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Sample records for annual influenza epidemic

  1. Can influenza epidemics be prevented by voluntary vaccination?

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    Raffaele Vardavas

    2007-05-01

    Full Text Available Previous modeling studies have identified the vaccination coverage level necessary for preventing influenza epidemics, but have not shown whether this critical coverage can be reached. Here we use computational modeling to determine, for the first time, whether the critical coverage for influenza can be achieved by voluntary vaccination. We construct a novel individual-level model of human cognition and behavior; individuals are characterized by two biological attributes (memory and adaptability that they use when making vaccination decisions. We couple this model with a population-level model of influenza that includes vaccination dynamics. The coupled models allow individual-level decisions to influence influenza epidemiology and, conversely, influenza epidemiology to influence individual-level decisions. By including the effects of adaptive decision-making within an epidemic model, we can reproduce two essential characteristics of influenza epidemiology: annual variation in epidemic severity and sporadic occurrence of severe epidemics. We suggest that individual-level adaptive decision-making may be an important (previously overlooked causal factor in driving influenza epidemiology. We find that severe epidemics cannot be prevented unless vaccination programs offer incentives. Frequency of severe epidemics could be reduced if programs provide, as an incentive to be vaccinated, several years of free vaccines to individuals who pay for one year of vaccination. Magnitude of epidemic amelioration will be determined by the number of years of free vaccination, an individuals' adaptability in decision-making, and their memory. This type of incentive program could control epidemics if individuals are very adaptable and have long-term memories. However, incentive-based programs that provide free vaccination for families could increase the frequency of severe epidemics. We conclude that incentive-based vaccination programs are necessary to control

  2. Forecasting influenza epidemics from multi-stream surveillance data in a subtropical city of China.

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    Pei-Hua Cao

    Full Text Available Influenza has been associated with heavy burden of mortality and morbidity in subtropical regions. However, timely forecast of influenza epidemic in these regions has been hindered by unclear seasonality of influenza viruses. In this study, we developed a forecasting model by integrating multiple sentinel surveillance data to predict influenza epidemics in a subtropical city Shenzhen, China.Dynamic linear models with the predictors of single or multiple surveillance data for influenza-like illness (ILI were adopted to forecast influenza epidemics from 2006 to 2012 in Shenzhen. Temporal coherence of these surveillance data with laboratory-confirmed influenza cases was evaluated by wavelet analysis and only the coherent data streams were entered into the model. Timeliness, sensitivity and specificity of these models were also evaluated to compare their performance.Both influenza virology data and ILI consultation rates in Shenzhen demonstrated a significant annual seasonal cycle (p<0.05 during the entire study period, with occasional deviations observed in some data streams. The forecasting models that combined multi-stream ILI surveillance data generally outperformed the models with single-stream ILI data, by providing more timely, sensitive and specific alerts.Forecasting models that combine multiple sentinel surveillance data can be considered to generate timely alerts for influenza epidemics in subtropical regions like Shenzhen.

  3. Using Clinicians’ Search Query Data to Monitor Influenza Epidemics

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    Santillana, Mauricio; Nsoesie, Elaine O.; Mekaru, Sumiko R.; Scales, David; Brownstein, John S.

    2014-01-01

    Search query information from a clinician's database, UpToDate, is shown to predict influenza epidemics in the United States in a timely manner. Our results show that digital disease surveillance tools based on experts' databases may be able to provide an alternative, reliable, and stable signal for accurate predictions of influenza outbreaks. PMID:25115873

  4. Using clinicians' search query data to monitor influenza epidemics.

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    Santillana, Mauricio; Nsoesie, Elaine O; Mekaru, Sumiko R; Scales, David; Brownstein, John S

    2014-11-15

    Search query information from a clinician's database, UpToDate, is shown to predict influenza epidemics in the United States in a timely manner. Our results show that digital disease surveillance tools based on experts' databases may be able to provide an alternative, reliable, and stable signal for accurate predictions of influenza outbreaks.

  5. An epidemic of influenza on Tristan da Cunha.

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    Mantle, J; Tyrrell, D A

    1973-03-01

    Respiratory disease on Tristan da Cunha has been observed since the islanders returned in 1962. An epidemic of unprecedented severity occurred in the winter of 1971 and involved 273 (96%) of 284 islanders, 92 of whom had two attacks.The epidemic was apparently introduced by the Tristania.The illness of both first and second attacks ranged from mild to severe but there were some differences. There were two deaths, both in elderly persons with chronic chest disease and heart failure. Serological evidence suggests that this was due to influenza A2 of the Hong Kong serotype H(3)N(2).

  6. A nosocomial outbreak of influenza during a period without influenza epidemic activity.

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    Horcajada, J P; Pumarola, T; Martínez, J A; Tapias, G; Bayas, J M; de la Prada, M; García, F; Codina, C; Gatell, J M; Jiménez de Anta, M T

    2003-02-01

    The objective of this study was to describe a nosocomial outbreak of influenza during a period without influenza epidemic activity in the community. Outbreak investigation was carried out in an infectious diseases ward of a tertiary hospital. Presence of two or more of the following symptoms were used to define influenza: cough, sore throat, myalgia and fever. Epidemiological survey, direct immunofluorescence, viral culture, polymerase chain reaction, haemagglutination-inhibition test in throat swabs and serology for respiratory viruses were performed. Twenty-nine of 57 healthcare workers (HCW) (51%) and eight of 23 hospitalised patients (34%) fulfilled the case definition. Sixteen HCW (55%) and three inpatients (37%) had a definitive diagnosis of influenza A virus infection (subtype H1N1). Among the symptomatic HCW, 93% had not been vaccinated against influenza that season. Affected inpatients were isolated and admissions in the ward were cancelled for 2 weeks. Symptomatic HCW were sent home for 1 week. On the seventeenth day of the outbreak the last case was declared. The incidence of cases in this outbreak of influenza, which occurred during a period without influenza epidemic activity in the community, was notably high. Epidemiological data suggest transmission from healthcare workers to inpatients. Most healthcare workers were not vaccinated against influenza. Vaccination programmes should be reinforced among healthcare workers.

  7. Deriving a model for influenza epidemics from historical data.

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    Ray, Jaideep; Lefantzi, Sophia

    2011-09-01

    In this report we describe how we create a model for influenza epidemics from historical data collected from both civilian and military societies. We derive the model when the population of the society is unknown but the size of the epidemic is known. Our interest lies in estimating a time-dependent infection rate to within a multiplicative constant. The model form fitted is chosen for its similarity to published models for HIV and plague, enabling application of Bayesian techniques to discriminate among infectious agents during an emerging epidemic. We have developed models for the progression of influenza in human populations. The model is framed as a integral, and predicts the number of people who exhibit symptoms and seek care over a given time-period. The start and end of the time period form the limits of integration. The disease progression model, in turn, contains parameterized models for the incubation period and a time-dependent infection rate. The incubation period model is obtained from literature, and the parameters of the infection rate are fitted from historical data including both military and civilian populations. The calibrated infection rate models display a marked difference in which the 1918 Spanish Influenza pandemic differed from the influenza seasons in the US between 2001-2008 and the progression of H1N1 in Catalunya, Spain. The data for the 1918 pandemic was obtained from military populations, while the rest are country-wide or province-wide data from the twenty-first century. We see that the initial growth of infection in all cases were about the same; however, military populations were able to control the epidemic much faster i.e., the decay of the infection-rate curve is much higher. It is not clear whether this was because of the much higher level of organization present in a military society or the seriousness with which the 1918 pandemic was addressed. Each outbreak to which the influenza model was fitted yields a separate set of

  8. On the relative role of different age groups in influenza epidemics

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    Colin J. Worby

    2015-12-01

    While the relative importance of different age groups in propagating influenza outbreaks varies, children aged 5–17 play the leading role during the largest influenza A epidemics. Extra vaccination efforts for this group may contribute to reducing the epidemic's impact in the whole community.

  9. Modeling the effects of annual influenza vaccination

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    Smith, D.J.; Ackley, D.H.; Forrest, S. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Computer Science; Perelson, A.S. [Los Alamos National Lab., NM (United States). Theoretical Div.

    1998-12-31

    Although influenza vaccine efficacy is 70--90% in young healthy first-time vaccinees, the efficacy in repeat vaccinees has varied considerably. In some studies, vaccine efficacy in repeat vaccinees was higher than in first-time vaccinees, whereas in other studies vaccine efficacy in repeat vaccinees was significantly lower than in first-time vaccinees and sometimes no higher than in unvaccinated controls. It is known that the closeness of the antigenic match between the vaccine strain and the epidemic virus is important for vaccine effectiveness. In this study the authors show that the antigenic differences between a first vaccine strain and a second vaccine strain, and between the first vaccine strain and the epidemic strain, might account for the observed variation in attack rate among two-time vaccinees.

  10. [Differences in influenza epidemics in Osaka City--epidemiological surveillance of infectious disease].

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    Murakami, T; Haruki, K; Seto, Y; Kimura, T; Shibe, K; Minoshiro, S

    1994-05-01

    Influenza viruses in outpatients with influenza symptoms in Osaka City were analyzed in an epidemiological surveillance of infectious disease between 1989 and 1993. During influenza epidemics a mixed prevalence of several types of influenza viruses existed. Three types of influenza viruses, AH1, AH3 and B, were isolated during the 1990/1991 season. Remarkably the three types of viruses were discovered in samplings collected on the same day and within a narrow area inside a radius of 800-1,000m from the surveyed hospitals. Different types of viruses were detected between brothers and among school children from same housing complexes. Influenza AH3 viruses detected in 1992/1993 season differed in antigenicity from those detected in the 1990/1991 and 1991/1992 seasons. Therefore it appears that mutation of the AH3 virus contributed to the large-scale influenza epidemic which occurred in the 1992/1993 season.

  11. Universal influenza vaccines, science fiction or soon reality?

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    R.D. de Vries (Rory); A.F. Altenburg; G.F. Rimmelzwaan (Guus)

    2015-01-01

    textabstractCurrently used influenza vaccines are only effective when the vaccine strains match the epidemic strains antigenically. To this end, seasonal influenza vaccines must be updated almost annually. Furthermore, seasonal influenza vaccines fail to afford protection against antigenically disti

  12. Sickness Absenteeism Rate in Iranian Schools during the 2009 Epidemic of Type a Influenza

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    Pourabbasi, Ata; Shirvani, Mahbubeh Ebrahimnegad; Khashayar, Patricia

    2012-01-01

    Influenza pandemic was a global event in 2009 and intraschool transmission was its main spread method. The present study was designed to evaluate the absenteeism rate during the type A influenza epidemic. Four hundred and eight students from both a guidance school and high school in the Iranian capital were recruited in this retrospective study.…

  13. Evolutionary Analysis of Inter-Farm Transmission Dynamics in a Highly Pathogenic Avian Influenza Epidemic

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    Bataille, A.; Meer, van der F.; Stegeman, A.; Koch, G.

    2011-01-01

    Phylogenetic studies have largely contributed to better understand the emergence, spread and evolution of highly pathogenic avian influenza during epidemics, but sampling of genetic data has never been detailed enough to allow mapping of the spatiotemporal spread of avian influenza viruses during a

  14. Annually repeated influenza vaccination improves humoral responses to several influenza virus strains in healthy elderly

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    I.A. de Bruijn (Iris); E.J. Remarque (Edmond); W.E.Ph. Beyer (Walter); S. le Cessie (Saskia); N. Masurel (Nic); G.L. Ligthart (Gerard)

    1997-01-01

    textabstractThe benefit of annually repeated influenza vaccination on antibody formation is still under debate. In this study the effect of annually repeated influenza vaccination on haemagglutination inhibiting (HI) antibody formation in the elderly is investigated. Between 1990 and 1993 healthy yo

  15. The 2012-2013 influenza epidemic and the role of osteopathic manipulative medicine.

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    Mueller, Donna M

    2013-09-01

    The 2012-2013 influenza epidemic arrived approximately 4 weeks early, augmented by an unusual variant type-A ("swine flu") strain that caused greater-than-normal illness and a lack of efficacy in vaccination against it. Tens of thousands of people die of influenza or related complications during a nonepidemic influenza season. Osteopathic medicine can substantially help to address the complications that result from influenza. For example, during the deadly 1918-1919 Spanish influenza pandemic, osteopaths reduced patient mortality and morbidity by using lymphatic treatment techniques. Use of osteopathic manipulative treatment with vaccination, antiviral therapy, and chemoprophylaxis has potential to save lives and reduce complications. The present article describes the role of osteopathic manipulative treatment in the management of influenza and highlights current issues surrounding the use of antiviral therapy.

  16. Diagnosis and antiviral intervention strategies for mitigating an influenza epidemic.

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    Robert Moss

    Full Text Available BACKGROUND: Many countries have amassed antiviral stockpiles for pandemic preparedness. Despite extensive trial data and modelling studies, it remains unclear how to make optimal use of antiviral stockpiles within the constraints of healthcare infrastructure. Modelling studies informed recommendations for liberal antiviral distribution in the pandemic phase, primarily to prevent infection, but failed to account for logistical constraints clearly evident during the 2009 H1N1 outbreaks. Here we identify optimal delivery strategies for antiviral interventions accounting for logistical constraints, and so determine how to improve a strategy's impact. METHODS AND FINDINGS: We extend an existing SEIR model to incorporate finite diagnostic and antiviral distribution capacities. We evaluate the impact of using different diagnostic strategies to decide to whom antivirals are delivered. We then determine what additional capacity is required to achieve optimal impact. We identify the importance of sensitive and specific case ascertainment in the early phase of a pandemic response, when the proportion of false-positive presentations may be high. Once a substantial percentage of ILI presentations are caused by the pandemic strain, identification of cases for treatment on syndromic grounds alone results in a greater potential impact than a laboratory-dependent strategy. Our findings reinforce the need for a decentralised system capable of providing timely prophylaxis. CONCLUSIONS: We address specific real-world issues that must be considered in order to improve pandemic preparedness policy in a practical and methodologically sound way. Provision of antivirals on the scale proposed for an effective response is infeasible using traditional public health outbreak management and contact tracing approaches. The results indicate to change the transmission dynamics of an influenza epidemic with an antiviral intervention, a decentralised system is required for

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

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    Fathudinova, Mohinav; Alimova, Barno; Rahimova, Halima

    2016-07-01

    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

  18. FluTE, a publicly available stochastic influenza epidemic simulation model.

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    Dennis L Chao

    2010-01-01

    Full Text Available Mathematical and computer models of epidemics have contributed to our understanding of the spread of infectious disease and the measures needed to contain or mitigate them. To help prepare for future influenza seasonal epidemics or pandemics, we developed a new stochastic model of the spread of influenza across a large population. Individuals in this model have realistic social contact networks, and transmission and infections are based on the current state of knowledge of the natural history of influenza. The model has been calibrated so that outcomes are consistent with the 1957/1958 Asian A(H2N2 and 2009 pandemic A(H1N1 influenza viruses. We present examples of how this model can be used to study the dynamics of influenza epidemics in the United States and simulate how to mitigate or delay them using pharmaceutical interventions and social distancing measures. Computer simulation models play an essential role in informing public policy and evaluating pandemic preparedness plans. We have made the source code of this model publicly available to encourage its use and further development.

  19. Diversity of influenza-like illness etiology in Polish Armed Forces in influenza epidemic season.

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    Kocik, Janusz; Niemcewicz, Marcin; Winnicka, Izabela; Michalski, Aleksander; Bielawska-Drózd, Agata; Kołodziej, Marcin; Joniec, Justyna; Cieślik, Piotr; Graniak, Grzegorz; Mirski, Tomasz; Gaweł, Jerzy; Bielecka-Oder, Anna; Kubiak, Leszek; Russell, Kevin

    2014-01-01

    The aim of this study was to conduct an epidemiological and laboratory surveillance of Influenza-Like Illnesses (ILI) in Polish Armed Forces, civilian military personnel and their families in 2011/2012 epidemic season, under the United States Department of Defense-Global Emerging Infections Surveillance and Response System (DoD-GEIS). ILI incidence data were analyzed in relation to age, gender, patient category as well as pathogen patterns. Multiple viral, bacterial and viral-bacterial co-infections were identified. Nose and throat swabs of active duty soldiers in the homeland country and in the NATO peacekeeping forces KFOR (Kosovo Force), as well as members of their families were tested for the presence of viral and bacterial pathogens. From October 2011 to May 2012, 416 specimens from ILI symptoms patients were collected and analyzed for the presence of viral and bacterial pathogens. Among viruses, coronavirus was the most commonly detected. In the case of bacterial infections, the most common pathogen was Staphylococcus aureus.

  20. The clinical usefulness of lymphocyte:monocyte ratios in differentiating influenza from viral non-influenza-like illnesses in hospitalized adults during the 2015 influenza A (H3N2) epidemic: the uniqueness of HPIV-3 mimicking influenza A.

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    Cunha, B A; Connolly, J J; Irshad, N

    2016-01-01

    During influenza epidemics, influenza-like illnesses (ILIs) viruses cocirculate with influenza strains. If positive, rapid influenza diagnostic tests (RIDTs) identify influenza A/B, but false-negative RIDTs require retesting by viral polymerase chain reaction (PCR). Patient volume limits testing during influenza epidemics, and non-specific laboratory findings have been used for presumptive diagnosis pending definitive viral testing. In adults, the most useful laboratory abnormalities in influenza include relative lymphopenia, monocytosis, and thrombocytopenia. Lymphocyte:monocyte (L:M) ratios may be even more useful. L:M ratios ILIs. During the 2015 influenza A (H3N2) epidemic at our hospital, we reviewed our experience with L:M ratios in 37 hospitalized adults with non-influenza viral ILIs. In hospitalized adults with non-influenza A ILIs, the L:M ratios were >2 with human metapneumovirus (hMPV), rhinoviruses/enteroviruses (R/E), and respiratory syncytial virus (RSV), but not human parainfluenza virus type 3 (HPIV-3), which had L:M ratios 3 days, whereas with HPIV-3, L:M ratios 3 days of hospitalization.

  1. Global Dynamics of Avian Influenza Epidemic Models with Psychological Effect

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    Sanhong Liu

    2015-01-01

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

  2. Surveillance and vaccine effectiveness of an influenza epidemic predominated by vaccine-mismatched influenza B/Yamagata-lineage viruses in Taiwan, 2011-12 season.

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    Yi-Chun Lo

    Full Text Available INTRODUCTION: The 2011-12 trivalent influenza vaccine contains a strain of influenza B/Victoria-lineage viruses. Despite free provision of influenza vaccine among target populations, an epidemic predominated by influenza B/Yamagata-lineage viruses occurred during the 2011-12 season in Taiwan. We characterized this vaccine-mismatched epidemic and estimated influenza vaccine effectiveness (VE. METHODS: Influenza activity was monitored through sentinel viral surveillance, emergency department (ED and outpatient influenza-like illness (ILI syndromic surveillance, and case-based surveillance of influenza with complications and deaths. VE against laboratory-confirmed influenza was evaluated through a case-control study on ILI patients enrolled into sentinel viral surveillance. Logistic regression was used to estimate VE adjusted for confounding factors. RESULTS: During July 2011-June 2012, influenza B accounted for 2,382 (72.5% of 3,285 influenza-positive respiratory specimens. Of 329 influenza B viral isolates with antigen characterization, 287 (87.2% were B/Yamagata-lineage viruses. Proportions of ED and outpatient visits being ILI-related increased from November 2011 to January 2012. Of 1,704 confirmed cases of influenza with complications, including 154 (9.0% deaths, influenza B accounted for 1,034 (60.7% of the confirmed cases and 103 (66.9% of the deaths. Reporting rates of confirmed influenza with complications and deaths were 73.5 and 6.6 per 1,000,000, respectively, highest among those aged ≥65 years, 50-64 years, 3-6 years, and 0-2 years. Adjusted VE was -31% (95% CI: -80, 4 against all influenza, 54% (95% CI: 3, 78 against influenza A, and -66% (95% CI: -132, -18 against influenza B. CONCLUSIONS: This influenza epidemic in Taiwan was predominated by B/Yamagata-lineage viruses unprotected by the 2011-12 trivalent vaccine. The morbidity and mortality of this vaccine-mismatched epidemic warrants careful consideration of introducing a

  3. Different responses of influenza epidemic to weather factors among Shanghai, Hong Kong, and British Columbia

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    Wang, Xi-Ling; Yang, Lin; He, Dai-Hai; Chiu, Alice PY; Chan, Kwok-Hung; Chan, King-Pan; Zhou, Maigeng; Wong, Chit-Ming; Guo, Qing; Hu, Wenbiao

    2017-02-01

    Weather factors have long been considered as key sources for regional heterogeneity of influenza seasonal patterns. As influenza peaks coincide with both high and low temperature in subtropical cities, weather factors may nonlinearly or interactively affect influenza activity. This study aims to assess the nonlinear and interactive effects of weather factors with influenza activity and compare the responses of influenza epidemic to weather factors in two subtropical regions of southern China (Shanghai and Hong Kong) and one temperate province of Canada (British Columbia). Weekly data on influenza activity and weather factors (i.e., mean temperature and relative humidity (RH)) were obtained from pertinent government departments for the three regions. Absolute humidity (AH) was measured by vapor pressure (VP), which could be converted from temperature and RH. Generalized additive models were used to assess the exposure-response relationship between weather factors and influenza virus activity. Interactions of weather factors were further assessed by bivariate response models and stratification analyses. The exposure-response curves of temperature and VP, but not RH, were consistent among three regions/cities. Bivariate response model revealed a significant interactive effect between temperature (or VP) and RH (P environmental conditions.

  4. Influenza epidemics in Iceland over 9 decades: changes in timing and synchrony with the United States and Europe.

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    Weinberger, Daniel M; Krause, Tyra Grove; Mølbak, Kåre; Cliff, Andrew; Briem, Haraldur; Viboud, Cécile; Gottfredsson, Magnus

    2012-10-01

    Influenza epidemics exhibit a strongly seasonal pattern, with winter peaks that occur with similar timing across temperate areas of the Northern Hemisphere. This synchrony could be influenced by population movements, environmental factors, host immunity, and viral characteristics. The historical isolation of Iceland and subsequent increase in international contacts make it an ideal setting to study epidemic timing. The authors evaluated changes in the timing and regional synchrony of influenza epidemics using mortality and morbidity data from Iceland, North America, and Europe during the period from 1915 to 2007. Cross-correlations and wavelet analyses highlighted 2 major changes in influenza epidemic patterns in Iceland: first was a shift from nonseasonal epidemics prior to the 1930s to a regular winter-seasonal pattern, and second was a change in the early 1990s when a 1-month lag between Iceland and the United States and Europe was no longer detectable with monthly data. There was a moderate association between increased synchrony and the number of foreign visitors to Iceland, providing a plausible explanation for the second shift in epidemic timing. This suggests that transportation might have a minor effect on epidemic timing, but efforts to restrict air travel during influenza epidemics would likely have a limited impact, even for island populations.

  5. Accurate estimation of influenza epidemics using Google search data via ARGO.

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    Yang, Shihao; Santillana, Mauricio; Kou, S C

    2015-11-24

    Accurate real-time tracking of influenza outbreaks helps public health officials make timely and meaningful decisions that could save lives. We propose an influenza tracking model, ARGO (AutoRegression with GOogle search data), that uses publicly available online search data. In addition to having a rigorous statistical foundation, ARGO outperforms all previously available Google-search-based tracking models, including the latest version of Google Flu Trends, even though it uses only low-quality search data as input from publicly available Google Trends and Google Correlate websites. ARGO not only incorporates the seasonality in influenza epidemics but also captures changes in people's online search behavior over time. ARGO is also flexible, self-correcting, robust, and scalable, making it a potentially powerful tool that can be used for real-time tracking of other social events at multiple temporal and spatial resolutions.

  6. Seasonal Influenza: An Overview

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    Li, Christina; Freedman, Marian

    2009-01-01

    Seasonal influenza is a major cause of morbidity and mortality in the United States. It also has major social and economic consequences in the form of high rates of absenteeism from school and work as well as significant treatment and hospitalization costs. In fact, annual influenza epidemics and the resulting deaths and lost days of productivity…

  7. Modelling influenza A(H1N1) 2009 epidemics using a random network in a distributed computing environment.

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    González-Parra, Gilberto; Villanueva, Rafael-J; Ruiz-Baragaño, Javier; Moraño, Jose-A

    2015-03-01

    In this paper we propose the use of a random network model for simulating and understanding the epidemics of influenza A(H1N1). The proposed model is used to simulate the transmission process of influenza A(H1N1) in a community region of Venezuela using distributed computing in order to accomplish many realizations of the underlying random process. These large scale epidemic simulations have recently become an important application of high-performance computing. The network model proposed performs better than the traditional epidemic model based on ordinary differential equations since it adjusts better to the irregularity of the real world data. In addition, the network model allows the consideration of many possibilities regarding the spread of influenza at the population level. The results presented here show how well the SEIR model fits the data for the AH1N1 time series despite the irregularity of the data and returns parameter values that are in good agreement with the medical data regarding AH1N1 influenza virus. This versatile network model approach may be applied to the simulation of the transmission dynamics of several epidemics in human networks. In addition, the simulation can provide useful information for the understanding, prediction and control of the transmission of influenza A(H1N1) epidemics.

  8. The Annual Burden of Seasonal Influenza in the US Veterans Affairs Population

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    Young-Xu, Yinong; Russo, Ellyn; Lee, Jason K. H.; Chit, Ayman

    2017-01-01

    Seasonal influenza epidemics have a substantial public health and economic burden in the United States (US). On average, over 200,000 people are hospitalized and an estimated 23,000 people die from respiratory and circulatory complications associated with seasonal influenza virus infections each year. Annual direct medical costs and indirect productivity costs across the US have been found to average respectively at $10.4 billion and $16.3 billion. The objective of this study was to estimate the economic impact of severe influenza-induced illness on the US Veterans Affairs population. The five-year study period included 2010 through 2014. Influenza-attributed outcomes were estimated with a statistical regression model using observed emergency department (ED) visits, hospitalizations, and deaths from the Veterans Health Administration of the Department of Veterans Affairs (VA) electronic medical records and respiratory viral surveillance data from the Centers for Disease Control and Prevention (CDC). Data from VA’s Managerial Cost Accounting system were used to estimate the costs of the emergency department and hospital visits. Data from the Bureau of Labor Statistics were used to estimate the costs of lost productivity; data on age at death, life expectancy and economic valuations for a statistical life year were used to estimate the costs of a premature death. An estimated 10,674 (95% CI 8,661–12,687) VA ED visits, 2,538 (95% CI 2,112–2,964) VA hospitalizations, 5,522 (95% CI 4,834–6,210) all-cause deaths, and 3,793 (95% CI 3,375–4,211) underlying respiratory or circulatory deaths (inside and outside VA) among adult Veterans were attributable to influenza each year from 2010 through 2014. The annual value of lost productivity amounted to $27 (95% CI $24–31) million and the annual costs for ED visits were $6.2 (95% CI $5.1–7.4) million. Ninety-six percent of VA hospitalizations resulted in either death or a discharge to home, with annual costs

  9. Did the 1918 influenza cause the twentieth century cardiovascular mortality epidemic in the United States?

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    Steven Tate

    2016-10-01

    Full Text Available During most of the twentieth century, cardiovascular mortality increased in the United States while other causes of death declined. By 1958, the age-standardized death rate (ASDR for cardiovascular causes for females was 1.84 times that for all other causes, combined (and, for males, 1.79×. Although contemporary observers believed that cardiovascular mortality would remain high, the late 1950s and early 1960s turned out to be the peak of a roughly 70-year epidemic. By 1988 for females (1986 for males, a spectacular decline had occurred, wherein the ASDR for cardiovascular causes was less than that for other causes combined. We discuss this phenomenon from a demographic point of view. We also test a hypothesis from the literature, that the 1918 influenza pandemic caused the cardiovascular mortality epidemic; we fail to find support.

  10. Genomic characterization of influenza A (H7N9) viruses isolated in Shenzhen, Southern China, during the second epidemic wave.

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    Fang, Shisong; Wang, Xin; Dong, Fangyuan; Jin, Tao; Liu, Guang; Lu, Xing; Peng, Bo; Wu, Weihua; Liu, Hui; Kong, Dongfeng; Tang, Xiujuan; Qin, Yanmin; Mei, Shujiang; Xie, Xu; He, Jianfan; Ma, Hanwu; Zhang, Renli; Cheng, Jinquan

    2016-08-01

    There were three epidemic waves of human infection with avian influenza A (H7N9) virus in 2013-2014. While many analyses of the genomic origin, evolution, and molecular characteristics of the influenza A (H7N9) virus have been performed using sequences from the first epidemic wave, genomic characterization of the virus from the second epidemic wave has been comparatively less reported. In this study, an in-depth analysis was performed with respect to the genomic characteristics of 11 H7N9 virus strains isolated from confirmed cases and four H7N9 virus strains isolated from environmental samples in Shenzhen during the second epidemic wave. Phylogenetic analysis demonstrated that six internal segments of the influenza A (H7N9) virus isolated from confirmed cases and environmental samples in Shenzhen were clustered into two different clades and that the origin of the influenza A (H7N9) virus isolated from confirmed cases in Shenzhen was different from that of viruses isolated during the first wave. In addition, H9N2 viruses, which were prevalent in southern China, played an important role in the reassortment of the influenza A (H7N9) virus isolated in Shenzhen. HA-R47K and -T122A, PB2-V139I, PB1-I397M, and NS1-T216P were the signature amino acids of the influenza A (H7N9) virus isolated from confirmed cases in Shenzhen. We found that the HA, NA, M, and PA genes of the A(H7N9) viruses underwent positive selection in the human population. Therefore, enhanced surveillance should be carried out to determine the origin and mode of transmission of the novel influenza A (H7N9) virus and to facilitate the formulation of effective policies for prevention and containment of a human infection epidemics.

  11. Farm Models and Eco-Health of Poultry Production Clusters (PPCs) following Avian Influenza Epidemics in Thailand

    OpenAIRE

    Worapol Aengwanich

    2014-01-01

    Thailand is located in Southeast Asia and is a country that was affected by highly pathogenic avian influenza (HPAI) epidemics during 2003–2004. Nevertheless, the Thai government’s issuance policy of strict control and prevention of the disease has resulted in efficient disease control of avian influenza (AI). Poultry farmers have been both positively and negatively affected by this policy. There are three poultry cluster models worthy of attention in Thailand: (1) egg chicken poultry cluster...

  12. Influenza Epidemics in Iceland Over 9 Decades: Changes in Timing and Synchrony With the United States and Europe

    OpenAIRE

    Weinberger, Daniel M.; Krause, Tyra Grove; Mølbak, Kåre; Cliff, Andrew; Briem, Haraldur; Viboud, Cécile; Gottfredsson, Magnus

    2012-01-01

    Influenza epidemics exhibit a strongly seasonal pattern, with winter peaks that occur with similar timing across temperate areas of the Northern Hemisphere. This synchrony could be influenced by population movements, environmental factors, host immunity, and viral characteristics. The historical isolation of Iceland and subsequent increase in international contacts make it an ideal setting to study epidemic timing. The authors evaluated changes in the timing and regional syn...

  13. Universal influenza vaccines, science fiction or soon reality?

    Science.gov (United States)

    de Vries, Rory D; Altenburg, Arwen F; Rimmelzwaan, Guus F

    2015-01-01

    Currently used influenza vaccines are only effective when the vaccine strains match the epidemic strains antigenically. To this end, seasonal influenza vaccines must be updated almost annually. Furthermore, seasonal influenza vaccines fail to afford protection against antigenically distinct pandemic influenza viruses. Because of an ever-present threat of the next influenza pandemic and the continuous emergence of drift variants of seasonal influenza A viruses, there is a need for an universal influenza vaccine that induces protective immunity against all influenza A viruses. Here, we summarize some of the efforts that are ongoing to develop universal influenza vaccines.

  14. Circulation of Antibodies Against Influenza Virus Hemagglutinins in the 2014/2015 Epidemic Season in Poland.

    Science.gov (United States)

    Kowalczyk, D; Szymański, K; Cieślak, K; Brydak, L B

    2017-02-09

    The aim of this study was to determine the level of anti-hemagglutinin antibodies in the serum of people in different age-groups during the 2014/2015 epidemic influenza season in Poland. A total of 1050 sera were tested. The level of anti-hemagglutinin antibodies was determined using the hemagglutinin inhibition test. The results provided information on the incidence of circulating A/California/7/2009(H1N1)pdm09, A/Texas/50/2012(H3N2), and B/Massachusetts/2/2012 viruses. The level of antibodies against influenza differed between age-groups. The protection rate was the highest for the antigen B/Massachusetts/2/2012, with the decreasing order of values in the following age-groups: ≥65 years (76.7 %), 15-25 years (72.7 %), and 0-4 years (62.0 %). The average values of the protection rate in other age-groups were as follows: 43.3 % in 22-64 years, 40% in 5-9 years, and 39.3 % in 45-64 years of age, while the lowest value of 22.7 % was in 10-14 years old subjects. In the 2014/2015 epidemic season in Poland only were 3.6 % of the population vaccinated. That is why the presented results could be interpreted as a response of the immune system of patients after infection caused by influenza virus.

  15. Phylogenetic analysis of influenza A viruses (H3N2 circulating in Zhytomyr region during 2013–2014 epidemic season

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    Boyalska O. G.

    2015-06-01

    Full Text Available Aim. To perform phylogenetic analysis of the hemagglutinin (HA and neuraminidase (NA genes of influenza A(H3N2 viruses circulating in the Zhytomyr region during 2013–2014 epidemic season. To make comparison of the HA and NA genes sequences of the Zhytomyr region isolates with the HA and NA genes sequences of influenza viruses circulating in the world. Methods. Laboratory diagnosis was conducted by real-time polymerase chain reaction (RT-PCR. In this study the sequencing and phylogenetic analysis were carried out. Results. For the first time the genes of influenza A(H3N2 viruses isolated in the Zhytomyr region during 2013–2014 epidemic season, coding hemagglutinin and neuraminidase were compared with their orthologs. According to the results of this comparison the phylogenetic tree was constructed. Additionally, the amino acid substitutions of the influenza viruses circulating in Ukraine and worldwide were analyzed. Conclusions. The nucleotide sequences of the influenza A(H3N2 viruses genes HA and NA isolated in the Zhytomyr region were identified. Based on the nucleotide sequences of HA and NA we constructed the influenza virus phylogenetic tree demonstrating that the virus isolated in the Zhytomyr region was closely related to the Ukrainian isolate from Kharkov and in the world to the isolates from Germany, Romania, Italy.

  16. Lessons from the Largest Epidemic of Avian Influenza Viruses in Taiwan, 2015.

    Science.gov (United States)

    Chang, Ching-Fen; King, Chwan-Chuen; Wan, Cho-Hua; Chang, Yun-Cheng; Chan, Ta-Chien; David Lee, Chang-Chun; Chou, Po-Hao Borris; Li, Zheng-Rong Tiger; Li, Yao-Tsun; Tseng, Tzu-Jung; Lee, Pei-Fen; Chang, Chuan-Hsiung

    2016-05-01

    The largest epidemic of avian influenza (AI) in history attacked poultry and wild birds throughout Taiwan starting January 6, 2015. This study analyzed surveillance results, epidemiologic characteristics, and viral sequences by using government-released information, with the intention to provide recommendations to minimize future pandemic influenza. The H5 clade 2.3.4.4 highly pathogenic AI viruses (HPAIVs) had not been detected in Taiwan before 2015. During this epidemic, four types of etiologic agents were identified: the three novel subtypes H5N2, H5N8, and H5N3 clade 2.3.4.4 HPAIVs and one endemic chicken H5N2 subtype (Mexican-like lineage) of low pathogenic AI viruses. Cocirculation of mixed subtypes also occurred, with H5N2 clade 2.3.4.4 HPAIVs accompanied by the H5N8 and H5N3 subtypes or old H5N2 viruses in the same farm. More than 90% of domestic geese died from this AI epidemic; geese were affected the most at the early outbreaks. The epidemic peaked in mid-January for all three novel H5 subtypes. Spatial epidemiology found that most affected areas were located in southwestern coastal areas. In terrestrial poultry (mostly chickens), different geographic distributions of AI virus subtypes were detected, with hot spots of H5N2 clade 2.3.4.4 vs. past-endemic old H5N2 viruses in Changhwa (P = 0.03) and Yunlin (P = 0.007) counties, respectively, of central Taiwan. Phylogenetic and sequence analyses of all the early 10 Taiwan H5 clade 2.3.4.4 isolates covering the three subtypes showed that they were very different from the HA of the past local H5 viruses from domestic ducks (75%-80%) and chickens (70%-75%). However, they had the highest sequence identity percentages (99.53%-100%), with the HA of A/crane/Kagoshima/KU13/2014(H5N8) isolated on December 7, 2014, in Japan being higher than those of recent American and Korean H5 HPAIVs [A/Northern pintail/Washington/40964/2014 (H5N2) and A/gyrfalcon/Washington/41088-6/2014 (H5N8): 99.02%-99.54% and A/Baikal teal

  17. How backyard poultry flocks influence the effort required to curtail avian influenza epidemics in commercial poultry flocks

    OpenAIRE

    2011-01-01

    This paper summarizes the evidence that the contribution of backyard poultry flocks to the on-going transmission dynamics of an avian influenza epidemic in commercial flocks is modest at best. Nevertheless, while disease control strategies need not involve the backyard flocks, an analysis of the contribution of each element of the next generation matrix to the basic reproduction number indicates that models which ignores the contribution of backyard flocks in estimating the effort required of...

  18. Reconstruction of epidemic curves for pandemic influenza A (H1N1 2009 at city and sub-city levels

    Directory of Open Access Journals (Sweden)

    Wong Ngai Sze

    2010-11-01

    Full Text Available Abstract To better describe the epidemiology of influenza at local level, the time course of pandemic influenza A (H1N1 2009 in the city of Hong Kong was reconstructed from notification data after decomposition procedure and time series analysis. GIS (geographic information system methodology was incorporated for assessing spatial variation. Between May and September 2009, a total of 24415 cases were successfully geocoded, out of 25473 (95.8% reports in the original dataset. The reconstructed epidemic curve was characterized by a small initial peak, a nadir followed by rapid rise to the ultimate plateau. The full course of the epidemic had lasted for about 6 months. Despite the small geographic area of only 1000 Km2, distinctive spatial variation was observed in the configuration of the curves across 6 geographic regions. With the relatively uniform physical and climatic environment within Hong Kong, the temporo-spatial variability of influenza spread could only be explained by the heterogeneous population structure and mobility patterns. Our study illustrated how an epidemic curve could be reconstructed using regularly collected surveillance data, which would be useful in informing intervention at local levels.

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

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    Li KS

    2007-11-01

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

  20. Reconstructing the 2003/2004 H3N2 influenza epidemic in Switzerland with a spatially explicit, individual-based model

    Directory of Open Access Journals (Sweden)

    Zinsstag Jakob

    2011-05-01

    Full Text Available Abstract Background Simulation models of influenza spread play an important role for pandemic preparedness. However, as the world has not faced a severe pandemic for decades, except the rather mild H1N1 one in 2009, pandemic influenza models are inherently hypothetical and validation is, thus, difficult. We aim at reconstructing a recent seasonal influenza epidemic that occurred in Switzerland and deem this to be a promising validation strategy for models of influenza spread. Methods We present a spatially explicit, individual-based simulation model of influenza spread. The simulation model bases upon (i simulated human travel data, (ii data on human contact patterns and (iii empirical knowledge on the epidemiology of influenza. For model validation we compare the simulation outcomes with empirical knowledge regarding (i the shape of the epidemic curve, overall infection rate and reproduction number, (ii age-dependent infection rates and time of infection, (iii spatial patterns. Results The simulation model is capable of reproducing the shape of the 2003/2004 H3N2 epidemic curve of Switzerland and generates an overall infection rate (14.9 percent and reproduction numbers (between 1.2 and 1.3, which are realistic for seasonal influenza epidemics. Age and spatial patterns observed in empirical data are also reflected by the model: Highest infection rates are in children between 5 and 14 and the disease spreads along the main transport axes from west to east. Conclusions We show that finding evidence for the validity of simulation models of influenza spread by challenging them with seasonal influenza outbreak data is possible and promising. Simulation models for pandemic spread gain more credibility if they are able to reproduce seasonal influenza outbreaks. For more robust modelling of seasonal influenza, serological data complementing sentinel information would be beneficial.

  1. Farm Models and Eco-Health of Poultry Production Clusters (PPCs following Avian Influenza Epidemics in Thailand

    Directory of Open Access Journals (Sweden)

    Worapol Aengwanich

    2014-04-01

    Full Text Available Thailand is located in Southeast Asia and is a country that was affected by highly pathogenic avian influenza (HPAI epidemics during 2003–2004. Nevertheless, the Thai government’s issuance policy of strict control and prevention of the disease has resulted in efficient disease control of avian influenza (AI. Poultry farmers have been both positively and negatively affected by this policy. There are three poultry cluster models worthy of attention in Thailand: (1 egg chicken poultry clusters over ponds; (2 egg chicken poultry clusters in coops raised from the ground and managed by a cooperative; and (3 poultry clusters in closed coops under contract with the private sector. Following the AI epidemics, additional poultry husbandry and biosecurity systems were developed, thereby generating income and improving the quality of life for poultry farmers. Nevertheless, raising large clusters of poultry in the same area results in disadvantages, particularly problems with both air and water pollution, depending upon the environments of each poultry model. Furthermore, the government’s policy for controlling AI during epidemics has had a negative effect on the relationship between officials and farmers, due to poultry destruction measures.

  2. How backyard poultry flocks influence the effort required to curtail avian influenza epidemics in commercial poultry flocks.

    Science.gov (United States)

    Smith, G; Dunipace, S

    2011-06-01

    This paper summarizes the evidence that the contribution of backyard poultry flocks to the on-going transmission dynamics of an avian influenza epidemic in commercial flocks is modest at best. Nevertheless, while disease control strategies need not involve the backyard flocks, an analysis of the contribution of each element of the next generation matrix to the basic reproduction number indicates that models which ignores the contribution of backyard flocks in estimating the effort required of strategies focused one host type (e.g. commercial flocks only) necessarily underestimate the level of effort to an extent that may matter to policy makers.

  3. Burden of the 1999-2008 seasonal influenza epidemics in Italy: comparison with the H1N1v (A/California/07/09) pandemic.

    Science.gov (United States)

    Lai, Piero Luigi; Panatto, Donatella; Ansaldi, Filippo; Canepa, Paola; Amicizia, Daniela; Patria, Antonio Giuseppe; Gasparini, Roberto

    2011-01-01

    Despite preventive efforts, seasonal influenza epidemics are responsible for substantial morbidity and mortality every year worldwide, including developed countries. The A/H1N1v pandemic imposed a considerable healthcare and economic burden. In order to obtain an accurate estimate of the economic burden of influenza, and hence to guide policymakers effectively, systematic studies are necessary. To this end, data from epidemiological surveillance are essential. To estimate the impact of the 1999-2008 seasonal influenza epidemics and the H1N1v pandemic, we analyzed data from the Italian Influenza Surveillance System (CIRI NET). In the period 1999-2008, the Italian surveillance network consisted of sentinel general practitioners and pediatricians, who reported cases of Influenza-Like Illness (ILI) and Acute Respiratory Infections (ARI ) observed during their clinical practice from mid-October to late April each year; reports were sent to the Center for Research on Influenza and other Viral Infections (CIRI -IV). CIRI -IV receives data from 9 of the 20 Italian regions: Liguria, Abruzzo, Calabria, Friuli Venezia Giulia, Lombardy, Puglia, Sicily, Tuscany and Umbria. Previous estimates of influenza case costs were used in economic evaluations. Clinical-epidemiological and virological surveillance of the seasonal epidemics from 1999-2008 showed that the highest epidemic period was 2004-2005, when a new variant of the H3N2 influenza virus subtype emerged (A/California/07/04). Indeed, the highest peak of morbidity in the decade occurred in February 2005 (12.6 per 1,000 inhabitants). In 1999-2008, H1N1 subtype strains circulated and co-circulated with strains belonging to the H3N2 subtype and B type. Regarding B viruses in 2001-02, viruses belonged to the B/Victoria/02/07 lineage re-emerged, and in subsequent years co-circulated with viruses belonging to the B/Yamagata/lineage. The estimated costs of seasonal epidemics from 1999-2008 in Italy ranged from €15 to €20

  4. Estimation of force of infection based on different epidemiological proxies: 2009/2010 Influenza epidemic in Malta.

    Science.gov (United States)

    Marmara, V; Cook, A; Kleczkowski, A

    2014-12-01

    Information about infectious disease outbreaks is often gathered indirectly, from doctor's reports and health board records. It also typically underestimates the actual number of cases, but the relationship between the observed proxies and the numbers that drive the diseases is complicated, nonlinear and potentially time- and state-dependent. We use a combination of data collection from the 2009-2010 H1N1 outbreak in Malta, compartmental modelling and Bayesian inference to explore the effect of using various sources of information (consultations, doctor's diagnose, swabbing and molecular testing) on estimation of the effective basic reproduction ratio, R(t). Different proxies and different sampling rates (daily and weekly) lead to similar behaviour of R(t) as the epidemic unfolds, although individual parameters (force of infection, length of latent and infectious period) vary. We also demonstrate that the relationship between different proxies varies as epidemic progresses, with the first period characterised by high ratio of consultations and influenza diagnoses to actual confirmed cases of H1N1. This has important consequences for modelling that is based on reconstructing influenza cases from doctor's reports.

  5. Human Infection with Influenza A(H7N9) Virus during 3 Major Epidemic Waves, China, 2013–2015

    Science.gov (United States)

    Wu, Peng; Peng, Zhibin; Fang, Vicky J.; Feng, Luzhao; Tsang, Tim K.; Jiang, Hui; Lau, Eric H.Y.; Yang, Juan; Zheng, Jiandong; Qin, Ying; Li, Zhongjie; Leung, Gabriel M.; Cowling, Benjamin J.

    2016-01-01

    Since March 2013, a novel influenza A(H7N9) virus has caused 3 epidemic waves of human infection in mainland China. We analyzed data from patients with laboratory-confirmed influenza A(H7N9) virus infection to estimate the risks for severe outcomes after hospitalization across the 3 waves. We found that hospitalized patients with confirmed infections in waves 2 and 3 were younger and more likely to be residing in small cities and rural areas than were patients in wave 1; they also had a higher risk for death, after adjustment for age and underlying medical conditions. Risk for death among hospitalized patients during waves 2 and 3 was lower in Jiangxi and Fujian Provinces than in eastern and southern provinces. The variation in risk for death among hospitalized case-patients in different areas across 3 epidemic waves might be associated with differences in case ascertainment, changes in clinical management, or virus genetic diversity. PMID:27191934

  6. Estimation of force of infection based on different epidemiological proxies: 2009/2010 Influenza epidemic in Malta

    Directory of Open Access Journals (Sweden)

    V. Marmara

    2014-12-01

    Full Text Available Information about infectious disease outbreaks is often gathered indirectly, from doctor's reports and health board records. It also typically underestimates the actual number of cases, but the relationship between the observed proxies and the numbers that drive the diseases is complicated, nonlinear and potentially time- and state-dependent. We use a combination of data collection from the 2009–2010 H1N1 outbreak in Malta, compartmental modelling and Bayesian inference to explore the effect of using various sources of information (consultations, doctor's diagnose, swabbing and molecular testing on estimation of the effective basic reproduction ratio, Rt. Different proxies and different sampling rates (daily and weekly lead to similar behaviour of Rt as the epidemic unfolds, although individual parameters (force of infection, length of latent and infectious period vary. We also demonstrate that the relationship between different proxies varies as epidemic progresses, with the first period characterised by high ratio of consultations and influenza diagnoses to actual confirmed cases of H1N1. This has important consequences for modelling that is based on reconstructing influenza cases from doctor's reports.

  7. Influenza excess mortality from 1950-2000 in tropical Singapore.

    Directory of Open Access Journals (Sweden)

    Vernon J Lee

    Full Text Available INTRODUCTION: Tropical regions have been shown to exhibit different influenza seasonal patterns compared to their temperate counterparts. However, there is little information about the burden of annual tropical influenza epidemics across time, and the relationship between tropical influenza epidemics compared with other regions. METHODS: Data on monthly national mortality and population was obtained from 1947 to 2003 in Singapore. To determine excess mortality for each month, we used a moving average analysis for each month from 1950 to 2000. From 1972, influenza viral surveillance data was available. Before 1972, information was obtained from serial annual government reports, peer-reviewed journal articles and press articles. RESULTS: The influenza pandemics of 1957 and 1968 resulted in substantial mortality. In addition, there were 20 other time points with significant excess mortality. Of the 12 periods with significant excess mortality post-1972, only one point (1988 did not correspond to a recorded influenza activity. For the 8 periods with significant excess mortality periods before 1972 excluding the pandemic years, 2 years (1951 and 1953 had newspaper reports of increased pneumonia deaths. Excess mortality could be observed in almost all periods with recorded influenza outbreaks but did not always exceed the 95% confidence limits of the baseline mortality rate. CONCLUSION: Influenza epidemics were the likely cause of most excess mortality periods in post-war tropical Singapore, although not every epidemic resulted in high mortality. It is therefore important to have good influenza surveillance systems in place to detect influenza activity.

  8. High burden of non-influenza viruses in influenza-like illness in the early weeks of H1N1v epidemic in France.

    Directory of Open Access Journals (Sweden)

    Nathalie Schnepf

    Full Text Available BACKGROUND: Influenza-like illness (ILI may be caused by a variety of pathogens. Clinical observations are of little help to recognise myxovirus infection and implement appropriate prevention measures. The limited use of molecular tools underestimates the role of other common pathogens. OBJECTIVES: During the early weeks of the 2009-2010 flu pandemic, a clinical and virological survey was conducted in adult and paediatric patients with ILI referred to two French University hospitals in Paris and Tours. Aims were to investigate the different pathogens involved in ILI and describe the associated symptoms. METHODS: H1N1v pandemic influenza diagnosis was performed with real time RT-PCR assay. Other viral aetiologies were investigated by the molecular multiplex assay RespiFinder19®. Clinical data were collected prospectively by physicians using a standard questionnaire. RESULTS: From week 35 to 44, endonasal swabs were collected in 413 patients. Overall, 68 samples (16.5% were positive for H1N1v. In 13 of them, other respiratory pathogens were also detected. Among H1N1v negative samples, 213 (61.9% were positive for various respiratory agents, 190 in single infections and 23 in mixed infections. The most prevalent viruses in H1N1v negative single infections were rhinovirus (62.6%, followed by parainfluenza viruses (24.2% and adenovirus (5.3%. 70.6% of H1N1v cases were identified in patients under 40 years and none after 65 years. There was no difference between clinical symptoms observed in patients infected with H1N1v or with other pathogens. CONCLUSION: Our results highlight the high frequency of non-influenza viruses involved in ILI during the pre-epidemic period of a flu alert and the lack of specific clinical signs associated with influenza infections. Rapid diagnostic screening of a large panel of respiratory pathogens may be critical to define and survey the epidemic situation and to provide critical information for patient management.

  9. Estimating the per-contact probability of infection by highly pathogenic avian influenza (H7N7) virus during the 2003 epidemic in the Netherlands.

    NARCIS (Netherlands)

    Ssematimba, A.; Elbers, A.R.W.; Hagenaars, T.H.J.; Jong, de M.C.M.

    2012-01-01

    Estimates of the per-contact probability of transmission between farms of Highly Pathogenic Avian Influenza virus of H7N7 subtype during the 2003 epidemic in the Netherlands are important for the design of better control and biosecurity strategies. We used standardized data collected during the epid

  10. Performance of gross lesions at postmortem for the detection of outbreaks during the avian influenza A (H7N7) epidemic in the Netherlands in 2003

    NARCIS (Netherlands)

    Elbers, A.R.W.; Kamps, B.; Koch, G.

    2004-01-01

    A total of 123 submissions (on average, five birds per submission) from poultry flocks with a suspicion of an infection with highly pathogenic avian influenza virus were investigated at postmortem during the 2003 epidemic in The Netherlands. A total of 86 of these submissions were from infected floc

  11. Lessons from the epidemiological surveillance program, during the influenza A (H1N1 virus epidemic, in a reference university hospital of Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Maria Luiza Moretti

    2011-08-01

    Full Text Available INTRODUCTION: The case definition of influenza-like illness (ILI is a powerful epidemiological tool during influenza epidemics. METHODS: A prospective cohort study was conducted to evaluate the impact of two definitions used as epidemiological tools, in adults and children, during the influenza A H1N1 epidemic. Patients were included if they had upper respiratory samples tested for influenza by real-time reverse transcriptase polymerase chain reaction during two periods, using the ILI definition (coughing + temperature > 38ºC in period 1, and the definition of severe acute respiratory infection (ARS (coughing + temperature > 38ºC and dyspnoea in period 2. RESULTS: The study included 366 adults and 147 children, covering 243 cases of ILI and 270 cases of ARS. Laboratory confirmed cases of influenza were higher in adults (50% than in children (21.6% ( p < 0.0001 and influenza infection was more prevalent in the ILI definition (53% than ARS (24.4% (p < 0.0001. Adults reported more chills and myalgia than children (p = 0.0001. Oseltamivir was administered in 58% and 46% of adults and children with influenza A H1N1, respectively. The influenza A H1N1 case fatality rate was 7% in adults and 8.3% in children. The mean time from onset of illness until antiviral administration was 4 days. CONCLUSIONS: The modification of ILI to ARS definition resulted in less accuracy in influenza diagnosis and did not improve the appropriate time and use of antiviral medication.

  12. The epidemic wave of influenza A (H1N1) in Brazil, 2009.

    Science.gov (United States)

    Codeço, Cláudia Torres; Cordeiro, Josiane da Silva; Lima, Arthur Weiss da Silva; Colpo, Rodrigo Amarante; Cruz, Oswaldo Gonçalves; Coelho, Flavio Codeço; Luz, Paula Mendes; Struchiner, Claudio José; Barros, Fernando Ribeiro de

    2012-07-01

    This study describes the main features of pandemic influenza A (H1N1) in Brazil during 2009. Brazil is a large country that extends roughly from latitudes 5ºN to 34ºS. Brazil has tropical and sub-tropical climates, a heterogeneous population distribution, and intense urbanization in the southern portions of the country and along its Atlantic coast. Our analysis points to a wide variation in infection rates throughout the country, and includes both latitudinal effects and strong variations in detection rates. Two states (out of a total of 23) were responsible for 73% of all cases reported. Real time reproduction numbers demonstrate that influenza transmission was sustained in the country, beginning in May of 2009. Finally, this study discusses the challenges in understanding the infection dynamics of influenza and the adequacy of Brazil's influenza monitoring system.

  13. Influenza surveillance in Europe. Comparing intensity levels calculated using the Moving Epidemic Method.

    LENUS (Irish Health Repository)

    Vega, Tomás

    2015-05-30

    Although influenza-like illnesses (ILI) and acute respiratory illnesses (ARI) surveillance are well established in Europe, the comparability of intensity among countries and seasons remains an unresolved challenge.

  14. Waves of El Nino-southern Oscillation and Influenza Pandemics

    OpenAIRE

    Olusegun Steven Ayodele Oluwole

    2016-01-01

    Influenza pandemics have occurred at irregular intervals for over 500 years, unlike seasonal influenza epidemics which occur annually. Although the risk factors are known, the basis for the timing of influenza pandemic waves are unknown. Coherence of peaks of El Niño and influenza pandemic in 2009–2010, however, suggests that both waves are coupled. This study was done to determine the relation of influenza pandemics to the peaks and waveforms of El Niño southern oscillation (ENSO). ENSO cy...

  15. Detecting Robust Patterns in the Spread of Epidemics: A Case Study of Influenza in the United States and France

    CERN Document Server

    Crépey, Pascal

    2008-01-01

    In this paper, the authors develop a method of detecting correlations between epidemic patterns in different regions that are due to human movement and introduce a null model in which the travel-induced correlations are cancelled. They apply this method to the well-documented cases of seasonal influenza outbreaks in the United States and France. In the United States (using data for 1972-2002), the authors observed strong short-range correlations between several states and their immediate neighbors, as well as robust long-range spreading patterns resulting from large domestic air-traffic flows. The stability of these results over time allowed the authors to draw conclusions about the possible impact of travel restrictions on epidemic spread. The authors also applied this method to the case of France (1984-2004) and found that on the regional scale, there was no transportation mode that clearly dominated disease spread. The simplicity and robustness of this method suggest that it could be a useful tool for dete...

  16. Assortativity and the Probability of Epidemic Extinction: A Case Study of Pandemic Influenza A (H1N1-2009

    Directory of Open Access Journals (Sweden)

    Hiroshi Nishiura

    2011-01-01

    Full Text Available Unlike local transmission of pandemic influenza A (H1N1-2009, which was frequently driven by school children, most cases identified in long-distance intranational and international travelers have been adults. The present study examines the relationship between the probability of temporary extinction and the age-dependent next-generation matrix, focusing on the impact of assortativity. Preferred mixing captures as a good approximation the assortativity of a heterogeneously mixing population. We show that the contribution of a nonmaintenance host (i.e., a host type which cannot sustain transmission on its own to the risk of a major epidemic is greatly diminished as mixing patterns become more assortative, and in such a scenario, a higher proportion of non-maintenance hosts among index cases elevates the probability of extinction. Despite the presence of various other epidemiological factors that undoubtedly influenced the delay between first importations and the subsequent epidemic, these results suggest that the dominance of adults among imported cases represents one of the possible factors explaining the delays in geographic spread observed during the recent pandemic.

  17. Clinical Implications of Antiviral Resistance in Influenza

    OpenAIRE

    Li, Timothy C. M.; Chan, Martin C. W.; Nelson Lee

    2015-01-01

    Influenza is a major cause of severe respiratory infections leading to excessive hospitalizations and deaths globally; annual epidemics, pandemics, and sporadic/endemic avian virus infections occur as a result of rapid, continuous evolution of influenza viruses. Emergence of antiviral resistance is of great clinical and public health concern. Currently available antiviral treatments include four neuraminidase inhibitors (oseltamivir, zanamivir, peramivir, laninamivir), M2-inibitors (amantadin...

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

    Science.gov (United States)

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

    2010-09-01

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

  19. European Influenza Surveillance Scheme: annual report 2005-2006 influenza season.

    NARCIS (Netherlands)

    2007-01-01

    EISS is de organisatie die voor de EU en de WHO de verspreiding van influenza in Europa in de gaten houdt, mede met het oog op een mogelijke pandemie. Aan het EISS-netwerk deden tijdens het griepseizoen 2005-2006 25.000 peilstationartsen uit 29 landen mee. EISS bestrijkt een gebied met 489 miljoen i

  20. Real-time forecasting of an epidemic using a discrete time stochastic model: a case study of pandemic influenza (H1N1-2009

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    Nishiura Hiroshi

    2011-02-01

    Full Text Available Abstract Background Real-time forecasting of epidemics, especially those based on a likelihood-based approach, is understudied. This study aimed to develop a simple method that can be used for the real-time epidemic forecasting. Methods A discrete time stochastic model, accounting for demographic stochasticity and conditional measurement, was developed and applied as a case study to the weekly incidence of pandemic influenza (H1N1-2009 in Japan. By imposing a branching process approximation and by assuming the linear growth of cases within each reporting interval, the epidemic curve is predicted using only two parameters. The uncertainty bounds of the forecasts are computed using chains of conditional offspring distributions. Results The quality of the forecasts made before the epidemic peak appears largely to depend on obtaining valid parameter estimates. The forecasts of both weekly incidence and final epidemic size greatly improved at and after the epidemic peak with all the observed data points falling within the uncertainty bounds. Conclusions Real-time forecasting using the discrete time stochastic model with its simple computation of the uncertainty bounds was successful. Because of the simplistic model structure, the proposed model has the potential to additionally account for various types of heterogeneity, time-dependent transmission dynamics and epidemiological details. The impact of such complexities on forecasting should be explored when the data become available as part of the disease surveillance.

  1. Reverse Genetics Approaches for the Development of Influenza Vaccines

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    Aitor Nogales

    2016-12-01

    Full Text Available Influenza viruses cause annual seasonal epidemics and occasional pandemics of human respiratory disease. Influenza virus infections represent a serious public health and economic problem, which are most effectively prevented through vaccination. However, influenza viruses undergo continual antigenic variation, which requires either the annual reformulation of seasonal influenza vaccines or the rapid generation of vaccines against potential pandemic virus strains. The segmented nature of influenza virus allows for the reassortment between two or more viruses within a co-infected cell, and this characteristic has also been harnessed in the laboratory to generate reassortant viruses for their use as either inactivated or live-attenuated influenza vaccines. With the implementation of plasmid-based reverse genetics techniques, it is now possible to engineer recombinant influenza viruses entirely from full-length complementary DNA copies of the viral genome by transfection of susceptible cells. These reverse genetics systems have provided investigators with novel and powerful approaches to answer important questions about the biology of influenza viruses, including the function of viral proteins, their interaction with cellular host factors and the mechanisms of influenza virus transmission and pathogenesis. In addition, reverse genetics techniques have allowed the generation of recombinant influenza viruses, providing a powerful technology to develop both inactivated and live-attenuated influenza vaccines. In this review, we will summarize the current knowledge of state-of-the-art, plasmid-based, influenza reverse genetics approaches and their implementation to provide rapid, convenient, safe and more effective influenza inactivated or live-attenuated vaccines.

  2. ATTEMPTING TO PREDICT THE FATE OF AN ONGOING EPIDEMIC. LESSONS FROM A(H1N1 INFLUENZA IN USA.

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    Miguel Martín Martínez

    2009-01-01

    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.

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

    Science.gov (United States)

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

    2007-12-01

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

  4. Early warning of influenza epidemic based on influenza sentinel surveillance%一种基于流感哨点监测的流感预警分析方法

    Institute of Scientific and Technical Information of China (English)

    仝振东; 蒲柳艳; 虞奇跃; 王忠发; 王虹玲

    2011-01-01

    Objective To explorer the method of early warning of influenza epidemic based on influenza sentinel surveillance. Methods The Influenza-like illness (ILI) proportion of total outpatients and the positive rate of Influenza viruses for every week of a year in sentinel hospital were calculated. The correlation between them were analyzed. The threshold of ILI proportion for Influenza epidemic early warning were calculated by using the positive rate in peak season when it passed 40% of the maximum seasonal level. Results Tle average ILI proportion of total outpatients in 2010 was 1.62% (95% CI: 1.43% - 1.82% ), and the average positive rate of influenza viruses was 26.77% (95% CI: 20. 06% -33.49 % ). The positive rate threshold of influenza viruses during peak season was 32. 31%, ILI proportion threshold of 1.73 % was calculated for Influenza epidemic early warning. Conclusion Influenza epidemic early warning by using ILI proportion is simple, feasible, sensitive and specific. It is suitable for influenza epidemic early warning in local medical agencies conducting ILI sentinel surveillance.%目的 探讨利用流行性感冒(流感)哨点监测网络数据开展流感流行的预警方法.方法 选择流感监测质量较稳定的年份,计算各周相应的流感样病例(ILI)占哨点监测医院门诊就诊病例总数的比例(ILI%)和流感病毒检出阳性率及两者的相关性,利用流感病毒检出阳性率超过流行季峰值的40%界定流行高峰,换算出相应的ILI%预警阈值开展流感疫情预警工作.结果 舟山市2010年全年门诊就诊的ILI%平均为1.62%(95%CI:1.43%~1.82%),流感病毒检出阳性率平均为26.77%(95%CI:20.06%~33.49%),流感高峰出现时的流感病毒检出阳性率界值为32.31%,换算成ILI%=1.73%作为流感疫情预警阈值.结论 利用ILI%作为流感疫情的预警指标简单易行、灵敏特异,适用于建立运行流感样病例监测点的基层机构开展流感预警工作.

  5. History, Epidemic Evolution, and Model Burn-In for a Network of Annual Invasion: Soybean Rust.

    Science.gov (United States)

    Sanatkar, M R; Scoglio, C; Natarajan, B; Isard, S A; Garrett, K A

    2015-07-01

    Ecological history may be an important driver of epidemics and disease emergence. We evaluated the role of history and two related concepts, the evolution of epidemics and the burn-in period required for fitting a model to epidemic observations, for the U.S. soybean rust epidemic (caused by Phakopsora pachyrhizi). This disease allows evaluation of replicate epidemics because the pathogen reinvades the United States each year. We used a new maximum likelihood estimation approach for fitting the network model based on observed U.S. epidemics. We evaluated the model burn-in period by comparing model fit based on each combination of other years of observation. When the miss error rates were weighted by 0.9 and false alarm error rates by 0.1, the mean error rate did decline, for most years, as more years were used to construct models. Models based on observations in years closer in time to the season being estimated gave lower miss error rates for later epidemic years. The weighted mean error rate was lower in backcasting than in forecasting, reflecting how the epidemic had evolved. Ongoing epidemic evolution, and potential model failure, can occur because of changes in climate, host resistance and spatial patterns, or pathogen evolution.

  6. The role of backyard poultry flocks in the epidemic of highly pathogenic avian influenza virus (H7N7) in the Netherlands in 2003.

    Science.gov (United States)

    Bavinck, V; Bouma, A; van Boven, M; Bos, M E H; Stassen, E; Stegeman, J A

    2009-04-01

    In recent years, outbreaks of highly pathogenic avian influenza (HPAI) viruses have caused the death of millions of poultry and of more than 200 humans worldwide. A proper understanding of the transmission dynamics and risk factors for epidemic spread of these viruses is key to devising effective control strategies. The aim of this study was to quantify the epidemiological contributions of backyard flocks using data from the H7N7 HPAI epidemic in the Netherlands in 2003. A dataset was constructed in which flocks in the affected area were classified as susceptible (S), infected but not yet infectious (E), infectious (I), and removed (R). The analyses were based on a two-type SEIR epidemic model, with the two types representing commercial poultry farms and backyard poultry flocks. The analyses were aimed at estimation of the susceptibility (g) and infectiousness (f) of backyard flocks relative to commercial farms. The results show that backyard flocks were considerably less susceptible to infection than commercial farms (g = 0.014; 95%CI = 0.0071-0.023), while estimates of the relative infectiousness of backyard flocks varied widely (0 backyard flocks played a marginal role in the outbreak of highly pathogenic avian influenza in the Netherlands in 2003.

  7. Improving risk models for avian influenza: the role of intensive poultry farming and flooded land during the 2004 Thailand epidemic.

    Directory of Open Access Journals (Sweden)

    Thomas P Van Boeckel

    Full Text Available Since 1996 when Highly Pathogenic Avian Influenza type H5N1 first emerged in southern China, numerous studies sought risk factors and produced risk maps based on environmental and anthropogenic predictors. However little attention has been paid to the link between the level of intensification of poultry production and the risk of outbreak. This study revised H5N1 risk mapping in Central and Western Thailand during the second wave of the 2004 epidemic. Production structure was quantified using a disaggregation methodology based on the number of poultry per holding. Population densities of extensively- and intensively-raised ducks and chickens were derived both at the sub-district and at the village levels. LandSat images were used to derive another previously neglected potential predictor of HPAI H5N1 risk: the proportion of water in the landscape resulting from floods. We used Monte Carlo simulation of Boosted Regression Trees models of predictor variables to characterize the risk of HPAI H5N1. Maps of mean risk and uncertainty were derived both at the sub-district and the village levels. The overall accuracy of Boosted Regression Trees models was comparable to that of logistic regression approaches. The proportion of area flooded made the highest contribution to predicting the risk of outbreak, followed by the densities of intensively-raised ducks, extensively-raised ducks and human population. Our results showed that as little as 15% of flooded land in villages is sufficient to reach the maximum level of risk associated with this variable. The spatial pattern of predicted risk is similar to previous work: areas at risk are mainly located along the flood plain of the Chao Phraya river and to the south-east of Bangkok. Using high-resolution village-level poultry census data, rather than sub-district data, the spatial accuracy of predictions was enhanced to highlight local variations in risk. Such maps provide useful information to guide

  8. Improving risk models for avian influenza: the role of intensive poultry farming and flooded land during the 2004 Thailand epidemic.

    Science.gov (United States)

    Van Boeckel, Thomas P; Thanapongtharm, Weerapong; Robinson, Timothy; Biradar, Chandrashekhar M; Xiao, Xiangming; Gilbert, Marius

    2012-01-01

    Since 1996 when Highly Pathogenic Avian Influenza type H5N1 first emerged in southern China, numerous studies sought risk factors and produced risk maps based on environmental and anthropogenic predictors. However little attention has been paid to the link between the level of intensification of poultry production and the risk of outbreak. This study revised H5N1 risk mapping in Central and Western Thailand during the second wave of the 2004 epidemic. Production structure was quantified using a disaggregation methodology based on the number of poultry per holding. Population densities of extensively- and intensively-raised ducks and chickens were derived both at the sub-district and at the village levels. LandSat images were used to derive another previously neglected potential predictor of HPAI H5N1 risk: the proportion of water in the landscape resulting from floods. We used Monte Carlo simulation of Boosted Regression Trees models of predictor variables to characterize the risk of HPAI H5N1. Maps of mean risk and uncertainty were derived both at the sub-district and the village levels. The overall accuracy of Boosted Regression Trees models was comparable to that of logistic regression approaches. The proportion of area flooded made the highest contribution to predicting the risk of outbreak, followed by the densities of intensively-raised ducks, extensively-raised ducks and human population. Our results showed that as little as 15% of flooded land in villages is sufficient to reach the maximum level of risk associated with this variable. The spatial pattern of predicted risk is similar to previous work: areas at risk are mainly located along the flood plain of the Chao Phraya river and to the south-east of Bangkok. Using high-resolution village-level poultry census data, rather than sub-district data, the spatial accuracy of predictions was enhanced to highlight local variations in risk. Such maps provide useful information to guide intervention.

  9. Seasonality of Influenza A(H7N9) Virus in China—Fitting Simple Epidemic Models to Human Cases

    Science.gov (United States)

    Lin, Qianying; Lin, Zhigui; Chiu, Alice P. Y.; He, Daihai

    2016-01-01

    Background Three epidemic waves of influenza A(H7N9) (hereafter ‘H7N9’) human cases have occurred between March 2013 and July 2015 in China. However, the underlying transmission mechanism remains unclear. Our main objective is to use mathematical models to study how seasonality, secular changes and environmental transmission play a role in the spread of H7N9 in China. Methods Data on human cases and chicken cases of H7N9 infection were downloaded from the EMPRES-i Global Animal Disease Information System. We modelled on chicken-to-chicken transmission, assuming a constant ratio of 10−6 human case per chicken case, and compared the model fit with the observed human cases. We developed three different modified Susceptible-Exposed-Infectious-Recovered-Susceptible models: (i) a non-periodic transmission rate model with an environmental class, (ii) a non-periodic transmission rate model without an environmental class, and (iii) a periodic transmission rate model with an environmental class. We then estimated the key epidemiological parameters and compared the model fit using Akaike Information Criterion and Bayesian Information Criterion. Results Our results showed that a non-periodic transmission rate model with an environmental class provided the best model fit to the observed human cases in China during the study period. The estimated parameter values were within biologically plausible ranges. Conclusions This study highlighted the importance of considering secular changes and environmental transmission in the modelling of human H7N9 cases. Secular changes were most likely due to control measures such as Live Poultry Markets closures that were implemented during the initial phase of the outbreaks in China. Our results suggested that environmental transmission via viral shedding of infected chickens had contributed to the spread of H7N9 human cases in China. PMID:26963937

  10. Pandemic Influenza and Canada's Children

    Directory of Open Access Journals (Sweden)

    Joanne M Langley

    2006-01-01

    Full Text Available Paediatricians and others who care for children are familiar with the regular epidemic of respiratory illnesses that accompanies the annual visit of influenza virus each winter. In recent years, media interest in new strains of influenza has generated much public interest in, and often anxiety about, the threat of an influenza pandemic. Around the world, local, regional and national jurisdictions are engaged in contingency planning for the inevitable surge of illness, shortage of human and material resources, and societal disruption that is expected to accompany this event. In the present Paediatric Infectious Disease Note, we review briefly the potential implications of pandemic influenza for Canadian children, and the actions that paediatricians and others who care for children can take to prepare for this inevitable event.

  11. Effectiveness of A(H1N1)pdm09 influenza vaccine in adults recommended for annual influenza vaccination.

    NARCIS (Netherlands)

    Gefenaite, G.; Tacken, M.; Bos, J.; Stirbu-Wagner, I.; Korevaar, J.C.; Stolk, R.P.; Wolters, B.; Bijl, M.; Postma, M.J.; Wilschut, J.; Nichol, K.L.; Hak, E.

    2013-01-01

    Introduction: Because of variability in published A(H1N1)pdm09 influenza vaccine effectiveness estimates, we conducted a study in the adults belonging to the risk groups to assess the A(H1N1)pdm09 MF59-adjuvanted influenza vaccine effectiveness. Methods: VE against influenza and/or pneumonia was ass

  12. Effectiveness of A(H1N1)pdm09 influenza vaccine in adults recommended for annual influenza vaccination

    NARCIS (Netherlands)

    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

    2013-01-01

    INTRODUCTION: Because of variability in published A(H1N1)pdm09 influenza vaccine effectiveness estimates, we conducted a study in the adults belonging to the risk groups to assess the A(H1N1)pdm09 MF59-adjuvanted influenza vaccine effectiveness. METHODS: VE against influenza and/or pneumonia was ass

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

    Science.gov (United States)

    Majda-Stanisławska, Ewa; Sobieraj, Iwona

    2011-01-01

    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.

  14. Analysis of CDC social control measures using an agent-based simulation of an influenza epidemic in a city

    Directory of Open Access Journals (Sweden)

    Ettema Dick

    2011-07-01

    Full Text Available Abstract Background The transmission of infectious disease amongst the human population is a complex process which requires advanced, often individual-based, models to capture the space-time details observed in reality. Methods An Individual Space-Time Activity-based Model (ISTAM was applied to simulate the effectiveness of non-pharmaceutical control measures including: (1 refraining from social activities, (2 school closure and (3 household quarantine, for a hypothetical influenza outbreak in an urban area. Results Amongst the set of control measures tested, refraining from social activities with various compliance levels was relatively ineffective. Household quarantine was very effective, especially for the peak number of cases and total number of cases, with large differences between compliance levels. Household quarantine resulted in a decrease in the peak number of cases from more than 300 to around 158 for a 100% compliance level, a decrease of about 48.7%. The delay in the outbreak peak was about 3 to 17 days. The total number of cases decreased to a range of 3635-5403, that is, 63.7%-94.7% of the baseline value. When coupling control measures, household quarantine together with school closure was the most effective strategy. The resulting space-time distribution of infection in different classes of activity bundles (AB suggests that the epidemic outbreak is strengthened amongst children and then spread to adults. By sensitivity analysis, this study demonstrated that earlier implementation of control measures leads to greater efficacy. Also, for infectious diseases with larger basic reproduction number, the effectiveness of non-pharmaceutical measures was shown to be limited. Conclusions Simulated results showed that household quarantine was the most effective control measure, while school closure and household quarantine implemented together achieved the greatest benefit. Agent-based models should be applied in the future to evaluate the

  15. Evaluation of epidemic intelligence systems integrated in the early alerting and reporting project for the detection of A/H5N1 influenza events.

    Science.gov (United States)

    Barboza, Philippe; Vaillant, Laetitia; Mawudeku, Abla; Nelson, Noele P; Hartley, David M; Madoff, Lawrence C; Linge, Jens P; Collier, Nigel; Brownstein, John S; Yangarber, Roman; Astagneau, Pascal

    2013-01-01

    The objective of Web-based expert epidemic intelligence systems is to detect health threats. The Global Health Security Initiative (GHSI) Early Alerting and Reporting (EAR) project was launched to assess the feasibility and opportunity for pooling epidemic intelligence data from seven expert systems. EAR participants completed a qualitative survey to document epidemic intelligence strategies and to assess perceptions regarding the systems performance. Timeliness and sensitivity were rated highly illustrating the value of the systems for epidemic intelligence. Weaknesses identified included representativeness, completeness and flexibility. These findings were corroborated by the quantitative analysis performed on signals potentially related to influenza A/H5N1 events occurring in March 2010. For the six systems for which this information was available, the detection rate ranged from 31% to 38%, and increased to 72% when considering the virtual combined system. The effective positive predictive values ranged from 3% to 24% and F1-scores ranged from 6% to 27%. System sensitivity ranged from 38% to 72%. An average difference of 23% was observed between the sensitivities calculated for human cases and epizootics, underlining the difficulties in developing an efficient algorithm for a single pathology. However, the sensitivity increased to 93% when the virtual combined system was considered, clearly illustrating complementarities between individual systems. The average delay between the detection of A/H5N1 events by the systems and their official reporting by WHO or OIE was 10.2 days (95% CI: 6.7-13.8). This work illustrates the diversity in implemented epidemic intelligence activities, differences in system's designs, and the potential added values and opportunities for synergy between systems, between users and between systems and users.

  16. Suitability of PER.C6 cells to generate epidemic and pandemic influenza vaccine strains by reverse genetics

    NARCIS (Netherlands)

    Koudstaal, W.; Hartgroves, L.; Havenga, M.; Legastelois, I.; Ophorst, C.; Siewerts, M.; Zuijdgeest, D.; Vogels, R.; Custers, J.; Boer-Luijtze, E. de; Leeuw, O. de; Cornelissen, L.; Goudsmit, J.; Barclay, W.

    2009-01-01

    Reverse genetics, the generation of influenza viruses from cDNA, presents a rapid method for creating vaccine strains. The technique necessitates the use of cultured cells. Due to technical and regulatory requirements, the choice of cell lines for production of human influenza vaccines is limited. P

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

    Science.gov (United States)

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

    2014-02-01

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

  18. Individual Vaccination as Nash Equilibrium in a SIR Model with Application to the 2009-2010 Influenza A (H1N1) Epidemic in France.

    Science.gov (United States)

    Laguzet, Laetitia; Turinici, Gabriel

    2015-10-01

    The vaccination against ongoing epidemics is seldom compulsory but remains one of the most classical means to fight epidemic propagation. However, recent debates concerning the innocuity of vaccines and their risk with respect to the risk of the epidemic itself lead to severe vaccination campaign failures, and new mass behaviors appeared driven by individual self-interest. Prompted by this context, we analyze, in a Susceptible-Infected-Recovered model, whether egocentric individuals can reach an equilibrium with the rest of the society. Using techniques from the "Mean Field Games" theory, we extend previous results and show that an equilibrium exists and characterizes completely the individual best vaccination strategy (with or without discounting). We also compare with a strategy based only on overall societal optimization and exhibit a situation with nonnegative price of anarchy. Finally, we apply the theory to the 2009-2010 Influenza A (H1N1) vaccination campaign in France and hint that a group of individuals stopped vaccinating at levels that indicated a pessimistic perception of the risk of the vaccine.

  19. Influenza

    Directory of Open Access Journals (Sweden)

    Forleo-Neto Eduardo

    2003-01-01

    Full Text Available A influenza (gripe é doença infecciosa aguda de origem viral que acomete o trato respiratório e a cada inverno atinge mais de 100 milhões de pessoas na Europa, Japão e Estados Unidos, causando anualmente a morte de cerca de 20 a 40 mil pessoas somente neste último país. O agente etiológico é o Myxovirus influenzae, ou vírus da gripe. Este subdivide-se nos tipos A, B e C, sendo que apenas os do tipo A e B apresentam relevância clínica em humanos. O vírus influenza apresenta altas taxas de mutação, o que resulta freqüentemente na inserção de novas variantes virais na comunidade, para as quais a população não apresenta imunidade. São poucas as opções disponíveis para o controle da influenza. Dentre essas, a vacinação constitui a forma mais eficaz para o controle da doença e de suas complicações. Em função das mutações que ocorrem naturalmente no vírus influenza, recomenda-se que a vacinação seja realizada anualmente. No Brasil, segundo dados obtidos pelo Projeto VigiGripe - ligado à Universidade Federal de São Paulo -, verifica-se que a influenza apresenta pico de atividade entre os meses de maio e setembro. Assim, a época mais indicada para a vacinação corresponde aos meses de março e abril. Para o tratamento específico da influenza estão disponíveis quatro medicamentos antivirais: os fármacos clássicos amantadina e rimantidina e os antivirais de segunda geração oseltamivir e zanamivir. Os últimos, acrescentam alternativas para o tratamento da influenza e ampliam as opções disponíveis para o seu controle.

  20. Clinical and socioeconomic impact of seasonal and pandemic influenza in adults and the elderly.

    Science.gov (United States)

    Gasparini, Roberto; Amicizia, Daniela; Lai, Piero Luigi; Panatto, Donatella

    2012-01-01

    Influenza epidemics and pandemics carry a heavy socioeconomic burden. Hospitalization and treatment are more often necessary in high-risk patients, such as the elderly. However, the impact of influenza is not negligible even in adults, mainly because of lost productivity. The World Health Organization estimates that seasonal influenza causes 250,000-500,000 deaths worldwide each year; however, mortality may be very high in pandemic periods. Many estimates of the costs of seasonal influenza have been made in various socioeconomic contexts. For instance, among the adult population in Italy, a cost of €940.39 per case has been estimated. In the US, the average annual influenza burden in 18-49-y-old adults without underlying medical conditions is judged to include approximately 32,000 hospitalizations and 680 deaths. Estimating the influenza burden is a useful aid to determining the best influenza vaccination strategy and preventive and clinical treatments.

  1. Live Poultry Exposure and Public Response to Influenza A(H7N9 in Urban and Rural China during Two Epidemic Waves in 2013-2014.

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    Peng Wu

    Full Text Available The novel influenza A(H7N9 virus has caused 2013 spring and 2013-2014 winter waves of human infections since its first emergence in China in March 2013. Exposure to live poultry is a risk factor for H7N9 infection. Public psychobehavioral responses often change during progression of an epidemic.We conducted population-based surveys in southern China to examine human exposure to live poultry, and population psychological response and behavioral changes in the two waves. In Guangzhou, an urban area of Guangdong province, we collected data using telephone surveys with random digit dialing in May-June 2013 and again in December 2013 to January 2014. In Zijin county, a rural area of the same province, we used door-to-door surveys under a stratified sampling design in July 2013 and again in December 2013 to January 2014. All responses were weighted by age and sex to the respective adult populations.Around half of the urban respondents (53.8% reported having visited LPMs in the previous year in the first survey, around double that reported in the second survey (27.7%. In the rural surveys, around half of the participants reported raising backyard poultry in the past year in the first survey, increasing to 83.2% participants in the second survey. One third of urban subjects supported the permanent closure of LPMs in the first and second surveys, and factors associated with support for closure included female sex, higher level of worry towards H7N9, and worry induced by a hypothetical influenza-like illness.Our study indicated high human exposure to live poultry and low support for permanent closure of markets in both urban and rural residents regardless of increased worry during the epidemic.

  2. Live Poultry Exposure and Public Response to Influenza A(H7N9) in Urban and Rural China during Two Epidemic Waves in 2013-2014

    Science.gov (United States)

    Fang, Vicky J.; Li, Fu; Zeng, Lingjia; Wu, Joseph T.; Li, Zhongjie; Leung, Gabriel M.; Yu, Hongjie

    2015-01-01

    Background The novel influenza A(H7N9) virus has caused 2013 spring and 2013–2014 winter waves of human infections since its first emergence in China in March 2013. Exposure to live poultry is a risk factor for H7N9 infection. Public psychobehavioral responses often change during progression of an epidemic. Methods We conducted population-based surveys in southern China to examine human exposure to live poultry, and population psychological response and behavioral changes in the two waves. In Guangzhou, an urban area of Guangdong province, we collected data using telephone surveys with random digit dialing in May-June 2013 and again in December 2013 to January 2014. In Zijin county, a rural area of the same province, we used door-to-door surveys under a stratified sampling design in July 2013 and again in December 2013 to January 2014. All responses were weighted by age and sex to the respective adult populations. Findings Around half of the urban respondents (53.8%) reported having visited LPMs in the previous year in the first survey, around double that reported in the second survey (27.7%). In the rural surveys, around half of the participants reported raising backyard poultry in the past year in the first survey, increasing to 83.2% participants in the second survey. One third of urban subjects supported the permanent closure of LPMs in the first and second surveys, and factors associated with support for closure included female sex, higher level of worry towards H7N9, and worry induced by a hypothetical influenza-like illness. Conclusions Our study indicated high human exposure to live poultry and low support for permanent closure of markets in both urban and rural residents regardless of increased worry during the epidemic. PMID:26367002

  3. Efectos del Framing y representaciones sociales de epidemias sanitarias: El Caso de la Gripe A (Framing effects and social representations of health epidemics: The case of influenza A

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    Nahia Idoyaga

    2012-12-01

    Full Text Available This study analyzed how the mass media covered the influenza A (H1N1 pandemic and its influence on the social representation of the disease. Framing theory and a model of collective symbolic coping were both used to explain the influence of the mass media on social representation. The study was based on analyzing information on the influenza A pandemic provided by national newspapers in Mexico and Spain between 2009 and 2010. The results show that that the development of the crisis affected the use of different kinds of frames in the media. The use of different types of frames led to processes of collective symbolic coping, which are likely to alter the social representation of the epidemic. Data analysis using the Alceste program showed that the most prevalent frames used in the media were human interest and attributing responsibility to institutions. The theoretical implications of this study are discussed in terms of the relationship between framing, social representations and the role of the mass media. Applied implications concern the strategies identified in the media to deal with health crisi

  4. Evaluation of clinical features scoring system as screening tool for influenza A (H1N1 in epidemic situations

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    P Ranjan

    2012-01-01

    Full Text Available Background: Influenza A (H1N1 hit the headlines in recent times and created mass hysteria and general panic. The high cost and non-availability of diagnostic laboratory tests for swine flu, especially in the developing countries underlines the need of having a cheaper, easily available, yet reasonably accurate screening test. Aims: This study was carried out to develop a clinical feature-based scoring system (CFSS for influenza A (H1N1 and to evaluate its suitability as a screening tool when large numbers of influenza-like illness cases are suspect. Settings and Design: Clinical-record based study, carried out retrospectively in post-pandemic period on subject′s case-sheets who had been quarantined at IG International Airport′s quarantine center at Delhi. Materials and Methods: Clinical scoring of each suspected case was done by studying their case record sheet and compared with the results of RT-PCR. RT-PCR was used to confirm the diagnosis (Gold Standard. Statistical Analysis: We calculated sensitivity, specificity, positive and negative predictive values of the clinical feature-based scoring system (the proposed new screening tool at different cut-off values. The most discriminant cut-off value was determined by plotting the ROC curve. Results: Of the 638 suspected cases, 127 (20% were confirmed to have H1N1 by RT-PCR examination. On the basis of ROC, the most discriminant clinical feature score for diagnosing Influenza A was found to be 7, which yielded sensitivity, specificity, positive, and negative predictive values of 86%, 88%, 64%, and 96%, respectively. Conclusion: The clinical features scoring system (CFSS can be used as a valid and cost-effective tool for screening swine flu (influenza A (H1N1 cases from large number of influenza-like illness suspects.

  5. Clarithromycin Resistance Mechanisms of Epidemic β-Lactamase-Nonproducing Ampicillin-Resistant Haemophilus influenzae Strains in Japan.

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    Seyama, Shoji; Wajima, Takeaki; Nakaminami, Hidemasa; Noguchi, Norihisa

    2016-05-01

    The aim of this study was to clarify the clarithromycin resistance mechanisms of β-lactamase-nonproducing ampicillin-resistant Haemophilus influenzae strains. In all clarithromycin-resistant strains, the transcript level of acrB was significantly elevated, and these strains had a frameshift mutation in acrR Introduction of the acrR mutation into H. influenzae Rd generated a clarithromycin-resistant transformant with the same MIC as the donor strain. Our results indicate that the acrR mutation confers clarithromycin resistance by the increasing the transcription of acrB.

  6. Pros and cons of estimating the reproduction number from early epidemic growth rate of influenza A (H1N1 2009

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    Chowell Gerardo

    2010-01-01

    Full Text Available Abstract Background In many parts of the world, the exponential growth rate of infections during the initial epidemic phase has been used to make statistical inferences on the reproduction number, R, a summary measure of the transmission potential for the novel influenza A (H1N1 2009. The growth rate at the initial stage of the epidemic in Japan led to estimates for R in the range 2.0 to 2.6, capturing the intensity of the initial outbreak among school-age children in May 2009. Methods An updated estimate of R that takes into account the epidemic data from 29 May to 14 July is provided. An age-structured renewal process is employed to capture the age-dependent transmission dynamics, jointly estimating the reproduction number, the age-dependent susceptibility and the relative contribution of imported cases to secondary transmission. Pitfalls in estimating epidemic growth rates are identified and used for scrutinizing and re-assessing the results of our earlier estimate of R. Results Maximum likelihood estimates of R using the data from 29 May to 14 July ranged from 1.21 to 1.35. The next-generation matrix, based on our age-structured model, predicts that only 17.5% of the population will experience infection by the end of the first pandemic wave. Our earlier estimate of R did not fully capture the population-wide epidemic in quantifying the next-generation matrix from the estimated growth rate during the initial stage of the pandemic in Japan. Conclusions In order to quantify R from the growth rate of cases, it is essential that the selected model captures the underlying transmission dynamics embedded in the data. Exploring additional epidemiological information will be useful for assessing the temporal dynamics. Although the simple concept of R is more easily grasped by the general public than that of the next-generation matrix, the matrix incorporating detailed information (e.g., age-specificity is essential for reducing the levels of

  7. The application of GIS and RS for epidemics: a case study of the spread of highly pathogenic avian influenza in China in 2004-2005

    Science.gov (United States)

    Zhong, Shaobo; Lan, Guiwen; Zhu, Haiguo; Wen, Renqiang; Zhao, Qiansheng; Huang, Quanyi

    2008-12-01

    Because of their inherent advantages, Geographic Information System (GIS) and Remote Sensing (RS) are extremely useful for dealing with geographically referenced information. In the study of epidemics, most data are geographically referenced, which makes GIS and RS the perfect even necessary tools for processing, analysis, representation of epidemic data. Comprehensively considering the data requirements in the study of highly pathogenic avian influenza (HPAI) coupled with the quality of the existing remotely sensed data in terms of the resolution of space, time and spectra, the data sensed by MODIS are chosen and the relevant methods and procedures of data processing from RS and GIS for some environmental factors are proposed. Through using spatial analysis functions and Exploratory Spatial Data Analysis (ESDA) of GIS, some results of relationship between HPAI occurrences and these potential factors are presented. The role played by bird migration is also preliminarily illustrated with some operations such as visualization, overlapping etc. provided by GIS. Through the work of this paper, we conclude: Firstly, the migration of birds causes the spread of HPAI all over the country in 2004-2005. Secondly, the migration of birds is the reason why the spread of HPAI is perturbed. That is, for some classic communicable diseases, their spread exhibits obvious spatial diffusion process. However, the spread of HPAI breaks this general rule. We think leap diffusion and time lag are the probable reasons for this kind of phenomena. Potential distribution of HPAI viruses (corresponding to the distribution of flyways and putative risk sources) is not completely consistent with the occurrences of HPAI. For this phenomenon, we think, in addition to the flyways of birds, all kinds of geographical, climatic factors also have important effect on the occurrences of HPAI. Through the case study of HPAI, we can see that GIS and RS can play very important roles in the study of epidemics.

  8. Peramivir injection in the treatment of acute influenza: a review of the literature

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    Wester A; Shetty AK

    2016-01-01

    Ashley Wester,1 Avinash K Shetty2 1Department of Pharmacy, 2Department of Pediatrics, Wake Forest School of Medicine, Winston-Salem, NC, USA Abstract: Influenza virus infection is a major cause of morbidity and mortality in children and adults globally. Seasonal epidemics are common due to the rapid virus evolution, whereas the frequent emergence of antigenic variants can result in pandemics and sporadic/endemic avian influenza virus infections. Although annual vaccination is the mainstay for...

  9. No serological evidence that harbour porpoises are additional hosts of influenza B viruses.

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    Rogier Bodewes

    Full Text Available Influenza A and B viruses circulate among humans causing epidemics almost annually. While various hosts for influenza A viruses exist, influenza B viruses have been detected only in humans and seals. However, recurrent infections of seals in Dutch coastal waters with influenza B viruses that are antigenetically distinct from influenza B viruses circulating among humans suggest that influenza B viruses have been introduced into this seal population by another, non-human, host. Harbour porpoises (Phocoena phocoena are sympatric with seals in these waters and are also occasionally in close contact with humans after stranding and subsequent rehabilitation. In addition, virus attachment studies demonstrated that influenza B viruses can bind to cells of the respiratory tract of these animals. Therefore, we hypothesized that harbour porpoises might be a reservoir of influenza B viruses. In the present study, an unique set of serum samples from 79 harbour porpoises, stranded alive on the Dutch coast between 2003 and 2013, was tested for the presence of antibodies against influenza B viruses by use of the hemagglutination inhibition test and for antibodies against influenza A viruses by use of a competitive influenza A nucleoprotein ELISA. No antibodies were detected against either virus, suggesting that influenza A and B virus infections of harbour porpoises in Dutch coastal waters are not common, which was supported by statistical analysis of the dataset.

  10. Harmonizing influenza primary-care surveillance in the United Kingdom: piloting two methods to assess the timing and intensity of the seasonal epidemic across several general practice-based surveillance schemes.

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    Green, H K; Charlett, A; Moran-Gilad, J; Fleming, D; Durnall, H; Thomas, D Rh; Cottrell, S; Smyth, B; Kearns, C; Reynolds, A J; Smith, G E; Elliot, A J; Ellis, J; Zambon, M; Watson, J M; McMenamin, J; Pebody, R G

    2015-01-01

    General Practitioner consultation rates for influenza-like illness (ILI) are monitored through several geographically distinct schemes in the UK, providing early warning to government and health services of community circulation and intensity of activity each winter. Following on from the 2009 pandemic, there has been a harmonization initiative to allow comparison across the distinct existing surveillance schemes each season. The moving epidemic method (MEM), proposed by the European Centre for Disease Prevention and Control for standardizing reporting of ILI rates, was piloted in 2011/12 and 2012/13 along with the previously proposed UK method of empirical percentiles. The MEM resulted in thresholds that were lower than traditional thresholds but more appropriate as indicators of the start of influenza virus circulation. The intensity of the influenza season assessed with the MEM was similar to that reported through the percentile approach. The MEM pre-epidemic threshold has now been adopted for reporting by each country of the UK. Further work will continue to assess intensity of activity and apply standardized methods to other influenza-related data sources.

  11. Passive immune neutralization strategies for prevention and control of influenza A infections.

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    Ye, Jianqiang; Shao, Hongxia; Perez, Daniel R

    2012-02-01

    Although vaccination significantly reduces influenza severity, seasonal human influenza epidemics still cause more than 250,000 deaths annually. Vaccine efficacy is limited in high-risk populations such as infants, the elderly and immunosuppressed individuals. In the event of an influenza pandemic (such as the 2009 H1N1 pandemic), a significant delay in vaccine availability represents a significant public health concern, particularly in high-risk groups. The increasing emergence of strains resistant to the two major anti-influenza drugs, adamantanes and neuraminidase inhibitors, and the continuous circulation of avian influenza viruses with pandemic potential in poultry, strongly calls for alternative prophylactic and treatment options. In this review, we focus on passive virus neutralization strategies for the prevention and control of influenza type A viruses.

  12. Victoria Brú Sánchez and the epidemic of influenza in Cienfuegos, 1918 Victoria Brú Sánchez y la epidemia de Influenza de 1918 en Cienfuegos.

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    Alfredo Dario Espinosa Brito

    2011-04-01

    Full Text Available Brief biographical data are exposed about the nurse Victoria Brú Sánchez, such as her birth, childhood and adolescent years. Some factors are mentioned that influenced in their vocational orientation toward the Infirmary, such as her family antecedents and personal experiences when witnessing other epidemics that whipped our population in those years. We refer too her life as student of the School of Nurses in the Hospital Nuestra Señora de las Mercedes de La Habana. It is mentioned as well all the places where she worked after graduation and the different positions that she occupied during its brief, but brilliant, professional life. The most characteristic features in her personality and her self-denying and heroic behavior, are analyzed, principally during the epidemic of Influenza that affected Cienfuegos in the year 1918, moment in which she lost the life trying to help other people.Se exponen breves datos biográficos de la enfermera Victoria Brú Sánchez, en cuanto a su nacimiento, infancia y juventud. Se mencionan algunos factores que influyeron en su orientación vocacional hacia la enfermería, tales como sus antecedentes familiares y vivencias personales al presenciar otras epidemias que azotaban a nuestra población en aquellos años. Se describe suscintamente su etapa de alumna de la Escuela de Enfermeras del Hospital Nuestra Señora de las Mercedes de La Habana y, una vez graduada, se mencionan todos los lugares donde trabajó y los distintos cargos que ocupó durante su breve, pero brillante, vida profesional. Se analizan los rasgos más característicos de su personalidad y su comportamiento abnegado y heroico durante la epidemia de Influenza que afectó a Cienfuegos en el año 1918, donde perdió la vida en el cumplimiento de su deber y por lo cual se convirtió en mártir de la enfermería cubana.

  13. 江阴市2009年甲型H1N1流感疫情分析%Epidemic features and influential factors of influenza A(H1N1)in Jiangyin in 2009

    Institute of Scientific and Technical Information of China (English)

    马焰

    2011-01-01

    目的 探讨江阴市甲型H1N1流感流行特征并提出防治措施.方法 对江阴市2009年甲型H1N1流感疫情资料进行分析.结果 2009年累计确诊甲型H1N1流感病人22例,其中重症病例3例、危重2例、死亡1例,发病率为1.25/10万.发生2起暴发疫情,均发生在学校.检测流感样病人咽拭子标本124份,甲型H1N1流感核酸阳性率为11.29%.结论江阴市采取的一系列甲型H1N1流感防控措施整体上显著有效,2009年江阴市甲型H1N1流感疫情处于低流行水平.%Aim To survey the epidemic features of influenza A (H1N1 ) in Jiang yin City. Methods Epidemic data of influenza A(H1N1 ) in Jiangyin of Jiangsu Province in 2009 were analyzed. Results In 2009, a total of 22 influenza A (H1N1) cases were confirmed,among them there were 5 severe cases,1 deaths.The morbidity rate was 1.25/100000 population. There were 2 outbreaks all in schools. 124 nasopharyngeal swab samples of Influenza-like patients were tested.The positive rate of nucleic acid influenza A (H1N1) was 11.29%. Conclusion The control measuers in combot against influenza A(H1N1 ) in Jiangyin is effective and the epidemic of influenza A(H1N1 ) in Jiangyin is at a low level n 2009.

  14. Live attenuated intranasal influenza vaccine.

    Science.gov (United States)

    Esposito, Susanna; Montinaro, Valentina; Groppali, Elena; Tenconi, Rossana; Semino, Margherita; Principi, Nicola

    2012-01-01

    Annual vaccination is the most effective means of preventing and controlling influenza epidemics, and the traditional trivalent inactivated vaccine (TIV) is by far the most widely used. Unfortunately, it has a number of limitations, the most important of which is its poor immunogenicity in younger children and the elderly, the populations at greatest risk of severe influenza. Live attenuated influenza vaccine (LAIV) has characteristics that can overcome some of these limitations. It does not have to be injected because it is administered intranasally. It is very effective in children and adolescents, among whom it prevents significantly more cases of influenza than the traditional TIV. However, its efficacy in adults has not been adequately documented, which is why it has not been licensed for use by adults by the European health authorities. LAIV is safe and well tolerated by children aged > 2 y and adults, but some concerns arisen regarding its safety in younger children and subjects with previous asthma or with recurrent wheezing. Further studies are needed to solve these problems and to evaluate the possible role of LAIV in the annual vaccination of the general population.

  15. Latitudinal variations in seasonal activity of influenza and respiratory syncytial virus (RSV: a global comparative review.

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    Kimberly Bloom-Feshbach

    Full Text Available There is limited information on influenza and respiratory syncytial virus (RSV seasonal patterns in tropical areas, although there is renewed interest in understanding the seasonal drivers of respiratory viruses.We review geographic variations in seasonality of laboratory-confirmed influenza and RSV epidemics in 137 global locations based on literature review and electronic sources. We assessed peak timing and epidemic duration and explored their association with geography and study settings. We fitted time series model to weekly national data available from the WHO influenza surveillance system (FluNet to further characterize seasonal parameters.Influenza and RSV activity consistently peaked during winter months in temperate locales, while there was greater diversity in the tropics. Several temperate locations experienced semi-annual influenza activity with peaks occurring in winter and summer. Semi-annual activity was relatively common in tropical areas of Southeast Asia for both viruses. Biennial cycles of RSV activity were identified in Northern Europe. Both viruses exhibited weak latitudinal gradients in the timing of epidemics by hemisphere, with peak timing occurring later in the calendar year with increasing latitude (P<0.03. Time series model applied to influenza data from 85 countries confirmed the presence of latitudinal gradients in timing, duration, seasonal amplitude, and between-year variability of epidemics. Overall, 80% of tropical locations experienced distinct RSV seasons lasting 6 months or less, while the percentage was 50% for influenza.Our review combining literature and electronic data sources suggests that a large fraction of tropical locations experience focused seasons of respiratory virus activity in individual years. Information on seasonal patterns remains limited in large undersampled regions, included Africa and Central America. Future studies should attempt to link the observed latitudinal gradients in

  16. Universal immunity to influenza must outwit immune evasion

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    Sergio Manuel Quinones-Parra

    2014-06-01

    Full Text Available Although an influenza vaccine has been available for 70 years, influenza virus still causes seasonal epidemics and worldwide pandemics. Currently available vaccines elicit strain-specific antibody responses to the surface haemagglutinin (HA and neuraminidase (NA proteins, but these can be ineffective against serologically-distinct viral variants and novel subtypes. Thus, there is a need for cross-protective or universal influenza vaccines to overcome the necessity for annual immunisation against seasonal influenza and to provide immunity to reduce the severity of infection with pandemic or outbreak viruses. It is well established that natural influenza infection can provide cross-reactive immunity that can reduce the impact of infection with distinct influenza type A strains and subtypes, including H1N1, H3N2, H2N2, H5N1 and H7N9. The key to generating universal influenza immunity via vaccination is to target functionally-conserved regions of the virus, which include epitopes on the internal proteins for cross-reactive T cell immunity or on the HA stem for broadly reactive antibody responses. In the wake of the 2009 H1N1 pandemic, broadly neutralizing antibodies have been characterized and isolated from convalescent and vaccinated individuals, inspiring development of new vaccination techniques to elicit such responses. Induction of influenza-specific T cell responses through vaccination has also been examined in clinical trials. Strong evidence is available from human and animal models of influenza to show that established influenza-specific T cell memory can reduce viral shedding and symptom severity. However, the published evidence also shows that CD8+ T cells can efficiently select immune escape mutants early after influenza virus infection. Here, we discuss universal immunity to influenza viruses mediated by both cross-reactive T cells and antibodies, the mechanisms of immune evasion in influenza, and how to counteract commonly occurring

  17. Synchrony of clinical and laboratory surveillance for influenza in Hong Kong.

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    Lin Yang

    Full Text Available BACKGROUND: Consultation rates of influenza-like illness (ILI in an outpatient setting have been regarded as a good indicator of influenza virus activity in the community. As ILI-like symptoms may be caused by etiologies other than influenza, and influenza virus activity in the tropics and subtropics is less predictable than in temperate regions, the correlation between of ILI and influenza virus activity in tropical and subtropical regions is less well defined. METHODOLOGY AND PRINCIPAL FINDINGS: In this study, we used wavelet analysis to investigate the relationship between seasonality of influenza virus activity and consultation rates of ILI reported separately by General Out-patient Clinics (GOPC and General Practitioners (GP. During the periods 1998-2000 and 2002-2003, influenza virus activity exhibited both annual and semiannual cycles, with one peak in the winter and another in late spring or early summer. But during 2001 and 2004-2006, only annual cycles could be clearly identified. ILI consultation rates in both GOPC and GP settings share a similar non-stationary seasonal pattern. We found high coherence between ILI in GOPC and influenza virus activity for the annual cycle, but this was only significant (p<0.05 during the periods 1998-1999 and 2002-2006. For the semiannual cycle high coherence (p<0.05 was also found significant during the period 1998-1999 and year 2003 when two peaks of influenza were evident. Similarly, ILI in GP setting is also associated with influenza virus activity for both the annual and semiannual cycles. On average, oscillation of ILI in GP and of ILI in GOPC preceded influenza virus isolation by approximately four and two weeks, respectively. CONCLUSIONS: Our findings suggest that consultation rates of ILI precede the oscillations of laboratory surveillance by at least two weeks and can be used as a predictor for influenza epidemics in Hong Kong. The validity of our model for other tropical regions needs to be

  18. Impact of information on intentions to vaccinate in a potential epidemic: Swine-origin Influenza A (H1N1).

    Science.gov (United States)

    Chanel, Olivier; Luchini, Stéphane; Massoni, Sébastien; Vergnaud, Jean-Christophe

    2011-01-01

    Vaccination campaigns to prevent the spread of epidemics are successful only if the targeted populations subscribe to the recommendations of health authorities. However, because compulsory vaccination is hardly conceivable in modern democracies, governments need to convince their populations through efficient and persuasive information campaigns. In the context of the swine-origin A (H1N1) 2009 pandemic, we use an interactive study among the general public in the South of France, with 175 participants, to explore what type of information can induce change in vaccination intentions at both aggregate and individual levels. We find that individual attitudes to vaccination are based on rational appraisal of the situation, and that it is information of a purely scientific nature that has the only significant positive effect on intention to vaccinate.

  19. Flutracking weekly online community survey of influenza-like illness annual report, 2015.

    Science.gov (United States)

    Dalton, Craig B; Carlson, Sandra J; Durrheim, David N; Butler, Michelle T; Cheng, Allen C; Kelly, Heath A

    2016-12-24

    Flutracking is a national online community influenza-like illness (ILI) surveillance system that monitors weekly ILI activity and impact in the Australian community. This article reports on the 2015 findings from Flutracking. From 2014 to 2015 there was a 38.5% increase in participants to 27,824 completing at least 1 survey with a peak weekly response of 25,071 participants. The 2015 Flutracking national ILI weekly fever and cough percentages peaked in late August at 5.0% in the unvaccinated group, in the same week as the national counts of laboratory confirmed influenza peaked. A similar percentage of Flutracking participants took two or more days off from work or normal duties in 2015 (peak level 2.3%) compared with 2014 (peak level 2.5%) and the peak weekly percentage of participants seeking health advice was 1.6% in both 2014 and 2015. Flutracking fever and cough peaked in the same week as Influenza Complications Alert Network surveillance system influenza hospital admissions. The percentage of Flutracking participants aged 5 to 19 years with cough and fever in 2015 was the highest since 2011. The 2015 season was marked by a transition to predominantly influenza B strain circulation, which particularly affected younger age groups. However, for those aged 20 years and over, the 2015 national Flutracking influenza season was similar to 2014 in community ILI levels and impact.

  20. Using routine surveillance data to estimate the epidemic potential of emerging zoonoses: application to the emergence of US swine origin influenza A H3N2v virus.

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    Simon Cauchemez

    Full Text Available BACKGROUND: Prior to emergence in human populations, zoonoses such as SARS cause occasional infections in human populations exposed to reservoir species. The risk of widespread epidemics in humans can be assessed by monitoring the reproduction number R (average number of persons infected by a human case. However, until now, estimating R required detailed outbreak investigations of human clusters, for which resources and expertise are not always available. Additionally, existing methods do not correct for important selection and under-ascertainment biases. Here, we present simple estimation methods that overcome many of these limitations. METHODS AND FINDINGS: Our approach is based on a parsimonious mathematical model of disease transmission and only requires data collected through routine surveillance and standard case investigations. We apply it to assess the transmissibility of swine-origin influenza A H3N2v-M virus in the US, Nipah virus in Malaysia and Bangladesh, and also present a non-zoonotic example (cholera in the Dominican Republic. Estimation is based on two simple summary statistics, the proportion infected by the natural reservoir among detected cases (G and among the subset of the first detected cases in each cluster (F. If detection of a case does not affect detection of other cases from the same cluster, we find that R can be estimated by 1-G; otherwise R can be estimated by 1-F when the case detection rate is low. In more general cases, bounds on R can still be derived. CONCLUSIONS: We have developed a simple approach with limited data requirements that enables robust assessment of the risks posed by emerging zoonoses. We illustrate this by deriving transmissibility estimates for the H3N2v-M virus, an important step in evaluating the possible pandemic threat posed by this virus. Please see later in the article for the Editors' Summary.

  1. [Epidemic of influenza A(H1N1) 2009 in the French overseas territories of the Americas: epidemiological surveillance set up and main results, April 2009-January 2010].

    Science.gov (United States)

    Larrieu, S; Rosine, J; Ledrans, M; Flamand, C; Chappert, J-L; Cassadou, S; Carvalho, L; Blateau, A; Barrau, M; Ardillon, V; Quénel, P

    2011-05-01

    Guadeloupe, French Guiana, Martinique, St. Martin and St. Barthelemy were the French territories most exposed to the new influenza A(H1N1)v, and adequate epidemiological surveillance tools were promptly developed in order to detect its emergence. The first stage, "containment phase", consisted in detection and management of individual cases. Then, when an autochthonous A(H1N1)v circulation was confirmed, its evolution has been monitored within the whole population, mainly through data collected from sentinel doctors' networks and virological surveillance. This allowed to detect very early the occurrence of epidemics, and to follow their evolution until they were over. Like all the other Caribbean countries, the five French overseas territories were hit by an outbreak of influenza A(H1N1)v. Although they had globally similar characteristics, each epidemic had its specificity in terms of scale and severity. They started between August and September 2009 in four of the five territories, while the last one, St. Barthelemy, was not affected until the end of the year. Attack rate estimates varied from 28 to 70 per 1000 inhabitants according to the territory, and hospitalisation rate varied from 4.3 to 10.3 per 1000 cases. Severity rate didn't reach 1 per 1000 cases in any of the territories. Compared to metropolitan France, the surveillance system presented several strengths, including the pre-existence of both an active sentinel network and an expert committee on emerging diseases in each territory. On the other hand, specific difficulties appeared, notably linked with logistical aspects of virological surveillance and the co-circulation of dengue virus in Guadeloupe and St. Barthelemy. Despite these difficulties, the different tools allowed early detection of the epidemics and follow-up of their evolution. All of them lead to very concordant results, suggesting that they are completely appropriate to monitor a potential new epidemic wave.

  2. What's public? What's private? Policy trade-offs and the debate over mandatory annual influenza vaccination for health care workers.

    Science.gov (United States)

    Mah, Catherine L

    2008-01-01

    Policy decisions about public health services differ from those for personal health services. Both require trade-offs between such policy goals as liberty, security, efficiency, and equity. In public health, however, decisions about who will approve, pay for, and deliver services are often accompanied by decisions on when and how to compel individual behaviour. Policy becomes complex because different stakeholders interpret evidence differently: stakeholders may assign different weights to policy goals and may even define the same goals differently. In the debate over mandatory annual influenza vaccination for health care workers, for example, proponents as well as opponents of mandatory vaccination may convey arguments in security terms. Those in favour of mandatory vaccination emphasize subclinical infections and duty of care (public security) while those opposed emphasize risk of adverse events (personal security). Proponents assert less worker absenteeism (efficiency) while opponents stress coercion and alternate personal infection control measures (liberty and individual rights/responsibilities). Consequently, stakeholders talk past each other. Determining the place of mandatory influenza vaccination for health care workers thus demands reconciling policy trade-offs and clarifying the underlying disputes hidden in the language of the policy debate.

  3. The dynamics of avian influenza in western Arctic snow geese: implications for annual and migratory infection patterns

    Science.gov (United States)

    Samuel, Michael D.; Hall, Jeffrey S.; Brown, Justin D.; Goldberg, Diana R.; Ip, Hon S.; Baranyuk, Vasily V.

    2015-01-01

    Wild water birds are the natural reservoir for low-pathogenic avian influenza viruses (AIV). However, our ability to investigate the epizootiology of AIV in these migratory populations is challenging, and despite intensive worldwide surveillance, remains poorly understood. We conducted a cross-sectional, retrospective analysis in Pacific Flyway lesser snow geese Chen caerulescens to investigate AIV serology and infection patterns. We collected nearly 3,000 sera samples from snow geese at 2 breeding colonies in Russia and Canada during 1993-1996 and swab samples from > 4,000 birds at wintering and migration areas in the United States during 2006-2011. We found seroprevalence and annual seroconversion varied considerably among years. Seroconversion and infection rates also differed between snow goose breeding colonies and wintering areas, suggesting that AIV exposure in this gregarious waterfowl species is likely occurring during several phases (migration, wintering and potentially breeding areas) of the annual cycle. We estimated AIV antibody persistence was longer (14 months) in female geese compared to males (6 months). This relatively long period of AIV antibody persistence suggests that subtype-specific serology may be an effective tool for detection of exposure to subtypes associated with highly-pathogenic AIV. Our study provides further evidence of high seroprevalence in Arctic goose populations, and estimates of annual AIV seroconversion and antibody persistence for North American waterfowl. We suggest future AIV studies include serology to help elucidate the epizootiological dynamics of AIV in wild bird populations.

  4. Recurrent dynamics in an epidemic model due to stimulated bifurcation crossovers

    Energy Technology Data Exchange (ETDEWEB)

    Juanico, Drandreb Earl [Department of Mathematics, Ateneo de Manila University, Loyola Heights, Quezon City, Philippines 1108 (Philippines); National Institute of Physics, University of the Philippines, Diliman, Quezon City, Philippines 1101 (Philippines)

    2015-05-15

    Epidemics are known to persist in the form of recurrence cycles. Despite intervention efforts through vaccination and targeted social distancing, peaks of activity for infectious diseases like influenza reappear over time. Analysis of a stochastic model is here undertaken to explore a proposed cycle-generating mechanism – the bifurcation crossover. Time series from simulations of the model exhibit oscillations similar to the temporal signature of influenza activity. Power-spectral density indicates a resonant frequency, which corresponds to the annual seasonality of influenza in temperate zones. The study finds that intervention actions influence the extinguishability of epidemic activity. Asymptotic solution to a backward Kolmogorov equation corresponds to a mean extinction time that is a function of both intervention efficacy and population size. Intervention efficacy must be greater than a certain threshold to increase the chances of extinguishing the epidemic. Agreement of the model with several phenomenological features of epidemic cycles lends to it a tractability that may serve as early warning of imminent outbreaks.

  5. Air pollutants and health outcomes: Assessment of confounding by influenza

    Science.gov (United States)

    Thach, Thuan-Quoc; Wong, Chit-Ming; Chan, King-Pan; Chau, Yuen-Kwan; Neil Thomas, G.; Ou, Chun-Quan; Yang, Lin; Peiris, Joseph S. M.; Lam, Tai-Hing; Hedley, Anthony J.

    2010-04-01

    We assessed confounding of associations between short-term effects of air pollution and health outcomes by influenza using Hong Kong mortality and hospitalization data for 1996-2002. Three measures of influenza were defined: (i) intensity: weekly proportion of positive influenza viruses, (ii) epidemic: weekly number of positive influenza viruses ≥4% of the annual number for ≥2 consecutive weeks, and (iii) predominance: an epidemic period with co-circulation of respiratory syncytial virus influenza on associations between nitrogen dioxide (NO 2), sulfur dioxide (SO 2), particulate matter with aerodynamic diameter ≤10 μm (PM 10) and ozone (O 3) and health outcomes including all natural causes mortality, cardiorespiratory mortality and hospitalization. Generalized additive Poisson regression model with natural cubic splines was fitted to control for time-varying covariates to estimate air pollution health effects. Confounding with influenza was assessed using an absolute difference of >0.1% between unadjusted and adjusted excess risks (ER%). Without adjustment, pollutants were associated with positive ER% for all health outcomes except asthma and stroke hospitalization with SO 2 and stroke hospitalization with O 3. Following adjustment, changes in ER% for all pollutants were 0.1% for mortality from stroke with NO 2 and SO 2, cardiac or heart disease with NO 2, PM 10 and O 3, lower respiratory infections with NO 2 and O 3 and mortality from chronic obstructive pulmonary disease with all pollutants. Changes >0.1% were seen for acute respiratory disease hospitalization with NO 2, SO 2 and O 3 and acute lower respiratory infections hospitalization with PM 10. Generally, influenza does not confound the observed associations of air pollutants with all natural causes mortality and cardiovascular hospitalization, but for some pollutants and subgroups of cardiorespiratory mortality and respiratory hospitalization there was evidence to suggest confounding by influenza.

  6. Heterosybtypic T-cell immunity to influenza in humans: challenges for universal T-cell influenza vaccines

    Directory of Open Access Journals (Sweden)

    Saranya eSridhar

    2016-05-01

    Full Text Available Influenza A virus (IAV remains a significant global health issue causing annual epidemics, pandemics and sporadic human infections with highly pathogenic avian or swine influenza viruses. Current inactivated and live vaccines are the mainstay of the public health response to influenza although vaccine efficacy is lower against antigenically distinct viral strains. The first pandemic of the 21st century underlined the urgent need to develop new vaccines capable of protection against a broad range of influenza strains. Such universal influenza vaccines are based on the idea of heterosubtypic immunity wherein immune responses to epitopes conserved across IAV strains can confer protection against subsequent infection and disease. T-cells recognising conserved antigens are a key contributor to reducing viral load and limiting disease severity during heterosubtypic infection in animal models. Recent studies undertaken during the 2009 H1N1 pandemic provided key insights into the role of cross-reactive T-cells in mediating heterosubtypic protection in humans. This review focuses on human influenza to discuss the epidemiological observations that underpin cross-protective immunity, the role of T-cells as key players in mediating heterosubtypic immunity including recent data from natural history cohort studies and the ongoing clinical development of T-cell inducing universal influenza vaccines. The challenges and knowledge gaps for developing vaccines to generate long-lived protective T-cell responses is discussed.

  7. Waves of El Nino-southern Oscillation and Influenza Pandemics

    Directory of Open Access Journals (Sweden)

    Olusegun Steven Ayodele Oluwole

    2016-04-01

    Full Text Available Influenza pandemics have occurred at irregular intervals for over 500 years, unlike seasonal influenza epidemics which occur annually. Although the risk factors are known, the basis for the timing of influenza pandemic waves are unknown. Coherence of peaks of El Niño and influenza pandemic in 2009–2010, however, suggests that both waves are coupled. This study was done to determine the relation of influenza pandemics to the peaks and waveforms of El Niño southern oscillation (ENSO. ENSO cycles from 1871–2015 which had El Niño phases were windowed from Multivariate El Niño Index. Influenza pandemic peaks were mapped to ENSO monthly time series. ENSO waveforms were compared graphically, and fitted to nonstationary cosinor models. Second order polynomial regression model was fitted to the peak and duration of El Niño. Agglomerative hierarchical cluster of ENSO waveforms was performed. All influenza pandemic peaks mapped to El Niño peaks, with lags of 0–5 months. ENSO waveforms during influenza pandemics share parameters of oscillation. Nonstationary cosinor models showed that ENSO cycles are complex waves. There was second order polynomial relationship between peak and duration of El Niños, p < 0.0001. ENSO waveforms clustered into four distinct groups. ENSO waveforms during influenza pandemics of 1889–1900, 1957–1958, and 1968–1969 linked closely. ENSO indices were significantly high from 7–16 months after onset of cycles, p < 0.0001. Surveillance for El Niño events to forecast periods of maximal transmission and survival of influenza A viruses is, therefore, crucial for public health control strategies.

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

    NARCIS (Netherlands)

    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

    2012-01-01

    Background and objectives 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. Patients/methods This study was conducted during the pandemic influenza

  9. Clinical Implications of Antiviral Resistance in Influenza

    Directory of Open Access Journals (Sweden)

    Timothy C. M. Li

    2015-09-01

    Full Text Available Influenza is a major cause of severe respiratory infections leading to excessive hospitalizations and deaths globally; annual epidemics, pandemics, and sporadic/endemic avian virus infections occur as a result of rapid, continuous evolution of influenza viruses. Emergence of antiviral resistance is of great clinical and public health concern. Currently available antiviral treatments include four neuraminidase inhibitors (oseltamivir, zanamivir, peramivir, laninamivir, M2-inibitors (amantadine, rimantadine, and a polymerase inhibitor (favipiravir. In this review, we focus on resistance issues related to the use of neuraminidase inhibitors (NAIs. Data on primary resistance, as well as secondary resistance related to NAI exposure will be presented. Their clinical implications, detection, and novel therapeutic options undergoing clinical trials are discussed.

  10. Clinical Implications of Antiviral Resistance in Influenza.

    Science.gov (United States)

    Li, Timothy C M; Chan, Martin C W; Lee, Nelson

    2015-09-14

    Influenza is a major cause of severe respiratory infections leading to excessive hospitalizations and deaths globally; annual epidemics, pandemics, and sporadic/endemic avian virus infections occur as a result of rapid, continuous evolution of influenza viruses. Emergence of antiviral resistance is of great clinical and public health concern. Currently available antiviral treatments include four neuraminidase inhibitors (oseltamivir, zanamivir, peramivir, laninamivir), M2-inibitors (amantadine, rimantadine), and a polymerase inhibitor (favipiravir). In this review, we focus on resistance issues related to the use of neuraminidase inhibitors (NAIs). Data on primary resistance, as well as secondary resistance related to NAI exposure will be presented. Their clinical implications, detection, and novel therapeutic options undergoing clinical trials are discussed.

  11. A SEASONAL INFLUENZA THEORY AND MATHEMATICAL MODEL INCORPORATING METEOROLOGICAL AND SOCIO- BEHAVIORAL FACTORS

    Institute of Scientific and Technical Information of China (English)

    Zhixiang ZHOU

    2009-01-01

    On the basis of a comprehensive literature review and data analysis of global influenza surveillance,a transmission theory based numerical model is developed to understand the causative factors of influenza seasonality and the biodynamical mechanisms of seasonal flu. The model is applied to simulate the seasonality and weekly activity of influenza in different areas across all continents and climate zones around the world. Model solution and the good matches between model output and actual influenza indexes affirm that influenza activity is highly auto-correlative and relies on determinants of a broad spectrum. Internal dynamic resonance; variations of meteorological elements (solar radiation,precipitation and dewpoint); socio-behavioral influences and herd immunity to circulating strains prove to be the critical explanatory thctors of the seasonality and weekly activity of influenza. In all climate regions,influenza activity is proportional to the exponential of the number of days with precipitation and to the negative exponential of quarter power of sunny hours. Influenza activity is a negative exponential function of dewpoint in temperate and arctic regions and an exponential function of the absolute deviation of dewpoint from its annual mean in the tropics. Epidemics of seasonal influenza could be deemed as the consequence of the dynamic resonance and interactions of determinants. Early interventions (such as opportune vaccination,prompt social distancing,and maintaining incidence well below a baseline) are key to the control and prevention of seasonal influenza. Moderate amount of sunlight exposure or Vitamin D supplementation during rainy and short-day photoperiod seasons,more outdoor activities,and appropriate indoor dewpoint deserve great attention in influenza prevention. To a considerable degree,the study reveals the mechanism of inlluenza seasonality,demonstrating a potential for influenza activity projection. The concept and algorithm can be explored

  12. Knowledge of and attitudes to influenza in unvaccinated primary care physicians and nurses.

    Science.gov (United States)

    Domínguez, Angela; Godoy, Pere; Castilla, Jesús; María Mayoral, José; Soldevila, Núria; Torner, Núria; Toledo, Diana; Astray, Jenaro; Tamames, Sonia; García-Gutiérrez, Susana; González-Candelas, Fernando; Martín, Vicente; Díaz, José

    2014-01-01

    Primary healthcare workers, especially nurses, are exposed to the vast majority of patients with influenza and play an important role in vaccinating patients. Healthcare workers' misconceptions about influenza and influenza vaccination have been reported as possible factors associated with lack of vaccination. The objective of this study was to compare the characteristics of unvaccinated physicians and unvaccinated nurses in the 2011-2012 influenza season. We performed an anonymous web survey of Spanish primary healthcare workers in 2012. Information was collected on vaccination and knowledge of and attitudes to the influenza vaccine. Multivariate analysis was performed using unconditional logistic regression. We included 461 unvaccinated physicians and 402 unvaccinated nurses. Compared with unvaccinated nurses, unvaccinated physicians had more frequently received seasonal influenza vaccination in the preceding seasons (aOR 1.58; 95% CI 1.11-2.25), and more frequently believed that vaccination of high risk individuals is effective in reducing complications (aOR 2.53; 95% CI 1.30-4.95) and that influenza can be a serious illness (aOR 1.65; 95% CI 1.17-2.32). In contrast, unvaccinated physicians were less concerned about infecting patients (aOR 0.62; 95% CI 0.40-0.96). Unvaccinated nurses had more misconceptions than physicians about influenza and the influenza vaccine and more doubts about the severity of annual influenza epidemics in patients with high risk conditions and the prevention of complications by means of the influenza vaccination. For unvaccinated physicians, strategies to improve vaccination coverage should stress the importance of physicians as a possible source of infection of their patients. The effectiveness of influenza vaccination of high risk persons should be emphasized in nurses.

  13. Why were Turks unwilling to accept the A/H1N1 influenza-pandemic vaccination? People's beliefs and perceptions about the swine flu outbreak and vaccine in the later stage of the epidemic.

    Science.gov (United States)

    Gaygısız, Ümmügülsüm; Gaygısız, Esma; Özkan, Türker; Lajunen, Timo

    2010-12-16

    This study investigated the acceptability of the A/H1N1 influenza vaccination and related factors among 1137 adults in the later stage of the A/H1N1 outbreak in Turkey. Having already been vaccinated or intending to get vaccinated were related to trust in the vaccine effectiveness, perceived risk of the side effects, and benefits of getting vaccinated. Perceived long term consequences of the A/H1N1 infection, perceptions of the A/H1N1 information in media, and barriers for getting vaccinated were related to intention whereas anticipated epidemic situation in Turkey, being chronically ill, and being not married were related to having already been vaccinated.

  14. Influenza B virus-specific CD8

    NARCIS (Netherlands)

    C.E. van de Sandt (Carolien); Y. Dou (YingYing); S.E. Vogelzang-van Trierum (Stella ); K.B. Westgeest (Kim); M. Pronk (Mark); A.D.M.E. Osterhaus (Albert); R.A.M. Fouchier (Ron); G.F. Rimmelzwaan (Guus); M.L.B. Hillaire (Marine)

    2015-01-01

    textabstractInfluenza B viruses fall in two antigenically distinct lineages (B/Victoria/2/1987 and B/Yamagata/16/1988 lineage) that co-circulate with influenza A viruses of the H3N2 and H1N1 subtypes during seasonal epidemics. Infections with influenza B viruses contribute considerably to morbidity

  15. Analysis on the epidemic situation of human avian influenza and discussion on it's prevention and control strategy%人禽流感疫情分析及其防控策略探讨

    Institute of Scientific and Technical Information of China (English)

    黄文金; 宋诚本; 赖天然; 于勇; 肖琦磷; 胡江雯

    2011-01-01

    Objective To understand the epidemic situation and the epidemiological characteristics of human avian influenza in recent years, and to provide the scientific evidences for prevention and control the human avian influenza effectively. Methods Collected the information announcement material of human avian influenza on the World Health Organization and the Ministry of Public Health of China website since 2003 were collected, and its epidemiology characteristics were analyzed, the prevention and control strategies were discussed. Results The cumulative number of confirmed human cases of avian influenza A H5N1 reported to WHO were 516 cases since 2003 in the world, with the death cases of 306, the case fatality rate was 59.30%. and chinese cumulative number of confirmed human cases of avian influenza A/(H5Nl)were 40, including 26 death cases, the case fatality rate was 65.0%, was higher than the global average level. The human avian influenza had mostly happened in winter and spring. The children and the young adults had the mostly proportion in all the cases, the young adults' case fatality rate was high. There was no statistical significance between the male and female. Conclusion The case fatality rate of human avian influenza is high, the virus may be undergo variation and break through the inter-species barrier, it's ability of infection has strengthened. The risk of infection by people to people is increasing, The disease has a serious hazard to human. Should take the measures positively to prevent and control the human avian influenza effectively.%目的 了解近年来人禽流感疫情情况及其流行病学特征,为有效防控人禽流感提供科学依据.方法 收集2003年以来世界卫生组织、中国卫生部网站人感染高致病性禽流感疫情信息公布资料,分析其流行病学特征,探讨人禽流感防控策略.结果 全球自2003年以来累计报告人禽流感确诊病例516例,死亡306例,病死率为59.30%.其中,

  16. Needle-free influenza vaccination

    NARCIS (Netherlands)

    Amorij, Jean-Pierre; Hinrichs, Wouter L.J.; Frijlink, Henderik W.; Wilschut, Jan C.; Huckriede, Anke

    2010-01-01

    Vaccination is the cornerstone of influenza control in epidemic and pandemic situations. Influenza vaccines are typically given by intramuscular injection. However, needle-free vaccinations could offer several distinct advantages over intramuscular injections: they are pain-free, easier to distribut

  17. Quality improvement of medical and nursing service during "H7N9 bird influenza epidemic" in emergency department%“H7N9禽流感”流行期的急诊医护服务品质改进

    Institute of Scientific and Technical Information of China (English)

    王玲敏; 王芳; 刘川

    2013-01-01

    Objective To explore the quality improvement methods of medical and nursing service during "H7N9 bird influenza epidemic" in emergency department.Methods The methods included implementing "H7N9 bird influenza epidemic" prevention and control system,establishing "H7N9 bird influenza epidemic " prevention cycle,strengthening the management of nursing key links,strengthening the knowledge of "H7N9 bird influenza epidemic "and improving the medical service.Results There is to achieve zero cross infection of patients,zero infection of medical personnel during "H7N9 bird influenza epidemic" in emergency department.Conclusion Implemention the quality improvement methods of medical and nursing service during " H7N9 bird influenza epidemic" in emergency department can effectively prevent cross infection between hospital medical staffs and patients.%目的 探讨医院急诊科在预防“H7N9禽流感”中的一系列医护服务品质改进的有效措施.方法 通过落实“H7N9禽流感”防范管理制度,成立“H7N9禽流感”防范应急圈,加强护理重点环节管理,加强“H7N9禽流感”知识宣教和改进医疗服务形式等措施改进服务品质.结果 急诊科应对“H7N9禽流感”疫情期间,实现医院内患者零交叉感染,医护人员零感染.结论 “H7N9禽流感”流行期实施急诊医护服务品质改进,能有效防止院内医护患交叉感染.

  18. Performance of clinical signs in poultry for the detection of outbreaks during the avian influenza A (H7N7) epidemic in the Netherlands in 2003

    NARCIS (Netherlands)

    Elbers, A.R.W.; Koch, G.; Bouma, A.

    2005-01-01

    The aim of this study was to make an inventory of the clinical signs of high-pathogenicity avian influenza (HPAI), to facilitate the development of an operational syndrome-reporting system (SRS) in The Netherlands as an early warning system for HPAI outbreaks. A total of 537 poultry flocks (240 infe

  19. [Influenza surveillance in nine consecutive seasons, 2003-2012: results from National Influenza Reference Laboratory, Istanbul Faculty Of Medicine, Turkey].

    Science.gov (United States)

    Akçay Ciblak, Meral; Kanturvardar Tütenyurd, Melis; Asar, Serkan; Tulunoğlu, Merve; Fındıkçı, Nurcihan; Badur, Selim

    2012-10-01

    Influenza is a public health problem that affects 5-20% of the world population annually causing high morbidity and mortality especially in risk groups. In addition to determining prevention and treatment strategies with vaccines and antivirals, surveillance data plays an important role in combat against influenza. Surveillance provides valuable data on characteristics of influenza activity, on types, sub-types, antigenic properties and antiviral resistance profile of circulating viruses in a given region. The first influenza surveillance was initiated as a pilot study in 2003 by now named National Influenza Reference Laboratory, Istanbul Faculty of Medicine. Surveillance was launched at national level by Ministry of Health in 2004 and two National Influenza Laboratories, one in Istanbul and the other in Ankara, have been conducting surveillance in Turkey. Surveillance data obtained for nine consecutive years, 2003-2012, by National Influenza Reference Laboratory in Istanbul Faculty of Medicine have been summarized in this report. During 2003-2012 influenza surveillance seasons, a total of 11.077 nasal swabs collected in viral transport medium were sent to the National Influenza Reference Laboratory, Istanbul for analysis. Immun-capture ELISA followed by MDCK cell culture was used for detection of influenza viruses before 2009 and real-time RT-PCR was used thereafter. Antigenic characterizations were done by hemagglutination inhibition assay with the reactives supplied by World Health Organization. Analysis of the results showed that influenza B viruses have entered the circulation in 2005-2006 seasons, and have contributed to the epidemics at increasing rates every year except in the 2009 pandemic season. Influenza B Victoria and Yamagata lineages were cocirculating for two seasons. For other seasons either lineage was in circulation. Antigenic characterization revealed that circulating B viruses matched the vaccine composition either partially or totally for only

  20. Peramivir injection in the treatment of acute influenza: a review of the literature

    Directory of Open Access Journals (Sweden)

    Wester A

    2016-08-01

    Full Text Available Ashley Wester,1 Avinash K Shetty2 1Department of Pharmacy, 2Department of Pediatrics, Wake Forest School of Medicine, Winston-Salem, NC, USA Abstract: Influenza virus infection is a major cause of morbidity and mortality in children and adults globally. Seasonal epidemics are common due to the rapid virus evolution, whereas the frequent emergence of antigenic variants can result in pandemics and sporadic/endemic avian influenza virus infections. Although annual vaccination is the mainstay for influenza prevention and control, the use of antiviral agents must be considered for treatment and prophylaxis against influenza. Currently available antiviral drugs include neuraminidase inhibitors (NAIs, adamantanes, and a novel polymerase inhibitor (favipiravir. Peramivir is a recently US Food and Drug Administration-approved NAI for the treatment of acute uncomplicated influenza in adults. The chemical structure of peramivir allows it to bind to the influenza neuraminidase with much higher affinity than oseltamivir. Peramivir is effective against a variety of influenza A and B subtypes and has a lower half-maximal inhibitory concentration compared to other NAIs in in vitro studies. Peramivir can be administered intravenously, a route that is favorable for hospitalized, critically ill patients with influenza. The long half-life of peramivir allows for once-daily dosing. The drug is eliminated primarily by the kidneys, warranting dose adjustments in patients with renal dysfunction. Studies have assessed the clinical efficacy of peramivir for treatment of pandemic influenza A (H1N1. Although anecdotal evidence supports the use of peramivir in pediatric patients, pregnant women, and hospitalized patients with severe influenza receiving continuous renal replacement therapy and extracorporeal membrane oxygenation, well-designed, controlled clinical trials should be conducted in order to assess its clinical efficacy in these patient populations. Keywords

  1. Human mobility and epidemic invasion

    Science.gov (United States)

    Colizza, Vittoria

    2010-03-01

    The current H1N1 influenza pandemic is just the latest example of how human mobility helps drive infectious diseases. Travel has grown explosively in the last decades, contributing to an emerging complex pattern of traffic flows that unfolds at different scales, shaping the spread of epidemics. Restrictions on people's mobility are thus investigated to design possible containment measures. By considering a theoretical framework in terms of reaction-diffusion processes, it is possible to study the invasion dynamics of epidemics in a metapopulation system with heterogeneous mobility patterns. The system is found to exhibit a global invasion threshold that sets the critical mobility rate below which the epidemic is contained. The results provide a general framework for the understanding of the numerical evidence from detailed data-driven simulations that show the limited benefit provided by travel flows reduction in slowing down or containing an emerging epidemic.

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

    NARCIS (Netherlands)

    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

    2012-01-01

    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

  3. [Features of interepidemic influenza A and B viruses].

    Science.gov (United States)

    Litvinova, O M; Grinbaum, E B; Bannikov, A I; Konovalenko, I B; Konovalova, N I; Luzianina, T Ia; Kiselev, O I

    1995-01-01

    The comparison of interepidemic influenza viruses with the pathogens of resultant influenza epidemics has revealed that they belong to the same type (subtype) of influenza virus. A definite correlation has been found between the antigenic specificity of haemagglutinin of epidemic and interepidemic strains. The antigenic structure of the interepidemic viruses and the pathogens of further epidemics of influenza B viruses have been found to be completely identical. The interepidemic A(H1N1) isolates have been shown to be antigenic analogues of the causative agents of influenza A(H1N1) during the previous epidemics. Despite the time and place of their isolation, as well as the etiology of the previous and subsequent epidemics, the interepidemic influenza A(H3N2) viruses have been ascertained to be similar to the reference A/Bangkok/1/79.

  4. Characterization of regional influenza seasonality patterns in China and implications for vaccination strategies: spatio-temporal modeling of surveillance data.

    Directory of Open Access Journals (Sweden)

    Hongjie Yu

    2013-11-01

    Full Text Available BACKGROUND: The complexity of influenza seasonal patterns in the inter-tropical zone impedes the establishment of effective routine immunization programs. China is a climatologically and economically diverse country, which has yet to establish a national influenza vaccination program. Here we characterize the diversity of influenza seasonality in China and make recommendations to guide future vaccination programs. METHODS AND FINDINGS: We compiled weekly reports of laboratory-confirmed influenza A and B infections from sentinel hospitals in cities representing 30 Chinese provinces, 2005-2011, and data on population demographics, mobility patterns, socio-economic, and climate factors. We applied linear regression models with harmonic terms to estimate influenza seasonal characteristics, including the amplitude of annual and semi-annual periodicities, their ratio, and peak timing. Hierarchical Bayesian modeling and hierarchical clustering were used to identify predictors of influenza seasonal characteristics and define epidemiologically-relevant regions. The annual periodicity of influenza A epidemics increased with latitude (mean amplitude of annual cycle standardized by mean incidence, 140% [95% CI 128%-151%] in the north versus 37% [95% CI 27%-47%] in the south, p0.6 in provinces located within 27.4°N-31.3°N, slope of latitudinal gradient with latitude -0.016 [95% CI -0.025 to -0.008], p<0.001. In contrast, influenza B activity predominated in colder months throughout most of China. Climate factors were the strongest predictors of influenza seasonality, including minimum temperature, hours of sunshine, and maximum rainfall. Our main study limitations include a short surveillance period and sparse influenza sampling in some of the southern provinces. CONCLUSIONS: Regional-specific influenza vaccination strategies would be optimal in China; in particular, annual campaigns should be initiated 4-6 months apart in Northern and Southern China

  5. A Functional Role of Fibroblast Growth Factor Receptor 1 (FGFR1 in the Suppression of Influenza A Virus Replication.

    Directory of Open Access Journals (Sweden)

    Xin Liu

    Full Text Available Influenza A virus causes annual epidemics and occasional pandemics in humans. Here, we investigated four members of the fibroblast growth factor receptor (FGFR family; FGFR1 to 4, and examined their expression patterns in human lung epithelial cells A549 with influenza A virus infection. We identified a functional role of FGFR1 in influenza A/Puerto Rico/8/1934 (PR8 and A/Anhui/01/2005 (H5N1 virus replication. Our results showed that FGFR1 silencing by siRNA interference promoted influenza A/PR8 and H5N1 virus replication in A549 cells, while lentivirus-mediated exogenous FGFR1 expression significantly suppressed influenza A virus replication; however, FGFR4 did not have the same effects. Moreover, FGFR1 phosphorylation levels were downregulated in A549 cells by influenza A virus infection, while the repression of FGFR1 kinase using PD173074, a potent and selective FGFR1 inhibitor, could enhance virus replication. Furthermore, we found that FGFR1 inhibits influenza virus internalization, but not binding, during viral entry. These results suggested that FGFR1 specifically antagonizes influenza A virus replication, probably by blocking viral entry.

  6. ANALYSIS OF EPIDEMIC CHARACTERISTICS OF A (H1N1) INFLUENZA IN 2009 IN QINGHAI%青海省2009年甲型H1N1流感流行病学特征分析

    Institute of Scientific and Technical Information of China (English)

    曹海兰

    2012-01-01

    [目的]通过对青海省2009年甲型H1N1流感进行疫情资料的分析,为制定防治对策提供科学依据.[方法]运用描述流行病学方法描述甲型H1N1流感的流行病学特征,采用Excel软件进行统计分析.[结果]青海省2009年共报告甲型H1N1流感2109例,死亡7例,发病率为38.05/10万,死亡率为0.13/10万,病死率为0.33%:发病率居甲、乙类传染病第3位.病例主要集中在人口比较集中的西宁市和海东地区;发病高峰期在9~10月份,占全年甲型H1N1流感发病数的86.11%;发病年龄以8~24岁组青少年为主,占总病例数的80.56%;男性发病率显著高于女性,男、女性别发病数之比为1.68∶1.[结论]2009年甲型H1N1流感发病率较高,发病以8~24岁青少年为主,职业主要以学生为主,防治的重点应放在人口比较密集的场所,学生为甲型H1N1流感发病的高危人群.接种甲型H1N1流感疫苗是预防和控制甲型H1N1流感的重要措施之一.%[Objective] To analyze the epidemic data of A (H1N1) influenza in 2009 in Qinghai province, and provide evidence for the implementation of control strategies. [Methods] The epidemiological characteristics of A (H1N1) influenza were analyzed by descriptive epidemiological method, and data was analyzed by Excel 2003, [Results] It was shown that 2109 influenza A (H1N1) cases were reported in 2009 in Qinghai province, the incidence rate was 38.05/100 000. A total of 7 death cases reported, and the mortality rate was 0.13/100 000 and the fatality rate was 0.33%. The incidence rate of A (HIM) influenza ranked the third of infectious diseases A and B, The cases mainly concentrated in Xining City and Haidong District with relatively dense population. The season peak appeared from September to October, which accounted for 86.11% of the total cases. The person aged 8 to 24 years old were affected easily, which accounted for 80.56% of the total cases. The incidence rate in males was

  7. 2008-2010年天津市流行性感冒流行特征分析%Epidemic characteristics of influenza in Tianjin from 2008 to 2010

    Institute of Scientific and Technical Information of China (English)

    高芳旭; 王辉

    2012-01-01

    目的 了解2008年4月-2010年3月天津市流行性感冒(流感)流行特征.方法 通过“中国流感监测信息系统”收集天津市国家级哨点医院流感样病例(ILI)监测数据及病原学检测结果进行分析.结果 2008年4月-2010年3月天津市国家级哨点医院上报ILI 483 941例,流感样病例占门诊病例比例(ILI%)为12.79%,病例以15岁以下儿童为主.共采集ILI咽拭子标本5 816例,分离出流感病毒1 393株,阳性率为26.86%.2008-2009年流感优势毒株为季H1,2009-2010年以甲型H1N1为主.结论 2009年甲型H1N1流感全球大流行,天津市流感流行高峰提前,且ILI发病数和病毒分离阳性率有所增多.天津市非监测期ILI%较高,需进一步开展非监测期ILI病原学监测.%[ Objective ] To understand the epidemic characteristics of influenza in Tianjin from April 2008 to March 2010. [ Methods ] The monitoring data and pathogen detection results of influenza like illness (ILI) from Tianjin sentinel hospitals of national level were collected for analysis through National Influenza Surveillance Network. [Results] ] From April 2008 to March 2010, a total of 483 941 ILI cases were reported from Tianjin sentinel hospitals of national level, accounting for 12.79% of the total outpatient cases, and most cases were children aged≤15years. Totally 5 816 throat swab specimens were collected from patients with ILI, and 1 393 strains (26. 86% ) of influenza virus were isolated. The predominant strains turned from A 1 dring 2008-2009 to A (H1 N1) during 2009 to 2010. [ Conclusion ] In 2009, the influenza A (H1N1 ) virus caused a worldwide pandemic, the peak of influenza pandemic occurred earlier than last year, ILI cases and virus isolation positive rate had increased in Tianjin. In non-monitoring period of Tianjin, higher ILI% further monitoring of ILI pathogen needs to be carried out.

  8. The population impact of a large school-based influenza vaccination campaign.

    Directory of Open Access Journals (Sweden)

    Carlos G Grijalva

    Full Text Available BACKGROUND: The optimal vaccination strategy to mitigate the impact of influenza epidemics is unclear. In 2005, a countywide school-based influenza vaccination campaign was launched in Knox County, Tennessee (population 385,899. Approximately 41% and 48% of eligible county children aged 5-17 years were immunized with live attenuated influenza vaccine before the 2005-2006 and 2006-2007 influenza seasons, respectively. We sought to determine the population impact of this campaign. METHODS: Laboratory-confirmed influenza data defined influenza seasons. We calculated the incidence of medically attended acute respiratory illness attributable to influenza in Knox and Knox-surrounding counties (concurrent controls during consecutive seasons (5 precampaign and 2 campaign seasons using negative binomial regression and rate difference methods. Age-stratified analyses compared the incidence of emergency department (ED visits and hospitalizations attributable to influenza. RESULTS: During precampaign seasons, estimated ED visit rates attributable to influenza were 12.39 (95% CI: 10.34-14.44 per 1000 Knox children aged 5-17 years and similar in Knox-surrounding counties. During the campaign seasons, annual Knox influenza-associated ED visit rates declined relative to rates in Knox-surrounding counties: rate ratios 0.55 (95% CI: 0.27-0.83 and 0.70 (95% CI: 0.56-0.84 for the first and second campaign seasons, respectively. Overall, there were about 35% or 4.86 per 1000 fewer influenza-associated ED visits among Knox County children aged 5-17 years attributable to the campaign. No significant declines in Knox compared to surrounding counties were detected for influenza associated ED visits in children aged <5 years, all adults combined or selected adult age subgroups, although power for these analyses was limited. Alternate rate-difference analyses yielded consistent results. CONCLUSION: Vaccination of approximately 45% of Knox school-aged children with

  9. Temporal Patterns of Influenza A and B in Tropical and Temperate Countries: What Are the Lessons for Influenza Vaccination?

    Directory of Open Access Journals (Sweden)

    Saverio Caini

    Full Text Available Determining the optimal time to vaccinate is important for influenza vaccination programmes. Here, we assessed the temporal characteristics of influenza epidemics in the Northern and Southern hemispheres and in the tropics, and discuss their implications for vaccination programmes.This was a retrospective analysis of surveillance data between 2000 and 2014 from the Global Influenza B Study database. The seasonal peak of influenza was defined as the week with the most reported cases (overall, A, and B in the season. The duration of seasonal activity was assessed using the maximum proportion of influenza cases during three consecutive months and the minimum number of months with ≥80% of cases in the season. We also assessed whether co-circulation of A and B virus types affected the duration of influenza epidemics.212 influenza seasons and 571,907 cases were included from 30 countries. In tropical countries, the seasonal influenza activity lasted longer and the peaks of influenza A and B coincided less frequently than in temperate countries. Temporal characteristics of influenza epidemics were heterogeneous in the tropics, with distinct seasonal epidemics observed only in some countries. Seasons with co-circulation of influenza A and B were longer than influenza A seasons, especially in the tropics.Our findings show that influenza seasonality is less well defined in the tropics than in temperate regions. This has important implications for vaccination programmes in these countries. High-quality influenza surveillance systems are needed in the tropics to enable decisions about when to vaccinate.

  10. Peramivir injection in the treatment of acute influenza: a review of the literature.

    Science.gov (United States)

    Wester, Ashley; Shetty, Avinash K

    2016-01-01

    Influenza virus infection is a major cause of morbidity and mortality in children and adults globally. Seasonal epidemics are common due to the rapid virus evolution, whereas the frequent emergence of antigenic variants can result in pandemics and sporadic/endemic avian influenza virus infections. Although annual vaccination is the mainstay for influenza prevention and control, the use of antiviral agents must be considered for treatment and prophylaxis against influenza. Currently available antiviral drugs include neuraminidase inhibitors (NAIs), adamantanes, and a novel polymerase inhibitor (favipiravir). Peramivir is a recently US Food and Drug Administration-approved NAI for the treatment of acute uncomplicated influenza in adults. The chemical structure of peramivir allows it to bind to the influenza neuraminidase with much higher affinity than oseltamivir. Peramivir is effective against a variety of influenza A and B subtypes and has a lower half-maximal inhibitory concentration compared to other NAIs in in vitro studies. Peramivir can be administered intravenously, a route that is favorable for hospitalized, critically ill patients with influenza. The long half-life of peramivir allows for once-daily dosing. The drug is eliminated primarily by the kidneys, warranting dose adjustments in patients with renal dysfunction. Studies have assessed the clinical efficacy of peramivir for treatment of pandemic influenza A (H1N1). Although anecdotal evidence supports the use of peramivir in pediatric patients, pregnant women, and hospitalized patients with severe influenza receiving continuous renal replacement therapy and extracorporeal membrane oxygenation, well-designed, controlled clinical trials should be conducted in order to assess its clinical efficacy in these patient populations.

  11. Lessons from the epidemiological surveillance program, during the influenza A (H1N1 virus epidemic, in a reference university hospital of Southeastern Brazil Lições aprendidas pelo programa de vigilância epidemiológica, durante a epidemia pelo vírus da influenza A (H1N1, em um hospital universitário na região sudeste do Brasil

    Directory of Open Access Journals (Sweden)

    Maria Luiza Moretti

    2011-08-01

    Full Text Available INTRODUCTION: The case definition of influenza-like illness (ILI is a powerful epidemiological tool during influenza epidemics. METHODS: A prospective cohort study was conducted to evaluate the impact of two definitions used as epidemiological tools, in adults and children, during the influenza A H1N1 epidemic. Patients were included if they had upper respiratory samples tested for influenza by real-time reverse transcriptase polymerase chain reaction during two periods, using the ILI definition (coughing + temperature > 38ºC in period 1, and the definition of severe acute respiratory infection (ARS (coughing + temperature > 38ºC and dyspnoea in period 2. RESULTS: The study included 366 adults and 147 children, covering 243 cases of ILI and 270 cases of ARS. Laboratory confirmed cases of influenza were higher in adults (50% than in children (21.6% ( p INTRODUÇÃO: A definição de síndrome gripal é uma ferramenta epidemiológica importante durante epidemias de influenza. MÉTODOS: Foi conduzido estudo de coorte prospectivo para avaliar o impacto das definições de síndrome gripal (SG e doença respiratória aguda grave (DRAG como ferramenta de vigilância epidemiológica, em adultos e crianças, durante a epidemia de influenza A H1N1. Os pacientes foram incluídos se tivessem coleta de secreção respiratória alta testada por PCR real time para o vírus da influenza. Os dados clínicos e epidemiológicos foram estudados comparando-se dois períodos: período 1: SG (tosse + temperatura > 38ºC, e período 2: DRAG (tosse + temperatura > 38 e dispnéia. RESULTADOS: Foram incluídos 366 adultos e 147 crianças, em um total de 243 casos de SG e 270 DRAG. A confirmação laboratorial de influenza em adultos (50% foi significativamente maior do que em crianças (21,6% (p < 0,0001 e a definição de SG foi mais confirmatória de infecção por influenza (53% do que DRAG (24,4% (p < 0,0001. Adultos referiam mais calafrios e mialgias do que as

  12. 人感染高致病性禽流感的流行与预防%Epidemic and prevention of human infections with highly pathogenic avian influenza

    Institute of Scientific and Technical Information of China (English)

    李刚

    2010-01-01

    @@ 人感染高致病性禽流行性感冒(human infections with highly pathogenic avian influenza)简称人禽流感,是指人感染甲型禽流感病毒(avian influenza virus,AIV)某些亚型的毒株引起的急性呼吸道传染病.1997年5月,我国香港特别行政区1例3岁儿童死于不明原因的多脏器功能哀竭,同年8月经美国疾病预防和摔制中心以及世界卫牛组织(WHO)荷兰鹿特丹国家流感中心鉴定为禽甲型流感病毒H5N1引起的人类流感,这是世界上首次证实禽甲型流感病毒H5N1感染人类.

  13. Mortality attributable to seasonal and pandemic influenza, Australia, 2003 to 2009, using a novel time series smoothing approach.

    Directory of Open Access Journals (Sweden)

    David J Muscatello

    Full Text Available BACKGROUND: Official statistics under-estimate influenza deaths. Time series methods allow the estimation of influenza-attributable mortality. The methods often model background, non-influenza mortality using a cyclic, harmonic regression model based on the Serfling approach. This approach assumes that the seasonal pattern of non-influenza mortality is the same each year, which may not always be accurate. AIM: To estimate Australian seasonal and pandemic influenza-attributable mortality from 2003 to 2009, and to assess a more flexible influenza mortality estimation approach. METHODS: We used a semi-parametric generalized additive model (GAM to replace the conventional seasonal harmonic terms with a smoothing spline of time ('spline model' to estimate influenza-attributable respiratory, respiratory and circulatory, and all-cause mortality in persons aged <65 and ≥ 65 years. Influenza A(H1N1pdm09, seasonal influenza A and B virus laboratory detection time series were used as independent variables. Model fit and estimates were compared with those of a harmonic model. RESULTS: Compared with the harmonic model, the spline model improved model fit by up to 20%. In <65 year-olds, the estimated respiratory mortality attributable to pandemic influenza A(H1N1pdm09 was 0.5 (95% confidence interval (CI, 0.3, 0.7 per 100,000; similar to that of the years with the highest seasonal influenza A mortality, 2003 and 2007 (A/H3N2 years. In ≥ 65 year-olds, the highest annual seasonal influenza A mortality estimate was 25.8 (95% CI 22.2, 29.5 per 100,000 in 2003, five-fold higher than the non-statistically significant 2009 pandemic influenza estimate in that age group. Seasonal influenza B mortality estimates were negligible. CONCLUSIONS: The spline model achieved a better model fit. The study provides additional evidence that seasonal influenza, particularly A/H3N2, remains an important cause of mortality in Australia and that the epidemic of pandemic influenza

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

    Institute of Scientific and Technical Information of China (English)

    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

    2011-01-01

    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.

  15. Influenza outbreak during Sydney World Youth Day 2008: the utility of laboratory testing and case definitions on mass gathering outbreak containment.

    Directory of Open Access Journals (Sweden)

    Sebastiaan J van Hal

    Full Text Available BACKGROUND: Influenza causes annual epidemics and often results in extensive outbreaks in closed communities. To minimize transmission, a range of interventions have been suggested. For these to be effective, an accurate and timely diagnosis of influenza is required. This is confirmed by a positive laboratory test result in an individual whose symptoms are consistent with a predefined clinical case definition. However, the utility of these clinical case definitions and laboratory testing in mass gathering outbreaks remains unknown. METHODS AND RESULTS: An influenza outbreak was identified during World Youth Day 2008 in Sydney. From the data collected on pilgrims presenting to a single clinic, a Markov model was developed and validated against the actual epidemic curve. Simulations were performed to examine the utility of different clinical case definitions and laboratory testing strategies for containment of influenza outbreaks. Clinical case definitions were found to have the greatest impact on averting further cases with no added benefit when combined with any laboratory test. Although nucleic acid testing (NAT demonstrated higher utility than indirect immunofluorescence antigen or on-site point-of-care testing, this effect was lost when laboratory NAT turnaround times was included. The main benefit of laboratory confirmation was limited to identification of true influenza cases amenable to interventions such as antiviral therapy. CONCLUSIONS: Continuous re-evaluation of case definitions and laboratory testing strategies are essential for effective management of influenza outbreaks during mass gatherings.

  16. Cooperativity between CD8+ T cells, non-neutralizing antibodies, and alveolar macrophages is important for heterosubtypic influenza virus immunity.

    Directory of Open Access Journals (Sweden)

    Brian J Laidlaw

    2013-03-01

    Full Text Available Seasonal epidemics of influenza virus result in ∼36,000 deaths annually in the United States. Current vaccines against influenza virus elicit an antibody response specific for the envelope glycoproteins. However, high mutation rates result in the emergence of new viral serotypes, which elude neutralization by preexisting antibodies. T lymphocytes have been reported to be capable of mediating heterosubtypic protection through recognition of internal, more conserved, influenza virus proteins. Here, we demonstrate using a recombinant influenza virus expressing the LCMV GP33-41 epitope that influenza virus-specific CD8+ T cells and virus-specific non-neutralizing antibodies each are relatively ineffective at conferring heterosubtypic protective immunity alone. However, when combined virus-specific CD8 T cells and non-neutralizing antibodies cooperatively elicit robust protective immunity. This synergistic improvement in protective immunity is dependent, at least in part, on alveolar macrophages and/or other lung phagocytes. Overall, our studies suggest that an influenza vaccine capable of eliciting both CD8+ T cells and antibodies specific for highly conserved influenza proteins may be able to provide heterosubtypic protection in humans, and act as the basis for a potential "universal" vaccine.

  17. KINETIC PROFILE OF INFLUENZA VIRUS INFECTION IN THREE RAT STRAINS

    Science.gov (United States)

    AbstractInfluenza infection is a respiratory disease of viral origin that can cause major epidemics in man. The influenza virus infects and damages epithelial cells of the respiratory tract and causes pneumonia. Lung lesions of mice infected with influenza virus resembl...

  18. Bestrijding van aviaire influenza onder pluimvee: vaccinatie als aanvullende mogelijkheid

    NARCIS (Netherlands)

    Aarle, P van; Breytenbach, J; Schueller, S

    2006-01-01

    Since mid-December 2003, highly pathogenic avian influenza (HPAI) has caused an epidemic in the Asian poultry sector and avian influenza cases have been reported in Europe, the Middle East and Africa. Human fatalities catapulted avian influenza into the public arena with fears of a possible global i

  19. Design of the Dutch prevention of influenza, surveillance and management (PRISMA) study

    NARCIS (Netherlands)

    Hak, E; van Loon, S; Buskens, E; van Essen, G A; de Bakker, D; Tacken, M A J B; van Hout, B A; Grobbee, D E; Verheij, Th J M

    2003-01-01

    Rationale and design of a study on the cost-effectiveness of the Dutch influenza vaccination campaign are described. During two influenza epidemics, about 75,000 primary care patients recommended for influenza vaccination are included. Cases have fatal or non-fatal influenza, pneumonia, otitis media

  20. Design of the Dutch prevention of influenza, surveillance and management (PRISMA) study.

    NARCIS (Netherlands)

    Hak, E.; Loon, S. van; Buskens, E.; Essen, G.A. van; Bakker, D. de; Tacken, M.A.J.B.; Hout, B.A. van; Grobbee, D.E.; Verheij, T.J.M.

    2003-01-01

    Rationale and design of a study on the cost-effectiveness of the Dutch influenza vaccination campaign are described. During two influenza epidemics, about 75,000 primary care patients recommended for influenza vaccination are included. Cases have fatal or non-fatal influenza, pneumonia, otitis media

  1. Seasonal influenza activity for 2005-2006 season seems to be ending in most European countries.

    NARCIS (Netherlands)

    Paget, W.J.; Meijer, A.; Falcao, J.M.; Jong, J.C. de; Kyncl, J.; Meerhoff, T.J.; Meuwissen, L.E.; Nicoll, A.; Velden, J. van der

    2006-01-01

    During the 2005-2006 season, seasonal influenza epidemics started late in countries across Europe. Clinical influenza activity has only reached moderate levels and has mainly been associated with influenza B viruses. There has been co-circulation of influenza A and B viruses in many countries, and i

  2. Cause analysis and nursing measures for epidemic situation of influenza outbreak in the psychiatric ward%精神科病房暴发流行性感冒疫情的原因分析及护理对策

    Institute of Scientific and Technical Information of China (English)

    章文峰; 殷凤莲

    2014-01-01

    目的:探讨精神科病房暴发流行性感冒疫情的原因及对策。方法选取本院一精神科病房流行性感冒疫情暴发的32例住院精神病患者,将其按年龄分为<40岁组和≥40岁组,按住院时间分为<90 d组和≥90 d组,按病程分为<3年组和≥3年组,按疾病类型分为精神分裂症组和其他精神障碍组。结果年龄<40岁和≥40岁组、住院时间<90 d和住院时间≥90 d组、病程<3年和病程≥3年组、精神分裂症与其他精神障碍组暴发流行性感冒的感染率比较,差异有统计学意义(P<0.01)。结论患者年龄越大、住院时间越长、病程越长,精神分裂症患者更易被感染,应当根据专科易感因素制订合理的护理措施,加强住院患者的生活护理,积极引导患者进行适当的体育锻炼,增强机体抵抗力,改善病房管理,做好各项护理措施,积极控制感染和宣传防病意识,降低医院感染风险。%Objective To explore the cause and measures for epidemic situation of influenza outbreak in the psychiatric ward. Methods 32 psychiatric patients hospitalized in the first psychiatric ward of our hospital during influenza out-break were selected and assigned to the<40 years old group and≥40 years old group according to the age,the hospital stay<90 days group and the≥90 days group according to the hospital stay,the course of disease<3 years group and≥3 years group according to the course of disease,and the schizophrenia group and the group with other mental disorder ac-cording to the disease type. Results There was a statistical difference of infection rate of outbreaking the influenza be-tween the age<40 years old group and ≥40 years old group,between the hospital stay<90 days group and the ≥90 days group,between the course of disease<3 years group and ≥3 years group,between the schizophrenia group and the group with other mental disorder (P<0.01). Conclusion Patients with senility

  3. 76 FR 78658 - Webinar Overview of the National Vaccine Advisory Committee Healthcare Personnel Influenza...

    Science.gov (United States)

    2011-12-19

    ... Influenza Vaccination Subgroup's Draft Report and Draft Recommendations for Achieving the Healthy People 2020 Annual Coverage Goals for Influenza Vaccination in Healthcare Personnel AGENCY: National Vaccine... of the National Vaccine Advisory Committee (NVAC), Healthcare Personnel Influenza...

  4. 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

    Directory of Open Access Journals (Sweden)

    2009-10-01

    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

  5. Influenza: From zoonosis to pandemic

    OpenAIRE

    2016-01-01

    Probable epidemic influenza outbreaks have been described as early as the 5th century BC, as part of the Cough of Perinthus associated with the winter solstice, in Hippocrates' Corpus Hippocraticum “Of the Epidemics” [1]. The word “influenza” was first introduced in the 16th century, defining the illness of the cold season that in the early 1930s was shown to be caused by “filterable agents”, since then called influenza viruses. Three types or genera of influenza viruses have been recognised ...

  6. Avian influenza outbreak management: action at time of confirmation, depopulation and disposal methods; the 'Belgian experience' during the H7N7 highly pathogenic avian influenza epidemic in 2003.

    Science.gov (United States)

    van den Berg, T; Houdart, P

    2008-01-01

    Eradication of H5 and H7 influenza in a positive flock will include mass depopulation of birds, containment and inactivation of the virus in the carcasses and litter, and decontamination of the facility. A quick response is desired in the event of a disease outbreak. Ideally, birds should be depopulated within 24 h after detecting the virus. Mass depopulation of birds must be performed in a humane manner while minimizing human health and biosecurity risks. In the framework of the European legislation, a number of methods are authorized for the killing of poultry for processing prior to marketing. However, during emergencies such as a disease outbreak, there are fewer options. The current most commonly used procedures for large-scale emergency depopulation of birds consist of exposing poultry to CO or CO(2) gas. Both gasses have been used in Belgium during the H7N7 crisis in 2003. The gassing procedures include whole house gassing, portable panel enclosures, cage cabinets, containers and polyethylene tent method. Whole house gassing requires sealing the house to prevent gas leakage and, using specialized equipment, introducing large volumes of gas evenly over the birds. All procedures are very labour intensive, create a biosecurity risk and require a large number of personnel. There are considerable region-to-region differences in emergency depopulation techniques and disposal of carcasses and infected material. Because of the differences in bird type and species, management, housing and stocking density, it is difficult to propose a depopulation technique that will be suitable for all circumstances. Safety of the human operators is an increasing concern with all H5 and H7 strains and in particular with the highly pathogenic H5N1 strain. Researchers and commercial poultry companies in the United States recently established that non-toxic water-based foam with a certain bubble size presents a practicable, effective and humane method for mass depopulation. Foam of the

  7. Analysis on the epidemic characteristics of influenza in Guangzhou from 2011 to 2013%2011-2013年广州地区发热呼吸道感染患者的人流感病毒监测及其亚型的流行特征分析

    Institute of Scientific and Technical Information of China (English)

    陈敏静; 徐霖; 钟慧玲; 张素粉; 罗虹娇; 庹玖玲; 张甜; 曹开源

    2015-01-01

    Objective To investigate the prevalence and epidemic characteristics of influenza in Guangzhou from 2011 to 2013,and lay the foundation for a further understanding of human influenza virus.Methods A total of 2085 throat swab specimens of patients with respiratory tract virus infection and relevant clinical information were collected from 2011 to 2013 in Guangzhou. Multiplex PCR was used to detect the human influenza virus and its subtypes.Results Among all specimens,237 patients were infected with human influenza virus during 2011 to 2013,with a positive rate of 11.4%. The human influenza virus A and B positive samples were 202 and 35,respectively,with a positive rate of respectively 9.68% and 1.68%. The student group including primarily,secondary and university students had the highest influenza positive rate;pediatric department of clinics had the highest attendant rate;the male to female ratio was 1.34:1,no significant difference. Most of the positive samples were type A influenza virus. Type A influenza virus had its peak circulation in spring(March-May);Influenza B virus was more scattered throughout the year. In Guangzhou the age groups susceptible to human influenza virus infection were 0~6 year-old,7~17 year-old and the 18~39 year-old;the incidences of different each age group was significantly different.The highest incidence of Influenza A virus infection was also occurred in 18~39 year-old age group,but the incidence of influenza A infection had no significant differences among different age groups.The highest incidence of influenza B virus infection was occurred in the 7~17 year-old age group.Conclusions 2011-2013 Guangzhou had no large-scale of human influenza outbreaks.The human influenza was mainly human influenza A virus infection,and was sporadically cause by influenza B.There was no infection caused by influenza C virus.Epidemic peaked in March to May,and the 18 to 39-year-old age group had the highest incidence.%目的 了解2011-2013年广

  8. Influenza vaccination for healthcare workers: from a simple concept to a resistant issue?

    Science.gov (United States)

    Gavazzi, Gaëtan

    2009-06-01

    Different strategies for the management of influenza epidemics are particularly important in elderly population. High morbidity and mortality rates are associated with influenza in the elderly, and annual vaccination against flu is considered to be the best cost-effective strategy. However, its efficiency is reduced in older adults and only half of them are protected. Several studies show that vaccinating healthcare workers is an efficient way of decreasing mortality rates in nursing home residents within influenza season. National and international public health authorities recommend therefore healthcare worker vaccinations for up to 5 years. However, influenza healthcare worker vaccination coverages are still low. Here we summarize data regarding the justification of healthcare worker vaccination, the efficiency of this strategy, the reasons of the reluctance of vaccination, the means and results of interventional programs and, then, focus on the debate of a mandatory healthcare worker influenza vaccination. Because several interventional programs are efficient but still need high financial and human support, only a strong political-will can improve this chosen strategy.

  9. Evaluation of Three Live Attenuated H2 Pandemic Influenza Vaccine Candidates in Mice and Ferrets

    Science.gov (United States)

    Chen, Grace L.; Lamirande, Elaine W.; Cheng, Xing; Torres-Velez, Fernando; Orandle, Marlene; Jin, Hong; Kemble, George

    2014-01-01

    ABSTRACT H2 influenza viruses have not circulated in humans since 1968, and therefore a significant portion of the population would be susceptible to infection should H2 influenza viruses reemerge. H2 influenza viruses continue to circulate in avian reservoirs worldwide, and these reservoirs are a potential source from which these viruses could emerge. Three reassortant cold-adapted (ca) H2 pandemic influenza vaccine candidates with hemagglutinin (HA) and neuraminidase (NA) genes derived from the wild-type A/Japan/305/1957 (H2N2) (Jap/57), A/mallard/6750/1978 (H2N2) (mal/78), or A/swine/MO/4296424/2006 (H2N3) (sw/06) viruses and the internal protein gene segments from the A/Ann Arbor/6/60 ca virus were generated by plasmid-based reverse genetics (Jap/57 ca, mal/78 ca, and sw/06 ca, respectively). The vaccine candidates exhibited the in vitro phenotypes of temperature sensitivity and cold adaptation and were restricted in replication in the respiratory tract of ferrets. In mice and ferrets, the vaccines elicited neutralizing antibodies and conferred protection against homologous wild-type virus challenge. Of the three candidates, the sw/06 ca vaccine elicited cross-reactive antibodies and provided significant protection against the greatest number of heterologous viruses. These observations suggest that the sw/06 ca vaccine should be further evaluated in a clinical trial as an H2 pandemic influenza vaccine candidate. IMPORTANCE Influenza pandemics arise when novel influenza viruses are introduced into a population with little prior immunity to the new virus and often result in higher rates of illness and death than annual seasonal influenza epidemics. An influenza H2 subtype virus caused a pandemic in 1957, and H2 viruses circulated in humans till 1968. H2 influenza viruses continue to circulate in birds, and the development of an H2 influenza vaccine candidate is therefore considered a priority in preparing for future pandemics. However, we cannot predict whether a

  10. Epidemics: Lessons from the past and current patterns of response

    Science.gov (United States)

    Martin, Paul

    2008-09-01

    Hippocrates gave the term 'epidemic' its medical meaning. From antiquity to modern times, the meaning of the word epidemic has continued to evolve. Over the centuries, researchers have reached an understanding of the varying aspects of epidemics and have tried to combat them. The role played by travel, trade, and human exchanges in the propagation of epidemic infectious diseases has been understood. In 1948, the World Health Organization was created and given the task of advancing ways of combating epidemics. An early warning system to combat epidemics has been implemented by the WHO. The Global Outbreak Alert and Response Network (GOARN) is collaboration between existing institutions and networks that pool their human and technical resources to fight outbreaks. Avian influenza constitutes currently the most deadly epidemic threat, with fears that it could rapidly reach pandemic proportions and put several thousands of lives in jeopardy. Thanks to the WHO's support, most of the world's countries have mobilised and implemented an 'Action Plan for Pandemic Influenza'. As a result, most outbreaks of the H5N1 avian flu virus have so far been speedily contained. Cases of dengue virus introduction in countries possessing every circumstance required for its epidemic spread provide another example pertinent to the prevention of epidemics caused by vector-borne pathogens.

  11. Influenza virus infection among pediatric patients reporting diarrhea and influenza-like illness

    Directory of Open Access Journals (Sweden)

    Uyeki Timothy M

    2010-01-01

    Full Text Available Abstract Background Influenza is a major cause of morbidity and hospitalization among children. While less often reported in adults, gastrointestinal symptoms have been associated with influenza in children, including abdominal pain, nausea, vomiting, and diarrhea. Methods From September 2005 and April 2008, pediatric patients in Indonesia presenting with concurrent diarrhea and influenza-like illness were enrolled in a study to determine the frequency of influenza virus infection in young patients presenting with symptoms less commonly associated with an upper respiratory tract infection (URTI. Stool specimens and upper respiratory swabs were assayed for the presence of influenza virus. Results Seasonal influenza A or influenza B viral RNA was detected in 85 (11.6% upper respiratory specimens and 21 (2.9% of stool specimens. Viable influenza B virus was isolated from the stool specimen of one case. During the time of this study, human infections with highly pathogenic avian influenza A (H5N1 virus were common in the survey area. However, among 733 enrolled subjects, none had evidence of H5N1 virus infection. Conclusions The detection of influenza viral RNA and viable influenza virus from stool suggests that influenza virus may be localized in the gastrointestinal tract of children, may be associated with pediatric diarrhea and may serve as a potential mode of transmission during seasonal and epidemic influenza outbreaks.

  12. Human Influenza Virus Infections.

    Science.gov (United States)

    Peteranderl, Christin; Herold, Susanne; Schmoldt, Carole

    2016-08-01

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

  13. Global influenza surveillance with Laplacian multidimensional scaling

    Institute of Scientific and Technical Information of China (English)

    Xi-chuan ZHOU; Fang TANG; Qin LI; Sheng-dong HU; Guo-jun LI; Yun-jian JIA; Xin-ke LI; Yu-jie FENG

    2016-01-01

    The Global Influenza Surveillance Network is crucial for monitoring epidemic risk in participating countries. However, at present, the network has notable gaps in the developing world, principally in Africa and Asia where laboratory capabilities are limited. Moreover, for the last few years, various influenza viruses have been continuously emerging in the resource-limited countries, making these surveillance gaps a more imminent challenge. We present a spatial-transmission model to estimate epidemic risks in the countries where only partial or even no surveillance data are available. Motivated by the observation that countries in the same influenza transmission zone divided by the World Health Organization had similar transmission patterns, we propose to estimate the influenza epidemic risk of an unmonitored country by incorporating the surveillance data reported by countries of the same transmission zone. Experiments show that the risk estimates are highly correlated with the actual influenza morbidity trends for African and Asian countries. The proposed method may provide the much-needed capability to detect, assess, and notify potential influenza epidemics to the developing world.

  14. Spatial distribution and risk factors of influenza in Jiangsu province, China, based on geographical information system.

    Science.gov (United States)

    Zhang, Jia-Cheng; Liu, Wen-Dong; Liang, Qi; Hu, Jian-Li; Norris, Jessie; Wu, Ying; Bao, Chang-Jun; Tang, Fen-Yang; Huang, Peng; Zhao, Yang; Yu, Rong-Bin; Zhou, Ming-Hao; Shen, Hong-Bing; Chen, Feng; Peng, Zhi-Hang

    2014-05-01

    Influenza poses a constant, heavy burden on society. Recent research has focused on ecological factors associated with influenza incidence and has also studied influenza with respect to its geographic spread at different scales. This research explores the temporal and spatial parameters of influenza and identifies factors influencing its transmission. A spatial autocorrelation analysis, a spatial-temporal cluster analysis and a spatial regression analysis of influenza rates, carried out in Jiangsu province from 2004 to 2011, found that influenza rates to be spatially dependent in 2004, 2005, 2006 and 2008. South-western districts consistently revealed hotspots of high-incidence influenza. The regression analysis indicates that railways, rivers and lakes are important predictive environmental variables for influenza risk. A better understanding of the epidemic pattern and ecological factors associated with pandemic influenza should benefit public health officials with respect to prevention and controlling measures during future epidemics.

  15. Spatial distribution and risk factors of influenza in Jiangsu province, China, based on geographical information system

    Directory of Open Access Journals (Sweden)

    Jia-Cheng Zhang

    2014-05-01

    Full Text Available Influenza poses a constant, heavy burden on society. Recent research has focused on ecological factors associated with influenza incidence and has also studied influenza with respect to its geographic spread at different scales. This research explores the temporal and spatial parameters of influenza and identifies factors influencing its transmission. A spatial autocorrelation analysis, a spatial-temporal cluster analysis and a spatial regression analysis of influenza rates, carried out in Jiangsu province from 2004 to 2011, found that influenza rates to be spatially dependent in 2004, 2005, 2006 and 2008. South-western districts consistently revealed hotspots of high-incidence influenza. The regression analysis indicates that railways, rivers and lakes are important predictive environmental variables for influenza risk. A better understanding of the epidemic pattern and ecological factors associated with pandemic influenza should benefit public health officials with respect to prevention and controlling measures during future epidemics.

  16. Seasonal influenza vaccine policies, recommendations and use in the World Health Organization’s Western Pacific Region Original Research

    Directory of Open Access Journals (Sweden)

    Members of the Western Pacific Region Global Influenza Surveillance and Response System

    2013-09-01

    Full Text Available Objective: Vaccination is the most effective way to prevent seasonal influenza and its severe outcomes. The objective of our study was to synthesize information on seasonal influenza vaccination policies, recommendations and practices in place in 2011 for all countries and areas in the Western Pacific Region of the World Health Organization (WHO. Methods: Data were collected via a questionnaire on seasonal influenza vaccination policies, recommendations and practices in place in 2011. Results: Thirty-six of the 37 countries and areas (97% responded to the survey. Eighteen (50% reported having established seasonal influenza vaccination policies, an additional seven (19% reported having recommendations for risk groups for seasonal influenza vaccination only and 11 (30% reported having no policies or recommendations in place. Of the 25 countries and areas with policies or recommendations, health-care workers and the elderly were most frequently recommended for vaccination; 24 (96% countries and areas recommended vaccinating these groups, followed by pregnant women (19 [76%], people with chronic illness (18 [72%] and children (15 [60%]. Twenty-six (72% countries and areas reported having seasonal influenza vaccines available through public funding, private market purchase or both. Most of these countries and areas purchased only enough vaccine to cover 25% or less of their populations. Discussion: In light of the new WHO position paper on influenza vaccines published in 2012 and the increasing availability of country-specific data, countries and areas should consider reviewing or developing their seasonal influenza vaccination policies to reduce morbidity and mortality associated with annual epidemics and as part of ongoing efforts for pandemic preparedness.

  17. Siting epidemic disease: 3 centuries of American history.

    Science.gov (United States)

    Rosenberg, Charles E

    2008-02-15

    Epidemics of infectious disease have always played a role in American history, and such epidemics are sited in time and place and configured in terms of ecology and demography, available medical knowledge, and cultural values and collective experience. The mix of these variables has changed dramatically since the theocratic world of 17th-century New England, but the relevance of each remains. Avian influenza already exists virtually in Western society in terms of planning, global networks, laboratory research, social expectations, media representations, and a specific shared history based on the memory of the 1918 influenza pandemic.

  18. La influenza, un problema vigente de salud pública Influenza, an existing public health problem

    Directory of Open Access Journals (Sweden)

    Juan García-García

    2006-06-01

    particular, during winter months and having an elevated effect on public health worldwide. The disease has high morbidity rates for people of all ages and particularly high mortality rates for children, adults over 60 years old, patients with chronic illnesses and pregnant women. Prevention control strategies include vaccination using inactivated, subunit or genetically modified virus vaccines. Influenza in humans is caused by two subtypes of influenza virus A and one of influenza virus B. The influenza virus A that affects humans mutates easily, thereby often causing new antigenic variants of each subtype to emerge, requiring the inclusion of such variants in annual vaccines in order to assure proper immunization of the population. The influenza pandemic refers to the introduction and later worldwide spread of a new influenza virus in the human population, which occurs sporadically. Due to the lack of immunity in humans against the new virus, serious epidemics can be provoked resulting in high morbidity and mortality rates. Historically, influenza pandemics are a result of the transmission of the virus from birds to humans, or the transfer of such genes to seasonal influenza. Wild waterfowl -both migratory and shore birds- carry a large diversity of influenza virus subtypes, which are eventually transmitted to domestic birds. Some of those viruses cross the species barrier and infect mammals, including humans. The adaptation process of the avian virus to mammal hosts requires time. Therefore, the presentation of these cases can take several years. Since December 2003, in several Southeast Asian countries a large proportion of domestic birds have been affected by an avian influenza epidemic (subtype H5N1. By Februrary 2006, the epidemic had already affected countries in Europe and Africa, having a significant economic impact on commercial poultry due to the more than 180 million birds that were sacrificed. Some strains of this avian influenza virus have directly, although

  19. Compounds with anti-influenza activity: present and future of strategies for the optimal treatment and management of influenza. Part I: Influenza life-cycle and currently available drugs.

    Science.gov (United States)

    Gasparini, R; Amicizia, D; Lai, P L; Bragazzi, N L; Panatto, D

    2014-09-01

    Influenza is a contagious respiratory acute viral disease characterized by a short incubation period, high fever and respiratory and systemic symptoms. The burden of influenza is very heavy. Indeed, the World Health Organization (WHO) estimates that annual epidemics affect 5-15% of the world's population, causing up to 4-5 million severe cases and from 250,000 to 500,000 deaths. In order to design anti-influenza molecules and compounds, it is important to understand the complex replication cycle of the influenza virus. Replication is achieved through various stages. First, the virus must engage the sialic acid receptors present on the free surface of the cells of the respiratory tract. The virus can then enter the cells by different routes (clathrin-mediated endocytosis or CME, caveolae-dependent endocytosis or CDE, clathrin-caveolae-independent endocytosis, or macropinocytosis). CME is the most usual pathway; the virus is internalized into an endosomal compartment, from which it must emerge in order to release its nucleic acid into the cytosol. The ribonucleoprotein must then reach the nucleus in order to begin the process of translation of its genes and to transcribe and replicate its nucleic acid. Subsequently, the RNA segments, surrounded by the nucleoproteins, must migrate to the cell membrane in order to enable viral assembly. Finally, the virus must be freed to invade other cells of the respiratory tract. All this is achieved through a synchronized action of molecules that perform multiple enzymatic and catalytic reactions, currently known only in part, and for which many inhibitory or competitive molecules have been studied. Some of these studies have led to the development of drugs that have been approved, such as Amantadine, Rimantadine, Oseltamivir, Zanamivir, Peramivir, Laninamivir, Ribavirin and Arbidol. This review focuses on the influenza life-cycle and on the currently available drugs, while potential antiviral compounds for the prevention and

  20. Orally administered Salacia reticulata extract reduces H1N1 influenza clinical symptoms in murine lung tissues putatively due to enhanced natural killer cell activity

    Directory of Open Access Journals (Sweden)

    Gustavo Adolfo Romero-Pérez

    2016-03-01

    Full Text Available Influenza is a major cause of respiratory tract infection. Although most cases do not require further hospitalization, influenza periodically causes epidemics in humans that can potentially infect and kill millions of people. To countermeasure this threat, new vaccines need to be developed annually to match emerging influenza viral strains with increased resistance to existing vaccines. Thus, there is a need for finding and developing new anti-influenza viral agents as alternatives to current treatments. Here, we tested the antiviral effects of an extract from the stems and roots of Salacia reticulata (SSRE, a plant rich in phytochemicals such as salacinol, kotalanol and catechins, on H1N1 influenza virus-infected mice. Following oral administration of 0.6 mg/day of SSRE, the incidence of coughing decreased in 80% of mice, and only one case of severe pulmonary inflammation was detected. Moreover, when compared with mice given Lactobacillus casei JCM1134, a strain previously shown to help increase in vitro NK cell activity, SSRE-administered mice showed greater and equal NK cell activity in splenocytes and pulmonary cells, respectively, at high effector cell:target cell ratios. Next, to test whether or not SSRE would exert protective effects against influenza in the absence of gut microbiota, mice were given antibiotics before being inoculated influenza virus and subsequently administered SSRE. SSRE administration induced an increase in NK cell activity in splenocytes and pulmonary cells at levels similar to those detected in mice not treated with antibiotics. Based on our results, it can be concluded that phytochemicals in the SSRE exerted protective effects against influenza infection putatively via modulation of the immune response including enhancement of NK cell activity, although some protective effects were not necessarily through modulation of gut microbiota. Further investigation is necessary to elucidate the molecular mechanisms

  1. Orally Administered Salacia reticulata Extract Reduces H1N1 Influenza Clinical Symptoms in Murine Lung Tissues Putatively Due to Enhanced Natural Killer Cell Activity

    Science.gov (United States)

    Romero-Pérez, Gustavo A.; Egashira, Masayo; Harada, Yuri; Tsuruta, Takeshi; Oda, Yuriko; Ueda, Fumitaka; Tsukahara, Takamitsu; Tsukamoto, Yasuhiro; Inoue, Ryo

    2016-01-01

    Influenza is a major cause of respiratory tract infection. Although most cases do not require further hospitalization, influenza periodically causes epidemics in humans that can potentially infect and kill millions of people. To countermeasure this threat, new vaccines need to be developed annually to match emerging influenza viral strains with increased resistance to existing vaccines. Thus, there is a need for finding and developing new anti-influenza viral agents as alternatives to current treatments. Here, we tested the antiviral effects of an extract from the stems and roots of Salacia reticulata (SSRE), a plant rich in phytochemicals, such as salacinol, kotalanol, and catechins, on H1N1 influenza virus-infected mice. Following oral administration of 0.6 mg/day of SSRE, the incidence of coughing decreased in 80% of mice, and only one case of severe pulmonary inflammation was detected. Moreover, when compared with mice given Lactobacillus casei JCM1134, a strain previously shown to help increase in vitro natural killer (NK) cell activity, SSRE-administered mice showed greater and equal NK cell activity in splenocytes and pulmonary cells, respectively, at high effector cell:target cell ratios. Next, to test whether or not SSRE would exert protective effects against influenza in the absence of gut microbiota, mice were given antibiotics before being inoculated influenza virus and subsequently administered SSRE. SSRE administration induced an increase in NK cell activity in splenocytes and pulmonary cells at levels similar to those detected in mice not treated with antibiotics. Based on our results, it can be concluded that phytochemicals in the SSRE exerted protective effects against influenza infection putatively via modulation of the immune response, including enhancement of NK cell activity, although some protective effects were not necessarily through modulation of gut microbiota. Further investigation is necessary to elucidate the molecular mechanisms

  2. Influenza vaccination

    DEFF Research Database (Denmark)

    Østerhus, Sven Frederick

    2015-01-01

    The Cochrane Library was systematically searched for meta-analyses regarding influenza vaccination of various populations, both healthy and sick. An effect in reducing the number of cases of influenza, influenza-like illness or complications to influenza was found in some studies, but, generally......, the quality of the studies was low, and several studies lacked hard clinical endpoints. Data on adverse effects were scarce. More randomised controlled trials investigating the effects of influenza vaccination are warranted....

  3. Containing pandemic influenza with antiviral agents.

    Science.gov (United States)

    Longini, Ira M; Halloran, M Elizabeth; Nizam, Azhar; Yang, Yang

    2004-04-01

    For the first wave of pandemic influenza or a bioterrorist influenza attack, antiviral agents would be one of the few options to contain the epidemic in the United States until adequate supplies of vaccine were available. The authors use stochastic epidemic simulations to investigate the effectiveness of targeted antiviral prophylaxis to contain influenza. In this strategy, close contacts of suspected index influenza cases take antiviral agents prophylactically. The authors compare targeted antiviral prophylaxis with vaccination strategies. They model an influenza pandemic or bioterrorist attack for an agent similar to influenza A virus (H2N2) that caused the Asian influenza pandemic of 1957-1958. In the absence of intervention, the model predicts an influenza illness attack rate of 33% of the population (95% confidence interval (CI): 30, 37) and an influenza death rate of 0.58 deaths/1,000 persons (95% Cl: 0.4, 0.8). With the use of targeted antiviral prophylaxis, if 80% of the exposed persons maintained prophylaxis for up to 8 weeks, the epidemic would be contained, and the model predicts a reduction to an illness attack rate of 2% (95% Cl: 0.2, 16) and a death rate of 0.04 deaths/1,000 persons (95% CI: 0.0003, 0.25). Such antiviral prophylaxis is nearly as effective as vaccinating 80% of the population. Vaccinating 80% of the children aged less than 19 years is almost as effective as vaccinating 80% of the population. Targeted antiviral prophylaxis has potential as an effective measure for containing influenza until adequate quantities of vaccine are available.

  4. Current Approaches for Diagnosis of Influenza Virus Infections in Humans

    Directory of Open Access Journals (Sweden)

    Sai Vikram Vemula

    2016-04-01

    Full Text Available Despite significant advancement in vaccine and virus research, influenza continues to be a major public health concern. Each year in the United States of America, influenza viruses are responsible for seasonal epidemics resulting in over 200,000 hospitalizations and 30,000–50,000 deaths. Accurate and early diagnosis of influenza viral infections are critical for rapid initiation of antiviral therapy to reduce influenza related morbidity and mortality both during seasonal epidemics and pandemics. Several different approaches are currently available for diagnosis of influenza infections in humans. These include viral isolation in cell culture, immunofluorescence assays, nucleic acid amplification tests, immunochromatography-based rapid diagnostic tests, etc. Newer diagnostic approaches are being developed to overcome the limitations associated with some of the conventional detection methods. This review discusses diagnostic approaches currently available for detection of influenza viruses in humans.

  5. Scenario-ontwikkeling zorgvraag bij een influenza-pandemie

    NARCIS (Netherlands)

    Genugten MLL van; Heijnen MLA; Jager JC; CZO; CIE

    2001-01-01

    Another influenza pandemic, following the 1918, 1957 and the 1968 pandemic, is likely if not inevitable. In a 'regular' influenza-epidemic 5-20% of the population is to become clinically ill; during a pandemic this percentage can mount to 30 or even 50%. A pandemic could cause substantial social dis

  6. Vaccination strategies against influenza.

    Science.gov (United States)

    Hanon, E

    2009-01-01

    Every year, Influenza virus infection is at the origin of substantial excess in morbidity and mortality in developed as well as developing countries. Influenza viruses undergo antigenic drift which cause annual replacement of strain included in classical trivalent vaccines. Less frequently, this virus can also undergo antigenic shift, which corresponds to a major antigenic change and can lead to an extra medical burden. Several vaccines have been made available to immunize individuals against seasonal as well as pandemic influenza viruses. For seasonal Influenza vaccines, live attenuated and classical inactivated trivalent vaccines have been licensed and are widely used. Additionally, several strategies are under investigations to improve further the efficacy of existing seasonal vaccines in children and elderly. These include the use of adjuvant, increase in antigen content, or alternative route of delivery. Similarly, several approaches have been licensed to address additional challenge posed by pandemic viruses. The different vaccination strategies used to maximise protection against seasonal as well as pandemic influenza will be reviewed and discussed in the perspective the current threat posed by the H1N1v pandemic Influenza.

  7. Influenza: A current medical problem

    Directory of Open Access Journals (Sweden)

    Bojić Ivanko

    2007-01-01

    Full Text Available Introduction. Acute respiratory infections are the most common infections in the human population. Among them, virus infections, especially those caused by influenza viruses, have an important place. Type A influenza. Type A influenza virus caused three epidemics during the last century. A high percetage of deceased in pandemics of 1918, and 1919 were young, healthy persons, with many of the deaths due to an unusually severe, hemorrhagic pneumonia. At the end of 2003, and the beginning of 2004, an epidemic emerged in South East Asia of poultry influenza caused by animal (avian virus. Later it spread to the human population, with a high death rate of 73% and with a possibility of interhuman transmission. This review article provides an overview of the clinical manifestations, laboratory findings and chest radiographs. Apart from the symptomatic and supportive therapy, there are antiviral drugs and corticosteriods. Conclusion. The use of vaccine containing subtypes of virus hemagglutinins and neuraminidase from an influenza virus currently infecting the population has a great importance. .

  8. Adjuvants and immunization strategies to induce influenza virus hemagglutinin stalk antibodies.

    Directory of Open Access Journals (Sweden)

    Peter H Goff

    Full Text Available The global population remains vulnerable in the face of the next pandemic influenza virus outbreak, and reformulated vaccinations are administered annually to manage seasonal epidemics. Therefore, development of a new generation of vaccines is needed to generate broad and persistent immunity to influenza viruses. Here, we describe three adjuvants that enhance the induction of stalk-directed antibodies against heterologous and heterosubtypic influenza viruses when administered with chimeric HA proteins. Addavax, an MF59-like nanoemulsion, poly(I:C, and an RNA hairpin derived from Sendai virus (SeV Cantell were efficacious intramuscularly. The SeV RNA and poly(I:C also proved to be effective respiratory mucosal adjuvants. Although the quantity and quality of antibodies induced by the adjuvants varied, immunized mice demonstrated comparable levels of protection against challenge with influenza A viruses on the basis of HA stalk reactivity. Finally, we present that intranasally, but not intramuscularly, administered chimeric HA proteins induce mucosal IgA antibodies directed at the HA stalk.

  9. The Activity of Influenza and Influenza-like Viruses in Individuals Aged over 14 in the 2015/2016 Influenza Season in Poland.

    Science.gov (United States)

    Kowalczyk, D; Cieślak, K; Szymański, K; Brydak, L B

    2017-02-15

    Infections in every epidemic season induced by respiratory viruses, especially by the influenza virus, are the cause of many illnesses and complications which often end in death. The aim of this study was to determine the activity of influenza and influenza-like viruses in individuals aged over of 14 in Poland during the 2015/2016 epidemic season. A total of 5070 specimens taken from patients were analyzed. The presence of the influenza virus was confirmed in 40.2% of cases, among which the subtype A/H1N1/pdm09 (62.6% positive samples) predominated. The analysis of confirmed influenza and influenza-like viruses in individuals divided into four age-groups demonstrate that the highest morbidity was reported for the age ranges: 45-64 (13.1%) and 26-44 (12.6%) years. An increase in the number of influenza type B cases (23.7% positive samples), which was the main cause of morbidity in the age group 15-25 years, was noticeable. Given the epidemiological and virological data, the 2015/2016 season in Poland was characterized by increased activity of the influenza virus compared to the previous season. In the 2015/2016 season, there were more than 3.8 million cases and suspected cases of influenza and influenza-like illness, more than 15,000 hospitalizations, and up to 140 deaths.

  10. Information Spreading in Epidemics and in Communication Networks

    DEFF Research Database (Denmark)

    Uekermann, Florian Philipp

    The PhD thesis revolves mainly around models of disease spreading and human behavior. We present models for different epidemic patterns of infectious diseases. This includes investigations of the trajectory of the 2014 Ebola outbreak in West-Africa, influenza evolution and the seasonal dynamics o...

  11. [Ethical principles of management and planning during influenza pandemic].

    Science.gov (United States)

    Kubar', O I; Asatrian, A Zh

    2012-01-01

    The article is dedicated to an actual problem of ethical component inclusion into the system of management and planning of epidemic control measures during threat emergence and in the course of influenza pandemic (epidemic) progress. Data regarding development of international ethical guidelines during influenza including WHO recommendations are presented and analysis of normative documents in Russian Federation is given. A necessity of comprehension and accounting of ethical values in pandemic preparedness is shown, main directions of action and responsibility are revealed. Key ethical positions of planning and implementation of measures during influenza pandemic are outlined, compliance with those determines the level of public support and thus provides the effectiveness of the implemented measures.

  12. Trends of influenza infection in Suriname.

    Science.gov (United States)

    Adhin, Malti R; Grunberg, Meritha; Labadie-Bracho, Mergiory

    2013-09-01

    The trends of influenza infection in Suriname were assessed from February 2010 through February 2011. Testing of 393 patients with symptoms of acute respiratory infection (ARI) revealed 15.3% Influenza B and 18.6% could be identified as influenza A positive, consisting of 56% influenza A(H1N1)pdm09 and 44% seasonal A(H3N2). Influenza infection occurred throughout the year, and all three influenza types affected young children as the primary population. The annual incidence of A(H1N1)pdm09 was 6.88 per 100,000 inhabitants [CI] 4.87-9.45. The spread of influenza could neither be linked to tourist flow from the Netherlands nor to contact rates related to school schedules.

  13. Pandemic Influenza: A Never-Ending Story

    Science.gov (United States)

    Kageyama, Seiji

    2011-01-01

    A novel pandemic influenza emerged in 2009, something that hasn't been seen since 1977. The following issues will be introduced and discussed in this review: the history of influenza pandemics, the emergence of the novel pandemic influenza of 2009, epidemics in the southern and northern hemispheres after the recognition of index cases in the United States, mortality, viral characteristics, prevention in the household setting, clinical aspects, diagnosis, treatment and immunization. Some questions have been answered. However, a number of other questions remain. Scientific research must follow up on these unanswered questions. PMID:24031128

  14. Early estimates of 2014/15 seasonal influenza vaccine effectiveness in preventing influenza-like illness in general practice using the screening method in France.

    Science.gov (United States)

    Souty, Cécile; Blanchon, Thierry; Bonmarin, Isabelle; Lévy-Bruhl, Daniel; Behillil, Sylvie; Enouf, Vincent; Valette, Martine; Bouscambert, Maude; Turbelin, Clément; Capai, Lisandru; Roussel, Victoire; Hanslik, Thomas; Falchi, Alessandra

    2015-01-01

    The ongoing influenza epidemic is characterized by intense activity with most influenza infections due to the A (H3N2) viruses. Using the screening method, mid-season vaccine effectiveness (VE) in preventing influenza-like illness in primary care was estimated to 32% (95% CI; 23 to 40) among risk groups and was 11% (95% CI; -4 to 23) among the elderly (≥ 65 y). The VE in ≥ 65 y was the lowest estimate regarding the 4 previous seasonal influenza epidemics.

  15. DEVELOPMENT OF TEST KIT FOR DETECTION OF PANDEMIC STRAIN INFLUENZA VIRUS A (H1N1 2009 BY REAL TIME POLYMERASE CHAIN REACTION

    Directory of Open Access Journals (Sweden)

    S. V. Stepaniuk

    2013-04-01

    Full Text Available Influenza viruses A play an important role in the structure of the incidence of people with acute respiratory viral infection, which make up 90% from all other infectious diseases. According to the World Health Organization, only severe flu worldwide suffer annually 3.5 million, of which 45–60% are children. An economic loss from seasonal flu epidemic is in average about 85% of economic losses from infectious diseases in general. The experience of fighting the flu, accumulated over the years, has shown that to develop and deliver effective preventive measures necessary to build a system of permanent monitoring for influenza virus circulation, based on use of laboratory methods for accurate and rapid dentification and characterization of circulating strains of influenza virus A. Among the methods of laboratory diagnosis of influenza, the most effective is a method of polymerase chain reaction. Data on the evelopment of diagnostic test kits in the format of two-stage multiplex RTPCR-analysis for detection and genotyping of pandemic influenza virus A (H1N12009 are given. The results of laboratory and experimental research of «DIA Influenza H1N1» test system showed that it is effective and specific for detection of California pandemic influenza virus A (H1N12009 strains and can be used to diagnose disease caused by this strain of virus. Clinical trial of the course of the State registration by Ministry of Health of Ukraine have shown sensitivity and specificity of «DIA Influenza H1N1» test systems up to 100%.

  16. Meningitis - H. influenzae

    Science.gov (United States)

    H. influenzae meningitis; H. flu meningitis; Haemophilus influenzae type b meningitis ... H. influenzae meningitis is caused by Haemophilus influenzae type b bacteria. This illness is not the same as the flu ( influenza ), ...

  17. NNDSS - Table II. Giardiasis to Haemophilus influenza

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Giardiasis to Haemophilus influenza - 2014. In this Table, all conditions with a 5-year average annual national total of more than or equals 1,000...

  18. [Human influenza].

    Science.gov (United States)

    Stock, Ingo

    2006-10-01

    Human influenza is one of the most common human infectious diseases, contributing to approximately one million deaths every year. In Germany, each year between 5.000 and 20.000 individuals die from severe influenza infections. In several countries, the morbidity and mortality of influenza is greatly underestimated. This is reflected by general low immunization rates. The emergence of avian influenza against the background of the scenario of a human influenza pandemic has revived public interest in the disease. According to the World Health Organisation, it is only the question on the beginning of a new influenza pandemic. The virus type of the new pandemic is still uncertain and it is also unclear, if a pandemic spread of the virus may be prevented by consistent controlling of avian influenza.

  19. Influenza and pneumococcal vaccination of the elderly in Taiwan.

    Science.gov (United States)

    Chen, Yeong-Hwang; Liou, Saou-Hsing; Chou, Chih-Chieh; Su, Wen-Lin; Loh, Ching-Hui; Lin, Shih-Ha

    2004-07-29

    In 1998, Taiwan became the first country in Asia to provide free influenza vaccination to high-risk groups, mainly the elderly. The purpose of this study is to determine: (1) the annual mortality rate from influenza and pneumococcal-related illnesses such as pneumonia, chronic bronchitis, pulmonary emphysema and asthma and (2) the effectiveness of and adverse events associated with the influenza vaccination. In the elderly, influenza vaccination caused the annual death rate due chronic bronchitis, pulmonary emphysema, and asthma to decline steadily but had no effect on the annual pneumonia death rate. The only adverse effect of concern was vertigo (in approximately 2-3%).

  20. Influenza in Thailand: a case study for middle income countries.

    Science.gov (United States)

    Simmerman, James Mark; Thawatsupha, Pranee; Kingnate, Darika; Fukuda, Keiji; Chaising, Arunee; Dowell, Scott F

    2004-11-25

    Recent studies in Hong Kong and Singapore suggest that the annual impact of influenza in these wealthy tropical cities may be substantial, but little is known about the burden in middle-income tropical countries. We reviewed the status of influenza surveillance, vaccination, research, and policy in Thailand as of January 2004. From 1993 to 2002, 64-91 cases of clinically diagnosed influenza were reported per 100,000 persons per year. Influenza viruses were isolated in 34% of 4305 specimens submitted to the national influenza laboratory. Vaccine distribution figures suggest that less than 1% of the population is immunized against influenza each year. In January 2004, Thailand reported its first documented outbreak of influenza A H5N1 infection in poultry and the country's first human cases of avian influenza. Thailand's growing economy, well-developed public health infrastructure, and effective national immunization program could enable the country to take more active steps towards influenza control.

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

    Science.gov (United States)

    Lee, Paul J; Krilov, Leonard R

    2005-01-01

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

  2. [Avian influenza and oseltamivir; a retrospective view

    NARCIS (Netherlands)

    Galama, J.M.D.

    2003-01-01

    The outbreak of avian influenza A due to an H7N7 virus in Dutch poultry farms turned out to have public-health effects for those who were involved in the management of the epidemic and who were thus extensively exposed to contaminated excreta and dust. An outbreak-management team (OMT) of experts in

  3. Patient-based transcriptome-wide analysis identify interferon and ubiquination pathways as potential predictors of influenza A disease severity.

    Directory of Open Access Journals (Sweden)

    Long Truong Hoang

    Full Text Available The influenza A virus is an RNA virus that is responsible for seasonal epidemics worldwide with up to five million cases of severe illness and 500,000 deaths annually according to the World Health Organization estimates. The factors associated with severe diseases are not well defined, but more severe disease is more often seen among persons aged >65 years, infants, pregnant women, and individuals of any age with underlying health conditions.Using gene expression microarrays, the transcriptomic profiles of influenza-infected patients with severe (N = 11, moderate (N = 40 and mild (N = 83 symptoms were compared with the febrile patients of unknown etiology (N = 73. We found that influenza-infected patients, regardless of their clinical outcomes, had a stronger induction of antiviral and cytokine responses and a stronger attenuation of NK and T cell responses in comparison with those with unknown etiology. More importantly, we found that both interferon and ubiquitination signaling were strongly attenuated in patients with the most severe outcomes in comparison with those with moderate and mild outcomes, suggesting the protective roles of these pathways in disease pathogenesis.The attenuation of interferon and ubiquitination pathways may associate with the clinical outcomes of influenza patients.

  4. Influenza Vaccine Research funded by the European Commission FP7-Health-2013-Innovation-1 project

    NARCIS (Netherlands)

    Liu, Heng; Frijlink, Henderik W.; Huckriede, Anke; van Doorn, Eva; Schmidt, Ed; Leroy, Odile; Rimmelzwaan, Guus; McCullough, Keneth; Whelan, Mike; Hak, Eelko

    2016-01-01

    Due to influenza viruses continuously displaying antigenic variation, current seasonal influenza vaccines must be updated annually to include the latest predicted strains. Despite all the efforts put into vaccine strain selection, vaccine production, testing, and administration, the protective effic

  5. [Epidemics and disease during the Revolution Period in Mexico].

    Science.gov (United States)

    Sanfilippo-Borrás, José

    2010-01-01

    The health condition in Mexico was bad around de beginning of the revolutionary period. The movement of troops led the development of epidemics like yellow fever, typhus, smallpox, and influenza that were enhance with natural disasters and hunger in whole country, from cost to cost and in the north big cities like Monterrey, Guadalajara and Saltillo. Doctor Liceaga conducted a well planned campaign against yellow fever eradicating water stagnant deposits in order to combat the vector transmission, the Aedes aegypti, mosquito with satisfactory results. The first smallpox epidemic in the XX Century in Mexico was in 1916. The Mexican physicians used the smallpox vaccine against this epidemic. An American physician named Howard Taylor Ricketts arrived to Mexico for studying the typhus transmission. Accidentally he had been infected and finally, he died from typhus. Definitively, the epidemics predominate along de revolutionary period in Mexico.

  6. Emergency Physicians’ Adherence to Center for Disease Control and Prevention Guidance During the 2009 Influenza A H1N1 Pandemic

    Directory of Open Access Journals (Sweden)

    Yu-Hsiang Hsieh

    2013-03-01

    Full Text Available Introduction: Little is known regarding compliance with management guidelines for epidemicinfluenza in adult emergency department (ED settings during the 2009 novel influenza A(H1N1 epidemic, especially in relation to the Centers for Disease Control and Prevention (CDCguidance.Methods: We investigated all patients with a clinical diagnosis of influenza at an inner-citytertiary academic adult ED with an annual census of approximately 60,000 visits from May 2008to December 2009. We aimed to determine patterns of presentation and management for adultpatients with an ED diagnosis of influenza during the H1N1 pandemic, using seasonal influenza(pre-H1N1 as reference and to determine the ED provider’s adherence to American College ofEmergency Physicians and CDC guidance during the 2009 H1N1 influenza pandemic. Adherenceto key elements of CDC 2009 H1N1 guidance was defined as (1 the proportion of admittedpatients who were recommended to receive testing or treatment who actually received testingfor influenza or treatment with antivirals; and (2 the proportion of high-risk patients who weresupposed to be treated who actually were treated with antivirals.Results: Among 339 patients with clinically diagnosed influenza, 88% occurred during the H1N1pandemic. Patients were similarly managed during both phases. Median length of visit (pre-H1N1:385 min, H1N1: 355 min, P > 0.05 and admission rates (pre-H1N1: 8%, H1N1: 11%, P > 0.05were similar between the 2 groups. 28% of patients in the pre-H1N1 group and 16% of patientsin the H1N1 group were prescribed antibiotics during their ED visits (P > 0.05. There were 34admitted patients during the pandemic;, 30 (88% of them received influenza testing in the ED,and 22 (65% were prescribed antivirals in the ED. Noticeably, 19 (56% of the 34 admittedpatients, including 6 with a positive influenza test, received antibiotic treatment during their ED stay.Conclusion: During the recent H1N1 pandemic, most admitted patients

  7. 3DFlu: database of sequence and structural variability of the influenza hemagglutinin at population scale

    Science.gov (United States)

    Mazzocco, Giovanni; Lazniewski, Michal; Migdał, Piotr; Szczepińska, Teresa; Radomski, Jan P.; Plewczynski, Dariusz

    2016-01-01

    The influenza virus type A (IVA) is an important pathogen which is able to cause annual epidemics and even pandemics. This fact is the consequence of the antigenic shifts and drifts capabilities of IVA, caused by the high mutation rate and the reassortment capabilities of the virus. The hemagglutinin (HA) protein constitutes the main IVA antigen and has a crucial role in the infection mechanism, being responsible for the recognition of host-specific sialic acid derivatives. Despite the relative abundance of HA sequence and serological studies, comparative structure-based analysis of HA are less investigated. The 3DFlu database contains well annotated HA representatives: 1192 models and 263 crystallographic structures. The relations between these proteins are defined using different metrics and are visualized as a network in the provided web interface. Moreover structural and sequence comparison of the proteins can be explored. Metadata information (e.g. protein identifier, IVA strain, year and location of infection) can enhance the exploration of the presented data. With our database researchers gain a useful tool for the exploration of high quality HA models, viewing and comparing changes in the HA viral subtypes at several information levels (sequence, structure, ESP). The complete and integrated view of those relations might be useful to determine the efficiency of transmission, pathogenicity and for the investigation of evolutionary tendencies of the influenza virus. Database URL: http://nucleus3d.cent.uw.edu.pl/influenza PMID:27694207

  8. Usage of quadrivalent influenza vaccine among children in the United States, 2013-14.

    Science.gov (United States)

    Rodgers, Loren; Pabst, Laura J; Zhu, Liping; Chaves, Sandra S

    2015-11-27

    Annual influenza vaccination is recommended for everyone ≥ 6 months in the U.S. During the 2013-14 influenza season, in addition to trivalent influenza vaccines, quadrivalent vaccines were available, protecting against two influenza A and two influenza B viruses. We analyzed 1,976,443 immunization records from six sentinel sites to compare influenza vaccine usage among children age 6 months-18 years. A total of 983,401 (49.8%) influenza vaccine doses administered were trivalent and 920,333 (46.6%) were quadrivalent (unknown type: 72,709). Quadrivalent vaccine administration varied by age and was least frequent among those <2 years of age.

  9. Modeling Epidemic Network Failures

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Fagertun, Anna Manolova

    2013-01-01

    This paper presents the implementation of a failure propagation model for transport networks when multiple failures occur resulting in an epidemic. We model the Susceptible Infected Disabled (SID) epidemic model and validate it by comparing it to analytical solutions. Furthermore, we evaluate...... the SID model’s behavior and impact on the network performance, as well as the severity of the infection spreading. The simulations are carried out in OPNET Modeler. The model provides an important input to epidemic connection recovery mechanisms, and can due to its flexibility and versatility be used...... to evaluate multiple epidemic scenarios in various network types....

  10. In Vitro Antiviral Effect of "Nanosilver" on Influenza Virus

    Directory of Open Access Journals (Sweden)

    P Mehrbod

    2009-08-01

    Full Text Available Introduction: Influenza is a viral infectious disease with frequent seasonal epidemics causing world-wide economical and social effects. Due to antigenic shifts and drifts of influenza virus, long-lasting vaccine has not been developed so far. The current annual vaccines and effective antiviral drugs are not available sufficiently. Therefore in order to prevent spread of infectious agents including viruses, antiseptics are considered by world health authorities. Small particles of silver have a long history as general antiseptic and disinfectant. Silver does not induce resistance in microorganisms and this ability in Nano-size is stronger. Materials and methods: The aim of this study was to determine antiviral effects of Nanosilver against influenza virus. TCID50 (50% Tissue Culture Infectious Dose of the virus as well as CC50 (50% Cytotoxic Concentration of Nanosilver was obtained by MTT (3- [4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl-tetrazolium bromide, Sigma method. This compound was non-toxic to MDCK (Madin-Darbey Canin Kidney cells at concentration up to 1 µg/ml.  Effective minimal cytotoxic concentration and 100 TCID50 of the virus were added to the confluent cells.  Inhibitory effects of Nanosilver on the virus and its cytotoxicity were assessed at different temperatures using Hemagglutination (HA assay, RT-PCR (Reverse Transcriptase-Polymerase Chain Reaction, and DIF (Direct Immunofluorescent. RT-PCR and free band densitometry software were used to compare the volume of the PCR product bands on the gel. Results and Discussion:  In this study it was found that Nanosilver has destructive effect on the virus membrane glycoprotein knobs as well as the cells.

  11. Detecting nonlinearity and chaos in epidemic data

    Energy Technology Data Exchange (ETDEWEB)

    Ellner, S.; Gallant, A.R. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Statistics; Theiler, J. [Santa Fe Inst., NM (United States)]|[Los Alamos National Lab., NM (United States)

    1993-08-01

    Historical data on recurrent epidemics have been central to the debate about the prevalence of chaos in biological population dynamics. Schaffer and Kot who first recognized that the abundance and accuracy of disease incidence data opened the door to applying a range of methods for detecting chaos that had been devised in the early 1980`s. Using attractor reconstruction, estimates of dynamical invariants, and comparisons between data and simulation of SEIR models, the ``case for chaos in childhood epidemics`` was made through a series of influential papers beginning in the mid 1980`s. The proposition that the precise timing and magnitude of epidemic outbreaks are deterministic but chaotic is appealing, since it raises the hope of finding determinism and simplicity beneath the apparently stochastic and complicated surface of the data. The initial enthusiasm for methods of detecting chaos in data has been followed by critical re-evaluations of their limitations. Early hopes of a ``one size fits all`` algorithm to diagnose chaos vs. noise in any data set have given way to a recognition that a variety of methods must be used, and interpretation of results must take into account the limitations of each method and the imperfections of the data. Our goals here are to outline some newer methods for detecting nonlinearity and chaos that have a solid statistical basis and are suited to epidemic data, and to begin a re-evaluation of the claims for nonlinear dynamics and chaos in epidemics using these newer methods. We also identify features of epidemic data that create problems for the older, better known methods of detecting chaos. When we ask ``are epidemics nonlinear?``, we are not questioning the existence of global nonlinearities in epidemic dynamics, such as nonlinear transmission rates. Our question is whether the data`s deviations from an annual cyclic trend (which would reflect global nonlinearities) are described by a linear, noise-driven stochastic process.

  12. Uptake of the Influenza Vaccination in Pregnancy

    LENUS (Irish Health Repository)

    Crosby, DA

    2016-09-01

    Influenza is caused by a highly infectious RNA virus, which usually occurs in a seasonal pattern with epidemics in the winter months. The objective of this study was to determine the uptake of the influenza vaccine in a pregnant population and ascertain the reasons why some women did not receive it. A prospective cohort study was conducted over a two-week period in January 2016 in the National Maternity Hospital Dublin, a tertiary referral maternity hospital delivering over 9000 infants per year. There were 504 women studied over the 2-week period. Overall, 197(39.1%) women received the vaccine at a mean gestational age 20.9 weeks (SD 7.0). Given the increased rates of influenza in the community and the associated implications for mother and infant, it is important that pregnant women are educated regarding the risks of influenza in pregnancy and encourage this cohort to be vaccinated.

  13. Clinical prediction rules combining signs, symptoms and epidemiological context to distinguish influenza from influenza-like illnesses in primary care: a cross sectional study

    Directory of Open Access Journals (Sweden)

    Van Royen Paul

    2011-02-01

    Full Text Available Abstract Background During an influenza epidemic prompt diagnosis of influenza is important. This diagnosis however is still essentially based on the interpretation of symptoms and signs by general practitioners. No single symptom is specific enough to be useful in differentiating influenza from other respiratory infections. Our objective is to formulate prediction rules for the diagnosis of influenza with the best diagnostic performance, combining symptoms, signs and context among patients with influenza-like illness. Methods During five consecutive winter periods (2002-2007 138 sentinel general practitioners sampled (naso- and oropharyngeal swabs 4597 patients with an influenza-like illness (ILI and registered their symptoms and signs, general characteristics and contextual information. The samples were analysed by a DirectigenFlu-A&B and RT-PCR tests. 4584 records were useful for further analysis. Starting from the most relevant variables in a Generalized Estimating Equations (GEE model, we calculated the area under the Receiver Operating Characteristic curve (ROC AUC, sensitivity, specificity and likelihood ratios for positive (LR+ and negative test results (LR- of single and combined signs, symptoms and context taking into account pre-test and post-test odds. Results In total 52.6% (2409/4584 of the samples were positive for influenza virus: 64% (2066/3212 during and 25% (343/1372 pre/post an influenza epidemic. During and pre/post an influenza epidemic the LR+ of 'previous flu-like contacts', 'coughing', 'expectoration on the first day of illness' and 'body temperature above 37.8°C' is 3.35 (95%CI 2.67-4.03 and 1.34 (95%CI 0.97-1.72, respectively. During and pre/post an influenza epidemic the LR- of 'coughing' and 'a body temperature above 37.8°C' is 0.34 (95%CI 0.27-0.41 and 0.07 (95%CI 0.05-0.08, respectively. Conclusions Ruling out influenza using clinical and contextual information is easier than ruling it in. Outside an influenza

  14. Predicting pneumonia and influenza mortality from morbidity data.

    Directory of Open Access Journals (Sweden)

    Lise Denoeud

    Full Text Available BACKGROUND: Few European countries conduct reactive surveillance of influenza mortality, whereas most monitor morbidity. METHODOLOGY/PRINCIPAL FINDINGS: We developed a simple model based on Poisson seasonal regression to predict excess cases of pneumonia and influenza mortality during influenza epidemics, based on influenza morbidity data and the dominant types/subtypes of circulating viruses. Epidemics were classified in three levels of mortality burden ("high", "moderate" and "low". The model was fitted on 14 influenza seasons and was validated on six subsequent influenza seasons. Five out of the six seasons in the validation set were correctly classified. The average absolute difference between observed and predicted mortality was 2.8 per 100,000 (18% of the average excess mortality and Spearman's rank correlation coefficient was 0.89 (P = 0.05. CONCLUSIONS/SIGNIFICANCE: The method described here can be used to estimate the influenza mortality burden in countries where specific pneumonia and influenza mortality surveillance data are not available.

  15. 河北省甲3亚型流感病毒流行株对金刚烷胺耐药性分析%Analysis of the resistance to amantadine of epidemic strain of influenza A (H3N2) viruses isolated from Hebei

    Institute of Scientific and Technical Information of China (English)

    刘艳芳; 韩光跃; 刘兰芬; 李岩; 张建芳; 齐顺祥

    2011-01-01

    Objective To analyze the resistance to amantadine of epidemic strain of influenza A(H3N2) viruses isolated from Hebei during 2004 - 2008, and to provide reference for the clinical usage of amantadine drugs. Methods 136 strains of influenza A(H3N2) virus were selected from Hebei surveillance network, viral RNAs were extracted and their M2 gene segments were amplified by reverse transcription polymerase chain reaction (RT-PCR). The purified PCR products were sequenced. The positions of amino acid for resistance to amantadine were analyzed though biometic software. Results Of the 136 strains of influenza A(H3N2) virus, 128 strains had amino acid changes at the tanmembrane domain of the M2 protein, the resistant percentage to amantadine was 94.12 %. Of the 128 amantadine-resistant strains, 3(2.34 % ) strains had single amino acid changes at V27A site, 125 (97.66 % ) strains had replacement at S31 N. And in these 125 strains, 5 (4.00 % ) strairs had the replacement at V271 and S31 N site, and 3 (2.40 % ) strains contained the replacement at A29T and S31N site simultaneously. During 2004 - 2008 influenza season, the percentage of resistance to amantadine was 78.95 % ( 30/38), 100.00 % (2/2 ), 100.00 % ( 89/89 ) and 100.00 % (7/7 ) respectively. Conclusions 100 % of virus among the epidemic strains isolated showed amantadine resistance during 2005 - 2006 influenza season, our results indicated that amantadine should not be used for the treatment and prophylaxis of influenza.%目的 分析河北省2004-2008年流感流行期甲3亚型流感病毒流行株对金刚烷胺的耐药情况,为流感的临床治疗用药提供科学依据.方法 选取河北省流感监测实验室分离的136株甲3亚型流感病毒,提取病毒核酸,采用RT-PCR扩增流感病毒M2基因片段,纯化产物进行核苷酸序列测定,用生物信息软件分析其与耐药有关的氨基酸位点.结果 136株甲3亚型流感病毒分离株中,128株M2蛋白跨膜区耐

  16. Increasing herd immunity with influenza revaccination.

    Science.gov (United States)

    Mooring, E Q; Bansal, S

    2016-04-01

    Seasonal influenza is a significant public health concern globally. While influenza vaccines are the single most effective intervention to reduce influenza morbidity and mortality, there is considerable debate surrounding the merits and consequences of repeated seasonal vaccination. Here, we describe a two-season influenza epidemic contact network model and use it to demonstrate that increasing the level of continuity in vaccination across seasons reduces the burden on public health. We show that revaccination reduces the influenza attack rate not only because it reduces the overall number of susceptible individuals, but also because it better protects highly connected individuals, who would otherwise make a disproportionately large contribution to influenza transmission. We also demonstrate that our results hold on an empirical contact network, in the presence of assortativity in vaccination status, and are robust for a range of vaccine coverage and efficacy levels. Our work contributes a population-level perspective to debates about the merits of repeated influenza vaccination and advocates for public health policy to incorporate individual vaccine histories.

  17. Guiding outbreak management by the use of influenza A(H7Nx) virus sequence analysis

    NARCIS (Netherlands)

    Jonges, M.; Meijer, A.; Fouchier, R.A.M.; Koch, G.; Li, J.; Pan, J.C.; Shu, Y.L.; Koopmans, M.P.G.; Chen, H.

    2013-01-01

    The recently identified human infections with avian influenza A(H7N9) viruses in China raise important questions regarding possible source and risk to humans. Sequence comparison with an influenza A(H7N7) outbreak in the Netherlands in 2003 and an A(H7N1) epidemic in Italy in 1999–2000 suggests that

  18. Guiding outbreak management by the use of influenza a(H7NX) virus sequence analysis

    NARCIS (Netherlands)

    M. Jonges (Marcel); A. Meijer (Adam); R.A.M. Fouchier (Ron); G. Koch (Guus); J. Li; J.C. Pan; H. Chen (Hong); Y.L. Shu (Yue-Long); M.P.G. Koopmans D.V.M. (Marion)

    2013-01-01

    textabstractThe recently identified human infections with avian influenza A(H7N9) viruses in China raise important questions regarding possible source and risk to humans. Sequence comparison with an influenza A(H7N7) outbreak in the Netherlands in 2003 and an A(H7N1) epidemic in Italy in 1999-2000 s

  19. Antiviral Effect of Methylated Flavonol Isorhamnetin against Influenza

    OpenAIRE

    Ahmed Abdal Dayem; Hye Yeon Choi; Young Bong Kim; Ssang-Goo Cho

    2015-01-01

    Influenza is an infectious respiratory disease with frequent seasonal epidemics that causes a high rate of mortality and morbidity in humans, poultry, and animals. Influenza is a serious economic concern due to the costly countermeasures it necessitates. In this study, we compared the antiviral activities of several flavonols and other flavonoids with similar, but distinct, hydroxyl or methyl substitution patterns at the 3, 3', and 4' positions of the 15-carbon flavonoid skeleton, and found t...

  20. Where and When Human Viral Epidemics First Emerged

    OpenAIRE

    Rumyantsev, Sergey N.

    2012-01-01

    Aims: This article attempts to date the conditions, terms and places of the first emergence of the main human viral epidemics (HIV, influenza, measles, smallpox). Place and Duration of Study: Department of Evolutionary Immunology Andent, Inc., between May 2002 and July 2012. Methodology: The investigation was based on the integration and consequent sensing of relevant recent achievements of evolutionary branches of immunology, epidemiology and anthropology. The main focus was on the integrati...

  1. Health newscasts for increasing influenza vaccination coverage: an inductive reasoning game approach.

    Directory of Open Access Journals (Sweden)

    Romulus Breban

    Full Text Available Both pandemic and seasonal influenza are receiving more attention from mass media than ever before. Topics such as epidemic severity and vaccination are changing the way in which we perceive the utility of disease prevention. Voluntary influenza vaccination has been recently modeled using inductive reasoning games. It has thus been found that severe epidemics may occur because individuals do not vaccinate and, instead, attempt to benefit from the immunity of their peers. Such epidemics could be prevented by voluntary vaccination if incentives were offered. However, a key assumption has been that individuals make vaccination decisions based on whether there was an epidemic each influenza season; no other epidemiological information is available to them. In this work, we relax this assumption and investigate the consequences of making more informed vaccination decisions while no incentives are offered. We obtain three major results. First, individuals will not cooperate enough to constantly prevent influenza epidemics through voluntary vaccination no matter how much they learned about influenza epidemiology. Second, broadcasting epidemiological information richer than whether an epidemic occurred may stabilize the vaccination coverage and suppress severe influenza epidemics. Third, the stable vaccination coverage follows the trend of the perceived benefit of vaccination. However, increasing the amount of epidemiological information released to the public may either increase or decrease the perceived benefit of vaccination. We discuss three scenarios where individuals know, in addition to whether there was an epidemic, (i the incidence, (ii the vaccination coverage and (iii both the incidence and the vaccination coverage, every influenza season. We show that broadcasting both the incidence and the vaccination coverage could yield either better or worse vaccination coverage than broadcasting each piece of information on its own.

  2. Health newscasts for increasing influenza vaccination coverage: an inductive reasoning game approach.

    Science.gov (United States)

    Breban, Romulus

    2011-01-01

    Both pandemic and seasonal influenza are receiving more attention from mass media than ever before. Topics such as epidemic severity and vaccination are changing the way in which we perceive the utility of disease prevention. Voluntary influenza vaccination has been recently modeled using inductive reasoning games. It has thus been found that severe epidemics may occur because individuals do not vaccinate and, instead, attempt to benefit from the immunity of their peers. Such epidemics could be prevented by voluntary vaccination if incentives were offered. However, a key assumption has been that individuals make vaccination decisions based on whether there was an epidemic each influenza season; no other epidemiological information is available to them. In this work, we relax this assumption and investigate the consequences of making more informed vaccination decisions while no incentives are offered. We obtain three major results. First, individuals will not cooperate enough to constantly prevent influenza epidemics through voluntary vaccination no matter how much they learned about influenza epidemiology. Second, broadcasting epidemiological information richer than whether an epidemic occurred may stabilize the vaccination coverage and suppress severe influenza epidemics. Third, the stable vaccination coverage follows the trend of the perceived benefit of vaccination. However, increasing the amount of epidemiological information released to the public may either increase or decrease the perceived benefit of vaccination. We discuss three scenarios where individuals know, in addition to whether there was an epidemic, (i) the incidence, (ii) the vaccination coverage and (iii) both the incidence and the vaccination coverage, every influenza season. We show that broadcasting both the incidence and the vaccination coverage could yield either better or worse vaccination coverage than broadcasting each piece of information on its own.

  3. Epidemiological characteristics of 420 influenza A (H1N1) cases confirmed in the early stage of the epidemic in mainland China%中国大陆2009年早期确诊的420例甲型H1N1流感病例流行病学特征分析

    Institute of Scientific and Technical Information of China (English)

    李亚品; 钱全; 方立群; 杨红; 魏茂提; 高燕; 杨华; 张勇; 曹务春

    2009-01-01

    Objective To describe the epidemical characteristics of A (H1N1) influenza identified in the early stage (from May 11 to June 22, 2009) of the epidemic, in mainland China. Methods Epidemical characteristics of 420 confirmed A (H1N1) influenza cases reported from May 11 to June 22, 2009 were analyzed descriptively, including the distribution of age, sex, source of infection, main symptoms and incubation period. Results A total of 77.8% early cases in mainland China were imported from other countries. Three countries including America, Canada and Australia were attributed to 90% of the imported cases. Most of the cases were from 6 months to 73 years old, with 94% of them under 50 years. Most of the symptoms would include fever (81%), cough (40%) and sore throat (35%). The mean incubation period of second-generation cases was 4.3 (4.2±1.5) days. Conclusion Imported cases dominated the total cases in the early stage of the epidemic had similar gender distribution of those from exporting countries. Fever, cough and sore throat were the three main symptoms manifested in influenza cases. 2.5±1.9(1-11)days was found in imported cases between the day of off-board and the onset of symptoms. The incubation period was 4.3±1.7 (1-8) days among the secondary cases.%目的 了解中国大陆2009年早期(5月11日至6月22日)确诊的甲型H1N1流感病例的流行病学特征.方法 应用描述性流行病学方法对中国大陆2009年早期确诊的420例甲型H1N1流感病例的年龄、性别、来源、主要症状、潜伏期等流行病学特征进行分析.结果 中国大陆早期诊断的甲型H1N1流感病例中输入性病例占总病例数的77.8%,主要由美国、加拿大、澳大利亚三个国家输入,占中国大陆总输入性病例的90%;所有患者中男性占53%,平均年龄22岁(22.2岁±14.9岁);早期确诊的甲型H1N1病例以发热(81%)、咳嗽(40%)、咽痛(35%)等症状为主;输入性病例从入境到发病平均2.5 d±1.9 d(1~11 d

  4. Chemical Genomics Identifies the PERK-Mediated Unfolded Protein Stress Response as a Cellular Target for Influenza Virus Inhibition

    Directory of Open Access Journals (Sweden)

    Sara Landeras-Bueno

    2016-04-01

    Full Text Available Influenza A viruses generate annual epidemics and occasional pandemics of respiratory disease with important consequences for human health and the economy. Therefore, a large effort has been devoted to the development of new anti-influenza virus drugs directed to viral targets, as well as to the identification of cellular targets amenable to anti-influenza virus therapy. Here we have addressed the identification of such potential cellular targets by screening collections of drugs approved for human use. We reasoned that screening with a green fluorescent protein-based recombinant replicon system would identify cellular targets involved in virus transcription/replication and/or gene expression and hence address an early stage of virus infection. By using such a strategy, we identified Montelukast (MK as an inhibitor of virus multiplication. MK inhibited virus gene expression but did not alter viral RNA synthesis in vitro or viral RNA accumulation in vivo. The low selectivity index of MK prevented its use as an antiviral, but it was sufficient to identify a new cellular pathway suitable for anti-influenza virus intervention. By deep sequencing of RNA isolated from mock- and virus-infected human cells, treated with MK or left untreated, we showed that it stimulates the PERK-mediated unfolded protein stress response. The phosphorylation of PERK was partly inhibited in virus-infected cells but stimulated in MK-treated cells. Accordingly, pharmacological inhibition of PERK phosphorylation led to increased viral gene expression, while inhibition of PERK phosphatase reduced viral protein synthesis. These results suggest the PERK-mediated unfolded protein response as a potential cellular target to modulate influenza virus infection.

  5. A dose-response evaluation of inactivated influenza vaccine given intranasally and intramuscularly to healthy young adults.

    Science.gov (United States)

    Atmar, Robert L; Keitel, Wendy A; Cate, Thomas R; Munoz, Flor M; Ruben, Fred; Couch, Robert B

    2007-07-20

    Epidemic influenza occurs annually throughout the world and is accompanied by excess morbidity and mortality. Increasing the antigen content and topical administration of vaccine are two strategies being explored to improve the immune responses to trivalent inactivated influenza vaccine (TIV). We conducted a randomized, double-blind, placebo-controlled trial to compare the immunogenicity and reactogenicity of intramuscular (IM), intranasal (IN), or combined IM and IN administration of a contemporary US vaccine formulation at escalating dosage levels in young healthy adults. Two hundred forty three healthy adults between the ages of 18 and 45 years received 15, 30, or 60mcg of trivalent inactivated influenza vaccine by either IN, IM or both routes, 120mcg of vaccine IM, or placebo IN and IM. All dosages and routes of vaccine administration were well-tolerated. A bad taste and mild nasal discomfort were more likely to be reported when influenza vaccine was administered IN, while arm tenderness was more common after IM administration. Significant increases in geometric mean serum antibody titers in both HAI and Nt assays were seen in all of the groups receiving influenza vaccine for all test antigens (Por=32 were higher following delivery of the study vaccines by an IM route than by the IN route, but significant increases in serum antibody were seen after IN vaccination. Nasal IgA antibody responses were more common when vaccine was administered IN; and, when the IN dosage was increased, the primary benefit from IN vaccine over IM vaccine appeared to be greater induction of nasal secretory antibody.

  6. Avian influenza

    Science.gov (United States)

    ... of avian influenza A in Asia, Africa, Europe, Indonesia, Vietnam, the Pacific, and the near East. Hundreds ... to detect abnormal breath sounds) Chest x-ray Culture from the nose or throat A method or ...

  7. Avian Influenza

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a letter from a professor at Clemson University about waterfowl that had been tested for avian influenza at Santee National Wildlife Refuge

  8. Epidemic model with isolation in multilayer networks

    CERN Document Server

    Zuzek, L G Alvarez; Braunstein, L A

    2014-01-01

    The Susceptible-Infected-Recovered (SIR) model has successfully mimicked the propagation of such airborne diseases as influenza A (H1N1). Although the SIR model has recently been studied in a multilayer networks configuration, in almost all the research the dynamic movement of infected individuals, e.g., how they are often kept in isolation, is disregarded. We study the SIR model in two multilayer networks and use an isolation parameter, indicating time period, to measure the effect of isolating infected individuals from both layers. This isolation reduces the transmission of the disease because the time in which infection can spread is reduced. In this scenario we find that the epidemic threshold increases with the isolation time and the isolation parameter and the impact of the propagation is reduced. We also find that when isolation is total there is a threshold for the isolation parameter above which the disease never becomes an epidemic. We also find that regular epidemic models always overestimate the e...

  9. Epidemic and Non-Epidemic Hot Spots of Malaria Transmission Occur in Indigenous Comarcas of Panama.

    Directory of Open Access Journals (Sweden)

    William Lainhart

    2016-05-01

    Full Text Available From 2002-2005, Panama experienced a malaria epidemic that has been associated with El Niño Southern Oscillation weather patterns, decreased funding for malaria control, and landscape modification. Case numbers quickly decreased afterward, and Panama is now in the pre-elimination stage of malaria eradication. To achieve this new goal, the characterization of epidemiological risk factors, foci of transmission, and important anopheline vectors is needed. Of the 24,681 reported cases in these analyses (2000-2014, ~62% occurred in epidemic years and ~44% in indigenous comarcas (5.9% of Panama's population. Sub-analyses comparing overall numbers of cases in epidemic and non-epidemic years identified females, comarcas and some 5-year age categories as those disproportionately affected by malaria during epidemic years. Annual parasites indices (APIs; number of cases per 1,000 persons for Plasmodium vivax were higher in comarcas compared to provinces for all study years, though P. falciparum APIs were only higher in comarcas during epidemic years. Interestingly, two comarcas report increasing numbers of cases annually, despite national annual decreases. Inclusion of these comarcas within identified foci of malaria transmission confirmed their roles in continued transmission. Comparison of species distribution models for two important anophelines with Plasmodium case distribution suggest An. albimanus is the primary malaria vector in Panama, confirmed by identification of nine P. vivax-infected specimen pools. Future malaria eradication strategies in Panama should focus on indigenous comarcas and include both active surveillance for cases and comprehensive anopheline vector surveys.

  10. Epidemic and Non-Epidemic Hot Spots of Malaria Transmission Occur in Indigenous Comarcas of Panama

    Science.gov (United States)

    Dutari, Larissa C.; Rovira, Jose R.; Sucupira, Izis M. C.; Póvoa, Marinete M.; Conn, Jan E.; Loaiza, Jose R.

    2016-01-01

    From 2002–2005, Panama experienced a malaria epidemic that has been associated with El Niño Southern Oscillation weather patterns, decreased funding for malaria control, and landscape modification. Case numbers quickly decreased afterward, and Panama is now in the pre-elimination stage of malaria eradication. To achieve this new goal, the characterization of epidemiological risk factors, foci of transmission, and important anopheline vectors is needed. Of the 24,681 reported cases in these analyses (2000–2014), ~62% occurred in epidemic years and ~44% in indigenous comarcas (5.9% of Panama’s population). Sub-analyses comparing overall numbers of cases in epidemic and non-epidemic years identified females, comarcas and some 5-year age categories as those disproportionately affected by malaria during epidemic years. Annual parasites indices (APIs; number of cases per 1,000 persons) for Plasmodium vivax were higher in comarcas compared to provinces for all study years, though P. falciparum APIs were only higher in comarcas during epidemic years. Interestingly, two comarcas report increasing numbers of cases annually, despite national annual decreases. Inclusion of these comarcas within identified foci of malaria transmission confirmed their roles in continued transmission. Comparison of species distribution models for two important anophelines with Plasmodium case distribution suggest An. albimanus is the primary malaria vector in Panama, confirmed by identification of nine P. vivax-infected specimen pools. Future malaria eradication strategies in Panama should focus on indigenous comarcas and include both active surveillance for cases and comprehensive anopheline vector surveys. PMID:27182773

  11. Developing Universal Influenza Vaccines: Hitting the Nail, Not Just on the Head

    NARCIS (Netherlands)

    L.C.M. Wiersma (Lidewij); G.F. Rimmelzwaan (Guus); R.D. de Vries (Rory)

    2016-01-01

    textabstractInfluenza viruses have a huge impact on public health. Current influenza vaccines need to be updated annually and protect poorly against antigenic drift variants or novel emerging subtypes. Vaccination against influenza can be improved in two important ways, either by inducing more broad

  12. Mathematical models to characterize early epidemic growth: A review

    Science.gov (United States)

    Chowell, Gerardo; Sattenspiel, Lisa; Bansal, Shweta; Viboud, Cécile

    2016-09-01

    There is a long tradition of using mathematical models to generate insights into the transmission dynamics of infectious diseases and assess the potential impact of different intervention strategies. The increasing use of mathematical models for epidemic forecasting has highlighted the importance of designing reliable models that capture the baseline transmission characteristics of specific pathogens and social contexts. More refined models are needed however, in particular to account for variation in the early growth dynamics of real epidemics and to gain a better understanding of the mechanisms at play. Here, we review recent progress on modeling and characterizing early epidemic growth patterns from infectious disease outbreak data, and survey the types of mathematical formulations that are most useful for capturing a diversity of early epidemic growth profiles, ranging from sub-exponential to exponential growth dynamics. Specifically, we review mathematical models that incorporate spatial details or realistic population mixing structures, including meta-population models, individual-based network models, and simple SIR-type models that incorporate the effects of reactive behavior changes or inhomogeneous mixing. In this process, we also analyze simulation data stemming from detailed large-scale agent-based models previously designed and calibrated to study how realistic social networks and disease transmission characteristics shape early epidemic growth patterns, general transmission dynamics, and control of international disease emergencies such as the 2009 A/H1N1 influenza pandemic and the 2014-2015 Ebola epidemic in West Africa.

  13. Dynamics of beneficial epidemics

    CERN Document Server

    Berdahl, Andrew; De Bacco, Caterina; Dumas, Marion; Ferdinand, Vanessa; Grochow, Joshua A; Hébert-Dufresne, Laurent; Kallus, Yoav; Kempes, Christopher P; Kolchinsky, Artemy; Larremore, Daniel B; Libby, Eric; Power, Eleanor A; Stern, Caitlin A; Tracey, Brendan

    2016-01-01

    Pathogens can spread epidemically through populations. Beneficial contagions, such as viruses that enhance host survival or technological innovations that improve quality of life, also have the potential to spread epidemically. How do the dynamics of beneficial biological and social epidemics differ from those of detrimental epidemics? We investigate this question using three theoretical approaches as well as an empirical analysis of concept propagation. First, in evolutionary models, we show that a beneficial horizontally-transmissible element, such as viral DNA, spreads super-exponentially through a population, substantially more quickly than a beneficial mutation. Second, in an epidemiological social network approach, we show that infections that cause increased connectivity lead to faster-than-exponential fixation in the population. Third, in a sociological model with strategic rewiring, we find that preferences for increased global infection accelerate spread and produce super-exponential fixation rates,...

  14. The global transmission and control of influenza.

    Directory of Open Access Journals (Sweden)

    Eben Kenah

    Full Text Available New strains of influenza spread around the globe via the movement of infected individuals. The global dynamics of influenza are complicated by different patterns of influenza seasonality in different regions of the world. We have released an open-source stochastic mathematical model of the spread of influenza across 321 major, strategically located cities of the world. Influenza is transmitted between cities via infected airline passengers. Seasonality is simulated by increasing the transmissibility in each city at the times of the year when influenza has been observed to be most prevalent. The spatiotemporal spread of pandemic influenza can be understood through clusters of global transmission and links between them, which we identify using the epidemic percolation network (EPN of the model. We use the model to explain the observed global pattern of spread for pandemic influenza A(H1N1 2009-2010 (pandemic H1N1 2009 and to examine possible global patterns of spread for future pandemics depending on the origin of pandemic spread, time of year of emergence, and basic reproductive number (. We also use the model to investigate the effectiveness of a plausible global distribution of vaccine for various pandemic scenarios. For pandemic H1N1 2009, we show that the biggest impact of vaccination was in the temperate northern hemisphere. For pandemics starting in the temperate northern hemisphere in May or April, vaccination would have little effect in the temperate southern hemisphere and a small effect in the tropics. With the increasing interconnectedness of the world's population, we must take a global view of infectious disease transmission. Our open-source, computationally simple model can help public health officials plan for the next pandemic as well as deal with interpandemic influenza.

  15. Influenza activity in Thailand and occurrence in different climates.

    Science.gov (United States)

    Prachayangprecha, Slinporn; Vichaiwattana, Preeyaporn; Korkong, Sumeth; Felber, Joshua A; Poovorawan, Yong

    2015-01-01

    This study observed influenza activity between June 2009 and July 2014 in Thailand, a country in the Northern hemisphere with a tropical climate, and compared the results to activity in the United States (US) and Australia, which represent temperate climates in the Northern and Southern hemispheres, respectively. From Thailand, a total of 17,416 specimens were collected from patients exhibiting influenza-like illnesses and subjected to real-time PCR for the detection of influenza viruses. For comparison, laboratory confirmations of influenza originating from the US and Australia were obtained from the US CDC's FluView surveillance reports and the Australian Government's Department of Health and Ageing websites. We found that, generally, the influenza season in Thailand starts with the rainy season. This observation of influenza's annual incidence pattern provides a better understanding of its occurrence, suggesting that vaccination campaigns should be started before the influenza season begins in order to reduce transmission.

  16. An exploration of the effects of pandemic influenza on infant mortality in Toronto, 1917–1921

    Directory of Open Access Journals (Sweden)

    Stacey Hallman

    2012-01-01

    Full Text Available This study investigates infant mortality from pandemic influenza in Toronto, Canada, from September to December 1918, through theRegistered Death Records of the Province of Ontario. A comparison of infant deaths in 1918 to surrounding years (1917–21 revealedthat although mortality rates remained relatively stable, there were changes in the mortality profile during the epidemic. Deaths frominfluenza did increase slightly, and the epidemic altered the expected sex ratio of infant deaths. Although communities may be greatly strained by an influenza epidemic, the infant mortality rate may be more representative of long-term social and environmental conditions rather than acute, intensive crises.

  17. Modularity promotes epidemic recurrence

    CERN Document Server

    Jesan, T; Sinha, Sitabhra

    2016-01-01

    The long-term evolution of epidemic processes depends crucially on the structure of contact networks. As empirical evidence indicates that human populations exhibit strong community organization, we investigate here how such mesoscopic configurations affect the likelihood of epidemic recurrence. Through numerical simulations on real social networks and theoretical arguments using spectral methods, we demonstrate that highly contagious diseases that would have otherwise died out rapidly can persist indefinitely for an optimal range of modularity in contact networks.

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

    Science.gov (United States)

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

    2013-02-01

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

  19. The Relationship between Tuberculosis and Influenza Death during the Influenza (H1N1 Pandemic from 1918-19

    Directory of Open Access Journals (Sweden)

    Welling Oei

    2012-01-01

    Full Text Available The epidemiological mechanisms behind the W-shaped age-specific influenza mortality during the Spanish influenza (H1N1 pandemic 1918-19 have yet to be fully clarified. The present study aimed to develop a formal hypothesis: tuberculosis (TB was associated with the W-shaped influenza mortality from 1918-19. Three pieces of epidemiological information were assessed: (i the epidemic records containing the age-specific numbers of cases and deaths of influenza from 1918-19, (ii an outbreak record of influenza in a Swiss TB sanatorium during the pandemic, and (iii the age-dependent TB mortality over time in the early 20th century. Analyzing the data (i, we found that the W-shaped pattern was not only seen in mortality but also in the age-specific case fatality ratio, suggesting the presence of underlying age-specific risk factor(s of influenza death among young adults. From the data (ii, TB was shown to be associated with influenza death (P=0.09, and there was no influenza death among non-TB controls. The data (iii were analyzed by employing the age-period-cohort model, revealing harvesting effect in the period function of TB mortality shortly after the 1918-19 pandemic. These findings suggest that it is worthwhile to further explore the role of TB in characterizing the age-specific risk of influenza death.

  20. Inhibition of MLC phosphorylation restricts replication of influenza virus--a mechanism of action for anti-influenza agents.

    Directory of Open Access Journals (Sweden)

    Mehran Haidari

    Full Text Available Influenza A viruses are a severe threat worldwide, causing large epidemics that kill thousands every year. Prevention of influenza infection is complicated by continuous viral antigenic changes. Newer anti-influenza agents include MEK/ERK and protein kinase C inhibitors; however, the downstream effectors of these pathways have not been determined. In this study, we identified a common mechanism for the inhibitory effects of a significant group of anti-influenza agents. Our studies showed that influenza infection activates a series of signaling pathways that converge to induce myosin light chain (MLC phosphorylation and remodeling of the actin cytoskeleton. Inhibiting MLC phosphorylation by blocking RhoA/Rho kinase, phospholipase C/protein kinase C, and HRas/Raf/MEK/ERK pathways with the use of genetic or chemical manipulation leads to the inhibition of influenza proliferation. In contrast, the induction of MLC phosphorylation enhances influenza proliferation, as does activation of the HRas/Raf/MEK/ERK signaling pathway. This effect is attenuated by inhibiting MLC phosphorylation. Additionally, in intracellular trafficking studies, we found that the nuclear export of influenza ribonucleoprotein depends on MLC phosphorylation. Our studies provide evidence that modulation of MLC phosphorylation is an underlying mechanism for the inhibitory effects of many anti-influenza compounds.

  1. 鸡新城疫、传染性支气管炎、禽流感(H9亚型)三联灭活疫苗对禽流感H9亚型流行株攻毒的保护作用%Protective efficiency of the inactivated Newcastle disease virus, infectious bronchitis virus and avian influenza virus (H9 subtype) vaccine against epidemic strains of avian influenza virus H9

    Institute of Scientific and Technical Information of China (English)

    林绮萍; 陈瑞爱; 黄文科; 区德庆; 严洁珍

    2012-01-01

    To monitor the protective efficiency of the inactivated Newcastle disease virus, infectious bronchitis virus and avian influenza virus H9 subtype (AIV-H9) vaccine (LaSota + M41 + SS/94), SPF chickens were respectively inoculated with strain SS/94 and three epidemic strains of AIV-H9 isolated during 2009-2010, after being immunized with the inactivated vaccine. The results showed that at 21 days after immunization, the HI antibody titers to AIV-H9 in the experimental chickens varied from 81og2 to lllog2. The antibody levels had protective ability against the challenge with 2x106EID50 of AIV-H9 strains including SS/94, BLCN09, WDZ09 and YT10, and the protection rates were above 90% (9/10). It suggested that the triple inactivated vaccine with the strain SS/94 used as the AIV antigen could induce protective immunity against challenge with epidemic strains of AIV-H9.%为了监测鸡新城疫、传染性支气管炎、禽流感(H9亚型)三联灭活疫苗(LaSota株+M41株+SS/94株)对H9亚型禽流感病毒流行毒株的免疫保护效果,采用H9亚型禽流感病毒SS/94株及2009-2010年现地分离的3株H9亚型禽流感病毒对已免疫上述三联灭活苗的SPF鸡进行攻毒试验.结果显示,试验鸡以0.3 mL/只的剂量免疫三联灭活苗后21 d,其H9亚型禽流感病毒的HI抗体效价可达8~ 11log2,此抗体水平可抵抗2×106 EID50的H9亚型禽流感病毒SS/94株、BLCN09株、WDZ09株、YT10株的攻击,攻毒保护率均达90% (9/10)以上.可见,以SS/94株作为禽流感疫苗抗原制备的三联灭活苗具有良好的免疫原性,能使免疫鸡抵抗2009-2010年期间现地分离的多株H9亚型禽流感病毒的攻击.

  2. Population estimates of persons presenting to general practitioners with influenza-like illness, 1987-96: a study of the demography of influenza-like illness in sentinel practice networks in England and Wales, and in The Netherlands.

    NARCIS (Netherlands)

    Fleming, D.M.; Zambon, M.; Bartelds, A.I.M.

    2000-01-01

    Incidence data by age of new episodes of influenza-like illness reported by sentinel general practice networks in England and Wales and in The Netherlands over a 10-year period were examined to provide estimates of the consulting population during influenza epidemic periods. Baseline levels of recor

  3. Free-grazing ducks and highly pathogenic avian influenza, Thailand

    NARCIS (Netherlands)

    Gilbert, Marius; Chaitaweesup, P.; Parakamawongsa, T.; Premashthira, S.; Tiensin, T.; Kalpravidh, W.; Wagner, H.; Slingenbergh, J.

    2006-01-01

    Thailand has recently had 3 epidemic waves of highly pathogenic avian influenza (HPAI); virus was again detected in July 2005. Risk factors need to be identified to better understand disease ecology and assist HPAI surveillance and detection. This study analyzed the spatial distribution of HPAI outb

  4. Avian Influenza A (H7N9) Virus

    Science.gov (United States)

    ... this? Submit Button Past Newsletters Avian Influenza A (H7N9) Virus Language: English Español Recommend on Facebook ... Fourth Epidemic — China, September 2015–August 2016." H7N9 Outbreak Characterization H7N9 infections in people and poultry ...

  5. Morbidity, Mortality, and Seasonality of Influenza Hospitalizations in Egypt, November 2007-November 2014

    Science.gov (United States)

    Kandeel, Amr; Labib, Manal; Said, Mayar; El-Refai, Samir; El-Gohari, Amani; Talaat, Maha

    2016-01-01

    Background Influenza typically comprises a substantial portion of acute respiratory infections, a leading cause of mortality worldwide. However, influenza epidemiology data are lacking in Egypt. We describe seven years of Egypt’s influenza hospitalizations from a multi-site influenza surveillance system. Methods Syndromic case definitions identified individuals with severe acute respiratory infection (SARI) admitted to eight hospitals in Egypt. Standardized demographic and clinical data were collected. Nasopharyngeal and oropharyngeal swabs were tested for influenza using real-time reverse transcription polymerase chain reaction and typed as influenza A or B, and influenza A specimens subtyped. Results From November 2007–November 2014, 2,936/17,441 (17%) SARI cases were influenza-positive. Influenza-positive patients were more likely to be older, female, pregnant, and have chronic condition(s) (all p<0.05). Among them, 53 (2%) died, and death was associated with older age, five or more days from symptom onset to hospitalization, chronic condition(s), and influenza A (all p<0.05). An annual seasonal influenza pattern occurred from July–June. Each season, the proportion of the season’s influenza-positive cases peaked during November–May (19–41%). Conclusions In Egypt, influenza causes considerable morbidity and mortality and influenza SARI hospitalization patterns mirror those of the Northern Hemisphere. Additional assessment of influenza epidemiology in Egypt may better guide disease control activities and vaccine policy. PMID:27607330

  6. Influenza en RS-virusinfecties in winter 2000/2001: stand van zaken op 12 februari 2001.

    NARCIS (Netherlands)

    Heijnen, M.L.A.; Bartelds, A.I.M.; Jong, J.C. de; Rimmelzwaan, G.F.; Wilbrink, B.

    2001-01-01

    Until now it has been quiet concerning influenza this winter in the Netherlands, but possibly we are at the verge of the yearly epidemic. All but one Dutch influenza virus isolates characterised so far are of the A(H1N1) subtype and are related closely to the strain for this subtype in the vaccine.

  7. Configuring the autism epidemic

    DEFF Research Database (Denmark)

    Christensen, Fie Lund Lindegaard; Seeberg, Jens

    2017-01-01

    Autism has been described as an epidemic, but this claim is contested and may point to an awareness epidemic, i.e. changes in the definition of what autism is and more attention being invested in diagnosis leading to a rise in registered cases. The sex ratio of children diagnosed with autism...... is skewed in favour of boys, and girls with autism tend to be diagnosed much later than boys. Building and further developing the notion of ‘configuration’ of epidemics, this article explores the configuration of autism in Denmark, with a particular focus on the health system and social support to families...... with children diagnosed with autism, seen from a parental perspective. The article points to diagnostic dynamics that contribute to explaining why girls with autism are not diagnosed as easily as boys. We unfold these dynamics through the analysis of a case of a Danish family with autism....

  8. The Epidemics of Corruption

    CERN Document Server

    Blanchard, P; Krüger, T; Martin, P; Blanchard, Ph.

    2005-01-01

    We study corruption as a generalized epidemic process on the graph of social relationships. The main difference to classical epidemic processes is the strong nonlinear dependence of the transmission probability on the local density of corruption and the mean field influence of the overall corruption in the society. Network clustering and the degree-degree correlation play an essential role in corruption dynamics. We discuss phase transitions, the influence of the graph structure and the implications for epidemic control. Structural and dynamical arguments are given why strongly hierarchically organized societies like systems with dictatorial tendency are more vulnerable to corruption than democracies. A similar type of modelling can be applied to other social contagion spreading processes like opinion formation, doping usage, social disorders or innovation dynamics.

  9. Seasonal Influenza Questions & Answers

    Science.gov (United States)

    ... and Flu Vaccines Vaccine Effectiveness Types of Flu Vaccine Flu Shot Quadrivalent Influenza Vaccine Intradermal Influenza (Flu) Vaccination ... Cell-Based Flu Vaccines Flublok Seasonal Influenza (Flu) Vaccine Flu Vaccination by Jet Injector Adjuvant Vaccine Vaccine Virus ...

  10. Avian Influenza in Birds

    Science.gov (United States)

    ... this? Submit Button Past Newsletters Avian Influenza in Birds Language: English Español Recommend on Facebook Tweet ... illness. Top of Page Avian Influenza in Wild Birds Avian influenza A viruses have been isolated from ...

  11. Use of computational and recombinant technologies for developing novel influenza vaccines.

    Science.gov (United States)

    Wong, Terianne M; Ross, Ted M

    2016-01-01

    Influenza vaccine design has changed considerably with advancements in bioinformatics and computational biology. Improved surveillance efforts provide up-to-date information about influenza sequence diversity and assist with monitoring the spread of epidemics and vaccine efficacy rates. The advent of next-generation sequencing, epitope scanning and high-throughput analysis all help decipher influenza-associated protein interactions as well as predict immune responsiveness based on host genetic diversity. Computational approaches are utilized in nearly all aspects of vaccine design, from modeling, compatibility predictions, and optimization of antigens in various platforms. This overview discusses how computational techniques strengthen vaccine efforts against highly diverse influenza species.

  12. Numerous cerebral hemorrhages in a patient with influenza-associated encephalitis: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ji Ye; Seong, Su Ok; Park, Noh Hyuck; Park, Chan Sup [Dept. of Radiology, Myongji Hospital, Goyang (Korea, Republic of)

    2016-02-15

    Influenza-associated encephalitis (IAE) is a complication of a common disease that is rare even during an epidemic. Awareness of magnetic resonance imaging features of IAE is important in treatment planning and prognosis estimation. Several reports have described necrotizing encephalopathy in children with influenza. However, few reports have described multifocal hemorrhages in both cerebral hemispheres in adults with concomitant infection with influenza A and B. Here, we describe a case of influenza A- and B-associated encephalitis accompanied by numerous cerebral hemorrhages.

  13. Interim Estimates of 2016-17 Seasonal Influenza Vaccine Effectiveness - United States, February 2017.

    Science.gov (United States)

    Flannery, Brendan; Chung, Jessie R; Thaker, Swathi N; Monto, Arnold S; Martin, Emily T; Belongia, Edward A; McLean, Huong Q; Gaglani, Manjusha; Murthy, Kempapura; Zimmerman, Richard K; Nowalk, Mary Patricia; Jackson, Michael L; Jackson, Lisa A; Foust, Angie; Sessions, Wendy; Berman, LaShondra; Spencer, Sarah; Fry, Alicia M

    2017-02-17

    In the United States, annual vaccination against seasonal influenza is recommended for all persons aged ≥6 months (1). Each influenza season since 2004-05, CDC has estimated the effectiveness of seasonal influenza vaccine to prevent influenza-associated, medically attended, acute respiratory illness (ARI). This report uses data, as of February 4, 2017, from 3,144 children and adults enrolled in the U.S. Influenza Vaccine Effectiveness Network (U.S. Flu VE Network) during November 28, 2016-February 4, 2017, to estimate an interim adjusted effectiveness of seasonal influenza vaccine for preventing laboratory-confirmed influenza virus infection associated with medically attended ARI. During this period, overall vaccine effectiveness (VE) (adjusted for study site, age group, sex, race/ethnicity, self-rated general health, and days from illness onset to enrollment) against influenza A and influenza B virus infection associated with medically attended ARI was 48% (95% confidence interval [CI] = 37%-57%). Most influenza infections were caused by A (H3N2) viruses. VE was estimated to be 43% (CI = 29%-54%) against illness caused by influenza A (H3N2) virus and 73% (CI = 54%-84%) against influenza B virus. These interim VE estimates indicate that influenza vaccination reduced the risk for outpatient medical visits by almost half. Because influenza activity remains elevated (2), CDC and the Advisory Committee on Immunization Practices recommend that annual influenza vaccination efforts continue as long as influenza viruses are circulating (1). Vaccination with 2016-17 influenza vaccines will reduce the number of infections with most currently circulating influenza viruses. Persons aged ≥6 months who have not yet been vaccinated this season should be vaccinated as soon as possible.

  14. Recurrence of Panic Attacks after Influenza Vaccination: Two Case Reports

    Science.gov (United States)

    Kim, Han-Joon; Jeon, Sang-Won; Yoon, Ho-Kyoung

    2016-01-01

    Human influenza is a contagious respiratory illness caused by the influenza virus. The influenza vaccination is recommended annually, but several adverse effects related to allergic reactions have been reported. Panic attacks are also known to occur, but no case of a panic attack adverse effect has been reported in South Korea. We present two cases of panic disorder patients whose symptoms were aggravated by the influenza vaccination. We assumed that dysregulation of T-lymphocytes in panic disorder patients could have a role in activating various kinds of cytokines and chemokines, which then can lead to panic attack aggravation. PMID:27776395

  15. 42 CFR 405.2466 - Annual reconciliation.

    Science.gov (United States)

    2010-10-01

    ... § 405.2466 Annual reconciliation. (a) General. Payments made to a rural health clinic or a Federally..., payment for pneumococcal and influenza vaccine and their administration is 100 percent of...

  16. Epidemic Intelligence. Langmuir and the Birth of Disease Surveillance

    Directory of Open Access Journals (Sweden)

    Lyle Fearnley

    2010-12-01

    Full Text Available In the wake of the SARS and influenza epidemics of the past decade, one public health solution has become a refrain: surveillance systems for detection of disease outbreaks. This paper is an effort to understand how disease surveillance for outbreak detection gained such paramount rationality in contemporary public health. The epidemiologist Alexander Langmuir is well known as the creator of modern disease surveillance. But less well known is how he imagined disease surveillance as one part of what he called “epidemic intelligence.” Langmuir developed the practice of disease surveillance during an unprecedented moment in which the threat of biological warfare brought civil defense experts and epidemiologists together around a common problem. In this paper, I describe how Langmuir navigated this world, experimenting with new techniques and rationales of epidemic control. Ultimately, I argue, Langmuir′s experiments resulted in a set of techniques and infrastructures – a system of epidemic intelligence – that transformed the epidemic as an object of human art.

  17. Epidemic Threats to the European Union: Expert Views on Six Virus Groups

    NARCIS (Netherlands)

    Kelly, L.; Brouwer, A.; Wilson, A.; Gale, P.; Snary, E.; Ross, D.; Vos, de C.J.

    2013-01-01

    In recent years, several animal disease epidemics have occurred within the European Union (EU). At the 4th Annual Meeting of the EPIZONE network (7-10 June 2010, St. Malo, France), an interactive session was run to elicit the opinions of delegates on a pre-defined list of epidemic threats to the EU.

  18. Study of the radiation effects on nucleic acids and related compounds. Annual progress report, August 15, 1974--August 14, 1975. [X radiation, hamster cells, Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.Y.

    1975-01-01

    Interest is being centered on the chemical and physical nature of radiation-induced lesions to nucleic acids and their components. These investigations have revealed the enormous complexity of chemical events in these systems and the possible degradation of nucleic acids by strand breakage. Therefore, work in the ionizing radiation of DNA and its components has proceeded along a dual course. For chemical studies, our prime concern is the stepwise isolation and identification of the radiation products of derivatives of pyrimidines and the study of the actual mechanisms of their formation. For biological studies, H. influenzae cells, the Chinese hamster V79B-1 cell line, and the Dunn osteosarcoma lung colony system were used. During the last year, the method of synthesis of 5-hydroperoxymethyluracil (T/sub ..cap alpha../OOH) was greatly improved. Large-scale preparation of 5-hydroxy-6-hydroperoxy-5,6-dihydrothymine (T/sup 6/OOH) were carried out in order to study the action of T/sup 6/OOH on neighboring bases, glycosidic bond-breakage, cell mutagenesis, chromosomal aberrations, and possible synergistic effects on x radiation. These results allow one to relate radiobiological effects with radiation chemical changes in DNA.

  19. Optimal pandemic influenza vaccine allocation strategies for the Canadian population.

    Directory of Open Access Journals (Sweden)

    Ashleigh R Tuite

    Full Text Available BACKGROUND: The world is currently confronting the first influenza pandemic of the 21(st century. Influenza vaccination is an effective preventive measure, but the unique epidemiological features of swine-origin influenza A (H1N1 (pH1N1 introduce uncertainty as to the best strategy for prioritization of vaccine allocation. We sought to determine optimal prioritization of vaccine distribution among different age and risk groups within the Canadian population, to minimize influenza-attributable morbidity and mortality. METHODOLOGY/PRINCIPAL FINDINGS: We developed a deterministic, age-structured compartmental model of influenza transmission, with key parameter values estimated from data collected during the initial phase of the epidemic in Ontario, Canada. We examined the effect of different vaccination strategies on attack rates, hospitalizations, intensive care unit admissions, and mortality. In all scenarios, prioritization of high-risk individuals (those with underlying chronic conditions and pregnant women, regardless of age, markedly decreased the frequency of severe outcomes. When individuals with underlying medical conditions were not prioritized and an age group-based approach was used, preferential vaccination of age groups at increased risk of severe outcomes following infection generally resulted in decreased mortality compared to targeting vaccine to age groups with higher transmission, at a cost of higher population-level attack rates. All simulations were sensitive to the timing of the epidemic peak in relation to vaccine availability, with vaccination having the greatest impact when it was implemented well in advance of the epidemic peak. CONCLUSIONS/SIGNIFICANCE: Our model simulations suggest that vaccine should be allocated to high-risk groups, regardless of age, followed by age groups at increased risk of severe outcomes. Vaccination may significantly reduce influenza-attributable morbidity and mortality, but the benefits are

  20. Dynamics of public opinion under the influence of epidemic spreading

    Science.gov (United States)

    Wu, Junhui; Ni, Shunjiang; Shen, Shifei

    2016-02-01

    In this paper, we propose a novel model with dynamically adjusted confidence level of others to investigate the propagation of public opinion on whether to buy chicken in the case of avian influenza infection in humans. We study how people adjust their confidence level in other people’s opinions according to their perceived infection risk and how the opinion evolution and epidemic spreading affect each other on different complex networks by taking into account the spreading feature of avian influenza, that is, only people who buy chicken are possible to be infected. The simulation results show that in a closed system, people who support buying chicken and people who are infected can achieve a dynamic balance after a few time-steps, and the final stable state is mainly dependent on the level of people’s risk perception, rather than the initial distribution of the different opinions. Our results imply that in the course of the epidemic spread, transparent and timely announcement of the number of infections and the risk of infection can help people take the right self-protection actions, and thus help control the spread of avian influenza.

  1. The Obesity Epidemic

    Centers for Disease Control (CDC) Podcasts

    2011-07-18

    Learn about obesity and the community initiatives taking place to prevent and reduce this epidemic.  Created: 7/18/2011 by National Center for Chronic Disease Prevention and Health Promotion, Division of Nutrition, Physical Activity and Obesity.   Date Released: 7/18/2011.

  2. [Epidemics and diseases during the Independence period in Mexico].

    Science.gov (United States)

    Viesca-Treviño, Carlos

    2010-01-01

    The epidemics and endemic diseases in Mexico were not a problem before the Independence period. Hunger was less than in the past. The 1806 Influenza epidemics had been forgotten. Measles was considered a benign illness. In 1810, there was an increase in the number of cases of black vomit in Veracruz. Sixty percent of 541 hospitalized patients die of the disease. In 1812, an outbreak of yellow fever spread from Veracruz to Jalapa accompanying the movement of troops and killing over 300 soldiers of the Castilla's Battalion. The appearance of petechial fever, maybe typhus marketed in 1813 the onset of the most important epidemics. The preceding was the indirect effect of war: diseases of prisons and military quarters which became overwhelming in times where the movements of troops and of important groups of populations along with crowing, loss homes, hunger and bad hygiene habits. There was also Influenza or "pestilent cold." Measures of detection and quarantine were taken. "Naranjate" mixed with tartaric cremor was used against fever. Fumigation with nitric acid and burners, where they incinerated gun powder were among the health protection policies. It is noteworthy the advance and relief provided by the introduction of smallpox vaccine, the only preventive mean useful against smallpox which was a breakthrough in public health.

  3. Molecular basis of live-attenuated influenza virus.

    Directory of Open Access Journals (Sweden)

    Wen He

    Full Text Available Human influenza is a seasonal disease associated with significant morbidity and mortality. The most effective means for controlling infection and thereby reducing morbidity and mortality is vaccination with a three inactivated influenza virus strains mixture, or by intranasal administration of a group of three different live attenuated influenza vaccine strains. Comparing to the inactivated vaccine, the attenuated live viruses allow better elicitation of a long-lasting and broader immune (humoral and cellular response that represents a naturally occurring transient infection. The cold-adapted (ca influenza A/AA/6/60 (H2N2 (AA ca virus is the backbone for the live attenuated trivalent seasonal influenza vaccine licensed in the United States. Similarly, the influenza A components of live-attenuated vaccines used in Russia have been prepared as reassortants of the cold-adapted (ca H2N2 viruses, A/Leningrad/134/17/57-ca (Len/17 and A/Leningrad/134/47/57-ca (Len/47 along with virulent epidemic strains. However, the mechanism of temperature-sensitive attenuation is largely elusive. To understand how modification at genetic level of influenza virus would result in attenuation of human influenza virus A/PR/8/34 (H1N1,A/PR8, we investigated the involvement of key mutations in the PB1 and/or PB2 genes in attenuation of influenza virus in vitro and in vivo. We have demonstrated that a few of residues in PB1 and PB2 are critical for the phenotypes of live attenuated, temperature sensitive influenza viruses by minigenome assay and real-time PCR. The information of these mutation loci could be used for elucidation of mechanism of temperature-sensitive attenuation and as a new strategy for influenza vaccine development.

  4. Understanding Virtual Epidemics: Children's Folk Conceptions of a Computer Virus

    Science.gov (United States)

    Kafai, Yasmin B.

    2008-01-01

    Our work investigates the annual outbreak of Whypox, a virtual epidemic in Whyville.net, a virtual world with over 1.2 million registered players ages 8-16. We examined online and classroom participants' understanding of a computer virus using surveys and design activities. Our analyses reveal that students have a mostly naive understanding of a…

  5. Effectiveness of 2012–2013 influenza vaccine against influenza-like illness in general population

    Science.gov (United States)

    Debin, Marion; Colizza, Vittoria; Blanchon, Thierry; Hanslik, Thomas; Turbelin, Clement; Falchi, Alessandra

    2014-01-01

    Most of the methods used for estimating the influenza vaccine effectiveness (IVE) target the individuals who have an influenza-like illness (ILI) rather than virologically-proven influenza and access the healthcare system. The objective of this study was to estimate the 2012–2013 IVE in general French population, using a cohort of volunteers registered on GrippeNet.fr, an online surveillance system for ILI. The IVE estimations were obtained through a logistic regression, and analyses were also performed by focusing on at-risk population of severe influenza, and by varying inclusion period and ILI definition. Overall, 1996 individuals were included in the analyses. The corrected IVE was estimated to 49% (20 to 67) for the overall population, and 32% (0 to 58) for the at-risk population. Three covariables appeared with a significant effect on the occurrence of at least one ILI during the epidemic: the age (P = 0.045), the presence of a child in the household (P < 10−3), and the frequency of cold/flu (P < 10−3). Comparable results were found at epidemic peak time in the hypothesis of real-time feed of data. In this study, we proposed a novel, follow-up, web-based method to reveal seasonal vaccine effectiveness, which enables analysis in a portion of the population that is not tracked by the health care system in most VE studies. PMID:24343049

  6. Pandemisk influenza

    DEFF Research Database (Denmark)

    Andersen, Nina Blom; Almlund, Pernille

    danske myndigheder kommunikerede åbent og løbende om influenza-krisen og dens trusler. Indsatsen blev anerkendt fra alle sider og førte på intet tidspunkt til alvorlig og længerevarende kritik af myndighederne. Der var tale om en tilfredsstillende krisehåndtering, hvad angår den del, der fokuserede på...... kommunikation om denne tog en drejning i forhold til selve influenza-krisen. Myndighedernes kommunikation blev mere uklar, forvirringen voksede i befolkningen, og der blev rejst kritik i offentligheden. Forløbet rejser spørgsmålene om, den samlede håndtering af kommunikationsindsatsen kunne have været mere...

  7. The new school absentees reporting system for pandemic influenza A/H1N1 2009 infection in Japan.

    Directory of Open Access Journals (Sweden)

    Takeshi Suzue

    Full Text Available OBJECTIVE: To evaluate the new Japanese School Absentees Reporting System for Infectious Disease (SARSID for pandemic influenza A/H1N1 2009 infection in comparison with the National epidemiological Surveillance of Infectious Disease (NESID. METHODS: We used data of 53,223 students (97.7% in Takamatsu city Japan. Data regarding school absentees in SARSID was compared with that in NESID from Oct 13, 2009 to Jan 12, 2010. RESULTS: Similar trends were observed both in SARSID and NESID. However, the epidemic trend for influenza in SARSID was thought to be more sensitive than that in NESID. CONCLUSION: The epidemic trend for influenza among school-aged children could be easily and rapidly assessed by SARSID compared to NESID. SARSID might be useful for detecting the epidemic trend of influenza.

  8. Targeting influenza in Kentucky.

    Science.gov (United States)

    Bennett, John M; Casey, Baretta; Samuels, Michael E; Whitler, Elmer

    2007-12-01

    Kentucky has the 5th highest influenza-related death rate in the United States with about 1000 Kentuckians dying each year from complications of influenza. The majority of these patients are in identifiable risk groups for complications of influenza. Yearly immunizations with the influenza vaccine reduce the risk for hospitalization and death.

  9. Avian influenza

    Directory of Open Access Journals (Sweden)

    Tjandra Y. Aditama

    2006-06-01

    Full Text Available Avian influenza, or “bird flu”, is a contagious disease of animals which crossed the species barrier to infect humans and gave a quite impact on public health in the world since 2004, especially due to the threat of pandemic situation. Until 1st March 2006, laboratory-confirmed human cases have been reported in seven countries: Cambodia, Indonesia, Thailand, Viet Nam, China, Iraq and Turkey with a total of 174 cases and 94 dead (54.02%. Indonesia has 27 cases, 20 were dead (74.07%. AI cases in Indonesia are more in male (62.5% and all have a symptom of fever. An influenza pandemic is a rare but recurrent event. An influenza pandemic happens when a new subtype emerges that has not previously circulated in humans. For this reason, avian H5N1 is a strain with pandemic potential, since it might ultimately adapt into a strain that is contagious among humans. Impact of the pandemic could include high rates of illness and worker absenteeism are expected, and these will contribute to social and economic disruption. Historically, the number of deaths during a pandemic has varied greatly. Death rates are largely determined by four factors: the number of people who become infected, the virulence of the virus, the underlying characteristics and vulnerability of affected populations, and the effectiveness of preventive measures. Accurate predictions of mortality cannot be made before the pandemic virus emerges and begins to spread. (Med J Indones 2006; 15:125-8Keywords: Avian Influenza, Pandemic

  10. Resilience of epidemics on networks

    CERN Document Server

    Lu, Dan; Zhang, Jiaquan; Wang, Huijuan; Li, Daqing

    2016-01-01

    Epidemic propagation on complex networks has been widely investigated, mostly with invariant parameters. However, the process of epidemic propagation is not always constant. Epidemics can be affected by various perturbations, and may bounce back to its original state, which is considered resilient. Here, we study the resilience of epidemics on networks, by introducing a different infection rate ${\\lambda_{2}}$ during SIS (susceptible-infected-susceptible) epidemic propagation to model perturbations (control state), whereas the infection rate is ${\\lambda_{1}}$ in the rest of time. Through simulations and theoretical analysis, we find that even for ${\\lambda_{2}<\\lambda_{c}}$, epidemics eventually could bounce back if control duration is below a threshold. This critical control time for epidemic resilience, i.e., ${cd_{max}}$ can be predicted by the diameter (${d}$) of the underlying network, with the quantitative relation ${cd_{max}\\sim d^{\\alpha}}$. Our findings can help to design a better mitigation stra...

  11. Power law incidence rate in epidemic models. Comment on: "Mathematical models to characterize early epidemic growth: A review" by Gerardo Chowell et al.

    Science.gov (United States)

    Allen, Linda J. S.

    2016-09-01

    Dr. Chowell and colleagues emphasize the importance of considering a variety of modeling approaches to characterize the growth of an epidemic during the early stages [1]. A fit of data from the 2009 H1N1 influenza pandemic and the 2014-2015 Ebola outbreak to models indicates sub-exponential growth, in contrast to the classic, homogeneous-mixing SIR model with exponential growth. With incidence rate βSI / N and S approximately equal to the total population size N, the number of new infections in an SIR epidemic model grows exponentially as in the differential equation,

  12. Proximity Networks and Epidemics

    CERN Document Server

    Toroczkai, Z

    2007-01-01

    Disease spread in most biological populations requires the proximity of agents. In populations where the individuals have spatial mobility, the contact graph is generated by the "collision dynamics" of the agents, and thus the evolution of epidemics couples directly to the spatial dynamics of the population. We first briefly review the properties and the methodology of an agent-based simulation (EPISIMS) to model disease spread in realistic urban dynamic contact networks. Using the data generated by this simulation, we introduce the notion of dynamic proximity networks which takes into account the relevant time scales for disease spread: contact duration, infectivity period and rate of contact creation. This approach promises to be a good candidate for a unified treatment of epidemic types that are driven by agent collision dynamics. In particular, using a simple model, we show that it can can account for the observed qualitative differences between the degree distributions of contact graphs of diseases with ...

  13. Segurança, imunogenicidade e eficácia da vacina contra o vírus influenza em crianças Safety, immunogenicity and efficacy of influenza vaccine in children

    Directory of Open Access Journals (Sweden)

    Otávio A. L. Cintra

    2006-07-01

    search of the medical literature indexed on MEDLINE, LILACS and in the Cochrane Library. Review articles, clinical trials and epidemiological studies published from 1990 to 2006 were selected for analysis. SUMMARY OF THE FINDINGS: Influenza is an infectious disease that is both universal and seasonal, with incidence in all age groups and annual epidemics characterized by excessive morbidity and mortality. The elderly and people with comorbidity are high risk groups for severe influenza. It has recently been proven that healthy infants suffer similar morbidity to other risk groups, and therefore vaccination against influenza is indicated for them too, as being the most effective means of preventing infection by the influenza virus. The safety of influenza vaccines in children appears adequate, with the most often observed adverse effects being local reactions or fever. Immunogenicity in children varies from 30 to 90%, being directly proportional to age. Efficacy depends on the primary objective and can range from levels comparable with placebo to up to 91% efficacy against confirmed influenza A infection. Schoolchildren play an important role in the dissemination of the influenza virus, and population studies have demonstrated herd immunity. CONCLUSIONS: Trivalent influenza vaccines, whether inactivated or attenuated, have low reactogenicity and offer variable immunogenicity and efficacy in children. Vaccination is effective for prevention of infections by the influenza virus and for reducing morbidity. More powerful studies of efficacy and safety in infants are still required.

  14. Influenza vaccination in children at high risk of respiratory disease.

    Science.gov (United States)

    Patria, Maria Francesca; Tagliabue, Claudia; Longhi, Benedetta; Esposito, Susanna

    2013-05-01

    Chronic respiratory diseases (CRDs) are a heterogeneous group of diseases that can affect the pediatric population and health authorities throughout the world recommend influenza vaccination because of the significant risk of influenza-related complications. However, despite this recommendation, vaccine coverage is generally unsatisfactory. The aim of this review is to analyze the impact of influenza on children at high risk of respiratory disease, and the immunogenicity, safety and efficacy of influenza vaccination in such children. The results show that there is a significant risk of influenza-related complications in preterm neonates and infants, in whom influenza vaccines are immunogenic and safe (although their efficacy has not been specifically studied). There are conflicting data concerning the effect of influenza infection on asthma morbidity in children, and whether or not influenza vaccination helps to prevent asthma exacerbations. Recent data provide no evidence that influenza is more frequent in patients with cystic fibrosis than in healthy subjects, or that it is responsible for increased lower respiratory tract morbidity. The lack of any clear correlate of protection suggests that future studies should also consider the efficacy of the different influenza vaccines and not only evaluate them in terms of immunogenicity. Furthermore, there is a need for clinical studies to assess the effectiveness of the available vaccines in patients with other rare CRDs and other chronic underlying diseases with possibly severe respiratory involvement. It is also important to determine whether children with recurrent respiratory tract infections should be included in the list of those for whom influenza vaccination is recommended. In the meantime, given the increasing evidence of the burden of influenza on the population as a whole and the benefits associated with vaccination, annual influenza vaccinations should be recommended for all children at high risk of

  15. The influence of meteorology on the spread of influenza: survival analysis of an equine influenza (A/H3N8) outbreak.

    Science.gov (United States)

    Firestone, Simon M; Cogger, Naomi; Ward, Michael P; Toribio, Jenny-Ann L M L; Moloney, Barbara J; Dhand, Navneet K

    2012-01-01

    The influences of relative humidity and ambient temperature on the transmission of influenza A viruses have recently been established under controlled laboratory conditions. The interplay of meteorological factors during an actual influenza epidemic is less clear, and research into the contribution of wind to epidemic spread is scarce. By applying geostatistics and survival analysis to data from a large outbreak of equine influenza (A/H3N8), we quantified the association between hazard of infection and air temperature, relative humidity, rainfall, and wind velocity, whilst controlling for premises-level covariates. The pattern of disease spread in space and time was described using extraction mapping and instantaneous hazard curves. Meteorological conditions at each premises location were estimated by kriging daily meteorological data and analysed as time-lagged time-varying predictors using generalised Cox regression. Meteorological covariates time-lagged by three days were strongly associated with hazard of influenza infection, corresponding closely with the incubation period of equine influenza. Hazard of equine influenza infection was higher when relative humidity was 30 km hour(-1) from the direction of nearby infected premises were associated with increased hazard of infection. Through combining detailed influenza outbreak and meteorological data, we provide empirical evidence for the underlying environmental mechanisms that influenced the local spread of an outbreak of influenza A. Our analysis supports, and extends, the findings of studies into influenza A transmission conducted under laboratory conditions. The relationships described are of direct importance for managing disease risk during influenza outbreaks in horses, and more generally, advance our understanding of the transmission of influenza A viruses under field conditions.

  16. Impact of preventive responses to epidemics in rural regions.

    Science.gov (United States)

    Schumm, Phillip; Schumm, Walter; Scoglio, Caterina

    2013-01-01

    Various epidemics have arisen in rural locations through human-animal interaction, such as the H1N1 outbreak of 2009. Through collaboration with local government officials, we have surveyed a rural county and its communities and collected a dataset characterizing the rural population. From the respondents' answers, we build a social (face-to-face) contact network. With this network, we explore the potential spread of epidemics through a Susceptible-Latent-Infected-Recovered (SLIR) disease model. We simulate an exact model of a stochastic SLIR Poisson process with disease parameters representing a typical influenza-like illness. We test vaccine distribution strategies under limited resources. We examine global and location-based distribution strategies, as a way to reach critical individuals in the rural setting. We demonstrate that locations can be identified through contact metrics for use in vaccination strategies to control contagious diseases.

  17. Gnarled-trunk evolutionary model of influenza A virus hemagglutinin.

    Directory of Open Access Journals (Sweden)

    Kimihito Ito

    Full Text Available Human influenza A viruses undergo antigenic changes with gradual accumulation of amino acid substitutions on the hemagglutinin (HA molecule. A strong antigenic mismatch between vaccine and epidemic strains often requires the replacement of influenza vaccines worldwide. To establish a practical model enabling us to predict the future direction of the influenza virus evolution, relative distances of amino acid sequences among past epidemic strains were analyzed by multidimensional scaling (MDS. We found that human influenza viruses have evolved along a gnarled evolutionary pathway with an approximately constant curvature in the MDS-constructed 3D space. The gnarled pathway indicated that evolution on the trunk favored multiple substitutions at the same amino acid positions on HA. The constant curvature was reasonably explained by assuming that the rate of amino acid substitutions varied from one position to another according to a gamma distribution. Furthermore, we utilized the estimated parameters of the gamma distribution to predict the amino acid substitutions on HA in subsequent years. Retrospective prediction tests for 12 years from 1997 to 2009 showed that 70% of actual amino acid substitutions were correctly predicted, and that 45% of predicted amino acid substitutions have been actually observed. Although it remains unsolved how to predict the exact timing of antigenic changes, the present results suggest that our model may have the potential to recognize emerging epidemic strains.

  18. Modelling the spreading rate of controlled communicable epidemics through an entropy-based thermodynamic model

    CERN Document Server

    Wang, W B; Cao, Z M; Hu, R F

    2013-01-01

    A model based on a thermodynamic approach is proposed for predicting the dynamics of communicable epidemics in a city, when the epidemic is governed by controlling efforts of multiple scales so that an entropy is associated with the system. All the epidemic details are factored into a single parameter that is determined by maximizing the rate of entropy production. Despite the simplicity of the final model, it predicts the number of hospitalized cases with a reasonable accuracy, using the data of SARS of the year 2003, once the inflexion point characterizing the effect of multiple controlling efforts is known. This model is supposed to be of potential usefulness since epidemics such as avian influenza like H7H9 in China this year have the risk to become communicable among human beings.

  19. PEMODELAN MATEMATIKA PADA EPIDEMI INFLUENZA DENGAN STRATEGI VAKSINASI

    Directory of Open Access Journals (Sweden)

    M Kharis

    2016-04-01

    Full Text Available Pada tahun 2009 merebak epidemi flu burung kemudian diikuti epidemi flu babi. Epidemi flu tersebut menyebabkan beberapa kasus kematian dan banyak manusia yang masuk ke rumah sakit. Salah satu usaha yang dilakukan untuk menanggulangi wabah ini adalah dengan melakukan vaksinasi. Vaksinasi dilakukan terhadap orang yang belum terkena influenza. Melihat fakta bahwa penyakit ini bersifat epidemik, maka sangat dimungkinkan untuk membentuk model matematika dari kasus influenza tersebut. Model yang dihasilkan berbentuk SIRS dengan populasi konstan. Dalam penelitian ini digunakan metode tinjauan pustaka, analisis, dan pembuatan simulasi. Simpulan yang diperoleh berupa model matematika dan analisanya serta nilai minimal persentase individu yang divaksinasi supaya wabah tidak meluas.In 2009,  bird flu epidemic outbreak and it is followed by swine flu epidemic. Flu epidemic causes many mortality in human and more of human must be treated in hospital. One of the efforts to combat this plague is vaccination. Vaccination was given to susceptible human. From the fact that the disease is epidemic, it is possible to establish a mathematical model of the influenza cases. The resulting model is SIRS with constant population. In this study, it was used methods include literature reviews, analysis, and simulation. The conclusions obtained in the form of mathematical models and analysis as well as the minimum percentage of individuals who are vaccinated so that the plague has not spread.

  20. Social deprivation and burden of influenza: Testing hypotheses and gaining insights from a simulation model for the spread of influenza.

    Science.gov (United States)

    Hyder, Ayaz; Leung, Brian

    2015-06-01

    Factors associated with the burden of influenza among vulnerable populations have mainly been identified using statistical methodologies. Complex simulation models provide mechanistic explanations, in terms of spatial heterogeneity and contact rates, while controlling other factors and may be used to better understand statistical patterns and, ultimately, design optimal population-level interventions. We extended a sophisticated simulation model, which was applied to forecast epidemics and validated for predictive ability, to identify mechanisms for the empirical relationship between social deprivation and the burden of influenza. Our modeled scenarios and associated epidemic metrics systematically assessed whether neighborhood composition and/or spatial arrangement could qualitatively replicate this empirical relationship. We further used the model to determine consequences of local-scale heterogeneities on larger scale disease spread. Our findings indicated that both neighborhood composition and spatial arrangement were critical to qualitatively match the empirical relationship of interest. Also, when social deprivation was fully included in the model, we observed lower age-based attack rates and greater delay in epidemic peak week in the most socially deprived neighborhoods. Insights from simulation models complement current understandings from statistical-based association studies. Additional insights from our study are: (1) heterogeneous spatial arrangement of neighborhoods is a necessary condition for simulating observed disparities in the burden of influenza and (2) unmeasured factors may lead to a better quantitative match between simulated and observed rate ratio in the burden of influenza between the most and least socially deprived populations.

  1. Social deprivation and burden of influenza: Testing hypotheses and gaining insights from a simulation model for the spread of influenza

    Directory of Open Access Journals (Sweden)

    Ayaz Hyder

    2015-06-01

    Full Text Available Factors associated with the burden of influenza among vulnerable populations have mainly been identified using statistical methodologies. Complex simulation models provide mechanistic explanations, in terms of spatial heterogeneity and contact rates, while controlling other factors and may be used to better understand statistical patterns and, ultimately, design optimal population-level interventions. We extended a sophisticated simulation model, which was applied to forecast epidemics and validated for predictive ability, to identify mechanisms for the empirical relationship between social deprivation and the burden of influenza. Our modeled scenarios and associated epidemic metrics systematically assessed whether neighborhood composition and/or spatial arrangement could qualitatively replicate this empirical relationship. We further used the model to determine consequences of local-scale heterogeneities on larger scale disease spread. Our findings indicated that both neighborhood composition and spatial arrangement were critical to qualitatively match the empirical relationship of interest. Also, when social deprivation was fully included in the model, we observed lower age-based attack rates and greater delay in epidemic peak week in the most socially deprived neighborhoods. Insights from simulation models complement current understandings from statistical-based association studies. Additional insights from our study are: (1 heterogeneous spatial arrangement of neighborhoods is a necessary condition for simulating observed disparities in the burden of influenza and (2 unmeasured factors may lead to a better quantitative match between simulated and observed rate ratio in the burden of influenza between the most and least socially deprived populations.

  2. Severe sensitivity loss in an influenza A molecular assay due to antigenic drift variants during the 2014/15 influenza season.

    Science.gov (United States)

    Overmeire, Yarah; Vanlaere, Elke; Hombrouck, Anneleen; De Beenhouwer, Hans; Simons, Guus; Brink, Antoinette; Van den Abeele, Anne-Marie; Verfaillie, Charlotte; Van Acker, Jos

    2016-05-01

    The 2014-2015 influenza season in Belgium was dominated by the circulation of 2 influenza A(H3N2) subgroups: 3C.2a and 3C.3b. Analysis of 166 nasopharyngeal aspirates, collected in patients with respiratory illness at the start of the epidemic season, showed a decreased sensitivity for the detection of influenza A(H3N2)/3C.2a using a commercially available multiplex assay. Gene sequencing of the matrix protein showed a point mutation (C163T) leading to a mismatch with the assay probes.

  3. siRNA for Influenza Therapy

    Science.gov (United States)

    Barik, Sailen

    2010-01-01

    Influenza virus is one of the most prevalent and ancient infections in humans. About a fifth of world’s population is infected by influenza virus annually, leading to high morbidity and mortality, particularly in infants, the elderly and the immunocompromised. In the US alone, influenza outbreaks lead to roughly 30,000 deaths each year. Current vaccines and anti-influenza drugs are of limited use due to high mutation rate of the virus and side effects. In recent years, RNA interference, triggered by synthetic short interfering RNA (siRNA), has rapidly evolved as a potent antiviral regimen. Properly designed siRNAs have been shown to function as potent inhibitors of influenza virus replication. The siRNAs outperform traditional small molecule antivirals in a number of areas, such as ease of design, modest cost, and fast turnaround. Although specificity and tissue delivery remain major bottlenecks in the clinical applications of RNAi in general, intranasal application of siRNA against respiratory viruses including, but not limited to influenza virus, has experienced significant success and optimism, which is reviewed here. PMID:21994689

  4. siRNA for Influenza Therapy

    Directory of Open Access Journals (Sweden)

    Sailen Barik

    2010-07-01

    Full Text Available Influenza virus is one of the most prevalent and ancient infections in humans. About a fifth of world's population is infected by influenza virus annually, leading to high morbidity and mortality, particularly in infants, the elderly and the immunocompromised. In the US alone, influenza outbreaks lead to roughly 30,000 deaths each year. Current vaccines and anti-influenza drugs are of limited use due to high mutation rate of the virus and side effects. In recent years, RNA interference, triggered by synthetic short interfering RNA (siRNA, has rapidly evolved as a potent antiviral regimen. Properly designed siRNAs have been shown to function as potent inhibitors of influenza virus replication. The siRNAs outperform traditional small molecule antivirals in a number of areas, such as ease of design, modest cost, and fast turnaround. Although specificity and tissue delivery remain major bottlenecks in the clinical applications of RNAi in general, intranasal application of siRNA against respiratory viruses including, but not limited to influenza virus, has experienced significant success and optimism, which is reviewed here.

  5. Effectiveness of 2010/2011 seasonal influenza vaccine in Ireland.

    LENUS (Irish Health Repository)

    Barret, A S

    2012-02-01

    We conducted a case-control study to estimate the 2010\\/2011 trivalent influenza vaccine effectiveness (TIVE) using the Irish general practitioners\\' influenza sentinel surveillance scheme. Cases were influenza-like illness (ILI) patients with laboratory-confirmed influenza. Controls were ILI patients who tested negative for influenza. Participating sentinel general practitioners (GP) collected swabs from patients presenting with ILI along with their vaccination history and other individual characteristics. The TIVE was computed as (1 - odds ratiofor vaccination) x100%. Of 60 sentinel GP practices, 22 expressed interest in participating in the study and 17 (28%) recruited at least one ILI patient. In the analysis, we included 106 cases and 85 controls. Seven controls (8.2%) and one influenza case (0.9%) had been vaccinated in 2010\\/2011. The estimated TIVE against any influenza subtype was 89.4% [95% CI: 13.8; 99.8%], suggesting a protective effect against GP-attended laboratory confirmed influenza. This study design could be used to monitor influenza vaccine effectiveness annually but sample size and vaccination coverage should be increased to obtain precise and adjusted estimates.

  6. Compounds with anti-influenza activity: present and future of strategies for the optimal treatment and management of influenza. Part II: Future compounds against influenza virus.

    Science.gov (United States)

    Gasparini, R; Amicizia, D; Lai, P L; Bragazzi, N L; Panatto, D

    2014-12-01

    In the first part of this overview, we described the life cycle of the influenza virus and the pharmacological action of the currently available drugs. This second part provides an overview of the molecular mechanisms and targets of still-experimental drugs for the treatment and management of influenza. Briefly, we can distinguish between compounds with anti-influenza activity that target influenza virus proteins or genes, and molecules that target host components that are essential for viral replication and propagation. These latter compounds have been developed quite recently. Among the first group, we will focus especially on hemagglutinin, M2 channel and neuraminidase inhibitors. The second group of compounds may pave the way for personalized treatment and influenza management. Combination therapies are also discussed. In recent decades, few antiviral molecules against influenza virus infections have been available; this has conditioned their use during human and animal outbreaks. Indeed, during seasonal and pandemic outbreaks, antiviral drugs have usually been administered in mono-therapy and, sometimes, in an uncontrolled manner to farm animals. This has led to the emergence of viral strains displaying resistance, especially to compounds of the amantadane family. For this reason, it is particularly important to develop new antiviral drugs against influenza viruses. Indeed, although vaccination is the most powerful means of mitigating the effects of influenza epidemics, antiviral drugs can be very useful, particularly in delaying the spread of new pandemic viruses, thereby enabling manufacturers to prepare large quantities of pandemic vaccine. In addition, antiviral drugs are particularly valuable in complicated cases of influenza, especially in hospitalized patients. To write this overview, we mined various databases, including Embase, PubChem, DrugBank and Chemical Abstracts Service, and patent repositories.

  7. Post-vaccine measles in a child with concomitant influenza, Sicily, Italy, March 2015.

    Science.gov (United States)

    Tramuto, F; Dones, P; D Angelo, C; Casuccio, N; Vitale, F

    2015-05-21

    We describe the occurrence of measles in an 18 month-old patient in Sicily, Italy, in March 2015, who received the first dose of a measles-containing vaccine seven days before onset of prodromal symptoms. Measles virus infection was confirmed by PCR and detection of specific immunoglobulin; viral genotyping permitted the confirmation of a vaccine-associated illness. The patient had a concurrent influenza virus infection, during a seasonal epidemic outbreak of influenza.

  8. 2009 H1N1 influenza virus infection and necrotizing pneumonia treated with extracorporeal membrane oxygenation

    Directory of Open Access Journals (Sweden)

    Suntae Ji

    2011-08-01

    Full Text Available A 3-year-old girl with acute respiratory distress syndrome due to a H1N1 2009 influenza virus infection was complicated by necrotizing pneumonia was successfully treated with extracorporeal membrane oxygenation (ECMO. This is the first reported case in which a pediatric patient was rescued with ECMO during the H1N1 influenza epidemic in Korea in 2009.

  9. Genetic Reassortment Among the Influenza Viruses (Avian Influenza, Human Influenza and Swine Influenza in Pigs

    Directory of Open Access Journals (Sweden)

    Dyah Ayu Hewajuli

    2012-12-01

    Full Text Available Influenza A virus is a hazardous virus and harm to respiratory tract. The virus infect birds, pigs, horses, dogs, mammals and humans. Pigs are important hosts in ecology of the influenza virus because they have two receptors, namely NeuAc 2,3Gal and NeuAc 2,6Gal which make the pigs are sensitive to infection of influenza virus from birds and humans and genetic reassortment can be occurred. Classical swine influenza H1N1 viruses had been circulated in pigs in North America and other countries for 80 years. In 1998, triple reassortant H3N2 swine influenza viruses that contains genes of human influenza A virus (H3N2, swine influenza virus (H1N1 and avian influenza are reported as cause an outbreaks in pigs in North America. Furthermore, the circulation of triple reassortant H3N2 swine influenza virus resulting reassortant H1N1 swine influenza and reassortant H1N2 swine influenza viruses cause infection in humans. Humans who were infected by triple reassortant swine influenza A virus (H1N1 usually made direct contact with pigs. Although without any clinical symptoms, pigs that are infected by triple reassortant swine influenza A (H1N1 can transmit infection to the humans around them. In June 2009, WHO declared that pandemic influenza of reassortant H1N1 influenza A virus (novel H1N1 has reached phase 6. In Indonesia until 2009, there were 1005 people were infected by H1N1 influenza A and 5 of them died. Novel H1N1 and H5N1 viruses have been circulated in humans and pigs in Indonesia. H5N1 reassortant and H1N1 viruses or the seasonal flu may could arise because of genetic reassortment between avian influenza and humans influenza viruses that infect pigs together.

  10. Uncomplicated Cystitis in an Adult Male Following Influenza B Virus Infection

    Science.gov (United States)

    Allen, Robert J.; Koutsakos, Marios; Hurt, Aeron C.; Kedzierska, Katherine

    2017-01-01

    Patient: Male, 31 Final Diagnosis: Uncomplicated cystitis Symptoms: Cough • dysuria • fever • hematuria Medication: — Clinical Procedure: — Specialty: Infectious Diseases Objective: Unusual clinical course Background: Influenza B viruses cause seasonal epidemics of respiratory illness, circulating concurrently with influenza A viruses. However, virological and clinical knowledge of influenza B viruses is less well advanced than for influenza A, and in particular, complications associated with influenza B infection are not as commonly reported. Complications of influenza B infection predominantly include neurological and musculoskeletal pathologies, while a review of the literature shows that bacterial infections associated with influenza B viruses often involve Gram-positive organisms, with a smaller subset featuring Gram-negative species. Case Report: In this case report we highlight an uncomplicated infection of the urinary tract by Escherichia coli immediately following influenza B infection, in an otherwise healthy adult white male with no prior history of urinary tract infection or structural abnormalities of the renal tract. Conclusions: Bacterial infections complicating influenza B infection may include organisms not commonly associated with the respiratory system, such as Escherichia coli. In addition, bacterial complications of influenza B infection may affect non-respiratory systems, including the genitourinary tract. PMID:28223680

  11. Contact transmission of influenza virus between ferrets imposes a looser bottleneck than respiratory droplet transmission allowing propagation of antiviral resistance

    Science.gov (United States)

    Frise, Rebecca; Bradley, Konrad; van Doremalen, Neeltje; Galiano, Monica; Elderfield, Ruth A.; Stilwell, Peter; Ashcroft, Jonathan W.; Fernandez-Alonso, Mirian; Miah, Shahjahan; Lackenby, Angie; Roberts, Kim L.; Donnelly, Christl A.; Barclay, Wendy S.

    2016-01-01

    Influenza viruses cause annual seasonal epidemics and occasional pandemics. It is important to elucidate the stringency of bottlenecks during transmission to shed light on mechanisms that underlie the evolution and propagation of antigenic drift, host range switching or drug resistance. The virus spreads between people by different routes, including through the air in droplets and aerosols, and by direct contact. By housing ferrets under different conditions, it is possible to mimic various routes of transmission. Here, we inoculated donor animals with a mixture of two viruses whose genomes differed by one or two reverse engineered synonymous mutations, and measured the transmission of the mixture to exposed sentinel animals. Transmission through the air imposed a tight bottleneck since most recipient animals became infected by only one virus. In contrast, a direct contact transmission chain propagated a mixture of viruses suggesting the dose transferred by this route was higher. From animals with a mixed infection of viruses that were resistant and sensitive to the antiviral drug oseltamivir, resistance was propagated through contact transmission but not by air. These data imply that transmission events with a looser bottleneck can propagate minority variants and may be an important route for influenza evolution. PMID:27430528

  12. Quantitative detection of Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae in patients with new influenza A (H1N1/2009 and influenza A/2010 virus infection

    Directory of Open Access Journals (Sweden)

    Safaeyan, Firouzeh

    2015-04-01

    Full Text Available Introduction: Viral influenza is a seasonal infection associated with significant morbidity and mortality. In the United States more than 35,000 deaths and 200,000 hospitalizations are recorded annually due to influenza. Secondary bacterial infections or co-infections associated with cases of influenza are a leading cause of severe morbidity and mortality, especially among high-risk groups such as the elderly and young children. Aim: The aim of the present study was the quantitative detection of and in a group of patients with seasonal influenza A, influenza A ( pandemic 2009, and patients with symptoms of respiratory infection, but the negative for serving as control group.Method: In total, 625 patients suspected respiratory infection from April 2009 to April 2010 were studied. There were 58 patients with influenza A and 567 patients negative for influenza A . From November 2010 to February 2011, 158 patients with respiratory symptoms were analyzed for seasonal influenza A. There were 25 patients with seasonal influenza A. To check the colonization status among the healthy individuals 62 healthy persons were further investigated. Individual were screened in parallel. The choices of special genes were amplified from clinical specimens using real-time PCR with a cutoff of 10 CFU/mL to differentiate colonization from infection in respiratory tract.Results: and were detected in 12%, 26% and 33% of patients with , while the corresponding figures were 9%, 19%, and 31% for negative patients. Among patients with seasonal influenza A 12% 24% , and 32% co-infections were detected, while influenza negative control group yielded 5% , 11% , and 10% , respectively. Conclusion: The results of this study indicated that the serotype of pandemic 2009 did not increase incidence of secondary infection with and . Quantitative detection of secondary bacterial infection by QR-PCR can help us for distinguishing colonization from infection and controlling misuse of

  13. Age Distribution of Influenza Like Illness Cases during Post-Pandemic A(H3N2): Comparison with the Twelve Previous Seasons, in France

    Science.gov (United States)

    Turbelin, Clément; Souty, Cécile; Pelat, Camille; Hanslik, Thomas; Sarazin, Marianne; Blanchon, Thierry; Falchi, Alessandra

    2013-01-01

    In France, the 2011–2012 influenza epidemic was characterized by the circulation of antigenically drifted influenza A(H3N2) viruses and by an increased disease severity and mortality among the elderly, with respect to the A(H1N1)pdm09 pandemic and post-pandemic outbreaks. Whether the epidemiology of influenza in France differed between the 2011–2012 epidemic and the previous outbreaks is unclear. Here, we analyse the age distribution of influenza like illness (ILI) cases attended in general practice during the 2011–2012 epidemic, and compare it with that of the twelve previous epidemic seasons. Influenza like illness data were obtained through a nationwide surveillance system based on sentinel general practitioners. Vaccine effectiveness was also estimated. The estimated number of ILI cases attended in general practice during the 2011–2012 was lower than that of the past twelve epidemics. The age distribution was characteristic of previous A(H3N2)-dominated outbreaks: school-age children were relatively spared compared to epidemics (co-)dominated by A(H1N1) and/or B viruses (including the 2009 pandemic and post-pandemic outbreaks), while the proportion of adults over 30 year-old was higher. The estimated vaccine effectiveness (54%, 95% CI (48, 60)) was in the lower range for A(H3N2) epidemics. In conclusion, the age distribution of ILI cases attended in general practice seems to be not different between the A(H3N2) pre-pandemic and post-pandemic epidemics. Future researches including a more important number of ILI epidemics and confirmed virological data of influenza and other respiratory pathogens are necessary to confirm these results. PMID:23755294

  14. Lactogenic immunity and vaccines for porcine epidemic diarrhea virus (PEDV): historical and current concepts

    Science.gov (United States)

    Morbidity, mortality, and loss of productivity from enteric diseases in neonatal piglets cost swine producers millions of dollars annually. In 2013-2014, the porcine epidemic diarrhea virus (PEDV) outbreak led to $900 million to $1.8 billion in annual losses to US swine producers. Passive lactogeni...

  15. Forecasting fluctuating outbreaks in seasonally driven epidemics

    Science.gov (United States)

    Stone, Lewi

    2009-03-01

    Seasonality is a driving force that has major impact on the spatio-temporal dynamics of natural systems and their populations. This is especially true for the transmission of common infectious diseases such as influenza, measles, chickenpox, and pertussis. Here we gain new insights into the nonlinear dynamics of recurrent diseases through the analysis of the classical seasonally forced SIR epidemic model. Despite many efforts over the last decades, it has been difficult to gain general analytical insights because of the complex synchronization effects that can evolve between the external forcing and the model's natural oscillations. The analysis advanced here attempts to make progress in this direction by focusing on the dynamics of ``skips'' where we identify and predict years in which the epidemic is absent rather than outbreak years. Skipping events are intrinsic to the forced SIR model when parameterised in the chaotic regime. In fact, it is difficult if not impossible to locate realistic chaotic parameter regimes in which outbreaks occur regularly each year. This contrasts with the well known Rossler oscillator whose outbreaks recur regularly but whose amplitude vary chaotically in time (Uniform Phase Chaotic Amplitude oscillations). The goal of the present study is to develop a ``language of skips'' that makes it possible to predict under what conditions the next outbreak is likely to occur, and how many ``skips'' might be expected after any given outbreak. We identify a new threshold effect and give clear analytical conditions that allow accurate predictions. Moreover, the time of occurrence (i.e., phase) of an outbreak proves to be a useful new parameter that carries important epidemiological information. In forced systems, seasonal changes can prevent late-initiating outbreaks (i.e., having high phase) from running to completion. These principles yield forecasting tools that should have relevance for the study of newly emerging and reemerging diseases.

  16. Progress toward the development of universal influenza vaccines.

    Science.gov (United States)

    Hoft, Daniel F; Belshe, Robert B

    2014-01-01

    Influenza remains a major problem causing significant morbidity and mortality annually and periodic pandemics with the potential for 10-100 fold increased mortality. Conventional vaccines can be highly effective if generated each year to match currently circulating viruses. Ongoing research focuses on producing cross-protective vaccines that induce T cell and/ or antibody responses specific for highly conserved viral epitopes. The Saint Louis University Center for Vaccine Development (SLUCVD) is highly engaged in multiple efforts to generate universally relevant influenza vaccines.

  17. About Haemophilus influenzae Disease

    Science.gov (United States)

    ... Hib Vaccination Hib Vaccination Meningitis Pneumonia Sepsis About Haemophilus influenzae Disease Recommend on Facebook Tweet Share Compartir H. ... severe, such as a bloodstream infection. Types of Haemophilus influenzae Infections Infections caused by these bacteria... Causes, How ...

  18. Influenza Vaccine, Live Intranasal

    Science.gov (United States)

    ... the recombinant influenza vaccine (RIV). The nasal spray flu vaccine (live attenuated influenza vaccine or LAIV) should NOT ... to your doctor or pharmacist about the best flu vaccine option for you or your family.

  19. Seasonal influenza vaccination for children in Thailand: a cost-effectiveness analysis.

    OpenAIRE

    Aronrag Meeyai; Naiyana Praditsitthikorn; Surachai Kotirum; Wantanee Kulpeng; Weerasak Putthasri; Cooper, Ben S.; Yot Teerawattananon

    2015-01-01

    Editors' Summary Background Every year, millions of people catch influenza, a viral disease of the airways. Most infected individuals recover quickly, but elderly people, the very young, and chronically ill individuals are at high risk of developing serious complications such as pneumonia; seasonal influenza kills about half a million people annually. Small but frequent changes in the influenza virus mean that an immune response produced one year by exposure to the virus provides only partial...

  20. Surveillance of influenza in Iceland during the 2009 pandemic.

    Science.gov (United States)

    Sigmundsdottir, G; Gudnason, T; Ólafsson, Ö; Baldvinsdottir, G E; Atladottir, A; Löve, A; Danon, L; Briem, H

    2010-12-09

    In a pandemic setting, surveillance is essential to monitor the spread of the disease and assess its impact. Appropriate mitigation and healthcare preparedness strategies depend on fast and accurate epidemic surveillance data. During the 2009 influenza A(H1N1) pandemic, rapid improvements in influenza surveillance were made in Iceland. Here, we describe the improvements made in influenza surveillance during the pandemic , which could also be of great value in outbreaks caused by other pathogens. Following the raised level of pandemic influenza alert in April 2009, influenza surveillance was intensified. A comprehensive automatic surveillance system for influenza-like illness was developed, surveillance of influenza-related deaths was established and laboratory surveillance for influenza was strengthened. School absenteeism reports were also collected and compared with results from the automatic surveillance system. The first case of 2009 pandemic influenza A(H1N1) was diagnosed in Iceland in May 2009, but sustained community transmission was not confirmed until mid-August. The pandemic virus circulated during the summer and early autumn before an abrupt increase in the number of cases was observed in October. There were large outbreaks in elementary schools for children aged 6–15 years throughout the country that peaked in late October. School absenteeism reports from all elementary schools in Iceland gave a similar epidemiological curve as that from data from the healthcare system. Estimates of the proportion of the population infected with the pandemic virus ranged from 10% to 22%. This study shows how the sudden need for improved surveillance in the pandemic led to rapid improvements in data collection in Iceland. This reporting system will be improved upon and expanded to include other notifiable diseases, to ensure accurate and timely collection of epidemiological data.

  1. The fast diagnosis by different methodologies of the influenza virus

    Directory of Open Access Journals (Sweden)

    Iris Hatibi

    2013-09-01

    Full Text Available This paper presents the causative agent of the epidemic of the influenza in our country during the season 2009-2010. It also shows the effectiveness of the molecular diagnosis for Influenza virus by the means of the real-time PCR method in comparative of classical virological ones. Also in this paper we have presented the antigenic characterization of this virus which caused the pandemic during 2009-2010 years. We have collected and processed with several diagnostic methods like imunoflorescent assay, rapid tests, isolation and molecular method 409 samples. These were collected by the means of a Sentinel Surveillance throughout Albania, (tampon nasal- pharyngeal from people suspected of influenza in different ages. To isolate the virus of influenza we have used two methods: the method of isolation of influenza in the cell line of MDCK and also the isolation of the viral RNA by the means of the molecular method. The identifications of the isolates were carried out through the reactions of the hem agglutination inhibition and we have used also the method of Immunofluorescence and rapid test for the antigen detection of influenza virus. The results of the virus analyses are given in the relevant figures. The positive isolates were sent to the International Center of Influenza in London to be confirmed and also to have a further genetic analysis through molecular methods. From these tests performed during the season 2009-2010, it came out that our country was affected by one strain of influenza type A, AH1N1 variant A/California/2009/11. This strain circulated in the whole world causing the pandemic of 2009 and was a new variant deriving from the fusion of 4 strains of Influenza a process which occurred in pigs. These variants have affected the majority of the countries in Europe and in the world.

  2. CURRENT APPROACHES TO UNIVERSAL VACCINE AGAINST INFLUENZA VIRUS

    Directory of Open Access Journals (Sweden)

    I. B. Esmagambetov

    2016-01-01

    Full Text Available Influenza is a seasonal infectious disease widespread across the globe. In Russia the share of influenza and other acute respiratory viral infections account for up to 90% of all infectious diseases. Scientific and reasonable method of influenza prevention is vaccination. However, traditional current influenza vaccines can’t induce protection against various virus strains that differ substantially in terms of their antigenic structure, and thus require periodic updates to its immunogenic components. In addition, there is the risk of a pandemic caused by an entirely new antigen in relation to variants of influenza virus A. Attempts to improve on traditional approaches to vaccination have focused primarily on improving production technologies and to increase immunogenicity of vaccines. Therefore, the urgent task is the creation of vaccines able to induce immune response a broad spectrum against different influenza virus strains and human strains of avian influenza, also can cause disease in humans. Protective effect of universal vaccine should be the induction of integrated immune response, based on the formulation of cross-reactive antibodies and T cells. The development of such universal vaccine could remove the need for periodical strain composition update of existing vaccines and, accor dingly, will be able to give the vaccine manufacturer itself, production planning regardless of epidemic seasons. Currently, the most widely studied antigens as key components of flu vaccines are proteins M2 and NP as well as the hemagglutinin of influenza virus. This review summarizes and lists some data of domestic and foreign research on a universal influenza virus vaccine.

  3. Role for proteases and HLA-G in the pathogenicity of influenza A viruses.

    Science.gov (United States)

    Foucault, Marie-Laure; Moules, Vincent; Rosa-Calatrava, Manuel; Riteau, Béatrice

    2011-07-01

    Influenza is one of the most common infectious diseases in humans occurring as seasonal epidemic and sporadic pandemic outbreaks. The ongoing infections of humans with avian H5N1 influenza A viruses (IAV) and the past 2009 pandemic caused by the quadruple human/avian/swine reassortant (H1N1) virus highlights the permanent threat caused by these viruses. This review aims to describe the interaction between the virus and the host, with a particular focus on the role of proteases and HLA-G in the pathogenicity of influenza viruses.

  4. Influenza and other respiratory viruses detected by influenza-like illness surveillance in Leyte Island, the Philippines, 2010-2013.

    Directory of Open Access Journals (Sweden)

    Hirono Otomaru

    Full Text Available This study aimed to determine the role of influenza-like illness (ILI surveillance conducted on Leyte Island, the Philippines, including involvement of other respiratory viruses, from 2010 to 2013. ILI surveillance was conducted from January 2010 to March 2013 with 3 sentinel sites located in Tacloban city, Palo and Tanauan of Leyte Island. ILI was defined as fever ≥38°C or feverish feeling and either cough or running nose in a patient of any age. Influenza virus and other 5 respiratory viruses were searched. A total of 5,550 ILI cases visited the 3 sites and specimens were collected from 2,031 (36.6% cases. Among the cases sampled, 1,637 (75.6% were children aged <5 years. 874 (43.0% cases were positive for at least one of the respiratory viruses tested. Influenza virus and respiratory syncytial virus (RSV were predominantly detected (both were 25.7% followed by human rhinovirus (HRV (17.5%. The age distributions were significantly different between those who were positive for influenza, HRV, and RSV. ILI cases were reported throughout the year and influenza virus was co-detected with those viruses on approximately half of the weeks of study period (RSV in 60.5% and HRV 47.4%. In terms of clinical manifestations, only the rates of headache and sore throat were significantly higher in influenza positive cases than cases positive to other viruses. In conclusion, syndromic ILI surveillance in this area is difficult to detect the start of influenza epidemic without laboratory confirmation which requires huge resources. Age was an important factor that affected positive rates of influenza and other respiratory viruses. Involvement of older age children may be useful to detect influenza more effectively.

  5. Anti-influenza activity of marchantins, macrocyclic bisbibenzyls contained in liverworts.

    Directory of Open Access Journals (Sweden)

    Yuma Iwai

    Full Text Available The H1N1 influenza A virus of swine-origin caused pandemics throughout the world in 2009 and the highly pathogenic H5N1 avian influenza virus has also caused epidemics in Southeast Asia in recent years. The threat of influenza A thus remains a serious global health issue and novel drugs that target these viruses are highly desirable. Influenza A possesses an endonuclease within its RNA polymerase which comprises PA, PB1 and PB2 subunits. To identify potential new anti-influenza compounds in our current study, we screened 33 different types of phytochemicals using a PA endonuclease inhibition assay in vitro and an anti-influenza A virus assay. The marchantins are macrocyclic bisbibenzyls found in liverworts, and plagiochin A and perrottetin F are marchantin-related phytochemicals. We found from our screen that marchantin A, B, E, plagiochin A and perrottetin F inhibit influenza PA endonuclease activity in vitro. These compounds have a 3,4-dihydroxyphenethyl group in common, indicating the importance of this moiety for the inhibition of PA endonuclease. Docking simulations of marchantin E with PA endonuclease suggest a putative "fitting and chelating model" as the mechanism underlying PA endonuclease inhibition. The docking amino acids are well conserved between influenza A and B. In a cultured cell system, marchantin E was further found to inhibit the growth of both H3N2 and H1N1 influenza A viruses, and marchantin A, E and perrotein F showed inhibitory properties towards the growth of influenza B. These marchantins also decreased the viral infectivity titer, with marchantin E showing the strongest activity in this assay. We additionally identified a chemical group that is conserved among different anti-influenza chemicals including marchantins, green tea catechins and dihydroxy phenethylphenylphthalimides. Our present results indicate that marchantins are candidate anti-influenza drugs and demonstrate the utility of the PA endonuclease assay in

  6. Matrix protein 2 of influenza A virus blocks autophagosome fusion with lysosomes

    DEFF Research Database (Denmark)

    Gannagé, Monique; Dormann, Dorothee; Albrecht, Randy;

    2009-01-01

    Influenza A virus is an important human pathogen causing significant morbidity and mortality every year and threatening the human population with epidemics and pandemics. Therefore, it is important to understand the biology of this virus to develop strategies to control its pathogenicity. Here, we...... demonstrate that influenza A virus inhibits macroautophagy, a cellular process known to be manipulated by diverse pathogens. Influenza A virus infection causes accumulation of autophagosomes by blocking their fusion with lysosomes, and one viral protein, matrix protein 2, is necessary and sufficient...... for this inhibition of autophagosome degradation. Macroautophagy inhibition by matrix protein 2 compromises survival of influenza virus-infected cells but does not influence viral replication. We propose that influenza A virus, which also encodes proapoptotic proteins, is able to determine the death of its host cell...

  7. 浙江省人感染H7N9禽流感疫情流行期间公众负面心理特征研究%The negative psychology for the public in Zhejiang province during the epidemic of human H7N9 avian influenza

    Institute of Scientific and Technical Information of China (English)

    张人杰; 姜婷婷; 李娜; 王臻; 刘碧瑶; 方乐; 张新卫

    2015-01-01

    .17)分](x2值分别为5.26、27.52、8.29,P值均<0.05);医务人员中,女性的抑郁、神经衰弱、恐惧、强迫-焦虑、疑病得分分别为0.33(0.00~0.67)、0.20(0.00~0.40)、0.50(0.17~0.83)、0.00(0.00~0.33)、0.00(0.00~0.50)分,高于男性[0.00(0.00~0.50)、0.00(0.00~0.40)、0.33(0.17~0.50)、0.00(0.00~0.17)、0.00(0.00~0.00)分](x2值分别为7.22、7.97、14.46、4.93、5.22,P值均<0.05);患者家属中,自评时心理状况不好的家属抑郁和神经衰弱得分分别为0.50(0.08~0.96)、0.30(0.00~0.55)分,高于心理状况好的家属[分别为0.17(0.00~0.83)、0.20(0.00~0.60)分](x2值分别为12.95、11.20,P值均<0.05).Spearman相关分析显示,调查对象风险感知程度与抑郁、神经衰弱、恐惧、疑病情绪均呈正相关,相关系数分别为0.07、0.07、0.08、0.04(P值均<0.05);风险应对水平与抑郁、神经衰弱、恐惧、强迫-焦虑、疑病均呈正相关,相关系数分别为0.09、0.09、0.12、0.05、0.04(P值均<0.05).结论 公众对人感染H7N9禽流感疫情的关注程度较高,存在一定程度疫情相关负面情绪,其中女性、年龄≥60岁、初中及以下文化程度、从事农业劳动、白评时身心健康状况不佳的人群负面情绪最为显著;公众风险感知和应对与抑郁、神经衰弱、恐惧、疑病均呈正相关.%Objective To evaluate the cognition and emotional response of the public in Zhejiang province during the epidemic of human H7N9 avian influenza and provide scientific support for group psychological intervention under public health emergency.Methods 57 communities in 19 counties from Hangzhou, Jiaxing and Lishui district of Zhejiang province were selected as survey sites using stratified clustered sampling method from March, 2013 to April, 2014.2 319 ordinary civilians were chosen using convenience sampling method and 390 individuals who had close contact history with H7N9 avian influenza patients, 109 family members

  8. A review of the indirect protection of younger children and the elderly through a mass influenza vaccination program in Japan.

    Science.gov (United States)

    Sugaya, Norio

    2014-12-01

    In the past, Japan's strategy for controlling influenza was to vaccinate schoolchildren based on the theory that this could reduce influenza epidemics in the community, and a special program to vaccinate schoolchildren against influenza was begun in 1962. However, the program was discontinued in 1994 because of lack of evidence that it had limited the spread of influenza in the community. In 2001, it was reported that a clear decrease in excess mortality had coincided with the timing of the schoolchild vaccination program. This decrease could have potentially occurred because elderly people were protected by herd immunity generated by the program. Moreover, the program protected the younger siblings of schoolchildren against influenza-associated encephalopathy. Finally, the program was effective in reducing the number of class cancellations and absenteeism from school. During the period when the program was in effect, Japanese schoolchildren served as a barrier against influenza in the community.

  9. Influenza A (H1N1)pnd09 Vaccination of Pregnant Women and Immunological Consequences for Their Offspring

    DEFF Research Database (Denmark)

    Bischoff, Anne Louise

    2013-01-01

    impact on neonatal immune signature in the airway of neonates implies that some immunological triggering factors during pregnancy may enhance changes in the immune system of the offspring. Influenza vaccination is generally considered safe for the pregnant mother and the fetus, but there is no published......Pregnant women experience increased influenza related morbidity and mortality during seasonal influenza epidemics, and even graver outcomes during influenza pandemics. Thus, even though the huge amount of data on clinical efficacy and effectiveness of influenza vaccine in pregnant women......, there is limited information on the details of the immunological responses to influenza immunization in pregnant versus non-pregnant. We had the unique opportunity to study the H1N1pnd09 vaccination of pregnant and non-pregnant women in our unselected, prospective, clinical pregnancy-cohort: the Copenhagen...

  10. Early detection of influenza like illness through medication sales.

    Science.gov (United States)

    Socan, Maja; Erculj, Vanja; Lajovic, Jaro

    2012-06-01

    Monitoring sales of medications is a potential candidate for an early signal of a seasonal influenza epidemic. To test this theory, the data from a traditional, consultation-oriented influenza surveillance system were compared to medication sales and a predictive model was developed. Weekly influenza-like incidence rates from the National Influenza Sentinel Surveillance System were compared to sales of seven groups of medications (nasal decongestants, medicines for sore throat (MST), antitussives, mucolytics, analgo-antipyretics, non-steroidal anti-inflamatory drugs (NSAIDs), betalactam antibiotics, and macrolide antibiotics) to determine the correlation of medication sales with the sentinel surveillance system - and therefore their predictive power. Poisson regression and regression tree approaches were used in the statistical analyses. The fact that NSAIDs do not exhibit any seasonality and that prescription of antibiotics requires a visit to the doctor's office makes the two medication groups inappropriate for predictive purposes. The influenza-like illness (ILI) curve is the best matched by the mucolytics and antitussives sales curves. Distinct seasonality is also observed with MST and decongestants. The model including these four medication groups performed best in prediction of ILI incidence rate using the Poisson regression model. Sales of antitussives proved to be the best single predictive variable for regression tree model. Sales of medication groups included in the model were demonstrated to have a predictive potential for early detection of influenza season. The quantitative information on medication sales proves to be a useful supplementary system, complementing the traditional consultation-oriented surveillance system.

  11. Psychosocial Correlates of Intention to Receive an Influenza Vaccination among Rural Adolescents

    Science.gov (United States)

    Painter, Julia E.; Sales, Jessica M.; Pazol, Karen; Wingood, Gina M.; Windle, Michael; Orenstein, Walter A.; Diclemente, Ralph J.

    2010-01-01

    The Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices recently expanded annual influenza vaccination recommendations to include all children 6 months through 18 years of age. Adolescent attitudes toward influenza vaccination may play a key role in reaching this newly added age group. This study examined the…

  12. School-Located Influenza Vaccination and Absenteeism among Elementary School Students in a Hispanic Community

    Science.gov (United States)

    Keck, Patricia C.; Ynalvez, Marcus Antonius; Gonzalez, Hector F.; Castillo, Keila D.

    2013-01-01

    Seasonal influenza is recognized as a significant health burden to children and is a cause of excess school absenteeism in children. In 2008, the Advisory Committee on Immunization Practices recommended annual influenza vaccination for all children 6 months to 18 years of age. School nurses influence participation in this recommendation by…

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

    Institute of Scientific and Technical Information of China (English)

    Naoyoshi; Maeda; Toshimitsu; Uede

    2010-01-01

    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.

  14. Live attenuated influenza vaccine--a review.

    Science.gov (United States)

    Gasparini, R; Amicizia, D; Lai, P L; Panatto, D

    2011-09-01

    Owing to the variability of influenza viruses, vaccine composition needs to be up-dated annually. As many variables can influence their efficacy, vaccines are still considered "sub-optimal". Many studies have been carried out in recent years to improve vaccines. In particular, researchers and vaccine-producing corporations have focused on developing a live vaccine. Among the candidate vaccines, the strain developed by Maassab has recently been licensed in the USA and Europe, after extensive investigation. This vaccine is safe and well tolerated, and has shown very good genetic stability. Although vaccine recipients are able to spread the virus, transmission to close contacts is practically non-existent. Studies on cold-adapted attenuated influenza vaccines have demonstrated that such vaccines are effective, and sometimes more effective than inactivated influenza vaccines. Cold-adapted attenuated influenza vaccines therefore appear to be an important weapon against influenza. However, a more widespread use of these vaccines is to be recommended, especially in children, as the more acceptable way of administration can favour parental compliance.

  15. Broadly cross-reactive antibodies dominate the human B cell response against 2009 pandemic H1N1 influenza virus infection

    OpenAIRE

    2011-01-01

    The 2009 pandemic H1N1 influenza pandemic demonstrated the global health threat of reassortant influenza strains. Herein, we report a detailed analysis of plasmablast and monoclonal antibody responses induced by pandemic H1N1 infection in humans. Unlike antibodies elicited by annual influenza vaccinations, most neutralizing antibodies induced by pandemic H1N1 infection were broadly cross-reactive against epitopes in the hemagglutinin (HA) stalk and head domain of multiple influenza strains. T...

  16. Leveraging social networks for understanding the evolution of epidemics

    Directory of Open Access Journals (Sweden)

    Martín Gonzalo

    2011-12-01

    Full Text Available Abstract Background To understand how infectious agents disseminate throughout a population it is essential to capture the social model in a realistic manner. This paper presents a novel approach to modeling the propagation of the influenza virus throughout a realistic interconnection network based on actual individual interactions which we extract from online social networks. The advantage is that these networks can be extracted from existing sources which faithfully record interactions between people in their natural environment. We additionally allow modeling the characteristics of each individual as well as customizing his daily interaction patterns by making them time-dependent. Our purpose is to understand how the infection spreads depending on the structure of the contact network and the individuals who introduce the infection in the population. This would help public health authorities to respond more efficiently to epidemics. Results We implement a scalable, fully distributed simulator and validate the epidemic model by comparing the simulation results against the data in the 2004-2005 New York State Department of Health Report (NYSDOH, with similar temporal distribution results for the number of infected individuals. We analyze the impact of different types of connection models on the virus propagation. Lastly, we analyze and compare the effects of adopting several different vaccination policies, some of them based on individual characteristics -such as age- while others targeting the super-connectors in the social model. Conclusions This paper presents an approach to modeling the propagation of the influenza virus via a realistic social model based on actual individual interactions extracted from online social networks. We implemented a scalable, fully distributed simulator and we analyzed both the dissemination of the infection and the effect of different vaccination policies on the progress of the epidemics. The epidemic values

  17. Epidemic dynamics on complex networks

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tao; FU Zhongqian; WANG Binghong

    2006-01-01

    Recently, motivated by the pioneer work in revealing the small-world effect and scale-free property of various real-life networks, many scientists devote themselves to studying complex networks. One of the ultimate goals is to understand how the topological structures affect the dynamics upon networks. In this paper, we give a brief review on the studies of epidemic dynamics on complex networks, including the description of classical epidemic models, the epidemic spread on small-world and scale-free networks, and network immunization. Finally, perspectives and some interesting problems are proposed.

  18. Epidemic Diffusion on Complex Networks

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-Yan; LIU Zong-Hua

    2007-01-01

    Boyh diffusion and epidemic are well studied in the stochastic systems and complex networks,respetively.Here we combine these two fields and study epidemic diffusion in complex networks.Instead of studying the threshold of infection,which was focused on in previous works,we focus on the diffusion.behaviour.We find that the epidemic diffusion in a complex network is an anomalous superdiffusion with varyingg diffusion exponext γand that γ is influenced seriously by the network structure,such as the clustering coefficient and the degree distribution.Numerical simulations have confirmed the theoretical predictions.

  19. Stochastic epidemic models: a survey

    CERN Document Server

    Britton, Tom

    2009-01-01

    This paper is a survey paper on stochastic epidemic models. A simple stochastic epidemic model is defined and exact and asymptotic model properties (relying on a large community) are presented. The purpose of modelling is illustrated by studying effects of vaccination and also in terms of inference procedures for important parameters, such as the basic reproduction number and the critical vaccination coverage. Several generalizations towards realism, e.g. multitype and household epidemic models, are also presented, as is a model for endemic diseases.

  20. Detecting signals of seasonal influenza severity through age dynamics

    DEFF Research Database (Denmark)

    Lee, Elizabeth C.; Viboud, Cécile; Simonsen, Lone

    2015-01-01

    seasons, and four states were identified as possible early warning sentinels for national severity. CONCLUSIONS: Differences in age patterns of ILI may be used to characterize seasonal influenza severity in the United States in real-time and in a spatially resolved way. Future research on antigenic......' severity benchmark that synthesizes multiple traditional severity indicators from publicly available influenza surveillance data in the United States. Observing that the age distribution of cases may signal severity early in an epidemic, we constructed novel retrospective and early warning severity indexes...... stages of an outbreak. To address the limitations of traditional indicators, we propose a novel severity index based on influenza age dynamics estimated from routine physician diagnosis data that can be used retrospectively and for early warning. METHODS: We developed a quantitative 'ground truth...

  1. [Polymorphism of current human influenza A and B virus population].

    Science.gov (United States)

    Grinbaum, E B; Litvinova, O M; Bannikov, A I; Konovalenko, I B; Chernookaia, N Iu; Iukhnova, L G; Kiselev, O I

    1994-01-01

    During the past years, the etiological situation has been significantly complicated. It is characterized by simultaneous circulation of A(H1N1), A(H3N2) and influenza B viruses and by the isolation of reassortant strains and viruses, which are atypical in relation to the process of their natural variability. The antigenic properties of epidemic strains and unusual isolates were investigated. The marked heterogeneity of the A(H3N2) influenza viruses was demonstrated. It was determined by the circulation of several antigenic variants during the epidemic. Two separate antigenic lineage of the influenza B viruses--b/Victoria/2/87 and B/Yamagata/16/88--cocirculated in our country in 1991. Since 1986, all the influenza A(H1N1) viruses have been considered to be varieties of the reference strain A/Taiwan/1/86. A direct correlation was found between some atypical viruses and the vaccine strains previously used.

  2. The problem of the periodicity of the epidemic process. [solar activity effects on diphtheria outbreak

    Science.gov (United States)

    Yagodinskiy, V. N.; Konovalenko, Z. P.; Druzhinin, I. P.

    1974-01-01

    An analysis of data from epidemics makes it possible to determine their principal causes, governed by environmental factors (solar activity, etc.) The results of an analysis of the periodicity of the epidemic process in the case of diphtheria are presented which was conducted with the aid of autocorrelation and spectral methods of analysis. Numerical data (annual figures) are used on the dynamics of diphtheria in 50 regions (points) with a total duration of 2,777 years.

  3. Avian influenza trasnmission risks: analysis of biosecuritiy measures and contact structure in Dutch poultry farming

    NARCIS (Netherlands)

    Ssematimba, A.; Hagenaars, T.H.J.; Wit, de J.J.; Ruiterkamp, F.; Fabri, T.H.F.; Stegeman, J.A.; Jong, de M.C.M.

    2013-01-01

    In the 2003 epidemic of highly pathogenic avian influenza in Dutch poultry, between-farm virus transmission continued for considerable time despite control measures. Gaining more insight into the mechanisms of this spread is necessary for the possible development of better control strategies. We car

  4. Cost effectiveness of vaccination against pandemic influenza in European countries : mathematical modelling analysis

    NARCIS (Netherlands)

    Lugner, A.K.; van Boven, Michiel; de Vries, Robin; Postma, M.J.; Wallinga, J.

    2012-01-01

    Objective To investigate whether a single optimal vaccination strategy exists across countries to deal with a future influenza pandemic by comparing the cost effectiveness of different strategies in various pandemic scenarios for three European countries. Design Economic and epidemic modelling study

  5. [Comparative study of genomes of present-day influenza A and B viruses].

    Science.gov (United States)

    Iukhnova, L G; Bannikov, A I; Grinbaum, E B

    1995-01-01

    The electrophoretic mobility of RNA fragments was used to study epidemic influenza viruses A and B as compared with the reference strains and virological findings. Among those tested, there was a further drift involving both the genes coding glycosylated proteins and internal and non-structural proteins. The analysis of atypical isolates showed their reassortant nature.

  6. How to develop a program to increase influenza vaccine uptake among workers in health care settings?

    NARCIS (Netherlands)

    Looijmans-van den Akker, I.; Hulscher, M.E.; Verheij, T.J.M.; Riphagen-Dalhuisen, J.; van Delden, J.J.M.; Hak, E.

    2011-01-01

    Background: Apart from direct protection and reduced productivity loss during epidemics, the main reason to immunize healthcare workers (HCWs) against influenza is to provide indirect protection of frail patients through reduced transmission in healthcare settings. Because the vaccine uptake among H

  7. How to develop a program to increase influenza vaccine uptake among workers in health care settings?

    NARCIS (Netherlands)

    Looijmans-van den Akker, I.; Hulscher, M.E.J.L.; Verheij, T.J.; Riphagen-Dalhuisen, J.; Delden, J.J.M. van; Hak, E.

    2011-01-01

    BACKGROUND: Apart from direct protection and reduced productivity loss during epidemics, the main reason to immunize healthcare workers (HCWs) against influenza is to provide indirect protection of frail patients through reduced transmission in healthcare settings. Because the vaccine uptake among H

  8. A onipresença do medo na influenza de 1918 Omnipotent fear along 1918 influenza

    Directory of Open Access Journals (Sweden)

    Liane Maria Bertucci

    2009-12-01

    Full Text Available O medo é um sentimento de diversas faces que durante a vigência de uma grave epidemia torna-se onipresente, podendo motivar tanto a discriminação e a exclusão, quanto a procura desesperada, e muitas vezes solidária, pela cura da doençaMoléstia que desafiou o saber médico-científico, a epidemia de influenza espanhola fez aflorar entre os brasileiros o medo do contato com o outro, a indiferença das pessoas e o temor ancestral dos hospitaisMas, o medo da gripe de 1918 motivou também a solidariedade, expressa de maneira singular na divulgação de práticas caseiras de cura que, combinadas com esparsas informações médicas e com a fé, traduziram a generosidade de indivíduos que difundiam gratuitamente aquilo que, acreditavam, poderia acabar com a epidemia.Fear is a multiple faces feeling that along a hard epidemic becomes omnipresent, as well as it can motivate discrimination and exclusion together to desperate, and many times solidary, search for disease cureA disease that challenged medical-scientific knowledge, influenza epidemic brought up among Brazilians fear of personal contact, as well as people unconcerning and ancestral terror of hospitalsOn the other hand, 1918 influenza fear motivated solidarity, which had been expressed in a singular manner on domestic healing practices that, joint together few medical information and faith, revealed generosity of individuals who broadcast for free those information that, they believed, could put an end to the epidemic.

  9. The new epidemic.

    Science.gov (United States)

    Allen, Jeanne V; Mellin, Grace C

    2014-03-01

    Editor's note: From its first issue in 1900 through to the present day, AJN has unparalleled archives detailing nurses' work and lives over the last century. These articles not only chronicle nursing's growth as a profession within the context of the events of the day, but they also reveal prevailing societal attitudes about women, health care, and human rights. Today's nursing school curricula rarely include nursing's history, but it's a history worth knowing. To this end, From the AJN Archives will be a frequent column, containing articles selected to fit today's topics and times.This month's article, from the November 1982 issue, is the first AJN article published on AIDS. It was early in the epidemic; only 608 cases of Kaposi's sarcoma and opportunistic infections had been reported to the Centers for Disease Control and Prevention-a mere trickle in the flood that was to come. Reading it now, aware of all we've learned since, we have a sense of how much we were fumbling around in the dark in those early days, searching for a cause and a cure, often going in wrong directions. The closest we had come to the true nature of the syndrome was an understanding that "life-style factors seem to be involved and the agent appears to be infectious." To read the complete article from our archives, go to http://bit.ly/1iswhZe.

  10. [Epidemic parotiditis, a reportable disease].

    Science.gov (United States)

    Boverhoff, J C; Baart, J A

    2013-01-01

    Three consecutive patients with an acute swelling of one of the cheeks, were diagnosed with epidemic parotiditis. The first phase of the diagnostic procedure for an acute cheek swelling is to eliminate the possibility of odontogenic causes. When odontogenic problems have been excluded, non-dentition-related causes may be considered. An acute, progressive swelling in the preauricular area can often be attributed to an inflammation of the parotid gland, but epidemic parotiditis should also be considered. Epidemic parotiditis, or mumps, is caused by the mumps virus. Contamination occurs aerogenically. In the Netherlands, mumps vaccine is an ingredient of the governmental combined mump-measles-rubella inoculation programme. However, in recent years several small-scale parotiditis epidemics have broken out, predominantly among young, inoculated adults. Oropharyngeal mucus and blood samples are needed to diagnose the disease. Each case of the disease should be reported to the community healthcare service.

  11. Epidemic cholera spreads like wildfire

    Science.gov (United States)

    Roy, Manojit; Zinck, Richard D.; Bouma, Menno J.; Pascual, Mercedes

    2014-01-01

    Cholera is on the rise globally, especially epidemic cholera which is characterized by intermittent and unpredictable outbreaks that punctuate periods of regional disease fade-out. These epidemic dynamics remain however poorly understood. Here we examine records for epidemic cholera over both contemporary and historical timelines, from Africa (1990-2006) and former British India (1882-1939). We find that the frequency distribution of outbreak size is fat-tailed, scaling approximately as a power-law. This pattern which shows strong parallels with wildfires is incompatible with existing cholera models developed for endemic regions, as it implies a fundamental role for stochastic transmission and local depletion of susceptible hosts. Application of a recently developed forest-fire model indicates that epidemic cholera dynamics are located above a critical phase transition and propagate in similar ways to aggressive wildfires. These findings have implications for the effectiveness of control measures and the mechanisms that ultimately limit the size of outbreaks.

  12. Epidemic Network Failures in Optical Transport Networks

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Katsikas, Dimitrios; Fagertun, Anna Manolova

    2013-01-01

    This paper presents a failure propagation model for transport networks which are affected by epidemic failures. The network is controlled using the GMPLS protocol suite. The Susceptible Infected Disabled (SID) epidemic model is investigated and new signaling functionality of GMPLS to support...... epidemic failure resolution is proposed. The results provide important input to service recovery mechanisms under epidemic failures....

  13. Earthquakes, influenza and cycles of Indian kala-azar.

    Science.gov (United States)

    Dye, C; Wolpert, D M

    1988-01-01

    It is suggested that previous data indicate 3 major epidemics of kala-azar in Assam between 1875 and 1950, with inter-epidemic periods of 30-45 and 20 years. This deviates from the popular view of regular cycles with a 10-20 year period. A deterministic mathematical model of kala-azar is used to find the simplest explanation for the timing of the 3 epidemics, paying particular attention to the role of extrinsic (drugs, natural disasters, other infectious diseases) versus intrinsic (host and vector dynamics, birth and death rates, immunity) processes in provoking the second. We conclude that, whilst widespread influenza in 1918-1919 may have magnified the second epidemic, intrinsic population processes provide the simplest explanation for its timing and synchrony throughout Assam. The model also shows that the second inter-epidemic period is expected to be shorter than the first, even in the absence of extrinsic agents, and highlights the importance of a small fraction of patients becoming chronically infectious (with post kala-azar dermal leishmaniasis) after treatment during an epidemic.

  14. Skip the trip: air travelers' behavioral responses to pandemic influenza.

    Directory of Open Access Journals (Sweden)

    Eli P Fenichel

    Full Text Available Theory suggests that human behavior has implications for disease spread. We examine the hypothesis that individuals engage in voluntary defensive behavior during an epidemic. We estimate the number of passengers missing previously purchased flights as a function of concern for swine flu or A/H1N1 influenza using 1.7 million detailed flight records, Google Trends, and the World Health Organization's FluNet data. We estimate that concern over "swine flu," as measured by Google Trends, accounted for 0.34% of missed flights during the epidemic. The Google Trends data correlates strongly with media attention, but poorly (at times negatively with reported cases in FluNet. Passengers show no response to reported cases. Passengers skipping their purchased trips forwent at least $50 M in travel related benefits. Responding to actual cases would have cut this estimate in half. Thus, people appear to respond to an epidemic by voluntarily engaging in self-protection behavior, but this behavior may not be responsive to objective measures of risk. Clearer risk communication could substantially reduce epidemic costs. People undertaking costly risk reduction behavior, for example, forgoing nonrefundable flights, suggests they may also make less costly behavior adjustments to avoid infection. Accounting for defensive behaviors may be important for forecasting epidemics, but linking behavior with epidemics likely requires consideration of risk communication.

  15. Real-time forecasts of dengue epidemics

    Science.gov (United States)

    Yamana, T. K.; Shaman, J. L.

    2015-12-01

    Dengue is a mosquito-borne viral disease prevalent in the tropics and subtropics, with an estimated 2.5 billion people at risk of transmission. In many areas with endemic dengue, disease transmission is seasonal but prone to high inter-annual variability with occasional severe epidemics. Predicting and preparing for periods of higher than average transmission is a significant public health challenge. Here we present a model of dengue transmission and a framework for optimizing model simulations with real-time observational data of dengue cases and environmental variables in order to generate ensemble-based forecasts of the timing and severity of disease outbreaks. The model-inference system is validated using synthetic data and dengue outbreak records. Retrospective forecasts are generated for a number of locations and the accuracy of these forecasts is quantified.

  16. Using an adjusted Serfling regression model to improve the early warning at the arrival of peak timing of influenza in Beijing.

    Directory of Open Access Journals (Sweden)

    Xiaoli Wang

    Full Text Available Serfling-type periodic regression models have been widely used to identify and analyse epidemic of influenza. In these approaches, the baseline is traditionally determined using cleaned historical non-epidemic data. However, we found that the previous exclusion of epidemic seasons was empirical, since year-year variations in the seasonal pattern of activity had been ignored. Therefore, excluding fixed 'epidemic' months did not seem reasonable. We made some adjustments in the rule of epidemic-period removal to avoid potentially subjective definition of the start and end of epidemic periods. We fitted the baseline iteratively. Firstly, we established a Serfling regression model based on the actual observations without any removals. After that, instead of manually excluding a predefined 'epidemic' period (the traditional method, we excluded observations which exceeded a calculated boundary. We then established Serfling regression once more using the cleaned data and excluded observations which exceeded a calculated boundary. We repeated this process until the R2 value stopped to increase. In addition, the definitions of the onset of influenza epidemic were heterogeneous, which might make it impossible to accurately evaluate the performance of alternative approaches. We then used this modified model to detect the peak timing of influenza instead of the onset of epidemic and compared this model with traditional Serfling models using observed weekly case counts of influenza-like illness (ILIs, in terms of sensitivity, specificity and lead time. A better performance was observed. In summary, we provide an adjusted Serfling model which may have improved performance over traditional models in early warning at arrival of peak timing of influenza.

  17. Using an adjusted Serfling regression model to improve the early warning at the arrival of peak timing of influenza in Beijing.

    Science.gov (United States)

    Wang, Xiaoli; Wu, Shuangsheng; MacIntyre, C Raina; Zhang, Hongbin; Shi, Weixian; Peng, Xiaomin; Duan, Wei; Yang, Peng; Zhang, Yi; Wang, Quanyi

    2015-01-01

    Serfling-type periodic regression models have been widely used to identify and analyse epidemic of influenza. In these approaches, the baseline is traditionally determined using cleaned historical non-epidemic data. However, we found that the previous exclusion of epidemic seasons was empirical, since year-year variations in the seasonal pattern of activity had been ignored. Therefore, excluding fixed 'epidemic' months did not seem reasonable. We made some adjustments in the rule of epidemic-period removal to avoid potentially subjective definition of the start and end of epidemic periods. We fitted the baseline iteratively. Firstly, we established a Serfling regression model based on the actual observations without any removals. After that, instead of manually excluding a predefined 'epidemic' period (the traditional method), we excluded observations which exceeded a calculated boundary. We then established Serfling regression once more using the cleaned data and excluded observations which exceeded a calculated boundary. We repeated this process until the R2 value stopped to increase. In addition, the definitions of the onset of influenza epidemic were heterogeneous, which might make it impossible to accurately evaluate the performance of alternative approaches. We then used this modified model to detect the peak timing of influenza instead of the onset of epidemic and compared this model with traditional Serfling models using observed weekly case counts of influenza-like illness (ILIs), in terms of sensitivity, specificity and lead time. A better performance was observed. In summary, we provide an adjusted Serfling model which may have improved performance over traditional models in early warning at arrival of peak timing of influenza.

  18. Epidemics and the politics of knowledge: contested narratives in Egypt's H1N1 response.

    Science.gov (United States)

    Leach, Melissa; Tadros, Mariz

    2014-01-01

    This article explores the politics of knowledge involved in understanding and responding to epidemics in an era of global health governance and biosecurity. It develops and applies an approach focused on how multiple, competing narratives about epidemics are constructed, mobilized and interact, and selectively justify pathways of intervention and response. A detailed ethnographic case study of national and local responses to H1N1 influenza, so-called swine flu, in Egypt reveals how global narratives were reworked by powerful actors in a particular political context, suppressing and delegitimizing the alternative narratives of the Zabaleen (Coptic Christian) people whose lives and livelihoods centered on raising pigs and working with them to control urban waste. The case study illustrates important ways in which geographies and politics of blame around epidemics emerge and are justified, their political contexts and consequences, and how they may feed back to shape the dynamics of disease itself.

  19. Ideas, institutions, and interests in the global governance of epidemics in Asia.

    Science.gov (United States)

    Yoon, Sungwon

    2010-07-01

    Recent policy debates provide mounting evidence that global governance of epidemics in Asia is evolving with the rise of new actors, agendas, and programs to address the transnational nature of public health emergencies. However, there have been relatively few studies that address the question of why certain public health approaches are preferred. Drawing on the case studies of severe acute respiratory syndrome and H5N1 avian influenza, this article sets out to answer 2 questions about global governance of epidemics in Asia: What set of ideas characterizes the form of global governance of epidemics in Asia? Why does it prevail while other alternatives fall by the wayside? The central argument in this article is that the global public health agenda and action by policy communities are not only shaped by empirical realities of public health but are also the result of the contending sets of interests and concerns.

  20. Epidemic spreading in complex networks

    Institute of Scientific and Technical Information of China (English)

    Jie ZHOU; Zong-hua LIU

    2008-01-01

    The study of epidemic spreading in complex networks is currently a hot topic and a large body of results have been achieved.In this paper,we briefly review our contributions to this field,which includes the underlying mechanism of rumor propagation,the epidemic spreading in community networks,the influence of varying topology,and the influence of mobility of agents.Also,some future directions are pointed out.

  1. Intranasal vaccination promotes detrimental Th17-mediated immunity against influenza infection.

    Directory of Open Access Journals (Sweden)

    Asher Maroof

    2014-01-01

    Full Text Available Influenza disease is a global health issue that causes significant morbidity and mortality through seasonal epidemics. Currently, inactivated influenza virus vaccines given intramuscularly or live attenuated influenza virus vaccines administered intranasally are the only approved options for vaccination against influenza virus in humans. We evaluated the efficacy of a synthetic toll-like receptor 4 agonist CRX-601 as an adjuvant for enhancing vaccine-induced protection against influenza infection. Intranasal administration of CRX-601 adjuvant combined with detergent split-influenza antigen (A/Uruguay/716/2007 (H3N2 generated strong local and systemic immunity against co-administered influenza antigens while exhibiting high efficacy against two heterotypic influenza challenges. Intranasal vaccination with CRX-601 adjuvanted vaccines promoted antigen-specific IgG and IgA antibody responses and the generation of polyfunctional antigen-specific Th17 cells (CD4(+IL-17A(+TNFα(+. Following challenge with influenza virus, vaccinated mice transiently exhibited increased weight loss and morbidity during early stages of disease but eventually controlled infection. This disease exacerbation following influenza infection in vaccinated mice was dependent on both the route of vaccination and the addition of the adjuvant. Neutralization of IL-17A confirmed a detrimental role for this cytokine during influenza infection. The expansion of vaccine-primed Th17 cells during influenza infection was also accompanied by an augmented lung neutrophilic response, which was partially responsible for mediating the increased morbidity. This discovery is of significance in the field of vaccinology, as it highlights the importance of both route of vaccination and adjuvant selection in vaccine development.

  2. Intranasal Vaccination Promotes Detrimental Th17-Mediated Immunity against Influenza Infection

    Science.gov (United States)

    Maroof, Asher; Yorgensen, Yvonne M.; Li, Yufeng; Evans, Jay T.

    2014-01-01

    Influenza disease is a global health issue that causes significant morbidity and mortality through seasonal epidemics. Currently, inactivated influenza virus vaccines given intramuscularly or live attenuated influenza virus vaccines administered intranasally are the only approved options for vaccination against influenza virus in humans. We evaluated the efficacy of a synthetic toll-like receptor 4 agonist CRX-601 as an adjuvant for enhancing vaccine-induced protection against influenza infection. Intranasal administration of CRX-601 adjuvant combined with detergent split-influenza antigen (A/Uruguay/716/2007 (H3N2)) generated strong local and systemic immunity against co-administered influenza antigens while exhibiting high efficacy against two heterotypic influenza challenges. Intranasal vaccination with CRX-601 adjuvanted vaccines promoted antigen-specific IgG and IgA antibody responses and the generation of polyfunctional antigen-specific Th17 cells (CD4+IL-17A+TNFα+). Following challenge with influenza virus, vaccinated mice transiently exhibited increased weight loss and morbidity during early stages of disease but eventually controlled infection. This disease exacerbation following influenza infection in vaccinated mice was dependent on both the route of vaccination and the addition of the adjuvant. Neutralization of IL-17A confirmed a detrimental role for this cytokine during influenza infection. The expansion of vaccine-primed Th17 cells during influenza infection was also accompanied by an augmented lung neutrophilic response, which was partially responsible for mediating the increased morbidity. This discovery is of significance in the field of vaccinology, as it highlights the importance of both route of vaccination and adjuvant selection in vaccine development PMID:24465206

  3. Influenza Prevention: Information for Travelers

    Science.gov (United States)

    ... and Flu Vaccines Vaccine Effectiveness Types of Flu Vaccine Flu Shot Quadrivalent Influenza Vaccine Intradermal Influenza (Flu) Vaccination ... Cell-Based Flu Vaccines Flublok Seasonal Influenza (Flu) Vaccine Flu Vaccination by Jet Injector Adjuvant Vaccine Vaccine Virus ...

  4. Pregnant Women and Influenza (Flu)

    Science.gov (United States)

    ... and Flu Vaccines Vaccine Effectiveness Types of Flu Vaccine Flu Shot Quadrivalent Influenza Vaccine Intradermal Influenza (Flu) Vaccination ... Cell-Based Flu Vaccines Flublok Seasonal Influenza (Flu) Vaccine Flu Vaccination by Jet Injector Adjuvant Vaccine Vaccine Virus ...

  5. Balancing immune protection and immune pathology by CD8+ T cell responses to influenza infection

    Directory of Open Access Journals (Sweden)

    Susu eDuan

    2016-02-01

    Full Text Available Influenza A virus (IAV is a significant human pathogen causing annual epidemics and periodic pandemics. CD8+ cytotoxic T lymphocyte (CTL-mediated immunity contributes to clearance of virus-infected cells; CTL immunity targeting the conserved internal proteins of IAVs is a key protection mechanism when neutralizing antibodies are absent during heterosubtypic IAV infection. However, CTL infiltration into the airways, their cytotoxicity, and the effects of produced pro-inflammatory cytokines can cause severe lung tissue injury, thereby contributing to immunopathology. Studies have discovered complicated and exquisite stimulatory and inhibitory mechanisms that regulate CTL magnitude and effector activities during IAV infection. Here, we review the state of knowledge on the roles of IAV-specific CTLs in immune protection and immunopathology during IAV infection in animal models, highlighting the key findings of various requirements and constraints regulating the balance of immune protection and pathology involved in CTL immunity. We also discuss the evidence of cross-reactive CTL immunity as a positive correlate of cross-subtype protection during secondary IAV infection in both animal and human studies. We argue that the effects of CTL immunity on protection and immunopathology depend on multiple layers of host and viral factors, including complex host mechanisms to regulate CTL magnitude and effector activity, the pathogenic nature of the IAV, the innate response milieu, and the host historical immune context of influenza infection. Future efforts are needed to further understand these key host and viral factors, especially to differentiate those that constrain optimally effective CTL anti-viral immunity from those necessary to restrain CTL-mediated nonspecific immunopathology in the various contexts of IAV infection, in order to develop better vaccination and therapeutic strategies for modifying protective CTL immunity.

  6. Growth patterns and scaling laws governing AIDS epidemic in Brazilian cities

    CERN Document Server

    Antonio, F J; Teixeira, J J V; Mendes, R S

    2014-01-01

    Brazil holds approximately 1/3 of population living infected with AIDS (acquired immunodeficiency syndrome) in Central and South Americas, and it was also the first developing country to implement a large-scale control and intervention program against AIDS epidemic. In this scenario, we investigate the temporal evolution and current status of the AIDS epidemic in Brazil. Specifically, we analyze records of annual absolute frequency of cases for more than 5000 cities for the first 33 years of the infection in Brazil. We found that (i) the annual absolute frequencies exhibit a logistic-type growth with an exponential regime in the first few years of the AIDS spreading; (ii) the actual reproduction number decaying as a power law; (iii) the distribution of the annual absolute frequencies among cities decays with a power law behavior; (iv) the annual absolute frequencies and the number of inhabitants have an allometric relationship; (v) the temporal evolution of the annual absolute frequencies have different profi...

  7. 流感分子病毒学研究进展%The Progress of Molecular Virology of Influenza

    Institute of Scientific and Technical Information of China (English)

    邵惠训

    2011-01-01

    The genome of influenza virus is composed of 8 RNA segments , and consists of eight fr8gments of RNA encoding 10 proteins ,including HA , NA, NP , PA , PB1 , PB2 , M1 , M2 , NS1 and NS2 . HA and NA are the Burface proteins . These protein spikes allow influenza to infect and demage cells and are what the immune system recognizes. HA spike allows the virus to bind to and enter cells. NA spike is used to escape the cell, destroying it in the procesa. There are 16 different HA subtypes ( H1-H16) . There are also 9 different NA aubtypea ( N1-N9) .The major reservoirs of influenza A in nature are wild ducks and other waterfowl. All of these HA and NA subtypes have been detected in waterfowl. Influenza replicates in the lung and in the gut of birda and the infection is normally asymptomatic,but epidemics of fatal influenza have occurred in turkeys and chickena, and H5NI vinis has caused fatal infection in a number of different bird species. Duck can excrete virus in fecea,infecting other ducks via contaminated water. Migratory ducks then spread the virus around the world. The viruses in birds are in stasis.Almost no difference in amino acid sequences of the various proteins are present in viruses separated by many decades,although the nucleic acid sequences encoding;these proteins do drift. This together with the fact that the viruse8 seldom cause disease in their avian reservoirs show that influenza in birds is ancient and the virus has adapted to its primary host. The gene segments of influenza A virus reassort readily during; mixed infection, and viruses with new combinations of genes arise frequendy. Newly arising reassortants can cause major epidemics of influenza when introduced binauons of genes give rise to viruses that are capable of epidemic apread in humans.Only three 8ubtype of HA ( H1,H2 , and H3) and two subtype of NA (N1 and N2) have been bound to date in epidemic strains of human influenza virus. Three influenza pandemics occurred during the last century

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

    @@ 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 (http://www.who.int/csr/don/2009_07_16/en/).

  9. An overview of the regulation of influenza vaccines in the United States.

    Science.gov (United States)

    Weir, Jerry P; Gruber, Marion F

    2016-09-01

    Influenza virus vaccines are unique among currently licensed viral vaccines. The vaccines designed to protect against seasonal influenza illness must be updated periodically in an effort to match the vaccine strain with currently circulating viruses, and the vaccine manufacturing timeline includes multiple, overlapping processes with a very limited amount of flexibility. In the United States (U.S.), over 150 million doses of seasonal trivalent and quadrivalent vaccine are produced annually, a mammoth effort, particularly in the context of a vaccine with components that usually change on a yearly basis. In addition, emergence of an influenza virus containing an HA subtype that has not recently circulated in humans is an ever present possibility. Recently, pandemic influenza vaccines have been licensed, and the pathways for licensure of pandemic vaccines and subsequent strain updating have been defined. Thus, there are formidable challenges for the regulation of currently licensed influenza vaccines, as well as for the regulation of influenza vaccines under development. This review describes the process of licensing influenza vaccines in the U.S., the process and steps involved in the annual updating of seasonal influenza vaccines, and some recent experiences and regulatory challenges faced in development and evaluation of novel influenza vaccines.

  10. The effect of age and recent influenza vaccination history on the immunogenicity and efficacy of 2009-10 seasonal trivalent inactivated influenza vaccination in children.

    Directory of Open Access Journals (Sweden)

    Sophia Ng

    Full Text Available BACKGROUND: There is some evidence that annual vaccination of trivalent inactivated influenza vaccine (TIV may lead to reduced vaccine immunogenicity but evidence is lacking on whether vaccine efficacy is affected by prior vaccination history. The efficacy of one dose of TIV in children 6-8 y of age against influenza B is uncertain. We examined whether immunogenicity and efficacy of influenza vaccination in school-age children varied by age and past vaccination history. METHODS AND FINDINGS: We conducted a randomized controlled trial of 2009-10 TIV. Influenza vaccination history in the two preceding years was recorded. Immunogenicity was assessed by comparison of HI titers before and one month after receipt of TIV/placebo. Subjects were followed up for 11 months with symptom diaries, and respiratory specimens were collected during acute respiratory illnesses to permit confirmation of influenza virus infections. We found that previous vaccination was associated with reduced antibody responses to TIV against seasonal A(H1N1 and A(H3N2 particularly in children 9-17 y of age, but increased antibody responses to the same lineage of influenza B virus in children 6-8 y of age. Serological responses to the influenza A vaccine viruses were high regardless of vaccination history. One dose of TIV appeared to be efficacious against confirmed influenza B in children 6-8 y of age regardless of vaccination history. CONCLUSIONS: Prior vaccination was associated with lower antibody titer rises following vaccination against seasonal influenza A vaccine viruses, but higher responses to influenza B among individuals primed with viruses from the same lineage in preceding years. In a year in which influenza B virus predominated, no impact of prior vaccination history was observed on vaccine efficacy against influenza B. The strains that circulated in the year of study did not allow us to study the effect of prior vaccination on vaccine efficacy against influenza A.

  11. Influenza A and B viruses in the population of Vojvodina, Serbia

    Directory of Open Access Journals (Sweden)

    Radovanov J.

    2014-01-01

    Full Text Available At present, two influenza A viruses, H1N1pdm09 and H3N2, along with influenza B virus co-circulate in the human population, causing endemic and seasonal epidemic acute febrile respiratory infections, sometimes with life-threatening complications. Detection of influenza viruses in nasopharyngeal swab samples was done by real-time RT-PCR. There were 60.2% (53/88 positive samples in 2010/11, 63.4% (52/82 in 2011/12, and 49.9% (184/369 in 2012/13. Among the positive patients, influenza A viruses were predominant during the first two seasons, while influenza B type was more active during 2012/13. Subtyping of influenza A positive samples revealed the presence of A (H1N1pdm09 in 2010/11, A (H3N2 in 2011/12, while in 2012/13, both subtypes were detected. The highest seroprevalence against influenza A was in the age-group 30-64, and against influenza B in adults aged 30-64 and >65. [Projekat Ministarstva nauke Republike Srbije, br. TR31084

  12. Influenza virus vaccination and kidney graft rejection: causality or coincidence

    Science.gov (United States)

    Fischer, Anne Sophie Lind; Møller, Bjarne Kuno; Krag, Søren; Jespersen, Bente

    2015-01-01

    Influenza can cause significant morbidity and mortality in renal transplant recipients especially with a high rate of lower respiratory disease. Annual influenza vaccination is therefore recommended to renal transplant recipients. We report the first three cases of acute kidney injury in renal transplant recipients following influenza vaccination that all led to graft loss. They all had different native diseases and were all vaccinated in the same season of 2009–10. The time span from vaccination to decline of kidney function is shorter than the time to diagnosis since the three patients only had blood tests every 3 months or when symptoms became severe. These reports do not justify a change of current recommendations regarding influenza vaccination in renal transplant recipients, but they support the continued attention and registration of vaccinations to monitor side effects. PMID:26034595

  13. Animal Epidemic Information Quantity of Willingness for Farmers to Report under the Risk of Avian Influenza---A Case Study on Broiler Farmers in China%禽流感风险下农户愿意上报的疫情信息数量--以全国肉鸡养殖户为例

    Institute of Scientific and Technical Information of China (English)

    黄泽颖; 王济民; 靳淑平

    2016-01-01

    疫情发生时间、地点、采取的控制措施、疑似染疫动物的种类、数量、同群的数量、免疫情况、病亡数量、临床症状、病理变化是养殖户发现禽流感疫情时,需要依法上报的10个重要信息。疫情防控效果取决于养殖户上报信息的充分性。为规范养殖户上报疫情行为,通过收集全国331个肉鸡养殖户的调查问卷发现,平均每个养殖户上报6个疫情信息,但愿意上报全部信息的养殖户仅27.79%。通过负二项回归模型研究发现,影响养殖户愿意上报疫情信息数量的因素很多,但养殖规模、防疫信息渠道、禽流感联防联控系统参与意愿正向且显著的影响因素。与预期不同的是,北方养殖户有意向上报更多的疫情信息。最后提出相应的政策建议。%Outbreak time and site epidemic,control measures taken,variety and quantity of animals infected with epidemic diseases,numbers of the same group,immunization state,numbers of deaths,clinical symptoms, pathological changes are the ten important information that farmers need to report in accordance to law and regula-tion if they found bird flu epidemics.Effect of epidemic prevention and control depends on the adequacy of infor-mation that willingness for farmers to report.In order to regulate behavior of reporting epidemics for farmers,it is found that each farmer would like to report 6 kinds of epidemics information on average but there were only 27.79%of farmers who preferred to report all kinds of information by collecting 331 questionnaires on broiler farmers.It is also found that there are many influencing factors on numbers of epidemics information which farmers would like to report but positive and significant influencing factors are breeding scale of farmers,information channels of epidem-ic prevention,participation willingness of the joint prevention and joint control system on bird flu.As not expected, the northern farmers have

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

    Science.gov (United States)

    Marangon, S; Cristalli, A; Busani, L

    2007-01-01

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

  15. Pandemic influenza: human rights, ethics and duty to treat.

    Science.gov (United States)

    Pahlman, I; Tohmo, H; Gylling, H

    2010-01-01

    The 2009 influenza A/H1N1 pandemic seems to be only moderately severe. In the future, a pandemic influenza with high lethality, such as the Spanish influenza in 1918-1919 or even worse, may emerge. In this kind of scenario, lethality rates ranging roughly from 2% to 30% have been proposed. Legal and ethical issues should be discussed before the incident. This article aims to highlight the legal, ethical and professional aspects that might be relevant to anaesthesiologists in the case of a high-lethality infectious disease such as a severe pandemic influenza. The epidemiology, the role of anaesthesiologists and possible threats to the profession and colleagueship within medical specialties relevant to anaesthesiologists are reviewed. During historical plague epidemics, some doctors have behaved like 'deserters'. However, during the Spanish influenza, physicians remained at their jobs, although many perished. In surveys, more than half of the health-care workers have reported their willingness to work in the case of severe pandemics. Physicians have the same human rights as all citizens: they have to be effectively protected against infectious disease. However, they have a duty to treat. Fair and responsible colleagueship among the diverse medical specialties should be promoted. Until disaster threatens humanity, volunteering to work during a pandemic might be the best way to ensure that physicians and other health-care workers stay at their workplace. Broad discussion in society is needed.

  16. Influenza Vaccination Coverage Among Health Care Personnel - United States, 2015-16 Influenza Season.

    Science.gov (United States)

    Black, Carla L; Yue, Xin; Ball, Sarah W; Donahue, Sara M A; Izrael, David; de Perio, Marie A; Laney, A Scott; Williams, Walter W; Lindley, Megan C; Graitcer, Samuel B; Lu, Peng-Jun; DiSogra, Charles; Devlin, Rebecca; Walker, Deborah K; Greby, Stacie M

    2016-09-30

    The Advisory Committee on Immunization Practices recommends annual influenza vaccination for all health care personnel to reduce influenza-related morbidity and mortality among both health care personnel and their patients (1-4). To estimate influenza vaccination coverage among U.S. health care personnel for the 2015-16 influenza season, CDC conducted an opt-in Internet panel survey of 2,258 health care personnel during March 28-April 14, 2016. Overall, 79.0% of survey participants reported receiving an influenza vaccination during the 2015-16 season, similar to the 77.3% coverage reported for the 2014-15 season (5). Coverage in long-term care settings increased by 5.3 percentage points compared with the previous season. Vaccination coverage continued to be higher among health care personnel working in hospitals (91.2%) and lower among health care personnel working in ambulatory (79.8%) and long-term care settings (69.2%). Coverage continued to be highest among physicians (95.6%) and lowest among assistants and aides (64.1%), and highest overall among health care personnel who were required by their employer to be vaccinated (96.5%). Among health care personnel working in settings where vaccination was neither required, promoted, nor offered onsite, vaccination coverage continued to be low (44.9%). An increased percentage of health care personnel reporting a vaccination requirement or onsite vaccination availability compared with earlier influenza seasons might have contributed to the overall increase in vaccination coverage during the past 6 influenza seasons.

  17. Seasonal influenza vaccine uptake in HSE-funded hospitals and nursing homes during the 2011/2012 influenza season.

    Science.gov (United States)

    O'Lorcain, P; Cotter, S; Hickey, L; O'Flanagan, D; Corcoran, B; O'Meara, M

    2014-03-01

    Annual seasonal influenza vaccine is recommended for all health care workers (HCWs) in Ireland. For the 2011/2012 influenza season, information was collected on influenza vaccination uptake among HCWs employed in Health Service Executive (HSE)-funded hospitals (primarily acute) and of nursing homes (NHs) and also among NH long-term and short-term respite care residents. Forty-five hospitals (80%) and 120 NHs (75%) provided uptake data. Nationally, influenza vaccine uptake among hospital employed HCWs was estimated to be 18% and 14% among HCWs in NHs; in NHs vaccine uptake among long-term care residents was estimated to 88%. These findings highlight the continued low uptake among HCWs of all categories and demonstrate the need for sustained measures to improve uptake rates.

  18. Third European Influenza Summit: organized by the European Scientific Working group on Influenza (ESWI).

    Science.gov (United States)

    McElhaney, Janet; Osterhaus, Ab

    2013-12-16

    On 2 May 2013, the European Scientific Working group on Influenza (ESWI) held its third influenza summit at the Institute of European Studies at the Free University of Brussels. ESWI brought together more than 90 representatives of organizations of healthcare providers, senior citizens, at-risk patients and public health authorities for a day of tailored lectures, Q&A sessions and networking. Since recent studies, surveys and reviews have shed new light on some of the most intriguing influenza issues, the Summit faculty translated the newest scientific data into practice. The first part of the Summit programme focused on the current flu status in Europe, paying special attention to the protection of pregnant women and the elderly as well as to the issues of vaccine safety and effectiveness. The programme continued to highlight future challenges and evolutions like novel antiviral drugs against influenza, improved flu vaccines and the prospect of a universal flu vaccine. The annual ESWI flu summits are the pinnacles of ESWI's efforts to bridge the gap between science and society. ESWI's members are convinced that the fight against influenza can only be won when all parties are well informed and ready to work together.

  19. Participatory Online Surveillance as a Supplementary Tool to Sentinel Doctors for Influenza-Like Illness Surveillance in Italy

    Science.gov (United States)

    Bella, Antonino; Rizzo, Caterina

    2017-01-01

    The monitoring of seasonal influenza yearly epidemics remains one of the main activity of national syndromic surveillance systems. The development of internet-based surveillance tools has brought an innovative approach to seasonal influenza surveillance by directly involving self-selected volunteers among the general population reporting their health status on a weekly basis throughout the flu season. In this paper, we explore how Influweb, an internet-based monitoring system for influenza surveillance, deployed in Italy since 2008 has performed during three years from 2012 to 2015 in comparison with data collected during the same period by the Italian sentinel doctors surveillance system. PMID:28076411

  20. Generation of influenza virus from avian cells infected by Salmonella carrying the viral genome.

    Directory of Open Access Journals (Sweden)

    Xiangmin Zhang

    Full Text Available Domestic poultry serve as intermediates for transmission of influenza A virus from the wild aquatic bird reservoir to humans, resulting in influenza outbreaks in poultry and potential epidemics/pandemics among human beings. To combat emerging avian influenza virus, an inexpensive, heat-stable, and orally administered influenza vaccine would be useful to vaccinate large commercial poultry flocks and even migratory birds. Our hypothesized vaccine is a recombinant attenuated bacterial strain able to mediate production of attenuated influenza virus in vivo to induce protective immunity against influenza. Here we report the feasibility and technical limitations toward such an ideal vaccine based on our exploratory study. Five 8-unit plasmids carrying a chloramphenicol resistance gene or free of an antibiotic resistance marker were constructed. Influenza virus was successfully generated in avian cells transfected by each of the plasmids. The Salmonella carrier was engineered to allow stable maintenance and conditional release of the 8-unit plasmid into the avian cells for recovery of influenza virus. Influenza A virus up to 10⁷ 50% tissue culture infective doses (TCID50/ml were recovered from 11 out of 26 co-cultures of chicken embryonic fibroblasts (CEF and Madin-Darby canine kidney (MDCK cells upon infection by the recombinant Salmonella carrying the 8-unit plasmid. Our data prove that a bacterial carrier can mediate generation of influenza virus by delivering its DNA cargoes into permissive host cells. Although we have made progress in developing this Salmonella influenza virus vaccine delivery system, further improvements are necessary to achieve efficient virus production, especially in vivo.

  1. Epidemic spreading by objective traveling

    Science.gov (United States)

    Tang, Ming; Liu, Zonghua; Li, Baowen

    2009-07-01

    A fundamental feature of agent traveling in social networks is that traveling is usually not a random walk but with a specific destination and goes through the shortest path from starting to destination. A serious consequence of the objective traveling is that it may result in a fast epidemic spreading, such as SARS etc. In this letter we present a reaction-traveling model to study how the objective traveling influences the epidemic spreading. We consider a random scale-free meta-population network with sub-population at each node. Through a SIS model we theoretically prove that near the threshold of epidemic outbreak, the objective traveling can significantly enhance the final infected population and the infected fraction at a node is proportional to its betweenness for the traveling agents and approximately proportional to its degree for the non-traveling agents. Numerical simulations have confirmed the theoretical predictions.

  2. Metapopulation epidemic models with heterogeneous mixing and travel behaviour

    CERN Document Server

    Apolloni, Andrea; Ramasco, Jose' J; Jensen, Pablo; Colizza, Vittoria

    2014-01-01

    The complex interplay between population movements in space and non-homogeneous mixing patterns have so far hindered the fundamental understanding of the conditions for spatial invasion through a general theoretical framework. To address this issue, we present an analytical modelling approach taking into account such interplay under general conditions of mobility and interactions, in the simplifying assumption of two population classes. We describe a spatially structured population with non-homogeneous mixing and travel behaviour through a multi-host stochastic epidemic metapopulation model. Different population partitions, mixing patterns and mobility structures are considered, along with a specific application for the study of the role of age partition in the early spread of the 2009 H1N1 pandemic influenza. We provide a complete mathematical formulation of the model and derive a semi-analytical expression of the threshold condition for global invasion of an emerging infectious disease in the metapopulation...

  3. Unspecified gastroenteritis illness and deaths in the elderly associated with norovirus epidemics.

    NARCIS (Netherlands)

    Asten, L. van; Siebenga, J.; Wijngaard, C. van den; Verheij, R.; Vliet, H. van; Kretzschmar, M.; Boshuizen, H.; Pelt, W. van; Koopmans, M.

    2011-01-01

    BACKGROUND: New variant strains of norovirus have emerged worldwide in recent years, evolving by mutation much like influenza viruses. These strains have been associated with a notable increase in the number of annual norovirus outbreaks. However, the impact of such increased norovirus activity on m

  4. Unspecified gastroenteritis illness and deaths in the elderly associated with norovirus epidemics

    NARCIS (Netherlands)

    Asten, van L.; Siebenga, J.; Wijngaard, van den C.; Verheij, R.; Vliet, van H.; Kretzschmar, M.; Boshuizen, H.C.; Pelt, van W.; Koopmans, M.

    2011-01-01

    Background: New variant strains of norovirus have emerged worldwide in recent years, evolving by mutation much like influenza viruses. These strains have been associated with a notable increase in the number of annual norovirus outbreaks. However, the impact of such increased norovirus activity on m

  5. A comparative analysis of influenza vaccination programs.

    Directory of Open Access Journals (Sweden)

    Shweta Bansal

    2006-10-01

    Full Text Available BACKGROUND: The threat of avian influenza and the 2004-2005 influenza vaccine supply shortage in the United States have sparked a debate about optimal vaccination strategies to reduce the burden of morbidity and mortality caused by the influenza virus. METHODS AND FINDINGS: We present a comparative analysis of two classes of suggested vaccination strategies: mortality-based strategies that target high-risk populations and morbidity-based strategies that target high-prevalence populations. Applying the methods of contact network epidemiology to a model of disease transmission in a large urban population, we assume that vaccine supplies are limited and then evaluate the efficacy of these strategies across a wide range of viral transmission rates and for two different age-specific mortality distributions. We find that the optimal strategy depends critically on the viral transmission level (reproductive rate of the virus: morbidity-based strategies outperform mortality-based strategies for moderately transmissible strains, while the reverse is true for highly transmissible strains. These results hold for a range of mortality rates reported for prior influenza epidemics and pandemics. Furthermore, we show that vaccination delays and multiple introductions of disease into the community have a more detrimental impact on morbidity-based strategies than mortality-based strategies. CONCLUSIONS: If public health officials have reasonable estimates of the viral transmission rate and the frequency of new introductions into the community prior to an outbreak, then these methods can guide the design of optimal vaccination priorities. When such information is unreliable or not available, as is often the case, this study recommends mortality-based vaccination priorities.

  6. The response of the Liguria Region (Italy) to the pandemic influenza virus A/H1N1sv.

    Science.gov (United States)

    Amicizia, D; Cremonesi, I; Carloni, R; Schiaffino, S

    2011-09-01

    Influenza is a cause of acute respiratory disease. It has a typical epidemic nature during the winter season, but may also assume a pandemic pattern when a completely new virus spreads among humans. Influenza places a heavy economic and healthcare burden on both the National Health Service and society. During the 2009/2010 influenza pandemic season, the Liguria Region drew upon the specific skills of the various sectors of the Department of Health and Social Services. In collaboration with the Department of Health Sciences of the University of Genova, the Regional Health Agency (RHA) and other public organizations, steps were taken to address the issues of technical and scientific updating and the coordination of all the departments of Local Healthcare Units in Liguria. The main activities conducted at the regional level provided an adequate response to the influenza pandemic. These activities focused on Local and National Influenza Surveillance Systems, the regional Pandemic Plan, vaccination strategies for seasonal and pandemic influenza, and the communication of data from monitoring programs (sentinel physicians--syndromic surveillance). The prevention of influenza transmission and containment of epidemics and pandemics require effective communication strategies that should target the whole population.

  7. Interim estimates of 2013-14 seasonal influenza vaccine effectiveness - United States, February 2014.

    Science.gov (United States)

    Flannery, Brendan; Thaker, Swathi N; Clippard, Jessie; Monto, Arnold S; Ohmit, Suzanne E; Zimmerman, Richard K; Nowalk, Mary Patricia; Gaglani, Manjusha; Jackson, Michael L; Jackson, Lisa A; Belongia, Edward A; McLean, Huong Q; Berman, LaShondra; Foust, Angie; Sessions, Wendy; Spencer, Sarah; Fry, Alicia M

    2014-02-21

    In the United States, annual vaccination against seasonal influenza is recommended for all persons aged ≥6 months. Each season since 2004-05, CDC has estimated the effectiveness of seasonal influenza vaccine to prevent influenza-associated, medically attended acute respiratory illness (ARI). This report uses data from 2,319 children and adults enrolled in the U.S. Influenza Vaccine Effectiveness (Flu VE) Network during December 2, 2013-January 23, 2014, to estimate an interim adjusted effectiveness of seasonal influenza vaccine for preventing laboratory-confirmed influenza virus infection associated with medically attended ARI. During this period, overall vaccine effectiveness (VE) (adjusted for study site, age, sex, race/ethnicity, self-rated health, and days from illness onset to enrollment) against influenza A and B virus infection associated with medically attended ARI was 61%. The influenza A (H1N1)pdm09 (pH1N1) virus that emerged to cause a pandemic in 2009 accounted for 98% of influenza viruses detected. VE was estimated to be 62% against pH1N1 virus infections and was similar across age groups. As of February 8, 2014, influenza activity remained elevated in the United States, the proportion of persons seeing their health-care provider for influenza-like illness was lower than in early January but remained above the national baseline, and activity still might be increasing in some parts of the country. CDC and the Advisory Committee on Immunization Practices routinely recommend that annual influenza vaccination efforts continue as long as influenza viruses are circulating. Persons aged ≥6 months who have not yet been vaccinated this season should be vaccinated. Antiviral medications are an important second line of defense to treat influenza illness and should be used as recommended among suspected or confirmed influenza patients, regardless of patient vaccination status. Early antiviral treatment is recommended for persons with suspected influenza with

  8. Global Mortality Impact of the 1957-1959 Influenza Pandemic

    DEFF Research Database (Denmark)

    Viboud, Cécile; Simonsen, Lone; Fuentes, Rodrigo

    2016-01-01

    BACKGROUND: Quantitative estimates of the global burden of the 1957 influenza pandemic are lacking. Here we fill this gap by modeling historical mortality statistics. METHODS: We used annual rates of age- and cause-specific deaths to estimate pandemic-related mortality in excess of background lev...

  9. Mortality from contact-related epidemics among indigenous populations in Greater Amazonia.

    Science.gov (United States)

    Walker, Robert S; Sattenspiel, Lisa; Hill, Kim R

    2015-09-10

    European expansion and contact with indigenous populations led to catastrophic depopulation primarily through the introduction of novel infectious diseases to which native peoples had limited exposure and immunity. In the Amazon Basin such contacts continue to occur with more than 50 isolated indigenous societies likely to make further contacts with the outside world in the near future. Ethnohistorical accounts are useful for quantifying trends in the severity and frequency of epidemics through time and may provide insight into the likely demographic consequences of future contacts. Here we compile information for 117 epidemics that affected 59 different indigenous societies in Greater Amazonia and caused over 11,000 deaths between 1875 and 2008, mostly (75%) from measles, influenza, and malaria. Results show that mortality rates from epidemics decline exponentially through time and, independently, with time since peaceful contact. The frequency of documented epidemics also decreases with time since contact. While previous work on virgin soil epidemics generally emphasizes the calamity of contacts, we focus instead on improvements through time. The prospects for better survivorship during future contacts are good provided modern health care procedures are implemented immediately.

  10. A data-driven model for influenza transmission incorporating media effects

    Science.gov (United States)

    Ross, Joshua V.

    2016-01-01

    Numerous studies have attempted to model the effect of mass media on the transmission of diseases such as influenza; however, quantitative data on media engagement has until recently been difficult to obtain. With the recent explosion of ‘big data’ coming from online social media and the like, large volumes of data on a population’s engagement with mass media during an epidemic are becoming available to researchers. In this study, we combine an online dataset comprising millions of shared messages relating to influenza with traditional surveillance data on flu activity to suggest a functional form for the relationship between the two. Using this data, we present a simple deterministic model for influenza dynamics incorporating media effects, and show that such a model helps explain the dynamics of historical influenza outbreaks. Furthermore, through model selection we show that the proposed media function fits historical data better than other media functions proposed in earlier studies. PMID:27853563

  11. A data-driven model for influenza transmission incorporating media effects.

    Science.gov (United States)

    Mitchell, Lewis; Ross, Joshua V

    2016-10-01

    Numerous studies have attempted to model the effect of mass media on the transmission of diseases such as influenza; however, quantitative data on media engagement has until recently been difficult to obtain. With the recent explosion of 'big data' coming from online social media and the like, large volumes of data on a population's engagement with mass media during an epidemic are becoming available to researchers. In this study, we combine an online dataset comprising millions of shared messages relating to influenza with traditional surveillance data on flu activity to suggest a functional form for the relationship between the two. Using this data, we present a simple deterministic model for influenza dynamics incorporating media effects, and show that such a model helps explain the dynamics of historical influenza outbreaks. Furthermore, through model selection we show that the proposed media function fits historical data better than other media functions proposed in earlier studies.

  12. Seasonal and pandemic influenza: the role of communication and preventive strategies.

    Science.gov (United States)

    Boccia, A; Di Thiene, D; De Giusti, M; La Torre, G

    2011-09-01

    Appropriate, timely, and data-driven health information is a very important issue in preventive strategies against influenza. Intuitively, a link between willingness to be vaccinated against seasonal influenza and against pandemic influenza exists, given the similarities in decision-making for this vaccine. International and national literature reviews suggest that progress has been made in order to incorporate and disseminate crisis risk communication principles into public health practice, as such investments in public health could be important for building capacity and practice which aid in the realization of countermeasures in response to a future pandemic and epidemic situation. This study emphasizes the lack of perception by Health Care Workers (HCWs) of the importance of being immunized against seasonal and pandemic influenza and the doubts concerning safety. In the future, particular efforts are needed during vaccination campaigns, to provide more information to HCWs and the general population regarding role and safety of such vaccines.

  13. The Demise of Poskanzer and Schwab's Influenza Theory on the Pathogenesis of Parkinson's Disease.

    Science.gov (United States)

    Estupinan, Danny; Nathoo, Sunina; Okun, Michael S

    2013-01-01

    In 1961, David C. Poskanzer and Robert S. Schwab presented a paper, "Studies in the epidemiology of Parkinson's disease predicting its disappearance as a major clinical entity by 1980." This paper introduced the hypothesis that Parkinson's disease was derived from a single aetiology, the influenza virus. We review the original Poskanzer and Schwab hypothesis that Parkinson's disease was based on the association between the 1918-19 influenza epidemic and the later observation of Parkinsonism in some influenza sufferers. We also further explore the prediction that Parkinson's disease would totally disappear as an entity once original influenza victims were all deceased. Current research has revealed that there are many potential causes and factors important in the occurrence of Parkinson's disease, postencephalitic Parkinsonism, and encephalitis lethargica. Poskanzer and Schwab presented a novel hypothesis; however, it was proven false by a combination of research and time.

  14. Multi-Omics Studies towards Novel Modulators of Influenza A Virus–Host Interaction

    Directory of Open Access Journals (Sweden)

    Sandra Söderholm

    2016-09-01

    Full Text Available Human influenza A viruses (IAVs cause global pandemics and epidemics. These viruses evolve rapidly, making current treatment options ineffective. To identify novel modulators of IAV–host interactions, we re-analyzed our recent transcriptomics, metabolomics, proteomics, phosphoproteomics, and genomics/virtual ligand screening data. We identified 713 potential modulators targeting 199 cellular and two viral proteins. Anti-influenza activity for 48 of them has been reported previously, whereas the antiviral efficacy of the 665 remains unknown. Studying anti-influenza efficacy and immuno/neuro-modulating properties of these compounds and their combinations as well as potential viral and host resistance to them may lead to the discovery of novel modulators of IAV–host interactions, which might be more effective than the currently available anti-influenza therapeutics.

  15. A data-driven model for influenza transmission incorporating media effects

    CERN Document Server

    Mitchell, Lewis

    2016-01-01

    Numerous studies have attempted to model the effect of mass media on the transmission of diseases such as influenza, however quantitative data on media engagement has until recently been difficult to obtain. With the recent explosion of "big data" coming from online social media and the like, large volumes of data on a population's engagement with mass media during an epidemic are becoming available to researchers. In this study we combine an online data set comprising millions of shared messages relating to influenza with traditional surveillance data on flu activity to suggest a functional form for the relationship between the two. Using this data we present a simple deterministic model for influenza dynamics incorporating media effects, and show that such a model helps explain the dynamics of historical influenza outbreaks. Furthermore, through model selection we show that the proposed media function fits historical data better than other media functions proposed in earlier studies.

  16. Nephrotic Syndrome Following H1N1 Influenza in a 3-Year-Old Boy

    Directory of Open Access Journals (Sweden)

    Pio Liberatore

    2012-06-01

    Full Text Available Background: The pandemic influenza A/H1N1, spread through the world in 2009, producing a serious epidemic in Italy. Complications are generally limited to patients at the extremes of age (65years and those with comorbid medical illness. The most frequent complications of influenza involve the respiratory system.Case Presentation: A 3-year-old boy with a recent history of upper respiratory tract infection developed a nephrotic syndrome. Together with prednisone, furosemide and albumin bolus, a therapy with oseltamivir was started since the nasopharyngeal swab resulted positive for influenza A/H1N1. Clinical conditions andlaboratory findings progressively improved during hospitalization, becoming normal during a 2 month follow up.Conclusion: The possibility of a renal involvement after influenza A/H1N1 infection should be considered.

  17. Avian influenza virus

    Science.gov (United States)

    Avian influenza (AI) is caused by type A influenza virus, a member of the Orthomyxoviridae family. AI viruses are serologically categorized into 16 hemagglutinin (H1-H16) and 9 neuraminidase (N1-N9) subtypes. All subtypes have been identified in birds. Infections by AI viruses have been reported in ...

  18. Towards universal influenza vaccines?

    NARCIS (Netherlands)

    A.D.M.E. Osterhaus (Albert); R.A.M. Fouchier (Ron); G.F. Rimmelzwaan (Guus)

    2011-01-01

    textabstractVaccination is the most cost-effective way to reduce the considerable disease burden of seasonal influenza. Although seasonal influenza vaccines are effective, their performance in the elderly and immunocompromised individuals would benefit from improvement. Major problems related to the

  19. [Anti-influenza virus agent].

    Science.gov (United States)

    Nakamura, Shigeki; Kohno, Shigeru

    2012-04-01

    The necessity of newly anti-influenza agents is increasing rapidly after the prevalence of pandemic influenza A (H1N1) 2009. In addition to the existing anti-influenza drugs, novel neuraminidase inhibitors such as peramivir (a first intravenous anti-influenza agent) and laninamivir (long acting inhaled anti-influenza agent) can be available. Moreover favipiravir, which shows a novel anti-influenza mechanism acting as RNA polymerase inhibitor, has been developing. These drugs are expected to improve the prognosis of severe cases caused by not only seasonal influenza but pandemic influenza A (H1N1) 2009 virus and H5N1 avian influenza, and also treat oseltamivir-resistant influenza effectively.

  20. Influenza in Bristol Bay, 1919

    Directory of Open Access Journals (Sweden)

    Maria Gilson deValpine

    2015-03-01

    Full Text Available The 1918 influenza pandemic has been blamed for as many as 50 million deaths worldwide. Like all major disasters, the full story of the pandemic includes smaller, less noted episodes that have not attracted historical attention. The story of the 1919 wave of the influenza pandemic in Bristol Bay Alaska is one such lost episode. It is an important story because the most accessible accounts—the Congressional Record and the Coast Guard Report—are inconsistent with reports made by employees, health care workers, and volunteers at the site of the disaster. Salmon fishing industry supervisors and medical officers recorded their efforts to save the region’s Native Alaskans in private company reports. The federal Bureau of Education physician retained wireless transmission, reports, and letters of events. The Coast Guard summarized its work in its Annual Report of 1920. The independent Bureau of Fisheries report to the Department of Commerce reveals the Coast Guard report at striking odds with others and reconciles only one account. This article explores the historical oversight, and attempts to tell the story of the 1919 wave of the pandemic which devastated the Native Alaskan population in this very remote place.

  1. A study of the swine flu (H1N1 epidemic among health care providers of a medical college hospital of Delhi

    Directory of Open Access Journals (Sweden)

    Om Prakash Rajoura

    2011-01-01

    Full Text Available Background: Influenza viruses cause annual epidemics and occasional pandemics that have claimed the lives of millions. Understanding the role of specific perceptions in motivating people to engage in precautionary behavior may help health communicators to improve their messages about outbreaks of new infectious disease generally and swine flu specifically. Objectives: To study the knowledge and practices of health care providers regarding swine flu and to study the attitudes and practices of health care providers toward the prevention of the swine flu epidemic. Materials and Methods: The present study was a cross-sectional (descriptive study and was conducted in the month of September, 2009, among doctors and nurses. A maximum of 40% of the total health care providers of GTB Hospital were covered because of feasibility and logistics, and, therefore, the sample size was 334. Results: Around 75% of the health care providers were aware about the symptoms of swine flu. Mostly, all study subjects were aware that it is transmitted through droplet infection. Correct knowledge of the incubation period of swine flu was known to 80% of the doctors and 69% of the nurses. Knowledge about high-risk groups (contacts, travelers, health care providers was observed among 88% of the doctors and 78.8% of the nurses. Practice of wearing mask during duty hours was observed among 82.6% of doctors and 85% of nurses, whereas of the total study population, only 40% were correctly using mask during duty hours. Conclusions: Significant gaps observed between knowledge and actual practice of the Health Care Provider regarding swine flu need to be filled by appropriate training. Data indicate that the health care providers are very intellectual, but they do not themselves practice what they preach.

  2. Barriers to pandemic influenza vaccination and uptake of seasonal influenza vaccine in the post-pandemic season in Germany

    Directory of Open Access Journals (Sweden)

    Böhmer Merle M

    2012-10-01

    Full Text Available Abstract Background In Germany, annual vaccination against seasonal influenza is recommended for certain target groups (e.g. persons aged ≥60 years, chronically ill persons, healthcare workers (HCW. In season 2009/10, vaccination against pandemic influenza A(H1N1pdm09, which was controversially discussed in the public, was recommended for the whole population. The objectives of this study were to assess vaccination coverage for seasonal (seasons 2008/09-2010/11 and pandemic influenza (season 2009/10, to identify predictors of and barriers to pandemic vaccine uptake and whether the controversial discussions on pandemic vaccination has had a negative impact on seasonal influenza vaccine uptake in Germany. Methods We analysed data from the ‘German Health Update’ (GEDA10 telephone survey (n=22,050 and a smaller GEDA10-follow-up survey (n=2,493, which were both representative of the general population aged ≥18 years living in Germany. Results Overall only 8.8% of the adult population in Germany received a vaccination against pandemic influenza. High socioeconomic status, having received a seasonal influenza shot in the previous season, and belonging to a target group for seasonal influenza vaccination were independently associated with the uptake of pandemic vaccines. The main reasons for not receiving a pandemic vaccination were ‘fear of side effects’ and the opinion that ‘vaccination was not necessary’. Seasonal influenza vaccine uptake in the pre-pandemic season 2008/09 was 52.8% among persons aged ≥60 years; 30.5% among HCW, and 43.3% among chronically ill persons. A decrease in vaccination coverage was observed across all target groups in the first post-pandemic season 2010/11 (50.6%, 25.8%, and 41.0% vaccination coverage, respectively. Conclusions Seasonal influenza vaccination coverage in Germany remains in all target groups below 75%, which is a declared goal of the European Union. Our results suggest that controversial

  3. Effectiveness of seasonal influenza vaccination in healthcare workers: a systematic review.

    Science.gov (United States)

    Ng, A N M; Lai, C K Y

    2011-12-01

    Vaccination is considered a key measure to protect vulnerable groups against influenza infection. The objectives of this review are to determine the effect of influenza vaccinations in reducing laboratory-confirmed influenza infections, influenza-like illnesses (ILIs), working days lost among vaccinated HCWs, and associated adverse effects after vaccination. Twenty-two healthcare-related databases and internet resources, as well as reference lists, and the bibliographies of all of the retrieved articles were examined. All randomized controlled trials (RCTs) comparing the effectiveness of any kind of influenza vaccine among all groups of HCWs with a placebo/vaccine other than the influenza vaccine/no intervention were included in the review. Only three RCTs matched the inclusion criteria. There is a limited amount of evidence suggesting that receiving influenza vaccination reduces laboratory-confirmed influenza infections in HCWs. No evidence can be found of influenza vaccinations significantly reducing the incidence of influenza, number of ILI episodes, days with ILI symptoms, or amount of sick leave taken among vaccinated HCWs. There is insufficient data to assess the adverse effects after vaccination. There is no definitive conclusion on the effectiveness of influenza vaccinations in HCWs because of the limited number of related trials. Further research is necessary to evaluate whether annual vaccination is a key measure to protect HCWs against influenza infection and thus increase their confidence in the vaccine. In the mean time, the direction of promoting influenza vaccination to HCWs can be shifted from staff protection to patient protection, with accurate information to address concerns and misconceptions.

  4. Heroin epidemics, treatment and ODE modelling.

    Science.gov (United States)

    White, Emma; Comiskey, Catherine

    2007-07-01

    The UN [United Nations Office on Drugs and Crime (UNODC): World Drug Report, 2005, vol. 1: Analysis. UNODC, 2005.], EU [European Monitoring Centre for Drugs and Drug Addiction (EMCDDA): Annual Report, 2005.http://annualreport.emcdda.eu.int/en/home-en.html.] and WHO [World Health Organisation (WHO): Biregional Strategy for Harm Reduction, 2005-2009. HIV and Injecting Drug Use. WHO, 2005.] have consistently highlighted in recent years the ongoing and persistent nature of opiate and particularly heroin use on a global scale. While this is a global phenomenon, authors have emphasised the significant impact such an epidemic has on individual lives and on society. National prevalence studies have indicated the scale of the problem, but the drug-using career, typically consisting of initiation, habitual use, a treatment-relapse cycle and eventual recovery, is not well understood. This paper presents one of the first ODE models of opiate addiction, based on the principles of mathematical epidemiology. The aim of this model is to identify parameters of interest for further study, with a view to informing and assisting policy-makers in targeting prevention and treatment resources for maximum effectiveness. An epidemic threshold value, R(0), is proposed for the drug-using career. Sensitivity analysis is performed on R(0) and it is then used to examine the stability of the system. A condition under which a backward bifurcation may exist is found, as are conditions that permit the existence of one or more endemic equilibria. A key result arising from this model is that prevention is indeed better than cure.

  5. Stochastic Processes in Epidemic Theory

    CERN Document Server

    Lefèvre, Claude; Picard, Philippe

    1990-01-01

    This collection of papers gives a representative cross-selectional view of recent developments in the field. After a survey paper by C. Lefèvre, 17 other research papers look at stochastic modeling of epidemics, both from a theoretical and a statistical point of view. Some look more specifically at a particular disease such as AIDS, malaria, schistosomiasis and diabetes.

  6. Visual Mining of Epidemic Networks

    CERN Document Server

    Clémençon, Stéphan; Rossi, Fabrice; Tran, Viet Chi; 10.1007/978-3-642-21498-1_35

    2012-01-01

    We show how an interactive graph visualization method based on maximal modularity clustering can be used to explore a large epidemic network. The visual representation is used to display statistical tests results that expose the relations between the propagation of HIV in a sexual contact network and the sexual orientation of the patients.

  7. Epidemic Spread in Human Networks

    CERN Document Server

    Sahneh, Faryad Darabi

    2011-01-01

    One of the popular dynamics on complex networks is the epidemic spreading. An epidemic model describes how infections spread throughout a network. Among the compartmental models used to describe epidemics, the Susceptible-Infected-Susceptible (SIS) model has been widely used. In the SIS model, each node can be susceptible, become infected with a given infection rate, and become again susceptible with a given curing rate. In this paper, we add a new compartment to the classic SIS model to account for human response to epidemic spread. Each individual can be infected, susceptible, or alert. Susceptible individuals can become alert with an alerting rate if infected individuals exist in their neighborhood. An individual in the alert state is less probable to become infected than an individual in the susceptible state; due to a newly adopted cautious behavior. The problem is formulated as a continuous-time Markov process on a general static graph and then modeled into a set of ordinary differential equations using...

  8. Epidemic Synchronization in Robotic Swarms

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Nielsen, Jens Frederik Dalsgaard; Ngo, Trung Dung

    2009-01-01

    Clock synchronization in swarms of networked mobile robots is studied in a probabilistic, epidemic framework. In this setting communication and synchonization is considered to be a randomized process, taking place at unplanned instants of geographical rendezvous between robots. In combination wit...

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

    Science.gov (United States)

    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.

    2015-07-01

    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.

  10. [Epidemiology of influenza A (H1N1) worldwide and in Spain].

    Science.gov (United States)

    Vaqué, Josep

    2010-03-01

    On June 11, 2009, the World Health Organization declared an established pandemic due to a new influenza virus A (H1N1) of swine origin. Initial cases were detected in Mexico in March and within 6 weeks the virus had spread worldwide. The transmissibility of influenza A (H1NA) is slightly higher than that of the seasonal virus, but its pathogenicity and virulence are low. The main target groups of this new virus have been children and young adults under 30 years old. Mortality has affected mainly persons aged between 20 and 50 years old. In areas with temperate climates, two epidemic waves have occurred. The first one, from mid-April to mid-August, affected Mexico, the United States and, consecutively, Spain, England, Japan, and other countries in the northern hemisphere. A few weeks later, coinciding with the beginning of the influenza season, the H1N1 epidemic started in the southern hemisphere countries, especially Argentina, Chile, Australia and New Zealand; in these countries, the epidemic finished at the end of September or October. The second wave affected the northern hemisphere, starting in the United States and Mexico at the beginning of September, and a few weeks later in European countries. In mid-December, this wave was considered to have ended, although some influenza activity persists. The intensity of this second wave was higher compared to the first one.

  11. Effect of modelling slum populations on influenza spread in Delhi

    Science.gov (United States)

    Chen, Jiangzhuo; Chu, Shuyu; Chungbaek, Youngyun; Khan, Maleq; Kuhlman, Christopher; Marathe, Achla; Mortveit, Henning; Vullikanti, Anil; Xie, Dawen

    2016-01-01

    Objectives This research studies the impact of influenza epidemic in the slum and non-slum areas of Delhi, the National Capital Territory of India, by taking proper account of slum demographics and residents’ activities, using a highly resolved social contact network of the 13.8 million residents of Delhi. Methods An SEIR model is used to simulate the spread of influenza on two different synthetic social contact networks of Delhi, one where slums and non-slums are treated the same in terms of their demographics and daily sets of activities and the other, where slum and non-slum regions have different attributes. Results Differences between the epidemic outcomes on the two networks are large. Time-to-peak infection is overestimated by several weeks, and the cumulative infection rate and peak infection rate are underestimated by 10–50%, when slum attributes are ignored. Conclusions Slum populations have a significant effect on influenza transmission in urban areas. Improper specification of slums in large urban regions results in underestimation of infections in the entire population and hence will lead to misguided interventions by policy planners. PMID:27687898

  12. Epidemics spreading in interconnected complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Institute of High Performance Computing, Agency for Science, Technology and Research (A-STAR), Singapore 138632 (Singapore); Xiao, G., E-mail: egxxiao@ntu.edu.sg [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2012-09-03

    We study epidemic spreading in two interconnected complex networks. It is found that in our model the epidemic threshold of the interconnected network is always lower than that in any of the two component networks. Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. Theoretical analysis and simulation results show that, generally speaking, the epidemic size is not significantly affected by the inter-network correlation. In interdependent networks which can be viewed as a special case of interconnected networks, however, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant. -- Highlights: ► We study epidemic spreading in two interconnected complex networks. ► The epidemic threshold is lower than that in any of the two networks. And Interconnection correlation has impacts on threshold and average outbreak size. ► Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. ► We demonstrated and proved that Interconnection correlation does not affect epidemic size significantly. ► In interdependent networks, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant.

  13. Climate-based models for understanding and forecasting dengue epidemics.

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    Elodie Descloux

    Full Text Available BACKGROUND: Dengue dynamics are driven by complex interactions between human-hosts, mosquito-vectors and viruses that are influenced by environmental and climatic factors. The objectives of this study were to analyze and model the relationships between climate, Aedes aegypti vectors and dengue outbreaks in Noumea (New Caledonia, and to provide an early warning system. METHODOLOGY/PRINCIPAL FINDINGS: Epidemiological and meteorological data were analyzed from 1971 to 2010 in Noumea. Entomological surveillance indices were available from March 2000 to December 2009. During epidemic years, the distribution of dengue cases was highly seasonal. The epidemic peak (March-April lagged the warmest temperature by 1-2 months and was in phase with maximum precipitations, relative humidity and entomological indices. Significant inter-annual correlations were observed between the risk of outbreak and summertime temperature, precipitations or relative humidity but not ENSO. Climate-based multivariate non-linear models were developed to estimate the yearly risk of dengue outbreak in Noumea. The best explicative meteorological variables were the number of days with maximal temperature exceeding 32°C during January-February-March and the number of days with maximal relative humidity exceeding 95% during January. The best predictive variables were the maximal temperature in December and maximal relative humidity during October-November-December of the previous year. For a probability of dengue outbreak above 65% in leave-one-out cross validation, the explicative model predicted 94% of the epidemic years and 79% of the non epidemic years, and the predictive model 79% and 65%, respectively. CONCLUSIONS/SIGNIFICANCE: The epidemic dynamics of dengue in Noumea were essentially driven by climate during the last forty years. Specific conditions based on maximal temperature and relative humidity thresholds were determinant in outbreaks occurrence. Their persistence was

  14. Estimating individual and household reproduction numbers in an emerging epidemic.

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    Christophe Fraser

    Full Text Available Reproduction numbers, defined as averages of the number of people infected by a typical case, play a central role in tracking infectious disease outbreaks. The aim of this paper is to develop methods for estimating reproduction numbers which are simple enough that they could be applied with limited data or in real time during an outbreak. I present a new estimator for the individual reproduction number, which describes the state of the epidemic at a point in time rather than tracking individuals over time, and discuss some potential benefits. Then, to capture more of the detail that micro-simulations have shown is important in outbreak dynamics, I analyse a model of transmission within and between households, and develop a method to estimate the household reproduction number, defined as the number of households infected by each infected household. This method is validated by numerical simulations of the spread of influenza and measles using historical data, and estimates are obtained for would-be emerging epidemics of these viruses. I argue that the household reproduction number is useful in assessing the impact of measures that target the household for isolation, quarantine, vaccination or prophylactic treatment, and measures such as social distancing and school or workplace closures which limit between-household transmission, all of which play a key role in current thinking on future infectious disease mitigation.

  15. Prediction of H7N9 epidemic in China

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhaojie; Xia Yao; Lu Yi; Yang Jingchao; Zhang Luwen; Su Hui; Lin Lili

    2014-01-01

    Background In March 2013,human cases of infection with a novel A (H7N9) influenza virus emerged in China.The epidemic spread quickly and as of 6 May 2013,there were 129 confirmed cases.The purpose of this study was to analyze the epidemiology of the confirmed cases,determine the impacts of bird migration and temperature changes on the H7N9 epidemic,predict the future trends of the epidemic,explore the response patterns of the government and propose preventive suggestions.Methods The geographic,temporal and population distribution of all cases reported up to 6 May 2013 were described from available records.Risk assessment standard was established by analysing the temperature and relative humidity records during the period of extensive outbreak in three epidemic regions in eastern China,including Shanghai,Zhejiang and Jiangsu provinces.Risk assessment maps were created by combining the bird migration routes in eastern China with the monthly average temperatures from May 1993 to December 2012 nationwide.Results Among the confirmed cases,there were more men than women,and 50.4% were elderly adults (age >61 years).The major demographic groups were retirees and farmers.The temperature on the days of disease onset was concentrated in the range of 9℃-19℃; we defined 9℃-19℃ as the high-risk temperature range,0℃-9℃ or 19℃-25℃ as medium risk and <0℃ or >25℃ as low risk.The relative humidity on the days of disease onset ranged widely from 25% to 99%,but did not correlate with the incidence of infection.Based on the temperature analysis and the eastern bird migration routes,we predicted that after May,the high-risk region would move to the northeast and inland,while after September,it would move back to north China.Conclusions Temperature and bird migration strongly influence the spread of the H7N9 virus.In order to control the H7N9 epidemic effectively,Chinese authorities should strengthen the surveillance of migrating birds,increase poultry and

  16. Influenza in outpatient ILI case-patients in national hospital-based surveillance, Bangladesh, 2007-2008.

    Directory of Open Access Journals (Sweden)

    Rashid Uz Zaman

    Full Text Available BACKGROUND: Recent population-based estimates in a Dhaka low-income community suggest that influenza was prevalent among children. To explore the epidemiology and seasonality of influenza throughout the country and among all age groups, we established nationally representative hospital-based surveillance necessary to guide influenza prevention and control efforts. METHODOLOGY/PRINCIPAL FINDINGS: We conducted influenza-like illness and severe acute respiratory illness sentinel surveillance in 12 hospitals across Bangladesh during May 2007-December 2008. We collected specimens from 3,699 patients, 385 (10% which were influenza positive by real time RT-PCR. Among the sample-positive patients, 192 (51% were type A and 188 (49% were type B. Hemagglutinin subtyping of type A viruses detected 137 (71% A/H1 and 55 (29% A/H3, but no A/H5 or other novel influenza strains. The frequency of influenza cases was highest among children aged under 5 years (44%, while the proportions of laboratory confirmed cases was highest among participants aged 11-15 (18%. We applied kriging, a geo-statistical technique, to explore the spatial and temporal spread of influenza and found that, during 2008, influenza was first identified in large port cities and then gradually spread to other parts of the country. We identified a distinct influenza peak during the rainy season (May-September. CONCLUSIONS/SIGNIFICANCE: Our surveillance data confirms that influenza is prevalent throughout Bangladesh, affecting a wide range of ages and causing considerable morbidity and hospital care. A unimodal influenza seasonality may allow Bangladesh to time annual influenza prevention messages and vaccination campaigns to reduce the national influenza burden. To scale-up such national interventions, we need to quantify the national rates of influenza and the economic burden associated with this disease through further studies.

  17. Acute infectious diseases and immunologic responses. Some stories from clinical practice apropos the Influenza A (H1N1 pandemic

    Directory of Open Access Journals (Sweden)

    Alfredo Darío Espinosa Brito

    2011-04-01

    Full Text Available Apropos of the appearance of some unusual clinical pictures in the course of the recent epidemic of Influenza A (H1N1, and with the intention of sharing controversial ideas related to the immunologic responses of the patients to the infectious agents, we expose here a group of stories arisen from a clinical practice of almost five decades.

  18. Statistical estimates of absenteeism attributable to seasonal and pandemic influenza from the Canadian Labour Force Survey

    Directory of Open Access Journals (Sweden)

    Zheng Hui

    2011-04-01

    Full Text Available Abstract Background As many respiratory viruses are responsible for influenza like symptoms, accurate measures of the disease burden are not available and estimates are generally based on statistical methods. The objective of this study was to estimate absenteeism rates and hours lost due to seasonal influenza and compare these estimates with estimates of absenteeism attributable to the two H1N1 pandemic waves that occurred in 2009. Methods Key absenteeism variables were extracted from Statistics Canada's monthly labour force survey (LFS. Absenteeism and the proportion of hours lost due to own illness or disability were modelled as a function of trend, seasonality and proxy variables for influenza activity from 1998 to 2009. Results Hours lost due to the H1N1/09 pandemic strain were elevated compared to seasonal influenza, accounting for a loss of 0.2% of potential hours worked annually. In comparison, an estimated 0.08% of hours worked annually were lost due to seasonal influenza illnesses. Absenteeism rates due to influenza were estimated at 12% per year for seasonal influenza over the 1997/98 to 2008/09 seasons, and 13% for the two H1N1/09 pandemic waves. Employees who took time off due to a seasonal influenza infection took an average of 14 hours off. For the pandemic strain, the average absence was 25 hours. Conclusions This study confirms that absenteeism due to seasonal influenza has typically ranged from 5% to 20%, with higher rates associated with multiple circulating strains. Absenteeism rates for the 2009 pandemic were similar to those occurring for seasonal influenza. Employees took more time off due to the pandemic strain than was typical for seasonal influenza.

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

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    Ristić Mioljub

    2010-01-01

    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.

  20. Partial protection of seasonal trivalent inactivated vaccine against novel pandemic influenza A/H1N1 2009: case-control study in Mexico City

    Science.gov (United States)

    Garcia-Garcia, Lourdes; Valdespino-Gómez, Jose Luis; Lazcano-Ponce, Eduardo; Jimenez-Corona, Aida; Higuera-Iglesias, Anjarath; Cruz-Hervert, Pablo; Cano-Arellano, Bulmaro; Garcia-Anaya, Antonio; Ferreira-Guerrero, Elizabeth; Baez-Saldaña, Renata; Ferreyra-Reyes, Leticia; Ponce-de-León-Rosales, Samuel; Alpuche-Aranda, Celia; Rodriguez-López, Mario Henry; Perez-Padilla, Rogelio; Hernandez-Avila, Mauricio

    2009-01-01

    Objective To evaluate the association of 2008-9 seasonal trivalent inactivated vaccine with cases of influenza A/H1N1 during the epidemic in Mexico. Design Frequency matched case-control study. Setting Specialty hospital in Mexico City, March to May 2009. Participants 60 patients with laboratory confirmed influenza A/H1N1 and 180 controls with other diseases (not influenza-like illness or pneumonia) living in Mexico City or the State of Mexico and matched for age and socioeconomic status. Main outcome measures Odds ratio and effectiveness of trivalent inactivated vaccine against influenza A/H1N1. Results Cases were more likely than controls to be admitted to hospital, undergo invasive mechanical ventilation, and die. Controls were more likely than cases to have chronic conditions that conferred a higher risk of influenza related complications. In the multivariate model, influenza A/H1N1 was independently associated with trivalent inactivated vaccine (odds ratio 0.27, 95% confidence interval 0.11 to 0.66) and underlying conditions (0.15, 0.08 to 0.30). Vaccine effectiveness was 73% (95% confidence interval 34% to 89%). None of the eight vaccinated cases died. Conclusions Preliminary evidence suggests some protection from the 2008-9 trivalent inactivated vaccine against pandemic influenza A/H1N1 2009, particularly severe forms of the disease, diagnosed in a specialty hospital during the influenza epidemic in Mexico City. PMID:19808768

  1. Anti-influenza Virus Effects of Catechins: A Molecular and Clinical Review.

    Science.gov (United States)

    Ide, Kazuke; Kawasaki, Yohei; Kawakami, Koji; Yamada, Hiroshi

    2016-01-01

    Influenza infection and associated epidemics represent a serious public health problem. Several preventive and curative measures exist against its spread including vaccination and therapeutic agents such as neuraminidase inhibitors (e.g., oseltamivir, zanamivir, as well as peramivir and laninamivir, which are licensed in several countries) and adamantanes (e.g., amantadine and rimantadine). However, neuraminidase inhibitor- and adamantane- resistant viruses have been detected, whereas vaccines exhibit strain-specific effects and are limited in supply. Thus, new approaches are needed to prevent and treat influenza infections. Catechins, a class of polyphenolic flavonoids present in tea leaves, have been reported as potential anti-influenza virus agents based on experimental and clinical studies. (-)-epigallocatechin gallate (EGCG), a major and highly bioactive catechin, is known to inhibit influenza A and B virus infections in Madin-Darby canine kidney cells. Additionally, EGCG and other catechin compounds such as epicatechin gallate and catechin-5-gallate also show neuraminidase inhibitory activities as demonstrated via molecular docking. These catechins can bind differently to neuraminidase and might overcome known drug resistancerelated virus mutations. Furthermore, the antiviral effects of chemically modified catechin derivatives have also been investigated, and future structure-based drug design studies of catechin derivatives might contribute to improvements in influenza prevention and treatment. This review briefly summarizes probable mechanisms underlying the inhibitory effects of tea catechins against influenza infection and their clinical benefits on influenza prevention and treatment. Additionally, the great potential of tea catechins and their chemical derivatives as effective antiviral agents is described.

  2. Rainfall mediations in the spreading of epidemic cholera

    Science.gov (United States)

    Righetto, L.; Bertuzzo, E.; Mari, L.; Schild, E.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2013-10-01

    Following the empirical evidence of a clear correlation between rainfall events and cholera resurgence that was observed in particular during the recent outbreak in Haiti, a spatially explicit model of epidemic cholera is re-examined. Specifically, we test a multivariate Poisson rainfall generator, with parameters varying in space and time, as a driver of enhanced disease transmission. The relevance of the issue relates to the key insight that predictive mathematical models may provide into the course of an ongoing cholera epidemic aiding emergency management (say, in allocating life-saving supplies or health care staff) or in evaluating alternative management strategies. Our model consists of a set of dynamical equations (SIRB-like i.e. subdivided into the compartments of Susceptible, Infected and Recovered individuals, and including a balance of Bacterial concentrations in the water reservoir) describing a connected network of human communities where the infection results from the exposure to excess concentrations of pathogens in the water. These, in turn, are driven by rainfall washout of open-air defecation sites or cesspool overflows, hydrologic transport through waterways and by mobility of susceptible and infected individuals. We perform an a posteriori analysis (from the beginning of the epidemic in October 2010 until December 2011) to test the model reliability in predicting cholera cases and in testing control measures, involving vaccination and sanitation campaigns, for the ongoing epidemic. Even though predicting reliably the timing of the epidemic resurgence proves difficult due to rainfall inter-annual variability, we find that the model can reasonably quantify the total number of reported infection cases in the selected time-span. We then run a multi-seasonal prediction of the course of the epidemic until December 2015, to investigate conditions for further resurgences and endemicity of cholera in the region with a view to policies which may bring to

  3. New treatments for influenza.

    Science.gov (United States)

    Barik, Sailen

    2012-09-13

    Influenza has a long history of causing morbidity and mortality in the human population through routine seasonal spread and global pandemics. The high mutation rate of the RNA genome of the influenza virus, combined with assortment of its multiple genomic segments, promote antigenic diversity and new subtypes, allowing the virus to evade vaccines and become resistant to antiviral drugs. There is thus a continuing need for new anti-influenza therapy using novel targets and creative strategies. In this review, we summarize prospective future therapeutic regimens based on recent molecular and genomic discoveries.

  4. New treatments for influenza

    Directory of Open Access Journals (Sweden)

    Barik Sailen

    2012-09-01

    Full Text Available Abstract Influenza has a long history of causing morbidity and mortality in the human population through routine seasonal spread and global pandemics. The high mutation rate of the RNA genome of the influenza virus, combined with assortment of its multiple genomic segments, promote antigenic diversity and new subtypes, allowing the virus to evade vaccines and become resistant to antiviral drugs. There is thus a continuing need for new anti-influenza therapy using novel targets and creative strategies. In this review, we summarize prospective future therapeutic regimens based on recent molecular and genomic discoveries.

  5. Multiple routes transmitted epidemics on multiplex networks

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dawei [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Shandong Provincial Key Laboratory of Computer Network, Shandong Computer Science Center, Jinan 250014 (China); Li, Lixiang [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Peng, Haipeng, E-mail: penghaipeng@bupt.edu.cn [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Luo, Qun; Yang, Yixian [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China)

    2014-02-01

    This letter investigates the multiple routes transmitted epidemic process on multiplex networks. We propose detailed theoretical analysis that allows us to accurately calculate the epidemic threshold and outbreak size. It is found that the epidemic can spread across the multiplex network even if all the network layers are well below their respective epidemic thresholds. Strong positive degree–degree correlation of nodes in multiplex network could lead to a much lower epidemic threshold and a relatively smaller outbreak size. However, the average similarity of neighbors from different layers of nodes has no obvious effect on the epidemic threshold and outbreak size. -- Highlights: •We studies multiple routes transmitted epidemic process on multiplex networks. •SIR model and bond percolation theory are used to analyze the epidemic processes. •We derive equations to accurately calculate the epidemic threshold and outbreak size. •ASN has no effect on the epidemic threshold and outbreak size. •Strong positive DDC leads to a lower epidemic threshold and a smaller outbreak size.

  6. Challenges and Strategies of Laboratory Diagnosis for Newly Emerging Influenza Viruses in Taiwan: A Decade after SARS

    Directory of Open Access Journals (Sweden)

    Jih-Hui Lin

    2015-01-01

    Full Text Available Since the first case of severe acute respiratory syndrome (SARS in Taiwan was identified in March 2003, viral respiratory infections, in particular the influenza virus, have become a national public health concern. Taiwan would face a serious threat of public health problems if another SARS epidemic overlapped with a flu outbreak. After SARS, the Taiwan Centers for Disease Control accelerated and strengthened domestic research on influenza and expanded the exchange of information with international counterparts. The capacity of influenza A to cross species barriers presents a potential threat to human health. Given the mutations of avian flu viruses such as H7N9, H6N1, and H10N8, all countries, including Taiwan, must equip themselves to face a possible epidemic or pandemic. Such preparedness requires global collaboration.

  7. Gradual changes in the age distribution of excess deaths in the years following the 1918 influenza pandemic in Copenhagen

    DEFF Research Database (Denmark)

    Saglanmak, Neslihan; Andreasen, Viggo; Simonsen, Lone

    2011-01-01

    Background: The 1918 influenza pandemic was associated with an unusual age pattern of mortality, with most deaths occurring among young adults. Few studies have addressed changes in the age distribution for influenza-related mortality in the pre-pandemic and post-pandemic period, which has...... on trends in the rate ratio of excess respiratory mortality in people under and over 65 years. Conclusions: The unusual elevation of excess respiratory mortality rates in young and middle-aged adults was confined to the first three years of A/H1N1 virus circulation 1918–1920; the rapid return to “epidemic...... in the recrudescent pandemic wave of 1919–1920 may suggest the emergence of an early influenza A/H1N1 drift variant. Subsequent drift events may have been associated with the particularly severe 1928–1929 epidemic in Denmark and elsewhere....

  8. Introduction of a Novel Swine-Origin Influenza A (H1N1 Virus into Milwaukee, Wisconsin in 2009

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    Swati Kumar

    2009-06-01

    Full Text Available On 17 April 2009, novel swine origin influenza A virus (S-OIV cases appeared within the United States. Most influenza A diagnostic assays currently utilized in local clinical laboratories do not allow definitive subtype determination. Detailed subtype analysis of influenza A positive samples in our laboratory allowed early confirmation of a large outbreak of S-OIV in southeastern Wisconsin (SEW. The initial case of S-OIV in SEW was detected on 28 April 2009. All influenza A samples obtained during the 16 week period prior to 28 April 2009, and the first four weeks of the subsequent epidemic were sub typed. Four different multiplex assays were employed, utilizing real time PCR and end point PCR to fully subtype human and animal influenza viral components. Specific detection of S-OIV was developed within days. Data regarding patient demographics and other concurrently circulating viruses were analyzed. During the first four weeks of the epidemic, 679 of 3726 (18.2% adults and children tested for influenza A were identified with S-OIV infection. Thirteen patients (0.34% tested positive for seasonal human subtypes of influenza A during the first two weeks and none in the subsequent 2 weeks of the epidemic. Parainfluenza viruses were the most prevalent seasonal viral agents circulating during the epidemic (of those tested, with detection rates of 12% followed by influenza B and RSV at 1.9% and 0.9% respectively. S-OIV was confirmed on day 2 of instituting subtype testing and within 4 days of report of national cases of S-OIV. Novel surge capacity diagnostic infrastructure exists in many specialty and research laboratories around the world. The capacity for broader influenza A sub typing at the local laboratory level allows timely and accurate detection of novel strains as they emerge in the community, despite the presence of other circulating viruses producing identical illness. This is likely to become increasingly important given the need for

  9. Chaos Versus Noisy Periodicity: Alternative Hypotheses for Childhood Epidemics

    Science.gov (United States)

    Olsen, L. F.; Schaffer, W. M.

    1990-08-01

    Whereas case rates for some childhood diseases (chickenpox) often vary according to an almost regular annual cycle, the incidence of more efficiently transmitted infections such as measles is more variable. Three hypotheses have been proposed to account for such fluctuations. (i) Irregular dynamics result from random shocks to systems with stable equilibria. (ii) The intrinsic dynamics correspond to biennial cycles that are subject to stochastic forcing. (iii) Aperiodic fluctuations are intrinsic to the epidemiology. Comparison of real world data and epidemiological models suggests that measles epidemics are inherently chaotic. Conversely, the extent to which chickenpox outbreaks approximate a yearly cycle depends inversely on the population size.

  10. Monitoring Epidemic of Tobacco Use, Promote Tobacco Control

    Institute of Scientific and Technical Information of China (English)

    Gong-Huan YANG

    2010-01-01

    @@ Tobacco use is a major cause of preventable disease and premature death. The tobacco epidemic is responsible for 5.4 million deaths annually and killed 100 million people worldwide in the last century. It is estimated that by 2030 there will be more than 8 million deaths every year attributable to tobacco use and that more than 80% of these will occur in developing countries. By the end of the 21st century,1 billion people will have died from cigarette smoke[1].

  11. Antiviral effect of methylated flavonol isorhamnetin against influenza.

    Science.gov (United States)

    Abdal Dayem, Ahmed; Choi, Hye Yeon; Kim, Young Bong; Cho, Ssang-Goo

    2015-01-01

    Influenza is an infectious respiratory disease with frequent seasonal epidemics that causes a high rate of mortality and morbidity in humans, poultry, and animals. Influenza is a serious economic concern due to the costly countermeasures it necessitates. In this study, we compared the antiviral activities of several flavonols and other flavonoids with similar, but distinct, hydroxyl or methyl substitution patterns at the 3, 3', and 4' positions of the 15-carbon flavonoid skeleton, and found that the strongest antiviral effect was induced by isorhamnetin. Similar to quercetin and kaempferol, isorhamnetin possesses a hydroxyl group on the C ring, but it has a 3'-methyl group on the B ring that is absent in quercetin and kaempferol. Co-treatment and pre-treatment with isorhamnetin produced a strong antiviral effect against the influenza virus A/PR/08/34(H1N1). However, isorhamnetin showed the most potent antiviral potency when administered after viral exposure (post-treatment method) in vitro. Isorhamnetin treatment reduced virus-induced ROS generation and blocked cytoplasmic lysosome acidification and the lipidation of microtubule associated protein1 light chain 3-B (LC3B). Oral administration of isorhamnetin in mice infected with the influenza A virus significantly decreased lung virus titer by 2 folds, increased the survival rate which ranged from 70-80%, and decreased body weight loss by 25%. In addition, isorhamnetin decreased the virus titer in ovo using embryonated chicken eggs. The structure-activity relationship (SAR) of isorhamnetin could explain its strong anti-influenza virus potency; the methyl group located on the B ring of isorhamnetin may contribute to its strong antiviral potency against influenza virus in comparison with other flavonoids.

  12. Antiviral effect of methylated flavonol isorhamnetin against influenza.

    Directory of Open Access Journals (Sweden)

    Ahmed Abdal Dayem

    Full Text Available Influenza is an infectious respiratory disease with frequent seasonal epidemics that causes a high rate of mortality and morbidity in humans, poultry, and animals. Influenza is a serious economic concern due to the costly countermeasures it necessitates. In this study, we compared the antiviral activities of several flavonols and other flavonoids with similar, but distinct, hydroxyl or methyl substitution patterns at the 3, 3', and 4' positions of the 15-carbon flavonoid skeleton, and found that the strongest antiviral effect was induced by isorhamnetin. Similar to quercetin and kaempferol, isorhamnetin possesses a hydroxyl group on the C ring, but it has a 3'-methyl group on the B ring that is absent in quercetin and kaempferol. Co-treatment and pre-treatment with isorhamnetin produced a strong antiviral effect against the influenza virus A/PR/08/34(H1N1. However, isorhamnetin showed the most potent antiviral potency when administered after viral exposure (post-treatment method in vitro. Isorhamnetin treatment reduced virus-induced ROS generation and blocked cytoplasmic lysosome acidification and the lipidation of microtubule associated protein1 light chain 3-B (LC3B. Oral administration of isorhamnetin in mice infected with the influenza A virus significantly decreased lung virus titer by 2 folds, increased the survival rate which ranged from 70-80%, and decreased body weight loss by 25%. In addition, isorhamnetin decreased the virus titer in ovo using embryonated chicken eggs. The structure-activity relationship (SAR of isorhamnetin could explain its strong anti-influenza virus potency; the methyl group located on the B ring of isorhamnetin may contribute to its strong antiviral potency against influenza virus in comparison with other flavonoids.

  13. The feasibility of age-specific travel restrictions during influenza pandemics

    Directory of Open Access Journals (Sweden)

    Lam Elson HY

    2011-11-01

    Full Text Available Abstract Background Epidemiological studies have shown that imposing travel restrictions to prevent or delay an influenza pandemic may not be feasible. To delay an epidemic substantially, an extremely high proportion of trips (~99% would have to be restricted in a homogeneously mixing population. Influenza is, however, strongly influenced by age-dependent transmission dynamics, and the effectiveness of age-specific travel restrictions, such as the selective restriction of travel by children, has yet to be examined. Methods A simple stochastic model was developed to describe the importation of infectious cases into a population and to model local chains of transmission seeded by imported cases. The probability of a local epidemic, and the time period until a major epidemic takes off, were used as outcome measures, and travel restriction policies in which children or adults were preferentially restricted were compared to age-blind restriction policies using an age-dependent next generation matrix parameterized for influenza H1N1-2009. Results Restricting children from travelling would yield greater reductions to the short-term risk of the epidemic being established locally than other policy options considered, and potentially could delay an epidemic for a few weeks. However, given a scenario with a total of 500 imported cases over a period of a few months, a substantial reduction in the probability of an epidemic in this time period is possible only if the transmission potential were low and assortativity (i.e. the proportion of contacts within-group were unrealistically high. In all other scenarios considered, age-structured travel restrictions would not prevent an epidemic and would not delay the epidemic for longer than a few weeks. Conclusions Selectively restricting children from traveling overseas during a pandemic may potentially delay its arrival for a few weeks, depending on the characteristics of the pandemic strain, but could have less

  14. Seasonal Influenza Vaccine Uptake in a Respiratory Outpatients Clinic

    LENUS (Irish Health Repository)

    Rossiter, A

    2017-02-01

    Influenza is an acute viral respiratory illness that continues to cause significant morbidity and mortality in Ireland. Despite well-established national and international guidelines1 and increased public awareness campaigns, vaccine uptake rates are well below target worldwide2. We performed an audit of influenza vaccine uptake at a Respiratory outpatient clinic in a tertiary referral centre. 54% (n=41) of patients received the annual vaccine, well below the target of 75% set by the European Centre for Disease Prevention and Control (ECDC).

  15. Memory T cells generated by prior exposure to influenza cross react with the novel H7N9 influenza virus and confer protective heterosubtypic immunity.

    Directory of Open Access Journals (Sweden)

    Sean R McMaster

    Full Text Available Influenza virus is a source of significant health and economic burden from yearly epidemics and sporadic pandemics. Given the potential for the emerging H7N9 influenza virus to cause severe respiratory infections and the lack of exposure to H7 and N9 influenza viruses in the human population, we aimed to quantify the H7N9 cross-reactive memory T cell reservoir in humans and mice previously exposed to common circulating influenza viruses. We identified significant cross-reactive T cell populations in humans and mice; we also found that cross-reactive memory T cells afforded heterosubtypic protection by reducing morbidity and mortality upon lethal H7N9 challenge. In context with our observation that PR8-primed mice have limited humoral cross-reactivity with H7N9, our data suggest protection from H7N9 challenge is indeed mediated by cross-reactive T cell populations established upon previous priming with another influenza virus. Thus, pre-existing cross-reactive memory T cells may limit disease severity in the event of an H7N9 influenza virus pandemic.

  16. Hepatocellular carcinoma and industrial epidemics

    Institute of Scientific and Technical Information of China (English)

    Alain Braillon; Gérard Dubois

    2011-01-01

    Worldwide, the burden of the non viral causes of hepatocellular carcinoma (HCC) is usually underestimated. Clearly industrial goods, tobacco, alcohol and processed foods are the agents of new epidemics in modern times which far outscore the burden of infectious agents on morbidity and mortality. Smoking, a dose-related contributing factor for HCC, receives too little attention in clinical practice. In France, tobacco, hepatitis B and C virus and alcohol are the main risk factors for HCC mortality (33%, 31% and 26%, respectively). In developing countries, where tobacco consumption is dramatically increasing, this epidemic may soon surpass hepatitis B. Obesity and diabetes are the contributing factors too. The role of industrial processed foods in the increase of the prevalence of obesity and diabetes cannot be ignored.

  17. The Economics of Epidemic Diseases.

    Science.gov (United States)

    Dimitri, Nicola

    2015-01-01

    Epidemic, infectious, diseases affect a large number of individuals across developing as well as developed countries. With reference to some very simple diffusion models, in this paper we consider how available economic resources could be optimally allocated by health authorities to mitigate, possibly eradicate, the disease. Optimality was defined as the minimization of the long run number of infected people. The main goal of the work has been to introduce a methodology for deciding if it would be best to concentrate resources to prevent contact between individuals and with an external source, or to develop a new treatment for curing the disease, or both. The analysis suggests that this depends on the cost functions, that is the available technology, for controlling the relevant parameters underlying the epidemics as well as on the available financial resources. In the case of the recent Ebola outbreak, the suggestions of the model have been consistent with the policies adopted.

  18. Associations between Meteorological Parameters and Influenza Activity in Berlin (Germany, Ljubljana (Slovenia, Castile and Leon (Spain and Israeli Districts.

    Directory of Open Access Journals (Sweden)

    Radina P Soebiyanto

    Full Text Available Studies in the literature have indicated that the timing of seasonal influenza epidemic varies across latitude, suggesting the involvement of meteorological and environmental conditions in the transmission of influenza. In this study, we investigated the link between meteorological parameters and influenza activity in 9 sub-national areas with temperate and subtropical climates: Berlin (Germany, Ljubljana (Slovenia, Castile and León (Spain and all 6 districts in Israel.We estimated weekly influenza-associated influenza-like-illness (ILI or Acute Respiratory Infection (ARI incidence to represent influenza activity using data from each country's sentinel surveillance during 2000-2011 (Spain and 2006-2011 (all others. Meteorological data was obtained from ground stations, satellite and assimilated data. Two generalized additive models (GAM were developed, with one using specific humidity as a covariate and another using minimum temperature. Precipitation and solar radiation were included as additional covariates in both models. The models were adjusted for previous weeks' influenza activity, and were trained separately for each study location.Influenza activity was inversely associated (p<0.05 with specific humidity in all locations. Minimum temperature was inversely associated with influenza in all 3 temperate locations, but not in all subtropical locations. Inverse associations between influenza and solar radiation were found in most locations. Associations with precipitation were location-dependent and inconclusive. We used the models to estimate influenza activity a week ahead for the 2010/2011 period which was not used in training the models. With exception of Ljubljana and Israel's Haifa District, the models could closely follow the observed data especially during the start and the end of epidemic period. In these locations, correlation coefficients between the observed and estimated ranged between 0.55 to 0.91and the model

  19. Early estimates of seasonal influenza vaccine effectiveness - United States, January 2015.

    Science.gov (United States)

    Flannery, Brendan; Clippard, Jessie; Zimmerman, Richard K; Nowalk, Mary Patricia; Jackson, Michael L; Jackson, Lisa A; Monto, Arnold S; Petrie, Joshua G; McLean, Huong Q; Belongia, Edward A; Gaglani, Manjusha; Berman, LaShondra; Foust, Angie; Sessions, Wendy; Thaker, Swathi N; Spencer, Sarah; Fry, Alicia M

    2015-01-16

    In the United States, annual vaccination against seasonal influenza is recommended for all persons aged ≥6 months. Each season since 2004-05, CDC has estimated the effectiveness of seasonal influenza vaccine in preventing medically attended acute respiratory illness (ARI) associated with laboratory-confirmed influenza. This season, early estimates of influenza vaccine effectiveness are possible because of widespread, early circulation of influenza viruses. By January 3, 2015, 46 states were experiencing widespread flu activity, with predominance of influenza A (H3N2) viruses. This report presents an initial estimate of seasonal influenza vaccine effectiveness at preventing laboratory-confirmed influenza virus infection associated with medically attended ARI based on data from 2,321 children and adults enrolled in the U.S. Influenza Vaccine Effectiveness Network (Flu VE) during November 10, 2014-January 2, 2015. During this period, overall vaccine effectiveness (VE) (adjusted for study site, age, sex, race/ethnicity, self-rated health, and days from illness onset to enrollment) against laboratory-confirmed influenza associated with medically attended ARI was 23% (95% confidence interval [CI] = 8%-36%). Most influenza infections were due to A (H3N2) viruses. This interim VE estimate is relatively low compared with previous seasons when circulating viruses and vaccine viruses were well-matched and likely reflects the fact that more than two-thirds of circulating A (H3N2) viruses are antigenically and genetically different (drifted) from the A (H3N2) vaccine component of 2014-15 Northern Hemisphere seasonal influenza vaccines. These early, low VE estimates underscore the need for ongoing influenza prevention and treatment measures. CDC continues to recommend influenza vaccination because the vaccine can still prevent some infections with the currently circulating A (H3N2) viruses as well as other viruses that might circulate later in the season, including influenza B

  20. The ESPID/ESWI Joint Symposium - A strong vote for universal influenza vaccination in children in Europe.

    Science.gov (United States)

    Kobbe, Robin

    2015-12-08

    During this year's 33rd annual meeting in Leipzig, Germany, the European Society of Paediatric Infectious Diseases (ESPID) jointly together with the European Scientific Working group on Influenza (ESWI), organized a staged debate on the motion of universal annual immunization of children against influenza as a cost-effective health intervention in Europe. Six invited speakers, all experts in the field of influenza vaccination, who were not necessary confident with their given position of pro or contra, battled each other with short oral presentations to convince the audience to vote for or against the motion.

  1. Networked SIS Epidemics with Awareness

    CERN Document Server

    Paarporn, Keith; Weitz, Joshua S; Shamma, Jeff S

    2016-01-01

    We study an SIS epidemic process over a static contact network where the nodes have partial information about the epidemic state. They react by limiting their interactions with their neighbors when they believe the epidemic is currently prevalent. A node's awareness is weighted by the fraction of infected neighbors in their social network, and a global broadcast of the fraction of infected nodes in the entire network. The dynamics of the benchmark (no awareness) and awareness models are described by discrete-time Markov chains, from which mean-field approximations (MFA) are derived. The states of the MFA are interpreted as the nodes' probabilities of being infected. We show a sufficient condition for existence of a "metastable", or endemic, state of the awareness model coincides with that of the benchmark model. Furthermore, we use a coupling technique to give a full stochastic comparison analysis between the two chains, which serves as a probabilistic analogue to the MFA analysis. In particular, we show that...

  2. Clinical severity of human infections with avian influenza A(H7N9) virus, China, 2013/14.

    Science.gov (United States)

    Feng, L; Wu, J T; Liu, X; Yang, P; Tsang, T K; Jiang, H; Wu, P; Yang, J; Fang, V J; Qin, Y; Lau, E H; Li, M; Zheng, J; Peng, Z; Xie, Y; Wang, Q; Li, Z; Leung, G M; Gao, G F; Yu, H; Cowling, B J

    2014-12-11

    Assessing the severity of emerging infections is challenging because of potential biases in case ascertainment. The first human case of infection with influenza A(H7N9) virus was identified in China in March 2013; since then, the virus has caused two epidemic waves in the country. There were 134 laboratory-confirmed cases detected in the first epidemic wave from January to September 2013. In the second epidemic wave of human infections with avian influenza A(H7N9) virus in China from October 2013 to October 2014, we estimated that the risk of death among hospitalised cases of infection with influenza A(H7N9) virus was 48% (95% credibility interval: 42-54%), slightly higher than the corresponding risk in the first wave. Age-specific risks of death among hospitalised cases were also significantly higher in the second wave. Using data on symptomatic cases identified through national sentinel influenza-like illness surveillance, we estimated that the risk of death among symptomatic cases of infection with influenza A(H7N9) virus was 0.10% (95% credibility interval: 0.029-3.6%), which was similar to previous estimates for the first epidemic wave of human infections with influenza A(H7N9) virus in 2013. An increase in the risk of death among hospitalised cases in the second wave could be real because of changes in the virus, because of seasonal changes in host susceptibility to severe infection, or because of variation in treatment practices between hospitals, while the increase could be artefactual because of changes in ascertainment of cases in different areas at different times.

  3. Bayesian nonparametric clustering in phylogenetics: modeling antigenic evolution in influenza.

    Science.gov (United States)

    Cybis, Gabriela B; Sinsheimer, Janet S; Bedford, Trevor; Rambaut, Andrew; Lemey, Philippe; Suchard, Marc A

    2017-01-18

    Influenza is responsible for up to 500,000 deaths every year, and antigenic variability represents much of its epidemiological burden. To visualize antigenic differences across many viral strains, antigenic cartography methods use multidimensional scaling on binding assay data to map influenza antigenicity onto a low-dimensional space. Analysis of such assay data ideally leads to natural clustering of influenza strains of similar antigenicity that correlate with sequence evolution. To understand the dynamics of these antigenic groups, we present a framework that jointly models genetic and antigenic evolution by combining multidimensional scaling of binding assay data, Bayesian phylogenetic machinery and nonparametric clustering methods. We propose a phylogenetic Chinese restaurant process that extends the current process to incorporate the phylogenetic dependency structure between strains in the modeling of antigenic clusters. With this method, we are able to use the genetic information to better understand the evolution of antigenicity throughout epidemics, as shown in applications of this model to H1N1 influenza. Copyright © 2017 John Wiley & Sons, Ltd.

  4. Vaccination against seasonal influenza

    CERN Multimedia

    DG Unit

    2009-01-01

    As every year, the Medical Service is taking part in the campaign to promote vaccination against seasonal influenza. Vaccination against seasonal influenza is especially recommended for people suffering from chronic lung, cardio-vascular or kidney conditions or diabetes, for those recovering from a serious illness or surgical operation and for everyone over the age of 65. The influenza virus is transmitted by air and contact with contaminated surfaces, hence the importance of washing hands regularly with soap and / or disinfection using a hydro-alcoholic solution. From the onset of symptoms (fever> 38°, chills, cough, muscle aches and / or joint pain, fatigue) you are strongly recommended to stay at home to avoid spreading the virus. In the present context of the influenza A (H1N1) pandemic, it is important to dissociate these two illnesses and emphasise that the two viruses and the vaccines used to combat them are quite different and that protection against one will not pr...

  5. First Aid: Influenza (Flu)

    Science.gov (United States)

    ... after acetaminophen or ibuprofen Think Prevention! Get the flu vaccine each year. Try to avoid large crowds during ... Vaccines My Kids Need? How Many Doses of Flu Vaccine Does My Child Need? Your Child's Immunizations: Influenza ...

  6. BIRD FLU (AVIAN INFLUENZA)

    OpenAIRE

    Ali ACAR; Bulent BESIRBELLIOÐLU

    2005-01-01

    Avian influenza (bird flu) is a contagious disease of animals caused by influenza A viruses. These flu viruses occur naturally among birds. Actually, humans are not infected by bird flu viruses.. However, during an outbreak of bird flu among poultry, there is a possible risk to people who have contact infect birds or surface that have been contaminated with excreations from infected birds. Symptoms of bird flu in humans have ranged from typical flu-like symptoms to eye infections, pneumonia, ...

  7. A lattice model for influenza spreading.

    Directory of Open Access Journals (Sweden)

    Antonella Liccardo

    Full Text Available We construct a stochastic SIR model for influenza spreading on a D-dimensional lattice, which represents the dynamic contact network of individuals. An age distributed population is placed on the lattice and moves on it. The displacement from a site to a nearest neighbor empty site, allows individuals to change the number and identities of their contacts. The dynamics on the lattice is governed by an attractive interaction between individuals belonging to the same age-class. The parameters, which regulate the pattern dynamics, are fixed fitting the data on the age-dependent daily contact numbers, furnished by the Polymod survey. A simple SIR transmission model with a nearest neighbors interaction and some very basic adaptive mobility restrictions complete the model. The model is validated against the age-distributed Italian epidemiological data for the influenza A(H1N1 during the [Formula: see text] season, with sensible predictions for the epidemiological parameters. For an appropriate topology of the lattice, we find that, whenever the accordance between the contact patterns of the model and the Polymod data is satisfactory, there is a good agreement between the numerical and the experimental epidemiological data. This result shows how rich is the information encoded in the average contact patterns of individuals, with respect to the analysis of the epidemic spreading of an infectious disease.

  8. Estimating Within-School Contact Networks to Understand Influenza Transmission

    CERN Document Server

    Potter, Gail E; Longini, Ira M; Jr.,; Halloran, M Elizabeth

    2011-01-01

    Many epidemic models approximate social contact behavior by assuming random mixing within mixing groups (e.g., homes, schools, workplaces). The effect of more realistic social network structure on epidemic parameter estimates is an open area of exploration. We develop a statistical model to estimate the social contact network within a high school using friendship network data and a contact survey. Our model includes classroom structure and longer and more frequent contacts to friends than non-friends, based on reports in the contact survey. We perform simulation studies to explore which network structures are relevant to influenza transmission. These studies yield two key findings. First, the friendship network structure important to the transmission process can be adequately represented by a dyad-independent exponential random graph model (ERGM). This means that individual-level sampled data is sufficient to characterize the entire friendship network. Second, contact behavior was adequately represented by a ...

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

    OpenAIRE

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

    2004-01-01

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

  10. Avian influenza a (H5N1: A preliminary review

    Directory of Open Access Journals (Sweden)

    Padhi S

    2004-01-01

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

  11. Efficient generation of recombinant influenza A viruses employing a new approach to overcome the genetic instability of HA segments.

    Directory of Open Access Journals (Sweden)

    Ahmed Mostafa

    Full Text Available Influenza A viruses (IAVs are the most relevant and continual source of severe infectious respiratory complications in humans and different animal species, especially poultry. Therefore, an efficient vaccination that elicits protective and neutralizing antibodies against the viral hemagglutinin (HA and neuraminidase (NA is an important strategy to counter annual epidemics or occasional pandemics. With the help of plasmid-based reverse genetics technology, it is possible that IAV vaccine strains (IVVS are rapidly generated. However, the genetic instability of some cloned HA-cDNAs after transformation into competent bacteria represents a major obstacle. Herein, we report efficient cloning strategies of different genetically volatile HA segments (H5- and H9-subtypes employing either a newly constructed vector for reverse genetics (pMKPccdB or by the use of the Escherichia coli strain HB101. Both approaches represent improved and generalizable strategies to establish functional reverse genetics systems preventing genetic changes to the cloned (HA segments of IAV facilitating more efficient rescue of recombinant IAV for basic research and vaccine development.

  12. Effectiveness of 2012-2013 influenza vaccine against influenza-like illness in general population: estimation in a French web-based cohort.

    Science.gov (United States)

    Debin, Marion; Colizza, Vittoria; Blanchon, Thierry; Hanslik, Thomas; Turbelin, Clement; Falchi, Alessandra

    2014-01-01

    Most of the methods used for estimating the influenza vaccine effectiveness (IVE) target the individuals who have an influenza-like illness (ILI) rather than virologically-proven influenza and access the healthcare system. The objective of this study was to estimate the 2012-2013 IVE in general French population, using a cohort of volunteers registered on GrippeNet.fr, an online surveillance system for ILI. The IVE estimations were obtained through a logistic regression, and analyses were also performed by focusing on at-risk population of severe influenza, and by varying inclusion period and ILI definition. Overall, 1996 individuals were included in the analyses. The corrected IVE was estimated to 49% (20 to 67) for the overall population, and 32% (0 to 58) for the at-risk population. Three covariables appeared with a significant effect on the occurrence of at least one ILI during the epidemic: the age (P = 0.045), the presence of a child in the household (P<10(-3)), and the frequency of cold/flu (P<10(-3)). Comparable results were found at epidemic peak time in the hypothesis of real-time feed of data. In this study, we proposed a novel, follow-up, web-based method to reveal seasonal vaccine effectiveness, which enables analysis in a portion of the population that is not tracked by the health care system in most VE studies.

  13. Avian Influenza: Myth or Mass Murder?

    Directory of Open Access Journals (Sweden)

    Carol Louie

    2005-01-01

    Full Text Available The purpose of the present article was to determine whether avian influenza (AI is capable of causing a pandemic. Using research from a variety of medical journals, books and texts, the present paper evaluates the probability of the AI virus becoming sufficiently virulent to pose a global threat. Previous influenza A pandemics from the past century are reviewed, focusing on the mortality rate and the qualities of the virus that distinguish it from other viruses. Each of the influenza A viruses reviewed were classified as pandemic because they met three key criteria: first, the viruses were highly pathogenic within the human population; second, the viruses were easily transmissible from person to person; and finally, the viruses were novel, such that a large proportion of the population was susceptible to infection. Information about the H5N1 subtype of AI has also been critically assessed. Evidence suggests that this AI subtype is both novel and highly pathogenic. The mortality rate from epidemics in Thailand in 2004 was as high as 66%. Clearly, this virus is aggressive. It causes a high death rate, proving that humans have a low immunity to the disease. To date, there has been little evidence to suggest that AI can spread among humans. There have been cases where the virus has transferred from birds to humans, in settings such as farms or open markets with live animal vending. If AI were to undergo a genetic reassortment that allowed itself to transmit easily from person to person, then a serious pandemic could ensue, resulting in high morbidity and mortality. Experts at the World Health Organization and the United States Centers for Disease Control and Prevention agree that AI has the potential to undergo an antigenic shift, thus triggering the next pandemic.

  14. Avian And Other Zoonotic Influenza

    Science.gov (United States)

    ... files Questions & answers Features Multimedia Contacts Avian and other zoonotic influenza Fact sheet Updated November 2016 Key ... A(H3) subtypes. Clinical features of avian and other zoonotic influenza infections in humans Avian and other ...

  15. Formation of Medical Units in Response to Epidemics in the Australian Imperial Force in Palestine 1918

    Directory of Open Access Journals (Sweden)

    Prof. G Dennis Shanks MD

    2014-06-01

    Full Text Available In the closing days of the First World War, British cavalry operations defeated the Turkish Armies in Palestine. Australian Light Horse Regiments as part of the Australian Imperial Forces (AIF were prominent in the capture of Amman, Beirut and Damascus. Epidemic infectious diseases were part of the severe desert environment faced by soldiers in the Middle East. Cholera and dysentery epidemics required reformation of medical units to emphasize mobility in an austere environment. A large epidemic of falciparum malaria coinciding with pandemic influenza shut down military operations and caused many deaths in late 1918. Three separate military medical units were formed in Egypt to address epidemic infectious diseases during mobile operations in the desert: ANZAC Field Laboratory, 5th Malaria Diagnosis Station and 7th Mobile Sanitary Section. Laboratory and preventive medicine units were critical to the military’s ability to conduct operations in the Middle East in 1918 and are likely to become vital for future missions in developing countries. As was the case in 1918, military medical units may have to be acutely restructured to control infectious disease outbreaks

  16. Atherosclerosis prevention starts in childhood: the obesity epidemic.

    Science.gov (United States)

    Medina-Ruiz, Arturo

    2011-01-01

    The atherosclerotic process begins in childhood and advances rapidly triggered by multiple genetic and environmental factors, including obesity. Obesity has reach epidemic proportions mainly by the consumption of junk food and a sedentary lifestyle. Our children spend long time inactive in front of the television and video games, further aggravated by the consumption of excessive calories of unhealthy food bombardment from TV commercials. The health related expenses of the obese is in average $1,500 annually higher than for persons with normal weight. The annual cost of diseases associated to obesity is estimated on $147 billion in the United States, a 10% of the national medical expenses. We must uncover strategies conducting to healthier lifestyles. School and home initiatives together with community and governmental efforts are necessary to stimulate our youngsters to live healthy lifestyles. The commitment of the food industry is critical to achieve the difficult goal of reducing childhood obesity to the prevalent 5% of the 1970's.

  17. Partial protection of seasonal trivalent inactivated vaccine against novel pandemic influenza A/H1N1 2009: case-control study in Mexico City

    OpenAIRE

    Garcia-Garcia, Lourdes; Valdespino-Gómez, Jose Luis; Lazcano-Ponce, Eduardo; Jimenez-Corona, Aida; Higuera-Iglesias, Anjarath; Cruz-Hervert, Pablo; Cano-Arellano, Bulmaro; Garcia-Anaya, Antonio; Ferreira-Guerrero, Elizabeth; Baez-Saldaña, Renata; Ferreyra-Reyes, Leticia; Ponce-de-León-Rosales, Samuel; Alpuche-Aranda, Celia; Rodriguez-López, Mario Henry; Perez-Padilla, Rogelio

    2009-01-01

    Objective To evaluate the association of 2008-9 seasonal trivalent inactivated vaccine with cases of influenza A/H1N1 during the epidemic in Mexico. Design Frequency matched case-control study. Setting Specialty hospital in Mexico City, March to May 2009. Participants 60 patients with laboratory confirmed influenza A/H1N1 and 180 controls with other diseases (not influenza-like illness or pneumonia) living in Mexico City or the State of Mexico and matched for age and socioeconomic status. Mai...

  18. Situational awareness of influenza activity based on multiple streams of surveillance data using multivariate dynamic linear model.

    Directory of Open Access Journals (Sweden)

    Eric H Y Lau

    Full Text Available BACKGROUND: Multiple sources of influenza surveillance data are becoming more available; however integration of these data streams for situational awareness of influenza activity is less explored. METHODS AND RESULTS: We applied multivariate time-series methods to sentinel outpatient and school absenteeism surveillance data in Hong Kong during 2004-2009. School absenteeism data and outpatient surveillance data experienced interruptions due to school holidays and changes in public health guidelines during the pandemic, including school closures and the establishment of special designated flu clinics, which in turn provided 'drop-in' fever counts surveillance data. A multivariate dynamic linear model was used to monitor influenza activity throughout epidemics based on all available data. The inferred level followed influenza activity closely at different times, while the inferred trend was less competent with low influenza activity. Correlations between inferred level and trend from the multivariate model and reference influenza activity, measured by the product of weekly laboratory influenza detection rates and weekly general practitioner influenza-like illness consultation rates, were calculated and compared with those from univariate models. Over the whole study period, there was a significantly higher correlation (ρ = 0.82, p≤0.02 for the inferred trend based on the multivariate model compared to other univariate models, while the inferred trend from the multivariate model performed as well as the best univariate model in the pre-pandemic and the pandemic period. The inferred trend and level from the multivariate model was able to match, if not outperform, the best univariate model albeit with missing data plus drop-in and drop-out of different surveillance data streams. An overall influenza index combining level and trend was constructed to demonstrate another potential use of the method. CONCLUSIONS: Our results demonstrate the

  19. Effectiveness of influenza vaccine against laboratory-confirmed influenza, in the late 2011–2012 season in Spain, among population targeted for vaccination

    Science.gov (United States)

    2013-01-01

    Background In Spain, the influenza vaccine effectiveness (VE) was estimated in the last three seasons using the observational study cycEVA conducted in the frame of the existing Spanish Influenza Sentinel Surveillance System. The objective of the study was to estimate influenza vaccine effectiveness (VE) against medically attended, laboratory-confirmed influenza-like illness (ILI) among the target groups for vaccination in Spain in the 2011–2012 season. We also studied influenza VE in the early (weeks 52/2011-7/2012) and late (weeks 8-14/2012) phases of the epidemic and according to time since vaccination. Methods Medically attended patients with ILI were systematically swabbed to collect information on exposure, laboratory outcome and confounding factors. Patients belonging to target groups for vaccination and who were swabbed 4 months, respectively, since vaccination. A decrease in VE with time since vaccination was only observed in individuals aged ≥ 65 years. Regarding the phase of the season, decreasing point estimates were only observed in the early phase, whereas very low or null estimates were obtained in the late phase for the shortest time interval. Conclusions The 2011–2012 influenza vaccine showed a low-to-moderate protective effect against medically attended, laboratory-confirmed influenza in the target groups for vaccination, in a late season and with a limited match between the vaccine and circulating strains. The suggested decrease in influenza VE with time since vaccination was mostly observed in the elderly population. The decreasing protective effect of the vaccine in the late part of the season could be related to waning vaccine protection because no viral changes were identified throughout the season. PMID:24053661

  20. Towards Future T Cell-Mediated Influenza Vaccines

    Directory of Open Access Journals (Sweden)

    Thi H. O. Nguyen

    2016-04-01

    Full Text Available Influenza A virus (IAVs infections impact significantly on global health, being particularly problematic in children, the elderly, pregnant women, indigenous populations and people with co-morbidities. Antibody-based vaccines require annual administration to combat rapidly acquired mutations modifying the surface haemagglutinin (HA and neuraminidase (NA glycoproteins. Conversely, influenza-specific CD8+ T cell responses directed at peptides derived from the more conserved internal virus proteins are known to be protective, suggesting that T cell-based vaccines may provide long-lasting cross-protection. This review outlines the importance of CD8+ T cell immunity to seasonal influenza and pandemic IAVs and summarises current vaccination strategies for inducing durable CD8+ T cell memory. Aspects of future IAV vaccine design and the use of live virus challenge in humans to establish proof of principle are also discussed.

  1. A cross-immunization model for the extinction of old influenza strains

    Science.gov (United States)

    Uekermann, Florian; Sneppen, Kim

    2016-05-01

    Given the frequent mutation of antigenic features, the constancy of genetic and antigenic diversity of influenza within a subtype is surprising. While the emergence of new strains and antigenic features is commonly attributed to selection by the human immune system, the mechanism that ensures the extinction of older strains remains controversial. To replicate this dynamics of replacement current models utilize mechanisms such as short-lived strain-transcending immunity, a direct competition for hosts, stochastic extinction or constrained antigenic evolution. Building on the idea of short-lived immunity we introduce a minimal model that exhibits the aforementioned dynamics of replacement. Our model relies only on competition due to an antigen specific immune-response in an unconstrained antigenic space. Furthermore the model explains the size of typical influenza epidemics as well as the tendency that new epidemics are associated with mutations of old antigens.

  2. Competing activation mechanisms in epidemics on networks

    CERN Document Server

    Castellano, Claudio

    2011-01-01

    In stark contrast to previous common wisdom that epidemic activity and thresholds in heterogeneous networks are dominated by the elements with the largest number of connections (the hubs), recent research has pointed out the role of the most efficient spreaders, located at the innermost, dense core of the network, in sustaining epidemic processes. Here we show that the mechanism responsible of epidemic spreading depends on the dynamical pattern of the epidemic process. For epidemics with a transient state, activity is essentially boosted by the innermost core of the network. On the contrary, epidemics allowing a steady state present a dual scenario, where either the vertex with the largest connectivity independently sustains activity and propagates it to the rest of the system, or, alternatively, the innermost core of the network collectively turns into the active state, maintaining it on a global scale. Which one of these two mechanisms actually governs the dynamics depends on the network features. In uncorr...

  3. Influenza pandemic planning in Europe.

    NARCIS (Netherlands)

    Paget, J.; Aguilera, J.F.

    2001-01-01

    The World Health Organization strongly recommends that all countries prepare in advance multidisciplinary pandemic plans to prevent and control the next influenza pandemic. We carried out a survey of influenza surveillance methods among members of the European Influenza Surveillance Schemes, EISS, w

  4. HIV/AIDS in Asia: The Shape of Epidemics and Their Molecular Epidemiology

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Asia-Pacific region is a home to 60% of the population in the world and to approximately one quarter of people with HIV/AIDS. Close to a million of people has been infected and a half million people died of AIDS annually in Asia, becoming the second largest epicenter of global AIDS epidemic. Molecular epidemiology has been useful tool to track a course of HIV spread. In-depth knowledge from the studies on molecular epidemiology elucidates the dynamics of HIV spread and the interrelationship of epidemics in the different regions in Asia.

  5. State law and influenza vaccination of health care personnel.

    Science.gov (United States)

    Stewart, Alexandra M; Cox, Marisa A

    2013-01-21

    Nosocomial influenza outbreaks, attributed to the unvaccinated health care workforce, have contributed to patient complications or death, worker illness and absenteeism, and increased economic costs to the health care system. Since 1981, the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention (CDC) has recommended that all HCP receive an annual influenza vaccination. Health care employers (HCE) have adopted various strategies to encourage health care personnel (HCP) to voluntarily receive influenza vaccination, including: sponsoring educational and promotional campaigns, increasing access to seasonal influenza vaccine, permitting the use of declination statements, and combining multiple approaches. However, these measures failed to significantly increase uptake among HCP. As a result, beginning in 2004, health care facilities and local health departments began to require certain HCP to receive influenza vaccination as a condition of employment and annually. Today, hundreds of facilities throughout the country have developed and implemented similar policies. Mandatory vaccination programs have been endorsed by professional and non-profit organizations, state health departments, and public health. These programs have been more effective at increasing coverage rates than any voluntary strategy, with some health systems reporting coverage rates up to 99.3%. Several states have enacted laws requiring HCEs to implement vaccination programs for the workforce. These laws present an example of how states will respond to threats to the public's health and constrain personal choice in order to protect vulnerable populations. This study analyzes laws in twenty states that address influenza vaccination requirements for HCP who practice in acute or long-term care facilities in the United States. The laws vary in the extent to which they incorporate the six elements of a mandatory HCP influenza vaccination program. Four of the

  6. Whole-genome sequences of influenza A(H3N2 viruses isolated from Brazilian patients with mild illness during the 2014 season

    Directory of Open Access Journals (Sweden)

    Paola Cristina Resende

    2015-02-01

    Full Text Available The influenza A(H3N2 virus has circulated worldwide for almost five decades and is the dominant subtype in most seasonal influenza epidemics, as occurred in the 2014 season in South America. In this study we evaluate five whole genome sequences of influenza A(H3N2 viruses detected in patients with mild illness collected from January-March 2014. To sequence the genomes, a new generation sequencing (NGS protocol was performed using the Ion Torrent PGM platform. In addition to analysing the common genes, haemagglutinin, neuraminidase and matrix, our work also comprised internal genes. This was the first report of a whole genome analysis with Brazilian influenza A(H3N2 samples. Considerable amino acid variability was encountered in all gene segments, demonstrating the importance of studying the internal genes. NGS of whole genomes in this study will facilitate deeper virus characterisation, contributing to the improvement of influenza strain surveillance in Brazil.

  7. Epidemic Survivability: Characterizing Networks Under Epidemic-like Failure Propagation Scenarios

    DEFF Research Database (Denmark)

    Manzano, Marc; Calle, Eusebi; Ripoll, Jordi

    2013-01-01

    in telecommunication networks has not been extensively considered, nowadays, with the increasing computation capacity and complexity of operating systems of modern network devices (routers, switches, etc.), the study of possible epidemic-like failure scenarios must be taken into account. When epidemics occur......, such as in other multiple failure scenarios, identifying the level of vulnerability offered by a network is one of the main challenges. In this paper, we present epidemic survivability, a new network measure that describes the vulnerability of each node of a network under a specific epidemic intensity. Moreover......, this metric is able to identify the set of nodes which are more vulnerable under an epidemic attack. In addition, two applications of epidemic survivability are provided. First, we introduce epidemic criticality, a novel robustness metric for epidemic failure scenarios. A case study shows the utility...

  8. SIS epidemic propagation on hypergraphs

    CERN Document Server

    Bodó, Ágnes; Simon, Péter L

    2015-01-01

    Mathematical modeling of epidemic propagation on networks is extended to hypergraphs in order to account for both the community structure and the nonlinear dependence of the infection pressure on the number of infected neighbours. The exact master equations of the propagation process are derived for an arbitrary hypergraph given by its incidence matrix. Based on these, moment closure approximation and mean-?eld models are introduced and compared to individual-based stochastic simulations. The simulation algorithm, developed for networks, is extended to hypergraphs. The e?ects of hypergraph structure and the model parameters are investigated via individual-based simulation results.

  9. Fractional Derivatives in Dengue Epidemics

    Science.gov (United States)

    Pooseh, Shakoor; Rodrigues, Helena Sofia; Torres, Delfim F. M.

    2011-09-01

    We introduce the use of fractional calculus, i.e., the use of integrals and derivatives of non-integer (arbitrary) order, in epidemiology. The proposed approach is illustrated with an outbreak of dengue disease, which is motivated by the first dengue epidemic ever recorded in the Cape Verde islands off the coast of west Africa, in 2009. Numerical simulations show that in some cases the fractional models fit better the reality when compared with the standard differential models. The classical results are obtained as particular cases by considering the order of the derivatives to take an integer value.

  10. An epidemic outbreak of cryptosporidiosis

    DEFF Research Database (Denmark)

    Mølbak, Kåre; Højlyng, Niels; Ingholt, Liselotte;

    1990-01-01

    significantly associated with diarrhea (OR = 2.79, P = 0.0006). The seasonal distribution was striking, with a peak prevalence in the beginning of the rainy season (May 17.6%) when an epidemic outbreak of diarrhea started. The prevalence was highest in children younger than 18 months, an age at which......In the first year of a prospective community study of childhood diarrhea conducted in a semiurban area in the capital of Guinea Bissau, Cryptosporidium sp. was found in 73 (6.0%) of 1216 episodes of diarrhea. The parasite was the second most prevalent intestinal parasite, and the only one...

  11. Fractional derivatives in Dengue epidemics

    CERN Document Server

    Pooseh, Shakoor; Torres, Delfim F M

    2011-01-01

    We introduce the use of fractional calculus, i.e., the use of integrals and derivatives of non-integer (arbitrary) order, in epidemiology. The proposed approach is illustrated with an outbreak of dengue disease, which is motivated by the first dengue epidemic ever recorded in the Cape Verde islands off the coast of west Africa, in 2009. Numerical simulations show that in some cases the fractional models fit better the reality when compared with the standard differential models. The classical results are obtained as particular cases by considering the order of the derivatives to take an integer value.

  12. A statistical method utilizing information of imported cases to estimate the transmissibility for an influenza pandemic

    OpenAIRE

    Chong, Ka Chun; Zee, Benny Chung Ying; Wang, Maggie Haitian

    2017-01-01

    Background In a new influenza pandemic, travel data such as arrival times of cases seeded by the originating country can be regarded as a combination of the epidemic size and the mobility networks of infections connecting the originating country with other regions. It can be a complete and timely source for estimating the basic reproduction number (R 0 ), a key indicator of disease transmissibility. Method In this study, we developed a likelihood-based method using arrival times of infected c...

  13. CNS INVOLVEMENT BY NOVEL INFLUENZA VIRUS TYPE A (H1N1, THE FIRST REPORT FROM IRAN

    Directory of Open Access Journals (Sweden)

    Ahad GHAZAVI

    2010-11-01

    Full Text Available AbstractObjectiveThis is the first report of CNS involvement by the new influenza virus (influenza A [H1N1] in Iran. The patient was a 10-year-old boy with chief complaints of fever, malaise, and cranial nerve involvement, resulting in respiratory muscle paralysis and intubation. This shows that the new influenza virus, as well as the seasonal flu, can cause neurologic complications; however, the severity of the signs and symptoms is less and the disease may resolve without complications in the case of seasonal flu. Therefore, in each patient with neurologic involvement and typical influenza signs & symptoms or a flu-like syndrome, diagnostic tests for H1N1 flu virus should be considered, especially during epidemics, and treatment with oseltamivir should be started.

  14. CCR5 deficiency predisposes to fatal outcome in influenza virus infection.

    Science.gov (United States)

    Falcon, A; Cuevas, M T; Rodriguez-Frandsen, A; Reyes, N; Pozo, F; Moreno, S; Ledesma, J; Martínez-Alarcón, J; Nieto, A; Casas, I

    2015-08-01

    Influenza epidemics affect all age groups, although children, the elderly and those with underlying medical conditions are the most severely affected. Whereas co-morbidities are present in 50% of fatal cases, 25-50% of deaths are in apparently healthy individuals. This suggests underlying genetic determinants that govern infection severity. Although some viral factors that contribute to influenza disease are known, the role of host genetic factors remains undetermined. Data for small cohorts of influenza-infected patients are contradictory regarding the potential role of chemokine receptor 5 deficiency (CCR5-Δ32 mutation, a 32 bp deletion in the CCR5 gene) in the outcome of influenza virus infection. We tested 171 respiratory samples from influenza patients (2009 pandemic) for CCR5-Δ32 and evaluated its correlation with patient mortality. CCR5-Δ32 patients (17.4%) showed a higher mortality rate than WT individuals (4.7%; P = 0.021), which indicates that CCR5-Δ32 patients are at higher risk than the normal population of a fatal outcome in influenza infection.

  15. Trends in global warming and evolution of matrix protein 2 family from influenza A virus.

    Science.gov (United States)

    Yan, Shao-Min; Wu, Guang

    2009-12-01

    The global warming is an important factor affecting the biological evolution, and the influenza is an important disease that threatens humans with possible epidemics or pandemics. In this study, we attempted to analyze the trends in global warming and evolution of matrix protein 2 family from influenza A virus, because this protein is a target of anti-flu drug, and its mutation would have significant effect on the resistance to anti-flu drugs. The evolution of matrix protein 2 of influenza A virus from 1959 to 2008 was defined using the unpredictable portion of amino-acid pair predictability. Then the trend in this evolution was compared with the trend in the global temperature, the temperature in north and south hemispheres, and the temperature in influenza A virus sampling site, and species carrying influenza A virus. The results showed the similar trends in global warming and in evolution of M2 proteins although we could not correlate them at this stage of study. The study suggested the potential impact of global warming on the evolution of proteins from influenza A virus.

  16. The effect of risk perception on the 2009 H1N1 pandemic influenza dynamics.

    Directory of Open Access Journals (Sweden)

    Piero Poletti

    Full Text Available BACKGROUND: The 2009 H1N1 pandemic influenza dynamics in Italy was characterized by a notable pattern: as it emerged from the analysis of influenza-like illness data, after an initial period (September-mid-October 2009 characterized by a slow exponential increase in the weekly incidence, a sudden and sharp increase of the growth rate was observed by mid-October. The aim here is to understand whether spontaneous behavioral changes in the population could be responsible for such a pattern of epidemic spread. METHODOLOGY/PRINCIPAL FINDINGS: In order to face this issue, a mathematical model of influenza transmission, accounting for spontaneous behavioral changes driven by cost/benefit considerations on the perceived risk of infection, is proposed and validated against empirical epidemiological data. The performed investigation revealed that an initial overestimation of the risk of infection in the general population, possibly induced by the high concern for the emergence of a new influenza pandemic, results in a pattern of spread compliant with the observed one. This finding is also supported by the analysis of antiviral drugs purchase over the epidemic period. Moreover, by assuming a generation time of 2.5 days, the initially diffuse misperception of the risk of infection led to a relatively low value of the reproductive number , which increased to in the subsequent phase of the pandemic. CONCLUSIONS/SIGNIFICANCE: This study highlights that spontaneous behavioral changes in the population, not accounted by the large majority of influenza transmission models, can not be neglected to correctly inform public health decisions. In fact, individual choices can drastically affect the epidemic spread, by altering timing, dynamics and overall number of cases.

  17. Antibody Persistence in Adults Two Years after Vaccination with an H1N1 2009 Pandemic Influenza Virus-Like Particle Vaccine.

    Directory of Open Access Journals (Sweden)

    Nuriban Valero-Pacheco

    Full Text Available The influenza virus is a human pathogen that causes epidemics every year, as well as potential pandemic outbreaks, as occurred in 2009. Vaccination has proven to be sufficient in the prevention and containment of viral spreading. In addition to the current egg-based vaccines, new and promising vaccine platforms, such as cell culture-derived vaccines that include virus-like particles (VLPs, have been developed. VLPs have been shown to be both safe and immunogenic against influenza infections. Although antibody persistence has been studied in traditional egg-based influenza vaccines, studies on antibody response durations induced by VLP influenza vaccines in humans are scarce. Here, we show that subjects vaccinated with an insect cell-derived VLP vaccine, in the midst of the 2009 H1N1 influenza pandemic outbreak in Mexico City, showed antibody persistence up to 24 months post-vaccination. Additionally, we found that subjects that reported being revaccinated with a subsequent inactivated influenza virus vaccine showed higher antibody titres to the pandemic influenza virus than those who were not revaccinated. These findings provide insights into the duration of the antibody responses elicited by an insect cell-derived pandemic influenza VLP vaccine and the possible effects of subsequent influenza vaccination on antibody persistence induced by this VLP vaccine in humans.

  18. Antibody Persistence in Adults Two Years after Vaccination with an H1N1 2009 Pandemic Influenza Virus-Like Particle Vaccine.

    Science.gov (United States)

    Valero-Pacheco, Nuriban; Pérez-Toledo, Marisol; Villasís-Keever, Miguel Ángel; Núñez-Valencia, Adriana; Boscó-Gárate, Ilka; Lozano-Dubernard, Bernardo; Lara-Puente, Horacio; Espitia, Clara; Alpuche-Aranda, Celia; Bonifaz, Laura C; Arriaga-Pizano, Lourdes; Pastelin-Palacios, Rodolfo; Isibasi, Armando; López-Macías, Constantino

    2016-01-01

    The influenza virus is a human pathogen that causes epidemics every year, as well as potential pandemic outbreaks, as occurred in 2009. Vaccination has proven to be sufficient in the prevention and containment of viral spreading. In addition to the current egg-based vaccines, new and promising vaccine platforms, such as cell culture-derived vaccines that include virus-like particles (VLPs), have been developed. VLPs have been shown to be both safe and immunogenic against influenza infections. Although antibody persistence has been studied in traditional egg-based influenza vaccines, studies on antibody response durations induced by VLP influenza vaccines in humans are scarce. Here, we show that subjects vaccinated with an insect cell-derived VLP vaccine, in the midst of the 2009 H1N1 influenza pandemic outbreak in Mexico City, showed antibody persistence up to 24 months post-vaccination. Additionally, we found that subjects that reported being revaccinated with a subsequent inactivated influenza virus vaccine showed higher antibody titres to the pandemic influenza virus than those who were not revaccinated. These findings provide insights into the duration of the antibody responses elicited by an insect cell-derived pandemic influenza VLP vaccine and the possible effects of subsequent influenza vaccination on antibody persistence induced by this VLP vaccine in humans.

  19. Antibody Persistence in Adults Two Years after Vaccination with an H1N1 2009 Pandemic Influenza Virus-Like Particle Vaccine

    Science.gov (United States)

    Villasís-Keever, Miguel Ángel; Núñez-Valencia, Adriana; Boscó-Gárate, Ilka; Lozano-Dubernard, Bernardo; Lara-Puente, Horacio; Espitia, Clara; Alpuche-Aranda, Celia; Bonifaz, Laura C.; Arriaga-Pizano, Lourdes; Pastelin-Palacios, Rodolfo; Isibasi, Armando; López-Macías, Constantino

    2016-01-01

    The influenza virus is a human pathogen that causes epidemics every year, as well as potential pandemic outbreaks, as occurred in 2009. Vaccination has proven to be sufficient in the prevention and containment of viral spreading. In addition to the current egg-based vaccines, new and promising vaccine platforms, such as cell culture-derived vaccines that include virus-like particles (VLPs), have been developed. VLPs have been shown to be both safe and immunogenic against influenza infections. Although antibody persistence has been studied in traditional egg-based influenza vaccines, studies on antibody response durations induced by VLP influenza vaccines in humans are scarce. Here, we show that subjects vaccinated with an insect cell-derived VLP vaccine, in the midst of the 2009 H1N1 influenza pandemic outbreak in Mexico City, showed antibody persistence up to 24 months post-vaccination. Additionally, we found that subjects that reported being revaccinated with a subsequent inactivated influenza virus vaccine showed higher antibody titres to the pandemic influenza virus than those who were not revaccinated. These findings provide insights into the duration of the antibody responses elicited by an insect cell-derived pandemic influenza VLP vaccine and the possible effects of subsequent influenza vaccination on antibody persistence induced by this VLP vaccine in humans. PMID:26919288

  20. Human influenza viruses and CD8(+) T cell responses.

    Science.gov (United States)

    Grant, Emma J; Quiñones-Parra, Sergio M; Clemens, E Bridie; Kedzierska, Katherine

    2016-02-01

    Influenza A viruses (IAVs) cause significant morbidity and mortality worldwide, despite new strain-specific vaccines being available annually. As IAV-specific CD8(+) T cells promote viral control in the absence of neutralizing antibodies, and can mediate cross-reactive immunity toward distinct IAVs to drive rapid recovery from both mild and severe influenza disease, there is great interest in developing a universal T cell vaccine. However, despite detailed studies in mouse models of influenza virus infection, there is still a paucity of data on human epitope-specific CD8(+) T cell responses to IAVs. This review focuses on our current understanding of human CD8(+) T cell immunity against distinct IAVs and discusses the possibility of achieving a CD8(+) T cell mediated-vaccine that protects against multiple, distinct IAV strains across diverse human populations. We also review the importance of CD8(+) T cell immunity in individuals highly susceptible to severe influenza infection, including those hospitalised with influenza, the elderly and Indigenous populations.

  1. Epidemic suicide among Micronesian adolescents.

    Science.gov (United States)

    Rubinstein, D H

    1983-01-01

    Suicide rates since 1960 in Micronesia (the U.S. Trust Territory of the Pacific Islands) have undergone an epidemic-like increase. This phenomenon is focused narrowly within the 15--24-year male age-group. Extremely high rates and culturally patterned motives and methods are now characteristic of this group. Survey research throughout Micronesia suggests that the epidemic increase in adolescent male suicide is a cohort effect among the first post-war generation. Traditional adolescent socialization in pre-war Micronesia largely involved village-level subsistence activities organized around communal lineage-houses. This extra-familial level of socialization served as a cultural solution to the residential and psychological distance post-pubertal males maintained from their domestic families. With the post-war social change in Micronesia, the communal village-level of organization has largely disintegrated, causing adolescent socialization functions to be absorbed by the nuclear family. The resulting situations of intergenerational domestic discord appear the primary social triggers for adolescent suicide. At the same time, suicides have acquired subcultural significance among male youth, giving rise to fad-like and imitative acts. A 3-year research project is now being undertaken to conduct an ethnographic study of factors contributing to adolescent stress and suicide in one Micronesian community.

  2. Disease: H00398 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available H00398 Influenza Influenza is typically a self-limiting upper respiratory disease c...aused by three types of influenza viruses: influenza A, B, and C. Influenza A and B viruses cause highly contagious disea...us is responsible for annual epidemics in humans with high mortality rates. Infectious disea

  3. Unusual dengue virus 3 epidemic in Nicaragua, 2009.

    Directory of Open Access Journals (Sweden)

    Gamaliel Gutierrez

    2011-11-01

    Full Text Available The four dengue virus serotypes (DENV1-4 cause the most prevalent mosquito-borne viral disease affecting humans worldwide. In 2009, Nicaragua experienced the largest dengue epidemic in over a decade, marked by unusual clinical presentation, as observed in two prospective studies of pediatric dengue in Managua. From August 2009-January 2010, 212 dengue cases were confirmed among 396 study participants at the National Pediatric Reference Hospital. In our parallel community-based cohort study, 170 dengue cases were recorded in 2009-10, compared to 13-65 cases in 2004-9. In both studies, significantly more patients experienced "compensated shock" (poor capillary refill plus cold extremities, tachycardia, tachypnea, and/or weak pulse in 2009-10 than in previous years (42.5% [90/212] vs. 24.7% [82/332] in the hospital study (p<0.001 and 17% [29/170] vs. 2.2% [4/181] in the cohort study (p<0.001. Signs of poor peripheral perfusion presented significantly earlier (1-2 days in 2009-10 than in previous years according to Kaplan-Meier survival analysis. In the hospital study, 19.8% of subjects were transferred to intensive care, compared to 7.1% in previous years - similar to the cohort study. DENV-3 predominated in 2008-9, 2009-10, and 2010-11, and full-length sequencing revealed no major genetic changes from 2008-9 to 2010-11. In 2008-9 and 2010-11, typical dengue was observed; only in 2009-10 was unusual presentation noted. Multivariate analysis revealed only "2009-10" as a significant risk factor for Dengue Fever with Compensated Shock. Interestingly, circulation of pandemic influenza A-H1N1 2009 in Managua was shifted such that it overlapped with the dengue epidemic. We hypothesize that prior influenza A H1N1 2009 infection may have modulated subsequent DENV infection, and initial results of an ongoing study suggest increased risk of shock among children with anti-H1N1-2009 antibodies. This study demonstrates that parameters other than serotype, viral

  4. Recent results on the spatiotemporal modelling and comparative analysis of Black Death and bubonic plague epidemics

    Science.gov (United States)

    Christakos, G.; Olea, R.A.; Yu, H.-L.

    2007-01-01

    Background: This work demonstrates the importance of spatiotemporal stochastic modelling in constructing maps of major epidemics from fragmentary information, assessing population impacts, searching for possible etiologies, and performing comparative analysis of epidemics. Methods: Based on the theory previously published by the authors and incorporating new knowledge bases, informative maps of the composite space-time distributions were generated for important characteristics of two major epidemics: Black Death (14th century Western Europe) and bubonic plague (19th-20th century Indian subcontinent). Results: The comparative spatiotemporal analysis of the epidemics led to a number of interesting findings: (1) the two epidemics exhibited certain differences in their spatiotemporal characteristics (correlation structures, trends, occurrence patterns and propagation speeds) that need to be explained by means of an interdisciplinary effort; (2) geographical epidemic indicators confirmed in a rigorous quantitative manner the partial findings of isolated reports and time series that Black Death mortality was two orders of magnitude higher than that of bubonic plague; (3) modern bubonic plague is a rural disease hitting harder the small villages in the countryside whereas Black Death was a devastating epidemic that indiscriminately attacked large urban centres and the countryside, and while the epidemic in India lasted uninterruptedly for five decades, in Western Europe it lasted three and a half years; (4) the epidemics had reverse areal extension features in response to annual seasonal variations. Temperature increase at the end of winter led to an expansion of infected geographical area for Black Death and a reduction for bubonic plague, reaching a climax at the end of spring when the infected area in Western Europe was always larger than in India. Conversely, without exception, the infected area during winter was larger for the Indian bubonic plague; (5) during the

  5. Vaccination coverage among persons with asthma -- United States, 2010-2011 influenza season.

    Science.gov (United States)

    2013-12-01

    Asthma was the most common underlying condition among persons hospitalized with pandemic influenza A (H1N1) virus infection in 2009. Although persons with asthma are not more likely than others to get influenza, influenza can make asthma symptoms worse, trigger asthma attacks, and lead to pneumonia or other complications that result in hospitalization and even death. During 1964-2010, the Advisory Committee on Immunization Practices (ACIP) recommended that all adults and children aged ≥6 months with asthma receive an influenza vaccination annually. Beginning with the 2010-11 influenza season, ACIP expanded its annual vaccination recommendation to include all persons aged ≥6 months, while emphasizing that protection of persons at higher risk for influenza-related complications continue as a focus of vaccination efforts. To provide the first update of national vaccination coverage among persons aged ≥2 years with asthma since the new ACIP recommendation, CDC analyzed data from the 2010 and 2011 National Health Interview Survey (NHIS). This report describes the results of that analysis, which indicated that influenza vaccination during the 2010-11 season among persons with asthma was 50%, up from 36% 5 years earlier. However, vaccination coverage across all age groups, including among those with health insurance, a usual place for health care, and one or more health-care visits in the past 12 months, remained well below Healthy People 2020 targets of 80% for children aged 6 months-17 years and 90% for adults aged ≥18 years who are at high risk. These findings highlight the need to educate health-care providers and persons with asthma about the importance of annual influenza vaccination.

  6. [Meningococcal epidemic in a boarding school: a rifampicin-resistant secondary case while under chemoprophylaxis].

    Science.gov (United States)

    Schubiger, G; Munzinger, J; Dudli, C; Wipfli, U

    1986-08-30

    An epidemic of meningococcal disease after an influenza outbreak in a community of 49 boys (14-18 years) and 8 adults in a boarding-school is reported. The first patient died with all symptoms of the Waterhouse-Friderichsen syndrome. Several hours later, two other boys developed severe septicemia with meningitis and meningitis respectively. N. meningitidis group B susceptible to penicillin and rifampin was isolated. Within the next 8 hours, chemoprophylaxis with rifampin (600 mg twice daily) was started and maintained for 4 days for the whole community. Throat cultures had not been obtained before prophylaxis. Ten other symptomatic boys were admitted to the hospital and treated by penicillin infusion. The results of blood and cerebrospinal fluid cultures were negative, and treatment was therefore discontinued. Five days after the death of the first boy, another boy died with full-blown Waterhouse-Friderichsen syndrome while on chemoprophylaxis. The neisseriae isolated from this patient were rifampin-resistant. Serological investigations in all patients admitted to hospital revealed the existence of concomitant epidemic infection with influenza A and B in this school. We assume that the viral infection made way for the outbreak of the meningococcal disease and for the high rate of secondary meningococcal infection. Chemoprophylaxis with rifampin should not be continued for longer than 2 to 3 days, otherwise the risk of occurrence of rifampin resistant strains of N. meningitidis increases. Hitherto such strains have rarely been isolated in clinically manifest disease.

  7. Estimation of type- and subtype-specific influenza vaccine effectiveness in Victoria, Australia using a test negative case control method, 2007-2008

    Directory of Open Access Journals (Sweden)

    Grant Kristina A

    2011-06-01

    Full Text Available Abstract Background Antigenic variation of influenza virus necessitates annual reformulation of seasonal influenza vaccines, which contain two type A strains (H1N1 and H3N2 and one type B strain. We used a test negative case control design to estimate influenza vaccine effectiveness (VE against influenza by type and subtype over two consecutive seasons in Victoria, Australia. Methods Patients presenting with influenza-like illness to general practitioners (GPs in a sentinel surveillance network during 2007 and 2008 were tested for influenza. Cases tested positive for influenza by polymerase chain reaction and controls tested negative for influenza. Vaccination status was recorded by sentinel GPs. Vaccine effectiveness was calculated as [(1 - adjusted odds ratio × 100%]. Results There were 386 eligible study participants in 2007 of whom 50% were influenza positive and 19% were vaccinated. In 2008 there were 330 eligible study participants of whom 32% were influenza positive and 17% were vaccinated. Adjusted VE against A/H3N2 influenza in 2007 was 68% (95% CI, 32 to 85% but VE against A/H1N1 (27%; 95% CI, -92 to 72% and B (84%; 95% CI, -2 to 98% were not statistically significant. In 2008, the adjusted VE estimate was positive against type B influenza (49% but negative for A/H1N1 (-88% and A/H3N2 (-66%; none was statistically significant. Conclusions Type- and subtype-specific assessment of influenza VE is needed to identify variations that cannot be differentiated from a measure of VE against all influenza. Type- and subtype-specific influenza VE estimates in Victoria in 2007 and 2008 were generally consistent with strain circulation data.

  8. Epidemics in interconnected small-world networks

    NARCIS (Netherlands)

    Liu, M.; Li, D.; Qin, P.; Liu, C.; Wang, H.; Wang, F.

    2015-01-01

    Networks can be used to describe the interconnections among individuals, which play an important role in the spread of disease. Although the small-world effect has been found to have a significant impact on epidemics in single networks, the small-world effect on epidemics in interconnected networks

  9. Modeling and simulation of epidemic spread

    DEFF Research Database (Denmark)

    Shatnawi, Maad; Lazarova-Molnar, Sanja; Zaki, Nazar

    2013-01-01

    and control such epidemics. This paper presents an overview of the epidemic spread modeling and simulation, and summarizes the main technical challenges in this field. It further investigates the most relevant recent approaches carried out towards this perspective and provides a comparison and classification...

  10. Malaria Epidemic and Drug Resistance, Djibouti

    OpenAIRE

    Rogier, Christophe; Pradines, Bruno; Bogreau, H.; Koeck, Jean-Louis; Kamil, Mohamed-Ali; Mercereau-Puijalon, Odile

    2005-01-01

    Analysis of Plasmodium falciparum isolates collected before, during, and after a 1999 malaria epidemic in Djibouti shows that, despite a high prevalence of resistance to chloroquine, the epidemic cannot be attributed to a sudden increase in drug resistance of local parasite populations.

  11. Cloned defective interfering influenza virus protects ferrets from pandemic 2009 influenza A virus and allows protective immunity to be established.

    Directory of Open Access Journals (Sweden)

    Nigel J Dimmock

    Full Text Available Influenza A viruses are a major cause of morbidity and mortality in the human population, causing epidemics in the winter, and occasional worldwide pandemics. In addition there are periodic outbreaks in domestic poultry, horses, pigs, dogs, and cats. Infections of domestic birds can be fatal for the birds and their human contacts. Control in man operates through vaccines and antivirals, but both have their limitations. In the search for an alternative treatment we have focussed on defective interfering (DI influenza A virus. Such a DI virus is superficially indistinguishable from a normal virus but has a large deletion in one of the eight RNAs that make up the viral genome. Antiviral activity resides in the deleted RNA. We have cloned one such highly active DI RNA derived from segment 1 (244 DI virus and shown earlier that intranasal administration protects mice from lethal disease caused by a number of different influenza A viruses. A more cogent model of human influenza is the ferret. Here we found that intranasal treatment with a single dose of 2 or 0.2 µg 244 RNA delivered as A/PR/8/34 virus particles protected ferrets from disease caused by pandemic virus A/California/04/09 (A/Cal; H1N1. Specifically, 244 DI virus significantly reduced fever, weight loss, respiratory symptoms, and infectious load. 244 DI RNA, the active principle, was amplified in nasal washes following infection with A/Cal, consistent with its amelioration of clinical disease. Animals that were treated with 244 DI RNA cleared infectious and DI viruses without delay. Despite the attenuation of infection and disease by DI virus, ferrets formed high levels of A/Cal-specific serum haemagglutination-inhibiting antibodies and were solidly immune to rechallenge with A/Cal. Together with earlier data from mouse studies, we conclude that 244 DI virus is a highly effective antiviral with activity potentially against all influenza A subtypes.

  12. A、B、C三型流感病毒病毒学、流行病学、临床特征和流感疫苗%Virological, Epidemiological and Clinical Features of Influenza A, B, C Virus and Influenza Vaccine

    Institute of Scientific and Technical Information of China (English)

    陈则; 方芳

    2000-01-01

    Influenza epidemics are caused by either influenza A or B virus. Influenza  C virus causes sporadic upper respiratory tract illness and is rarely associated with severe lower respiratory tract disease. There are several differences in the biological and biochemical properties among three types of influenza virus. The virological, epidemiological and clinical features of influenza A, B, and C viruses, the development of influenza vaccine and DNA vaccine were summarized.%20世纪人类遭受了4次流感大流行,数千万人失去了生命.流感病毒分A、B、C三型,对其病毒学、流行病学和临床特征,以及流感病毒传统疫苗灭活疫苗和新型疫苗核酸疫苗的研究进展作了论述。

  13. Genome evolution of novel influenza A (H1N1)viruses in humans

    Institute of Scientific and Technical Information of China (English)

    KOU Zheng; HU SongNian; LI TianXian

    2009-01-01

    The epidemic situation of A H1N1 flu arose in North America in April 2009,which rapidly expanded to three continents of Europe,Asia and Africa,with the risk ranking up to 5.Until May 13th,the flu virus of A H1N1 had spread into 33 countries and regions,with a laboratory confirmed case number of 5728,including 61 deaths.Based on IRV and EpiFluDB database,425 parts of A H1N1 flu virus sequence were achieved,followed by sequenced comparison and evolution analysis.The results showed that the current predominant A H1N1 flu virus was a kind of triple reassortment A flu virus:(i) HA,NA,MP,NP and NS originated from swine influenza virus;PB2 and PA originated from bird influenza virus;PB1 originated from human influenza virus.(ii) The origin of swine influenza virus could be subdivided as follows:HA,NP and NS originated from classic swine influenza virus of H1N1 subtype;NA and MP originated from bird origin swine influenza virus of H1N1 subtype.(iii) A H1N1 flu virus experienced no significant mutation during the epidemic spread,accompanied with no reassortment of the virus genome.In the paper,the region of the representative strains for sequence analysis (A/California/04/2009 (H1N1) and A/Mexico/4486/2009 (H1N1)) included USA and Mexico and was relatively wide,which suggested that the analysis results were convincing.

  14. [Acute encephalitis. Neuropsychiatric manifestations as expression of influenza virus infection].

    Science.gov (United States)

    Moreno-Flagge, Noris; Bayard, Vicente; Quirós, Evelia; Alonso, Tomás

    2009-01-01

    The aim is to review the encephalitis in infants and adolescents as well as its etiology, clinical manifestation, epidemiology, physiopathology, diagnostic methods and treatment, and the neuropsyquiatric signs appearing an influenza epidemy. Encephalitis is an inflammation of the central nervous system (CNS) which involves the brain. The clinical manifestations usually are: headache, fever and confusional stage. It could also be manifested as seizures, personality changes, or psiqyiatric symptoms. The clinical manifestations are related to the virus and the cell type affected in the brain. A meningitis or encephalopathy need to be ruled out. It could be present as an epidemic or isolated form, beeing this the most frequent form. It could be produced by a great variety of infections agents including virus, bacterias, fungal and parasitic. Viral causes are herpesvirus, arbovirus, rabies and enterovirus. Bacterias such as Borrelia burgdorferi, Rickettsia and Mycoplasma neumoniae. Some fungal causes are: Coccidioides immitis and Histoplasma capsulatum. More than 100 agents are related to encephalitis. The diagnosis of encephalitis is a challenge for the clinician and its infectious etiology is clear in only 40 to 70% of all cases. The diagnosis of encephalitis can be established with absolute certainty only by the microscopic examination of brain tissue. Epidemiology is related to age of the patients, geographic area, season, weather or the host immune system. Early intervention can reduce the mortality rate and sequels. We describe four patients with encephalitis and neuropsychiatric symptoms during an influenza epidemic.

  15. Dynamical correlations in the escape strategy of Influenza A virus

    Science.gov (United States)

    Taggi, L.; Colaiori, F.; Loreto, V.; Tria, F.

    2013-03-01

    The evolutionary dynamics of human Influenza A virus presents a challenging theoretical problem. An extremely high mutation rate allows the virus to escape, at each epidemic season, the host immune protection elicited by previous infections. At the same time, at each given epidemic season a single quasi-species, that is a set of closely related strains, is observed. A non-trivial relation between the genetic (i.e., at the sequence level) and the antigenic (i.e., related to the host immune response) distances can shed light into this puzzle. In this paper we introduce a model in which, in accordance with experimental observations, a simple interaction rule based on spatial correlations among point mutations dynamically defines an immunity space in the space of sequences. We investigate the static and dynamic structure of this space and we discuss how it affects the dynamics of the virus-host interaction. Interestingly we observe a staggered time structure in the virus evolution as in the real Influenza evolutionary dynamics.

  16. Sentinel surveillance of influenza-like-illness in two cities of the tropical country of Ecuador: 2006-2010.

    Directory of Open Access Journals (Sweden)

    Richard W Douce

    Full Text Available BACKGROUND: Tropical countries are thought to play an important role in the global behavior of respiratory infections such as influenza. The tropical country of Ecuador has almost no documentation of the causes of acute respiratory infections. The objectives of this study were to identify the viral agents associated with influenza like illness (ILI in Ecuador, describe what strains of influenza were circulating in the region along with their epidemiologic characteristics, and perform molecular characterization of those strains. METHODOLOGY/FINDINGS: This is a prospective surveillance study of the causes of ILI based on viral culture of oropharyngeal specimens and case report forms obtained in hospitals from two cities of Ecuador over 4 years. Out of 1,702 cases of ILI, nine viral agents were detected in 597 patients. During the time of the study, seven genetic variants of influenza circulated in Ecuador, causing six periods of increased activity. There appeared to be more heterogeneity in the cause of ILI in the tropical city of Guayaquil when compared with the Andean city of Quito. CONCLUSIONS/SIGNIFICANCE: This was the most extensive documentation of the viral causes of ILI in Ecuador to date. Influenza was a common cause of ILI in Ecuador, causing more than one outbreak per year. There was no well defined influenza season although there were periods of time when no influenza was detected alternating with epidemics of different variant strains.

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

    Science.gov (United States)

    Steel, John

    2011-10-01

    of conserved influenza virus antigens in vaccines have led to experimental vaccines based on the influenza hemagglutinin (HA) stem domain. Such vaccines have been shown to confer protection from lethal challenge in mouse models of influenza virus infection. Through further development, vaccines based on the HA stem have the potential to protect vaccinated individuals against unanticipated pandemic and epidemic influenza virus strains. Overall, recent advances in experimental vaccines and in vaccine production processes provide the potential to lower mortality and morbidity resulting from influenza infection.

  18. Inferring epidemic contact structure from phylogenetic trees.

    Directory of Open Access Journals (Sweden)

    Gabriel E Leventhal

    Full Text Available Contact structure is believed to have a large impact on epidemic spreading and consequently using networks to model such contact structure continues to gain interest in epidemiology. However, detailed knowledge of the exact contact structure underlying real epidemics is limited. Here we address the question whether the structure of the contact network leaves a detectable genetic fingerprint in the pathogen population. To this end we compare phylogenies generated by disease outbreaks in simulated populations with different types of contact networks. We find that the shape of these phylogenies strongly depends on contact structure. In particular, measures of tree imbalance allow us to quantify to what extent the contact structure underlying an epidemic deviates from a null model contact network and illustrate this in the case of random mixing. Using a phylogeny from the Swiss HIV epidemic, we show that this epidemic has a significantly more unbalanced tree than would be expected from random mixing.

  19. Epidemic centrality and the underestimated epidemic impact on network peripheral nodes

    CERN Document Server

    Sikic, Mile; Antulov-Fantulin, Nino; Stefancic, Hrvoje

    2011-01-01

    Studies of disease spreading on complex networks have provided a deep insight into the conditions of onset, dynamics and prevention of epidemics in human populations and malicious software propagation in computer networks. Identifying nodes which, when initially infected, infect the largest part of the network and ranking them according to their epidemic impact is a priority for public health policies. In simulations of the disease spreading in SIR model on studied empirical complex networks, it is shown that the ranking depends on the dynamical regime of the disease spreading. A possible mechanism leading to this dynamical dependence is illustrated in an analytically tractable example. A measure called epidemic centrality, averaging the epidemic impact over all possible disease spreading regimes, is introduced as a basis of epidemic ranking. Contrary to standard notion, the epidemic centrality of nodes with high degree, k-cores value or betweenness, which are structurally central, is comparable to epidemic c...

  20. The soft palate is an important site of adaptation for transmissible influenza viruses.

    Science.gov (United States)

    Lakdawala, Seema S; Jayaraman, Akila; Halpin, Rebecca A; Lamirande, Elaine W; Shih, Angela R; Stockwell, Timothy B; Lin, Xudong; Simenauer, Ari; Hanson, Christopher T; Vogel, Leatrice; Paskel, Myeisha; Minai, Mahnaz; Moore, Ian; Orandle, Marlene; Das, Suman R; Wentworth, David E; Sasisekharan, Ram; Subbarao, Kanta

    2015-10-01

    Influenza A viruses pose a major public health threat by causing seasonal epidemics and sporadic pandemics. Their epidemiological success relies on airborne transmission from person to person; however, the viral properties governing airborne transmission of influenza A viruses are complex. Influenza A virus infection is mediated via binding of the viral haemagglutinin (HA) to terminally attached α2,3 or α2,6 sialic acids on cell surface glycoproteins. Human influenza A viruses preferentially bind α2,6-linked sialic acids whereas avian influenza A viruses bind α2,3-linked sialic acids on complex glycans on airway epithelial cells. Historically, influenza A viruses with preferential association with α2,3-linked sialic acids have not been transmitted efficiently by the airborne route in ferrets. Here we observe efficient airborne transmission of a 2009 pandemic H1N1 (H1N1pdm) virus (A/California/07/2009) engineered to preferentially bind α2,3-linked sialic acids. Airborne transmission was associated with rapid selection of virus with a change at a single HA site that conferred binding to long-chain α2,6-linked sialic acids, without loss of α2,3-linked sialic acid binding. The transmissible virus emerged in experimentally infected ferrets within 24 hours after infection and was remarkably enriched in the soft palate, where long-chain α2,6-linked sialic acids predominate on the nasopharyngeal surface. Notably, presence of long-chain α2,6-linked sialic acids is conserved in ferret, pig and human soft palate. Using a loss-of-function approach with this one virus, we demonstrate that the ferret soft palate, a tissue not normally sampled in animal models of influenza, rapidly selects for transmissible influenza A viruses with human receptor (α2,6-linked sialic acids) preference.

  1. In vitro neuraminidase inhibitory activity of four neuraminidase inhibitors against clinical isolates of influenza virus in the Japanese 2012-2013 season.

    Science.gov (United States)

    Ikematsu, Hideyuki; Kawai, Naoki; Iwaki, Norio; Kashiwagi, Seizaburo

    2015-01-01

    The neuraminidase inhibitors (NAIs) oseltamivir phosphate (Tamiflu(®)), zanamivir (Relenza(®)), laninamivir octanoate (Inavir(®)), and peramivir (Rapiacta(®)) have been available for the treatment of influenza in Japan since 2010. The emergence of resistant virus to any of the NAIs is a great concern for influenza treatment. To assess the extent of viral resistance, we measured the 50% inhibitory concentration (IC50) of each NAI for influenza virus isolates in the 2012-2013 influenza season and compared the results to those of the 2010-2011 and 2011-2012 influenza seasons. Viral isolation of specimens obtained prior to treatment was done using Madine-Darby canine kidney cells, and the type and subtype of influenza, A(H1N1)pdm09, A(H3N2), or influenza B, was determined by RT-PCR using type- and subtype-specific primers. The IC50 was determined by a neuraminidase inhibition assay using a fluorescent substrate. A total of 329 influenza viruses were isolated:5 influenza A(H1N1)pdm09 (1.5%), 316 influenza A(H3N2) (96.1%), and 8 influenza B (2.4%). No isolate showed an IC50 value exceeding 50 nM for any of the neuraminidase inhibitors. The IC50 values for A(H3N2) and B were similar to those of the 2010-2011 and 2011-2012 seasons. No isolate showed an increased IC50 value for A(H1N1)pdm09. These results indicate that the currently epidemic influenza viruses are susceptible to all four neuraminidase inhibitors, with no trend for IC50 values to increase at present.

  2. Selecting Viruses for the Seasonal Influenza Vaccine

    Science.gov (United States)

    ... and Flu Vaccines Vaccine Effectiveness Types of Flu Vaccine Flu Shot Quadrivalent Influenza Vaccine Intradermal Influenza (Flu) Vaccination ... Cell-Based Flu Vaccines Flublok Seasonal Influenza (Flu) Vaccine Flu Vaccination by Jet Injector Adjuvant Vaccine Vaccine Virus ...

  3. Cooperative epidemics on multiplex networks

    CERN Document Server

    Azimi-Tafreshi, N

    2015-01-01

    The spread of one disease, in some cases, can stimulate the spreading of another infectious disease. Here, we treat analytically a symmetric co-infection model for spreading of two diseases on a 2-layer multiplex network. We allow layer overlapping, but we assume that each layer is random and locally loop-less. Infection with one of the diseases increases the probability to get infected by the other. Using generating function method, we calculate exactly the fraction of individuals infected with both diseases (so-called co-infected clusters) in the stationary state, as well as the epidemic spreading thresholds and the phase diagram of the model. With increasing cooperation, we observe a tricritical point and the type of transition changes from continuous to hybrid. Finally we compare the co-infected clusters in the case of co-operating diseases with the so-called viable clusters in networks with dependencies.

  4. El Nino-southern Oscillation and Lathyrism Epidemics

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    Olusegun Steven Ayodele Oluwole

    2015-09-01

    Full Text Available Epidemics of lathyrism, a neurological syndrome of spastic paraparesis, have occurredduring severe droughts in Europe, Asia, and Africa for millenia. Causation is linked toexposure to β-N-oxalyl-L-α,β-diaminopropionic acid (β-L-ODAP, a neurotoxin in Lathyrussativus. Lathyrism shares neurological features with konzo, a syndrome of predominantlyspastic paraparesis which occurs during droughts in East and Central Africa and is linked to El Nino activity. This study was done to determine the relationship of lathyrism epidemics to phases of El Nino-southern oscillation (ENSO and Pacific decadal oscillation (PDO, and to propose a model to explain why the geospatial distributions of lathyrism and konzo are non-overlapping. Contingency table of phases of ENSO and occurrence of lathyrism epidemics in Central Provinces, India from 1833–1902 was created and odds ratio was calculated. Wavelet spectra of time series of annual occurrence of lathyrism in Rewah district, India, and its coherence with ENSO and PDO from 1894–1920 were performed. Lathyrism epidemic was associated with El Nino phase of ENSO, odds ratio 378 (95 % 32–4475. Global spectra showed peaks at periodicity of 2.5 and 4.6 years for lathyrism; 2.7 and 5.0 years for PDO; and 2.5, 4.6, 7.0 years for ENSO. Spectrograms showed time-varying periodicities of 2.5–3.5 and 4.5–5.5 years for lathyrism; 2.0–3.0 and 6.5–9.0 years for ENSO; and 3.5 and 5.0 years for PDO, p < 0.0001. Spectral coherence were at 2.0–3.5 and 4.5–5.0 years for ENSO and lathyrism p < 0.0001, and 5.0 years for PDO and lathyrism p < 0.05. The droughts of El Ninos initiate dependence on Lathyrus sativus, which exposes the population to neurotoxic β-L-ODAP. Public health control of lathyrism epidemics should include development of models to forecast El Ninos and initiate food programmes in susceptible areas.

  5. Familial epidemic of meningococcal disease.

    Science.gov (United States)

    Smilović, V; Vrbanec-Megla, L; Payerl-Pal, M; Puntarić, D; Baklaić, Z

    1998-03-01

    Two closely related boys from the same house hold (Home 1), aged two and three, were affected with fulminant meningococcal sepsis known as Waterhouse-Friderichsen syndrome. Neisseria meningitidis serogorup B was isolated from their blood and cerebrospinal fluid. The two-year-old boy died one day after the onset of the disease. Epidemiological examination of contacts and pharyngeal swabs were performed in 14 persons from the household, all of them relatives of the affected children, as well as in a number of other contacts. Chemoprophylaxis with cotrimoxazole was simultaneously administered to all contacts. Family histories revealed that two contacts from the household where the patients did not live (Home 2) were inadvertently omitted. Subsequent examinations, following a report of another contagious disease (salmonelosis), revealed that these two persons were Neisseria meningitidis carriers, together with another one in the same household. The carriers most probably caused the infection of a third, five-year-old boy, the deceased boy's brother (Home 1) who also developed fulminant meningococcal sepsis. The failure to take the appropriate prophylaxis led to a prolonged carrier state in the carrier from the second household. Repeated pharyngeal swab sampling revealed two more carriers from both households that had previously been negative. Control of the epidemic was achieved after 5 weeks by repeated and controlled chemoprophylaxis with ciprofloxacin, and by repeated epidemiological examinations, disinfection, and daily health surveillance by the Sanitary Inspectorate. This extremely rare instance of a familial epidemic with three infected persons emphasizes the need for consistent chemoprophylaxis in meningococcal disease contacts.

  6. Heterogeneous edge weights promote epidemic diffusion in weighted evolving networks

    Science.gov (United States)

    Duan, Wei; Song, Zhichao; Qiu, Xiaogang

    2016-08-01

    The impact that the heterogeneities of links’ weights have on epidemic diffusion in weighted networks has received much attention. Investigating how heterogeneous edge weights affect epidemic spread is helpful for disease control. In this paper, we study a Reed-Frost epidemic model in weighted evolving networks. Our results indicate that a higher heterogeneity of edge weights leads to higher epidemic prevalence and epidemic incidence at earlier stage of epidemic diffusion in weighted evolving networks. In addition, weighted evolving scale-free networks come with a higher epidemic prevalence and epidemic incidence than unweighted scale-free networks.

  7. Seasonal influenza: Waiting for the next pandemic

    Directory of Open Access Journals (Sweden)

    Angela Clem

    2009-01-01

    Full Text Available With the ongoing cases of H1N1 influenza (aka Swine Flu occurring around the globe, seasonal influenza has a tendency to be overlooked by the media and general population as a source of illness and death. Yet, these pandemic influenza viruses arise from these seasonal influenza viruses. This article will provide an overview of seasonal influenza, its prevention and treatment, and the global surveillance system in place, used to detect the next influenza pandemic.

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

    Science.gov (United States)

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

    2014-12-01

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

  9. Mean-field analysis of an inductive reasoning game: application to influenza vaccination.

    Science.gov (United States)

    Breban, Romulus; Vardavas, Raffaele; Blower, Sally

    2007-09-01

    Recently we have introduced an inductive reasoning game of voluntary yearly vaccination to establish whether or not a population of individuals acting in their own self-interest would be able to prevent influenza epidemics. Here, we analyze our model to describe the dynamics of the collective yearly vaccination uptake. We discuss the mean-field equations of our model and first order effects of fluctuations. We explain why our model predicts that severe epidemics are periodically expected even without the introduction of pandemic strains. We find that fluctuations in the collective yearly vaccination uptake induce severe epidemics with an expected periodicity that depends on the number of independent decision makers in the population. The mean-field dynamics also reveal that there are conditions for which the dynamics become robust to the fluctuations. However, the transition between fluctuation-sensitive and fluctuation-robust dynamics occurs for biologically implausible parameters. We also analyze our model when incentive-based vaccination programs are offered. When a family-based incentive is offered, the expected periodicity of severe epidemics is increased. This results from the fact that the number of independent decision makers is reduced, increasing the effect of the fluctuations. However, incentives based on the number of years of prepayment of vaccination may yield fluctuation-robust dynamics where severe epidemics are prevented. In this case, depending on prepayment, the transition between fluctuation-sensitive and fluctuation-robust dynamics may occur for biologically plausible parameters. Our analysis provides a practical method for identifying how many years of free vaccination should be provided in order to successfully ameliorate influenza epidemics.

  10. Genetic diversity of the 2013–14 human isolates of influenza H7N9 in China

    OpenAIRE

    Farooqui, Amber; Leon, Alberto J.; Huang, Linxi; Wu, Suwu; Cai, Yingmu; Lin, Pengzhou; Chen, Weihong; Fang, Xibin; Zeng, Tiansheng; Liu, Yisu; Li ZHANG; Su, Ting; Chen, Weibin; Ghedin, Elodie; Zhu, Huachen

    2015-01-01

    Background Influenza H7N9 has become an endemic pathogen in China where circulating virus is found extensively in wild birds and domestic poultry. Two epidemic waves of Human H7N9 infections have taken place in Eastern and South Central China during the years of 2013 and 2014. In this study, we report on the first four human cases of influenza H7N9 in Shantou, Guangdong province, which occurred during the second H7N9 wave, and the subsequent analysis of the viral isolates. Methods Viral genom...

  11. Vaccination against seasonal influenza

    CERN Document Server

    SC Unit

    2009-01-01

    As every year, the Medical Service is taking part in the campaign to promote vaccination against seasonal influenza. Vaccination against seasonal influenza is especially recommended for people suffering from chronic lung, cardio-vascular or kidney conditions or diabetes, for those recovering from a serious illness or surgical operation and for everyone over the age of 65. The influenza virus is transmitted by air and contact with contaminated surfaces, hence the importance of washing hands regularly with soap and / or disinfection using a hydro-alcoholic solution. From the onset of symptoms (fever> 38°, chills, cough, muscle aches and / or joint pain, fatigue) you are strongly recommended to stay at home to avoid spreading the virus. In the present context of the influenza A (H1N1) pandemic, it is important to dissociate these two illnesses and emphasise that the two viruses and the vaccines used to combat them are quite different and that protection against one will not provide protection against the...

  12. Avian influenza control strategies

    Science.gov (United States)

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

  13. Hablemos de la Influenza

    Centers for Disease Control (CDC) Podcasts

    2010-12-08

    En la charla, un médico responde a las preguntas frecuentes sobre la vacuna contra la influenza (gripe).  Created: 12/8/2010 by Centro Nacional para la Inmunización y Enfermedades Respiratorias (NCIRD).   Date Released: 12/8/2010.

  14. Equine influenza: An overview

    Directory of Open Access Journals (Sweden)

    S. P. Waghmare

    2010-08-01

    Full Text Available Equine influenza virus is a leading cause of respiratory disease in the horses. The disease is the OIE listed disease of equines, ponies, mules and donkeys and spreads very fast. The sporadic outbreaks of the disease have occurred all over the country. Many cases have been reported in Delhi, Meerut, Saharanpur, Jaipur, Hisar, Calcutta, Ahmedabad. Nearly all the horses at Matheran (Hill station were infected with influenza. The disease has spread like wildfire at the stables of Royal Western India Turf Club (RWITC at Pune and suspended the Mumbai racing season for prolonged period of time resulting in marked economic losses. After affecting racing in Mumbai, Calcutta and New Delhi, the dreaded equine influenza has spread to Karnataka and Mysore. An outbreak of disease has marred the racing season across the country. The disease was first detected in Jammu & Kashmir before entering the central region Horses at the army polo clubs and Delhi equestrian center were also affected. As per the recent survey conducted by the army across India, it has been found that 5400 horses are infected so far, especially thoroughbred most severely. Nearly, 95 % of horses on a major farm in India are suspected of suffering from equine influenza. The government also banned inter-state movement of horses for three months to contain the disease. [Vet World 2010; 3(4.000: 194-197

  15. Receptor binding properties of human and animal H1 influenza virus isolates.

    Science.gov (United States)

    Rogers, G N; D'Souza, B L

    1989-11-01

    It has been previously reported that several human H1 influenza viruses isolated prior to 1956, in contrast to human H3 isolates which are quite specific for SA alpha 2,6Gal sequences, apparently recognize both SA alpha 2,3Gal and SA alpha 2,6Gal sequences (Rogers, G.N., and Paulson, J.C., Virology 127, 361-373, 1983). In this report human H1 isolates representative of two epidemic periods, from 1934 to 1957 and from 1977 to 1986, and H1 influenza isolated from pigs, ducks, and turkeys were compared for their ability to utilize sialyloligosaccharide structures containing terminal SA alpha 2,3Gal or SA alpha 2,6Gal sequences as receptor determinants. Five of the eight human isolates from the first epidemic period recognize both SA alpha 2,3Gal and SA alpha 2,6Gal linkages, in agreement with our previous results. Of the remaining three strains, all isolated towards the end of the first epidemic, two appear to prefer SA alpha 2,6Gal sequences while the third preferentially binds SA alpha 2,3Gal sequences. In contrast to the early isolates, 11 of 13 human strains isolated during the second epidemic period preferentially bind SA alpha 2,6Gal containing oligosaccharides. On the basis of changes in receptor binding associated with continued passage in the laboratory for some of these later strains, it seems likely that human H1 isolates preferentially bind SA alpha 2,6Gal sequences in nature, and that acquisition of SA alpha 2,3Gal-binding is associated with laboratory passage. Influenza H1 viruses isolated from pigs were predominantly SA alpha 2,6Gal-specific while those isolated from ducks were primarily SA alpha 2,3Gal-specific. Thus, as has been previously reported for H3 influenza isolates, receptor specificity for influenza H1 viruses appears to be influenced by the species from which they were isolated, human isolates binding preferentially to SA alpha 2,6Gal-containing oligosaccharides while those isolated from ducks prefer SA alpha 2,3Gal

  16. H5N6 influenza virus infection, the newest influenza

    Directory of Open Access Journals (Sweden)

    Beuy Joob

    2015-06-01

    Full Text Available The most recent new emerging infection is the H5N6 influenza virus infection. This infection has just been reported from China in early May 2014. The disease is believed to be a cross species infection. All indexed cases are from China. Of interest, the H5N6 influenza virus is the primary virus for avian. The avian H5N6 influenza virus in avian population is a low virulent strain. However, the clinical manifestation in human seems severe. In this mini-review, the authors summarize and discuss on this new emerging influenza.

  17. The mutation network for the hemagglutinin gene from the novel influenza A (H1N1) virus

    Institute of Scientific and Technical Information of China (English)

    HE YunGang; DING GuoHui; BIAN Chao; HUANG Zhong; LAN Ke; SUN Bing; WANG XueCai; LI YiXue; WANG HongYan; WANG XiaoNing; YANG Zhong; ZHONG Yang; JIN WeiRong; XIONG Hui; DAI JianXin; GUO YaJun; WANG Hao; CHE XiaoYan; WU Fan; YUAN ZhenAn; ZHANG Xi; CAO ZhiWei; ZHOU XiaoNong; ZHOU JiaHai; MA ZhiYong; TONG GuangZhi; ZHAO GuoPing; JIN Li

    2009-01-01

    A mutation network for the hemagglutinin gene (HA) of the novel type A (H1N1) influenza virus was constructed.Sequence homology analysis indicated that one HA sequence type from the viruses mainly isolated from Mexico was likely the original type in this epidemic.Based on the 658A and 1408T mutations in HA,the viruses evolving into this epidemic were divided into three categories,the Mexico,the transitional and the New York type.The three groups of viruses presented distinctive clustering features in their geographic distributions.

  18. Fifteen years of epidemiologic, virologic and syndromic influenza surveillance: A focus on type B virus and the effects of vaccine mismatch in Liguria region, Italy

    Science.gov (United States)

    Grammatico, Federico; Canepa, Paola

    2017-01-01

    ABSTRACT In order to estimate the burden of influenza and to describe the genetic evolutionary pattern and antigenic variability of type B viral strains, data deriving from 3 surveillance systems active in Liguria region, Northern Italy, were described. Since the re-emergence of the Victoria lineage in 2001, the clinical-epidemiological and syndromic surveillances demonstrated the heavy burden of influenza like illness (ILI) syndrome. Focusing on type B influenza virus, it predominated or played a relevant epidemic role in the 50% of the evaluated influenza seasons. Furthermore, the virologic surveillance demonstrated the frequent co-circulation of both lineages an heterogeneous circulation of different influenza B strains, determining a partial or complete mismatch in at least 6 influenza seasons. The undemonstrated cross-reactivity between lineages and the unpredictability of predominant lineage arose the scientific debate about the opportunity to include the quadrivalent influenza vaccine among the preventive tools to improve the protection against type B viruses. The integration of different surveillance systems highly contribute to estimate the poorly evaluated burden of type B influenza virus and help to find variants to include in the vaccine formulation. PMID:27924684

  19. [Analysis of HA and NA Genes of Influenza A H1N1 Virus in Yunnan Province during 2009-2014].

    Science.gov (United States)

    Li, Juan; Zhao, Xiaonan; Cao, Yihui; Ning, Deming; Fu, Xiaoqing; Xu, Wen

    2015-11-01

    To analyze influenza pathogen spectrum in Yunnan province during 2009-2014 years, and analyze HA and NA genes of influenza A H1N1. Analysis was made on the monitoring date of influenza cases in Yunnan province in recent 6 years, 23 strains of influenza virus of HA and NA gene was sequenced and analyzed by MEGA 5 software to construct phylogenetic tree. 4 times of influenza AH1N1 epidemic peak were monitored from 2009-2014 years in Yunnan Province, as the nucleic acid detection results of influenza A H1N1 accounted for 28.8% of the total. The sequencing result showed that HA and NA gene were divided into 3 groups, one was detected with H275Y mutation strains. Influenza A H1N1 is one of the important subtypes in Yunnan province and their genes have divided into three branches during the period of 2009-2014 years, the vast majority of influenza a H1N1 are still sensitive to neuraminidase inhibitors.

  20. Avian influenza outbreak in Turkey through health personnel's views: a qualitative study

    Directory of Open Access Journals (Sweden)

    Erbaydar Tugrul

    2007-11-01

    Full Text Available Abstract Background Avian influenza threatens public health worldwide because it is usually associated with severe illness and, consequently, a higher risk of death. During the first months of 2006, Turkey experienced its first human avian influenza epidemic. A total of 21 human cases were identified, 12 of which were confirmed by the National Institute for Medical Research. Nine of the cases, including the four fatal ones, were from the Dogubeyazit-Van region. This study aims to evaluate the efforts at the avian influenza outbreak control in the Van-Dogubeyazit region in 2006 through the experiences of health personnel. Methods We conducted in-depth interviews with seventeen key informants who took active roles during the avian influenza outbreak in East Turkey during the first months of 2006. We gathered information about the initial responses, the progress and management of the outbreak control, and the reactions of the health professionals and the public. The findings of the study are reported according to the topics that appeared through thematic analysis of the interview transcripts. Results Following the first suspected avian influenza cases, a Van Crisis Coordination Committee was formed as the coordinating and decision-making body and played an important role in the appropriate timing of decisions. The health and agriculture services could not be well coordinated owing to the lack of integrated planning in preparation for outbreak and of integrated surveillance programs. Traditional poultry practice together with the low socio-economic status of the people and the lack of health care access in the region seemed to be a major risk for animal to animal and animal to human transmission. The strengths and weaknesses of the present health system – primary health care services, national surveillance and notification systems, human resource and management – affected the inter organizational coordination during the outbreak. Open

  1. [Allergic alveolitis after influenza vaccination].

    Science.gov (United States)

    Heinrichs, D; Sennekamp, J; Kirsten, A; Kirsten, D

    2009-09-01

    Allergic alveolitis as a side effect of vaccination is very rare. We report a life-threatening complication in a female patient after influenza vaccination. The causative antigen was the influenza virus itself. Our Patient has suffered from exogen-allergic alveolitis for 12 years. Because of the guidelines of regular administration of influenza vaccination in patients with chronic pulmonary disease further research in patients with known exogen-allergic alveolitis is vitally important for the pharmaceutical drug safety.

  2. Epidemic surveillance using an electronic medical record: an empiric approach to performance improvement.

    Directory of Open Access Journals (Sweden)

    Hongzhang Zheng

    Full Text Available BACKGROUNDS: Electronic medical records (EMR form a rich repository of information that could benefit public health. We asked how structured and free-text narrative EMR data should be combined to improve epidemic surveillance for acute respiratory infections (ARI. METHODS: Eight previously characterized ARI case detection algorithms (CDA were applied to historical EMR entries to create authentic time series of daily ARI case counts (background. An epidemic model simulated influenza cases (injection. From the time of the injection, cluster-detection statistics were applied daily on paired background+injection (combined and background-only time series. This cycle was then repeated with the injection shifted to each week of the evaluation year. We computed: a the time from injection to the first statistical alarm uniquely found in the combined dataset (Detection Delay; b how often alarms originated in the background-only dataset (false-alarm rate, or FAR; and c the number of cases found within these false alarms (Caseload. For each CDA, we plotted the Detection Delay as a function of FAR or Caseload, over a broad range of alarm thresholds. RESULTS: CDAs that combined text analyses seeking ARI symptoms in clinical notes with provider-assigned diagnostic codes in order to maximize the precision rather than the sensitivity of case-detection lowered Detection Delay at any given FAR or Caseload. CONCLUSION: An empiric approach can guide the integration of EMR data into case-detection methods that improve both the timeliness and efficiency of epidemic detection.

  3. SimNest: Social Media Nested Epidemic Simulation via Online Semi-supervised Deep Learning.

    Science.gov (United States)

    Zhao, Liang; Chen, Jiangzhuo; Chen, Feng; Wang, Wei; Lu, Chang-Tien; Ramakrishnan, Naren

    2015-11-01

    Infectious disease epidemics such as influenza and Ebola pose a serious threat to global public health. It is crucial to characterize the disease and the evolution of the ongoing epidemic efficiently and accurately. Computational epidemiology can model the disease progress and underlying contact network, but suffers from the lack of real-time and fine-grained surveillance data. Social media, on the other hand, provides timely and detailed disease surveillance, but is insensible to the underlying contact network and disease model. This paper proposes a novel semi-supervised deep learning framework that integrates the strengths of computational epidemiology and social media mining techniques. Specifically, this framework learns the social media users' health states and intervention actions in real time, which are regularized by the underlying disease model and contact network. Conversely, the learned knowledge from social media can be fed into computational epidemic model to improve the efficiency and accuracy of disease diffusion modeling. We propose an online optimization algorithm to substantialize the above interactive learning process iteratively to achieve a consistent stage of the integration. The extensive experimental results demonstrated that our approach can effectively characterize the spatio-temporal disease diffusion, outperforming competing methods by a substantial margin on multiple metrics.

  4. Increasing uptake of live attenuated influenza vaccine among children in the United States, 2008-2014.

    Science.gov (United States)

    Rodgers, Loren; Pabst, Laura J; Chaves, Sandra S

    2015-01-01

    The Advisory Committee on Immunization Practices (ACIP) recommends annual influenza vaccination for all persons in the United States aged ≥6 months. On June 25, 2014, ACIP preferentially recommended live attenuated influenza vaccine (LAIV) for healthy children aged 2-8 years. Little is known about national LAIV uptake. To determine uptake of LAIV relative to inactivated influenza vaccine, we analyzed vaccination records from six immunization information system sentinel sites (approximately 10% of US population). LAIV usage increased over time in all sites. Among children 2-8 years of age vaccinated for influenza, exclusive LAIV usage in the collective sentinel site area increased from 20.1% (2008-09 season) to 38.0% (2013-14). During 2013-14, at least half of vaccinated children received LAIV in Minnesota (50.0%) and North Dakota (55.5%). Increasing LAIV usage suggests formulation acceptability, and this preexisting trend offers a favorable context for implementation of ACIP's preferential recommendation.

  5. Intensive therapy of severe complications of influenza

    Directory of Open Access Journals (Sweden)

    V. I. Kozhokaru

    2012-01-01

    Full Text Available Definition of risk factors and clinical characteristics of heavy complications of influenza for working out of criteria of polymodal intensive therapy and resuscitation was the work purpose. Results of linical supervision by 114 sick heavy form of influenza with pulmonary and extra pulmonary complications are presented. All patients suffered from virus pneumonia and sharp defeat of lungs /sharp respirator distress-syndrome (OPL/ORDS. Pulmonary complications included bacterial (85, 96 % and micotic (2, 63 % pneumonia, thrombosis of legoch arteries (19,29 %, the sharp respiratory insufficiency, caused by the polyneuropathy of a critical condition of the patient (18,42 %, the exssudative pleuritis (9,65 %, spontaneous pheumothorax (4,39 %, spontaneous pheumomediastinum (2,69 %. Extra pulmonary complications concerned the swell of brain at 100 % of patients, including, with development of a brain coma (26,32 %, sepsis (85,96 %, including, with development of septic shock (68,42 %, syndrome of disseminated intravenous coagulation (49,12 %, multyorgan insufficiency (56,14 %, sharp heavy miocarditis (22,81 %, sharp nephritic insufficiency (18,42 %, sharp hepatic insufficiency (10,52 %. Early development of pathophysiological processes (the expressed infringements of a gas exchange and an acid-base condition, a secondary immunodeficiency, heamodynamical insufficiency,m etc. leads to underestimation of severity of the patient’s condition and to failer of algorithm of polymodal intensive therapy. Development of severe complications(sepsis, septic shock, sharp respirator distress-syndrome demands expansion for epidemic of specialized medicalstructures on rendering timely intensive therapy and resuscitation.

  6. The neuropsychiatric aspects of influenza/swine flu: A selective review

    Directory of Open Access Journals (Sweden)

    Narayana Manjunatha

    2011-01-01

    Full Text Available The world witnessed the influenza virus during the seasonal epidemics and pandemics. The current strain of H1N1 (swine flu pandemic is believed to be the legacy of the influenza pandemic (1918-19. The influenza virus has been implicated in many neuropsychiatric disorders. In view of the recent pandemic, it would be interesting to review the neuropsychiatric aspects of influenza, specifically swine flu. Author used popular search engine ′PUBMED′ to search for published articles with different MeSH terms using Boolean operator (AND. Among these, a selective review of the published literature was done. Acute manifestations of swine flu varied from behavioral changes, fear of misdiagnosis during outbreak, neurological features like seizures, encephalopathy, encephalitis, transverse myelitis, aseptic meningitis, multiple sclerosis, and Guillian-Barre Syndrome. Among the chronic manifestations, schizophrenia, Parkinson′s disease, mood disorder, dementia, and mental retardation have been hypothesized. Further research is required to understand the etiological hypothesis of the chronic manifestations of influenza. The author urges neuroscientists around the world to make use of the current swine flu pandemic as an opportunity for further research.

  7. Antigenic Patterns and Evolution of the Human Influenza A (H1N1) Virus.

    Science.gov (United States)

    Liu, Mi; Zhao, Xiang; Hua, Sha; Du, Xiangjun; Peng, Yousong; Li, Xiyan; Lan, Yu; Wang, Dayan; Wu, Aiping; Shu, Yuelong; Jiang, Taijiao

    2015-09-28

    The influenza A (H1N1) virus causes seasonal epidemics that result in severe illnesses and deaths almost every year. A deep understanding of the antigenic patterns and evolution of human influenza A (H1N1) virus is extremely important for its effective surveillance and prevention. Through development of antigenicity inference method for human influenza A (H1N1), named PREDAC-H1, we systematically mapped the antigenic patterns and evolution of the human influenza A (H1N1) virus. Eight dominant antigenic clusters have been inferred for seasonal H1N1 viruses since 1977, which demonstrated sequential replacements over time with a similar pattern in Asia, Europe and North America. Among them, six clusters emerged first in Asia. As for China, three of the eight antigenic clusters were detected in South China earlier than in North China, indicating the leading role of South China in H1N1 transmission. The comprehensive view of the antigenic evolution of human influenza A (H1N1) virus can help formulate better strategy for its prevention and control.

  8. Epidemiological and virological characteristics of influenza B: results of the Global Influenza B Study

    NARCIS (Netherlands)

    Caini, S.; Huang, Q.S.; Ciblak, M.A.; Kusznierz, G.; Owen, R.; Wangchuk, S.; Henriques, C.M.; Njouom, R.; Fasce, R.A.; Yu, H.; Feng, L.; Zambon, M.; Clara, A.W.; Kosasih, H.; Puzelli, S.; Kadjo, H.A.; Emukule, G.; Heraud, J.M.; Ang, L.W.; Venter, M.; Mironenko, A.; Brammer, L.; Mai, T.Q. le; Schellevis, F.; Plotkin, S.; Paget, J.

    2015-01-01

    INTRODUCTION: Literature on influenza focuses on influenza A, despite influenza B having a large public health impact. The Global Influenza B Study aims to collect information on global epidemiology and burden of disease of influenza B since 2000. METHODS: Twenty-six countries in the Southern (n = 5

  9. Development and characterization of a panel of cross-reactive monoclonal antibodies generated using H1N1 influenza virus.

    Science.gov (United States)

    Guo, Chun-yan; Tang, Yi-gui; Qi, Zong-li; Liu, Yang; Zhao, Xiang-rong; Huo, Xue-ping; Li, Yan; Feng, Qing; Zhao, Peng-hua; Wang, Xin; Li, Yuan; Wang, Hai-fang; Hu, Jun; Zhang, Xin-jian

    2015-08-01

    To characterize the antigenic epitopes of the hemagglutinin (HA) protein of H1N1 influenza virus, a panel consisting of 84 clones of murine monoclonal antibodies (mAbs) were generated using the HA proteins from the 2009 pandemic H1N1 vaccine lysate and the seasonal influenza H1N1(A1) vaccines. Thirty-three (39%) of the 84 mAbs were found to be strain-specific, and 6 (7%) of the 84 mAbs were subtype-specific. Twenty (24%) of the 84 mAbs recognized the common HA epitopes shared by 2009 pandemic H1N1, seasonal A1 (H1N1), and A3 (H3N2) influenza viruses. Twenty-five of the 84 clones recognized the common HA epitopes shared by the 2009 pandemic H1N1, seasonal A1 (H1N1) and A3 (H3N2) human influenza viruses, and H5N1 and H9N2 avian influenza viruses. We found that of the 16 (19%) clones of the 84 mAbs panel that were cross-reactive with human respiratory pathogens, 15 were made using the HA of the seasonal A1 (H1N1) virus and 1 was made using the HA of the 2009 pandemic H1N1 influenza virus. Immunohistochemical analysis of the tissue microarray (TMA) showed that 4 of the 84 mAb clones cross-reacted with human tissue (brain and pancreas). Our results indicated that the influenza virus HA antigenic epitopes not only induce type-, subtype-, and strain-specific monoclonal antibodies against influenza A virus but also cross-reactive monoclonal antibodies against human tissues. Further investigations of these cross-reactive (heterophilic) epitopes may significantly improve our understanding of viral antigenic variation, epidemics, pathophysiologic mechanisms, and adverse effects of influenza vaccines.

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

    Directory of Open Access Journals (Sweden)

    Lisa Lucia Chenal

    2011-06-01

    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.

  11. Generation interval contraction and epidemic data analysis

    CERN Document Server

    Kenah, Eben; Robins, James M

    2008-01-01

    The generation interval is the time between the infection time of an infected person and the infection time of his or her infector. Probability density functions for generation intervals have been an important input for epidemic models and epidemic data analysis. In this paper, we specify a general stochastic SIR epidemic model and prove that the mean generation interval decreases when susceptible persons are at risk of infectious contact from multiple sources. The intuition behind this is that when a susceptible person has multiple potential infectors, there is a ``race'' to infect him or her in which only the first infectious contact leads to infection. In an epidemic, the mean generation interval contracts as the prevalence of infection increases. We call this global competition among potential infectors. When there is rapid transmission within clusters of contacts, generation interval contraction can be caused by a high local prevalence of infection even when the global prevalence is low. We call this loc...

  12. Epidemic spreading on weighted complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ye [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Liu, Chuang, E-mail: liuchuang@hznu.edu.cn [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Chu-Xu [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Zi-Ke, E-mail: zhangzike@gmail.com [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China)

    2014-01-31

    Nowadays, the emergence of online services provides various multi-relation information to support the comprehensive understanding of the epidemic spreading process. In this Letter, we consider the edge weights to represent such multi-role relations. In addition, we perform detailed analysis of two representative metrics, outbreak threshold and epidemic prevalence, on SIS and SIR models. Both theoretical and simulation results find good agreements with each other. Furthermore, experiments show that, on fully mixed networks, the weight distribution on edges would not affect the epidemic results once the average weight of whole network is fixed. This work may shed some light on the in-depth understanding of epidemic spreading on multi-relation and weighted networks.

  13. Fibroid Tumors in Women: A Hidden Epidemic?

    Science.gov (United States)

    ... Issue Past Issues Fibroid Tumors in Women: A Hidden Epidemic? Past Issues / Spring 2007 Table of Contents ... fibroids@rics.bwh.harvard.edu , or visit our Web site: www.fibroids.net . You may also write ...

  14. Some discrete SI and SIS epidemic models

    Institute of Scientific and Technical Information of China (English)

    LI Jian-quan; LOU Jie; LOU Mei-zhi

    2008-01-01

    The probability is introduced to formulate the death of individuals, the recovery of the infected individuals and incidence of epidemic disease. Based on the assumption that the number of individuals in a population is a constant, discrete-time SI and SIS epidemic models with vital dynamics are established respectively corresponding to the case that the infectives can recover from the disease or not. For these two models, the results obtained in this paper show that there is the same dynamical behavior as their corresponding continuous ones, and the threshold determining its dynamical behavior is found. Below the threshold the epidemic disease dies out eventually, above the threshold the epidemic disease becomes an endemic eventually, and the number of the infectives approaches a positive constant.

  15. Phylodynamic analysis of HIV sub-epidemics in Mochudi, Botswana

    Directory of Open Access Journals (Sweden)

    Vlad Novitsky

    2015-12-01

    Real-time HIV genotyping and breaking down local HIV epidemics into phylogenetically distinct sub-epidemics may help to reveal the structure and dynamics of HIV transmission networks in communities, and aid in the design of targeted interventions for members of the acute sub-epidemics that likely fuel local HIV/AIDS epidemics.

  16. Second Quantization Approach to Stochastic Epidemic Models

    CERN Document Server

    Mondaini, Leonardo

    2015-01-01

    We show how the standard field theoretical language based on creation and annihilation operators may be used for a straightforward derivation of closed master equations describing the population dynamics of multivariate stochastic epidemic models. In order to do that, we introduce an SIR-inspired stochastic model for hepatitis C virus epidemic, from which we obtain the time evolution of the mean number of susceptible, infected, recovered and chronically infected individuals in a population whose total size is allowed to change.

  17. Epidemics and rumours in complex networks

    CERN Document Server

    Draief, Moez

    2009-01-01

    Information propagation through peer-to-peer systems, online social systems, wireless mobile ad hoc networks and other modern structures can be modelled as an epidemic on a network of contacts. Understanding how epidemic processes interact with network topology allows us to predict ultimate course, understand phase transitions and develop strategies to control and optimise dissemination. This book is a concise introduction for applied mathematicians and computer scientists to basic models, analytical tools and mathematical and algorithmic results. Mathematical tools introduced include coupling

  18. Sublingual immunization with M2-based vaccine induces broad protective immunity against influenza.

    Directory of Open Access Journals (Sweden)

    Byoung-Shik Shim

    Full Text Available BACKGROUND: The ectodomain of matrix protein 2 (M2e of influenza A virus is a rationale target antigen candidate for the development of a universal vaccine against influenza as M2e undergoes little sequence variation amongst human influenza A strains. Vaccine-induced M2e-specific antibodies (Abs have been shown to display significant cross-protective activity in animal models. M2e-based vaccine constructs have been shown to be more protective when administered by the intranasal (i.n. route than after parenteral injection. However, i.n. administration of vaccines poses rare but serious safety issues associated with retrograde passage of inhaled antigens and adjuvants through the olfactory epithelium. In this study, we examined whether the sublingual (s.l. route could serve as a safe and effective alternative mucosal delivery route for administering a prototype M2e-based vaccine. The mechanism whereby s.l. immunization with M2e vaccine candidate induces broad protection against infection with different influenza virus subtypes was explored. METHODS AND RESULTS: A recombinant M2 protein with three tandem copies of the M2e (3M2eC was expressed in Escherichia coli. Parenteral immunizations of mice with 3M2eC induced high levels of M2e-specific serum Abs but failed to provide complete protection against lethal challenge with influenza virus. In contrast, s.l. immunization with 3M2eC was superior for inducing protection in mice. In the latter animals, protection was associated with specific Ab responses in the lungs. CONCLUSIONS: The results demonstrate that s.l. immunization with 3M2eC vaccine induced airway mucosal immune responses along with broad cross-protective immunity to influenza. These findings may contribute to the understanding of the M2-based vaccine approach to control epidemic and pandemic influenza infections.

  19. Extreme evolutionary conservation of functionally important regions in H1N1 influenza proteome.

    Directory of Open Access Journals (Sweden)

    Samantha Warren

    Full Text Available The H1N1 subtype of influenza A virus has caused two of the four documented pandemics and is responsible for seasonal epidemic outbreaks, presenting a continuous threat to public health. Co-circulating antigenically divergent influenza strains significantly complicates vaccine development and use. Here, by combining evolutionary, structural, functional, and population information about the H1N1 proteome, we seek to answer two questions: (1 do residues on the protein surfaces evolve faster than the protein core residues consistently across all proteins that constitute the influenza proteome? and (2 in spite of the rapid evolution of surface residues in influenza proteins, are there any protein regions on the protein surface that do not evolve? To answer these questions, we first built phylogenetically-aware models of the patterns of surface and interior substitutions. Employing these models, we found a single coherent pattern of faster evolution on the protein surfaces that characterizes all influenza proteins. The pattern is consistent with the events of inter-species reassortment, the worldwide introduction of the flu vaccine in the early 80's, as well as the differences caused by the geographic origins of the virus. Next, we developed an automated computational pipeline to comprehensively detect regions of the protein surface residues that were 100% conserved over multiple years and in multiple host species. We identified conserved regions on the surface of 10 influenza proteins spread across all avian, swine, and human strains; with the exception of a small group of isolated strains that affected the conservation of three proteins. Surprisingly, these regions were also unaffected by genetic variation in the pandemic 2009 H1N1 viral population data obtained from deep sequencing experiments. Finally, the conserved regions were intrinsically related to the intra-viral macromolecular interaction interfaces. Our study may provide further insights

  20. Prior population immunity reduces the expected impact of CTL-inducing vaccines for pandemic influenza control.

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    Kirsty J Bolton

    Full Text Available Vaccines that trigger an influenza-specific cytotoxic T cell (CTL response may aid pandemic control by limiting the transmission of novel influenza A viruses (IAV. We consider interventions with hypothetical CTL-inducing vaccines in a range of epidemiologically plausible pandemic scenarios. We estimate the achievable reduction in the attack rate, and, by adopting a model linking epidemic progression to the emergence of IAV variants, the opportunity for antigenic drift. We demonstrate that CTL-inducing vaccines have limited utility for modifying population-level outcomes if influenza-specific T cells found widely in adults already suppress transmission and prove difficult to enhance. Administration of CTL-inducing vaccines that are efficacious in "influenza-experienced" and "influenza-naive" hosts can likely slow transmission sufficiently to mitigate a moderate IAV pandemic. However if neutralising cross-reactive antibody to an emerging IAV are common in influenza-experienced hosts, as for the swine-variant H3N2v, boosting CTL immunity may be ineffective at reducing population spread, indicating that CTL-inducing vaccines are best used against novel subtypes such as H7N9. Unless vaccines cannot readily suppress transmission from infected hosts with naive T cell pools, targeting influenza-naive hosts is preferable. Such strategies are of enhanced benefit if naive hosts are typically intensively mixing children and when a subset of experienced hosts have pre-existing neutralising cross-reactive antibody. We show that CTL-inducing vaccination campaigns may have greater power to suppress antigenic drift than previously suggested, and targeting adults may be the optimal strategy to achieve this when the vaccination campaign does not have the power to curtail the attack rate. Our results highlight the need to design interventions based on pre-existing cellular immunity and knowledge of the host determinants of vaccine efficacy, and provide a framework