic influenza A(H1N1). In the literature, a few publications covering this subject emerged from this continent. We prospectively describe baseline characteristics, treatment and outcomes of consecutive crit...

  17. Monitoring pandemic influenza A(H1N1) vaccination coverage in Germany 2009/10

    Walter, Dietmar; Böhmer, Merle; An der Heiden, Matthias; Reiter, Sabine; Krause, Gérard; Wichmann, Ole


    To monitor pandemic influenza A(H1N1) vaccine uptake during the vaccination campaign in Germany 2009/10, thirteen consecutive cross-sectional telephone-surveys were performed between November 2009 and April 2010. In total 13,010 household-interviews were conducted. Vaccination coverage in persons >14 years of age remained low, both in the general population (8.1%; 95%CI: 7.4–8.8) and in specific target groups such as healthcare workers and individuals with underlying chronic diseases (12.8%; ...

  18. The progress of research on influenza A(H1N1)%甲型H1N1流感的研究进展

    雷晓燕; 孙永红


    Influenza A(H1N1)virus is a re-mixed strains of human influenza virus genes,avian influenza virus gene and swine influenza virus gene.Influenza A(H1N1)pandemic influenza has spread around the world,which has drawn worldwide attention.In order to early discovery,early diagnosis,early treatment and effective prevention of Influenza A(H1N1),we describe the characteristics of linfluenza A(H1N1)virus,epidemiology,pathogenesis,clinical manifestations,laboratory examination and effective treatment and preventive measures.%甲型H1N1流感病毒是人流感病毒基因、禽流感病毒基因和猪流感病毒基因混合的重配株,其造成的疫情来势凶猛,引起世界各国的广泛关注.为了早发现、早诊断、早治疗及有效地预防甲型H1N1流感,本文综述了甲型H1N1流感病毒的特点、流行病学、致人发病的机制、甲型H1N1流感患者的临床表现、实验室检查及有效的治疗和预防措施.

  19. Effectiveness of the influenza a(H1N1)PDM09 vaccine in adults recommended for annual influenza vaccination : A case-control study

    Gefenaite, Giedre; Tacken, Margot; Bos, Jens; Stirbu-Wagner, Irina; Korevaar, Joke C.; Stolk, Ronald P.; Wolters, Bert; Bijl, Marc; Postma, Maarten J.; Wilschut, Jan; Nichol, Kristin L.; Hak, Eelko


    Background: Because of variability in published A(H1N1)pdm09 influenza vaccine effectiveness estimates, we aimed to assess the effectiveness of MF59-adjuvanted A(H1N1)pdm09 vaccine in a matched case-control study. Objectives: We aimed to assess the effectiveness of MF59- adjuvanted A(H1N1)pdm09 infl

  20. Socioeconomic factors influencing hospitalized patients with pneumonia due to influenza A(H1N1pdm09 in Mexico.

    Toshie Manabe

    Full Text Available BACKGROUND: In addition to clinical aspects and pathogen characteristics, people's health-related behavior and socioeconomic conditions can affect the occurrence and severity of diseases including influenza A(H1N1pdm09. METHODOLOGY AND PRINCIPAL FINDINGS: A face-to-face interview survey was conducted in a hospital in Mexico City at the time of follow-up consultation for hospitalized patients with pneumonia due to influenza virus infection. In all, 302 subjects were enrolled and divided into two groups based on the period of hospitalization. Among them, 211 tested positive for influenza A(H1N1pdm09 virus by real-time reverse-transcriptase-polymerase-chain-reaction during the pandemic period (Group-pdm and 91 tested positive for influenza A virus in the post-pandemic period (Group-post. All subjects were treated with oseltamivir. Data on the demographic characteristics, socioeconomic status, living environment, and information relating to A(H1N1pdm09, and related clinical data were compared between subjects in Group-pdm and those in Group-post. The ability of household income to pay for utilities, food, and health care services as well as housing quality in terms of construction materials and number of rooms revealed a significant difference: Group-post had lower socioeconomic status than Group-pdm. Group-post had lower availability of information regarding H1N1 influenza than Group-pdm. These results indicate that subjects in Group-post had difficulty receiving necessary information relating to influenza and were more likely to be impoverished than those in Group-pdm. Possible factors influencing time to seeking health care were number of household rooms, having received information on the necessity of quick access to health care, and house construction materials. CONCLUSIONS: Health-care-seeking behavior, poverty level, and the distribution of information affect the occurrence and severity of pneumonia due to H1N1 virus from a socioeconomic

  1. Estimating time to onset of swine influenza symptoms after initial novel A(H1N1v) viral infection.

    Tom, B D M; Van Hoek, A J; Pebody, R; McMenamin, J; Robertson, C; Catchpole, M; De Angelis, D


    Characterization of the incubation time from infection to onset is important for understanding the natural history of infectious diseases. Attempts to estimate the incubation time distribution for novel A(H1N1v) have been, up to now, based on limited data or peculiar samples. We characterized this distribution for a generic group of symptomatic cases using laboratory-confirmed swine influenza case-information. Estimates of the incubation distribution for the pandemic influenza were derived through parametric time-to-event analyses of data on onset of symptoms and exposure dates, accounting for interval censoring. We estimated a mean of about 1·6-1·7 days with a standard deviation of 2 days for the incubation time distribution in those who became symptomatic after infection with the A(H1N1v) virus strain. Separate analyses for the <15 years and ≥ 15 years age groups showed a significant (P<0·02) difference with a longer mean incubation time in the older age group. PMID:21087539

  2. Infant Respiratory Outcomes Associated with Prenatal Exposure to Maternal 2009 A/H1N1 Influenza Vaccination

    Fell, Deshayne B.; Wilson, Kumanan; Ducharme, Robin; Hawken, Steven; Sprague, Ann E.; Kwong, Jeffrey C.; Smith, Graeme; Wen, Shi Wu; Walker, Mark C.


    Background Infants are at high risk for influenza illness, but are ineligible for vaccination before 6 months. Transfer of maternal antibodies to the fetus has been demonstrated for 2009 A/H1N1 pandemic vaccines; however, clinical effectiveness is unknown. Our objective was to evaluate the association between 2009 A/H1N1 pandemic vaccination during pregnancy and rates of infant influenza and pneumonia. Methods We linked a population-based birth cohort to administrative databases to measure rates of influenza and pneumonia diagnosed during ambulatory physician visits, hospitalizations and emergency department visits during one year of follow-up. We estimated incidence rate ratios and 95% confidence intervals (95% CI) using Poisson regression, comparing infants born to A/H1N1-vaccinated women (vaccine-exposed infants) with unexposed infants, adjusted for confounding using high-dimensional propensity scores. Results Among 117,335 infants in the study, 36,033 (31%) were born to A/H1N1-vaccinated women. Crude rates of influenza during the pandemic (per 100,000 infant-days) for vaccine-exposed and unexposed infants were similar (2.19, 95% CI: 1.27–3.76 and 3.60, 95% CI: 2.51–5.14, respectively), as were crude rates of influenza and pneumonia combined. We did not observe any significant differences in rates of study outcomes between study groups during the second wave of the 2009 A/H1N1 pandemic, nor during any post-pandemic time period. Conclusion We observed no difference in rates of study outcomes among infants born to A/H1N1-vaccinated mothers relative to unexposed infants born during the second A/H1N1 pandemic wave; however, due to late availability of the pandemic vaccine, the available follow-up time during the pandemic time period was very limited. PMID:27486858

  3. Changes in severity of 2009 pandemic A/H1N1 influenza in England: a Bayesian evidence synthesis

    Presanis, A. M.; Pebody, R. G.; Paterson, B J; Tom, B D M; Birrell, P. J.; Charlett, A.; Lipsitch, Marc; Angelis, D. D.


    Objective: To assess the impact of the 2009 A/H1N1 influenza pandemic in England during the two waves of activity up to end of February 2010 by estimating the probabilities of cases leading to severe events and the proportion of the population infected. Design: A Bayesian evidence synthesis of all available relevant surveillance data in England to estimate severity of the pandemic. Data sources: All available surveillance systems relevant to the pandemic 2009 A/H1N1 influenza outbreak in Engl...

  4. Timeliness of contact tracing among flight passengers for influenza A/H1N1 2009

    Swaan Corien M


    Full Text Available Abstract Background During the initial containment phase of influenza A/H1N1 2009, close contacts of cases were traced to provide antiviral prophylaxis within 48 h after exposure and to alert them on signs of disease for early diagnosis and treatment. Passengers seated on the same row, two rows in front or behind a patient infectious for influenza, during a flight of ≥ 4 h were considered close contacts. This study evaluates the timeliness of flight-contact tracing (CT as performed following national and international CT requests addressed to the Center of Infectious Disease Control (CIb/RIVM, and implemented by the Municipal Health Services of Schiphol Airport. Methods Elapsed days between date of flight arrival and the date passenger lists became available (contact details identified - CI was used as proxy for timeliness of CT. In a retrospective study, dates of flight arrival, onset of illness, laboratory diagnosis, CT request and identification of contacts details through passenger lists, following CT requests to the RIVM for flights landed at Schiphol Airport were collected and analyzed. Results 24 requests for CT were identified. Three of these were declined as over 4 days had elapsed since flight arrival. In 17 out of 21 requests, contact details were obtained within 7 days after arrival (81%. The average delay between arrival and CI was 3,9 days (range 2-7, mainly caused by delay in diagnosis of the index patient after arrival (2,6 days. In four flights (19%, contacts were not identified or only after > 7 days. CI involving Dutch airlines was faster than non-Dutch airlines (P Conclusion CT for influenza A/H1N1 2009 among flight passengers was not successful for timely provision of prophylaxis. CT had little additional value for alerting passengers for disease symptoms, as this information already was provided during and after the flight. Public health authorities should take into account patient delays in seeking medical advise and

  5. Influenza A(H1N1)pdm09 vaccination policies and coverage in Europe.

    Mereckiene, J


    In August 2010 the Vaccine European New Integrated Collaboration Effort (VENICE) project conducted a survey to collect information on influenza A(H1N1)pdm09 vaccination policies and vaccination coverage in the European Union (EU), Norway and Iceland. Of 29 responding countries, 26 organised national pandemic influenza vaccination and one country had recommendations for vaccination but did not have a specific programme. Of the 27 countries with vaccine recommendations, all recommended it for healthcare workers and pregnant women. Twelve countries recommended vaccine for all ages. Six and three countries had recommendations for specific age groups in children and in adults, countries for specific adult age groups. Most countries recommended vaccine for those in new risk groups identified early in the pandemic such as morbid obese and people with neurologic diseases. Two thirds of countries started their vaccination campaigns within a four week period after week 40\\/2009. The reported vaccination coverage varied between countries from 0.4% to 59% for the entire population (22 countries); 3% to 68% for healthcare workers (13 countries); 0% to 58% for pregnant women (12 countries); 0.2% to 74% for children (12 countries). Most countries identified similar target groups for pandemic vaccine, but substantial variability in vaccination coverage was seen. The recommendations were in accordance with policy advice from the EU Health Security Committee and the World Health Organization.

  6. Analysis of oseltamivir-resistant H275Y mutation in a novel A/H1N1 influenza virus strain%一株新型甲型H1N1流感病毒H275Y的奥司他韦耐药变异分析

    苏彤; 李淑华; 鹿文英; 韩磊; 韩一芳; 曹广文


    Objective To elucidate the genetic characteristics and variations of glycosylation sites of neuraminidase (NA) gene of the novel A/H1N1 influenza pandemic virus in 2009. Methods The sequences of NA gene of 110 A/H1N1 influenza virus strains isolated at different time and locations were downloaded from NCBI database. MEGA4.0 software and NJ method were used for nucleotide sequence alignment, coding protein sequence alignment and the phylogenetic tree construction. Results The NA gene of the novel A/H1N1 influenza virus strains isolated from different areas in 2009 shared an extremely high homology of 99. 5%-100%, but it was different from that of A/human/H1N1 influenza virus. The novel A/H1N1 influenza virus strains and Europe A/swine/HlNl influenza virus strains shared a high homology of 89. 6% - 92. 9%, with similar glycosylation sites at 50, 58, 63, 68, 88, 146, 235 and 386. Moreover, the homology of NA gene between the novel A/H1N1 influenza virus and A/chicken/H5N1 influenza virus amounted to 83. 6% -85. 3%. Amino acid residues at the enzyme active sites of the NA were strictly conservative in most novel A/H1N1 influenza virus strains, still manifesting as R118, D151, R152, R225, E277, R293, R368, Y402, E119, R156, W179, S180, D199, 1223, E228, H275, E278, N295 and E425. Four strains isolated from Denmark, Japan, and HongKong and Hunan province showed a H275Y mutatioa The NA gene of the novel A/H1N1 influenza virus might originate from Europe A/swine/HlNl influenza virus, and had genetic relationship with A/ chicken/H5N1 influenza virus. Conclusions The novel A/H1N1 influenza pandemic virus in 2009 might be a reassorted virus rather than the result of gradual evolution of A/human/HlNl influenza virus. A novel A/H1N1 influenza virus strain isolated from Hunan has a H275Y mutation which might be oseltamivir resistant.%目的 探讨2009年新型甲型H1N1流感病毒神经氨酸酶(NA)基因的进化规律,分析NA蛋白酶活性位点以及糖基

  7. Pandemic A/H1N1v influenza 2009 in hospitalized children: a multicenter Belgian survey

    Blumental Sophie


    Full Text Available Abstract Background During the 2009 influenza A/H1N1v pandemic, children were identified as a specific "at risk" group. We conducted a multicentric study to describe pattern of influenza A/H1N1v infection among hospitalized children in Brussels, Belgium. Methods From July 1, 2009, to January 31, 2010, we collected epidemiological and clinical data of all proven (positive H1N1v PCR and probable (positive influenza A antigen or culture pediatric cases of influenza A/H1N1v infections, hospitalized in four tertiary centers. Results During the epidemic period, an excess of 18% of pediatric outpatients and emergency department visits was registered. 215 children were hospitalized with proven/probable influenza A/H1N1v infection. Median age was 31 months. 47% had ≥ 1 comorbid conditions. Febrile respiratory illness was the most common presentation. 36% presented with initial gastrointestinal symptoms and 10% with neurological manifestations. 34% had pneumonia. Only 24% of the patients received oseltamivir but 57% received antibiotics. 10% of children were admitted to PICU, seven of whom with ARDS. Case fatality-rate was 5/215 (2%, concerning only children suffering from chronic neurological disorders. Children over 2 years of age showed a higher propensity to be admitted to PICU (16% vs 1%, p = 0.002 and a higher mortality rate (4% vs 0%, p = 0.06. Infants less than 3 months old showed a milder course of infection, with few respiratory and neurological complications. Conclusion Although influenza A/H1N1v infections were generally self-limited, pediatric burden of disease was significant. Compared to other countries experiencing different health care systems, our Belgian cohort was younger and received less frequently antiviral therapy; disease course and mortality were however similar.

  8. Toll-like receptor 3 gene polymorphisms and severity of pandemic A/H1N1/2009 influenza in otherwise healthy children

    Esposito Susanna


    Full Text Available Abstract Background Toll-like receptors (TLRs form an essential part of the innate immune system, which plays a fundamental role in rapidly and effectively controlling infections and initiating adaptive immunity. There are no published data concerning the importance of polymorphisms of TLRs in conditioning susceptibility to influenza or the severity of the disease. The aim of this study was to evaluate whether selected polymorphisms of TLR2, TLR3 and TLR4 influence the incidence and clinical picture of pandemic A/H1N1/2009 influenza. Results The study involved 272 healthy children attending our Emergency Room for influenza-like illness (ILI, including 51 (18.8% with pandemic A/H1N1/2009 influenza as revealed by real-time polymerase chain reaction, and 164 healthy controls examined after minor surgery. Genomic DNA was extracted from whole blood samples and five single-nucleotide polymorphisms (SNPs were studied: TLR2 rs5743708, TLR3 rs5743313, TLR3 rs5743315, TLR4 rs4986790 and TLR4 rs4986791. The TLR3 rs5743313/CT polymorphism was found in all of the children with pneumonia and influenza infection, but in a significantly smaller number of those with A/H1N1/2009 influenza without pneumonia ( Conclusions There is a close relationship between the presence of TLR3 rs5743313/CT and an increased risk of pneumonia in children infected by the pandemic A/H1N1/2009 influenza virus.

  9. Healthcare workers as parents: attitudes toward vaccinating their children against pandemic influenza A/H1N1

    Torun Fuat; Torun Sebahat D; Catak Binali


    Abstract Background Both the health care workers (HCWs) and children are target groups for pandemic influenza vaccination. The coverage of the target populations is an important determinant for impact of mass vaccination. The objective of this study is to determine the attitudes of HCWs as parents, toward vaccinating their children with pandemic influenza A/H1N1 vaccine. Methods A cross-sectional questionnaire survey was conducted with health care workers (HCWs) in a public hospital during De...

  10. Bayesian modeling to unmask and predict influenza A/H1N1pdm dynamics in London

    Birrell, Paul J.; Ketsetzis, Georgios; Gay, Nigel J.; Cooper, Ben S.; Presanis, Anne M.; Harris, Ross J.; Charlett, André; Zhang, Xu-Sheng; Peter J White; Pebody, Richard G.; De Angelis, Daniela


    The tracking and projection of emerging epidemics is hindered by the disconnect between apparent epidemic dynamics, discernible from noisy and incomplete surveillance data, and the underlying, imperfectly observed, system. Behavior changes compound this, altering both true dynamics and reporting patterns, particularly for diseases with nonspecific symptoms, such as influenza. We disentangle these effects to unravel the hidden dynamics of the 2009 influenza A/H1N1pdm pandemic in London, where ...

  11. Enhanced Pneumonia and Proinflammatory Cytokine Response in Pigs Challenged with Pandemic 2009 A/H1N1 Influenza Virus Following Vaccination with an Inactivated delta-Cluster H1N2 Virus

    Endemic strains of swine influenza A virus (IAV) in North America consist of the subtypes H1N1, H1N2, and H3N2. These circulating strains contain the triple reassortant internal gene (TRIG) cassette resulting from incorporation of genes from swine, avian, and human IAV’s. Genetic drift and reassortm...

  12. Seroepidemiologic Effects of Influenza A(H1N1)pdm09 in Australia, New Zealand, and Singapore

    Trauer, James M.; Bandaranayake, Don; Booy, Robert; Chen, Mark I; Cretikos, Michelle; Dowse, Gary K.; Dwyer, Dominic E; Greenberg, Michael E.; Huang, Q. Sue; Khandaker, Gulam; Kok, Jen; Laurie, Karen L.; Lee, Vernon J.; McVernon, Jodie; Walter, Scott


    To estimate population attack rates of influenza A(H1N1)pdm2009 in the Southern Hemisphere during June–August 2009, we conducted several serologic studies. We pooled individual-level data from studies using hemagglutination inhibition assays performed in Australia, New Zealand, and Singapore. We determined seropositive proportions (titer >40) for each study region by age-group and sex in pre- and postpandemic phases, as defined by jurisdictional notification data. After exclusions, the pooled...

  13. Emerging influenza A/H1N1: challenges and development

    Mishra N


    Human population suffered to four major influenza pandemics in the past by influenza virus in the form of either bird flu or swine flu. The virus has immense capability to diverse as it is capable in antigenic shift, antigenic drift and reassortment due to its fragmented RNA genome. The severity of previous pandemics suggests that severity in human population is directly proportional to the degree of divergence in hemagglutinin (HA) and neuraminidase (NA) genes and so the virus is named as Hn...

  14. Study on the genomic sequences and molecular characteristics of influenza A(H1N1) virus%甲型H1N1流感病毒基因组序列分析及其特性研究

    沃恩康; 吴海波; 王怡婷; 汪一帆; 王闻哲; 李颖; 郭潮潭


    目的 分析甲型H1N1流感病毒的基因组序列特征,阐明该毒株的遗传变异及分子特性.方法 GenBank中获取流感病毒全序列,对各段基因与已知序列进行分析比较,绘制进化树,并分析和预测甲型毒株的致病性、药物敏感性和现有疫苗的预防保护作用.结果 甲型H1N1病毒的HA、PB2、PB1、PA、NP、NS基因与美国本土的猪流感病毒序列具有高度同源性,NA和M基因具有典型的欧亚株系猪流感病毒特征.该病毒具有人传人的分子基础,HA上HA1和HA2裂解位点序列为PSIQSR↓+GLFGAI,尚不具备高致病性流感病毒的特征.病毒对金刚烷胺类药物耐药,而对达菲和扎那米韦敏感.HA片段5个抗原决定区氨基酸序列与人用流感疫苗具有较大差异,推测现有疫苗对预防本次疫情基本无效.结论 甲型H1N1是一种北美和欧亚两种猪流感病毒的混合体,开发针对本病毒的流感疫苗有助于进一步控制疫情蔓延.%Objective To analyse the genome of influenza A (H1N1) vires so as to elucidate its molecular characteristics and evolution status. Methods DNA sequences of the influenza viruses were collected from NCBI, and compared with the genomes of referenced intluenza viruses. The phylogenetic trees were constructed by the neighbor-joining method, and the pathogenicity, drug susceptibility and vaccine protection were analyzed. Results Phyiogenetic analysis showed that the genes encoding HA, PB2, PBI, PA, NP, and NS protein were most closely related to those influenza A viruses circulating in swine populations in North America. NA and M gene belonged to Eurasia lineages swine influenza vires. The amino acid sequence of the cleavage site between HA1 and HA2 was PARSSR ↓ GLFGAI with the typical characteristics of the low pathogenic influenza virus. Influenza A(H1N1) virus can spread from person-to-person. It is sensitive to oseltamivir and zanamivir but resistant to amantadine and remantadine. The current

  15. Epidemiological characteristics of the influenza A(H1N1 2009 pandemic in the Western Pacific Region

    Lisa McCallum


    Full Text Available The first laboratory-confirmed cases of infection with pandemic influenza A(H1N1 2009 in the Western Pacific Region were reported on 28 April 2009. By 11 June 2009, the day the pandemic was declared by the World Health Organization, nine Western Pacific Region countries and areas had reported laboratory-confirmed pandemic influenza A(H1N1 2009 cases. From April 2009 to July 2010, more than 250 000 cases and 1800 deaths from laboratory-confirmed pandemic influenza A(H1N1 2009 were reported from 34 countries and areas in the Region. By age group region-wide, 8.6%, 41.9%, 48.3%, and 1.2% of cases were in the < 5 years, 5–14 years, 15–64 years, and 65+ years age groups, respectively; the overall crude case fatality ratio in the Western Pacific Region was 0.5%. The pandemic demonstrated that region-wide disease reporting was possible. Countries and areas of the Western Pacific Region should take this opportunity to strengthen the systems established during the pandemic to develop routine disease reporting.

  16. Early assessment of anxiety and behavioral response to novel swine-origin influenza A(H1N1.

    James Holland Jones

    Full Text Available BACKGROUND: Since late April, 2009, a novel influenza virus A (H1N1, generally referred to as the "swine flu," has spread around the globe and infected hundreds of thousands of people. During the first few days after the initial outbreak in Mexico, extensive media coverage together with a high degree of uncertainty about the transmissibility and mortality rate associated with the virus caused widespread concern in the population. The spread of an infectious disease can be strongly influenced by behavioral changes (e.g., social distancing during the early phase of an epidemic, but data on risk perception and behavioral response to a novel virus is usually collected with a substantial delay or after an epidemic has run its course. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the results from an online survey that gathered data (n = 6,249 about risk perception of the Influenza A(H1N1 outbreak during the first few days of widespread media coverage (April 28-May 5, 2009. We find that after an initially high level of concern, levels of anxiety waned along with the perception of the virus as an immediate threat. Overall, our data provide evidence that emotional status mediates behavioral response. Intriguingly, principal component analysis revealed strong clustering of anxiety about swine flu, bird flu and terrorism. All three of these threats receive a great deal of media attention and their fundamental uncertainty is likely to generate an inordinate amount of fear vis-a-vis their actual threat. CONCLUSIONS/SIGNIFICANCE: Our results suggest that respondents' behavior varies in predictable ways. Of particular interest, we find that affective variables, such as self-reported anxiety over the epidemic, mediate the likelihood that respondents will engage in protective behavior. Understanding how protective behavior such as social distancing varies and the specific factors that mediate it may help with the design of epidemic control strategies.

  17. Emerging influenza A/H1N1: challenges and development

    Mishra N


    Full Text Available Human population suffered to four major influenza pandemics in the past by influenza virus in the form of either bird flu or swine flu. The virus has immense capability to diverse as it is capable in antigenic shift, antigenic drift and reassortment due to its fragmented RNA genome. The severity of previous pandemics suggests that severity in human population is directly proportional to the degree of divergence in hemagglutinin (HA and neuraminidase (NA genes and so the virus is named as HnNn (H1N1, H5N1, etc. Till date no treatment (vaccines and drugs is available against influenza virus infection. Therefore, evolution of new strains, lack of herd immunity, high divergence rate, resistance against antiviral, co-infection with different influenza strains and replication in multiple hosts might help the present virus to develop in super-virus with a potential health threat to man-kind. To tackle the issue, there is a need for a joint venture among government health department, researchers, clinicians, ecologists and general public for future preparedness to combat future influenza pandemics.

  18. Influenza vaccination in the Americas: Progress and challenges after the 2009 A(H1N1) influenza pandemic

    Ropero-Álvarez, Alba María; El Omeiri, Nathalie; Kurtis, Hannah Jane; Danovaro-Holliday, M. Carolina; Ruiz-Matus, Cuauhtémoc


    ABSTRACT Background: There has been considerable uptake of seasonal influenza vaccines in the Americas compared to other regions. We describe the current influenza vaccination target groups, recent progress in vaccine uptake and in generating evidence on influenza seasonality and vaccine effectiveness for immunization programs. We also discuss persistent challenges, 5 years after the A(H1N1) 2009 influenza pandemic. Methods: We compiled and summarized data annually reported by countries to the Pan American Health Organization/World Health Organization (PAHO/WHO) through the WHO/UNICEF joint report form on immunization, information obtained through PAHO's Revolving Fund for Vaccine Procurement and communications with managers of national Expanded Programs on Immunization (EPI). Results: Since 2008, 25 countries/territories in the Americas have introduced new target groups for vaccination or expanded the age ranges of existing target groups. As of 2014, 40 (89%) out of 45 countries/territories have policies established for seasonal influenza vaccination. Currently, 29 (64%) countries/territories target pregnant women for vaccination, the highest priority group according to WHO´s Stategic Advisory Group of Experts and PAHO/WHO's Technical Advisory Group on Vaccine-preventable Diseases, compared to only 7 (16%) in 2008. Among 23 countries reporting coverage data, on average, 75% of adults ≥60 years, 45% of children aged 6–23 months, 32% of children aged 5–2 years, 59% of pregnant women, 78% of healthcare workers, and 90% of individuals with chronic conditions were vaccinated during the 2013–14 Northern Hemisphere or 2014 Southern Hemisphere influenza vaccination activities. Difficulties however persist in the estimation of vaccination coverage, especially for pregnant women and persons with chronic conditions. Since 2007, 6 tropical countries have changed their vaccine formulation from the Northern to the Southern Hemisphere formulation and the timing of

  19. A(H1N1)Influenza Pneumonia with Acute Disseminated Encephalomyelitis: A Case Report



    @@ INTRODUCTION A 56-year-old Chinese female patient with A (H1N1) influenza pneumonia accompanied by acute disseminated encephalomyelitis (ADEM) of the Central Nervous System (CNS) is described in this article. The patient had typical clinical manifestation,and the diagnosis was reached after MRI and other examinations. From this case, we can conclude that the virus ofA (H1N1) influenza can infect CNS, and we should pay more attention to patients of A (H1N1)influenza pneumonia with neurological complications.

  20. Epidemia de influenza A(H1N1 en la Argentina: Experiencia del Hospital Nacional Profesor Alejandro Posadas Influenza A(H1N1 epidemic in Argentina: Experience in a National General Hospital (Hospital Nacional Profesor Alejandro Posadas


    Full Text Available Se describe la preparación y la atención médica durante la epidemia de influenza A(H1N1 (junio 2009 en un hospital general de agudos, público, de alta complejidad; con diagnóstico de laboratorio, internación general y cuidados intensivos (UCI. Se elaboró un plan para aumentar la capacidad asistencial, reasignar recursos y garantizar la bioseguridad. La consulta fue 7.1 ± 3.8 veces mayor que en 2006-2008. La detección de casos de A(H1N1 fue confirmada por PCR-RT en 186/486 (38.3% pacientes internados y en 56/176 (31.8% ambulatorios. Internados: mediana de edad 20 años; 75% menores de 45 y 32.3% menores de 15. Mortalidad global: 6.8%; 9.1% en los positivos. Adultos: recepción en un área de atención ambulatoria, internación (aislamiento y ventilación mecánica. Sala general: ingresaron 110 pacientes (5 veces más que 1999-2006 con saturación de oxígeno The preparation and medical care during the influenza A(H1N1 outbreak (June 2009 in a high complexity level, public, general hospital with laboratory diagnosis, general and intensive care (ICU hospitalization is described. A plan was designed to increase the hospital's surge capacity, reallocate resources and guarantee bio-safety. The number of consultations was 7.1 ± 3.8 times higher than during June 2006-2008. Detection of A(H1N1 cases were confirmed by PCR-RT in 186/486 (38.3% in-patients and 56/176 (31.8% out-patients. Median age among in-patients was 20 years; 75% < 45 and 32.3% < 15. Global mortality: 6.8%; 9.1% among confirmed cases. Adults were directed to a reception area of out-patient care, hospitalization (isolation and mechanical ventilation. General ward: 110 patients with oxygen saturation < 96% and/or risk factors (65.5% had asthma, chronic obstructive pulmonary disease, obesity, pregnancy or other were admitted (5 times more than in 1999-2006. Chest X-ray showed lung infiltrates and/or lung consolidation in 97.3%. Severe hypoxemia: 43.5%. There were no significant

  1. Healthcare workers as parents: attitudes toward vaccinating their children against pandemic influenza A/H1N1

    Torun Fuat


    Full Text Available Abstract Background Both the health care workers (HCWs and children are target groups for pandemic influenza vaccination. The coverage of the target populations is an important determinant for impact of mass vaccination. The objective of this study is to determine the attitudes of HCWs as parents, toward vaccinating their children with pandemic influenza A/H1N1 vaccine. Methods A cross-sectional questionnaire survey was conducted with health care workers (HCWs in a public hospital during December 2009 in Istanbul. All persons employed in the hospital with or without a health-care occupation are accepted as HCW. The HCWs who are parents of children 6 months to 18 years of age were included in the study. Pearson's chi-square test and logistic regression analysis was applied for the statistical analyses. Results A total of 389 HCWs who were parents of children aged 6 months-18 years participated study. Among all participants 27.0% (n = 105 reported that themselves had been vaccinated against pandemic influenza A/H1N1. Two third (66.1% of the parents answered that they will not vaccinate their children, 21.1% already vaccinated and 12.9% were still undecided. Concern about side effect was most reported reason among who had been not vaccinated their children and among undecided parents. The second reason for refusing the pandemic vaccine was concerns efficacy of the vaccine. Media was the only source of information about pandemic influenza in nearly one third of HCWs. Agreement with vaccine safety, self receipt of pandemic influenza A/H1N1 vaccine, and trust in Ministry of Health were found to be associated with the positive attitude toward vaccinating their children against pandemic influenza A/H1N1. Conclusions Persuading parents to accept a new vaccine seems not be easy even if they are HCWs. In order to overcome the barriers among HCWs related to pandemic vaccines, determination of their misinformation, attitudes and behaviors regarding the

  2. Influenza risk management: lessons learned from an A(H1N1 pdm09 outbreak investigation in an operational military setting.

    Margaret Farrell

    Full Text Available BACKGROUND: At the onset of an influenza pandemic, when the severity of a novel strain is still undetermined and there is a threat of introduction into a new environment, e.g., via the deployment of military troops, sensitive screening criteria and conservative isolation practices are generally recommended. OBJECTIVES: In response to elevated rates of influenza-like illness among U.S. military base camps in Kuwait, U.S. Naval Medical Research Unit No. 3 partnered with local U.S. Army medical units to conduct an A(H1N1 pdm09 outbreak investigation. PATIENTS/METHODS: Initial clinical data and nasal specimens were collected via the existent passive surveillance system and active surveillance was conducted using a modified version of the World Health Organization/U.S. Centers for Disease Control and Prevention influenza-like illness case definition [fever (T > 100.5˚F/38˚C in addition to cough and/or sore throat in the previous 72 hours] as the screening criteria. Samples were tested via real-time reverse-transcription PCR and sequenced for comparison to global A(H1N1 pdm09 viruses from the same time period. RESULTS: The screening criteria used in Kuwait proved insensitive, capturing only 16% of A(H1N1 pdm09-positive individuals. While still not ideal, using cough as the sole screening criteria would have increased sensitivity to 73%. CONCLUSIONS: The results of and lessons learned from this outbreak investigation suggest that pandemic influenza risk management should be a dynamic process (as information becomes available regarding true attack rates and associated mortality, screening and isolation criteria should be re-evaluated and revised as appropriate, and that military operational environments present unique challenges to influenza surveillance.

  3. Multidrug resistant 2009 A/H1N1 influenza clinical isolate with a neuraminidase I223R mutation retains its virulence and transmissibility in ferrets.

    Erhard van der Vries


    Full Text Available Only two classes of antiviral drugs, neuraminidase inhibitors and adamantanes, are approved for prophylaxis and therapy against influenza virus infections. A major concern is that influenza virus becomes resistant to these antiviral drugs and spreads in the human population. The 2009 pandemic A/H1N1 influenza virus is naturally resistant to adamantanes. Recently a novel neuraminidase I223R mutation was identified in an A/H1N1 virus showing cross-resistance to the neuraminidase inhibitors oseltamivir, zanamivir and peramivir. However, the ability of this virus to cause disease and spread in the human population is unknown. Therefore, this clinical isolate (NL/2631-R223 was compared with a well-characterized reference virus (NL/602. In vitro experiments showed that NL/2631-I223R replicated as well as NL/602 in MDCK cells. In a ferret pathogenesis model, body weight loss was similar in animals inoculated with NL/2631-R223 or NL/602. In addition, pulmonary lesions were similar at day 4 post inoculation. However, at day 7 post inoculation, NL/2631-R223 caused milder pulmonary lesions and degree of alveolitis than NL/602. This indicated that the mutant virus was less pathogenic. Both NL/2631-R223 and a recombinant virus with a single I223R change (recNL/602-I223R, transmitted among ferrets by aerosols, despite observed attenuation of recNL/602-I223R in vitro. In conclusion, the I223R mutated virus isolate has comparable replicative ability and transmissibility, but lower pathogenicity than the reference virus based on these in vivo studies. This implies that the 2009 pandemic influenza A/H1N1 virus subtype with an isoleucine to arginine change at position 223 in the neuraminidase has the potential to spread in the human population. It is important to be vigilant for this mutation in influenza surveillance and to continue efforts to increase the arsenal of antiviral drugs to combat influenza.

  4. Psychological response of family members of patients hospitalised for influenza A/H1N1 in Oaxaca, Mexico

    Mayoral-García Maurilio


    Full Text Available Abstract Background The A/H1N1 pandemic originated in Mexico in April 2009, amid high uncertainty, social and economic disruption, and media reports of panic. The aim of this research project was to evaluate the psychological response of family primary caregivers of patients hospitalised in the Intensive Care Unit (ICU with suspected influenza A/H1N1 to establish whether there was empirical evidence of high adverse psychological response, and to identify risk factors for such a response. If such evidence was found, a secondary aim was to develop a specific early intervention of psychological support for these individuals, to reduce distress and possibly lessen the likelihood of post-traumatic stress disorder (PTSD in the longer term. Methods Psychological assessment questionnaires were administered to the family primary caregivers of patients hospitalised in the ICU in the General Hospital of Zone 1 of the Mexican Institute for Social Security (IMSS, Oaxaca, Mexico with suspected influenza A/H1N1, during the month of November 2009. The main outcome measures were ratings of reported perceived stress (PSS-10, depression (CES-D, and death anxiety (DAQ. Data were subjected to simple and multiple linear regression analysis to identify risk factors for adverse psychological response. Results Elevated levels of perceived stress and depression, compared to population normative data, and moderate levels of death anxiety were noted. Levels of depression were similar to those found in comparable studies of family members of ICU patients admitted for other conditions. Multiple regression analysis indicated that increasing age and non-spousal family relationship were significantly associated with depression and perceived stress. Female gender, increasing age, and higher levels of education were significantly associated with high death anxiety. Comparisons with data collected in previous studies in the same hospital ICU with groups affected by a range of

  5. Epidemiological and clinical characteristics of patients who died from Influenza A(H1N1pdm09 in Viet Nam

    Phan Thanh Tinh


    Full Text Available We describe the epidemiological and clinical characteristics of patients who died from influenza A(H1N1pdm09 in hospitals in Viet Nam between August 2009 and March 2010.Of 58 fatal cases, 32 (55% were below 30 years of age and 14 (24% were pregnant females. Forty-five (78% patients had at least one underlying medical condition including chronic heart, kidney or lung diseases or pregnancy. Twelve (21% cases sought medical attention on the day of symptom onset. Only 13 (36% of 36 cases for whom treatment data were available had been given antiviral drugs within the recommended two days of symptom onset.The clinical and epidemiologic characteristics of the patients who died from influenza A(H1N1pdm09 are similar to those reported from other countries. To improve preparedness and response to future pandemics, Viet Nam needs to strengthen the surveillance of influenza; increase laboratory capacity to test for influenza viruses; and develop strategies for promoting the timely attendance of at-risk individuals at health facilities and the early administration of antiviral drugs, particularly for persons with underlying medical conditions and pregnant females.

  6. Surveillance of hospitalizations with pandemic A(H1N1 2009 influenza infection in Queensland, Australia

    Frances Birrell


    Full Text Available Objective : To describe the demographic and clinical characteristics of patients hospitalized with pandemic A(H1N1 2009 infection in Queensland, Australia between 25 May and 3 October 2009 and to examine the relationship between timing of antiviral treatment and severity of illness.Method: Using data from the Queensland Health EpiLog information system, descriptive analysis and logistic regression modelling were used to describe and model factors which influence patient outcomes (death, admission to intensive care unit and/or special care unit. Data on patients admitted to hospital in Queensland with confirmed pandemic A(H1N1 2009 infection were included in this analysis.Results: 1236 patients with pandemic A(H1N1 2009 infection were admitted to hospitals in Queensland during the study period. Of the total group: 15% were admitted to an intensive care unit or special care unit; 3% died; 34% were under the age of 18 years and 8% were 65 years of age or older; and 55% had at least one underlying medical condition. Among the 842 patients for whom data were available regarding the use of antiviral drugs, antiviral treatment was initiated in 737 (87.5% patients with treatment commencing at a median of one day (range 1–33 days after onset of illness. Admission to an intensive care unit or special care unit (ICU/SCU or death was significantly associated with increased age, lack of timeliness of antiviral treatment, chronic renal disease and morbid obesity.Discussion: Early antiviral treatment was significantly associated with lower likelihood of ICU/SCU admission or death. Early antiviral treatment for influenza cases may therefore have important public health implications.

  7. Performance of the Directigen EZ Flu A+B rapid influenza diagnostic test to detect pandemic influenza A/H1N1 2009.

    Boyanton, Bobby L; Almradi, Amro; Mehta, Tejal; Robinson-Dunn, Barbara


    The Directigen EZ Flu A+B rapid influenza diagnostic test, as compared to real-time reverse transcriptase polymerase chain reaction, demonstrated suboptimal performance to detect pandemic influenza A/H1N1 2009. Age- and viral load-stratified test sensitivity ranged from 33.3 to 84.6% and 0 to 100%, respectively. PMID:24582319

  8. 热毒宁注射液体外抑制甲型H1N1流感病毒的研究%In vitro inhibition of Reduning Injection on influenza A/H1N1 influenza virus

    孙兰; 段书敏; 周军; 王振中; 毕宇安; 萧伟


    目的:研究热毒宁注射液体外抑制甲型H1N1流感病毒的作用。方法以奥司他韦为阳性对照,采用CPE和MTT法观察热毒宁注射液对甲型H1N1流感病毒的抑制作用。结果 CPE法结果表明热毒宁注射液最大无毒浓度(TC0)为16.2 mg/mL,半数中毒浓度为(TC50)为(24.5±8.1)mg/mL;MTT法测定结果表明热毒宁注射液TC0为16.2 mg/mL,TC50为(21.7±9.4)mg/mL。热毒宁注射液体外抑制甲型H1N1流感病毒结果显示,CPE法和MTT法热毒宁注射液作用感染细胞1次组半数有效浓度(IC50)为(900.0±173.2)、(933.3±57.7)μg/mL,治疗指数(TI)为27.2、23.2;热毒宁注射液作用感染细胞3次组IC50为(666.7±115.5)、(866.7±208.1)μg/mL,TI为36.7、25.0。结论热毒宁注射液具有明显体外抗甲型H1N1流感病毒的作用。%Objective To study the inhibitory effects of Reduning Injection on influenza A/H1N1 influenza virusin vitro.Methods With Oseltamivir as positive control, CPE and MTT methods were used to observe inhibitory effects of Reduning Injection on influenza A/H1N1 influenza virusin vitro.Results The CPE method results showed that maximum of no toxicity concentration (TC0) of Reduning Injection was 16.2 mg/mL, and median toxic concentration (TC50) was (24.5 ± 8.1) mg/mL. The MTT method results showed that maximum of no toxicity concentration (TC0) was (16.2 ± 0) mg/mL, and median toxic concentration (TC50) was (21.7 ± 9.4) mg/mL. Thein vitro inhibition of influenza A/H1N1 influenza virus of Reduning Injection showed the administration of Reduning Injection to infected cells once, median toxic concentration (TC50) of the CPE method and the MTT method were (900.0 ± 173.2)μg/mL, (933.3 ± 57.7)μg/mL, therapeutic indexes (TI) were 27.2 and 23.2, and administration of Reduning Injection to infected cells for three times, median toxic concentration (TC50) of the CPE method and the MTT method were (666.7 ± 115.5)

  9. Excess mortality monitoring in England and Wales during the influenza A(H1N1) 2009 pandemic.

    Hardelid, P; Andrews, N; Pebody, R


    We present the results from a novel surveillance system for detecting excess all-cause mortality by age group in England and Wales developed during the pandemic influenza A(H1N1) 2009 period from April 2009 to March 2010. A Poisson regression model was fitted to age-specific mortality data from 1999 to 2008 and used to predict the expected number of weekly deaths in the absence of extreme health events. The system included adjustment for reporting delays. During the pandemic, excess all-cause mortality was seen in the 5-14 years age group, where mortality was flagged as being in excess for 1 week after the second peak in pandemic influenza activity; and in age groups >45 years during a period of very cold weather. This new system has utility for rapidly estimating excess mortality for other acute public health events such as extreme heat or cold weather. PMID:21439100

  10. Molecular findings from influenza A(H1N1pdm09 detected in patients from a Brazilian equatorial region during the pandemic period

    Maria José Couto Oliveira


    Full Text Available After the World Health Organization officially declared the end of the first pandemic of the XXI century in August 2010, the influenza A(H1N1pdm09 virus has been disseminated in the human population. In spite of its sustained circulation, very little on phylogenetic data or oseltamivir (OST resistance is available for the virus in equatorial regions of South America. In order to shed more light on this topic, we analysed the haemagglutinin (HA and neuraminidase (NA genes of influenza A(H1N1pdm09 positive samples collected during the pandemic period in the Pernambuco (PE, a northeastern Brazilian state. Complete HA sequences were compared and amino acid changes were related to clinical outcome. In addition, the H275Y substitution in NA, associated with OST resistance, was investigated by pyrosequencing. Samples from PE were grouped in phylogenetic clades 6 and 7, being clustered together with sequences from South and Southeast Brazil. The D222N/G HA gene mutation, associated with severity, was found in one deceased patient that was pregnant. Additionally, the HA mutation K308E, which appeared in Brazil in 2010 and was only detected worldwide the following year, was identified in samples from hospitalised cases. The resistance marker H275Y was not identified in samples tested. However, broader studies are needed to establish the real frequency of resistance in this Brazilian region.

  11. Risk factors and immunity in a nationally representative population following the 2009 influenza A(H1N1 pandemic.

    Don Bandaranayake

    Full Text Available BACKGROUND: Understanding immunity, incidence and risk factors of the 2009 influenza A(H1N1 pandemic (2009 H1N1 through a national seroprevalence study is necessary for informing public health interventions and disease modelling. METHODS AND FINDINGS: We collected 1687 serum samples and individual risk factor data between November-2009 to March-2010, three months after the end of the 2009 H1N1 wave in New Zealand. Participants were randomly sampled from selected general practices countrywide and hospitals in the Auckland region. Baseline immunity was measured from 521 sera collected during 2004 to April-2009. Haemagglutination inhibition (HI antibody titres of ≥1:40 against 2009 H1N1 were considered seroprotective as well as seropositive. The overall community seroprevalence was 26.7% (CI:22.6-29.4. The seroprevalence varied across age and ethnicity. Children aged 5-19 years had the highest seroprevalence (46.7%;CI:38.3-55.0, a significant increase from the baseline (14%;CI:7.2-20.8. Older adults aged ≥60 had no significant difference in seroprevalence between the serosurvey (24.8%;CI:18.7-30.9 and baseline (22.6%;CI:15.3-30.0. Pacific peoples had the highest seroprevalence (49.5%;CI:35.1-64.0. There was no significant difference in seroprevalence between both primary (29.6%;CI:22.6-36.5 and secondary healthcare workers (25.3%;CI:20.8-29.8 and community participants. No significant regional variation was observed. Multivariate analysis indicated age as the most important risk factor followed by ethnicity. Previous seasonal influenza vaccination was associated with higher HI titres. Approximately 45.2% of seropositive individuals reported no symptoms. CONCLUSIONS: Based on age and ethnicity standardisation to the New Zealand Population, about 29.5% of New Zealanders had antibody titers at a level consistent with immunity to 2009 H1N1. Around 18.3% of New Zealanders were infected with the virus during the first wave including about one child

  12. Mortality, severe acute respiratory infection, and influenza-like illness associated with influenza A(H1N1pdm09 in Argentina, 2009.

    Eduardo Azziz-Baumgartner

    Full Text Available INTRODUCTION: While there is much information about the burden of influenza A(H1N1pdm09 in North America, little data exist on its burden in South America. METHODS: During April to December 2009, we actively searched for persons with severe acute respiratory infection and influenza-like illness (ILI in three sentinel cities. A proportion of case-patients provided swabs for influenza testing. We estimated the number of case-patients that would have tested positive for influenza by multiplying the number of untested case-patients by the proportion who tested positive. We estimated rates by dividing the estimated number of case-patients by the census population after adjusting for the proportion of case-patients with missing illness onset information and ILI case-patients who visited physicians multiple times for one illness event. RESULTS: We estimated that the influenza A(H1N1pdm09 mortality rate per 100,000 person-years (py ranged from 1.5 among persons aged 5-44 years to 5.6 among persons aged ≥ 65 years. A(H1N1pdm09 hospitalization rates per 100,000 py ranged between 26.9 among children aged <5 years to 41.8 among persons aged ≥ 65 years. Influenza A(H1N1pdm09 ILI rates per 100 py ranged between 1.6 among children aged <5 to 17.1 among persons aged 45-64 years. While 9 (53% of 17 influenza A(H1N1pdm09 decedents with available data had obesity and 7 (17% of 40 had diabetes, less than 4% of surviving influenza A(H1N1pdm09 case-patients had these pre-existing conditions (p ≤ 0.001. CONCLUSION: Influenza A(H1N1pdm09 caused a similar burden of disease in Argentina as in other countries. Such disease burden suggests the potential value of timely influenza vaccinations.

  13. Acute respiratory distress syndrome (ARDS) complicating influenza A/H1N1v infection--a clinical approach.

    Witczak, Agnieszka; Prystupa, Andrzej; Kurys-Denis, Ewa; Borys, Michał; Czuczwar, Mirosław; Niemcewicz, Marcin; Kocik, Janusz; Michalak, Anna; Pietrzak, Aldona; Chodorowska, Grażyna; Krupski, Witold; Mosiewicz, Jerzy; Tomasiewicz, Krzysztof


    ARDS is defined as an acute inflammatory syndrome characterized with bilateral parenchymal lung infiltrates on chest radiograph and PaO2/FiO2 ratiofat embolism, surface burn, massive blood transfusion. Influenza A/H1N1 infection seems to be responsible for the development of extremely severe type of ARDS with poor response to routine treatment. Despite great progress in the management of ARDS with novel agents and sophisticated techniques, including antimicrobial drugs, extracorporeal membrane oxygenation, prostaglandins, nitric oxide, prostacyclin, exogenous surfactant administration and activated protein C, supportive treatment based mostly on advanced mechanical ventilation in the intensive care units seems to be the most important for the prognosis. PMID:24364461

  14. Surveillance of influenza viruses attacking children in Beijing during 2009 pandemic influenza A(H1N1)%2009甲型H1N1流感大流行期间北京儿童的流感监测

    朱汝南; 沙莉; 袁艺; 王菲; 胡凤华; 李杰; 胡岚; 张宝元; 曹玲; 金丽敏; 李娟娟; 钱渊; 王晓颖; 孙宇; 王芳; 邓洁; 赵林清; 曲东; 李颖; 任晓旭


    目的 了解2009年甲型H1N1流感大流行期间北京地区儿童中流感流行的情况.方法 采用WHO推荐的实时荧光定量RT-PCR和国家流感中心推荐的分型方法,对2009年甲型H1N1流感大流行期间因流感样症状来首都儿科研究所附属儿童医院就诊患儿的咽拭子标本进行流感病毒核酸检测.结果 2009年6月1日至2010年2月28日期间共检测了4363份咽拭子标本,其中623例为甲型H1N1阳性,阳性率为14.3%,657例为其他甲型流感病毒阳性(15.1%),所有甲型流感病毒的总阳性率为29.3%.623例中有23例为危重症病例(占阳性患者的3.7%),其中5例死亡.618例信息完整的甲型H1N1病例中,患儿年龄为14天~16岁,性别比例为男比女为1.3:1.1~3岁儿童占25.2%,3~6岁学龄前儿童和6~12岁学龄儿童所占比例相近,各约占30%.在监测期间,仅呈现了一个甲型H1N1的流行波.2009年11月达到最高峰,随后减弱,2010年2月快速下降至2.7%.对监测期间每周20~30份临床标本同时进行季节性流感的监测显示,季节性H3N2、甲型H1N1和乙型流感交替流行.呼吸道合胞病毒(RSV)在甲型H1N1流行趋势减缓后逐渐流行成为流行优势株.结论 2009年6月至2010年2月北京地区儿童中出现甲型H1N1的流行,主要累及学龄前和学龄儿童.季节性流感和RSV与甲型H1N1交替流行.%Objective To investigate the prevalence of influenza virus infections in infants and young children during the pandemic period of 2009 influenza A(H1N1)in Beijing.Methods Throat swabs were collected from children visited the affiliated Children's Hospital to Capital Institute of Pediatrics for influenza-like illness from June 1,2009 to February 28,2010.The specific gene segments of 2009 pandemic influenza H1N1 and seasonal influenza viruses were amplified from samples by real-time RT-PCR recommended by WHO and National Influenza Reference Center of China.Results Out of 4363 clinical samples tested by real

  15. Research on expulsion law of influenza A(H1N1) virus and antiviral therapy%甲型H1N1流感患者排毒规律及抗病毒治疗研究

    刘映霞; 杨桂林; 陈心春; 周伯平; 杨大国; 李慧涓; 高雪; 刘艳; 谢靖婧; 李建民; 刘水腾; 张明霞


    目的 研究2009年深圳市收治的甲型H1N1流感确诊病例排毒规律和抗病毒治疗疗效.方法 75例患者均经两次鼻咽拭子甲型H1N1流感病毒核酸检测阳性(RT-PCR),此后每天检测病毒核酸直至连续两天均阴性.第1次病毒检测阳性后立即随机分三组抗病毒治疗,分别为奥司他韦(Oseltamivir)(组Ⅰ)、中药(组Ⅱ)和奥司他韦联合中药(组Ⅲ)抗病毒治疗,5 d为一疗程.应用流式细胞仪检测T细胞亚群和IL-17表达.结果 75例患者中,78.7%(59/75)在起病后甲型H1N1流感病毒核酸阳性持续≤7 d,平均年龄为(22.25±10.38)岁;21.3%(16/75)病毒持续>7 d,年龄为(17.16±13.66)岁.对其中56例患者细胞与体液免疫功能进行分析,发现其IL-17表达明显低于季节性流感和健康人(P<0.01).进一步研究发现,10例病毒持续>7 d的患者IL-17表达值(1.91±0.80)明显低于46例病毒持续≤7 d者IL-17表达(3.05±1.59)(P<0.05),也明显低于季节性流感(P<0.01)和正常对照组(P<0.001).比较三治疗组抗病毒治疗5 d疗程结束时病毒核酸转阴率,分别为组Ⅲ92.86%,组Ⅰ71.43%,组Ⅱ46.15%,组Ⅱ明显低于前两组(分别为P<0.01,P<0.05).组Ⅲ经治疗后体温恢复正常时间较组Ⅰ、组Ⅱ缩短(P<0.05).结论 IL-17和年龄与甲型H1N1流感病毒感染及排毒时间长短可能存在一定关系.奥司他韦联合中药治疗在抗病毒疗效和减轻症状方面均有其独特优势.%Objective To investigate the A (H1N1 ) influenza patients whose viral expulsion law and antiviral effecacy in Shenzhen city in 2009. Methods A (H1N1) flu virus nucleic acid positive by reverse transcription-polymerasechain reaction (RT-PCR) with nose swabs pharynx swabs two times were showed in 75 patients. Thereafter, to detect the virus nucleic acid once per day until negative for two days in a row. Begin the antiviral therapy with Oseltamivir (Ⅰ) or the Chinese medicine (Ⅱ) or Oseltamivir combined the Chinese

  16. Origin and fate of A/H1N1 influenza in Scotland during 2009

    Lycett, S.; McLeish, N.J.; Robertson, C.; Carman, W; Baillie, G.; McMenamin, J.; Rambaut, A; Simmonds, P.; Woolhouse, M.; Leigh Brown, A.J.


    The spread of influenza has usually been described by a ‘density’ model, where the largest centres of population drive the epidemic within a country. An alternative model emphasizing the role of air travel has recently been developed. We have examined the relative importance of the two in the context of the 2009 H1N1 influenza epidemic in Scotland. We obtained genome sequences of 70 strains representative of the geographical and temporal distribution of H1N1 influenza during the summer and wi...

  17. Influenza A/H1N1 2009 pneumonia in kidney transplant recipients: characteristics and outcomes following high-dose oseltamivir exposure.

    Watcharananan, S P; Suwatanapongched, T; Wacharawanichkul, P; Chantratitaya, W; Mavichak, V; Mossad, S B


    We report 2 cases of severe pneumonia due to the novel pandemic influenza A/H1N1 2009 in kidney transplant recipients. Our patients initially experienced influenza-like illness that rapidly progressed to severe pneumonia within 48 h. The patients became hypoxic and required non-invasive ventilation. The novel influenza A/H1N1 2009 was identified from their nasal swabs. These cases were treated successfully with a relatively high dose of oseltamivir, adjusted for their renal function. Clinical improvement was documented only after a week of antiviral therapy. Despite early antiviral treatment, we showed that morbidity following novel pandemic influenza A/H1N1 2009 infection is high among kidney transplant recipients. PMID:20102550

  18. Effectiveness of pandemic and seasonal influenza vaccine in preventing pandemic influenza A(H1N1)2009 infection in England and Scotland 2009-2010.

    Hardelid, P; Fleming, D M; McMenamin, J; Andrews, N; Robertson, C; SebastianPillai, P; Ellis, J; Carman, W; Wreghitt, T; Watson, J M; Pebody, R G


    Following the global spread of pandemic influenza A(H1N1)2009, several pandemic vaccines have been rapidly developed. The United Kingdom and many other countries in the northern hemisphere implemented seasonal and pandemic influenza vaccine programmes in October 2009. We present the results of a case–control study to estimate effectiveness of such vaccines in preventing confirmed pandemic influenza infection. Some 5,982 individuals with influenza-like illness seen in general practices between November 2009 and January 2010 were enrolled. Those testing positive on PCR for pandemic influenza were assigned as cases and those testing negative as controls. Vaccine effectiveness was estimated as the relative reduction in odds of confirmed infection between vaccinated and unvaccinated individuals. Fourteen or more days after immunisation with the pandemic vaccine, adjusted vaccine effectiveness (VE) was 72% (95% confidence interval (CI): 21% to 90%). If protection was assumed to start after seven or more days, the adjusted VE was 71% (95% CI: 37% to 87%). Pandemic influenza vaccine was highly effective in preventing confirmed infection with pandemic influenza A(H1N1)2009 from one week after vaccination. No evidence of effectiveness against pandemic influenza A(H1N1)2009 was found for the 2009/10 trivalent seasonal influenza vaccine (adjusted VE of -30% (95% CI: -89% to 11%)). PMID:21251487

  19. Measuring the effect of influenza A(H1N1)pdm09: the epidemiological experience in the West Midlands, England during the 'containment' phase.

    Inglis, N J; Bagnall, H; Janmohamed, K; Suleman, S; Awofisayo, A; De Souza, V; Smit, E; Pebody, R; Mohamed, H; Ibbotson, S; Smith, G E; House, T; Olowokure, B


    The West Midlands was the first English region to report sustained community transmission during the 'containment' phase of the influenza A(H1N1)pdm09 pandemic in England. To describe the epidemiological experience in the region, West Midlands and national datasets containing laboratory-confirmed A(H1N1)pdm09 virus cases in the region during the 'containment' phase were analysed. The region accounts for about 10·5% of England's population, but reported about 42% of all laboratory-confirmed cases. Altogether 3063 cases were reported, with an incidence rate of 56/100 000 population. School-associated cases accounted for 25% of cases. Those aged <20 years, South Asian ethnic groups, and residents of urban and socioeconomically deprived areas were disproportionately affected. Imported cases accounted for 1% of known exposures. Regional R 0 central estimates between 1·41 and 1·43 were obtained. The West Midlands experience suggests that interpretation of transmission rates may be affected by complex interactions within and between sub-populations in the region. PMID:23731730

  20. Narcolepsy, 2009 A(H1N1) pandemic influenza, and pandemic influenza vaccinations: what is known and unknown about the neurological disorder, the role for autoimmunity, and vaccine adjuvants.

    Ahmed, S Sohail; Schur, Peter H; MacDonald, Noni E; Steinman, Lawrence


    The vaccine safety surveillance system effectively detected a very rare adverse event, narcolepsy, in subjects receiving AS03-adjuvanted A(H1N1) pandemic vaccine made using the European inactivation/purification protocol. The reports of increased cases of narcolepsy in non-vaccinated subjects infected with wild A(H1N1) pandemic influenza virus suggest a role for the viral antigen(s) in disease development. However, additional investigations are needed to better understand what factor(s) in wild influenza infection trigger(s) narcolepsy in susceptible hosts. An estimated 31 million doses of European AS03-adjuvanted A(H1N1) pandemic vaccine were used in more than 47 countries. The Canadian AS03-adjuvanted A(H1N1) pandemic vaccine was used with high coverage in Canada where an estimated 12 million doses were administered. As no similar narcolepsy association has been reported to date with the AS03-adjuvanted A(H1N1) pandemic vaccine made using the Canadian inactivation/purification protocol, this suggests that the AS03 adjuvant alone may not be responsible for the narcolepsy association. To date, no narcolepsy association has been reported with the MF59®-adjuvanted A(H1N1) pandemic vaccine. This review article provides a brief background on narcolepsy, outlines the different types of vaccine preparations including the ones for influenza, reviews the accumulated evidence for the safety of adjuvants, and explores the association between autoimmune diseases and natural infections. It concludes by assimilating the historical observations and recent clinical studies to formulate a feasible hypothesis on why vaccine-associated narcolepsy may not be solely linked to the AS03 adjuvant but more likely be linked to how the specific influenza antigen component of the European AS03-adjuvanted pandemic vaccine was prepared. Careful and long-term epidemiological studies of subjects who developed narcolepsy in association with AS03-adjuvanted A(H1N1) pandemic vaccine prepared with

  1. [How did the media report on the AH1N1 Influenza in Peru?].

    Palpan-Guerra, Ada; Munayco, César V


    We analyzed the characteristics of news issued by communication media (CM) in Peru on H1N1 influenza in 2013, for which written, radio, television and internet CM were reviewed daily. The news were classified according to framing, estimation (educational, informative and with high perception of risk of contagion and death) and scope. A descriptive analysis of the main variables of the study was made. The framing of the news was focused on influenza cases (47.5%) and actions of the Ministry of Health and other institutions (29.0%). The highest percentage of news was informative (73.7%), and only 7.5% were news with high perception of risk of contagion and death; the latter was more frequent in newspapers (9.0%) and television (9.4%). During 2013, the CM, in general, was responsible at the time of reporting, although there were some that spread news that could have increased the perception of risk in the population. PMID:26338390

  2. Bayesian modeling to unmask and predict influenza A/H1N1pdm dynamics in London.

    Birrell, Paul J; Ketsetzis, Georgios; Gay, Nigel J; Cooper, Ben S; Presanis, Anne M; Harris, Ross J; Charlett, André; Zhang, Xu-Sheng; White, Peter J; Pebody, Richard G; De Angelis, Daniela


    The tracking and projection of emerging epidemics is hindered by the disconnect between apparent epidemic dynamics, discernible from noisy and incomplete surveillance data, and the underlying, imperfectly observed, system. Behavior changes compound this, altering both true dynamics and reporting patterns, particularly for diseases with nonspecific symptoms, such as influenza. We disentangle these effects to unravel the hidden dynamics of the 2009 influenza A/H1N1pdm pandemic in London, where surveillance suggests an unusual dominant peak in the summer. We embed an age-structured model into a bayesian synthesis of multiple evidence sources to reveal substantial changes in contact patterns and health-seeking behavior throughout the epidemic, uncovering two similar infection waves, despite large differences in the reported levels of disease. We show how this approach, which allows for real-time learning about model parameters as the epidemic progresses, is also able to provide a sequence of nested projections that are capable of accurately reflecting the epidemic evolution. PMID:22042838

  3. Immunogenicity and Efficacy of A/H1N1pdm Vaccine Among Subjects With Severe Motor and Intellectual Disability in the 2010/11 Influenza Season

    Hara, Megumi; Hanaoka, Tomoyuki; Maeda, Kazuhiro; Kase, Tetsuo; Ohfuji, Satoko; Fukushima, Wakaba; Hirota, Yoshio


    Background While the immunogenicity and effectiveness of seasonal influenza vaccines among subjects with severe motor and intellectual disability (SMID) are known to be diminished, the efficacy of the A/H1N1pdm vaccine has not been evaluated. Methods We prospectively evaluated 103 subjects with SMID (mean age, 41.7 years) who received trivalent inactivated influenza vaccine during the 2010/11 influenza season. The hemagglutination inhibition (HI) antibody titer was measured in serum samples collected pre-vaccination (S0), post-vaccination (S1), and end-of-season (S2) to evaluate subjects’ immunogenicity capacity. Vaccine efficacy was assessed based on antibody efficacy and achievement proportion. Results The proportions of seroprotection and seroconversion, and the geometric mean titer (GMT) ratio (GMT at S1/GMT at S0) for A/H1N1pdm were 46.0%, 16.0%, and 1.8, respectively—values which did not meet the European Medicines Evaluation Agency criteria. The achievement proportion was 26%. During follow-up, 11 of 43 subjects with acute respiratory illness were diagnosed with type A influenza according to a rapid influenza diagnostic test (RIDT), and A/H1N1pdm strains were isolated from the throat swabs of 5 of those 11 subjects. When either or both RIDT-diagnosed influenza or serologically diagnosed influenza (HI titer at S2/HI titer at S1 ≥2) were defined as probable influenza, subjects with A/H1N1pdm seroprotection were found to have a lower incidence of probable influenza (odds ratio, 0.31; antibody efficacy, 69%; vaccine efficacy, 18%). Conclusions In the present seasonal assessment, antibody efficacy was moderate against A/H1N1pdm among SMID subjects, but vaccine efficacy was low due to the reduced immunogenicity of SMID subjects. PMID:26780860

  4. The European I-MOVE Multicentre 2013-2014 Case-Control Study. Homogeneous moderate influenza vaccine effectiveness against A(H1N1)pdm09 and heterogenous results by country against A(H3N2).

    Valenciano, Marta


    In the first five I-MOVE (Influenza Monitoring Vaccine Effectiveness in Europe) influenza seasons vaccine effectiveness (VE) results were relatively homogenous among participating study sites. In 2013-2014, we undertook a multicentre case-control study based on sentinel practitioner surveillance networks in six European Union (EU) countries to measure 2013-2014 influenza VE against medically-attended influenza-like illness (ILI) laboratory-confirmed as influenza. Influenza A(H3N2) and A(H1N1)pdm09 viruses co-circulated during the season.

  5. Coverage and side effects of influenza A(H1N1) 2009 monovalent vaccine among primary health care workers.

    Ortiz Arjona, Miguel Angel; Abd Elaziz, Khaled Mahmoud; Caballero Lanzas, Jose Maria; Allam, Mohamed Farouk


    In June 2009, WHO declared the maximum phase alert against H1N1 pandemic flu. Health care workers (HCWs) are considered a strategic target for prevention of the occurrence of H1N1 influenza since they had the greatest risk of acquiring infection. The objectives of our study were (1) identifying the uptake of influenza A(H1N1) 2009 monovalent vaccine by primary health care workers in the southern part of Cordoba, and (2) reporting of the adverse events occurred after vaccination. We followed 240 HCWs in 12 primary health care centres at southern part of Cordoba for vaccine uptake and the occurrence of adverse events. The coverage rate with H1N1 vaccine was 20.5% which was lower compared to seasonal influenza vaccination rate 44.2% in 2009. Males had higher H1N1 vaccination rate compared to females with no significant difference. Senior HCWs complied more with seasonal influenza vaccine while this finding was not consistent with H1N1 vaccination. Multivariate analysis showed that the only independent variable that affected H1N1 vaccine was the compliance to the seasonal flu vaccine in the past three years with OR 5.1 and 95% CI (2.4-10.8). Adverse events occurred among 26.5% of those who complied with H1N1 vaccination. Those were local pain, irritation and induration at site of injection (38.5%), fever (15.4%), fever cough and rhinorrhea (15.4%) generalized pain and lumber pains (23.1%). The low vaccination rate in this study is consistent with previous studies done in many parts of the world and in Spain. Further studies should be done to explore the factors that hindered the uptake and resistance of HCWs to vaccination to H1N1 vaccine. PMID:21840463

  6. Risk Factors for Mortality among 2009 A/H1N1 Influenza Hospitalizations in Maricopa County, Arizona, April 2009 to March 2010

    Chowell, G.; Ayala, A; Berisha, V.; Viboud, C.; Schumacher, M.


    We analyzed individual-level data on pandemic influenza A/H1N1pdm hospitalizations from the enhanced surveillance system of the Maricopa County Department of Public Health, AZ, USA from April 1st, 2009 to March 31st, 2010. We also assessed the the risk of death among A/H1N1 hospitalizations using multivariate logistic regression. Hospitalization rates were significantly higher among Native Americans (risk ratio (RR)   =   6.2; 95% CI: 6.15, 6.21), non-Hispanic Black (RR = 3.84; 95% CI: 3.8, 3...

  7. Risk Factors for Mortality among 2009 A/H1N1 Influenza Hospitalizations in Maricopa County, Arizona, April 2009 to March 2010

    Chowell, G.; Ayala, A; Berisha, V.; Viboud, C.; Schumacher, M.


    We analyzed individual-level data on pandemic influenza A/H1N1pdm hospitalizations from the enhanced surveillance system of the Maricopa County Department of Public Health, AZ, USA from April 1st, 2009 to March 31st, 2010. We also assessed the the risk of death among A/H1N1 hospitalizations using multivariate logistic regression. Hospitalization rates were significantly higher among Native Americans (risk ratio (RR)  =  6.2; 95% CI: 6.15, 6.21), non-Hispanic Black (RR = 3.84; 95% CI: 3.8, 3.9...

  8. Mortality, Severe Acute Respiratory Infection, and Influenza-Like Illness Associated with Influenza A(H1N1)pdm09 in Argentina, 2009

    Azziz-Baumgartner, Eduardo; Cabrera, Ana María; Chang, Loretta; Calli, Rogelio; Kusznierz, Gabriela; Baez, Clarisa; Yedlin, Pablo; Zamora, Ana María; Cuezzo, Romina; Sarrouf, Elena Beatriz; Uboldi, Andrea; Herrmann, Juan; Zerbini, Elsa; Uez, Osvaldo; Rico Cordeiro, Pedro Osvaldo


    Introduction While there is much information about the burden of influenza A(H1N1)pdm09 in North America, little data exist on its burden in South America. Methods During April to December 2009, we actively searched for persons with severe acute respiratory infection and influenza-like illness (ILI) in three sentinel cities. A proportion of case-patients provided swabs for influenza testing. We estimated the number of case-patients that would have tested positive for influenza by multiplying ...


    Miguel Martín Martínez


    Full Text Available An attempt is made to estimate the main parameters of the 2009 Influenza type A(H1N1 outburst in USA based on public information provided by Centers for Disease Control (CDC during the early stage of the epidemic. Given the ill-posed nature of the statistical problem, a nonlinear fuction estimation method (Gauss-Newton and Hooke Jeeves was combined with linearization procedures that allowed to set adequate initial guess values for estimation. Based on data until May 13th, 2009, the following values are predicted for the USA outbreak: Tau (time to the peak of incidence 32 days; R0 (number of secondary infections per infected individual 1.7; K (total number of cases 20000(15000-35000. These results are in good agreement with the values reported by the WHO's Rapid Assessment Team for the outburst in Mexico. The method can be applied in any setting where cumulative number of cases are properly recorded.

  10. 2009年新型甲型H1N1流感病毒聚合酶编码基因的遗传特性及重要功能位点变异分析%Genetic characteristics and variations at important functional sites of polymerase coding genes of the novel A/H1N1 influenza pandemic virus in 2009

    韩磊; 谢佳新; 殷建华; 韩一芳; 鹿文英; 曹广文


    Objective To elucidate the hereditary characteristics and variations of important functional domains of polymerase PA, PB1 and PB2 gene of the novel A/H1N1 influenza pandemic virus in 2009. Methods The sequences of PA, PB1 and PB2 gene of the novel A/H1N1 strains, and the reference sequences according to the years, locations, hosts and subtypes of influenza virus were retrieved from NCBI database. All the sequences were contrasted with MEGA4.0 software. The phylogenetic tree was constructed with the neighbor-joining method. All the deduced PB2 protein sequences were compared among the influenza strains, the avian influenza virus and the human A/H1N1 influenza virus found in different years. Results The sequence homology exceeded 99. 8% of PA, PB1 and PB2 gene of the novel A/H1N1 influenza virus isolated from different locations and different time. The sequences of PA, PB1 and PB2 gene isolated from different locations and time showed a high homology, clustered in a unique new clade, and close to avain influenza virus. Phylogenesis indicated that all the PA, PB1 and PB2 gene originally evolved from avain influenza virus. Alignments of the deduced protein sequences showed that the 627th amino acid of the PB2 gene of novel A/H1N1 strains was glutamic acid (Glu) , which was the same as that of avian influenza virus, rather than human H1N1 virus. Conclusions The novel A/H1N1 influenza virus from the same origin leads to the outbreak in 2009, and it is of atypical high pathogenicity. The polymerase gene of avian influenza virus might partially reassort with the novel A/H1N1 virus.%目的 分析2009年新型甲型H1N1流感病毒聚合酶PA、PB1和PB2编码基因序列遗传的进化特征及重要功能位点变异.方法 从NCBI流感数据库中获取此次流行株的PA、PB1和PB2聚合酶编码基因序列以及不同年代、不同地区、不同宿主、不同亚型的参考序列,运用MEGA4.0软件比对和修剪此次流行株的代表

  11. Using high-throughput sequencing to leverage surveillance of genetic diversity and oseltamivir resistance: a pilot study during the 2009 influenza A(H1N1 pandemic.

    Juan Téllez-Sosa

    Full Text Available BACKGROUND: Influenza viruses display a high mutation rate and complex evolutionary patterns. Next-generation sequencing (NGS has been widely used for qualitative and semi-quantitative assessment of genetic diversity in complex biological samples. The "deep sequencing" approach, enabled by the enormous throughput of current NGS platforms, allows the identification of rare genetic viral variants in targeted genetic regions, but is usually limited to a small number of samples. METHODOLOGY AND PRINCIPAL FINDINGS: We designed a proof-of-principle study to test whether redistributing sequencing throughput from a high depth-small sample number towards a low depth-large sample number approach is feasible and contributes to influenza epidemiological surveillance. Using 454-Roche sequencing, we sequenced at a rather low depth, a 307 bp amplicon of the neuraminidase gene of the Influenza A(H1N1 pandemic (A(H1N1pdm virus from cDNA amplicons pooled in 48 barcoded libraries obtained from nasal swab samples of infected patients (n  =  299 taken from May to November, 2009 pandemic period in Mexico. This approach revealed that during the transition from the first (May-July to second wave (September-November of the pandemic, the initial genetic variants were replaced by the N248D mutation in the NA gene, and enabled the establishment of temporal and geographic associations with genetic diversity and the identification of mutations associated with oseltamivir resistance. CONCLUSIONS: NGS sequencing of a short amplicon from the NA gene at low sequencing depth allowed genetic screening of a large number of samples, providing insights to viral genetic diversity dynamics and the identification of genetic variants associated with oseltamivir resistance. Further research is needed to explain the observed replacement of the genetic variants seen during the second wave. As sequencing throughput rises and library multiplexing and automation improves, we foresee that

  12. Analysis of the effectiveness of interventions used during the 2009 A/H1N1 influenza pandemic

    Milne George J


    Full Text Available Abstract Background Following the emergence of the A/H1N1 2009 influenza pandemic, public health interventions were activated to lessen its potential impact. Computer modelling and simulation can be used to determine the potential effectiveness of the social distancing and antiviral drug therapy interventions that were used at the early stages of the pandemic, providing guidance to public health policy makers as to intervention strategies in future pandemics involving a highly pathogenic influenza strain. Methods An individual-based model of a real community with a population of approximately 30,000 was used to determine the impact of alternative interventions strategies, including those used in the initial stages of the 2009 pandemic. Different interventions, namely school closure and antiviral strategies, were simulated in isolation and in combination to form different plausible scenarios. We simulated epidemics with reproduction numbers R0of 1.5, which aligns with estimates in the range 1.4-1.6 determined from the initial outbreak in Mexico. Results School closure of 1 week was determined to have minimal effect on reducing overall illness attack rate. Antiviral drug treatment of 50% of symptomatic cases reduced the attack rate by 6.5%, from an unmitigated rate of 32.5% to 26%. Treatment of diagnosed individuals combined with additional household prophylaxis reduced the final attack rate to 19%. Further extension of prophylaxis to close contacts (in schools and workplaces further reduced the overall attack rate to 13% and reduced the peak daily illness rate from 120 to 22 per 10,000 individuals. We determined the size of antiviral stockpile required; the ratio of the required number of antiviral courses to population was 13% for the treatment-only strategy, 25% for treatment and household prophylaxis and 40% for treatment, household and extended prophylaxis. Additional simulations suggest that coupling school closure with the antiviral

  13. Changes in heterosubtypic antibody responses during the first year of the 2009 A(H1N1) influenza pandemic

    Freidl, Gudrun S; Henk-Jan van den Ham; Boni, Maciej F.; Erwin de Bruin; Koopmans, Marion P.G.


    textabstractSeropositivity to avian influenza (AI) via low-level antibody titers has been reported in the general population and poultry-exposed individuals, raising the question whether these findings reflect true infection with AI or cross-reactivity. Here we investigated serological profiles against human and avian influenza viruses in the general population using a protein microarray platform. We hypothesized that higher antibody diversity across recent H1 and H3 influenza viruses would b...

  14. Dependence of the results of ecological-epidemic investigation of influenza A(H1N1) on immunity

    Fathudinova, Mohinav; Alimova, Barno; Rahimova, Halima


    This report presents the results of ecology-epidemical and immunological researches influ-enza virus A (H1 N1) and acute respiratory infection in Dushanbe from 2011 till 2015. The received results epidemiological and immunological analysis showed us, that last years has been changed not only characteristics of influenza epidemic, but it can not be notice the low-er of intensively of the collective immunity to actual versions influenza viruses A and B

  15. Functional balance between the hemagglutinin and neuraminidase of influenza A(H1N1pdm09 HA D222 variants.

    Jean-Sébastien Casalegno

    Full Text Available D222G/N substitutions in A(H1N1pdm09 hemagglutinin may be associated with increased binding of viruses causing low respiratory tract infections and human pathogenesis. We assessed the impact of such substitutions on the balance between hemagglutinin binding and neuraminidase cleavage, viral growth and in vivo virulence.Seven viruses with differing polymorphisms at codon 222 (2 with D, 3 G, 1 N and 1 E were isolated from patients and characterized with regards hemagglutinin binding affinity (Kd to α-2,6 sialic acid (SAα-2,6 and SAα-2,3 and neuraminidase enzymatic properties (Km, Ki and Vmax. The hemagglutination assay was used to quantitatively assess the balance between hemagglutinin binding and neuraminidase cleavage. Viral growth properties were compared in vitro in MDCK-SIAT1 cells and in vivo in BALB/c mice. Compared with D222 variants, the binding affinity of G222 variants was greater for SAα-2,3 and lower for SAα-2,6, whereas that of both E222 and N222 variants was greater for both SAα-2,3 and SAα-2,6. Mean neuraminidase activity of D222 variants (16.0 nmol/h/10(6 was higher than that of G222 (1.7 nmol/h/10(6 viruses and E/N222 variants (4.4 nmol/h/10(6 viruses. The hemagglutination assay demonstrated a deviation from functional balance by E222 and N222 variants that displayed strong hemagglutinin binding but weak neuraminidase activity. This deviation impaired viral growth in MDCK-SIAT1 cells but not infectivity in mice. All strains but one exhibited low infectious dose in mice (MID50 and replicated to high titers in the lung; this D222 strain exhibited a ten-fold higher MID50 and replicated to low titers. Hemagglutinin-neuraminidase balance status had a greater impact on viral replication than hemagglutinin affinity strength, at least in vitro, thus emphasizing the importance of an optimal balance for influenza virus fitness. The mouse model is effective in assessing binding to SAα-2,3 but cannot differentiate SAα-2,3- from SA

  16. A/H1N1 pandemic influenza vaccination: A retrospective evaluation of adverse maternal, fetal and neonatal outcomes in a cohort of pregnant women in Italy.

    Fabiani, Massimo; Bella, Antonino; Rota, Maria C; Clagnan, Elena; Gallo, Tolinda; D'Amato, Maurizio; Pezzotti, Patrizio; Ferrara, Lorenza; Demicheli, Vittorio; Martinelli, Domenico; Prato, Rosa; Rizzo, Caterina


    Although concerns about safety of influenza vaccination during pregnancy have been raised in the past, vaccination of pregnant women was recommended in many countries during the 2009 A/H1N1 pandemic influenza. A retrospective cohort study was conducted to evaluate the risk of adverse maternal, fetal and neonatal outcomes among pregnant women vaccinated with a MF59-adjuvanted A/H1N1 pandemic influenza vaccine. The study was carried out in four Italian regions (Piemonte, Friuli-Venezia-Giulia, Lazio, and Puglia) among 102,077 pregnant women potentially exposed during the second or third trimester of gestation to the vaccination campaign implemented in 2009/2010. Based on data retrieved from the regional administrative databases, the statistical analysis was performed using the Cox proportional-hazards model, adjusting for the propensity score to account for the potential confounding effect due to the socio-demographic characteristics and the clinical and reproductive history of women. A total of 100,332 pregnant women were eligible for the analysis. Of these, 2003 (2.0%) received the A/H1N1 pandemic influenza vaccination during the second or third trimester of gestation. We did not observe any statistically significant association between the A/H1N1 pandemic influenza vaccination and different maternal outcomes (hospital admissions for influenza, pneumonia, hypertension, eclampsia, diabetes, thyroid disease, and anaemia), fetal outcomes (fetal death after the 22nd gestational week) and neonatal outcomes (pre-term birth, low birth weight, low 5-min Apgar score, and congenital malformations). Pre-existing health-risk conditions (hospital admissions and drug prescriptions for specific diseases before the onset of pregnancy) were observed more frequently among vaccinated women, thus suggesting that concomitant chronic conditions increased vaccination uptake. The results of this study add some evidence on the safety of A/H1N1 pandemic influenza vaccination during

  17. A Novel Duplex Real-Time Reverse-Transcription PCR Assay for the Detection of Influenza A and the Novel Influenza A(H1N1 Strain

    Theo P. Sloots


    Full Text Available Timely implementation of antiviral treatment and other public health based responses are dependent on accurate and rapid diagnosis of the novel pandemic influenza A(H1N1 strain. In this study we developed a duplex real-time PCR (RT-PCR (dFLU-TM assay for the simultaneous detection of a broad range of influenza A subtypes and specific detection of the novel H1N1 2009 pandemic strain. The assay was compared to the combined results of two previously described monoplex RT-PCR assays using 183 clinical samples and 10 seasonal influenza A isolates. Overall, the results showed that the dFLU-TM RT-PCR method is suitable for detection of influenza A, including the novel H1N1 pandemic strain, in clinical samples.

  18. The impact of immunosenescence on humoral immune response variation after influenza A/H1N1 vaccination in older subjects.

    Iana H Haralambieva

    Full Text Available Although influenza causes significant morbidity and mortality in the elderly, the factors underlying the reduced vaccine immunogenicity and efficacy in this age group are not completely understood. Age and immunosenescence factors, and their impact on humoral immunity after influenza vaccination, are of growing interest for the development of better vaccines for the elderly.We assessed associations between age and immunosenescence markers (T cell receptor rearrangement excision circles - TREC content, peripheral white blood cell telomerase - TERT expression and CD28 expression on T cells and influenza A/H1N1 vaccine-induced measures of humoral immunity in 106 older subjects at baseline and three timepoints post-vaccination.TERT activity (TERT mRNA expression was significantly positively correlated with the observed increase in the influenza-specific memory B cell ELISPOT response at Day 28 compared to baseline (p-value=0.025. TREC levels were positively correlated with the baseline and early (Day 3 influenza A/H1N1-specific memory B cell ELISPOT response (p-value=0.042 and p-value=0.035, respectively. The expression and/or expression change of CD28 on CD4+ and/or CD8+ T cells at baseline and Day 3 was positively correlated with the influenza A/H1N1-specific memory B cell ELISPOT response at baseline, Day 28 and Day 75 post-vaccination. In a multivariable analysis, the peak antibody response (HAI and/or VNA at Day 28 was negatively associated with age, the percentage of CD8+CD28 low T cells, IgD+CD27- naïve B cells, and percentage overall CD20- B cells and plasmablasts, measured at Day 3 post-vaccination. The early change in influenza-specific memory B cell ELISPOT response was positively correlated with the observed increase in influenza A/H1N1-specific HAI antibodies at Day 28 and Day 75 relative to baseline (p-value=0.007 and p-value=0.005, respectively.Our data suggest that influenza-specific humoral immunity is significantly influenced by

  19. Risk Factors for Mortality among 2009 A/H1N1 Influenza Hospitalizations in Maricopa County, Arizona, April 2009 to March 2010

    G. Chowell


    Full Text Available We analyzed individual-level data on pandemic influenza A/H1N1pdm hospitalizations from the enhanced surveillance system of the Maricopa County Department of Public Health, AZ, USA from April 1st, 2009 to March 31st, 2010. We also assessed the the risk of death among A/H1N1 hospitalizations using multivariate logistic regression. Hospitalization rates were significantly higher among Native Americans (risk ratio (RR  =  6.2; 95% CI: 6.15, 6.21, non-Hispanic Black (RR = 3.84; 95% CI: 3.8, 3.9, and Hispanics (RR = 2.0; 95% CI: 2.0, 2.01 compared to non-Hispanic Whites. Throughout the spring, 59.2% of hospitalized patients received antiviral treatment; the proportion of patients treated increased significantly during the fall to 74.4% (Chi-square test, P<0.0001. In our best-fit logistic model, the adjusted risk of death among A/H1N1 inpatients was significantly higher during the fall wave (August 16, 2009 to March 31, 2010, OR = 3.94; 95% CI: 1.72, 9.03 compared to the spring wave (April 1, 2009 to August 15, 2009. Moreover, chronic lung disease (OR = 3.5; 95% CI: 1.7, 7.4, cancer within the last 12 months (OR = 4.3; 95%CI: 1.3, 14.8, immuno-suppression (OR = 4.0; 95% CI: 1.84, 8.9, and admission delays (OR = 4.6; 95% CI: 2.2, 9.5 were significantly associated with an increased the risk of death among A/H1N1 inpatients.

  20. Risk factors for mortality among 2009 A/H1N1 influenza hospitalizations in Maricopa County, Arizona, April 2009 to March 2010.

    Chowell, G; Ayala, A; Berisha, V; Viboud, C; Schumacher, M


    We analyzed individual-level data on pandemic influenza A/H1N1pdm hospitalizations from the enhanced surveillance system of the Maricopa County Department of Public Health, AZ, USA from April 1st, 2009 to March 31st, 2010. We also assessed the the risk of death among A/H1N1 hospitalizations using multivariate logistic regression. Hospitalization rates were significantly higher among Native Americans (risk ratio (RR)  =  6.2; 95% CI: 6.15, 6.21), non-Hispanic Black (RR = 3.84; 95% CI: 3.8, 3.9), and Hispanics (RR = 2.0; 95% CI: 2.0, 2.01) compared to non-Hispanic Whites. Throughout the spring, 59.2% of hospitalized patients received antiviral treatment; the proportion of patients treated increased significantly during the fall to 74.4% (Chi-square test, P < 0.0001). In our best-fit logistic model, the adjusted risk of death among A/H1N1 inpatients was significantly higher during the fall wave (August 16, 2009 to March 31, 2010, OR = 3.94; 95% CI: 1.72, 9.03) compared to the spring wave (April 1, 2009 to August 15, 2009). Moreover, chronic lung disease (OR = 3.5; 95% CI: 1.7, 7.4), cancer within the last 12 months (OR = 4.3; 95%CI: 1.3, 14.8), immuno-suppression (OR = 4.0; 95% CI: 1.84, 8.9), and admission delays (OR = 4.6; 95% CI: 2.2, 9.5) were significantly associated with an increased the risk of death among A/H1N1 inpatients. PMID:22844347

  1. Risk Factors for Mortality among 2009 A/H1N1 Influenza Hospitalizations in Maricopa County, Arizona, April 2009 to March 2010

    Chowell, G.; Ayala, A.; Berisha, V.; Viboud, C.; Schumacher, M.


    We analyzed individual-level data on pandemic influenza A/H1N1pdm hospitalizations from the enhanced surveillance system of the Maricopa County Department of Public Health, AZ, USA from April 1st, 2009 to March 31st, 2010. We also assessed the the risk of death among A/H1N1 hospitalizations using multivariate logistic regression. Hospitalization rates were significantly higher among Native Americans (risk ratio (RR)  =  6.2; 95% CI: 6.15, 6.21), non-Hispanic Black (RR = 3.84; 95% CI: 3.8, 3.9), and Hispanics (RR = 2.0; 95% CI: 2.0, 2.01) compared to non-Hispanic Whites. Throughout the spring, 59.2% of hospitalized patients received antiviral treatment; the proportion of patients treated increased significantly during the fall to 74.4% (Chi-square test, P < 0.0001). In our best-fit logistic model, the adjusted risk of death among A/H1N1 inpatients was significantly higher during the fall wave (August 16, 2009 to March 31, 2010, OR = 3.94; 95% CI: 1.72, 9.03) compared to the spring wave (April 1, 2009 to August 15, 2009). Moreover, chronic lung disease (OR = 3.5; 95% CI: 1.7, 7.4), cancer within the last 12 months (OR = 4.3; 95%CI: 1.3, 14.8), immuno-suppression (OR = 4.0; 95% CI: 1.84, 8.9), and admission delays (OR = 4.6; 95% CI: 2.2, 9.5) were significantly associated with an increased the risk of death among A/H1N1 inpatients. PMID:22844347

  2. 许昌地区新型甲型H1N1流感合并细菌感染分析%Analyze on Novel A/H1N1 influenza infected by bacteria in Xuchang area

    任丽娟; 艾根伟


    目的 研究新型甲型H1N1流感患者合并细菌感染情况.方法 收集咽拭子标本800份,检测其甲型H1N1流感病毒RNA,同时做咽拭子的细菌培养,根据结果 分析甲型H1N1流感患者合并细菌感染及致病菌的药敏情况.结果 800份样本中423例H1N1 RNA阳性;其中73例合并不同的细菌感染,占甲流患者的17%,多数细菌的耐药性较强.结论 许昌地区2009年的甲流疫情中,甲流患者合并细菌感染的情况值得关注,治疗中要注意细菌培养并合理用药.%Objective To research the patients with Novel A/H1N1 who had infected by bacteria.Methods To collect 800 examples of fauces swabs and incubat the swabs and detect the novel A( H1N1 ) influenza virus RNA,on the basis of the results,we could analyze whether the novel A/H1N1 influenza patients infected by bacteria.Results There were 423 patients who had infected by novel A/H1N1 influenza and 73( 17% ) of them had co-infected by bacteria,most of the bacteria were drug fast.Conclusions During the epidemic disease of novel A/H1N1 influenza in Xuchang area in 2009, the co-infected by bacteria and A/H1N1 should be payed more attention, furthermore, we should gave our attention to germicultue and prescribe medicines in reason.

  3. Early assessment of anxiety and behavioral response to novel swine-origin influenza A(H1N1)

    James Holland Jones; Marcel Salathé


    BACKGROUND: Since late April, 2009, a novel influenza virus A (H1N1), generally referred to as the "swine flu," has spread around the globe and infected hundreds of thousands of people. During the first few days after the initial outbreak in Mexico, extensive media coverage together with a high degree of uncertainty about the transmissibility and mortality rate associated with the virus caused widespread concern in the population. The spread of an infectious disease can be strongly influenced...

  4. Potentially-toxic and essential elements profile of AH1N1 patients in Mexico City

    Mireya Moya; Edgar G. Bautista; Antonio Velázquez-González; Felipe Vázquez-Gutiérrez; Guadalupe Tzintzun; María Elena García-Arreola; Manuel Castillejos; Andrés Hernández


    During spring of 2009, a new influenza virus AH1N1 spread in the world causing acute respiratory illness and death, resulting in the first influenza pandemic since 1968. Blood levels of potentially-toxic and essential elements of 40 pneumonia and confirmed AH1N1 were evaluated against two different groups of controls, both not infected with the pandemic strain. Significant concentrations of potentially-toxic elements (lead, mercury, cadmium, chromium, arsenic) along with deficiency of seleniu...

  5. Morbid obesity as a risk factor for hospitalization and death due to 2009 pandemic influenza A(H1N1 disease.

    Oliver W Morgan

    Full Text Available BACKGROUND: Severe illness due to 2009 pandemic A(H1N1 infection has been reported among persons who are obese or morbidly obese. We assessed whether obesity is a risk factor for hospitalization and death due to 2009 pandemic influenza A(H1N1, independent of chronic medical conditions considered by the Advisory Committee on Immunization Practices (ACIP to increase the risk of influenza-related complications. METHODOLOGY/PRINCIPAL FINDINGS: We used a case-cohort design to compare cases of hospitalizations and deaths from 2009 pandemic A(H1N1 influenza occurring between April-July, 2009, with a cohort of the U.S. population estimated from the 2003-2006 National Health and Nutrition Examination Survey (NHANES; pregnant women and children or=20 year olds, hospitalization was associated with being morbidly obese (BMI>or=40 for individuals with ACIP-recognized chronic conditions (OR = 4.9, 95% CI 2.4-9.9 and without ACIP-recognized chronic conditions (OR = 4.7, 95%CI 1.3-17.2. Among 2-19 year olds, hospitalization was associated with being underweight (BMIor=20 years without ACIP-recognized chronic medical conditions death was associated with obesity (OR = 3.1, 95%CI: 1.5-6.6 and morbid obesity (OR = 7.6, 95%CI 2.1-27.9. CONCLUSIONS/SIGNIFICANCE: Our findings support observations that morbid obesity may be associated with hospitalization and possibly death due to 2009 pandemic H1N1 infection. These complications could be prevented by early antiviral therapy and vaccination.

  6. Effectiveness of seasonal 2010/11 and pandemic influenza A(H1N1)2009 vaccines in preventing influenza infection in the United Kingdom: mid-season analysis 2010/11.

    Pebody, R; Hardelid, P; Fleming, Dm; McMenamin, J; Andrews, N; Robertson, C; Thomas, Dr; Sebastianpillai, P; Ellis, J; Carman, W; Wreghitt, T; Zambon, M; Watson, Jm


    This study provides mid-season estimates of the effectiveness of 2010/11 trivalent influenza vaccine and previous vaccination with monovalent influenza A(H1N1)2009 vaccine in preventing confirmed influenza A(H1N1)2009 infection in the United Kingdom in the 2010/11 season. The adjusted vaccine effectiveness was 34% (95% CI: -10 - 60%) if vaccinated only with monovalent vaccine in the 2009/10 season; 46% (95% CI: 7 - 69%) if vaccinated only with trivalent influenza vaccine in the 2010/11 season and 63% (95% CI: 37 - 78%) if vaccinated in both seasons. PMID:21329644

  7. Age-specific vaccine effectiveness of seasonal 2010/2011 and pandemic influenza A(H1N1) 2009 vaccines in preventing influenza in the United Kingdom.

    Pebody, R G; Andrews, N; Fleming, D M; McMenamin, J; Cottrell, S; Smyth, B; Durnall, H; Robertson, C; Carman, W; Ellis, J; Sebastian-Pillai, P; Zambon, M; Kearns, C; Moore, C; Thomas, D Rh; Watson, J M


    An analysis was undertaken to measure age-specific vaccine effectiveness (VE) of 2010/11 trivalent seasonal influenza vaccine (TIV) and monovalent 2009 pandemic influenza vaccine (PIV) administered in 2009/2010. The test-negative case-control study design was employed based on patients consulting primary care. Overall TIV effectiveness, adjusted for age and month, against confirmed influenza A(H1N1)pdm 2009 infection was 56% (95% CI 42-66); age-specific adjusted VE was 87% (95% CI 45-97) in <5-year-olds and 84% (95% CI 27-97) in 5- to 14-year-olds. Adjusted VE for PIV was only 28% (95% CI -6 to 51) overall and 72% (95% CI 15-91) in <5-year-olds. For confirmed influenza B infection, TIV effectiveness was 57% (95% CI 42-68) and in 5- to 14-year-olds 75% (95% CI 32-91). TIV provided moderate protection against the main circulating strains in 2010/2011, with higher protection in children. PIV administered during the previous season provided residual protection after 1 year, particularly in the <5 years age group. PMID:22691710

  8. Unusual posterior reversible encephalopathy syndrome in a case of influenza A/H1N1 infection.

    Locuratolo, Nicoletta; Mannarelli, Daniela; Colonnese, Claudio; Pauletti, Caterina; Antonaci, Laura; Ferretti, Giancarlo; Fattapposta, Francesco


    Central nervous system involvement is an uncommon though potentially a severe complication during influenza infection; the pathogenic mechanisms of the neurological syndromes described in humans are largely unknown. We describe a case of a 51-year-old man who presented with fever and behavioral changes but no focal neurological deficits. The next day, the condition rapidly evolved into a severe neurological syndrome with recurrent focal motor seizures with secondary generalization. At the brain MRI, FLAIR disclosed a slight area of increased signal in the left mesial frontal cortex extending to the frontopolar area and insula. At DWI, a mild hyperintensity was evident in the mesial-frontopolar cortex, with normal ADC values. MR perfusion was indicative of severe hypoperfusion. Fungal, bacterial and viral cultures in CSF, blood and urine were negative. The nasopharyngeal swab PCR was positive for the H1N1-influenza A virus. The patient was thus treated and by day five the neurological examination results had returned to normal. A follow-up MRI, performed two weeks later, only revealed a residual slight hyperintensity in the left medial frontal cortex. The onset of a rapidly evolving encephalopathy syndrome, its close association with a MRI brain pattern of acute vasogenic edema and favorable outcome support a diagnosis of PRES during influenza A infection. However, the topographic characteristics of the cerebral lesion seem to define a PRES with an atypical pattern. PMID:22910147

  9. Global patterns in seasonal activity of influenza A/H3N2, A/H1N1, and B from 1997 to 2005: viral coexistence and latitudinal gradients.

    Brian S Finkelman

    Full Text Available Despite a mass of research on the epidemiology of seasonal influenza, overall patterns of infection have not been fully described on broad geographic scales and for specific types and subtypes of the influenza virus. Here we provide a descriptive analysis of laboratory-confirmed influenza surveillance data by type and subtype (A/H3N2, A/H1N1, and B for 19 temperate countries in the Northern and Southern hemispheres from 1997 to 2005, compiled from a public database maintained by WHO (FluNet. Key findings include patterns of large scale co-occurrence of influenza type A and B, interhemispheric synchrony for subtype A/H3N2, and latitudinal gradients in epidemic timing for type A. These findings highlight the need for more countries to conduct year-round viral surveillance and report reliable incidence data at the type and subtype level, especially in the Tropics.

  10. Critical Clinical forms of influenza AH1N1: What we have learned from assisting the ill in Cienfuegos. Formas clínicas graves de la influenza AH1N1: Lo que hemos aprendido de la atención a estos enfermos en Cienfuegos

    Grupo Operativo Provincial de Atención Médica a los enfermos adultos hospitalizados


    Full Text Available We currently possess a growing information level on the effects of the influenza AH1N1epidemics in a range of countries in the world. Much of that information refers to statistical data and recommendations for dealing with it. Concerning the clinics of the infected, the existence of groups presenting risks of complications has been repeatedly noted in the international literature, as well as critical clinical findings, with unusual manifestations in other epidemics caused by influenza viruses. To that effect, an approach to characterize various clinical-radiological forms of that entity, as well as serious complication risk groups, may help in the early diagnose and appropriate treatment, which, undoubtedly, along with keeping preventive measures, constitute the best form of assisting the ill in the epidemic phase.
    Actualmente se cuenta con una información cada vez más abundante sobre la afectación de la epidemia de influenza A H1N1, en diversas regiones del mundo. Mucha de ella, se refiere a datos estadísticos y a recomendaciones para su enfrentamiento. En relación con la clínica de los enfermos, se ha notificado reiteradamente, en la literatura internacional, la existencia de grupos de riesgo de complicaciones, así como la presentación de cuadros clínicos graves, con manifestaciones clínicas no habituales en otras epidemias ocasionadas por los virus de la influenza. En ese sentido, una aproximación a caracterizar varias formas clínico-radiológicas de presentación de esta entidad, así como los grupos de riesgo de complicaciones graves, puede ayudar en el diagnóstico precoz y el tratamiento oportuno, que, sin dudas, junto al mantenimiento de las importantes medidas preventivas, constituyen el mejor abordaje de la asistencia a los enfermos, en la fase de la epidemia.

  11. Oseltamivir-resistant influenza A(H1N1pdm2009 strains found in Brazil are endowed with permissive mutations, which compensate the loss of fitness imposed by antiviral resistance

    Thiago Moreno Lopes e Souza


    Full Text Available The 2009 pandemic influenza A virus outbreak led to the systematic use of the neuraminidase (NA inhibitor oseltamivir (OST. Consequently, OST-resistant strains, carrying the mutation H275Y, emerged in the years after the pandemics, with a prevalence of 1-2%. Currently, OST-resistant strains have been found in community settings, in untreated individuals. To spread in community settings, H275Y mutants must contain additional mutations, collectively called permissive mutations. We display the permissive mutations in NA of OST-resistant A(H1N1pdm09 virus found in Brazilian community settings. The NAs from 2013 are phylogenetically distinct from those of 2012, indicating a tendency of positive selection of NAs with better fitness. Some previously predicted permissive mutations, such as V241I and N369K, found in different countries, were also detected in Brazil. Importantly, the change D344N, also predicted to compensate loss of fitness imposed by H275Y mutation, was found in Brazil, but not in other countries in 2013. Our results reinforce the notion that OST-resistant A(H1N1pdm09 strains with compensatory mutations may arise in an independent fashion, with samples being identified in different states of Brazil and in different countries. Systematic circulation of these viral strains may jeopardise the use of the first line of anti-influenza drugs in the future.

  12. Pandemic vaccination strategies and influenza severe outcomes during the influenza A(H1N1)pdm09 pandemic and the post-pandemic influenza season: the Nordic experience.

    Cuesta, Julita Gil; Aavitsland, Preben; Englund, Hélène; Gudlaugsson, Ólafur; Hauge, Siri Helene; Lyytikäinen, Outi; Sigmundsdóttir, Guðrún; Tegnell, Anders; Virtanen, Mikko; Krause, Tyra Grove


    During the 2009/10 influenza A(H1N1)pdm09 pandemic, the five Nordic countries adopted different approaches to pandemic vaccination. We compared pandemic vaccination strategies and severe influenza outcomes, in seasons 2009/10 and 2010/11 in these countries with similar influenza surveillance systems. We calculated the cumulative pandemic vaccination coverage in 2009/10 and cumulative incidence rates of laboratory confirmed A(H1N1)pdm09 infections, intensive care unit (ICU) admissions and deaths in 2009/10 and 2010/11. We estimated incidence risk ratios (IRR) in a Poisson regression model to compare those indicators between Denmark and the other countries. The vaccination coverage was lower in Denmark (6.1%) compared with Finland (48.2%), Iceland (44.1%), Norway (41.3%) and Sweden (60.0%). In 2009/10 Denmark had a similar cumulative incidence of A(H1N1)pdm09 ICU admissions and deaths compared with the other countries. In 2010/11 Denmark had a significantly higher cumulative incidence of A(H1N1)pdm09 ICU admissions (IRR: 2.4; 95% confidence interval (CI): 1.9-3.0) and deaths (IRR: 8.3; 95% CI: 5.1-13.5). Compared with Denmark, the other countries had higher pandemic vaccination coverage and experienced less A(H1N1)pdm09-related severe outcomes in 2010/11. Pandemic vaccination may have had an impact on severe influenza outcomes in the post-pandemic season. Surveillance of severe outcomes may be used to compare the impact of influenza between seasons and support different vaccination strategies. PMID:27123691

  13. Oseltamivir-resistant pandemic A/H1N1 virus is as virulent as its wild-type counterpart in mice and ferrets.

    Marie-Eve Hamelin

    Full Text Available The neuraminidase inhibitor oseltamivir is currently used for treatment of patients infected with the pandemic A/H1N1 (pH1N1 influenza virus, although drug-resistant mutants can emerge rapidly and possibly be transmitted. We describe the characteristics of a pair of oseltamivir-resistant and oseltamivir-susceptible pH1N1 clinical isolates that differed by a single change (H274Y in the neuraminidase protein. Viral fitness of pH1N1 isolates was assessed in vitro by determining replication kinetics in MDCK alpha2,6 cells and in vivo by performing experimental infections of BALB/c mice and ferrets. Despite slightly reduced propagation of the mutant isolate in vitro during the first 24 h, the wild-type (WT and mutant resistant viruses induced similar maximum weight loss in mice and ferrets with an identical pyrexic response in ferrets (AUC of 233.9 and 233.2, P = 0.5156. Similarly, comparable titers were obtained for the WT and the mutant strains on days 1, 3, 6 and 9 post-infection in mouse lungs and on days 1-7 in ferret nasal washes. A more important perivascular (day 6 and pleural (days 6 and 12 inflammation was noted in the lungs of mice infected with the H274Y mutant, which correlated with increased pulmonary levels of IL-6 and KC. Such increased levels of IL-6 were also observed in lymph nodes of ferrets infected with the mutant strain. Furthermore, the H274Y mutant strain was transmitted to ferrets. In conclusion, viral fitness of the H274Y pH1N1 isolate is not substantially altered and has the potential to induce severe disease and to disseminate.

  14. Systemic corticosteroids and early administration of antiviral agents for pneumonia with acute wheezing due to influenza A(H1N1pdm09 in Japan.

    Koichiro Kudo

    Full Text Available BACKGROUND: Pneumonia patients with wheezing due to influenza A(H1N1pdm09 were frequently treated with systemic corticosteroids in Japan although systemic corticosteroid for critically ill patients with pneumonia caused by influenza A(H1N1pdm09 has been controversial. Applicability of systemic corticosteroid treatment needs to be evaluated. METHODS/PRINCIPAL FINDINGS: We retrospectively reviewed 89 subjects who were diagnosed with influenza A(H1N1pdm09 and admitted to a national hospital, Tokyo during the pandemic period. The median age of subjects (45 males was 8 years (range, 0-71. All subjects were treated with antiviral agents and the median time from symptom onset to initiation of antiviral agents was 2 days (range, 0-7. Subjects were classified into four groups: upper respiratory tract infection, wheezing illness, pneumonia with wheezing, and pneumonia without wheezing. The characteristics of each group was evaluated. A history of asthma was found more frequently in the wheezing illness (55.6% and pneumonia with wheezing (43.3% groups than in the other two groups (p = 0.017. Corticosteroid treatment was assessed among subjects with pneumonia. Oxygen saturation was lower in subjects receiving corticosteroids (steroid group than in subjects not receiving corticosteroids (no-steroid group (p<0.001. The steroid group required greater oxygen supply than the no-steroid group (p<0.001. No significant difference was found by the Kaplan-Meier method between the steroid and the no-steroid groups in hours to fever alleviation from the initiation of antiviral agents and hospitalization days. In logistic regression analysis, wheezing, pneumonia and oxygen saturation were independent factors associated with using systemic corticosteroids. CONCLUSION: Patients with wheezing and a history of asthma were frequently found in the study subjects. Systemic corticosteroids together with early administration of antiviral agents to pneumonia with wheezing and

  15. Decreased serologic response in vaccinated military recruits during 2011 correspond to genetic drift in concurrent circulating pandemic A/H1N1 viruses.

    Dennis J Faix

    Full Text Available BACKGROUND: Population-based febrile respiratory illness surveillance conducted by the Department of Defense contributes to an estimate of vaccine effectiveness. Between January and March 2011, 64 cases of 2009 A/H1N1 (pH1N1, including one fatality, were confirmed in immunized recruits at Fort Jackson, South Carolina, suggesting insufficient efficacy for the pH1N1 component of the live attenuated influenza vaccine (LAIV. METHODOLOGY/PRINCIPAL FINDINGS: To test serologic protection, serum samples were collected at least 30 days post-vaccination from recruits at Fort Jackson (LAIV, Parris Island (LAIV and trivalent inactivated vaccine [TIV] at Cape May, New Jersey (TIV and responses measured against pre-vaccination sera. A subset of 78 LAIV and 64 TIV sera pairs from recruits who reported neither influenza vaccination in the prior year nor fever during training were tested by microneutralization (MN and hemagglutination inhibition (HI assays. MN results demonstrated that seroconversion in paired sera was greater in those who received TIV versus LAIV (74% and 37%. Additionally, the fold change associated with TIV vaccination was significantly different between circulating (2011 versus the vaccine strain (2009 of pH1N1 viruses (ANOVA p value = 0.0006. HI analyses revealed similar trends. Surface plasmon resonance (SPR analysis revealed that the quantity, IgG/IgM ratios, and affinity of anti-HA antibodies were significantly greater in TIV vaccinees. Finally, sequence analysis of the HA1 gene in concurrent circulating 2011 pH1N1 isolates from Fort Jackson exhibited modest amino acid divergence from the vaccine strain. CONCLUSIONS/SIGNIFICANCE: Among military recruits in 2011, serum antibody response differed by vaccine type (LAIV vs. TIV and pH1N1 virus year (2009 vs. 2011. We hypothesize that antigen drift in circulating pH1N1 viruses contributed to reduce vaccine effectiveness at Fort Jackson. Our findings have wider implications regarding

  16. The Lao Experience in Deploying Influenza A(H1N1pdm09 Vaccine: Lessons Made Relevant in Preparing for Present Day Pandemic Threats.

    Anonh Xeuatvongsa

    Full Text Available The Lao PDR, as did most countries of the Mekong Region, embarked on a pandemic vaccine initiative to counter the threat posed by influenza A(H1N1pdm09. Overall, estimated vaccine coverage of the Lao population was 14%, with uptake in targeted health care workers and pregnant women 99% and 41%, respectively. Adverse Events Following Immunization accounted for only 6% of survey driven, reported vaccination experiences, with no severe consequences or deaths. Public acceptability of the vaccine campaign was high (98%. Challenges to vaccine deployment included: 1 no previous experience in fielding a seasonal influenza vaccine, 2 safety and efficacy concerns, and 3 late arrival of vaccine 10 months into the pandemic. The Lao success in surmounting these hurdles was in large measure attributed to the oversight assigned the National Immunization Program, and national sensitivities in responding to the avian influenza A(H5N1 crisis in the years leading up to the pandemic. The Lao "lessons learned" from pandemic vaccine deployment are made even more relevant four years on, given the many avian influenza strains circulating in the region, all with pandemic potential.

  17. Use of a large general practice syndromic surveillance system to monitor the progress of the influenza A(H1N1) pandemic 2009 in the UK.

    Harcourt, S E; Smith, G E; Elliot, A J; Pebody, R; Charlett, A; Ibbotson, S; Regan, M; Hippisley-Cox, J


    The Health Protection Agency/QSurveillance national surveillance system utilizes QSurveillance®, a recently developed general practitioner database covering over 23 million people in the UK. We describe the spread of the first wave of the influenza A(H1N1) pandemic 2009 using data on consultations for influenza-like illness (ILI), respiratory illness and prescribing for influenza from 3400 contributing general practices. Daily data, provided from 27 April 2009 to 28 January 2010, were used to give a timely overview for those managing the pandemic nationally and locally. The first wave particularly affected London and the West Midlands with a peak in ILI in week 30. Children aged between 1 and 15 years had consistently high consultation rates for ILI. Daily ILI rates were used for modelling national weekly case estimates. The system enabled the 'real-time' monitoring of the pandemic to a small geographical area, linking morbidity and prescribing for influenza and other respiratory illnesses. PMID:21473803

  18. A randomized, controlled non-inferiority trial comparing A(H1N1pmd09 vaccine antigen, with and without AS03 adjuvant system, co-administered or sequentially administered with an inactivated trivalent seasonal influenza vaccine

    Langley Joanne M


    Full Text Available Abstract Background At the time of the influenza A(H1N1pmd09 pandemic it was not known if concurrent or sequential administration of seasonal trivalent influenza vaccine (TIV with pandemic vaccine was preferred. Methods Immunogenicity and safety were assessed in 871 healthy subjects aged 19–40 years who were randomised into six groups to receive co-administration or sequential administration of TIV and two doses of A(H1N1pmd09 vaccine (either unadjuvanted or adjuvanted with AS03, an α-tocopherol and squalene-based oil-in-water emulsion. Results Safety and immunogenicity data (by haemagglutination inhibition [HI] assay after each dose and six months post-Dose 1 are reported here. Co-administration of A(H1N1pmd09 vaccine with TIV reduced the HI immune responses to A(H1N1pmd09 vaccine. However, serologic responses with both co-administration and sequential schedules met the European and US regulatory criteria for pandemic and seasonal influenza vaccines up to six months following the first vaccine dose. The AS03-adjuvanted formulation elicited higher immune responses at all time points. Prior administration or co-administration of A(H1N1pmd09 vaccine did not affect immune responses to TIV. Conclusions Co-administration of TIV and A(H1N1pmd09 vaccine negatively influenced A(H1N1pmd09 vaccine immunogenicity but had no effect on TIV responses. The non-adjuvanted and adjuvanted vaccines demonstrated strong immune responses against all vaccine strains for up to six months following the first vaccine dose. Trial registration NCT00985673

  19. Synthesising evidence to estimate pandemic (2009) A/H1N1 influenza severity in 2009-2011

    Presanis, Anne M.; Pebody, Richard G.; Birrell, Paul J.; Tom, Brian D. M.; Helen K. Green; Durnall, Hayley; Fleming, Douglas; De Angelis, Daniela


    Knowledge of the severity of an influenza outbreak is crucial for informing and monitoring appropriate public health responses, both during and after an epidemic. However, case-fatality, case-intensive care admission and case-hospitalisation risks are difficult to measure directly. Bayesian evidence synthesis methods have previously been employed to combine fragmented, under-ascertained and biased surveillance data coherently and consistently, to estimate case-severity risks in the first two ...

  20. Profile of Brazilian scientific production on A/H1N1 pandemic influenza Perfil da produção científica brasileira sobre a gripe pandemica de influenza A/H1N1

    Adriana Luchs


    Full Text Available In the last few years, bibliometric studies have proliferated, seeking to provide data on world research. This study analyzes the profile of the Brazilian scientific production in the A (H1N1 influenza field between 2009 and 2011. The research was conducted in MEDLINE, SciELO and LILACS databases, selecting papers in which the term "H1N1" and "Brazil" were defined as the main topics. The data were analyzed taking into consideration the Brazilian state and institution in which the articles were produced, the impact factor of the journal and the language. The research revealed 40 documents (27 from MEDLINE, 16 from SciELO and 24 from LILACS. The journal impact factor ranged from 0.0977 to 8.1230. A similar amount of articles were written in English and Portuguese and São Paulo was the most productive state in the country, with 95% of the Brazilian production originating from the Southern and Southeastern regions. Linguistic data indicate that previous efforts made in order to improve the scientific production of Brazilian researchers making their observations attain a broader scientific audience produced results. It is necessary to assess the scientific studies, especially those conducted with public funds, in order to ensure that the results will benefit society.Nos últimos anos, estudos bibliométricos proliferaram, procurando prover dados sobre a pesquisa mundial. O presente estudo analisou o perfil da produção científica brasileira no campo da influenza A (H1N1 durante o período de 2009 a 2011. A pesquisa foi conduzida através das bases de dados Medline, SciELO e Lilacs, selecionando artigos onde os termos "H1N1" e "Brazil" foram definidos como tópicos principais. Os dados foram analisados considerando-se: o estado brasileiro e a institutição onde o trabalho foi produzido, o fator de impacto de periódico e a língua. A pesquisa revelou 40 documentos (27 provenientes do Medline, 16 do SciELO e 24 do Lilacs. O fator de impacto do peri

  1. Seasonal transmission potential and activity peaks of the new influenza A(H1N1: a Monte Carlo likelihood analysis based on human mobility

    Paolotti Daniela


    Full Text Available Abstract Background On 11 June the World Health Organization officially raised the phase of pandemic alert (with regard to the new H1N1 influenza strain to level 6. As of 19 July, 137,232 cases of the H1N1 influenza strain have been officially confirmed in 142 different countries, and the pandemic unfolding in the Southern hemisphere is now under scrutiny to gain insights about the next winter wave in the Northern hemisphere. A major challenge is pre-empted by the need to estimate the transmission potential of the virus and to assess its dependence on seasonality aspects in order to be able to use numerical models capable of projecting the spatiotemporal pattern of the pandemic. Methods In the present work, we use a global structured metapopulation model integrating mobility and transportation data worldwide. The model considers data on 3,362 subpopulations in 220 different countries and individual mobility across them. The model generates stochastic realizations of the epidemic evolution worldwide considering 6 billion individuals, from which we can gather information such as prevalence, morbidity, number of secondary cases and number and date of imported cases for each subpopulation, all with a time resolution of 1 day. In order to estimate the transmission potential and the relevant model parameters we used the data on the chronology of the 2009 novel influenza A(H1N1. The method is based on the maximum likelihood analysis of the arrival time distribution generated by the model in 12 countries seeded by Mexico by using 1 million computationally simulated epidemics. An extended chronology including 93 countries worldwide seeded before 18 June was used to ascertain the seasonality effects. Results We found the best estimate R0 = 1.75 (95% confidence interval (CI 1.64 to 1.88 for the basic reproductive number. Correlation analysis allows the selection of the most probable seasonal behavior based on the observed pattern, leading to the

  2. Mielitis transversa relacionada con vacunación anti-influenza A(H1N1

    María Florencia Arcondo


    Full Text Available La mielitis transversa es una enfermedad inflamatoria que se caracteriza por disfunción de la médula espinal. Las causas reconocidas de mielitis transversa son autoinmunes, enfermedades desmielinizantes, post infecciosas y post vacunales, aunque hasta el 50% de los casos son idiopáticas. Las vacunas contra la rubéola, paperas, rabia y gripe estacional han sido asociadas a diversos trastornos neurológicos, como el Síndrome de Guillain Barré, la encefalomielitis diseminada aguda (ADEM y la mielitis transversa. Como mecanismo preventivo luego de la pandemia de 2009, en febrero del año 2010 se inició en nuestro país la campaña de vacunación contra la Influenza A (H1N1. Se presenta el caso de una paciente con hipoestesias que aparecieron cuatro días después de haber recibido la vacuna monovalente anti-influenza A (H1N1 y progresaron con evidente nivel sensitivo. La paciente cumplía criterios diagnósticos de mielitis transversa, según el Transverse Myelitis Consortium Working Group. Tuvo remisión de las imágenes de la resonancia magnética y estabilidad clínica sin tratamiento con corticoides. Se discuten aspectos diagnósticos, pronósticos y terapéuticos de esta entidad clínica.

  3. National surveillance of pandemic influenza A(H1N1) infection-related admissions to intensive care units during the 2009-10 winter peak in Denmark: two complementary approaches

    Gubbels, S; Perner, A; Valentiner-Branth, Palle; Molbak, K


    Surveillance of 2009 pandemic influenza A(H1N1) in Denmark was enhanced during the 2009–10 winter season with a system monitoring the burden of the pandemic on intensive care units (ICUs), in order to inform policymakers and detect shortages in ICUs in a timely manner. Between week 46 of 2009 and...... week 11 of 2010, all 36 relevant Danish ICUs reported in two ways: aggregate data were reported online and case-based data on paper. Cases to be reported were defined as patients admitted to an ICU with laboratory-confirmed 2009 pandemic influenza A(H1N1) infection or clinically suspected illness after...

  4. ¿Cómo informaron los medios de comunicación sobre la influenza AH1N1 en Perú?

    Ada Palpan-Guerra


    Full Text Available Se analiza las características de las noticias emitidas por los medios de comunicación del Perú (MC sobre influenza AH1N1 en el 2013, para lo cual se revisaron diariamente los MC escritos, radio, televisión e Internet. Las noticias se clasificaron según encuadre, valoración (educativa, informativa y con elevada percepción del riesgo de contagio y muerte -NEPRCM y alcance. Se realizó un análisis descriptivo de las principales variables del estudio. El encuadre de la noticias estuvo centrado en los casos de influenza (47,5% y las acciones del MINSA/otras instituciones (29,0%. El mayor porcentaje de noticias fueron de carácter informativo (73,7%, y solo el 7,5% fueron NEPRCM; estas últimas fueron más frecuentes en los diarios (9,0% y televisión (9,4%. Durante el 2013, los MC, en general, fueron responsables al momento de informar, aunque hubo algunos que difundieron noticias que podrían haber incrementado la percepción de riesgo en la población

  5. ¿Cómo informaron los medios de comunicación sobre la influenza AH1N1 en Perú?

    Ada Palpan-Guerra


    Full Text Available Se analiza las características de las noticias emitidas por los medios de comunicación del Perú (MC sobre influenza AH1N1 en el 2013, para lo cual se revisaron diariamente los MC escritos, radio, televisión e Internet. Las noticias se clasificaron según encuadre, valoración (educativa, informativa y con elevada percepción del riesgo de contagio y muerte -NEPRCM y alcance. Se realizó un análisis descriptivo de las principales variables del estudio. El encuadre de la noticias estuvo centrado en los casos de influenza (47,5% y las acciones del MINSA/otras instituciones (29,0%. El mayor porcentaje de noticias fueron de carácter informativo (73,7%, y solo el 7,5% fueron NEPRCM; estas últimas fueron más frecuentes en los diarios (9,0% y televisión (9,4%. Durante el 2013, los MC, en general, fueron responsables al momento de informar, aunque hubo algunos que difundieron noticias que podrían haber incrementado la percepción de riesgo en la población

  6. Hospitalized cases of influenza A(H1N1pdm09 in the French territories of the Americas, July 2009-March 2010 Casos hospitalizados de gripe A(H1N1pdm09 en los territorios franceses de las Américas entre julio de 2009 y marzo de 2010

    Marie Barrau


    Full Text Available OBJECTIVE: To describe the methodology used for implementing a surveillance system specifically for influenza A(H1N1pdm09 in the French West Indies and French Guiana during an outbreak of this new virus in 2009-2010, and to report its main results. METHODS: This was an observational descriptive study of confirmed and probable cases of influenza A(H1N1pdm09 hospitalized for at least 24 hours in 23 July 2009-3 March 2010. Reverse transcription polymerase chain reaction was performed on nasopharyngeal swab samples according to the Centers for Disease Control and Prevention protocol. A probable case was defined as fever > 38ºC or aches or asthenia with respiratory symptoms (cough or dyspnea. All confirmed and probable hospitalized cases were reported, along with patient's age, sex, clinical condition at admission, place and length of hospitalization, antiviral treatment, underlying conditions, complications, and clinical evolution. A case was classified as severe if respiratory assistance or intensive care was required or if death resulted. RESULTS: A total of 331 confirmed and 16 probable cases were hospitalized, with a hospitalization rate ranging from 4.3 per 1 000 clinical cases in Saint Martin to 10.3 in French Guiana. Of these, 36 were severe, and subsequently, 10 were fatal. The median length of stay was 4 days for non-severe cases and 9 days for severe (P OBJETIVO: Describir la metodología usada para implementar un sistema de vigilancia específico para la gripe A(H1N1pdm09 en las Indias Occidentales Francesas y la Guayana Francesa durante un brote ocasionado por este virus nuevo ocurrido en 20092010 y presentar sus principales resultados. MÉTODOS: Se llevó a cabo un estudio de observación descriptivo de los casos confirmados y probables de gripe por A(H1N1pdm09 hospitalizados durante al menos 24 horas entre el 23 de julio de 2009 y el 3 de marzo de 2010. De conformidad con el protocolo de los Centros para el Control y la Prevención de

  7. Construyendo buenos ciudadanos con buenas prácticas en salud: dengue e influenza AH1N1 en Cali, Colombia

    Alejandro Arango


    Full Text Available Este artículo discute la relación entre la dimensión biológica de las enfermedades y los hábitos de auto-cuidado o “conductas saludables”. Su pregunta central indaga por cómo un fenómeno aparentemente biológico genera ciertas “buenas prácticas” en torno a la salud, defendiendo la idea de la enfermedad como un asunto socio-cultura, más que un mero hecho biológico. El estudio aquí presentado se apoya en una investigación realizada en la ciudad de Cali y enfocada en dos enfermedades, dengue e influenza AH1N1, entre 2009 y 2010. El examen de la relevancia adquirida por estas dos dolencias, mostrará cómo la biología y las prácticas de auto-cuidado tienen una estrecha relación entre sí.

  8. Personal decision-making criteria related to seasonal and pandemic A(H1N1 influenza-vaccination acceptance among French healthcare workers.

    Lila Bouadma

    Full Text Available BACKGROUND: Influenza-vaccination rates among healthcare workers (HCW remain low worldwide, even during the 2009 A(H1N1 pandemic. In France, this vaccination is free but administered on a voluntary basis. We investigated the factors influencing HCW influenza vaccination. METHODS: In June-July 2010, HCW from wards of five French hospitals completed a cross-sectional survey. A multifaceted campaign aimed at improving vaccination coverage in this hospital group was conducted before and during the 2009 pandemic. Using an anonymous self-administered questionnaire, we assessed the relationships between seasonal (SIV and pandemic (PIV influenza vaccinations, and sociodemographic and professional characteristics, previous and current vaccination statuses, and 33 statements investigating 10 sociocognitive domains. The sociocognitive domains describing HCWs' SIV and PIV profiles were analyzed using the classification-and-regression-tree method. RESULTS: Of the HCWs responding to our survey, 1480 were paramedical and 401 were medical with 2009 vaccination rates of 30% and 58% for SIV and 21% and 71% for PIV, respectively (p<0.0001 for both SIV and PIV vaccinations. Older age, prior SIV, working in emergency departments or intensive care units, being a medical HCW and the hospital they worked in were associated with both vaccinations; while work shift was associated only with PIV. Sociocognitive domains associated with both vaccinations were self-perception of benefits and health motivation for all HCW. For medical HCW, being a role model was an additional domain associated with SIV and PIV. CONCLUSIONS: Both vaccination rates remained low. Vaccination mainly depended on self-determined factors and for medical HCW, being a role model.

  9. Niños hospitalizados con neumonía por influenza AH1N11/2009 pandémico en un hospital de referencia de Perú Children hospitalized with influenza pneumonia AH1N1/2009 pandemic in the INSN

    Edwin Miranda-Choque; Carlos Ramírez; Jorge Candela-Herrera; Javier Díaz; Ana Fernández; Lenka Kolevic; Segura, Eddy R; Sonia Farfán-Ramos


    Objetivos. Determinar las características clínicas y demográficas de la neumonía por el virus de influenza AH1N1/2009 pandémico en un hospital de referencia de Perú. Materiales y métodos. Se realizó un estudio serie de casos en niños hospitalizados por neumonía por influenza AH1N1/2009 pandémico en un hospital de referencia. Revisamos las historias clínicas entre los meses de junio a septiembre 2009. Todos los casos tuvieron confirmación virológica. Resultados. Se encontró 74 casos de neumoní...

  10. International flight-related transmission of pandemic influenza A(H1N1)pdm09: an historical cohort study of the first identified cases in the United Kingdom

    Young, Nicholas; Pebody, Richard; Smith, Gillian; Olowokure, Babatunde; Shankar, Giri; Hoschler, Katja; Galiano, Monica; Green, Helen; Wallensten, Anders; Hogan, Angela; Oliver, Isabel


    Background Transporting over two billion passengers per year, global airline travel has the potential to spread emerging infectious diseases, both via transportation of infectious cases and through in-flight transmission. Current World Health Organization (WHO) guidance recommends contact tracing of passengers seated within two rows of a case of influenza during air travel. Objectives The objectives of this study were to describe flight-related transmission of influenza A(H1N1)pdm09 during a ...

  11. Multidrug resistant 2009 a/h1n1 influenza clinical isolate with a neuraminidase i223r mutation retains its virulence and transmissibility in ferrets

    E. van der Vries (Erhard); E.J.B.V. Kroeze; K.J. Stittelaar (Koert); M. Linster (Martin); A. van der Linden; E.J.A. Schrauwen (Eefje); L.M.E. Leijten (Lonneke); G. van Amerongen (Geert); M. Schutten (Martin); T. Kuiken (Thijs); A.D.M.E. Osterhaus (Albert); R.A.M. Fouchier (Ron); C.A.B. Boucher (Charles); S. Herfst (Sander)


    textabstractOnly two classes of antiviral drugs, neuraminidase inhibitors and adamantanes, are approved for prophylaxis and therapy against influenza virus infections. A major concern is that influenza virus becomes resistant to these antiviral drugs and spreads in the human population. The 2009 pan

  12. Epidemiological effects of the A(H1N1)influenza vaccine immunization program on students%中学生接种甲型H1N1流感疫苗保护效果的评价

    何寒青; 李倩; 何奔; 高雯洁; 姚凤燕; 蒋雪峰; 沈月根; 周建红; 陈恩富


    Objective To evaluate the epidemiological effects of vaccine immunization program related to A(H1N1)influenza in the middle school students.Methods Non-randomized clinical trial was designed to assess the A(H1N1)influenza vaccine on its efficacy.14883 students from 8 middle schools in Zhejiang province were recruited and classified into vaccinated or control groups,based on the status of immunization with A(H1N1)influenza vaccine.All subjects were followed up through one epidemic period(6 months)and the incidence rates of influenza-like illnesses,A(H1N1)influenza,and seasonal influenza in these two groups were compared to evaluate the efficacy of the vaccine.Results There were 6334 subjects in the vaccinated group and 8549 in the control group.7441.75 person-years were followed from these two groups.The incidence rate of A (H1N1)influenza in vaccinated group was 1.64‰ per person-year,lower than that of the control group.The rate difference(RD)was-1.64‰ per person-year(95% confidence interval value from-3.04‰ to-0.23‰ per person-year),and the difference was significant(P=0.010).The incidence rate of influenza-like illnesses in vaccinated group was 21.47‰ per person-year,lower than that of the control group(22.69‰ per person-year)and the diffefence was not significant(P>0.05).The incidence rate of B influenza in vaccinated group was 6.63‰ per person-year,higher than that of control group(7.02‰ per person-year)but the difference was not significant(P>0.05).Conclusion This vaccine demonstrated a good epidemiological effect against the A(H1N1)influenza virus infection,observed through a student-immunization program.The cross-protection effect against the influenza-like illnesses and other seasonal influenzas was not noticed in this study.%目的 了解中学生接种甲型H1NI流感疫苗的保护效果.方法 采用非随机对照临床试验方法,选择8所中学14 883名学生,分甲型H1N1流感疫苗接种组6334人,对照组(未接种)8549人,

  13. National surveillance of pandemic influenza A(H1N1) infection-related admissions to intensive care units during the 2009-10 winter peak in Denmark: two complementary approaches

    Gubbels, S; Perner, A; Valentiner-Branth, Palle; Molbak, K


    Surveillance of 2009 pandemic influenza A(H1N1) in Denmark was enhanced during the 2009–10 winter season with a system monitoring the burden of the pandemic on intensive care units (ICUs), in order to inform policymakers and detect shortages in ICUs in a timely manner. Between week 46 of 2009 and...... useful for monitoring the burden of the pandemic on ICUs....

  14. Revealing the True Incidence of Pandemic A(H1N1)pdm09 Influenza in Finland during the First Two Seasons — An Analysis Based on a Dynamic Transmission Model

    Shubin, Mikhail; Lebedev, Artem; Lyytikäinen, Outi; Auranen, Kari


    The threat of the new pandemic influenza A(H1N1)pdm09 imposed a heavy burden on the public health system in Finland in 2009-2010. An extensive vaccination campaign was set up in the middle of the first pandemic season. However, the true number of infected individuals remains uncertain as the surveillance missed a large portion of mild infections. We constructed a transmission model to simulate the spread of influenza in the Finnish population. We used the model to analyse the two first years (2009-2011) of A(H1N1)pdm09 in Finland. Using data from the national surveillance of influenza and data on close person-to-person (social) contacts in the population, we estimated that 6% (90% credible interval 5.1 – 6.7%) of the population was infected with A(H1N1)pdm09 in the first pandemic season (2009/2010) and an additional 3% (2.5 – 3.5%) in the second season (2010/2011). Vaccination had a substantial impact in mitigating the second season. The dynamic approach allowed us to discover how the proportion of detected cases changed over the course of the epidemic. The role of time-varying reproduction number, capturing the effects of weather and changes in behaviour, was important in shaping the epidemic. PMID:27010206

  15. Surveillance of influenza A(H_1N_1)in Hangzhou city in 2009%2009年杭州市甲型H_1N_1流感监测现状分析

    刘社兰; 谢立; 杨旭辉; 孙昼; 王婧; 程瑾; 黄仁杰; 缪凡; 阮冰; 邓晶


    目的 探讨2009年杭州市甲型H_1N_1流感的流行规律、临床表现和病原学特征.方法 对2009年杭州市13家流感监测哨点医院的每日门诊流感样病例和甲型H_1N_1流感确诊病例的流行病学进行分析.采用RT-PCR方法对咽拭子中血凝素(HA)基因进行扩增和测序,并用DNASTAR软件进行序列分析.全文数据采用SPSS 12.0软件进行统计分析.率的比较采用x~2检验.结果 流感样病例监测显示,第28周之前,疫情处于平稳状态,之后全市流感样病例逐渐增多.第35周时达到高峰,全市流感样病例就诊比例为7.47%(5442/72859).之后疫情回落,但到第41周时又再次回升,至第46周出现第二次高峰,全市流感样病例就诊比例达到11.32%(11034/97436).第38周以前,杭州市人群中主要流行株是季节性H_3N_2型,其次有少量的乙型和季节性流感H_1N_1型,到第44周,甲型H_1N_1流感成为唯一的优势流行株,主要易感人群是11-25岁的青少年,以学生居多.序列分析显示,2009年杭州市甲型H_1N_1流感病毒株与北美株、中国其他地区的毒株以及疫苗株同源性达到99%,关键位点高度保守,但与季节性流感病毒株同源性只有70%.结论 2009年杭州市流感疫情发展迅速,人群中流行的优势毒株为甲型流感H_1N_1型,易感人群为青少年,目前未发现变异株及高致病株,但仍需进一步监测.%Objective To investigate the epidemiological,clinical and etiological features of influenza/influenza A(H_1N_1)in Hangzhou city in 2009.Methods Epidemiological data of patients with influeliza-1ike illness or influenza A(H_1N_1)from 13 sentinel hospitals in Hangzhou(2009)were analyzed.Hemagglutinin(HA)genes of H_1N_1 subtype influenza virus were amplified by RT-PCR and the sequence analysis were performed by DNAsTAR.SPSS 12.0 software was used for data processing and chi-square test was performed for difference comparison of rates.Results Epidemic cunre for influenza

  16. Real-time estimation of the hospitalization fatality risk of influenza A(H1N1)pdm09 in Hong Kong.

    Wong, J Y; Wu, P; Lau, E H Y; Tsang, T K; Fang, V J; Ho, L-M; Cowling, B J


    During the early stage of an epidemic, timely and reliable estimation of the severity of infections are important for predicting the impact that the influenza viruses will have in the population. We obtained age-specific deaths and hospitalizations for patients with laboratory-confirmed H1N1pdm09 infections from June 2009 to December 2009 in Hong Kong. We retrospectively obtained the real-time estimates of the hospitalization fatality risk (HFR), using crude estimation or allowing for right-censoring for final status in some patients. Models accounting for right-censoring performed better than models without adjustments. The risk of deaths in hospitalized patients with confirmed H1N1pdm09 increased with age. Reliable estimates of the HFR could be obtained before the peak of the first wave of H1N1pdm09 in young and middle-aged adults but after the peak in the elderly. In the next influenza pandemic, timely estimation of the HFR will contribute to risk assessment and disease control. PMID:27125572

  17. Maternal and neonatal outcomes among pregnant women with 2009 pandemic influenza A(H1N1 illness in Florida, 2009-2010: a population-based cohort study.

    Timothy J Doyle

    Full Text Available INTRODUCTION: Pregnant women have been identified as a high risk group for severe illness with 2009 pandemic influenza A(H1N1 virus infection (pH1N1. Obesity has also been identified as a risk factor for severe illness, though this has not been thoroughly assessed among pregnant women. The objectives of this study were to provide risk estimates for adverse maternal and neonatal outcomes associated with pH1N1 illness during pregnancy and to assess the role of obesity in these outcomes. METHODS: We established a retrospective population-based cohort of all live births occurring in Florida during the first 15 months of the pandemic. Illness with pH1N1 during pregnancy was ascertained through record linkage with the Florida state notifiable disease surveillance database. Data from the birth record, including pre-pregnancy body mass index, were analyzed to assess risk of adverse outcomes associated with pH1N1 illness. RESULTS: A total of 194 women were identified through surveillance with pH1N1 illness during pregnancy. Children born to women with pH1N1 illness during pregnancy were at increased risk for low birth weight [OR (95%CI: 1.78 (1.11-2.860], premature birth [2.21 (1.47-3.330], and infant death [4.46 (1.80-11.00], after adjusting for other factors. Women with pH1N1 illness during pregnancy were at increased risk for severe outcomes including admission to an intensive care unit. Obesity was an observed risk factor, both for the more severe pH1N1 illness detected through surveillance, and for severe maternal outcomes. CONCLUSIONS: Case-patients in this analysis likely represent the most severely ill subset of all women infected with pH1N1 during pregnancy, limiting the generalizability of these findings to more severely ill patients rather than influenza infection in general. Nevertheless, these results suggest that more severe pH1N1 illness during pregnancy is associated with adverse neonatal outcomes and that pregnant women should continue

  18. Clinical analysis of 65 cases of A(H1N1)influenza complicated with pulmonary infection%甲型H1N1流感并发肺部感染65例临床分析

    郭云波; 马希涛; 杨志刚


    Objective To understand clinical features,chest-image characteristics and treatment of A(H1 N1)influenza complicated with pulmonary infection,improve the clinicians a better understanding of this disease.Methods A total of 65 patients with A(H1N1) referred to Henan,China were studied retrospectively.The reviewed data included clinical manifestations,Routine blood test,chest-image characteristics and treatment.Results The 65 patients were collected:31 men and 34 women.Of the 65 cases,19 cases were maternal.The main clinical manifestations of influenza-like symptoms included fever(65 cases),cough (64 cases),expectoration (53 cases),sore throat (40 cases),diarrhea (6 ca-ses).Routine blood test WBC revealed normal in 51 patients,and WBC count decreased in 16 patients and increased in 8 patients.Neutrophil count normal in 29 patients,decreased in 13 patients and increased in 23 patients.In the initial chest-image of 65 patients the main abnormal appearance was ground-glass opacification 65 cases,with consolidation in 32 cases,11 cases of malignant pleural effusion with.Bilateral lesions in 52 cases,right lung lesion in 8 cases,left lung lesions in 5 cases ; recovery stage lesions,except for 6 patient deaths,cord-like,reticular shadows in 46 cases,8 cases had no obvious changes,5 cases were completely absorbed.A total of 19 patients using ventilator assisted breathing.Application of oseltamivir in 65 cases,combined application of antibiotics in 65 cases,8 cases of immune serum virus.61 cases were cured,6 cases died,3 cases of maternal death cases.Conclusions ①A (H1 N1) influenza is highly infectious,easily complicated with pulmonary infection; ②Influenza a H1N1 influenza maternal is at-risk group,and the critical condition of the patient,severe morbidity and mortality significantly higher than other groups; ③Pulmonary disease spread to more than bilateral pulmonary lesions,radiological patch shadow,consolidation images and other manifestations of mixed,the slow

  19. Comparison of epidemiological characteristics of type AH1N1 influenza and seasonal influenza in Luwan District,Shanghai%上海市卢湾区甲型H1N1流感与季节性流感流行特征比较分析

    陆璐; 宋黎黎; 郦佳莹; 袁家麟; 贾晓东; 程华; 康来仪; 姜庆五


    Objective To compare the epidemicological characteristics of type AH1N1 influenza and seasonal influenza and to provide scientific basis on interventions. Methods The pathogen surveillance data of flu surveillance sentinel hospital of Luwan District from July 2009 to November 2011 was collected. We calculated 519 surveillance cases by age, year, month and week. In October 2011, we selected a probability sample of 200 residents of Luwan District. For each subject we measured HI antibody of influenza. Results In 2009, type AH1N1 accounted for the highest positive rate of 30%. In 2010, type AH3 accounted for the highest positive rate of 13% , followed by type BV with positive rate as 12%. In 2011, type AH1N1 accounted for the highest positive rate of 12% , followed by type BV with positive rate as 11%. Type AH1N1 became epidemic mainly in winter, type AH3 became epidemic mainly in summer, type BV mainly in spring. The whole population had relatively high antibody levels of type BY and AH1 with their geometric mean titer of antibody accounted for 1:918 and 1:897 respectively, while the antibody levels of type BV, AH3 and AH1N1 were relatively low with their geometric mean titer of antibody accounting for 1:625 , 1:599 and 1:120 respectively. The antibody level of type AH1N1 was significantly lower than that of other subtypes of influenza for the whole population. Conclusions Vaccine components should continue including type AH3, AH1N1 and BV strain components.%目的 比较甲型H1N1流感与季节性流感流行特征,为制定干预措施提供科学依据.方法 对卢湾区2009年7月~2011年11月流感监测病例进行分析,并于2011年10月对卢湾区200名居民进行流感HI抗体检测.结果 2009年,AH1N1阳性率最高,为30%;2010年,AH3、BV阳性率较高,分别为13%和12%;2011年,AH1N1、BV阳性率较高,分别为12%和11%.AH1N1流行季节主要为冬季,AH3主要为夏季,BV主要为春季.全人群BY和AH1抗体滴度较高,分别为1

  20. Severe acute respiratory infections during the influenza A(H1N1)2009 pandemic in Belgium: first experience of hospital-based flu surveillance


    Introduction In September 2009, as part of the surveillance during the Influenza A(2009) pandemic, Bel-gium introduced a web-based surveillance system aimed at recording hospitalisations and deaths attributable to Influenza in real time. Methods We present the web-based application developed for the pandemic as well as a descriptive analysis of Severe Acute Respiratory Infection (SARI) cases reported through this system. Results From 1 September to 31 December 2009, 1723 SARI-related hospitalisations potentially due to influenza were reported in Belgium. The median age of the patients was 29 years (range: < 1 year-99 years). Among SARI-hospitalised patients 68% were aged less than 45 years, 10.6% were vaccinated with the seasonal influenza vaccine and 7.5% with the pandemic influenza vaccine. No deaths were recorded. Conclusions This first experience showed the feasibility of getting real-time information from hospitals during a public health crisis. However, the absence of death detected through the system highlighted the importance of better defining the severity of the hospital cases.

  1. Caso Anatomopatológico influenza AH1N1 en una paciente embarazada: características clínicas y patológicas

    José Luis Quirós Alpízar


    Full Text Available Se decriben los hallazgos clínicos y patológicos de la infección por influenza A (H1 N1, basados en un caso de autopsia. La paciente, una mujer de 25 años embarazada de gemelos, con 33 semanas de gestación y síntomas similares a influenza, quien fue admitida en el hospital y murió 13 días después. En la autopsia, el principal hallazgo fue daño alveolar difuso en fase proliferativa.We describe the pathologic and clinical changes over a case of Influenza A (H1N1 infection based in autopsy findings. The patient was a 25 year-old female pregnant of 33 weeks gestation twins, who had flu-like symptoms. She was hospitalized, but died 13 days after admitting. Autopsy findings included a diffuse alveolar damage in a proliferative phase.

  2. Early spread of the 2009 influenza A(H1N1) pandemic in the United Kingdom--use of local syndromic data, May-August 2009.

    Smith, S; Smith, G E; Olowokure, B; Ibbotson, S; Foord, D; Maguire, H; Pebody, R; Charlett, A; Hippisley-Cox, J; Elliot, A J


    Following the confirmation of the first two cases of pandemic influenza on 27 April 2009 in the United Kingdom (UK), syndromic surveillance data from the Health Protection Agency (HPA)/QSurveillance and HPA/NHS Direct systems were used to monitor the possible spread of pandemic influenza at local level during the first phase of the outbreak. During the early weeks, syndromic indicators sensitive to influenza activity monitored through the two schemes remained low and the majority of cases were travel-related. The first evidence of community spread was seen in the West Midlands region following a school-based outbreak in central Birmingham. During the first phase several Primary Care Trusts had periods of exceptional influenza activity two to three weeks ahead of the rest of the region. Community transmission in London began slightly later than in the West Midlands but the rates of influenza-like illness recorded by general practitioners (GPs) were ultimately higher. Influenza activity in the West Midlands and London regions peaked a week before the remainder of the UK. Data from the HPA/NHS Direct and HPA/QSurveillance systems were mapped at local level and used alongside laboratory data and local intelligence to assist in the identification of hotspots, to direct limited public health resources and to monitor the progression of the outbreak. This work has demonstrated the utility of local syndromic surveillance data in the detection of increased transmission and in the epidemiological investigation of the pandemic and has prompted future spatio-temporal work. PMID:21262185

  3. Management of the 2009 A/H1N1 influenza pandemic in patients with hematologic diseases: a prospective experience at an Italian center.

    Girmenia, Corrado; Mercanti, Caterina; Federico, Vincenzo; Rea, Massimiliano; De Vellis, Annalisa; Valle, Veronica; Micozzi, Alessandra; Latagliata, Roberto; Breccia, Massimo; Morano, Salvatore Giacomo; Brunetti, Gregorio Antonio; Sali, Michela; Delogu, Giovanni; Foà, Robin; Alimena, Giuliana; Gentile, Giuseppe


    Data derived from epidemiologic surveillance adopted at our center in hematologic and stem cell transplant patients during the 2009 influenza A (H1N1)v pandemic are reported. Of the 52 patients with influenza-like disease we observed, 37 underwent a real-time PCR evaluation and 21 had a confirmed diagnosis. Of the RT-PCR-confirmed cases, 23.8% were children (age 65 years; 47.6% presented with a pulmonary infiltrate and 33.3% with respiratory failure. Pulmonary involvement was observed more frequently in patients with comorbidities. All patients received a course of oseltamivir therapy starting an average of 1 day (range <1-2) after the onset of symptoms. No patient was transferred to the intensive care unit. The viral disease had a generally favorable outcome despite the high frequency of pulmonary involvement. A prompt clinical evaluation with an early antiviral and supportive therapy may have played a beneficial role in the outcome. PMID:21411983

  4. 北京市顺义区健康人群甲型H1N1流感抗体水平监测%Serologic survey on influenza A(H1N1) in Shunyi district of Beijing

    冯冉; 王凤双; 肖雷; 吴殚; 唐莹; 高建华


    目的:了解北京市顺义区健康人群甲型H1N1流感抗体水平,为卫生部门制定预防控制措施和策略提供依据.方法:随机选取顺义区12个乡街的5岁以上健康人群采集免疫前静脉血检测抗体,评估健康人群抗体水平.结果:202份血清标本中甲流抗体水平阳性率46.53% (94/202),与北京市人群甲型H1N1流感抗体水平检测结果差异有统计学意义.抗体几何平均滴度倒数(GMRT)为32.78.不同性别人群之间甲型H1N1流感抗体阳性率无差别(P>0.05),不同年龄组之间抗体水平阳性率有差别(P<0.05),25岁~29岁、10岁~14岁组抗体水平阳性率高.结论:顺义区甲型H1N1流感实际感染数高于北京市甲型H1N1流感平均感染水平.甲型H1N1流感感染与性别无关,与年龄有关,感染主要集中在25岁~ 29岁、10岁~14岁组人群.%Objective:To know the antibody levels against influenza A(H1N1 ) in Shunyi district of Beiing, to provide a scientific evidence for related departments to make the prevention and control strategies of influenza A (H1N1). Methods: Venous blood was randomly collected from healthy population above 5 years old in 12 towns and streets of Shunyi district to analyze the antibody levels against A(H1N1 ). Results: Among 202 serum specimens, the positive rate of influenza A(H1N1 ) antibody was 46. 53% (94/202) , which had statistical significance with that of Beijing. The GMRT was 32. 78. The positive rate difference of influenza A( H1N1 ) antibody was not found between males and females(P>0.05) , while which was found among different groups(P <0. 05). Higher positive rate was found in population aged 25 ~29 and 10 ~ 14 years old. Conclusion-. Influenza A( H1N1) infection cases in Shunyi district were more than the average of Beijing, which was not related to sex but age, especially in people of 25 ~ 29 and 10 ~ 14 years old.

  5. Genetic diversity among pandemic 2009 influenza viruses isolated from a transmission chain

    Fordyce, Sarah L; Bragstad, Karoline; Pedersen, Svend Stenvang; Jensen, Thøger Gorm; Gahrn-Hansen, Bente; Daniels, Rod; Hay, Alan; Kampmann, Marie-Louise; Bruhn, Christian Aw; Moreno-Mayar, J Victor; Avila Arcos, Maria del Carmen; Gilbert, M Thomas P; Nielsen, Lars P


    Influenza viruses such as swine-origin influenza A(H1N1) virus (A(H1N1)pdm09) generate genetic diversity due to the high error rate of their RNA polymerase, often resulting in mixed genotype populations (intra-host variants) within a single infection. This variation helps influenza to rapidly...

  6. Compliance to oseltamivir among two populations in Oxfordshire, United Kingdom affected by influenza A(H1N1pdm09, November 2009--a waste water epidemiology study.

    Andrew C Singer

    Full Text Available Antiviral provision remains the focus of many pandemic preparedness plans, however, there is considerable uncertainty regarding antiviral compliance rates. Here we employ a waste water epidemiology approach to estimate oseltamivir (Tamiflu® compliance. Oseltamivir carboxylate (oseltamivir's active metabolite was recovered from two waste water treatment plant (WWTP catchments within the United Kingdom at the peak of the autumnal wave of the 2009 Influenza A (H1N1pdm09 pandemic. Predictions of oseltamivir consumption from detected levels were compared with two sources of national government statistics to derive compliance rates. Scenario and sensitivity analysis indicated between 3-4 and 120-154 people were using oseltamivir during the study period in the two WWTP catchments and a compliance rate between 45-60%. With approximately half the collected antivirals going unused, there is a clear need to alter public health messages to improve compliance. We argue that a near real-time understanding of drug compliance at the scale of the waste water treatment plant (hundreds to millions of people can potentially help public health messages become more timely, targeted, and demographically sensitive, while potentially leading to less mis- and un-used antiviral, less wastage and ultimately a more robust and efficacious pandemic preparedness plan.

  7. Analysis on the epidemiological and clinical characteristics of 190 cases with A(H1N1)influenza in Lhasa%拉萨190例甲型H1N1流感的流行病学特点及临床分析

    龚学红; 王毅; 张小林; 索朗卓玛


    目的 探讨2009年拉萨甲型H1N1流感的流行病学特征及临床特点.方法 对2009年9-12月我院收治的190例甲型H1N1流感确诊病例的流行病学、临床表现及实验室检查等资料进行回顾性分析.结果本次拉萨地区暴发的甲型H1N1流感主要发生在秋冬季,9、10月为高峰.190例病例中,男性106例(55.79%),女性84例(44.21%),患者的平均年龄(16.66±9.78)岁,以7~17岁为主,学生139例(73.16%),藏族144例(75.79%).临床表现以发热、咳嗽、咽痛、咽充血和扁桃体肿大为主,172例有发热(90.53%).所有病例均未接种过甲型H1N1流感疫苗,入院时甲型H1N1流感病毒核酸检测均为阳性,176例(92.63%)病毒快速检测阳性.174例(91.58%)使用利巴韦林等抗病毒治疗取得较好疗效,184例痊愈出院,无死亡病例.结论 本组患者均为易感人群,因此流行期间接种甲型流感疫苗,提高人群免疫力势在必行.%Objective To investigate the epidemiological and clinical features of 190 A(H1N1)influenza cases in 2009 Lhasa.Methods 1he clinical data of 190 hospitalized cases with A(H1N1)influenza in our hospital from September to December 2009 were collected and retrospectively analyzed in epidemiology,clinical features and laboratory test.Results This outbreak of A(H1N1)influenza in Lhasa occurred during autumn and winter with the peak period in September and October.Of the 190 cases,there were 106(55.79%)males,84(44.21%)females.The average age was(16.66±9.78)years old,most of the cases were 7-17 years old.139(73.16%)cases were students.144(75.79%)cases were Tibetan people.The main clinical manifestations were fever,cough,pharyngalgia,pharyngitis,tonsillitis,and172(90.53%)cases had fever.No vaccination was implemented in all the patients before,all of them were positive for the A(H1N1)influenza virus nucleic acid testing on admission,176(92.63%)cases were positive for rapid detection of A influenza virus,174(91.58%)cases accepted ribavirin and

  8. Ethnicity, deprivation and mortality due to 2009 pandemic influenza A(H1N1) in England during the 2009/2010 pandemic and the first post-pandemic season.

    Zhao, H; Harris, R J; Ellis, J; Pebody, R G


    The relationship between risk of death following influenza A(H1N1)pdm09 infection and ethnicity and deprivation during the 2009/2010 pandemic period and the first post-pandemic season of 2010/2011 in England was examined. Poisson regression models were used to estimate the mortality risk, adjusted for age, gender, and place of residence. Those of non-White ethnicity experienced an increased mortality risk compared to White populations during the 2009/2010 pandemic [10·5/1000 vs. 6·0/1000 general population; adjusted risk ratio (RR) 1·84, 95% confidence interval (CI) 1·39-2·54] with the highest risk in those of Pakistani ethnicity. However, no significant difference between ethnicities was observed during the following 2010/2011 season. Persons living in areas with the highest level of deprivation had a significantly higher risk of death (RR 2·08, 95% CI 1·49-2·91) compared to the lowest level for both periods. These results highlight the importance of rapid identification of groups at higher risk of severe disease in the early stages of future pandemics to enable the implementation of optimal prevention and control measures for vulnerable populations. PMID:25850904

  9. Ameaça e controle da gripe A(H1N1: uma análise discursiva de Veja, IstoÉ e Época Threat and control of influenza A (H1N1: a discursive analysis of Brazilian magazines Veja, IstoÉ and Época

    Isaltina Maria de Azevedo Mello Gomes


    differentiated 'new edition' of flu, due to the identification of a new subtype of influenza virus that could be as lethal as the old one. A similar fear to what had been experienced also with avian influenza in 1997, prompting officials to remain on alert. This article aims to evaluate the production of news on influenza A(H1N1 in the three main national magazines in Brazil. We chose to analyze the eigth covers of magazines Veja, IstoÉ and Época published during the first months of the pandemic, in the beginning of 2009. Based on concepts of Discourse Analysis and Journalism Theory, the analysis indicates that the news can be divided into two phases, focusing initially on the alarm over the fear of new virus and deaths recorded and afterwards on the control due to the finding that the disease presented less risk than previously thought and to the actions taken to fight it.

  10. 温州市首次甲型H1N1流感流行的特征分析%Characteristics analysis on the first epidemic of influenza A(H1N1)in Wenzhou

    周祖木; 蔡圆圆; 魏晶娇; 陈晟; 潘琼娇; 马洪波


    Objective To analyse the epidemiological characteristics of the first influenza A (H1N1) epidemic in Wenzhou and provide a scientific basis for the measures on control and prevention of influenza. Methods A descriptive epidemiological method was used for analysis of influenza A (H1N1) case data in Wenzhou from May 2009 to July 2010. Results There were 4164 cases (accumulative incidence 53.94/100 000) of influenza A (H1N1) in Wenzhou between May 2009 and July 2010. The peak of incidence was from October 2009 to January 2010, there were 3825 cases, accounted for 91.86%. The patients occurred in eleven counties(districts) of Wenzhou. Most of the cases were found in Lucheng, Ruian and Yueqing counties (districts). Cases for groups aged 5-19 years accounted for 67.39% (2806 The influenza A (H1N1) is gradually transmitted from urbans to rural areas after first imported case is introduced to Wenzhou. The incidence rate is closely related to density of population and mobility of population. Schools are risk sellings for transmissions of influenza A (H1N1). It is very critical to strengthen the epidemiological surveillance for influenza in schools. The influenza A (H1N1) vaccination is specific measures for the prevention of influenza A(H1N1) and gained apparent effectiveness.%目的 分析温州市首次甲型H1N1流感流行特征,为防控措施提出建议.方法 用描述性流行病学方法,对温州市2009年5月至2010年7月甲型H1N1流感病例个案资料进行分析.结果 2009年5月至2010年7月共报告甲型H1N1流感病例4164例,累积发病率53.94/10万.2009年10月至2010年1月为发病高峰,共报告病例数3825例,占总病例数的91.86%.11个县(市、区)均有病例发生,病例数居前三位的是鹿城区、瑞安市和乐清市.5~19岁年龄组共2806例,占总病例数的67.39%,男女之比为1.25∶1;学生占总病例数的66.11%.213例重症与危重症病例中以散居儿童和学生最多,共91例,占42.72%.结论 输入性病

  11. Swine flu. Mexico's handling of A/H1N1 in comparative perspective.

    Ear, Sophal


    Emerging infectious diseases (EIDs) pose international security threats because of their potential to inflict harm upon humans, crops, livestock, health infrastructure, and economies. Despite the scale of this threat, there are inherent limitations in preventing and controlling EIDs, including the scope of current disease surveillance efforts. All of this leads to the following questions in the context of Mexico's recent swine flu experience: What were the cultural, political, and economic challenges to Influenza A/H1N1 virus response in Mexico? By way of comparison, what can we learn from the U.S. experience in 1976 with A/New Jersey/76 (Hsw1N1), later referred to as H1N1? This article explores the comparative political economy of Mexico's handling of influenza virus A/H1N1 outbreak in 2009. Research provides notable observations-based on the strengths and weaknesses of each country's response--that can be used as a starting point of discussion for the design of effective EIDs surveillance programs in developing and middle-income countries. In the U.S., the speed and efficiency of the 1976 U.S. mobilization against H1N1 was laudable. Although the U.S. response to the outbreak is seldom praised, the unity of the scientific and political communities demonstrated the national ability to respond to the situation. Mexico's strongest characteristics were its transparency, as well as the cooperation the country exhibited with other nations, particularly the U.S. and Canada. While Mexico showed savvy in its effective management of public and media relations, as the article details, political, economic, and cultural problems persisted. PMID:23379315


    I. Manini


    Full Text Available On April 24, 2004, the World Health Organization confirmed a number of cases of con- tagion of the new Influenza virus A/HIN1 in Mexico and the United States. On June 11 2009, the rapid spread of infection compelled the WHO to raise the pandemic phase to 6, which corresponds to the highest state of alert. The virus probably originated from a recent reassortment between a swine virus previously reassorted with three different viral strains (swine, avian, human and a new viral strain similar to the Eu- roasiatic avian virus[1]. This unprecedented circulation of the new influenza virus was facilitated by travel and international exchanges and has reached, in the period of little more than six weeks, the same extent that had been present in previous pandemics in a period of six months, therefore making necessary the implementation of various strategies of Epidemiological and Virological Surveillance. During the pandemic sea- son, 866 pharyngeal swab samples of persons who presented influenza symptoms were gathered. The patients were then divided into different age groups: 0-4, 5-24, 35-54, 55-64 and ≥65 years of age. The virus’ RNA was extracted from each swab by using a specific kit. Afterwards the RNA was reverse transcribed in cDNA and ampli- fied in a single reaction of real-time PCR using the one-step kit recommended by CDC protocol. The analysis of the 866 pharyngeal swabs has shown the presence of 262 positive sample results for the new variant of the A/H1N1virus. Several parameters of this study have been taken in consideration: age groups, geographical distribution of infection in the three cities studied, the weekly trend of positive results which had shown up after a trip abroad, the incidence in local cases and the measure of infection of the virus among patients who came in contact with infected persons. Among the examined age groups, those majorly affected are: ages 0-4, 5-14, 15-24, the least affected age group was ≥65. In

  13. Learning to trust flu shots: quasi-experimental evidence on the role of learning in influenza vaccination decisions from the 2009 influenza A/H1N1 (swine flu) pandemic

    Maurer, J.; Harris, K M


    This paper studies consumer learning in influenza vaccination decisions, i.e., potential causal effects of past experiences of being vaccinated on current use of influenza vaccine. Existing structural models of demand usually identify consumer learning parametrically based on functional form assumptions within dynamic forward-looking Bayesian demand models. To the best of our knowledge, we are the first to explore the potential role of consumer learning in pharmaceutical demand within a reduc...

  14. Canadian family physicians' and paediatricians' knowledge, attitudes and practices regarding A(H1N1 pandemic vaccine

    Bettinger Julie A


    Full Text Available Abstract Background One of the main determinants of public immunization success is health professionals' support and recommendations. Little is known about the physicians' level of support and intentions regarding A(H1N1 pandemic influenza vaccination. The aim of this survey was to document Canadian family physicians' and paediatricians' knowledge, attitudes and practices (KAP as well as their intentions regarding A(H1N1 pandemic influenza vaccines right before the beginning of the largest immunization campaign in Canadian history. Findings A self-administered, anonymous, mail-based questionnaire was sent to a random sample of family physicians and to all paediatricians practicing in Canada. All 921 questionnaires received by October 29 2009 were included in the analysis. Between 72% and 92% of respondents agreed with the statements regarding vaccine safety, effectiveness and acceptability. More than 75% of respondents intended to recommend the A(H1N1 pandemic influenza vaccine to their patients and to get vaccinated themselves. The most significant factors associated with the intention to recommend A(H1N1 pandemic vaccines were physicians' intention to be vaccinated against influenza themselves and the perceived acceptability of the vaccine by the vaccinators. Conclusions Most Canadian family physicians and paediatricians surveyed were supportive of the A(H1N1 pandemic influenza vaccination before its implementation and large media coverage.

  15. Global migration of influenza A viruses in swine

    The emergence of the 2009 A/H1N1 pandemic virus underscores the importance of understanding how influenza A viruses evolve in swine on a global scale. To reveal the frequency, patterns and drivers of the spread of swine influenza virus globally, we conducted the largest phylogenetic analysis of swin...

  16. Quantifying homologous and heterologous antibody titre rises after influenza virus infection.

    Freeman, G; Perera, R A P M; Ngan, E; Fang, V J; Cauchemez, S; Ip, D K M; Peiris, J S M; Cowling, B J


    Most influenza virus infections are associated with mild disease. One approach to estimate the occurrence of influenza virus infections in individuals is via repeated measurement of humoral antibody titres. We used baseline and convalescent antibody titres measured by haemagglutination inhibition (HI) and viral neutralization (VN) assays against influenza A(H1N1), A(H3N2) and B viruses to investigate the characteristics of antibody rises following virologically confirmed influenza virus infections in participants in a community-based study. Multivariate models were fitted in a Bayesian framework to characterize the distribution of changes in antibody titres following influenza A virus infections. In 122 participants with PCR-confirmed influenza A virus infection, homologous antibody titres rose by geometric means of 1·2- to 10·2-fold after infection with A(H1N1), A(H3N2) and A(H1N1)pdm09. Significant cross-reactions were observed between A(H1N1)pdm09 and seasonal A(H1N1). Antibody titre rises for some subtypes and assays varied by age, receipt of oseltamivir treatment, and recent receipt of influenza vaccination. In conclusion, we provided a quantitative description of the mean and variation in rises in influenza virus antibody titres following influenza virus infection. The multivariate patterns in boosting of antibody titres following influenza virus infection could be taken into account to improve estimates of cumulative incidence of infection in seroepidemiological studies. PMID:27018720

  17. Evaluation of MChip with Historic Subtype H1N1 Influenza A Viruses, Including the 1918 “Spanish Flu” Strain▿

    Moore, Chad L.; Smagala, James A.; Smith, Catherine B.; Dawson, Erica D.; Cox, Nancy J.; Kuchta, Robert D.; Rowlen, Kathy L.


    The robustness of a recently developed diagnostic microarray for influenza, the MChip, was evaluated with 16 historic subtype H1N1 influenza A viruses (A/H1N1), including A/Brevig Mission/1/1918. The matrix gene segments from all 16 viruses were successfully detected on the array. An artificial neural network trained with temporally related A/H1N1 viruses identified A/Brevig Mission/1/1918 as influenza virus A/H1N1 with 94% probability. PMID:17855577

  18. Evaluation of MChip with Historic Subtype H1N1 Influenza A Viruses, Including the 1918 “Spanish Flu” Strain▿

    Moore, Chad L.; Smagala, James A.; Smith, Catherine B.; Dawson, Erica D.; Cox, Nancy J.; Kuchta, Robert D.; Rowlen, Kathy L.


    The robustness of a recently developed diagnostic microarray for influenza, the MChip, was evaluated with 16 historic subtype H1N1 influenza A viruses (A/H1N1), including A/Brevig Mission/1/1918. The matrix gene segments from all 16 viruses were successfully detected on the array. An artificial neural network trained with temporally related A/H1N1 viruses identified A/Brevig Mission/1/1918 as influenza virus A/H1N1 with 94% probability.

  19. 2009 Pandemic Influenza A Virus Subtype H1N1 in Morocco, 2009–2010: Epidemiology, Transmissibility, and Factors Associated With Fatal Cases

    Barakat, Amal; Ihazmad, Hassan; El Falaki, Fatima; Tempia, Stefano; Cherkaoui, Imad; El Aouad, Rajae


    Background. Following the emergence of 2009 pandemic influenza A virus subtype H1N1 (A[H1N1]pdm09) in the United States and Mexico in April 2009, A(H1N1)pdm09 spread rapidly all over the world. There is a dearth of information about the epidemiology of A(H1N1)pdm09 in Africa, including Morocco. We describe the epidemiologic characteristics of the A(H1N1)pdm09 epidemic in Morocco during 2009–2010, including transmissibility and risk factors associated with fatal disease.

  20. 不同专业大学生甲型H1N1流感知识及行为调查%Influenza A(H1N1)-related knowledge and behaviors among university students with different majors in Guangzhou

    顾菁; 陈培奋; 林羽媚; 刘德辉; 葛菲雪; 凌文华


    Objective To investigate influenza A( H1N1 )-related knowledge and behaviors among university students and to provide information for influenza A( H1N1 ) epidemic prevention in campus.Methods A total of 873 students from three different majors of two universities in Guangzhou were recruited.Anonymous self-administered questionnaire was used to collect data.Univariate and multivariate logistic regression model were used in the analysis.Results University students had some awareness of the transmission route and preventive measure of influenza A ( H1N1 ) (39.2% -96.8% ).But many of them did not have preventive behavior (23.9% -57.7% ).After adjusting for significant background factors, students majoring in public health knew more about influenza A( H1N1 )-related transmission route compared with those majoring in anthropology or social work( odds ratio = 2.5 - 5.2 ,P < 0.01 ).There was no significant difference in influenzaA( H1N1 ) related preventive behavior among students with different majors.Over 70% of the students reported that they had insufficient information to prevent influenza A(H1N1 ).Conclusion The condition of influenza A(H1N1 ) prevention in campus is far from requirment.Improvement in preventive perception and behavior is greatly needed among university students.%目的 了解不同专业大学生甲型H1N1流感相关知识和行为情况,为预防和控制校园内甲型H1N1流感疫情提供参考依据.方法 采用自行设计调查问卷,对广东省广州市2所高校3个不同专业共873名大学生进行问卷调查.结果 与公共卫生专业学生比较,人类学和社会工作专业学生对甲型H1NI流感的传播知识掌握较少(P0.05).结论 公共卫生专业大学生对甲型H1N1流感相关知识了解相对较多,但预防行为尚待提高.

  1. 孕妇对甲型H1N1流感的认知态度调查%Study on the cognitive situation of influenza A(H1N1) among antenatal-checkup pregnant women

    郑冬燕; 曹敏; 王丹凤


    目的:了解在我院进行产检孕妇对甲型H1N1流感的基本认知和态度,为制定有效的防控措施,开展相关的健康教育提供依据.方法:采用自行设计的调查问卷,采用随机抽样的方法,对我院产检的孕妇进行自填式问卷调查.结果:孕妇对甲型H1N1流感相关知识的知晓率为99.64%;文化程度越高的孕妇越能正确面对甲型H1N1流感(P<0.05);孕妇获取甲型H1N1流感相关知识的主要途径为电视、报纸.结论:我院产检孕妇对甲型H1N1流感的知晓率较高;文化程度越高的孕妇,对甲型H1N1流感的知识越关注,越能正确的面对;孕妇获取甲型H1N1流感相关知识的主要途径是媒体宣传.%Objective:To study the cognitive situation and attitude of influenza A( H1N1 ) among pregnant women that Antenatal checkup in our hospital to help making plan for influenza A( H1N1 ) prevention and providing relative health education.Methods: Self - made questionnaire was used for the random sampling investigation of pregnant women that Antenatal checkup in our hospital.Results:99.64% pregnant women had relative knowledge of influenza A ( H1N1 ); Pregnant women with higher education background had better Cognitive Situation of influenza A( H1N1 )( P < 0.05 ); The main approaches of acknowledgment of relative knowledge of influenza A ( H1N1 ) were by TV ( 90.58% )and newspaper ( 62.68% ).Conclusion:Most of pregnant women that Antenatal checkup in our hospital had relative knowledge of influenza A( H1N1 ).Pregnant women with higher education background paid more attention to influenza A( H1N1 ) and had better cognizance of influenza A( H1N1 ).The main approaches of acknowledgment of influenza A( H1N1 ) relative knowledge was by media.

  2. Experimental infection with H1N1 European swine influenza virus protects pigs from an infection with the 2009 pandemic H1N1 human influenza virus

    Busquets, Núria; Segalés, Joaquim; Córdoba, Lorena; Mussá, Tufaria; Crisci, Elisa; Martín-Valls, Gerard E.; Simon-Grifé, Meritxell; Pérez-Simó, Marta; Pérez-Maíllo, Monica; Núñez, Jose I.; Abad, Francesc X.; Fraile, Lorenzo; Pina, Sonia; Majó, Natalia; Bensaid, Albert


    The recent pandemic caused by human influenza virus A(H1N1) 2009 contains ancestral gene segments from North American and Eurasian swine lineages as well as from avian and human influenza lineages. The emergence of this A(H1N1) 2009 poses a potential global threat for human health and the fact that it can infect other species, like pigs, favours a possible encounter with other influenza viruses circulating in swine herds. In Europe, H1N1, H1N2 and H3N2 subtypes of swine influenza virus curren...

  3. Epidemiologic study of influenza A/H1N1 outbreak in a middle school in Haidian District, Beijing%北京市某中学聚集性甲型H1N1流感暴发疫情调查

    韦懿芸; 郭菁; 华伟玉; 孙亚敏; 王江敏; 蔡润; 刘锋


    目的 了解北京市海淀区某中学聚集性甲型H1N1流感暴发的流行特征,为学校甲型H1N1流感疫情的控制提供科学依据.方法 收集该校甲型H1N1患者基本资料和疫情发生学校基本情况,采用描述性流行病学方法对该起疫情进行流行病学分析.结果 甲型H1N1流感暴发疫情历时17 d,累计确诊109名病例,学生罹息率为5.08%(104/2 048),教师罹患率为2.23%(5/224),隐性感染者比例为7.34%(8/109);与2008年同期比较,流感样病例比例差异有统计学意义;疫情初期发病学生以初二年级学生为主,中、后期扩散至初三及其他年级;不同性别人群罹患率差异有统计学意义;病例临床特征典型;甲型H1N1流感病例占流感样病例30.95%(104/336).结论 此次疫情为一起输入性甲型H1N1流感暴发疫情.严格执行校园内的晨午检和疫情报告制度,及时隔离病人及密切接触者,积极开展健康教育和对易感人群的免疫接种,可预防和控制甲型H1N1流感疫情的发生与流行.%Objective To study the epidemiological characters of an influerza A/H1N1 outbreak in a middle school in Haidian district, and to provide effective and scientific measures of respiratory diseases prevention and control in schools. Methods The data of every patient and basic information of school were collected, and epidemiological descriptive analysis was conducted in the study. Results The duration of the influenza A/H1N 1 outbreak was seventeen days. One hundred and nine patients were diagnosed and the attack rate of students was 5.08% ( 104/2 048 ), the attack rate of teachers was 2.23% ( 5/224 ) and the proportion of recessive infected patients was 7.34% ( 8/109 ). The incidence rate of influenza likely patient of 2009 was higher than that of 2008. In the early period, most patients were grade two of junior high school, while in the middle period and the later period, most patients were grade three of junior high school. There

  4. Global Variability in Reported Mortality for Critical Illness during the 2009-10 Influenza A(H1N1) Pandemic: A Systematic Review and Meta-Regression to Guide Reporting of Outcomes during Disease Outbreaks

    Pinto, Ruxandra; Rubenfeld, Gordon; Fowler, Robert A.


    Purpose To determine how patient, healthcare system and study-specific factors influence reported mortality associated with critical illness during the 2009–2010 Influenza A (H1N1) pandemic. Methods Systematic review with meta-regression of studies reporting on mortality associated with critical illness during the 2009–2010 Influenza A (H1N1) pandemic. Data Sources Medline, Embase, LiLACs and African Index Medicus to June 2009-March 2016. Results 226 studies from 50 countries met our inclusion criteria. Mortality associated with H1N1-related critical illness was 31% (95% CI 28–34). Reported mortality was highest in South Asia (61% [95% CI 50–71]) and Sub-Saharan Africa (53% [95% CI 29–75]), in comparison to Western Europe (25% [95% CI 22–30]), North America (25% [95% CI 22–27]) and Australia (15% [95% CI 13–18]) (Peconomic status of the outbreak location. Outcomes from a relatively small number of patients from specific regions may lead to biased estimates of outcomes on a global scale. PMID:27170999

  5. 'Rhyme or reason?' Saying no to mass vaccination: subjective re-interpretation in the context of the A(H1N1) influenza pandemic in Sweden 2009-2010.

    Lundgren, Britta


    During the swine flu pandemic of 2009-2010, all Swedish citizens were recommended to be vaccinated with the influenza vaccine Pandemrix. However, a very serious and unexpected side effect emerged during the summer of 2010: more than 200 children and young adults were diagnosed with narcolepsy after vaccination. Besides the tragic outcome for these children and their families, this adverse side effect suggests future difficulties in obtaining trust in vaccination in cases of emerging pandemics, and thus there is a growing need to find ways to understand the complexities of vaccination decision processes. This article explores written responses to a questionnaire from a Swedish folk life archive as an unconventional source for analysing vaccine decisions. The aim is to investigate how laypersons responded to and re-interpreted the message about the recommended vaccination in their answers. The answers show the confusion and complex circumstances and influences in everyday life that people reflect on when making such important decisions. The issue of confusion is traced back to the initial communications about the vaccination intervention in which both autonomy and solidarity were expected from the population. Common narratives and stories about the media or 'big pharma capitalism' are entangled with private memories, accidental coincidences and serendipitous associations. It is obvious that vaccination interventions that require compliance from large groups of people need to take into account the kind of personal experience narratives that are produced by the complex interplay of the factors described by the informants. PMID:26077985

  6. [Recommendations of the Infectious Diseases Work Group (GTEI) of the Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC) and the Infections in Critically Ill Patients Study Group (GEIPC) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) for the diagnosis and treatment of influenza A/H1N1 in seriously ill adults admitted to the Intensive Care Unit].

    Rodríguez, A; Alvarez-Rocha, L; Sirvent, J M; Zaragoza, R; Nieto, M; Arenzana, A; Luque, P; Socías, L; Martín, M; Navarro, D; Camarena, J; Lorente, L; Trefler, S; Vidaur, L; Solé-Violán, J; Barcenilla, F; Pobo, A; Vallés, J; Ferri, C; Martín-Loeches, I; Díaz, E; López, D; López-Pueyo, M J; Gordo, F; del Nogal, F; Marqués, A; Tormo, S; Fuset, M P; Pérez, F; Bonastre, J; Suberviola, B; Navas, E; León, C


    The diagnosis of influenza A/H1N1 is mainly clinical, particularly during peak or seasonal flu outbreaks. A diagnostic test should be performed in all patients with fever and flu symptoms that require hospitalization. The respiratory sample (nasal or pharyngeal exudate or deeper sample in intubated patients) should be obtained as soon as possible, with the immediate start of empirical antiviral treatment. Molecular methods based on nucleic acid amplification techniques (RT-PCR) are the gold standard for the diagnosis of influenza A/H1N1. Immunochromatographic methods have low sensitivity; a negative result therefore does not rule out active infection. Classical culture is slow and has low sensitivity. Direct immunofluorescence offers a sensitivity of 90%, but requires a sample of high quality. Indirect methods for detecting antibodies are only of epidemiological interest. Patients with A/H1N1 flu may have relative leukopenia and elevated serum levels of LDH, CPK and CRP, but none of these variables are independently associated to the prognosis. However, plasma LDH> 1500 IU/L, and the presence of thrombocytopenia high suspicion of influenza A/H1N1 infection must continue with antiviral treatment, regardless of the negative results of initial tests, unless an alternative diagnosis can be established or clinical criteria suggest a low probability of influenza. In patients with influenza A/H1N1 pneumonia, empirical antibiotic therapy should be provided due to the possibility of bacterial coinfection. A beta-lactam plus a macrolide should be administered as soon as possible. The microbiological findings and clinical or laboratory test variables may decide withdrawal or not of antibiotic treatment. Pneumococcal vaccination is recommended as a preventive measure in the population at risk of suffering severe complications. Although the use of moderate- or low-dose corticosteroids has been proposed for the treatment of influenza A/H1N1 pneumonia, the existing scientific

  7. Influenza Virus Resistance to Antiviral Agents: A Plea for Rational Use

    Poland, Gregory A.; Jacobson, Robert M.; Ovsyannikova, Inna G.


    Although influenza vaccine can prevent influenza virus infection, the only therapeutic options to treat influenza virus infection are antiviral agents. At the current time, nearly all influenza A/H3N2 viruses and a percentage of influenza A/H1N1 viruses are adamantane resistant, which leaves only neuraminidase inhibitors available for treatment of infection with these viruses. In December 2008, the Centers for Disease Control and Prevention released new data demonstrating that a high percenta...

  8. Swine Influenza in Sri Lanka

    Perera, Harsha K. K.; Wickramasinghe, Geethani; Cheung, Chung L; Nishiura, Hiroshi; Smith, David K.; Poon, Leo L M; Perera, Aluthgama K. C.; Ma, Siu K; Sunil-Chandra, Narapiti P.; Guan, Yi; Peiris, Joseph S. M.


    To study influenza viruses in pigs in Sri Lanka,we examined samples from pigs at slaughterhouses. Influenza (H3N2) and A(H1N1)pdm09 viruses were prevalent during 2004–2005 and 2009–2012, respectively. Genetic and epidemiologic analyses of human and swine influenza viruses indicated 2 events of A(H1N1)pdm09 virus spillover from humans to pigs.

  9. Viral Etiology of Chronic Obstructive Pulmonary Disease Exacerbations during the A/H1N1pdm09 Pandemic and Postpandemic Period

    Ivan Sanz


    Full Text Available Viral infections are one of the main causes of acute exacerbations of chronic obstructive pulmonary disease (AE-COPD. Emergence of A/H1N1pdm influenza virus in the 2009 pandemic changed the viral etiology of exacerbations that were reported before the pandemic. The aim of this study was to describe the etiology of respiratory viruses in 195 Spanish patients affected by AE-COPD from the pandemic until the 2011-12 influenza epidemic. During the study period (2009–2012, respiratory viruses were identified in 48.7% of samples, and the proportion of viral detections in AE-COPD was higher in patients aged 30–64 years than ≥65 years. Influenza A viruses were the pathogens most often detected during the pandemic and the following two influenza epidemics in contradistinction to human rhino/enteroviruses that were the main viruses causing AE-COPD before the pandemic. The probability of influenza virus detection was 2.78-fold higher in patients who are 30–64 years old than those ≥65. Most respiratory samples were obtained during the pandemic, but the influenza detection rate was higher during the 2011-12 epidemic. There is a need for more accurate AE-COPD diagnosis, emphasizing the role of respiratory viruses. Furthermore, diagnosis requires increased attention to patient age and the characteristics of each influenza epidemic.

  10. Molecular Epidemiology and Evolution of Influenza Viruses Circulating within European Swine between 2009 and 2013

    J. Watson, Simon; Langat, Pinky; M. Reid, Scott;


    The emergence in humans of the A(H1N1)pdm09 influenza virus, a complex reassortant virus of swine origin, highlighted the importance of worldwide influenza virus surveillance in swine. To date, large-scale surveillance studies have been reported for southern China and North America, but such data...

  11. Swine-origin influenza-virus-induced acute lung injury:Novel or classical pathogenesis?

    Naoyoshi; Maeda; Toshimitsu; Uede


    Influenza viruses are common respiratory pathogens in humans and can cause serious infection that leads to the development of pneumonia.Due to their hostrange diversity,genetic and antigenic diversity,and potential to reassort genetically in vivo,influenza A viruses are continual sources of novel influenza strains that lead to the emergence of periodic epidemics and outbreaks in humans.Thus,newly emerging viral diseases are always major threats to public health.In March 2009,a novel influenza virus suddenly emerged and caused a worldwide pandemic.The novel pandemic influenza virus was genetically and antigenically distinct from previous seasonal human influenza A/H1N1 viruses;it was identified to have originated from pigs,and further genetic analysis revealed it as a subtype of A/H1N1,thus later called a swine-origin influenza virus A/H1N1.Since the novel virus emerged,epidemiological surveys and research on experimental animal models have been conducted,and characteristics of the novel influenza virus have been determined but the exact mechanisms of pulmonary pathogenesis remain to be elucidated.In this editorial,we summa-rize and discuss the recent pandemic caused by the novel swine-origin influenza virus A/H1N1 with a focus on the mechanism of pathogenesis to obtain an insight into potential therapeutic strategies.

  12. Pandemic H1N1 influenza virus infection in a Canadian cat.

    Knight, Cameron G; Davies, Jennifer L; Joseph, Tomy; Ondrich, Sarah; Rosa, Brielle V


    A cat was presented for necropsy after being found dead at home. Histologic findings suggested viral pneumonia. Polymerase chain reaction and viral typing revealed influenza A(H1N1)pdm09. This is the first report of influenza in a Canadian cat and highlights the importance of considering influenza virus in the differential diagnosis for feline respiratory distress. PMID:27152036

  13. Interaction of nanodiamonds materials with influenza viruses

    The perspectives of the application of modern materials contained nanodiamonds (ND) are considered in this study. The interaction between detonation paniculate ND, soot and influenza A and B viruses, fragments of cDNA were analyzed at the normal conditions. It was shown that these sorbents can interact with the following viruses: reference epidemic strains of influenza A(H1N1), A(H1N1)v, A(H3N2) and B viruses circulated in the word in 2000-2010. The allantoises, concentrated viruses, cDNA can be absorbed by ND sorbents and getting removed from water solutions within 20 min. ND sorbents can be used for the preparation of antivirus filters for water solution and for future diagnostic systems in virology.

  14. Prospective hospital-based case–control study to assess the effectiveness of pandemic influenza A(H1N1pdm09 vaccination and risk factors for hospitalization in 2009–2010 using matched hospital and test-negative controls

    Hellenbrand Wiebke


    Full Text Available Abstract Background We performed a case–control study to estimate vaccine effectiveness (VE for prevention of hospitalization due to pandemic influenza A(H1N1pdm09 (pH1N1 and to identify risk factors for pH1N1 and acute respiratory infection (ARI in 10 hospitals in Berlin from December 2009 to April 2010. Methods Cases were patients aged 18–65 years with onset of ARI ≤10 days before admission testing positive for pH1N1 by PCR performed on nasal and throat swabs or by serological testing. Cases were compared to (1 matched hospital controls with acute surgical, traumatological or other diagnoses matched on age, sex and vaccination probability, and (2 ARI patients testing negative for pH1N1. Additionally, ARI cases were compared to matched hospital controls. A standardized interview and chart review elicited demographic and clinical data as well as potential risk factors for pH1N1/ARI. VE was estimated by 1-(Odds ratio for pH1N1-vaccination ≥10 days before symptom onset using exact logistic regression analysis. Results Of 177 ARI cases recruited, 27 tested pH1N1 positive. A monovalent AS03-adjuvanted pH1N1 vaccine was the only pandemic vaccine type identified among cases and controls (vaccination coverage in control group 1 and 2: 15% and 5.9%. The only breakthrough infections were observed in 2 of 3 vaccinated HIV positive pH1N1 patients. After exclusion of HIV positive participants, VE was 96% (95%CI: 26-100% in the matched multivariate analysis and 46% (95%CI: -376-100% in the test-negative analysis. Exposure to children in the household was independently associated with hospitalization for pH1N1 and ARI. Conclusions Though limited by low vaccination coverage and number of pH1N1 cases, our results suggest a protective effect of the AS03-adjuvanted pH1N1 vaccine for the prevention of pH1N1 hospitalization. The use of hospital but not test-negative controls showed a statistically protective effect of pH1N1-vaccination and permitted

  15. Global circulation patterns of seasonal influenza viruses vary with antigenic drift

    Bedford, Trevor; Riley, Steven; Barr, Ian G.; Broor, Shobha; Chadha, Mandeep; Cox, Nancy J.; Daniels, Rodney S.; Gunasekaran, C. Palani; Hurt, Aeron C.; Kelso, Anne; Klimov, Alexander; Lewis, Nicola S.; Li, Xiyan; McCauley, John W.; Odagiri, Takato; Potdar, Varsha; Rambaut, Andrew; Shu, Yuelong; Skepner, Eugene; Smith, Derek J.; Suchard, Marc A.; Tashiro, Masato; Wang, Dayan; Xu, Xiyan; Lemey, Philippe; Russell, Colin A.


    Understanding the spatiotemporal patterns of emergence and circulation of new human seasonal influenza virus variants is a key scientific and public health challenge. The global circulation patterns of influenza A/H3N2 viruses are well characterized, but the patterns of A/H1N1 and B viruses have remained largely unexplored. Here we show that the global circulation patterns of A/H1N1 (up to 2009), B/Victoria, and B/Yamagata viruses differ substantially from those of A/H3N2 viruses, on the basis of analyses of 9,604 haemagglutinin sequences of human seasonal influenza viruses from 2000 to 2012. Whereas genetic variants of A/H3N2 viruses did not persist locally between epidemics and were reseeded from East and Southeast Asia, genetic variants of A/H1N1 and B viruses persisted across several seasons and exhibited complex global dynamics with East and Southeast Asia playing a limited role in disseminating new variants. The less frequent global movement of influenza A/H1N1 and B viruses coincided with slower rates of antigenic evolution, lower ages of infection, and smaller, less frequent epidemics compared to A/H3N2 viruses. Detailed epidemic models support differences in age of infection, combined with the less frequent travel of children, as probable drivers of the differences in the patterns of global circulation, suggesting a complex interaction between virus evolution, epidemiology, and human behaviour.

  16. Immunity to seasonal and pandemic influenza A viruses

    Valkenburg, Sophie A.; Rutigliano, John A.; Ellebedy, Ali H.; Doherty, Peter C.; THOMAS, PAUL G.; Kedzierska, Katherine


    The introduction of a new influenza strain into human circulation leads to rapid global spread. This review summarizes innate and adaptive immunity to influenza viruses, with an emphasis on T-cell responses that provide cross-protection between distinct subtypes and strains. We discuss antigenic variation within T-cell immunogenic peptides and our understanding of pre-existing immunity towards the pandemic A(H1N1) 2009 strain.

  17. Pneumonia por Influenza A(H1N1 em paciente imunossuprimido após transplante cardíaco Neumonía por Influenza A (H1N1 en paciente inmunosuprimido tras transplante cardiaco Influenza A (H1N1 pneumonia in an immunossupressed patient after heart transplantation

    Fernando Bacal


    Full Text Available O papel da resposta imunológica durante a infecção pelo vírus Influenza H1N1 não está totalmente estabelecido, mas acredita-se que atue de forma decisiva no agravamento do quadro e no aparecimento da síndrome de desconforto respiratório agudo. O papel de terapias imunomoduladoras no controle de infecções virais também não é consensual e faltam dados de literatura para se definir as indicações de seu uso. Neste relato de caso, apresentamos, segundo nosso conhecimento, pela primeira vez, o relato de um paciente transplantado cardíaco que apresentou infecção pelo vírus H1N1 e evoluiu de forma favorável, trazendo um questionamento sobre o real papel da terapia imunossupressora como fator de risco para a forma grave da doença.El rol de la respuesta inmunológica durante la infección por el virus Influenza H1N1 no está totalmente establecido, sino que se cree que él actúe de forma decisiva en el agravamiento del cuadro y en el surgimiento del síndrome de distrés respiratorio agudo. El papel de terapias inmunomoduladoras en el control de infecciones virales también no es consensual y nos faltan datos de la literatura para definirse las indicaciones de su utilización. En este caso clínico presentamos, según nuestro conocimiento, por primera vez, el relato de un paciente transplantado cardiaco que presentó infección por el virus H1N1 y evolucionó de forma favorable, y aprovechamos para poner en cuestión el real papel de la terapia inmunosupresora como factor de riesgo para la forma severa de la enfermedad.The role of the immune response during Influenza H1N1 virus infection is not yet fully established, but it is believed that it decisively participates in the severity of the disease as well as in the development of acute respiratory distress syndrome. The role of immunomodulating therapies in the control of viral infections is not a consensus either, and data from the literature defining the indications for their use

  18. Virus susceptibility and clinical effectiveness of anti-influenza drugs during the 2010–2011 influenza season in Russia

    I.A. Leneva; E.I. Burtseva; S.B. Yatsyshina; I.T. Fedyakina; E.S. Kirillova; E.P. Selkova; Osipova, E.; V. V. Maleev


    Background: Antiviral drugs are critical adjuncts to influenza vaccination. This study determined the in vitro susceptibilities of influenza A and B viruses isolated in the 2010–2011 season in Russia to the neuraminidase inhibitor oseltamivir and the hemagglutinin fusion inhibitor umifenovir and clinical efficacy of this antiviral drugs in this season. Methods: The antiviral potency of these drugs against A(H1N1)pdm09 virus in mice was assessed. Importantly, the clinical effectiveness of o...

  19. Bioactive Compounds Screening from Zingiberaceae Family as Influenza A/Swine Flu Virus Neuraminidase Inhibitor through Docking Approach

    Tambunan, Usman S. F.; Fadilah; Parikesit, Arli A.


    Problem statement: Influenza A/H1N1 is a disease caused by infection of influenza a virus subtype H1N1. It is a major health problem in tropical and subtropical countries. This virus constantly mutates and consequently will be developed into new drug-resistant strains. Approach: In this research, we have conducted docking study to screen bioactive compounds from Zingiberaceae family, which has a role as neuraminidase inhibitor of influenza a virus. Results: The docking res...

  20. Antiviral drug profile of human influenza A & B viruses circulating in India: 2004-2011

    V A Potdar


    Full Text Available Background & objectives: Recent influenza antiviral resistance studies in South East Asia, Europe and the United States reveal adamantane and neuraminidase inhibitor (NAIs resistance. This study was undertaken to evaluate antiviral resistance in influenza viruses isolated from various parts of India, during 2004 to 2011. Methods: Influenza viruses were analyzed genetically for known resistance markers by M2 and NA gene sequencing. Influenza A/H1N1 (n=206, A/H3N2 (n=371 viruses for amantadine resistance and A/H1N1 (n=206, A/H3N2 (n=272 and type B (n=326 for oseltamivir resistance were sequenced. Pandemic (H1N1 (n= 493 isolates were tested for H274Y mutation by real time reverse transcription (rRT-PCR. Randomly selected resistant and sensitive influenza A/H1N1 and A/H3N2 viruses were confirmed by phenotypic assay. Results: Serine to asparagine (S3IN mutation was detected in six isolates of 2007-2008.One dual-resistant A/H1N1 was detected for the first time in India with leucine to phenylalanine (L26F mutation in M2 gene and H274Y mutation in NA gene. A/H3N2 viruses showed an increase in resistance to amantadine from 22.5 per cent in 2005 to 100 per cent in 2008 onwards with S3IN mutation. Fifty of the 61 (82% A/H1N1 viruses tested in 2008-2009 were oseltamivir resistant with H274Y mutation, while all A/H3N2, pandemic A/H1N1 and type B isolates remained sensitive. Genetic results were also confirmed by phenotypic analysis of randomly selected 50 resistant A/H1N1 and 40 sensitive A/H3N2 isolates. Interpretation & conclusions: Emergence of influenza viruses resistant to amantadine and oseltamivir in spite of negligible usage of antivirals emphasizes the need for continuous monitoring of antiviral resistance.

  1. Nationwide molecular surveillance of pandemic H1N1 influenza A virus genomes: Canada, 2009.

    Morag Graham

    Full Text Available BACKGROUND: In April 2009, a novel triple-reassortant swine influenza A H1N1 virus ("A/H1N1pdm"; also known as SOIV was detected and spread globally as the first influenza pandemic of the 21(st century. Sequencing has since been conducted at an unprecedented rate globally in order to monitor the diversification of this emergent virus and to track mutations that may affect virus behavior. METHODOLOGY/PRINCIPAL FINDINGS: By Sanger sequencing, we determined consensus whole-genome sequences for A/H1N1pdm viruses sampled nationwide in Canada over 33 weeks during the 2009 first and second pandemic waves. A total of 235 virus genomes sampled from unique subjects were analyzed, providing insight into the temporal and spatial trajectory of A/H1N1pdm lineages within Canada. Three clades (2, 3, and 7 were identifiable within the first two weeks of A/H1N1pdm appearance, with clades 5 and 6 appearing thereafter; further diversification was not apparent. Only two viral sites displayed evidence of adaptive evolution, located in hemagglutinin (HA corresponding to D222 in the HA receptor-binding site, and to E374 at HA2-subunit position 47. Among the Canadian sampled viruses, we observed notable genetic diversity (1.47 x 10⁻³ amino acid substitutions per site in the gene encoding PB1, particularly within the viral genomic RNA (vRNA-binding domain (residues 493-757. This genome data set supports the conclusion that A/H1N1pdm is evolving but not excessively relative to other H1N1 influenza A viruses. Entropy analysis was used to investigate whether any mutated A/H1N1pdm protein residues were associated with infection severity; however no virus genotypes were observed to trend with infection severity. One virus that harboured heterozygote coding mutations, including PB2 D567D/G, was attributed to a severe and potentially mixed infection; yet the functional significance of this PB2 mutation remains unknown. CONCLUSIONS/SIGNIFICANCE: These findings contribute to

  2. Oseltamivir resistance among influenza viruses: surveillance in northern Viet Nam, 2009–2012

    Nguyen Thi Kim Phuong


    Full Text Available Introduction: Antiviral resistance has been reported in seasonal influenza A viruses and avian influenza A(H5N1 viruses in Viet Nam, raising concerns about the efficacy of treatment. Methods: We analysed specimens from two sources during the period 2009–2012: influenza-positive samples from influenza-like illness patients at sentinel clinics in northern Viet Nam and isolates from patients with confirmed A(H5N1 infections. Pyrosequencing was used to detect mutations: H275Y [for A(H1N1 and A(H5N1], E119V [for A(H3N2] and I117V [for A(H5N1]. A neuraminidase inhibition assay was used to determine the Inhibitory Concentration 50 (IC50 values for all influenza A and B isolates. Results: There were 341 influenza A positive samples identified; influenza A(H1N1pdm09 was identified most frequently (n = 215. In 2009, oseltamivir resistance was observed in 100% (19 of 19 of seasonal A(H1N1 isolates and 1.4% (3/215 of A(H1N1pdm09 isolates. This H275Y mutation was not found in influenza subtypes A(H5N1 or A(H3N2 isolates. Discussion: In Viet Nam, seasonal and A(H5N1 influenza vaccines are not currently available; thus, effective treatment is required. The presence of oseltamivir-resistant viruses is therefore a concern. Active surveillance for oseltamivir resistance among influenza viruses circulating in Viet Nam should be continued.

  3. Virological Surveillance of Influenza Viruses during the 2008-09, 2009-10 and 2010-11 Seasons in Tunisia.

    Awatef El Moussi

    Full Text Available BACKGROUND: The data contribute to a better understanding of the circulation of influenza viruses especially in North-Africa. OBJECTIVE: The objective of this surveillance was to detect severe influenza cases, identify their epidemiological and virological characteristics and assess their impact on the healthcare system. METHOD: We describe in this report the findings of laboratory-based surveillance of human cases of influenza virus and other respiratory viruses' infection during three seasons in Tunisia. RESULTS: The 2008-09 winter influenza season is underway in Tunisia, with co-circulation of influenza A/H3N2 (56.25%, influenza A(H1N1 (32.5%, and a few sporadic influenza B viruses (11.25%. In 2010-11 season the circulating strains are predominantly the 2009 pandemic influenza A(H1N1pdm09 (70% and influenza B viruses (22%. And sporadic viruses were sub-typed as A/H3N2 and unsubtyped influenza A, 5% and 3%, respectively. Unlike other countries, highest prevalence of influenza B virus Yamagata-like lineage has been reported in Tunisia (76% localised into the clade B/Bangladesh/3333/2007. In the pandemic year, influenza A(H1N1pdm09 predominated over other influenza viruses (95%. Amino acid changes D222G and D222E were detected in the HA gene of A(H1N1pdm09 virus in two severe cases, one fatal case and one mild case out of 50 influenza A(H1N1pdm09 viruses studied. The most frequently reported respiratory virus other than influenza in three seasons was RSV (45.29%. CONCLUSION: This article summarises the surveillance and epidemiology of influenza viruses and other respiratory viruses, showing how rapid improvements in influenza surveillance were feasible by connecting the existing structure in the health care system for patient records to electronic surveillance system for reporting ILI cases.

  4. Multiple reassortment events in the evolutionary history of H1N1 influenza A virus since 1918.

    Martha I Nelson


    Full Text Available The H1N1 subtype of influenza A virus has caused substantial morbidity and mortality in humans, first documented in the global pandemic of 1918 and continuing to the present day. Despite this disease burden, the evolutionary history of the A/H1N1 virus is not well understood, particularly whether there is a virological basis for several notable epidemics of unusual severity in the 1940s and 1950s. Using a data set of 71 representative complete genome sequences sampled between 1918 and 2006, we show that segmental reassortment has played an important role in the genomic evolution of A/H1N1 since 1918. Specifically, we demonstrate that an A/H1N1 isolate from the 1947 epidemic acquired novel PB2 and HA genes through intra-subtype reassortment, which may explain the abrupt antigenic evolution of this virus. Similarly, the 1951 influenza epidemic may also have been associated with reassortant A/H1N1 viruses. Intra-subtype reassortment therefore appears to be a more important process in the evolution and epidemiology of H1N1 influenza A virus than previously realized.

  5. Virological analysis of fatal influenza cases in the United Kingdom during the early wave of influenza in winter 2010/11.

    Ellis, J; Galiano, M; Pebody, R; Lackenby, A; Thompson, C; Bermingham, A; McLean, E; Zhao, H; Bolotin, S; Dar, O; Watson, J M; Zambon, M


    The 2010/11 winter influenza season is underway in the United Kingdom, with co-circulation of influenza A(H1N1)2009 (antigenically similar to the current 2010/11 vaccine strain), influenza B (mainly B/Victoria/2/87 lineage, similar to the 2010/11 vaccine strain) and a few sporadic influenza A(H3N2) viruses. Clinical influenza activity has been increasing. Severe illness, resulting in hospitalisation and deaths, has occurred in children and young adults and has predominantly been associated with influenza A(H1N1)2009, but also influenza B viruses. PMID:21223836

  6. Construction of the influenza A virus transmission tree in a college-based population: co-transmission and interactions between influenza A viruses

    Zhang, Xu-Sheng; De Angelis, Daniela


    Background Co-infection of different influenza A viruses is known to occur but how viruses interact within co-infection remains unknown. An outbreak in a college campus during the 2009 pandemic involved two subtypes of influenza A: persons infected with pandemic A/H1N1; persons infected with seasonal A/H3N2 viruses; and persons infected with both at the same time (co-infection). This provides data to analyse the possible interaction between influenza A viruses within co-infection. Methods We ...

  7. 上海地区甲型H1N1流行性感冒流行病学调查和临床特征分析%Epidemiological survey and clinical analysis of patients with influenza A(H1N1)in Shanghai

    欧强; 殷科珊; 陆云飞; 黄琴; 张志勇; 卢洪洲


    目的 了解上海地区新型甲型H1N1流行性感冒(流感)的流行病学和临床特征,提高临床医师对本病的认识.方法 采用描述性流行病学方法对上海市公共卫生临床中心2009年5月23日至6月30日收治确诊的100例甲型H1N1流感患者资料进行回顾性分析.结果 本组患者男58例,女42例,年龄4~75岁.96例为输入性病例,主要来自澳大利亚、美国、加拿大.临床主要表现为流感样症状,包括发热、咳嗽、咽痛,其他症状有咳痰、流涕、咽痒、鼻塞、头痛和全身酸痛等,体征有咽部充血、扁桃体肿大等.外周血WBC总数正常或偏低.部分患者CD4+T淋巴细胞低于正常下限水平.胸部CT检查主要表现为肺纹理增粗、肺炎、胸膜增厚、胸膜炎.治疗首选奥司他韦,不良反应少见,多数患者可以耐受.本病预后良好,所有患者治愈出院.结论 新型甲型H1N1流感传染性强,并可影响机体细胞免疫功能,但症状轻微,早期采用奥司他韦抗病毒治疗,疗效满意.疾病防控部门应加强监测,积极应对本次甲型H1N1流感大流行.%Objective To understand the epidemiological and clinical characteristics of A virus subtype H1N1 influenza in Shanghai and improve the recognition of the disease in physicians.Methods The epidemiological information and clinical characteristics of 100 patients with A virus subtype H1N1 influenza hospitalized in Shanghai Public Health Clinical Center from May 23 to Jan 30 in 2009 were analysised retrospectively by descriptive epidemiology.Results There were 58 males and 42 females in this group.The range of age was from 4 years to 75 years.Ninety-six patients were imported cases and most cases came from Australia,the United States and Canada.The main symptoms were influenza-like symptoms including fever,cough and sore throat.Other symptoms included expectoration,nasal discharge,throat itching,nasal obstruction,headache,muscular pain and so on.Physical signs

  8. Analysis of diagnostic and handling procedures of the first imported case of A/H1N1 influenza in mainland China%中国内地首例输入性甲型H1N1流感病例诊断处置流程分析

    胡卫建; 吴佳玉; 王晓梅


    .5% ;the chest X-ray shewed that texture increased and the heart shadow augmented on both lungs; the result of throat swab culture was negative. The result of virus nucleic aeid detected by Sichnan Provincial Center for Disease Control showed H1N1 influenza virus, suspected. Sichuan Province Health organization organized experts on the prevention and control of H1N1 influenza for consultation, and the patient was diagnosed as the first suspected H1N1 influenza case in mainland China based on the epidemiological investigation, symptoms and signs of the patient, the results of laboratory ex-amination, and the result of virus test. Confirmed by the experts from Chinese center for disease control and pre-vention and The Ministry of Health of the People's Republic of China, the patient was diagnosed as the first H1N1 influenza case in mainland China.

  9. 甲型H1N1流感病毒非结构蛋白NS1真核表达载体的构建与表达%Construction and expression of eukaryotic expression vector of NS1 protein of influenza A(H1N1)

    张文帅; 卞倩; 温恬; 迟莹; 李燕; 焦永军


    目的:构建甲型H1N1流感病毒非结构蛋白NS1真核表达载体并表达其编码蛋白(转染293T细胞).方法:从江苏首例甲型H1NI流感病毒毒株(A/Nanjing/1/2009(H1N1))提取病毒RNA, 采用RT-PCR技术扩增NS1全长基因, 将其克隆至pMD18-T Vector中构建pMD18-T-NS1质粒, 双酶切pMD18-T-NS1与PXJ40-HA后, 构建真核表达载体PXJ40-HA-NS1,经酶切及测序鉴定后将质粒转染到293T细胞中, 通过Western blot鉴定NS1蛋白的表达.结果:经双酶切、测序鉴定证实NS1基因的真核表达载体构建成功.Western blot法可见NS1基因编码蛋白的成功表达.结论:成功克隆NS1全长基因, 并构建了其真核表达载体, 该表达载体的构建为后期建立稳定表达NS1蛋白的细胞模型和NS1蛋白功能研究提供了材料.%AIM: To insert the full-length NS1 gene of influenza A (H1N1) into an eukaryotic expression vector PXJ40-HA, and to evaluate the expression of NS1 gene in transfected 293T cells. METHODS: The NS1 gene of influenza A ( H1 N1 ) was amplified by RT-PCR and cloned into pMD18-T vector to construct a plasmid, named pMD18-TNS1. The pMD18-T-NS1 and the PXJ40-HA were both digested using the same restrict enzymes and ligated, yielding the recombinant eukaryotic expression vector PXJ40-HANS1. The expression of the NS1 gene in transfected 293T ceils wes tested by Western blot. RESULTS: The recombinant eukaryotic expression vector PXJ40-HA-NS1 was successfully constructed. The NS1 protein was observed to be expressed in 293T cells. CONCLUSION: The full-length NSl gene is obtained and its recombinant eukaryotic expression plesmid is successfully constructed. This study is of help to further understanding the biological function of NSl protein and the mechanism of diseases induced by influenza A virus.

  10. Cats as a potential source of emerging influenza virus infections

    Taisuke; Horimoto; Fumihiro; Gen; Shin; Murakami; Kiyoko; Iwatsuki-Horimoto; Kentaro; Kato; Masaharu; Hisasue; Masahiro; Sakaguchi; Chairul; A.; Nidom; Yoshihiro; Kawaoka


    <正>Dear Editor,Historically,the influenza virus has not been regarded as a major pathogen of cats.However,since 2003,natural infections of domestic cats with highly pathogenic H5N1 avian virus causing fatal cases have been reported(Songserm et al.,2006;Yingst et al.,2006;Klopfleisch et al.,2007).Furthermore,infections of this animal with A(H1N1)pdm09 virus,causing respiratory illness with some fatal cases,have also been reported in various parts

  11. Severity of pneumonia due to new H1N1 influenza virus in ferrets is intermediate between that due to seasonal H1N1 virus and highly pathogenic avian influenza H5N1 virus

    Brand, Judith; Stittelaar, Koert; Amerongen, Geert van; Rimmelzwaan, Guus; Simon, James; de Wit, Emmie; Munster, Vincent; Bestebroer, Theo; Fouchier, Ron; Kuiken, Thijs; Osterhaus, Ab


    textabstractBackground. The newly emerged influenza A(H1N1) virus (new H1N1 virus) is causing the first influenza pandemic of this century. Three influenza pandemics of the previous century caused variable mortality, which largely depended on the development of severe pneumonia. However, the ability of the new H1N1 virus to cause pneumonia is poorly understood. Methods. The new H1N1 virus was inoculated intratracheally into ferrets. Its ability to cause pneumonia was compared with that of sea...

  12. Influenza virus surveillance in Argentina during the 2012 season: antigenic characterization, genetic analysis and antiviral susceptibility.

    Benedetti, E; Daniels, R S; Pontoriero, A; Russo, M; Avaro, M; Czech, A; Campos, A; Periolo, N; Gregory, V; McCauley, J W; Baumeister, E G


    The activity and circulation of influenza viruses in Argentina was studied during 2012 as part of the Argentinean Surveillance for Influenza and other Respiratory Viruses, in the context of Global Influenza Surveillance. The antigenicity and molecular characteristics of haemagglutinins (HA) of circulating influenza A and B viruses were analysed to assess the emergence of virus variants. Susceptibility to oseltamivir and zanamivir was evaluated by enzymatic assay and results were backed-up by sequencing of the neuraminidase (NA) genes. During the 2012 season, influenza virus circulation in Argentina was detected from weeks 24 to 51. The HA sequences of the studied A(H1N1)pdm09 subtype viruses segregated in a different genetic group compared to those identified during the 2009 pandemic, although they were still closely related antigenically to the vaccine virus A/California/07/2009. The HA sequences of the A(H3N2) viruses analysed fell into the A/Victoria/208/2009 clade, genetic group 3C. A mixed circulation of virus variants belonging to B/Victoria and B/Yamagata lineages was detected, with B/Victoria being dominant. All viruses tested were sensitive to oseltamivir and zanamivir except one. This isolate, an A(H1N1)pdm09 virus possessing the substitution NA-N295S, showed highly reduced inhibition by oseltamivir and reduced inhibition by zanamivir. Virological and epidemiological surveillance remains critical for detection of evolving influenza viruses. PMID:26345289

  13. Predicting the Mutating Distribution at Antigenic Sites of the Influenza Virus

    Hongyang Xu; Yiyan Yang; Shuning Wang; Ruixin Zhu; Tianyi Qiu; Jingxuan Qiu; Qingchen Zhang; Li Jin; Yungang He; Kailin Tang; Zhiwei Cao


    Mutations of the influenza virus lead to antigenic changes that cause recurrent epidemics and vaccine resistance. Preventive measures would benefit greatly from the ability to predict the potential distribution of new antigenic sites in future strains. By leveraging the extensive historical records of HA sequences for 90 years, we designed a computational model to simulate the dynamic evolution of antigenic sites in A/H1N1. With templates of antigenic sequences, the model can effectively pred...

  14. Epidemiology of influenza viruses from 2009-2013-A sentinel surveillance report from Union territory of Puducherry, India

    Ganesh; Nandhini; Sistla; Sujatha


    Objective: To report the i ndings of inl uenza surveillance programme from Union territory of Puducherry and to document the clinical and epidemiological data of inl uenza viruses over a i ve year period from 2009-2013. Methods: Respiratory samples were collected from patients with influenza-like illness from 2009-2013 as part of routine diagnostic and surveillance activity. Detection of pandemic inl uenza A(H1N1) 2009, inl uenza A(H3N2) and inl uenza B was done using Real-time PCR. Results: Of the total 2 247 samples collected from patients with inl uenza-like illness during the study period 287(12.7%) and 92(4.0%) were positive for inl uenza A(H1N1) 2009 and inl uenza A(H3N2) respectively. A subset of 557 of these samples were also tested for inl uenza B and 24(4.3%) were positive. Signii cantly higher positivity rate for both viruses was observed in adults when compared with children. The peak positivity of influenza A(H1N1) 2009 was observed in 2009 followed by 2012, while that of inl uenza A(H3N2) was more uniformly distributed with the exception of 2012. Overall mortality rate due to influenza A(H1N1) 2009 was 7.6% while it was 1% for influenza A(H3N2). Each year influenza-like illness and influenza virus activity coincided with period of high rainfall and low temperature except in the first half of 2012. Conclusions: As the sole referral laboratory in this region, the data provides a comprehensive picture of inl uenza activity. This information will be useful in future planning of the vaccine schedule and inl uenza pandemic preparedness.


    李琳; 徐文体; 董晓春; 张颖; 谢娟


    [目的]了解学生家长对甲型 H1N1 流感暴发后关闭学校这一措施的认可度.[方法]采用统一的问卷对发生甲流暴发疫情的某国际学校 460 名家长进行调查.[结果]回收有效问卷368份,问卷有效率为80%.53.80%家长赞成关闭学校,理由主要是认为关闭学校能保护其他健康学生避免感染(52.53%);46.20%家长反对关闭学校,理由主要是认为仅需膈离病例就能阻止疫情(31.76%).非病例学生家长赞成关闭学校的比例明显高于病例组家长(X2=6.88,P=0·009).年级与赞成关闭学校的比例之间呈负相关,随着年级增高,非病例学生家长赞成关闭学校的比例随之降低(rs=-0.595,P=0.032).[结论]家长对关闭学校的措施存在分歧.提示卫生和教育部分应采取措施,加强健康教育并保障防控措施落实,防止疫情向社区的扩散.%[Objective] To explore the household responses to school closure resulting from influenza A (H1N1) out break. [Methods] We surveyed 460 families affected by pandemic (H1N1) related school closures with uniform questionnaire. [Results] Valid questionnaires were returned for 368 (80%). Closure was considered appropriate by 53.8% of the parents, and the main reason was to protect the healthy students (52.53%); 46.20% of the parents who thought the school closures were not appropriate, and the main reason was enough case-quarantined (31.76%). The percentage of parents who indicated the closure was appropriate was higher among the parents of non-case than the parents of cases (x2 = 6.88, P = 0.009). Parental opinion about the appropriateness of the school closure was negatively correlated with grades (rs =-0.622, P= 0.031). [Con Clusion] Parental opinion on the school closure is different. It is indicated that the departments of health and education should take measures to assure the control measures implemented.

  16. Detection of influenza A virus homo- and heterosubtype-specific memory B-cells using a novel protein microarray-based analysis tool.

    Baas, Dominique C; Koopmans, Marion P; de Bruin, Erwin; ten Hulscher, Hinke I; Buisman, Anne M; Hendrikx, Lotte H; van Beek, Janko; Godeke, Gert-Jan; Reimerink, Johan; van Binnendijk, Robert S


    The emergence of the A(H1N1) 2009 pandemic influenza virus was initially seen as a major world-wide health concern since a low degree of immunity to this virus strain was anticipated. However, age-specific infection attack rates and age-specific differences in seroresponse indicate that pre-existing immunity may have played a significant role in protection especially in older age groups. This study describes the use of a protein microarray as a multiplex analysis tool for detection of influenza virus H1 strain-specific memory B-cells before and after infection with A(H1N1)pdm09. The discrimination was based on detection of specific antibodies in culture supernatants from polyclonally stimulated B-cells against recombinant influenza virus HA1 proteins representing influenza virus subtypes H1 through H9. The protein microarray proved sensitive and specific for antibody detection in culture supernatants of B-cells, and with the potential to deduce a person's history of infection with particular influenza virus variants, including A(H1N1)pdm09. Blood samples obtained from different age groups prior to the pandemic in 2009 partly showed the presence of B-cells producing antibodies binding to the closely related A(H1N1) 1918 pandemic influenza virus, and of which the magnitude increased with age. These cross-reactive antibodies were produced by single memory B-cells present in these donors, and either bind to epitopes on HA1 which are shared within different H1 strains (homosubtypic response) or shared between different subtypes (heterosubtypic response). PMID:23508915

  17. 2009 A(H1N1) seroconversion rates and risk factors among the general population in Vientiane Capital, Laos

    Kieffer, Alexia; Paboriboune, Phimpha; Crepey, Pascal; Flaissier, Bruno; Souvong, Vimalay; Steenkeste, Nicolas; Salez, Nicolas; Babin, François-Xavier; LONGUET, Christophe; Carrat, Fabrice; Flahault, Antoine; De Lamballerie, Xavier


    Objective To assess 2009 A(H1N1) seroconversion rates and their determinants within an unvaccinated population in Vientiane Capital, Laos. Methods CoPanFlu Laos, a general population cohort of 807 households and 4,072 participants was established in March 2010. Sociodemographic data, epidemiological data, and capillary blood samples were collected from all the household members in March, and again in October 2010, in order to assess the level of antibodies to 2009 A(H1N1) with the haemaggluti...

  18. Measured voluntary avoidance behaviour during the 2009 A/H1N1 epidemic.

    Bayham, Jude; Kuminoff, Nicolai V; Gunn, Quentin; Fenichel, Eli P


    Managing infectious disease is among the foremost challenges for public health policy. Interpersonal contacts play a critical role in infectious disease transmission, and recent advances in epidemiological theory suggest a central role for adaptive human behaviour with respect to changing contact patterns. However, theoretical studies cannot answer the following question: are individual responses to disease of sufficient magnitude to shape epidemiological dynamics and infectious disease risk? We provide empirical evidence that Americans voluntarily reduced their time spent in public places during the 2009 A/H1N1 swine flu, and that these behavioural shifts were of a magnitude capable of reducing the total number of cases. We simulate 10 years of epidemics (2003-2012) based on mixing patterns derived from individual time-use data to show that the mixing patterns in 2009 yield the lowest number of total infections relative to if the epidemic had occurred in any of the other nine years. The World Health Organization and other public health bodies have emphasized an important role for 'distancing' or non-pharmaceutical interventions. Our empirical results suggest that neglect for voluntary avoidance behaviour in epidemic models may overestimate the public health benefits of public social distancing policies. PMID:26511046

  19. Why are oseltamivir and zanamivir effective against the newly emerged influenza A virus (A/HIN1)?

    Kunqian Yu; Cheng Luo; Guangrong Qin; Zhijian Xu; Ning Li; Hong Liu; Xu Shen; Jianpeng Ma; Qinghua Wang; Caiguang Yang; Weiliang Zhu; Hualiang Jiang


    @@ Dear Editor, The current flu epidemic caused by influenza A H1N1 (A/H1N1) virus, which first appeared in Mexico emerged as a communicable human disease in late March and rapidly spread throughout the world in April 2009. Due to the rapid transport systems in modern times, the epi-demic affected about 121 countries in less than 4 months (

  20. Effectiveness of seasonal influenza vaccine in preventing laboratory-confirmed influenza in primary care in the United Kingdom: 2015/16 mid-season results.

    Pebody, Richard; Warburton, Fiona; Ellis, Joanna; Andrews, Nick; Potts, Alison; Cottrell, Simon; Johnston, Jillian; Reynolds, Arlene; Gunson, Rory; Thompson, Catherine; Galiano, Monica; Robertson, Chris; Mullett, David; Gallagher, Naomh; Sinnathamby, Mary; Yonova, Ivelina; Moore, Catherine; McMenamin, Jim; de Lusignan, Simon; Zambon, Maria


    In 2015/16, the influenza season in the United Kingdom was dominated by influenza A(H1N1)pdm09 circulation. Virus characterisation indicated the emergence of genetic clusters, with the majority antigenically similar to the current influenza A(H1N1)pdm09 vaccine strain. Mid-season vaccine effectiveness (VE) estimates show an adjusted VE of 41.5% (95% confidence interval (CI): 3.0-64.7) against influenza-confirmed primary care consultations and of 49.1% (95% CI: 9.3-71.5) against influenza A(H1N1)pdm09. These estimates show levels of protection similar to the 2010/11 season, when this strain was first used in the seasonal vaccine. PMID:27074651

  1. Identification of small molecules acting against H1N1 influenza A virus.

    Agamennone, Mariangela; Pietrantoni, Agostina; Superti, Fabiana


    Influenza virus represents a serious threat to public health. The lack of effective drugs against flu prompted researchers to identify more promising viral target. In this respect hemagglutinin (HA) can represent an interesting option because of its pivotal role in the infection process. With this aim we collected a small library of commercially available compounds starting from a large database and performing a diversity-based selection to reduce the number of screened compounds avoiding structural redundancy of the library. Selected compounds were tested for their hemagglutination-inhibiting (HI) ability against two different A/H1N1 viral strains (one of which is oseltamivir sensitive), and 17 of them showed the ability to interact with HA. Five drug-like molecules, in particular, were able to impair hemagglutination of both A/H1N1 viral strains under study and to inhibit cytopathic effect and hemolysis at sub-micromolar level. PMID:26655243

  2. The sorption of influenza viruses and antibiotics on carbon nanotubes and polyaniline nanocomposites

    The decontamination of the solutions from micropatogens and drug delivery are the important problems of modern life. It was shown that carbon nanotubes, polyaniline and their composites can interact with antibiotics-polypeptides and some viruses (pandemic strain of influenza viruses A(H1N1)v circulated in Russia in 2009-2010. During a short time drug and viruses can be absorbed by polyaniline and removed from aqueous solutions at the normal conditions. Polyaniline composites can be useful for the preparation of drug delivery and virus control filters and also in biotechnology for the improvement the methods of antibiotics purification.

  3. The sorption of influenza viruses and antibiotics on carbon nanotubes and polyaniline nanocomposites

    Ivanova, V T; Ilyna, M V; Kurochkina, Y E [D.I. Ivanovsky Research Institute of Virology RAMS, Gamaleya st, 16, Moscow 123098 (Russian Federation); Katrukha, G S [G.F.Gause Institute of New Antibiotics RAMS, Moscow 119021 (Russian Federation); Timofeeva, A V; Baratova, L A [A.N. Belozersky Research Institute for Physico-Chemical Biology, M.V.Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Sapurina, I Yu [Institute of Macromolecular Compounds RAS, 199004, St. Petersburgr. Bolshoy Pr.31 (Russian Federation); Ivanov, V F, E-mail: [A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, RAS, Leninsky prospect, 31, Moscow 119991 (Russian Federation)


    The decontamination of the solutions from micropatogens and drug delivery are the important problems of modern life. It was shown that carbon nanotubes, polyaniline and their composites can interact with antibiotics-polypeptides and some viruses (pandemic strain of influenza viruses A(H1N1)v circulated in Russia in 2009-2010. During a short time drug and viruses can be absorbed by polyaniline and removed from aqueous solutions at the normal conditions. Polyaniline composites can be useful for the preparation of drug delivery and virus control filters and also in biotechnology for the improvement the methods of antibiotics purification.

  4. A/H1N1 Vaccine Intentions in College Students: An Application of the Theory of Planned Behavior

    Agarwal, Vinita


    Objective: To test the applicability of the Theory of Planned Behavior (TPB) in college students who have not previously received the A/H1N1 vaccine. Participants: Undergraduate communication students at a metropolitan southern university. Methods: In January-March 2010, students from voluntarily participating communication classes completed a…

  5. Antibody Response After a Single Dose of an AS03-Adjuvanted Split-Virion Influenza A (H1N1) Vaccine in Heart Transplant Recipients

    Meyer, Sven; Adam, Matti; Schweiger, Brunhilde; Ilchmann, Corina; Eulenburg, Christine; Sattinger, Edgar; Runte, Hendrik; Schlueter, Michael; Deuse, Tobias; Reichenspurner, Hermann; Costard-Jaeckle, Angelika


    Background. Influenza A (H1N1) has emerged as a considerable threat for recipients of organ transplants. Vaccination against the novel influenza A (H1N1) virus has generally been advocated. There is limited experience with AS03-adjuvanted A/H1N1 pandemic influenza vaccines in immunosuppressed patien

  6. Factores asociados a la predisposición a vacunarse contra la gripe pandémica A/H1N1 en población adulta del Departamento de Salud de Elche (España: Influencia de las fuentes de información Factors associated with willingness to be vaccinated against pandemic flu A/H1N1 in the adult population of the Health Department of Elche (Spain: The influence of sources of information

    J. Tuells


    Full Text Available Fundamento. Evaluar en población general las fuentes de información, actitudes y predisposición hacia la vacunación contra la gripe pandémica A/H1N1 de 2009. Métodos. Estudio descriptivo de carácter transversal realizado entre el 25 de noviembre y 30 de diciembre de 2009 mediante entrevista personal cara a cara a una muestra aleatoria (826 de adultos residentes en el Departamento de Salud de Elche (España. Resultados. Los encuestados manifestaron que la televisión (57% y el médico de familia (47,9% eran su fuente principal de información sobre vacunas. El 82,2% tenía una buena opinión sobre las vacunas, un 30,5% percibía la gripe A/H1N1 como más grave que la estacional, siendo esta percepción creciente entre los de mayor edad y con menos estudios. Un 25,4% de encuestados sentía preocupación por padecerla, sobre todo los de menor nivel educativo. Un 42,1% manifiesta su buena predisposición para vacunarse contra la gripe estacional, disminuyendo hasta un 18,4% la intención hacia la gripe A/H1N1. La predisposición hacia la vacunación crece con la edad y en el caso de la gripe A/H1N1 decrece a mayor nivel educativo. El médico de familia es la fuente de información más determinante para inmunizarse frente a gripe estacional (OR 1,43 y gripe A/H1N1 (OR 2,47. Conclusiones. Existe baja aceptabilidad de la vacuna pandémica y baja percepción de gravedad sobre la gripe A/H1N1. La experiencia previa de vacunación ante gripe estacional predispone hacia la inmunización contra gripe A/H1N1. Aunque los medios de comunicación encabezan la fuente de información más usual durante este episodio, la influencia del médico de familia en la decisión de vacunarse resulta significativa.Background. To assess, in the general population, the information sources, attitudes and willingness to be vaccinated against pandemic influenza A/H1N1 in 2009. Methods. We carried out a cross sectional study between 25th November and 30th December 2009

  7. Incidence and epidemiology of hospitalized influenza cases in rural Thailand during the influenza A (H1N1pdm09 pandemic, 2009-2010.

    Henry C Baggett

    Full Text Available BACKGROUND: Data on the burden of the 2009 influenza pandemic in Asia are limited. Influenza A(H1N1pdm09 was first reported in Thailand in May 2009. We assessed incidence and epidemiology of influenza-associated hospitalizations during 2009-2010. METHODS: We conducted active, population-based surveillance for hospitalized cases of acute lower respiratory infection (ALRI in all 20 hospitals in two rural provinces. ALRI patients were sampled 1∶2 for participation in an etiology study in which nasopharyngeal swabs were collected for influenza virus testing by PCR. RESULTS: Of 7,207 patients tested, 902 (12.5% were influenza-positive, including 190 (7.8% of 2,436 children aged 75 years (407 per 100,000. The incidence of influenza A(H1N1pdm09 was 62 per 100,000 (214 per 100,000 in children <5 years. Eleven influenza-infected patients required mechanical ventilation, and four patients died, all adults with influenza A(H1N1pdm09 (1 or H3N2 (3. CONCLUSIONS: Influenza-associated hospitalization rates in Thailand during 2009-10 were substantial and exceeded rates described in western countries. Influenza A(H1N1pdm09 predominated, but H3N2 also caused notable morbidity. Expanded influenza vaccination coverage could have considerable public health impact, especially in young children.

  8. [Genetic Diversity and Evolution of the M Gene of Human Influenza A Viruses from 2009 to 2013 in Hangzhou, China].

    Shao, Tiejuan; Li, Jun; Pu, Xiaoying; Yu, Xinfen; Kou, Yu; Zhou, Yinyan; Qian, Xin


    We investigated the genetic diversity and evolution of the M gene of human influenza A viruses in Hangzhou (Zhejiang province, China) from 2009 to 2013, including subtypes of A(H1N1) pdm09 strains and seasonal A(H3N2) strains. Subtypes of analyzed viruses were identified by cell culture and real-time reverse transcription-polymerase chain reaction, followed by cloning, sequencing and phylogenetic analyses of the M gene. Assessment of 5675 throat swabs revealed a positive rate for the influenza virus of 20.46%, and 827 cases were diagnosed as. infections due to influenza A viruses. Seventy-six influenza-A strains were selected randomly from nine stages during six phases of a virus epidemic. Sequences of the M gene showed high homology among six epidemics with identities of amino-acid sequences of 98.98-100%. All strains contained the adamantine-resistant mutation S31N in its M2 protein. Two of the A(H1N1)pdm09 strains had double mutants of V27A/S31N or V271/S31N. One of the seasonal A(H3N2) viruses had another form of double-mutant R45H/S31N. Evolutionary rate of the M gene was much lower than that of the HA gene and NA gene. Compared with A(H3N2) strains, higher positive pressure on the M1 and M2 proteins of A(H1N1) pdm09 viruses was observed. Separate analyses of M1 and M2 proteins revealed very different selection pressures. Knowledge of the genetic diversity and evolution of the M gene of human influenza-A viruses will be valuable for the control and prevention of diseases. PMID:26164939

  9. The Possible Impact of Vaccination for Seasonal Influenza on Emergence of Pandemic Influenza via Reassortment

    Xu-Sheng Zhang; Richard Pebody; Daniela De Angelis; Peter J White; Andre Charlett; McCauley, John W.


    Background One pathway through which pandemic influenza strains might emerge is reassortment from coinfection of different influenza A viruses. Seasonal influenza vaccines are designed to target the circulating strains, which intuitively decreases the prevalence of coinfection and the chance of pandemic emergence due to reassortment. However, individual-based analyses on 2009 pandemic influenza show that the previous seasonal vaccination may increase the risk of pandemic A(H1N1) pdm09 infecti...

  10. Liver involvement during influenza infection: perspective on the 2009 influenza pandemic

    Papic, Neven; Pangercic, Ana; Vargovic, Martina; Barsic, Bruno; Vince, Adriana; Kuzman, Ilija


    Please cite this paper as: Papic et al. (2011) Liver involvement during influenza infection: perspective on the 2009 influenza pandemic. Influenza and Other Respiratory Viruses 6(3), e2–e5. Elevation of liver transaminase levels is a frequent observation during systemic infections. The aim of our study was to investigate liver damage during pandemic 2009 influenza A/H1N1 infection in comparison with seasonal influenza. Serum levels of aspartate aminotransferase, alanine aminotransferase, and gamma‐glutamyl transpeptidase (GGT) were significantly higher in patients with pandemic influenza compared to seasonal influenza, which was strongly correlated with hypoxia. Moreover, a positive correlation between C‐reactive protein and serum GGT, alkaline phosphatase, and lactate dehydrogenase was noticed. Our findings support the hypothesis that the pandemic 2009 influenza A/H1N1 is an illness with a significant immune response to infection leading to hepatocellular injury. PMID:21951624