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Sample records for annual influenza epidemic

  1. Influenza: Epidemics and Pandemics

    OpenAIRE

    Markovski, Velo

    2013-01-01

    Influenza is a viral, pandemic and respiratory disease with high morbidity particular and significant mortality rate amongst humans. WHO has counted that each outbreak of epidemic is costing between 10-60 million dollars to one million citizens and each year there are between 250.000 to 500.000 deaths caused by flu. Eight RNA segments of influenza A and B viruses and seven segments of the C viruses are independently encapsulated by viral nucleoprotein. The heamagglutinin is the most important...

  2. Global Seasonal Influenza Epidemics and Climate

    Science.gov (United States)

    Tamerius, James

    2013-04-01

    Recent evidence suggests that low specific humidity conditions facilitate the transmission of the influenza virus in temperate regions and result in annual winter epidemics. However, this relationship does not account for the epidemiology of influenza in tropical and subtropical regions where epidemics often occur during the rainy season or transmit year-round without a well-defined season. We assessed the role of specific humidity and other local climatic variables on influenza virus seasonality by modeling epidemiological and climatic information from 78 study sites sampled globally. We substantiated that there are two types of environmental conditions associated with seasonal influenza epidemics: "cold-dry" and "humid-rainy". For sites where monthly average specific humidity or temperature decreases below thresholds of approximately 11-12 g/kg and 18-21 °C during the year, influenza activity peaks during the cold-dry season (i.e., winter) when specific humidity and temperature are at minimal levels. For sites where specific humidity and temperature do not decrease below these thresholds, seasonal influenza activity is more likely to peak in months when average precipitation totals are maximal and greater than 150 mm per month. Based on these findings, we develop Susceptible-Exposed-Infected-Recovered-Susceptible (SEIRS) models forced by daily weather observations of specific humidity and precipitation that simulate the diversity of seasonal influenza signals worldwide.

  3. 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

  4. Environmental predictors of seasonal influenza epidemics across temperate and tropical climates.

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    James D Tamerius

    2013-03-01

    Full Text Available Human influenza infections exhibit a strong seasonal cycle in temperate regions. Recent laboratory and epidemiological evidence suggests that low specific humidity conditions facilitate the airborne survival and transmission of the influenza virus in temperate regions, resulting in annual winter epidemics. However, this relationship is unlikely to account for the epidemiology of influenza in tropical and subtropical regions where epidemics often occur during the rainy season or transmit year-round without a well-defined season. We assessed the role of specific humidity and other local climatic variables on influenza virus seasonality by modeling epidemiological and climatic information from 78 study sites sampled globally. We substantiated that there are two types of environmental conditions associated with seasonal influenza epidemics: "cold-dry" and "humid-rainy". For sites where monthly average specific humidity or temperature decreases below thresholds of approximately 11-12 g/kg and 18-21°C during the year, influenza activity peaks during the cold-dry season (i.e., winter when specific humidity and temperature are at minimal levels. For sites where specific humidity and temperature do not decrease below these thresholds, seasonal influenza activity is more likely to peak in months when average precipitation totals are maximal and greater than 150 mm per month. These findings provide a simple climate-based model rooted in empirical data that accounts for the diversity of seasonal influenza patterns observed across temperate, subtropical and tropical climates.

  5. An Influence of Changes of Heliogeophysical Conditions on Influenza Epidemics

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    Elchin S. Babayev

    2005-01-01

    Full Text Available For purposes of studying of possible influence of the solar and geomagnetic activity on influenza diseases and epidemic, the data covering the time period of 1976-2004 is studied for the Absheron Peninsula area including the capital city Baku (the Republic of Azerbaijan with several millions of inhabitants. Period, duration, intensity and seasonal behavior of the influenza epidemic, tendency of its beginning within a solar cycle are determined. Investigations reveal that influenza epidemic usually begins 2-3 years before and / or 2-3 years after the 11-years sunspot cycle maximum. We suppose that solar activity affects the influenza epidemic mainly through geomagnetic activity (magnetic storms. The comparative analysis of years of high solar activity and both periods of originating of epidemics and pandemics on the base of antigenic formulas of influenza viruses described with the help of characters of structure of a virus (hemagglutinin and neuraminidase has revealed definite regularity in the circulation of influenza infections. Forecast method for prophylactic measures is developed for considered region. Obtained results are interpreted and compared with similar ones.

  6. Local variations in spatial synchrony of influenza epidemics.

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    James H Stark

    Full Text Available BACKGROUND: Understanding the mechanism of influenza spread across multiple geographic scales is not complete. While the mechanism of dissemination across regions and states of the United States has been described, understanding the determinants of dissemination between counties has not been elucidated. The paucity of high resolution spatial-temporal influenza incidence data to evaluate disease structure is often not available. METHODOLOGY AND FINDINGS: We report on the underlying relationship between the spread of influenza and human movement between counties of one state. Significant synchrony in the timing of epidemics exists across the entire state and decay with distance (regional correlation=62%. Synchrony as a function of population size display evidence of hierarchical spread with more synchronized epidemics occurring among the most populated counties. A gravity model describing movement between two populations is a stronger predictor of influenza spread than adult movement to and from workplaces suggesting that non-routine and leisure travel drive local epidemics. CONCLUSIONS: These findings highlight the complex nature of influenza spread across multiple geographic scales.

  7. Bayesian Analysis of Epidemics - Zombies, Influenza, and other Diseases

    OpenAIRE

    Witkowski, Caitlyn; Blais, Brian

    2013-01-01

    Mathematical models of epidemic dynamics offer significant insight into predicting and controlling infectious diseases. The dynamics of a disease model generally follow a susceptible, infected, and recovered (SIR) model, with some standard modifications. In this paper, we extend the work of Munz et.al (2009) on the application of disease dynamics to the so-called "zombie apocalypse", and then apply the identical methods to influenza dynamics. Unlike Munz et.al (2009), we include data taken fr...

  8. 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

  9. Influenza

    OpenAIRE

    Ferroni, Eliana; Jefferson, Tom

    2011-01-01

    Influenza viruses are constantly altering their antigenic structure, and every year the WHO recommends which strains of influenza should be included in vaccines. During the autumn–winter months, influenza circulates more frequently (influenza seasons), causing a greater proportion of influenza-like illness and sometimes serious seasonal epidemics.The incidence of symptoms depends on the underlying immunity of the population.

  10. Influenza

    OpenAIRE

    Jefferson, Tom

    2009-01-01

    Influenza viruses are constantly altering their antigenic structure, and every year the WHO recommends which strains of influenza should be included in vaccines. During the autumn-winter months, influenza circulates more frequently (influenza seasons), causing a greater proportion of influenza-like illness, and sometimes serious seasonal epidemics.The incidence of infection depends on the underlying immunity of the population.

  11. FluTE, a Publicly Available Stochastic Influenza Epidemic Simulation Model

    OpenAIRE

    Chao, Dennis L.; Halloran, M. Elizabeth; Valerie J Obenchain; Longini, Ira M.

    2010-01-01

    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...

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

    OpenAIRE

    Chao, Dennis L.; M. Elizabeth Halloran; Obenchain, Valerie J.; Longini, Ira M.

    2010-01-01

    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...

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

    Science.gov (United States)

    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.…

  14. Epidemic Status of Swine Influenza Virus in China

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    Kong, Weili; Ye, Jiahui; Guan, Shangsong; Liu, Jinhua; Pu, Juan

    2013-01-01

    As one of the most significant swine diseases, in recent years, swine influenza (SI) has had an immense impact on public health and has raised extensive public concerns in China. Swine are predisposed to both avian and human influenza virus infections, between that and/or swine influenza viruses, genetic reassortment could occur. This analysis aims at introducing the history of swine influenza virus, the serological epidemiology of swine influenza virus infection, the clinical details of swin...

  15. Excess mortality associated with influenza epidemics in Portugal, 1980 to 2004.

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    Baltazar Nunes

    Full Text Available BACKGROUND: Influenza epidemics have a substantial impact on human health, by increasing the mortality from pneumonia and influenza, respiratory and circulatory diseases, and all causes. This paper provides estimates of excess mortality rates associated with influenza virus circulation for 7 causes of death and 8 age groups in Portugal during the period of 1980-2004. METHODOLOGY/PRINCIPAL FINDINGS: We compiled monthly mortality time series data by age for all-cause mortality, cerebrovascular diseases, ischemic heart diseases, diseases of the respiratory system, chronic respiratory diseases, pneumonia and influenza. We also used a control outcome, deaths from injuries. Age- and cause-specific baseline mortality was modelled by the ARIMA approach; excess deaths attributable to influenza were calculated by subtracting expected deaths from observed deaths during influenza epidemic periods. Influenza was associated with a seasonal average of 24.7 all-cause excess deaths per 100,000 inhabitants, approximately 90% of which were among seniors over 65 yrs. Excess mortality was 3-6 fold higher during seasons dominated by the A(H3N2 subtype than seasons dominated by A(H1N1/B. High excess mortality impact was also seen in children under the age of four years. Seasonal excess mortality rates from all the studied causes of death were highly correlated with each other (Pearson correlation range, 0.65 to 0.95, P0.64, P<0.05. By contrast, there was no correlation with excess mortality from injuries. CONCLUSIONS/SIGNIFICANCE: Our excess mortality approach is specific to influenza virus activity and produces influenza-related mortality rates for Portugal that are similar to those published for other countries. Our results indicate that all-cause excess mortality is a robust indicator of influenza burden in Portugal, and could be used to monitor the impact of influenza epidemics in this country. Additional studies are warranted to confirm these findings in other

  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. Predicting Fluctuating Rates of Hospitalizations in Relation to Influenza Epidemics and Meteorological Factors.

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    Radia Spiga

    Full Text Available In France, rates of hospital admissions increase at the peaks of influenza epidemics. Predicting influenza-associated hospitalizations could help to anticipate increased hospital activity. The purpose of this study is to identify predictors of influenza epidemics through the analysis of meteorological data, and medical data provided by general practitioners.Historical data were collected from Meteo France, the Sentinelles network and hospitals' information systems for a period of 8 years (2007-2015. First, connections between meteorological and medical data were estimated with the Pearson correlation coefficient, Principal component analysis and classification methods (Ward and k-means. Epidemic states of tested weeks were then predicted for each week during a one-year period using linear discriminant analysis. Finally, transition probabilities between epidemic states were calculated with the Markov Chain method.High correlations were found between influenza-associated hospitalizations and the variables: Sentinelles and emergency department admissions, and anti-correlations were found between hospitalizations and each of meteorological factors applying a time lag of: -13, -12 and -32 days respectively for temperature, absolute humidity and solar radiation. Epidemic weeks were predicted accurately with the linear discriminant analysis method; however there were many misclassifications about intermediate and non-epidemic weeks. Transition probability to an epidemic state was 100% when meteorological variables were below: 2°C, 4 g/m3 and 32 W/m2, respectively for temperature, absolute humidity and solar radiation. This probability was 0% when meteorological variables were above: 6°C, 5.8g/m3 and 74W/m2.These results confirm a good correlation between influenza-associated hospitalizations, meteorological factors and general practitioner's activity, the latter being the strongest predictor of hospital activity.

  18. Predicting Fluctuating Rates of Hospitalizations in Relation to Influenza Epidemics and Meteorological Factors

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    Batton-Hubert, Mireille; Sarazin, Marianne

    2016-01-01

    Introduction In France, rates of hospital admissions increase at the peaks of influenza epidemics. Predicting influenza-associated hospitalizations could help to anticipate increased hospital activity. The purpose of this study is to identify predictors of influenza epidemics through the analysis of meteorological data, and medical data provided by general practitioners. Methods Historical data were collected from Meteo France, the Sentinelles network and hospitals’ information systems for a period of 8 years (2007–2015). First, connections between meteorological and medical data were estimated with the Pearson correlation coefficient, Principal component analysis and classification methods (Ward and k-means). Epidemic states of tested weeks were then predicted for each week during a one-year period using linear discriminant analysis. Finally, transition probabilities between epidemic states were calculated with the Markov Chain method. Results High correlations were found between influenza-associated hospitalizations and the variables: Sentinelles and emergency department admissions, and anti-correlations were found between hospitalizations and each of meteorological factors applying a time lag of: -13, -12 and -32 days respectively for temperature, absolute humidity and solar radiation. Epidemic weeks were predicted accurately with the linear discriminant analysis method; however there were many misclassifications about intermediate and non-epidemic weeks. Transition probability to an epidemic state was 100% when meteorological variables were below: 2°C, 4 g/m3 and 32 W/m2, respectively for temperature, absolute humidity and solar radiation. This probability was 0% when meteorological variables were above: 6°C, 5.8g/m3 and 74W/m2. Conclusion These results confirm a good correlation between influenza-associated hospitalizations, meteorological factors and general practitioner’s activity, the latter being the strongest predictor of hospital activity. PMID

  19. Sequential detection of influenza epidemics by the Kolmogorov-Smirnov test

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    Closas Pau

    2012-10-01

    Full Text Available Abstract Background Influenza is a well known and common human respiratory infection, causing significant morbidity and mortality every year. Despite Influenza variability, fast and reliable outbreak detection is required for health resource planning. Clinical health records, as published by the Diagnosticat database in Catalonia, host useful data for probabilistic detection of influenza outbreaks. Methods This paper proposes a statistical method to detect influenza epidemic activity. Non-epidemic incidence rates are modeled against the exponential distribution, and the maximum likelihood estimate for the decaying factor λ is calculated. The sequential detection algorithm updates the parameter as new data becomes available. Binary epidemic detection of weekly incidence rates is assessed by Kolmogorov-Smirnov test on the absolute difference between the empirical and the cumulative density function of the estimated exponential distribution with significance level 0 ≤ α ≤ 1. Results The main advantage with respect to other approaches is the adoption of a statistically meaningful test, which provides an indicator of epidemic activity with an associated probability. The detection algorithm was initiated with parameter λ0 = 3.8617 estimated from the training sequence (corresponding to non-epidemic incidence rates of the 2008-2009 influenza season and sequentially updated. Kolmogorov-Smirnov test detected the following weeks as epidemic for each influenza season: 50−10 (2008-2009 season, 38−50 (2009-2010 season, weeks 50−9 (2010-2011 season and weeks 3 to 12 for the current 2011-2012 season. Conclusions Real medical data was used to assess the validity of the approach, as well as to construct a realistic statistical model of weekly influenza incidence rates in non-epidemic periods. For the tested data, the results confirmed the ability of the algorithm to detect the start and the end of epidemic periods. In general, the proposed test could

  20. 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

  1. Modeling influenza epidemics and pandemics: insights into the future of swine flu (H1N1)

    OpenAIRE

    Blower Sally; Wagner Bradley G; Coburn Brian J

    2009-01-01

    Abstract Here we present a review of the literature of influenza modeling studies, and discuss how these models can provide insights into the future of the currently circulating novel strain of influenza A (H1N1), formerly known as swine flu. We discuss how the feasibility of controlling an epidemic critically depends on the value of the Basic Reproduction Number (R0). The R0 for novel influenza A (H1N1) has recently been estimated to be between 1.4 and 1.6. This value is below values of R0 e...

  2. Non-stationary dynamics of climate variability in synchronous influenza epidemics in Japan

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    Onozuka, Daisuke; Hagihara, Akihito

    2015-09-01

    Seasonal variation in the incidence of influenza is widely assumed. However, few studies have examined non-stationary relationships between global climate factors and influenza epidemics. We examined the monthly incidence of influenza in Fukuoka, Japan, from 2000 to 2012 using cross-wavelet coherency analysis to assess the patterns of associations between indices for the Indian Ocean Dipole (IOD) and El Niño Southern Oscillation (ENSO). The monthly incidence of influenza showed cycles of 1 year with the IOD and 2 years with ENSO indices (Multivariate, Niño 4, and Niño 3.4). These associations were non-stationary and appeared to have major influences on the synchrony of influenza epidemics. Our study provides quantitative evidence that non-stationary associations have major influences on synchrony between the monthly incidence of influenza and the dynamics of the IOD and ENSO. Our results call for the consideration of non-stationary patterns of association between influenza cases and climatic factors in early warning systems.

  3. Searching of Main Cause Leading to Severe Influenza A Virus Mutations and Consequently to Influenza Pandemics/Epidemics

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    Guang Wu

    2005-01-01

    Full Text Available The unpredictable mutations in the proteins from influenza A virus lead to the great difficulty in prevention of possible outbreak of bird flu and pandemic/epidemic of influenza. This unpredictability is due to the fact that we know little about the causes that lead to the mutations. In three of our recent studies on the hemagglutinins from influenza A virus, we unintentionally noticed the periodicity of mutations in hemagglutinins similar to the periodicity of sunspot. We calculated the amino-acid pair predictability and amino-acid distribution rank, which are developed by us over last several years and can numerically present the evolution of proteins in question, of 1217 full-length hemagglutinins from influenza A viruses. We then used the fast Fourier transform to determine the periodicity of mutations in the hemagglutinins. We compare the periodicities of mutations in influenza A virus hemagglutinins with those of solar and galactic cosmic rays and find a main periodicity of the mutations identical to that of sunspot and neutron rate (11 years/circle. Then we plot the sunspot number with respect to the historical pandemics/epidemics/non-pandemic new strains over last three centuries and compare the recorded sunspots with the historical pandemics before 1700. Both show a good agreement between sunspot activity and influenza related events. As the histories of Sun and galaxy are incomparably much longer than the history of influenza virus, the only logical deduction is that the hemagglutinin periodicities, which are identical to the periodicities of solar and galactic cosmic rays, are attribute to the solar and galactic activity. As the hemagglutinin is a sample of influenza A virus, we can logically deduce the role of migratory wild birds on the outbreak of bird flu and influenza, that is, cosmic rays are heading towards the polar regions, where more mutations occur in influenza A virus either within the wild birds or in their living

  4. Sensitivity analysis of an individual-based model for simulation of influenza epidemics.

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    Elaine O Nsoesie

    Full Text Available Individual-based epidemiology models are increasingly used in the study of influenza epidemics. Several studies on influenza dynamics and evaluation of intervention measures have used the same incubation and infectious period distribution parameters based on the natural history of influenza. A sensitivity analysis evaluating the influence of slight changes to these parameters (in addition to the transmissibility would be useful for future studies and real-time modeling during an influenza pandemic.In this study, we examined individual and joint effects of parameters and ranked parameters based on their influence on the dynamics of simulated epidemics. We also compared the sensitivity of the model across synthetic social networks for Montgomery County in Virginia and New York City (and surrounding metropolitan regions with demographic and rural-urban differences. In addition, we studied the effects of changing the mean infectious period on age-specific epidemics. The research was performed from a public health standpoint using three relevant measures: time to peak, peak infected proportion and total attack rate. We also used statistical methods in the design and analysis of the experiments. The results showed that: (i minute changes in the transmissibility and mean infectious period significantly influenced the attack rate; (ii the mean of the incubation period distribution appeared to be sufficient for determining its effects on the dynamics of epidemics; (iii the infectious period distribution had the strongest influence on the structure of the epidemic curves; (iv the sensitivity of the individual-based model was consistent across social networks investigated in this study and (v age-specific epidemics were sensitive to changes in the mean infectious period irrespective of the susceptibility of the other age groups. These findings suggest that small changes in some of the disease model parameters can significantly influence the uncertainty

  5. Domestic ducks and H5N1 influenza epidemic, Thailand.

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    Songserm, Thaweesak; Jam-on, Rungroj; Sae-Heng, Numdee; Meemak, Noppadol; Hulse-Post, Diane J; Sturm-Ramirez, Katharine M; Webster, Robert G

    2006-04-01

    In addition to causing 12 human deaths and 17 cases of human infection, the 2004 outbreak of H5N1 influenza virus in Thailand resulted in the death or slaughter of 60 million domestic fowl and the disruption of poultry production and trade. After domestic ducks were recognized as silent carriers of H5N1 influenza virus, government teams went into every village to cull flocks in which virus was detected; these team efforts markedly reduced H5N1 infection. Here we examine the pathobiology and epidemiology of H5N1 influenza virus in the 4 systems of duck raising used in Thailand in 2004. No influenza viruses were detected in ducks raised in "closed" houses with high biosecurity. However, H5N1 influenza virus was prevalent among ducks raised in "open" houses, free-ranging (grazing) ducks, and backyard ducks. PMID:16704804

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

    OpenAIRE

    Sanhong Liu; Liuyong Pang; Shigui Ruan; Xinan Zhang

    2015-01-01

    Cross-sectional surveys conducted in Thailand and China after the outbreaks of the avian influenza A H5N1 and H7N9 viruses show a high degree of awareness of human avian influenza in both urban and rural populations, a higher level of proper hygienic practice among urban residents, and in particular a dramatically reduced number of visits to live markets in urban population after the influenza A H7N9 outbreak in China in 2013. In this paper, taking into account the psychological effect toward...

  7. 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.

  8. 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

  9. Domestic Ducks and H5N1 Influenza Epidemic, Thailand

    OpenAIRE

    Songserm, Thaweesak; Jam-on, Rungroj; Sae-Heng, Numdee; Meemak, Noppadol; Hulse-Post, Diane J.; Sturm-Ramirez, Katharine M.; Webster, Robert G.

    2006-01-01

    In addition to causing 12 human deaths and 17 cases of human infection, the 2004 outbreak of H5N1 influenza virus in Thailand resulted in the death or slaughter of 60 million domestic fowl and the disruption of poultry production and trade. After domestic ducks were recognized as silent carriers of H5N1 influenza virus, government teams went into every village to cull flocks in which virus was detected; these team efforts markedly reduced H5N1 infection. Here we examine the pathobiology and e...

  10. Modelling the effects of media during an influenza epidemic

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    Collinson, Shannon; Heffernan, Jane M.

    2014-01-01

    Background Mass media is used to inform individuals regarding diseases within a population. The effects of mass media during disease outbreaks have been studied in the mathematical modelling literature, by including ‘media functions’ that affect transmission rates in mathematical epidemiological models. The choice of function to employ, however, varies, and thus, epidemic outcomes that are important to inform public health may be affected. Methods We present a survey of the disease modelling ...

  11. Comparison of filtering methods for the modeling and retrospective forecasting of influenza epidemics.

    Directory of Open Access Journals (Sweden)

    Wan Yang

    2014-04-01

    Full Text Available A variety of filtering methods enable the recursive estimation of system state variables and inference of model parameters. These methods have found application in a range of disciplines and settings, including engineering design and forecasting, and, over the last two decades, have been applied to infectious disease epidemiology. For any system of interest, the ideal filter depends on the nonlinearity and complexity of the model to which it is applied, the quality and abundance of observations being entrained, and the ultimate application (e.g. forecast, parameter estimation, etc.. Here, we compare the performance of six state-of-the-art filter methods when used to model and forecast influenza activity. Three particle filters--a basic particle filter (PF with resampling and regularization, maximum likelihood estimation via iterated filtering (MIF, and particle Markov chain Monte Carlo (pMCMC--and three ensemble filters--the ensemble Kalman filter (EnKF, the ensemble adjustment Kalman filter (EAKF, and the rank histogram filter (RHF--were used in conjunction with a humidity-forced susceptible-infectious-recovered-susceptible (SIRS model and weekly estimates of influenza incidence. The modeling frameworks, first validated with synthetic influenza epidemic data, were then applied to fit and retrospectively forecast the historical incidence time series of seven influenza epidemics during 2003-2012, for 115 cities in the United States. Results suggest that when using the SIRS model the ensemble filters and the basic PF are more capable of faithfully recreating historical influenza incidence time series, while the MIF and pMCMC do not perform as well for multimodal outbreaks. For forecast of the week with the highest influenza activity, the accuracies of the six model-filter frameworks are comparable; the three particle filters perform slightly better predicting peaks 1-5 weeks in the future; the ensemble filters are more accurate predicting peaks in

  12. Seasonal Influenza: An Overview

    Science.gov (United States)

    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…

  13. Modeling influenza epidemics and pandemics: insights into the future of swine flu (H1N1

    Directory of Open Access Journals (Sweden)

    Blower Sally

    2009-06-01

    Full Text Available Abstract Here we present a review of the literature of influenza modeling studies, and discuss how these models can provide insights into the future of the currently circulating novel strain of influenza A (H1N1, formerly known as swine flu. We discuss how the feasibility of controlling an epidemic critically depends on the value of the Basic Reproduction Number (R0. The R0 for novel influenza A (H1N1 has recently been estimated to be between 1.4 and 1.6. This value is below values of R0 estimated for the 1918–1919 pandemic strain (mean R0~2: range 1.4 to 2.8 and is comparable to R0 values estimated for seasonal strains of influenza (mean R0 1.3: range 0.9 to 2.1. By reviewing results from previous modeling studies we conclude it is theoretically possible that a pandemic of H1N1 could be contained. However it may not be feasible, even in resource-rich countries, to achieve the necessary levels of vaccination and treatment for control. As a recent modeling study has shown, a global cooperative strategy will be essential in order to control a pandemic. This strategy will require resource-rich countries to share their vaccines and antivirals with resource-constrained and resource-poor countries. We conclude our review by discussing the necessity of developing new biologically complex models. We suggest that these models should simultaneously track the transmission dynamics of multiple strains of influenza in bird, pig and human populations. Such models could be critical for identifying effective new interventions, and informing pandemic preparedness planning. Finally, we show that by modeling cross-species transmission it may be possible to predict the emergence of pandemic strains of influenza.

  14. School-Based Influenza Vaccination: Parents’ Perspectives

    OpenAIRE

    Lind, Candace; Russell, Margaret L; MacDonald, Judy; Collins, Ramona; Frank, Christine J.; Davis, Amy E.

    2014-01-01

    Background School-age children are important drivers of annual influenza epidemics yet influenza vaccination coverage of this population is low despite universal publicly funded influenza vaccination in Alberta, Canada. Immunizing children at school may potentially increase vaccine uptake. As parents are a key stakeholder group for such a program, it is important to consider their concerns. Purpose We explored parents’ perspectives on the acceptability of adding an annual influenza immunizati...

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

    Science.gov (United States)

    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. PMID:27169600

  16. Influenza Update 2000

    OpenAIRE

    Kemmerly, Sandra Abadie

    2000-01-01

    Between 30,000–40,000 Americans die annually as a result of influenza epidemics. Spread primarily through the respiratory tract, influenza's classic signs and symptoms are the abrupt onset of fever, myalgia, headache, sore throat, malaise, and nonproductive cough. The elderly and patients with underlying medical illnesses may be at risk for secondary complications. Influenza is caused by an RNA myxovirus that exists in types A, B, and C; however, the A and B types are responsible for most hum...

  17. Human vs. animal outbreaks of the 2009 swine-origin H1N1 influenza A epidemic.

    Science.gov (United States)

    Scotch, Matthew; Brownstein, John S; Vegso, Sally; Galusha, Deron; Rabinowitz, Peter

    2011-09-01

    The majority of emerging infectious diseases are zoonotic in origin, including recently emerging influenza viruses such as the 2009 swine-origin H1N1 influenza A epidemic. The epidemic that year affected both human and animal populations as it spread globally. In fact, before the end of 2009, 14 different countries reported H1N1 infected swine. In order to better understand the zoonotic nature of the epidemic and the relationship between human and animal disease surveillance data streams, we compared 2009 reports of H1N1 infection to define the temporal relationship between reported cases in animals and humans. Generally, human cases preceded animal cases at a country-level, supporting the potential of H1N1 infection to be a "reverse zoonosis", and the value of integrating human and animal disease report data. PMID:21912985

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Alternative Live-Attenuated Influenza Vaccines Based on Modifications in the Polymerase Genes Protect against Epidemic and Pandemic Flu▿

    Science.gov (United States)

    Solórzano, Alicia; Ye, Jianqiang; Pérez, Daniel R.

    2010-01-01

    Human influenza is a seasonal disease associated with significant morbidity and mortality. Influenza vaccination is the most effective means for disease prevention. We have previously shown that mutations in the PB1 and PB2 genes of the live-attenuated influenza vaccine (LAIV) from the cold-adapted (ca) influenza virus A/Ann Arbor/6/60 (H2N2) could be transferred to avian influenza viruses and produce partially attenuated viruses. We also demonstrated that avian influenza viruses carrying the PB1 and PB2 mutations could be further attenuated by stably introducing a hemagglutinin (HA) epitope tag in the PB1 gene. In this work, we wanted to determine whether these modifications would also result in attenuation of a so-called triple reassortant (TR) swine influenza virus (SIV). Thus, the TR influenza A/swine/Wisconsin/14094/99 (H3N2) virus was generated by reverse genetics and subsequently mutated in the PB1 and PB2 genes. Here we show that a combination of mutations in this TR backbone results in an attenuated virus in vitro and in vivo. Furthermore, we show the potential of our TR backbone as a vaccine that provides protection against the 2009 swine-origin pandemic influenza H1N1 virus (S-OIV) when carrying the surface of a classical swine strain. We propose that the availability of alternative backbones to the conventional ca A/Ann Arbor/6/60 LAIV strain could also be useful in epidemic and pandemic influenza and should be considered for influenza vaccine development. In addition, our data provide evidence that the use of these alternative backbones could potentially circumvent the effects of original antigenic sin (OAS) in certain circumstances. PMID:20181702

  20. Influenza: diagnosis, management, and prophylaxis.

    OpenAIRE

    WISELKA, M.

    1994-01-01

    Influenza causes enormous morbidity, death, and economic loss. Annual vaccination is strongly recommended for groups at high risk. Amantadine is effective treatment for and prophylaxis against influenza A during epidemics. New developments include rapid laboratory diagnosis, live attenuated vaccines, and antiviral drugs.

  1. Vaccination of high-risk patients against influenza : impact on primary care contact rates during epidemics. Analysis of routinely collected data

    NARCIS (Netherlands)

    Tacken, M A J B; Braspenning, J C C; Berende, A; Hak, E; De Bakker, D H; Groenewegen, P P; Grol, R P T M

    2004-01-01

    A general practice (GP) based retrospective cohort study was conducted to assess the effects of influenza vaccination on the primary care contact rate during influenza epidemics. Given the rising workload of family physicians, particularly due to ageing of the population, it is very relevant to know

  2. Effectiveness of Personal Protective Equipment and Oseltamivir Prophylaxis during Avian Influenza A (H7N7) Epidemic, the Netherlands, 2003

    OpenAIRE

    te Beest, Dennis E.; van Boven, Michiel; Bos, Marian E H; Stegeman, Arjan; Koopmans, Marion P.G.

    2010-01-01

    We analyzed the effectiveness of personal protective equipment and oseltamivir use during the 2003 avian influenza A (H7N7) epidemic in the Netherlands by linking databases containing information about farm visits, human infections, and use of oseltamivir and personal protective equipment. Using a stringent case definition, based on self-reported conjunctivitis combined with a positive hemagglutination-inhibition assay, we found that prophylactic treatment with oseltamivir significantly reduc...

  3. 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.

  4. Influenza epidemics and incidence of schizophrenia, affective disorders and mental retardation in Western Australia: no evidence of a major effect.

    Science.gov (United States)

    Morgan, V; Castle, D; Page, A; Fazio, S; Gurrin, L; Burton, P; Montgomery, P; Jablensky, A

    1997-07-25

    In-utero exposure to influenza has been implicated as a risk factor for developmental CNS damage. This study tests the hypothesis that in-utero exposure to influenza: (1) in the second gestational trimester is associated with an increased risk of schizophrenia and affective psychoses; and (2) in the first gestational trimester is associated with an increased risk of mental retardation. Analysis was confined to 1852 cases on the Western Australian psychiatric case register with ICD-9 diagnoses of schizophrenia, affective psychoses, or neurotic depression (comparison group), and 804 cases on the Intellectual Handicap Register with mental retardation that were related to 82,963 'exposed' and 32,462 'non-exposed' births between 1950 and 1960 in the total population of Western Australia. The data were examined for effects associated with six influenza epidemics in the period 1950-1960. Using relative risk ratios for individual epidemics as well as Poisson regression and a proportional hazards model to examine systematic effects for the whole period, no major effect could be identified for maternal influenza on the incidence of schizophrenia, affective psychoses and neurotic depression, despite sufficient statistical power to detect an effect. However, a possible effect was found for mental retardation in males exposed in the first and second gestational trimester. PMID:9376335

  5. FluDetWeb: an interactive web-based system for the early detection of the onset of influenza epidemics

    Directory of Open Access Journals (Sweden)

    Miralles María

    2009-07-01

    Full Text Available Abstract Background The early identification of influenza outbreaks has became a priority in public health practice. A large variety of statistical algorithms for the automated monitoring of influenza surveillance have been proposed, but most of them require not only a lot of computational effort but also operation of sometimes not-so-friendly software. Results In this paper, we introduce FluDetWeb, an implementation of a prospective influenza surveillance methodology based on a client-server architecture with a thin (web-based client application design. Users can introduce and edit their own data consisting of a series of weekly influenza incidence rates. The system returns the probability of being in an epidemic phase (via e-mail if desired. When the probability is greater than 0.5, it also returns the probability of an increase in the incidence rate during the following week. The system also provides two complementary graphs. This system has been implemented using statistical free-software (ℝ and WinBUGS, a web server environment for Java code (Tomcat and a software module created by us (Rdp responsible for managing internal tasks; the software package MySQL has been used to construct the database management system. The implementation is available on-line from: http://www.geeitema.org/meviepi/fludetweb/. Conclusion The ease of use of FluDetWeb and its on-line availability can make it a valuable tool for public health practitioners who want to obtain information about the probability that their system is in an epidemic phase. Moreover, the architecture described can also be useful for developers of systems based on computationally intensive methods.

  6. Mapping antibody epitopes of the avian H5N1 influenza virus

    OpenAIRE

    Surender Khurana; Suguitan, Amorsolo L.; Yonaira Rivera; Simmons, Cameron P.; Antonio Lanzavecchia; Federica Sallusto; Jody Manischewitz; King, Lisa R.; Kanta Subbarao; Hana Golding

    2009-01-01

    Editors' Summary Background Every winter, millions of people catch influenza, a viral infection of the airways. Most recover quickly but seasonal influenza outbreaks (epidemics) kill about half a million people annually. These epidemics occur because small but frequent changes in the viral proteins (antigens) to which the human immune system responds mean that an immune response produced one year by infection or through vaccination provides only partial protection against influenza the next y...

  7. High School Intervention for Influenza Biology and Epidemics/Pandemics: Impact on Conceptual Understanding among Adolescents

    OpenAIRE

    Dumais, Nancy; Hasni, Abdelkrim

    2009-01-01

    Understanding real-life issues such as influenza epidemiology may be of particular interest to the development of scientific knowledge and initiation of conceptual changes about viruses and their life cycles for high school students. The goal of this research project was to foster the development of adolescents' conceptual understanding of viruses and influenza biology. Thus, the project included two components: 1) pre- and posttests to determine students' conceptions about influenza biology,...

  8. 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

  9. Influenza surveillance.

    OpenAIRE

    Ghendon, Y.

    1991-01-01

    The main objectives of influenza surveillance are: collection of influenza virus isolates and analysis of their antigenic characteristics so that the most appropriate virus variants can be recommended as constituents of influenza vaccines for use during the next epidemiological season; collection and analysis of information on influenza morbidity and mortality; and earliest possible detection of influenza epidemics. Exact estimates of the specific morbidity and mortality due to influenza are ...

  10. Influenza B vaccine lineage selection-An optimized trivalent vaccine

    NARCIS (Netherlands)

    A. Mosterín Höpping (Ana); J.M. Fonville (Judith); C.A. Russell (Colin); S.L. James (Sarah ); D.R. Smith (Derek Richard)

    2016-01-01

    textabstractEpidemics of seasonal influenza viruses cause considerable morbidity and mortality each year. Various types and subtypes of influenza circulate in humans and evolve continuously such that individuals at risk of serious complications need to be vaccinated annually to keep protection up to

  11. Would school closure for the 2009 H1N1 influenza epidemic have been worth the cost?: a computational simulation of Pennsylvania

    Directory of Open Access Journals (Sweden)

    Voorhees Ronald E

    2011-05-01

    Full Text Available Abstract Background During the 2009 H1N1 influenza epidemic, policy makers debated over whether, when, and how long to close schools. While closing schools could have reduced influenza transmission thereby preventing cases, deaths, and health care costs, it may also have incurred substantial costs from increased childcare needs and lost productivity by teachers and other school employees. Methods A combination of agent-based and Monte Carlo economic simulation modeling was used to determine the cost-benefit of closing schools (vs. not closing schools for different durations (range: 1 to 8 weeks and symptomatic case incidence triggers (range: 1 to 30 for the state of Pennsylvania during the 2009 H1N1 epidemic. Different scenarios varied the basic reproductive rate (R0 from 1.2, 1.6, to 2.0 and used case-hospitalization and case-fatality rates from the 2009 epidemic. Additional analyses determined the cost per influenza case averted of implementing school closure. Results For all scenarios explored, closing schools resulted in substantially higher net costs than not closing schools. For R0 = 1.2, 1.6, and 2.0 epidemics, closing schools for 8 weeks would have resulted in median net costs of $21.0 billion (95% Range: $8.0 - $45.3 billion. The median cost per influenza case averted would have been $14,185 ($5,423 - $30,565 for R0 = 1.2, $25,253 ($9,501 - $53,461 for R0 = 1.6, and $23,483 ($8,870 - $50,926 for R0 = 2.0. Conclusions Our study suggests that closing schools during the 2009 H1N1 epidemic could have resulted in substantial costs to society as the potential costs of lost productivity and childcare could have far outweighed the cost savings in preventing influenza cases.

  12. 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.

  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. 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...

  15. Influenza A virus infection in zebrafish recapitulates mammalian infection and sensitivity to anti-influenza drug treatment

    OpenAIRE

    Gabor, Kristin A.; Michelle F. Goody; Mowel, Walter K; Breitbach, Meghan E.; Gratacap, Remi L.; P. Eckhard Witten; Kim, Carol H.

    2014-01-01

    Seasonal influenza virus infections cause annual epidemics and sporadic pandemics. These present a global health concern, resulting in substantial morbidity, mortality and economic burdens. Prevention and treatment of influenza illness is difficult due to the high mutation rate of the virus, the emergence of new virus strains and increasing antiviral resistance. Animal models of influenza infection are crucial to our gaining a better understanding of the pathogenesis of and host response to i...

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

    OpenAIRE

    Hsieh, Yu-Hsiang; Gabor D Kelen; Dugas, Andrea F.; Chen, Kuan-Fu; Rothman, Richard E.

    2013-01-01

    Introduction: Little is known regarding compliance with management guidelines for epidemic influenza 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 (CDC) guidance. Methods: We investigated all patients with a clinical diagnosis of influenza at an inner-city tertiary academic adult ED with an annual census of approximately 60,000 visits from May 2008 t...

  17. High School Intervention for Influenza Biology and Epidemics/Pandemics: Impact on Conceptual Understanding among Adolescents

    Science.gov (United States)

    Dumais, Nancy; Hasni, Abdelkrim

    2009-01-01

    Understanding real-life issues such as influenza epidemiology may be of particular interest to the development of scientific knowledge and initiation of conceptual changes about viruses and their life cycles for high school students. The goal of this research project was to foster the development of adolescents' conceptual understanding of viruses…

  18. Multi-spectral fluorescent reporter influenza viruses (Color-flu) as powerful tools for in vivo studies

    OpenAIRE

    Fukuyama, Satoshi; Katsura, Hiroaki; Zhao, Dongming; Ozawa, Makoto; Ando, Tomomi; Shoemaker, Jason E.; Ishikawa, Izumi; Yamada, Shinya; Neumann, Gabriele; Watanabe, Shinji; Kitano, Hiroaki; Kawaoka, Yoshihiro

    2015-01-01

    Seasonal influenza A viruses cause annual epidemics of respiratory disease; highly pathogenic avian H5N1 and the recently emerged H7N9 viruses cause severe infections in humans, often with fatal outcomes. Although numerous studies have addressed the pathogenicity of influenza viruses, influenza pathogenesis remains incompletely understood. Here we generate influenza viruses expressing fluorescent proteins of different colours (‘Color-flu’ viruses) to facilitate the study of viral infection in...

  19. “There Wasn't a Lot of Comforts in Those Days:” African Americans, Public Health, and the 1918 Influenza Epidemic

    OpenAIRE

    Gamble, Vanessa Northington

    2010-01-01

    When the 1918 influenza epidemic began, African American communities were already beset by many public health, medical, and social problems, including racist theories of black biological inferiority, racial barriers in medicine and public health, and poor health status. To address these problems, African Americans mounted efforts such as establishing separate hospitals and professional organizations and repudiating racist scientific theories. Contradicting prevailing theories about African Am...

  20. Slaughter of poultry during the epidemic of avian influenza in the Netherlands in 2003

    OpenAIRE

    Gerritzen, M.A.; Lambooij, E.; Stegeman, J.A.; Spruijt, B.M.

    2006-01-01

    During an outbreak of avian influenza in the Netherlands in spring 2003, the disease was controlled by destroying all the poultry on the infected farms and on all the farms within a radius of 3 km. In total, 30 million birds were killed on 1242 farms and in more than 8000 hobby flocks, by using mobile containers filled with carbon dioxide, mobile electrocution lines and by gassing whole poultry houses with carbon monoxide or carbon dioxide. Observations of these methods were used to compare t...

  1. Factors influencing psychological distress during a disease epidemic: Data from Australia's first outbreak of equine influenza

    Directory of Open Access Journals (Sweden)

    Stevens Garry J

    2008-10-01

    Full Text Available Abstract Background In 2007 Australia experienced its first outbreak of highly infectious equine influenza. Government disease control measures were put in place to control, contain, and eradicate the disease; these measures included movement restrictions and quarantining of properties. This study was conducted to assess the psycho-social impacts of this disease, and this paper reports the prevalence of, and factors influencing, psychological distress during this outbreak. Methods Data were collected using an online survey, with a link directed to the affected population via a number of industry groups. Psychological distress, as determined by the Kessler 10 Psychological Distress Scale, was the main outcome measure. Results In total, 2760 people participated in this study. Extremely high levels of non-specific psychological distress were reported by respondents in this study, with 34% reporting high psychological distress (K10 > 22, compared to levels of around 12% in the Australian general population. Analysis, using backward stepwise binary logistic regression analysis, revealed that those living in high risk infection (red zones (OR = 2.00; 95% CI: 1.57–2.55; p Conclusion Although, methodologically, this study had good internal validity, it has limited generalisability because it was not possible to identify, bound, or sample the target population accurately. However, this study is the first to collect psychological distress data from an affected population during such a disease outbreak and has potential to inform those involved in assessing the potential psychological impacts of human infectious diseases, such as pandemic influenza.

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

    Directory of Open Access Journals (Sweden)

    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. [Analysis of the Mechanism of a Three-Wave Epidemic Influenza A Virus Cvcle].

    Science.gov (United States)

    Kolesin, I D; Zhitkova, E M

    2015-01-01

    A three-wave epidemic cycle caused by a new serotype agent is simulated. The mechanism of stepwise recession in a stratum of the susceptible persons is examined. A group of asymptomatic infected individuals as well as an antigen activity index, which regulates the intensity of input streams into the groups of infected patients, are introduced into the model. Morbidity rate is additionally regulated by the virulence. The model is identified according to the observations of the three-wave passage of Hong-Kong serotype (H3N2). On the basis of the simulation results it is shown that a leading role in upgrading the virulence capacity of the agent and in replenishment of the morbid group is assigned to the asymptomatic infected individuals. PMID:26349219

  4. Alternative Live-Attenuated Influenza Vaccines Based on Modifications in the Polymerase Genes Protect against Epidemic and Pandemic Flu▿

    OpenAIRE

    Solórzano, Alicia; Ye, Jianqiang; Pérez, Daniel R.

    2010-01-01

    Human influenza is a seasonal disease associated with significant morbidity and mortality. Influenza vaccination is the most effective means for disease prevention. We have previously shown that mutations in the PB1 and PB2 genes of the live-attenuated influenza vaccine (LAIV) from the cold-adapted (ca) influenza virus A/Ann Arbor/6/60 (H2N2) could be transferred to avian influenza viruses and produce partially attenuated viruses. We also demonstrated that avian influenza viruses carrying the...

  5. Prediction of influenza B vaccine effectiveness from sequence data.

    Science.gov (United States)

    Pan, Yidan; Deem, Michael W

    2016-08-31

    Influenza is a contagious respiratory illness that causes significant human morbidity and mortality, affecting 5-15% of the population in a typical epidemic season. Human influenza epidemics are caused by types A and B, with roughly 25% of human cases due to influenza B. Influenza B is a single-stranded RNA virus with a high mutation rate, and both prior immune history and vaccination put significant pressure on the virus to evolve. Due to the high rate of viral evolution, the influenza B vaccine component of the annual influenza vaccine is updated, roughly every other year in recent years. To predict when an update to the vaccine is needed, an estimate of expected vaccine effectiveness against a range of viral strains is required. We here introduce a method to measure antigenic distance between the influenza B vaccine and circulating viral strains. The measure correlates well with effectiveness of the influenza B component of the annual vaccine in humans between 1979 and 2014. We discuss how this measure of antigenic distance may be used in the context of annual influenza vaccine design and prediction of vaccine effectiveness. PMID:27473305

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

    Directory of Open Access Journals (Sweden)

    Martha I Nelson

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

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

    OpenAIRE

    Ye, Jianqiang; Shao, Hongxia; Daniel R Perez

    2012-01-01

    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 re...

  8. Multi-agent modeling of the South Korean avian influenza epidemic

    Directory of Open Access Journals (Sweden)

    Kim Taehyong

    2010-08-01

    Full Text Available Abstract Background Several highly pathogenic avian influenza (AI outbreaks have been reported over the past decade. South Korea recently faced AI outbreaks whose economic impact was estimated to be 6.3 billion dollars, equivalent to nearly 50% of the profit generated by the poultry-related industries in 2008. In addition, AI is threatening to cause a human pandemic of potentially devastating proportions. Several studies show that a stochastic simulation model can be used to plan an efficient containment strategy on an emerging influenza. Efficient control of AI outbreaks based on such simulation studies could be an important strategy in minimizing its adverse economic and public health impacts. Methods We constructed a spatio-temporal multi-agent model of chickens and ducks in poultry farms in South Korea. The spatial domain, comprised of 76 (37.5 km × 37.5 km unit squares, approximated the size and scale of South Korea. In this spatial domain, we introduced 3,039 poultry flocks (corresponding to 2,231 flocks of chickens and 808 flocks of ducks whose spatial distribution was proportional to the number of birds in each province. The model parameterizes the properties and dynamic behaviors of birds in poultry farms and quarantine plans and included infection probability, incubation period, interactions among birds, and quarantine region. Results We conducted sensitivity analysis for the different parameters in the model. Our study shows that the quarantine plan with well-chosen values of parameters is critical for minimize loss of poultry flocks in an AI outbreak. Specifically, the aggressive culling plan of infected poultry farms over 18.75 km radius range is unlikely to be effective, resulting in higher fractions of unnecessarily culled poultry flocks and the weak culling plan is also unlikely to be effective, resulting in higher fractions of infected poultry flocks. Conclusions Our results show that a prepared response with targeted

  9. Annual influenza vaccination: coverage and attitudes of primary care staff in Australia

    Science.gov (United States)

    Ward, Kirsten; Seale, Holly; Zwar, Nicholas; Leask, Julie; MacIntyre, C. Raina

    2010-01-01

    Please cite this paper as: Ward et al. (2011) Annual influenza vaccination: coverage and attitudes of primary care staff in Australia. Influenza and Other Respiratory Viruses 5(2), 135–141. Background  Annual influenza vaccination is recommended for all Australian health care workers (HCWs) including those working in primary health care. There is limited published data on coverage, workplace provision, attitudes and personal barriers to influenza vaccination amongst primary health care staff. The aim of this study was to contribute to the limited literature base in this important area by investigating these issues in the primary health care setting in New South Wales (NSW), Australia. Methods  A postal survey was sent to general practitioners (GPs) and practice nurses (PNs) from inner city, semi‐urban and rural areas of NSW, Australia. There were 139 responses in total (response rate 36%) from 79 GPs (response rate 30%) and 60 PNs (response rate 46%). Results  Reported influenza vaccination coverage in both 2007 and 2008 was greater than 70%, with GPs reporting higher coverage than PNs in both years. The main barriers identified were lack of awareness of vaccination recommendations for general practice staff and concern about adverse effects from the vaccine. Conclusions  Rates of influenza vaccination coverage reported in this study were higher than in previous studies of hospital and institutional HCWs, though it is possible that the study design may have contributed to these higher results. Nevertheless, these findings highlight that more needs to be done to understand barriers to vaccination in this group, to inform the development of appropriate strategies to increase vaccination coverage in primary health care staff, with a special focus on PNs. PMID:21306577

  10. 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

  11. Universal Influenza Vaccines, a Dream to Be Realized Soon

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    Han Zhang

    2014-04-01

    Full Text Available Due to frequent viral antigenic change, current influenza vaccines need to be re-formulated annually to match the circulating strains for battling seasonal influenza epidemics. These vaccines are also ineffective in preventing occasional outbreaks of new influenza pandemic viruses. All these challenges call for the development of universal influenza vaccines capable of conferring broad cross-protection against multiple subtypes of influenza A viruses. Facilitated by the advancement in modern molecular biology, delicate antigen design becomes one of the most effective factors for fulfilling such goals. Conserved epitopes residing in virus surface proteins including influenza matrix protein 2 and the stalk domain of the hemagglutinin draw general interest for improved antigen design. The present review summarizes the recent progress in such endeavors and also covers the encouraging progress in integrated antigen/adjuvant delivery and controlled release technology that facilitate the development of an affordable universal influenza vaccine.

  12. Emergence of truncated PB1-F2 protein of H3N2 influenza virus during its epidemic period in Jiangsu Province, China

    Institute of Scientific and Technical Information of China (English)

    Wei Pingmin; Luo Pengfei; Li wei; Zi Hairong; Qi Xian; Deng Fei; Qin Yuanfang

    2014-01-01

    Background PB1-F2 protein has been proven to increase the pathogenicity of influenza A virus (IAV) strains in primary infection and in secondary bacterial infection.It can also regulate the activity of viral polymerase.However,it was shown in another retrospective study that a portion of IAVs do not express full-length PB1-F2 protein during virus development; different kinds of stop codons cause exits in the open reading frames and form PB1-F2 gene products with the corresponding genotypes.Truncated PB1-F2 in human H3N2 IAVs has long been detected in North America but its evolution in China is still unclear.Methods Influenza-like illnesses (ILls) from the whole of Jiangsu Province were collected and inspected to determine the type and subtype of the viruses.A portion of isolates collected in the epidemic period were selected as samples for later whole-genome sequencing,and the exact sequences were determined and analyzed.Results H3N2 influenza virus was one of the epidemical strains which had been prevalent during 2009-2010,in Jiangsu.Five H3N2 isolates with truncated PB1-F2 protein (25aa) were detected in influenza samples from Nanjing and Xuzhou,while seven similar H3N2 isolates were also reported in Niigata,Japan.Conclusion This emergence indicates the possibility that there has been transmission of the H3N2 virus between the two countries.

  13. Rapid Semiautomated Subtyping of Influenza Virus Species during the 2009 Swine Origin Influenza A H1N1 Virus Epidemic in Milwaukee, Wisconsin▿

    OpenAIRE

    Bose, Michael E; Beck, Eric T.; Ledeboer, Nate; Kehl, Sue C.; Jurgens, Lisa A.; Patitucci, Teresa; Witt, Lorraine; LaGue, Elizabeth; Darga, Patrick; He, Jie; Fan, Jiang; Kumar, Swati; Kelly J. Henrickson

    2009-01-01

    In the spring of 2009, a novel influenza A (H1N1) virus (swine origin influenza virus [S-OIV]) emerged and began causing a large outbreak of illness in Milwaukee, WI. Our group at the Midwest Respiratory Virus Program laboratory developed a semiautomated real-time multiplex reverse transcription-PCR assay (Seasonal), employing the NucliSENS easyMAG system (bioMérieux, Durham, NC) and a Raider thermocycler (HandyLab Inc., Ann Arbor, MI), that typed influenza A virus, influenza B virus, and res...

  14. [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. PMID:22390048

  15. Modelo para estimación del comportamiento epidémico de la influenza A (H1N1 en México Model to estimate epidemic patterns of influenza A (H1N1 in Mexico

    Directory of Open Access Journals (Sweden)

    Estela Navarro-Robles

    2012-04-01

    Full Text Available OBJETIVO: Aplicar un modelo matemático para estimar el comportamiento epidémico de la influenza A (H1N1 en México durante las etapas de aplicación y suspensión de medidas para mitigar la epidemia. MÉTODOS: Se estimó el número reproductivo efectivo (R para cada estado de México mediante el modelo SIR (individuos susceptibles, infectados y removidos durante y después de la aplicación de las medidas de distanciamiento social a partir de los datos publicados por la Secretaría de Salud de México. RESULTADOS: Desde el inicio del brote hasta la suspensión de actividades escolares (28 de abril al 13 de mayo del 2009, la mediana nacional de R fue de 1,13. En el período posterior (14 de mayo al 17 de julio del 2009 la mediana nacional de R disminuyó a 1,01. CONCLUSIONES: Se demostró que se presentaron diversos escenarios de la epidemia a nivel nacional. Se sugiere tener en cuenta el comportamiento heterogéneo a nivel estatal para la toma de decisiones sobre la adopción de medidas para mitigar epidemias de influenza.OBJECTIVE: Apply a mathematical model to estimate the epidemic patterns of influenza A (H1N1 in Mexico during the stages of application and suspension of measures to mitigate the epidemic. METHODS: The effective reproductive number (R for each state of Mexico during and after the application of social distancing measures was estimated by the SIR model (susceptible, infected, and recovered individuals based on data published by the Ministry of Health of Mexico. RESULTS: From the beginning of the outbreak until suspension of school activities (28 April-13 May 2009, the national median of R was 1.13. In the following period (14 May-17 July 2009 the national median of R decreased to 1.01. CONCLUSIONS: It was demonstrated that several epidemic scenarios occurred at the national level. It is suggested that heterogeneous patterns at the state level be taken into account in decision-making on the adoption of measures to mitigate

  16. FluDetWeb: an interactive web-based system for the early detection of the onset of influenza epidemics

    OpenAIRE

    Conesa, David; López-Quílez, Antonio; Martínez-Beneito, Miguel Ángel; Miralles, María Teresa; Verdejo, Francisco

    2009-01-01

    Background The early identification of influenza outbreaks has became a priority in public health practice. A large variety of statistical algorithms for the automated monitoring of influenza surveillance have been proposed, but most of them require not only a lot of computational effort but also operation of sometimes not-so-friendly software. Results In this paper, we introduce FluDetWeb, an implementation of a prospective influenza surveillance methodology based on a client-server architec...

  17. Rapid semiautomated subtyping of influenza virus species during the 2009 swine origin influenza A H1N1 virus epidemic in Milwaukee, Wisconsin.

    Science.gov (United States)

    Bose, Michael E; Beck, Eric T; Ledeboer, Nate; Kehl, Sue C; Jurgens, Lisa A; Patitucci, Teresa; Witt, Lorraine; LaGue, Elizabeth; Darga, Patrick; He, Jie; Fan, Jiang; Kumar, Swati; Henrickson, Kelly J

    2009-09-01

    In the spring of 2009, a novel influenza A (H1N1) virus (swine origin influenza virus [S-OIV]) emerged and began causing a large outbreak of illness in Milwaukee, WI. Our group at the Midwest Respiratory Virus Program laboratory developed a semiautomated real-time multiplex reverse transcription-PCR assay (Seasonal), employing the NucliSENS easyMAG system (bioMérieux, Durham, NC) and a Raider thermocycler (HandyLab Inc., Ann Arbor, MI), that typed influenza A virus, influenza B virus, and respiratory syncytial virus (RSV) and subtyped influenza A virus into the currently circulating H1 and H3 subtypes, as well as a similar assay that identified H1 of S-OIV. The Seasonal and H1 S-OIV assays demonstrated analytical limits of detection of tissue culture infective doses/ml and 3 to 30 input copies, respectively. Testing of the analytical specificities revealed no cross-reactivity with 41 and 26 different common organisms and demonstrated outstanding reproducibility of results. Clinical testing showed 95% sensitivity for influenza A virus and influenza B virus and 95 and 97% specificity compared to tissue culture. Comparisons of results from other molecular tests showed levels of positive agreement with the Seasonal and H1 S-OIV assay results of 99 and 100% and levels of negative agreement of 98 and 100%. This study has demonstrated the use of a semiautomated system for sensitive, specific, and rapid detection of influenza A virus, influenza B virus, and RSV and subtyping of influenza A virus into human H1 and H3 and S-OIV strains. This assay/system performed well in clinical testing of regular seasonal influenza virus subtypes and was outstanding during the 2009 Milwaukee S-OIV infection outbreak. This recent outbreak of infection with a novel influenza A (H1N1) virus also demonstrates the importance of quickly distributing information on new agents and of having rapid influenza virus subtyping assays widely available for clinical and public health decisions. PMID

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

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    Philippe Barboza

    Full Text Available 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.

  19. Role of Preschool and Primary School Children in Epidemics of Influenza A in a Local Community in Japan during Two Consecutive Seasons with A(H3N2) as a Predominant Subtype.

    Science.gov (United States)

    Mimura, Satoshi; Kamigaki, Taro; Takahashi, Yoshihiro; Umenai, Takamichi; Kudou, Mataka; Oshitani, Hitoshi

    2015-01-01

    Enhanced influenza surveillance was implemented to analyze transmission dynamics particularly driving force of influenza transmission in a community during 2011/12 and 2012/13 seasons in Odate City, Japan. In these two consecutive seasons, influenza A(H3N2) was the predominant influenza A subtype. Suspected influenza cases were tested by commercial rapid test kits. Demographic and epidemiological information of influenza positive cases were recorded using a standardized questionnaire, which included age or age group, date of visit, date of fever onset, and the result of rapid test kit. Epidemiological parameters including epidemic midpoint (EM) and growth rate (GR) were analyzed. In 2012/13 season, numbers of influenza A positive cases were significantly lower among preschool (212 cases) and primary school (224 cases) children than in 2011/12 season (461 and 538 cases, respectively). Simultaneously, total influenza A cases were also reduced from 2,092 in 2011/12 season to 1,846 in 2012/13 season. The EMs in preschool and primary school children were earlier than EMs for adult and all age group in both 2011/12 and 2012/13 seasons. The GR in 2012/13 season was significantly lower than that in 2011/12 season (0.11 and 0.18, respectively, p = 0.003). Multiple linear regression analysis by school districts revealed that GRs in both seasons were significantly correlated with the incidence of school age children. Our findings suggest that preschool and primary school children played an important role as a driving force of epidemics in the community in both 2011/12 and 2012/13 seasons. The reduction of total influenza A cases in 2012/13 season can be explained by decreased susceptible population in these age groups due to immunity acquired by infections in 2011/12 season. Further investigations are needed to investigate the effect of pre-existing immunity on influenza transmission in the community. PMID:25942315

  20. 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. PMID:26443437

  1. Analysis of Etiology of Influenza during Influenza A (H1N1) Epidemic in Zhuhai City%甲型H1N1流感流行期间珠海市流感病原学分析

    Institute of Scientific and Technical Information of China (English)

    徐郁; 周勇; 周伴群; 焦亮; 谭爱军; 李德云

    2012-01-01

    was a linear positive relationship between the numbers of influenza cases and ILI cases. The multiple correlation coefficient was 0.64 (P<0.05). Conclusions Influenza epidemic intensity in Zhuhai City was higher than the average level in Guangdong province. Young people are the main population with influenza infection.

  2. Effects of closing and reopening live poultry markets on the epidemic of human infection with avian influenza A virus

    Science.gov (United States)

    Lu, Jian; Liu, Wendong; Xia, Rui; Dai, Qigang; Bao, Changjun; Tang, Fenyang; Zhu, yefei; Wang, Qiao

    2016-01-01

    Abstract Live poultry markets (LPMs) are crucial places for human infection of influenza A (H7N9 virus). In Yangtze River Delta, LPMs were closed after the outbreak of human infection with avian influenza A (H7N9) virus, and then reopened when no case was found. Our purpose was to quantify the effect of LPMs’ operations in this region on the transmission of influenza A (H7N9) virus. We obtained information about dates of symptom onset and locations for all human influenza A (H7N9) cases reported from Shanghai, Jiangsu and Zhejiang provinces by May 31, 2014, and acquired dates of closures and reopening of LPMs from official media. A two-phase Bayesian model was fitted by Markov Chain Monte Carlo methods to process the spatial and temporal influence of human cases. A total of 235 cases of influenza A (H7N9) were confirmed in Shanghai, Jiangsu and Zhejiang by May 31, 2014. Using these data, our analysis showed that, after LPM closures, the influenza A (H7N9) outbreak disappeared within two weeks in Shanghai, one week in Jiangsu, and one week in Zhejiang, respectively. Local authorities reopened LPMs when there was no outbreak of influenza A (H7N9), which did not lead to reemergence of human influenza A (H7N9). LPM closures were effective in controlling the H7N9 outbreak. Reopening of LPM in summer did not increase the risk of human infection with H7N9. Our findings showed that LPMs should be closed immediately in areas where the H7N9 virus is confirmed in LPM. When there is no outbreak of H7N9 virus, LPMs can be reopened to satisfy the Chinese traditional culture of buying live poultry. In the long term, local authorities should take a cautious attitude in permanent LPM closure.

  3. Trends in influenza vaccination coverage in Portugal from 1998 to 2010: effect of major pandemic threats

    OpenAIRE

    Sousa Pinto, Cátia; Nunes, Baltazar; BRANCO, Maria João; Marinho Falcão, José

    2013-01-01

    BACKGROUND: Vaccination is the key measure available for prevention of the public health burden of annual influenza epidemics. This article describes national trends in seasonal influenza vaccine (IV) coverage in Portugal from 1998/99 to 2010/11, analyzes progress towards meeting WHO 2010 coverage goals, and addresses the effect of major public health threats of the last 12 years (SARS in 2003/04, influenza A (H5N1) in 2005/06, and the influenza A (H1N1)2009 pandemic) on vaccination trends. ...

  4. Influenza

    OpenAIRE

    Forleo-Neto Eduardo; Halker Elisa; Santos Verônica Jorge; Paiva Terezinha Maria; Toniolo-Neto João

    2003-01-01

    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 mut...

  5. 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.

  6. 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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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.

  10. Pandemic influenza: certain uncertainties

    OpenAIRE

    Morens, David M.; Taubenberger, Jeffery K.

    2011-01-01

    For at least five centuries, major epidemics and pandemics of influenza have occurred unexpectedly and at irregular intervals. Despite the modern notion that pandemic influenza is a distinct phenomenon obeying such constant (if incompletely understood) rules such as dramatic genetic change, cyclicity, “wave” patterning, virus replacement, and predictable epidemic behavior, much evidence suggests the opposite. Although there is much that we know about pandemic influenza, there appears to be mu...

  11. Non-periodic outbreaks of recurrent epidemics and its network modelling

    Science.gov (United States)

    Zheng, Muhua; Wang, Chaoqing; Zhou, Jie; Zhao, Ming; Guan, Shuguang; Zou, Yong; Liu, Zonghua

    2015-11-01

    The study of recurrent epidemic outbreaks has been attracting great attention for decades, but its underlying mechanism is still under debate. Based on a large number of real data from different cities, we find that besides the seasonal periodic outbreaks of influenza, there are also non-periodic outbreaks, i.e. non-seasonal or non-annual behaviors. To understand how the non-periodicity shows up, we present a network model of SIRS epidemic with both time-dependent infection rate and a small possibility of persistent epidemic seeds, representing the influences from the larger annual variation of environment and the infection generated spontaneously in nature, respectively. Our numerical simulations reveal that the model can reproduce the non-periodic outbreaks of recurrent epidemics with the main features of real influenza data. Further, we find that the recurrent outbreaks of epidemic depend not only on the infection rate but also on the density of susceptible agents, indicating that they are both the necessary conditions for the recurrent epidemic patterns with non-periodicity. A theoretical analysis based on Markov dynamics is presented to explain the numerical results. This finding may be of significance to the control of recurrent epidemics.

  12. Economic Appraisal of Ontario's Universal Influenza Immunization Program: A Cost-Utility Analysis

    OpenAIRE

    Sander, Beate; Kwong, Jeffrey C.; Bauch, Chris T.; Maetzel, Andreas; McGeer, Allison; Raboud, Janet M.; Krahn, Murray

    2010-01-01

    Editors' Summary Background Annual outbreaks (epidemics) of influenza—a viral disease of the nose, throat, and airways—make millions of people ill and kill about 500,000 individuals every year. In doing so, they impose a considerable economic burden on society in terms of health care costs and lost productivity. Influenza epidemics occur because small but frequent changes in the viral proteins to which the immune system responds mean that an immune response produced one year by exposure to an...

  13. Transmission of influenza reflects seasonality of wild birds across the annual cycle.

    Science.gov (United States)

    Hill, Nichola J; Ma, Eric J; Meixell, Brandt W; Lindberg, Mark S; Boyce, Walter M; Runstadler, Jonathan A

    2016-08-01

    Influenza A Viruses (IAV) in nature must overcome shifting transmission barriers caused by the mobility of their primary host, migratory wild birds, that change throughout the annual cycle. Using a phylogenetic network of viral sequences from North American wild birds (2008-2011) we demonstrate a shift from intraspecific to interspecific transmission that along with reassortment, allows IAV to achieve viral flow across successive seasons from summer to winter. Our study supports amplification of IAV during summer breeding seeded by overwintering virus persisting locally and virus introduced from a wide range of latitudes. As birds migrate from breeding sites to lower latitudes, they become involved in transmission networks with greater connectivity to other bird species, with interspecies transmission of reassortant viruses peaking during the winter. We propose that switching transmission dynamics may be a critical strategy for pathogens that infect mobile hosts inhabiting regions with strong seasonality. PMID:27324078

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

    Science.gov (United States)

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

    2016-07-01

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

  15. 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.

    Science.gov (United States)

    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. PMID:25023603

  16. Twitter Improves Influenza Forecasting

    OpenAIRE

    Paul, Michael J.; Dredze, Mark; Broniatowski, David

    2014-01-01

    Accurate disease forecasts are imperative when preparing for influenza epidemic outbreaks; nevertheless, these forecasts are often limited by the time required to collect new, accurate data. In this paper, we show that data from the microblogging community Twitter significantly improves influenza forecasting. Most prior influenza forecast models are tested against historical influenza-like illness (ILI) data from the U.S. Centers for Disease Control and Prevention (CDC). These data are releas...

  17. On epidemic modeling in real time: An application to the 2009 Novel A (H1N1 influenza outbreak in Canada

    Directory of Open Access Journals (Sweden)

    Fisman David N

    2010-11-01

    Full Text Available Abstract Background Management of emerging infectious diseases such as the 2009 influenza pandemic A (H1N1 poses great challenges for real-time mathematical modeling of disease transmission due to limited information on disease natural history and epidemiology, stochastic variation in the course of epidemics, and changing case definitions and surveillance practices. Findings The Richards model and its variants are used to fit the cumulative epidemic curve for laboratory-confirmed pandemic H1N1 (pH1N1 infections in Canada, made available by the Public Health Agency of Canada (PHAC. The model is used to obtain estimates for turning points in the initial outbreak, the basic reproductive number (R0, and for expected final outbreak size in the absence of interventions. Confirmed case data were used to construct a best-fit 2-phase model with three turning points. R0 was estimated to be 1.30 (95% CI 1.12-1.47 for the first phase (April 1 to May 4 and 1.35 (95% CI 1.16-1.54 for the second phase (May 4 to June 19. Hospitalization data were also used to fit a 1-phase model with R0 = 1.35 (1.20-1.49 and a single turning point of June 11. Conclusions Application of the Richards model to Canadian pH1N1 data shows that detection of turning points is affected by the quality of data available at the time of data usage. Using a Richards model, robust estimates of R0 were obtained approximately one month after the initial outbreak in the case of 2009 A (H1N1 in Canada.

  18. Assessing the Role of Voluntary Self-Isolation in the Control of Pandemic Influenza Using a Household Epidemic Model

    Directory of Open Access Journals (Sweden)

    Qingxia Zhang

    2015-08-01

    Full Text Available In the absence of effective vaccines, antiviral drugs and personal protective measures, such as voluntary self-isolation, have been a part of preparedness plans for the next influenza pandemic. We used a household model to assess the effect of voluntary self-isolation on outbreak control when antiviral drugs are not provided sufficiently early. We found that the early initiation of voluntary self-isolation can overcome the negative effects caused by a delay in antiviral drug distribution when enough symptomatic individuals comply with home confinement at symptom onset. For example, for the baseline household reproduction number RH0 = 2:5, if delays of one or two days occur between clinical symptom development and the start of antiviral prophylaxis, then compliance rates of q ≥ 0:41 and q ≥ 0:6, respectively, are required to achieve the same level of effectiveness as starting antiviral prophylaxis at symptom onset. When the time to beginning voluntary self-isolation after symptom onset increases from zero to two days, this strategy has a limited effect on reducing the transmission of influenza; therefore, this strategy should be implemented as soon as possible. In addition, the effect of voluntary self-isolation decreases substantially with the proportion of asymptomatic infections increasing.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 甲型H1N1流感流行期间发热门诊的护理研究%Influenza A H1N1 Influenza During the Epidemic of Fever Clinic Nursing Research

    Institute of Scientific and Technical Information of China (English)

    孟广丽

    2014-01-01

    目的:探讨甲型H1N1流感流行期间发热门诊的护理管理。方法通过构建完全独立的发热门诊,制定完善的工作制度流程、并加强对医护人员的培训,实施规范化的管理,严格落实消毒隔离措施,并做好医护人员的防护。结果全部患者均主动愿意接受隔离,积极配合医院的工作,经治疗均有效治愈出院,无院内感染,无医护人员感染现象。结论在甲型H1N1流感流行期间采用相应的护理管理措施,能有效防控甲型H1N1流感的流行。%Objective To study the a/H1N1 flu epidemic during the fever outpatient nursing management. Methods By building a completely independent fever outpatient service, improve the system of work processes, and strengthen the training of medical staff, the implementation of standardized management, strict disinfection and isolation measures, the implementation of protection and medical staff. Results All patients were willing to accept the isolation actively, work actively cooperate with the hospital, after the treatment were cured and discharged, effectively without nosocomial infection, no medical staff infected phenomenon. Conclusion During the period of the a/H1N1 flu pandemic with the corresponding nursing measures, can effective prevention and control of influenza a H1N1 flu epidemic.

  1. Influenza Vaccination in Community Dwelling Elderly Persons

    NARCIS (Netherlands)

    A.C.G. Voordouw (Bettie)

    2005-01-01

    textabstractAn influenza epidemic was first described in 1173, although there are reports of influenza as early as 412 BC. Recurrent epidemics and incidental pandemics caused by influenza virus are documented since the last 400 years. These were based upon clinical observation and epidemiology. Alth

  2. Universal immunity to influenza must outwit immune evasion

    Directory of Open Access Journals (Sweden)

    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

  3. INFLUENZA SURVEILLANCE IN RUSSIA BASED ON EPIDEMIOLOGICAL AND LABORATORY DATA FOR THE PERIOD FROM 2005 TO 2012

    Directory of Open Access Journals (Sweden)

    Sominina Anna

    2013-01-01

    Full Text Available Exchange of information on and sharing of influenza viruses through the GISRS network has great significance for understanding influenza virus evolution, recognition of a new pandemic virus emergence and for preparing annual WHO recommendations on influenza vaccine strain composition. Influenza surveillance in Russia is based on collaboration of two NICs with 59 Regional Bases. Most epidemiological and laboratory data are entered through the internet into the electronic database at the Research Institute of Influenza (RII, where they are analyzed and then reported to the Ministry of Public Health of Russia. Simultaneously, data are introduced into WHO’s Flu Net and Euro Flu, both electronic databases. Annual influenza epidemics of moderate intensity were registered during four pre-pandemic seasons. Children aged 0-2 and 3-6 years were the most affected groups of the population. Influenza registered clinically among hospitalized patients with respiratory infections for the whole epidemic period varied between 1.3 and 5.4% and up but to 18.5-23.0% during the peak of the two pandemic waves caused by influenza A(H1N1 pdm 09 virus and to lesser extent (2.9 to 8.5% during usual seasonal epidemics. Most epidemics were associated with influenza A(H1N1, A(H3N2 and B co-circulation. During the two pandemic waves (in 2009-2010 and 2010-2011 influenza A(H1N1 pdm 09 predominated. It was accompanied by a rapid growth of influenza morbidity with a significant increase of both hospitalization and mortality. The new pandemic virus displaced the previous seasonal A(H1N1 virus completely. As a rule, most of the influenza viruses circulating in Russia were antigenic ally related to the strains recommended by WHO for vaccine composition for the Northern hemisphere with the exception of two seasons when an unexpected replacement of the influenza B Victoria lineage by Yamagata lineage (2007-2008 and the following return of Victoria lineage viruses (2008-2009 was

  4. Analysis of Epidemic of the influenza in Chongqing 2009%重庆市2009年流感监测结果分析

    Institute of Scientific and Technical Information of China (English)

    肖达勇; 戚小东; 凌华; 张敏; 冯燕; 赵婷; 陈爽; 孙军; 肖邦忠; 王豫林; 李勤; 龙江; 熊宇; 夏雨; 赵寒; 马颖; 易娟; 陈熙

    2012-01-01

    目的 分析重庆市2009年流感的流行特征,为制定防控策略提供科学依据.方法 对重庆市流感病例进行描述性流行病学分析;监测哨点医院门诊流感样病例就诊比、病毒谱和优势毒株;监测流感样病例、急性呼吸道感染病例聚集和暴发疫情流行特征、病毒谱和流行毒株.结果 2009年,重庆市报告甲型H1N1流感病例3178例,死亡2例,发病率为11.16/10万,死亡率为0.007/10万,病死率为0.06%;报告季节性流感11708例,无死亡,发病率为41.24/10万.甲型H1N1l流感为2009年流感流行的优势毒株,在重庆的流行过程经历了输入个案病例、输入聚集性病例、病例本土化并出现多点聚集3个阶段,流行高峰为10月.病例分布于全市40个区县,主城区发病率高于远郊县.男∶女=1.35∶1,报告发病以10~20岁组最多,职业以学生为主.2009年11月和2010年1月两次人群甲型H1N1流感病毒血清抗体监测阳性率分别为15.40%和10.14%.结论 2009年重庆市发生了流感流行,疫情已出现本土化;学校是流感发病的重点场所,学生是罹患的重点人群;发现的病例为冰山一角,估计目前重庆市的感染人群在300~400万,病例在200万左右.%OBJECTIVE To predict the morbidity tendency, and provide scientific evidence for its control told prevention in Chongqing according to the analysis of the epidemic situation of the A H1N1 flu in Chongqing from January to November in 2009. METHODS Using descriptive epidemiology analysis, we monitored the visit ratio, spectra and dominate strains of influenza virus among ILI (influenza-like illness) cases in OPC (out-patient clinic) of sentinel hospitals, and monitor the epidemic traits, spectra and dominate strains of influenza virus in ILI and ARI (acute respiratory infection) cases. RESULTS 3178 A H1N1 cases and 2 death cases were reported accumulatively in 2009. The IR (incidence rate) was 11.16/100 000, the mortality rate was 0

  5. 流感病毒Real-time RT-PCR核酸检测及流行情况分析%Detection of Influenza Viruses Using Real-time RT-PCR and Analysis of Influenza Epidemic Situation

    Institute of Scientific and Technical Information of China (English)

    冀林立

    2014-01-01

    Objective To analyze the results of detection on influenza virus in Ordos in 2012, in order to provide scientific basis for prevention and control of flu in this area. Methods Influenza throat swab specimens were col ected from sentinel hospital for virus nucleic acid detection by Real-time RT-PCR. Results:A total of 281 throat swab specimens were detected, 35 were positive for influenza virus nucleic acid, at a percentage of 12.46%. In which there was 16 cases of B type flu, at a percentage of 5.69%, 15 cases of seasonal H3, at a percentage of 5.34%,2 cases of new H1N1, at a percentage of 0.71%, 2 positive of A type undentified,at a percentage of 0.71%. The detection positive rate were 11.36%、27.50%、37.50%in January ,February and March, were 5.00%in October and December,no positive sample was detected in other month. Conclusion The survey showed that the major epidemic seasons were winter and spring,the major epidemic strains of the flu were B type and H3 type.%目的:分析鄂尔多斯市2012年流感检测结果,为本地区流感预防控制提供科学依据。方法采用Real-time RT-PCR法对哨点医院采集的流感样病例咽拭子标本进行病毒核酸检测。结果共检测流感咽拭子标本281份,流感病毒核酸阳性35份,总阳性率为12.46%。其中乙型16份,占5.69%,季节性H3亚型15份,占5.34%,甲型H1N12份,占0.71%,甲型未分型2份,占0.71%。2012年1月~3月阳性率分别为11.36%、27.50%、37.50%,10月和12月阳性率均为5.00%,其它月份未检出阳性。结论监测显示鄂尔多斯地区流感流行季节主要为冬春季,流行毒株主要是乙型和季节性H3亚型。

  6. Universal influenza vaccines: Shifting to better vaccines.

    Science.gov (United States)

    Berlanda Scorza, Francesco; Tsvetnitsky, Vadim; Donnelly, John J

    2016-06-01

    Influenza virus causes acute upper and lower respiratory infections and is the most likely, among known pathogens, to cause a large epidemic in humans. Influenza virus mutates rapidly, enabling it to evade natural and vaccine-induced immunity. Furthermore, influenza viruses can cross from animals to humans, generating novel, potentially pandemic strains. Currently available influenza vaccines induce a strain specific response and may be ineffective against new influenza viruses. The difficulty in predicting circulating strains has frequently resulted in mismatch between the annual vaccine and circulating viruses. Low-resource countries remain mostly unprotected against seasonal influenza and are particularly vulnerable to future pandemics, in part, because investments in vaccine manufacturing and stockpiling are concentrated in high-resource countries. Antibodies that target conserved sites in the hemagglutinin stalk have been isolated from humans and shown to confer protection in animal models, suggesting that broadly protective immunity may be possible. Several innovative influenza vaccine candidates are currently in preclinical or early clinical development. New technologies include adjuvants, synthetic peptides, virus-like particles (VLPs), DNA vectors, messenger RNA, viral vectors, and attenuated or inactivated influenza viruses. Other approaches target the conserved exposed epitope of the surface exposed membrane matrix protein M2e. Well-conserved influenza proteins, such as nucleoprotein and matrix protein, are mainly targeted for developing strong cross-protective T cell responses. With multiple vaccine candidates moving along the testing and development pipeline, the field is steadily moving toward a product that is more potent, durable, and broadly protective than previously licensed vaccines. PMID:27038130

  7. Swine Influenza Update

    Science.gov (United States)

    On April 24, 2009, the Centers for Disease Control (CDC) confirmed an influenza epidemic was occurring in people and the genetic lineage was most closely related to influenza viruses known to be circulating in swine. The outbreak epicenter appeared to be in central Mexico and the virus spread to th...

  8. Analysis of the epidemic characters of influenza in Yunnan Province from 2006-2010%云南省2006~2010年流感监测结果分析

    Institute of Scientific and Technical Information of China (English)

    罗春蕊; 赵群; 向以斌; 宁德明; 李娟; 蒋立; 徐闻

    2012-01-01

    OBJECTIVE To explore the epidemic characters of influenza in Yunnan Province from 2006-2010, and provide scientific basis for the prevention of influenza. METHODS The data of epidemiology and etiology of influenza-likeillness (III) and outbreaks of influenza in Yunnan Province in 2006-2010 were collected and analyzed. RESULTS By collecting the data of national influenza surveillance hospitals from 2006-2010, the average percentage of the number of ILI cases accounted for total outpatient was 3.56%, and the peaks of epidemic of influenza were from September to March in the next year. All the influenza surveillance hospitals in Yunnan Province collected 23 618 influenza specimens, and 785 influenza virus strains were obtained. The positive rate was 3.32%, and most of them were B subtype (288 strains, 36.69%). 2 394 nucleic acid positive specimens were obtained in 2009-2010, and positive rate was 14.57%. Most of them were A/H1N1 subtype (1 599 positive specimens, 66.80%). There were 139 outbreaks of influenza from 2006-2010 in Yunnan Province. All the outbreaks of influenza occurred in primary and middle schools. The peak of outbreaks of influenza was in March to April (63 outbreaks, 45.32%) and September (37 outbreaks, 26.62%). 3 952 influenza specimens were collected and 314 influenza virus strains were obtained, and with positive rate of 7.95%. Most of them were B type (229strains, 72.93%). 1 408 nucleic acid positive specimens were obtained from 2009-2010, and with the positive rate of 42.84%. Most of them were A/H1N1 subtype (869 positive specimens, 61.72%). CONCLUSION The peak of hospital surveillance and the peak of outbreaks of influenza was accordant. The peaks of epidemic of influenza in 2006-2010 were in Spring and Autumn. Different types of strain predominated alternatively, and the outbreaks of influenza were mainly occurred in primary and middle schools.%目的 探讨2006~2010年云南省流感的流行特征,为制定流感防制

  9. FluDetWeb: an interactive web-based system for the early detection of the onset of influenza epidemics

    OpenAIRE

    Miralles María; Martínez-Beneito Miguel; López-Quílez Antonio; Conesa David; Verdejo Francisco

    2009-01-01

    Abstract Background The early identification of influenza outbreaks has became a priority in public health practice. A large variety of statistical algorithms for the automated monitoring of influenza surveillance have been proposed, but most of them require not only a lot of computational effort but also operation of sometimes not-so-friendly software. Results In this paper, we introduce FluDetWeb, an implementation of a prospective influenza surveillance methodology based on a client-server...

  10. Influenza A virus infection in zebrafish recapitulates mammalian infection and sensitivity to anti-influenza drug treatment

    Directory of Open Access Journals (Sweden)

    Kristin A. Gabor

    2014-11-01

    Full Text Available Seasonal influenza virus infections cause annual epidemics and sporadic pandemics. These present a global health concern, resulting in substantial morbidity, mortality and economic burdens. Prevention and treatment of influenza illness is difficult due to the high mutation rate of the virus, the emergence of new virus strains and increasing antiviral resistance. Animal models of influenza infection are crucial to our gaining a better understanding of the pathogenesis of and host response to influenza infection, and for screening antiviral compounds. However, the current animal models used for influenza research are not amenable to visualization of host-pathogen interactions or high-throughput drug screening. The zebrafish is widely recognized as a valuable model system for infectious disease research and therapeutic drug testing. Here, we describe a zebrafish model for human influenza A virus (IAV infection and show that zebrafish embryos are susceptible to challenge with both influenza A strains APR8 and X-31 (Aichi. Influenza-infected zebrafish show an increase in viral burden and mortality over time. The expression of innate antiviral genes, the gross pathology and the histopathology in infected zebrafish recapitulate clinical symptoms of influenza infections in humans. This is the first time that zebrafish embryos have been infected with a fluorescent IAV in order to visualize infection in a live vertebrate host, revealing a pattern of vascular endothelial infection. Treatment of infected zebrafish with a known anti-influenza compound, Zanamivir, reduced mortality and the expression of a fluorescent viral gene product, demonstrating the validity of this model to screen for potential antiviral drugs. The zebrafish model system has provided invaluable insights into host-pathogen interactions for a range of infectious diseases. Here, we demonstrate a novel use of this species for IAV research. This model has great potential to advance our

  11. Influenza A virus infection in zebrafish recapitulates mammalian infection and sensitivity to anti-influenza drug treatment.

    Science.gov (United States)

    Gabor, Kristin A; Goody, Michelle F; Mowel, Walter K; Breitbach, Meghan E; Gratacap, Remi L; Witten, P Eckhard; Kim, Carol H

    2014-11-01

    Seasonal influenza virus infections cause annual epidemics and sporadic pandemics. These present a global health concern, resulting in substantial morbidity, mortality and economic burdens. Prevention and treatment of influenza illness is difficult due to the high mutation rate of the virus, the emergence of new virus strains and increasing antiviral resistance. Animal models of influenza infection are crucial to our gaining a better understanding of the pathogenesis of and host response to influenza infection, and for screening antiviral compounds. However, the current animal models used for influenza research are not amenable to visualization of host-pathogen interactions or high-throughput drug screening. The zebrafish is widely recognized as a valuable model system for infectious disease research and therapeutic drug testing. Here, we describe a zebrafish model for human influenza A virus (IAV) infection and show that zebrafish embryos are susceptible to challenge with both influenza A strains APR8 and X-31 (Aichi). Influenza-infected zebrafish show an increase in viral burden and mortality over time. The expression of innate antiviral genes, the gross pathology and the histopathology in infected zebrafish recapitulate clinical symptoms of influenza infections in humans. This is the first time that zebrafish embryos have been infected with a fluorescent IAV in order to visualize infection in a live vertebrate host, revealing a pattern of vascular endothelial infection. Treatment of infected zebrafish with a known anti-influenza compound, Zanamivir, reduced mortality and the expression of a fluorescent viral gene product, demonstrating the validity of this model to screen for potential antiviral drugs. The zebrafish model system has provided invaluable insights into host-pathogen interactions for a range of infectious diseases. Here, we demonstrate a novel use of this species for IAV research. This model has great potential to advance our understanding of

  12. 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.

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

    International Nuclear Information System (INIS)

    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

  14. 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.

  15. Heterosubtypic T-Cell Immunity to Influenza in Humans: Challenges for Universal T-Cell Influenza Vaccines

    Science.gov (United States)

    Sridhar, Saranya

    2016-01-01

    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 twenty-first century underlined the urgent need to develop new vaccines capable of protecting 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 recognizing conserved antigens are a key contributor in 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. PMID:27242800

  16. Novel hemagglutinin-based influenza virus inhibitors

    OpenAIRE

    Shen, Xintian; Zhang, Xuanxuan; Liu, Shuwen

    2013-01-01

    Influenza virus has caused seasonal epidemics and worldwide pandemics, which caused tremendous loss of human lives and socioeconomics. Nowadays, only two classes of anti-influenza drugs, M2 ion channel inhibitors and neuraminidase inhibitors respectively, are used for prophylaxis and treatment of influenza virus infection. Unfortunately, influenza virus strains resistant to one or all of those drugs emerge frequently. Hemagglutinin (HA), the glycoprotein in influenza virus envelope, plays a c...

  17. 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.

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

    Institute of Scientific and Technical Information of China (English)

    周祖木; 蔡圆圆; 魏晶娇; 陈晟; 潘琼娇; 马洪波

    2011-01-01

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

  19. 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.

  20. Ten influenza seasons in France: distribution and timing of influenza A and B circulation, 2003–2013

    OpenAIRE

    Mosnier, Anne; Caini, Saverio; Daviaud, Isabelle; Bensoussan, Jean-Louis; Stoll-Keller, Françoise; Bui, Tan Tai; Lina, Bruno; van der Werf, Sylvie; Cohen, Jean Marie; ,

    2015-01-01

    Background Describing the circulation of influenza viruses and the characteristics of seasonal epidemics remains an essential tool to optimize the strategies of influenza prevention and control. Special attention has been recently paid to influenza B in the context of the availability of a quadrivalent vaccine, containing two influenza B strains. Methods We used data from a practitioners-based influenza surveillance network to describe the circulation of influenza viruses in France from 2003–...

  1. 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

  2. Influenza update 2007-2008: vaccine advances, pandemic preparation.

    Science.gov (United States)

    Mossad, Sherif B

    2007-12-01

    Influenza vaccination remains our best measure to prevent epidemic and pandemic influenza. We must continue to improve vaccination rates for targeted populations. Antiviral options are currently limited to the neuraminidase inhibitors. PMID:18183839

  3. Pratiques sociales, politiques de santé publique et nouvelles épidémies en Egypte Social Behavior, Public Health Policies and New Epidemics in Egypt : The Case of Hepatitis C and Avian Influenza

    Directory of Open Access Journals (Sweden)

    Saadia Radi

    2011-04-01

    Full Text Available À partir de l’épidémie d’hépatite C et de la grippe aviaire en Égypte, cet article montre que les références culturelles sont moins importantes pour comprendre les systèmes de santé que les conditions sociales et économiques. Il insiste sur la nécessité d’étudier les contextes, en évitant l’erreur d’une approche culturaliste, même si les malades usent de thérapies « traditionnelles ». De ce point de vue, les politiques publiques sont plus importantes que les croyances. Le social est décrit comme le contexte écologique de l’épidémie, à travers l’exemple de l’hépatite C en Égypte.Using the epidemic of Hepatitis C and Avian influenza in Egypt as a case study, the paper discusses the approaches of the care health systems in social sciences. It shows that cultural skills are less important than social and economic factors. It argues that it is necessary to analyze the contexts and to avoid the fallacy of culturalism, even if sick persons use traditional cures. From this point of view, public policies are more important than beliefs. The social sphere is described as the ecological context of epidemic.

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

    OpenAIRE

    Vemula, Sai Vikram; Zhao, Jiangqin; Liu, Jikun; Wang, Xue; Biswas, Santanu; Hewlett, Indira

    2016-01-01

    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 pandemi...

  5. Clinical outcomes of seasonal influenza and pandemic influenza A (H1N1 in pediatric inpatients

    Directory of Open Access Journals (Sweden)

    Budd Alicia

    2010-10-01

    infection control efforts. We believe that this attention should become an annual effort for SI. Strong unified messages from health care providers and the media encouraging influenza vaccination will likely prove very useful in averting some of the morbidity related to influenza for future epidemics.

  6. Selecting nonpharmaceutical interventions for influenza

    OpenAIRE

    Jones, RM; Adida, E

    2013-01-01

    Models of influenza transmission have focused on the ability of vaccination, antiviral therapy, and social distancing strategies to mitigate epidemics. Influenza transmission, however, may also be interrupted by hygiene interventions such as frequent hand washing and wearing masks or respirators. We apply a model of influenza disease transmission that incorporates hygiene and social distancing interventions. The model describes population mixing as a Poisson process, and the probability of in...

  7. The role of weather on the relation between influenza and influenza-like illness.

    Science.gov (United States)

    van Noort, Sander P; Águas, Ricardo; Ballesteros, Sébastien; Gomes, M Gabriela M

    2012-04-01

    Influenza epidemics, enabled by viral antigenic drift, occur invariably each winter in temperate climates. However, attempts to correlate the magnitude of virus change and epidemic size have been unsatisfactory. The incidence of influenza is not typically measured directly, but rather derived from the incidence of influenza-like illness (ILI), a clinical syndrome. Weather factors have been shown to influence the manifestation of influenza-like symptoms. We fitted an influenza transmission model to time series of influenza-like illness as monitored from 2003 to 2010 by two independent symptomatic surveillance systems (Influenzanet and EISN) in three European countries. By assuming that seasonality only acts upon the manifestation of symptoms, the model shows a significant correlation between the absolute humidity and temperature at the time of infection, and the proportion of influenza infections fulfilling the clinical ILI case definition, the so-called ILI factor. When a weather-dependent ILI factor is included in the model, the epidemic size of influenza-like illness becomes dependent not only on the susceptibility of the population at the beginning of the epidemic season but also on the weather conditions during which the epidemic unfolds. The combination reduces season-to-season variation in epidemic size and, interestingly, leads to a non-monotonic trend whereby the largest ILI epidemic occurs for moderate initial susceptibility. PMID:22214751

  8. Influenza A Virus and Influenza B Virus Can Induce Apoptosis via Intrinsic or Extrinsic Pathways and Also via NF-κB in a Time and Dose Dependent Manner

    OpenAIRE

    Ibrahim El-Sayed; Khalid Bassiouny; Aziz Nokaly; Abdelghani, Ahmed S.; Wael Roshdy

    2016-01-01

    Influenza viruses are able to cause annual epidemics and pandemics due to their mutation rates and reassortment capabilities leading to antigenic shifts and drifts. To identify host response to influenza A and B viruses on A549 and MDCK II cells at low and high MOIs, expressions of MxA and caspases 3, 8, and 9 and BAD, TNFα, and IκBα genes were measured in the cells supernatants. H1N1 and H3N2 prefer to initially enhance the intrinsic pathway, determined by higher caspase 9 activity in MDCK I...

  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. 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

  11. Genetic Strategy to Prevent Influenza Virus Infections in Animals

    OpenAIRE

    Chen, Jianzhu; Chen, Steve C.-Y.; Stern, Patrick; Scott, Benjamin B; Lois, Carlos

    2008-01-01

    The natural reservoirs of influenza viruses are aquatic birds. After adaptation, avian viruses can acquire the ability to infect humans and cause severe disease. Because domestic poultry serves as a key link between the natural reservoir of influenza viruses and epidemics and pandemics in human populations, an effective measure to control influenza would be to eliminate or reduce influenza virus infection in domestic poultry. The development and distribution of influenza-resistant poultry rep...

  12. 甲流期间医护人员的认知、心理状态回顾性分析%Retrospective Analysis on Cognition for Influenza A and Psychological Status of Medical Staffs during the Epidemic of Influenza A (H1N1)

    Institute of Scientific and Technical Information of China (English)

    武涧松; 闫涛; 彭石林

    2011-01-01

    目的 回顾性分析甲流期间高危医护人员对甲流的认知及心理状态,探讨其影响因素.方法 采用自制调查问卷,动态观察143名抗甲流医护人员甲流认知和心理状态,并以普通病房41名医护人员为对照,Logistic回归分析相关因素.结果 高危组甲流认知评分显著高于对照组(P<0.05).认知随疫情发展呈持续改善趋势,受培训次数、高危程度、职业、年龄、子女情况5个因素影响(OR>1).高危组心理异常重于对照(P<0.05),发热门诊最明显,主要表现为情绪和睡眠障碍,与认知水平、性别负相关(OR<1),与高危程度、疫情发展正相关(OR>1).结论 高危医护人员具有较高甲流认知水平,存在一定程度心理障碍,需要根据疫情变化和人员特征,给予针对性培训和心理干预.%Objective To analyze retrospectively cognition for Influenza A(H1N1) and psychological status of medical staffs in high-risk during Influenza A, and explore their affecting factors. Methods With self-designed questionnaire .cognition for Influenza A and psychological status of 143 medical staffs fighting against Influenza A were investigated dynamically,and compared with 41 medical staffs of general ward. Logistic regression was used to analyse their affecting factors. Results Cognition scores of high-risk groups were higher than those of control significantly (Pl). There were more serious psychological abnormalities in high-risk groups than control(P1). Conclusion Medical staffs in high-risk showed a higher level of cognition for Influenza A and a certain degree of psychological abnormalities at the same time. It was necessary to give medical staffs pointed training and psychological Intervention according to changes of the epidemic and characteristics of personnel.

  13. Clinical data on Fluarix: an inactivated split seasonal influenza vaccine.

    Science.gov (United States)

    El Sahly, Hana M; Keitel, Wendy A

    2008-08-01

    Influenza viruses cause annual winter epidemics in temperate regions, with significant morbidity, mortality and economical impact. Fluarix is a split, trivalent, inactivated vaccine, manufactured from highly purified, egg-grown influenza viruses by GlaxoSmithKline. In 2005, Fluarix underwent accelerated approval for use in adults by the US FDA following a US-based, randomized, placebo-controlled trial that established its safety and immunogenicity in adults. The vaccine has been licensed in Europe since 1992 for all age groups. Multiple registration trials in all age groups in Europe have demonstrated that the vaccine was safe and well tolerated and of immunogenicity standards that met the requirements of the European Committee for Medicinal Products for Human Use. There are no published clinical trials evaluating the effectiveness or efficacy of Fluarix against influenza and its complications. Currently, Fluarix plays an important role in the diversification of the supply chain of influenza vaccine to the community. However, vaccines with improved immunogenicity in at-risk populations, such as the elderly, and with less reliance on growth in eggs, as well as the inherent demanding timelines, are needed to enhance the control of influenza. PMID:18665769

  14. Influenza in het seizoen 1993-94; vaccinsamenstelling voor het seizoen 1994-95.

    NARCIS (Netherlands)

    E.C.J. Claas (Eric); J.C. de Jong (Jan); A.I.M. Bartelds (Aad); J.K. van Wijngaarden; N. Masurel (Nic); A.D.M.E. Osterhaus (Albert)

    1994-01-01

    textabstractThe influenza season 1993/'94 in the Netherlands and the rest of Northwestern Europe was marked by an influenza A/H3N2 epidemic. The morbidity of this epidemic was moderate, but a high mortality rate was observed. The epidemic viruses, represented by A/Netherlands/241/93 (H3N2), were cha

  15. 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

  16. 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

  17. 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.

  18. 流感病毒的变异及其引发流行的预防%The prevention of the epidemic of influenza caused by varied influenza virus

    Institute of Scientific and Technical Information of China (English)

    卢亦愚

    2005-01-01

    流行性感冒(influenza)简称流感,是由流感病毒(influenza virus)引起的急性呼吸道传染病.该病传染性强,传播快,常发生爆发、流行或世界性大流行,是迄今尚未能达到有效控制的世界性传染病,对人类健康,甚至对社会稳定产生重大影响,危害极大.

  19. 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

  20. The evolutionary emergence of pandemic influenza

    OpenAIRE

    Day, Troy; André, Jean-Baptiste; Park, Andrew

    2006-01-01

    Pandemic influenza remains a serious public health threat and the processes involved in the evolutionary emergence of pandemic influenza strains remain incompletely understood. Here, we develop a stochastic model for the evolutionary emergence of pandemic influenza, and use it to address three main questions. (i) What is the minimum annual number of avian influenza virus infections required in humans to explain the historical rate of pandemic emergence? (ii) Are such avian influenza infection...

  1. Influenza and bacterial pneumonia - constant companions

    OpenAIRE

    Wunderink, Richard G.

    2010-01-01

    Sequential or concomitant influenza and bacterial pneumonia are two common syndromes seen in community-acquired pneumonia. Inadequacies of diagnostic testing make separating simple pneumonia with either bacteria or influenza from concomitant or sequential influenza with both microorganisms difficult, although the novel 2009 H1N1 epidemic may improve the availability of molecular testing for viruses. Given the frequency of viral pneumonia and diagnostic limitations, empirical antivirals may be...

  2. Investigation of influenza in migrating birds, the primordial reservoir and transmitters of influenza in Brazil Investigação de influenza em aves migratórias, principal reservatório e transporte de influenza no Brasil

    Directory of Open Access Journals (Sweden)

    Adélia Hiroko Nagamori Kawamoto

    2005-03-01

    Full Text Available Birds are the most important reservoirs of the influenza virus. Its maintenance in its natural hosts, including man, allows the influenza virus to reassorts its strains. The recent report of an avian influenza A (H5N1 virus in humans, was in a child with fatal respiratory illness in China, 1997. The current study was conducted to elucidate the transportation of the influenza by birds that migrate, annually, through the both Northern and Southern hemispheres, with special attention paid to the Vireo olivaceus [Juruviara(BR or Red-eyed vireo(USA] species, which travels from the USA to Brazil, and vice versa, and the Elaenia mesoleuca [Tuque(BR or (USA] species that flies over the entire Southern Hemisphere. There are two species of birds, which breed and migrate in São Paulo State, Brazil, and which were demonstrated to carry Influenza virus, were selected. The viral particles isolated were observed by electron microscopy. The influenza virus was detected by the House Duplex/PCR and Gloria molecular biology tests. The results demonstrated that the Elaenia mesoleuca and Vireo olivaceus bird species are carrying the Influenza virus whilst crossing both the Northern and Southern hemispheres. To understand the role that these migrating birds may play in epidemic influenza, in Brazil, characterization of avian influenza subtypes will be done.Os mais importantes reservatórios do vírus influenza são os pássaros. A manutenção do vírus influenza em hospedeiros naturais, inclusive o homem, permite que esse vírus realize rearranjos entre as suas cepas. O recente relato de uma cepa influenza aviária A(H5N1, em humanos, se deu em uma criança com doença respiratória fatal, na China em 1977. O presente estudo foi conduzido para elucidar o transporte da influenza por pássaros que migram, anualmente, através de ambos hemisférios o do Norte e do Sul, com especial atenção voltada à espécies Vireo olivaceo [Juruviara(BR e Red-eyed vireo(USA] que

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

    Science.gov (United States)

    Elbers, Armin R W; Koch, Guus; Bouma, Annemarie

    2005-06-01

    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 infected and 297 non-infected) with a clinical suspicion of an infection with HPAI virus were investigated with respect to the clinical signs observed. Standardized reports were analysed with respect to observed clinical signs in the flocks. Various poultry types were distinguished. In infected commercial flocks with egg-producing chickens, the presence of increased mortality, apathy, coughing, reduction in normal vocalization, or pale eggs appeared to be overall the most sensitive indicators to detect a HPAI outbreak, matching a sensitivity of 99% with a specificity of 23%. In infected turkey flocks, the presence of apathy, decreased growth performance, reduction of normal vocalization, swollen sinuses, yawning, huddling, mucosal production from the beak, or lying down with an extended neck appeared to be overall the most sensitive indicators to detect a HPAI outbreak, matching a sensitivity of 100% with a specificity of 79%. In infected backyard/hobby flocks, increased mortality or swollen head appeared to be overall the most sensitive indicators of a HPAI outbreak, matching a sensitivity of 100% with a specificity of 26%. These results indicate that there is a solid basis for the choice of using increased mortality in the operational SRS in The Netherlands as an early warning system for HPAI outbreaks. The presence of apathy, specifically for turkeys, should be added to the SRS as an indicator. PMID:16191700

  4. Induction of a Protective Heterosubtypic Immune Response Against the Influenza Virus by using Recombinant Adenoviral Vectors Expressing Hemagglutinin of the Influenza H5 Virus.

    Science.gov (United States)

    Shmarov, M M; Sedova, E S; Verkhovskaya, L V; Rudneva, I A; Bogacheva, E A; Barykova, Yu A; Shcherbinin, D N; Lysenko, A A; Tutykhina, I L; Logunov, D Y; Smirnov, Yu A; Naroditsky, B S; Gintsburg, A L

    2010-04-01

    Influenza viruses are characterized by a high degree of antigenic variability, which causes the annual emergence of flu epidemics and irregularly timed pandemics caused by viruses with new antigenic and biological traits. Novel approaches to vaccination can help circumvent this problem. One of these new methods incorporates genetic vaccines based on adenoviral vectors. Recombinant adenoviral vectors which contain hemagglutinin-encoding genes from avian H5N1 and H5N2 (Ad-HA5-1 and Ad-HA5-2) influenza viruses were obtained using the AdEasy Adenoviral Vector System (Stratagene). Laboratory mice received a double intranasal vaccination with Ad-HA5-1 and Ad-HA5-2. This study demonstrates that immunization with recombinant adenoviruses bearing the Н 5 influenza virus hemagglutinin gene induces a immune response which protects immunized mice from a lethal dose of the H5 influenza virus. Moreover, it also protects the host from a lethal dose of the H1 virus, which belongs to the same clade as H5, but does not confer protection from the subtype H3 influenza virus, which belongs to a different clade. PMID:22649637

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

    OpenAIRE

    S Caini; Andrade, W; S Badur; Balmaseda, A.; A. Barakat; A Bella; Bimohuen, A.; Brammer, L; J Bresee; Bruno, A; Castillo, L.; Ciblak, M.A.; Clara, A.W.; C Cohen; Cutter, J

    2016-01-01

    Introduction 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. Methods 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 rep...

  6. Temporal patterns of influenza A and B in tropical and temperate countries: what are the lessons for influenza vaccination?

    OpenAIRE

    Saverio Caini; Winston Andrade; Selim Badur; Angel Balmaseda; Amal Barakat; Antonino Bella; Abderrahman Bimohuen; Lynnette Brammer; Joseph Bresee; Alfredo Bruno; Leticia Castillo; Ciblak, Meral A.; Alexey W Clara; Cheryl Cohen; Jeffery Cutter

    2016-01-01

    Introduction 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. Methods 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 rep...

  7. 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

  8. Mucosal immunization with recombinant adenovirus encoding soluble globular head of hemagglutinin protects mice against lethal influenza virus infection.

    Science.gov (United States)

    Kim, Joo Young; Choi, Youngjoo; Nguyen, Huan H; Song, Man Ki; Chang, Jun

    2013-12-01

    Influenza virus is one of the major sources of respiratory tract infection. Due to antigenic drift in surface glycoproteins the virus causes annual epidemics with severe morbidity and mortality. Although hemagglutinin (HA) is one of the highly variable surface glycoproteins of the influenza virus, it remains the most attractive target for vaccine development against seasonal influenza infection because antibodies generated against HA provide virus neutralization and subsequent protection against the virus infection. Combination of recombinant adenovirus (rAd) vector-based vaccine and mucosal administration is a promising regimen for safe and effective vaccination against influenza. In this study, we constructed rAd encoding the globular head region of HA from A/Puerto Rico/8/34 virus as vaccine candidate. The rAd vaccine was engineered to express high level of the protein in secreted form. Intranasal or sublingual immunization of mice with the rAd-based vaccine candidates induced significant levels of sustained HA-specific mucosal IgA and IgG. When challenged with lethal dose of homologous virus, the vaccinated mice were completely protected from the infection. The results demonstrate that intranasal or sublingual vaccination with HA-encoding rAd elicits protective immunity against infection with homologous influenza virus. This finding underlines the potential of our recombinant adenovirus-based influenza vaccine candidate for both efficacy and rapid production. PMID:24385946

  9. siRNA for Influenza Therapy

    OpenAIRE

    Sailen Barik

    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, trigg...

  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 Photos

    Science.gov (United States)

    ... Polio Whooping cough Influenza (flu) Rabies Yellow fever Influenza Photos Photographs accompanied by text that reads "Courtesy ... of these photos are quite graphic. Shows how influenza germs spread through the air when someone coughs ...

  12. On the epidemiology of influenza

    Directory of Open Access Journals (Sweden)

    Scragg Robert

    2008-02-01

    Full Text Available Abstract The epidemiology of influenza swarms with incongruities, incongruities exhaustively detailed by the late British epidemiologist, Edgar Hope-Simpson. He was the first to propose a parsimonious theory explaining why influenza is, as Gregg said, "seemingly unmindful of traditional infectious disease behavioral patterns." Recent discoveries indicate vitamin D upregulates the endogenous antibiotics of innate immunity and suggest that the incongruities explored by Hope-Simpson may be secondary to the epidemiology of vitamin D deficiency. We identify – and attempt to explain – nine influenza conundrums: (1 Why is influenza both seasonal and ubiquitous and where is the virus between epidemics? (2 Why are the epidemics so explosive? (3 Why do they end so abruptly? (4 What explains the frequent coincidental timing of epidemics in countries of similar latitude? (5 Why is the serial interval obscure? (6 Why is the secondary attack rate so low? (7 Why did epidemics in previous ages spread so rapidly, despite the lack of modern transport? (8 Why does experimental inoculation of seronegative humans fail to cause illness in all the volunteers? (9 Why has influenza mortality of the aged not declined as their vaccination rates increased? We review recent discoveries about vitamin D's effects on innate immunity, human studies attempting sick-to-well transmission, naturalistic reports of human transmission, studies of serial interval, secondary attack rates, and relevant animal studies. We hypothesize that two factors explain the nine conundrums: vitamin D's seasonal and population effects on innate immunity, and the presence of a subpopulation of "good infectors." If true, our revision of Edgar Hope-Simpson's theory has profound implications for the prevention of influenza.

  13. 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.

  14. Personal protective behaviour during an epidemic

    OpenAIRE

    Badham, Jennifer; Gilbert, Nigel

    2014-01-01

    The TELL ME simulation model is being developed to assist health authorities to understand the effects of their choices about how to communicate with citizens about protecting themselves from influenza epidemics. It will include an agent based model to simulate personal decisions to seek vaccination or adopt behaviour such as improved hand hygiene. This paper focusses on the design of the agents’ decisions, using a combination of personal attitude, average local attitude, the local number of ...

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

    OpenAIRE

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

    2011-01-01

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

  16. Effectiveness of influenza vaccination for preventing influenza-related complications in people with asthma:A systematic review protocol

    OpenAIRE

    Vasileiou, Eleftheria; Sheikh, Aziz; Butler, Chris; von Wissmann, Beatrix; McMenamin, Jim; Ritchie, Lewis; Tian, Lilly; Simpson, Colin

    2016-01-01

    Introduction: Influenza vaccination is administered annually as a preventive measure against influenza infection and influenza-related complications in highrisk individuals, such as those with asthma. However, the effectiveness of influenza vaccination in people with asthma against influenza-related complications is still not well established. Methods and analysis: We will search the following databases: MEDLINE (Ovid), EMBASE (Ovid), Cumulative Index to Nursing and Allied Health Literature (...

  17. Effectiveness of influenza vaccination for preventing influenza-related complications in people with asthma: a systematic review protocol

    OpenAIRE

    Vasileiou, Eleftheria; Sheikh, Aziz; Butler, Chris; von Wissmann, Beatrix; McMenamin, Jim; Ritchie, Lewis; Tian, Lilly; Simpson, Colin

    2016-01-01

    Introduction Influenza vaccination is administered annually as a preventive measure against influenza infection and influenza-related complications in high-risk individuals, such as those with asthma. However, the effectiveness of influenza vaccination in people with asthma against influenza-related complications is still not well established. Methods and analysis We will search the following databases: MEDLINE (Ovid), EMBASE (Ovid), Cumulative Index to Nursing and Allied Health Literature (C...

  18. Do recommended high-risk adults benefit from a first influenza vaccination?

    NARCIS (Netherlands)

    Hak, E; Buskens, E; Nichol, K L; Verheij, T J M

    2006-01-01

    It is unknown whether a first influenza vaccination protects high-risk adults from severe morbidity and mortality during influenza epidemics. As part of the PRISMA nested case-control study, we aimed to evaluate the effectiveness of first-time and repeat influenza vaccinations in adult persons recom

  19. 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....

  20. 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

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

    Science.gov (United States)

    Vemula, Sai Vikram; Zhao, Jiangqin; Liu, Jikun; Wang, Xue; Biswas, Santanu; Hewlett, Indira

    2016-01-01

    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. PMID:27077877

  2. Multi-spectral fluorescent reporter influenza viruses (Color-flu) as powerful tools for in vivo studies.

    Science.gov (United States)

    Fukuyama, Satoshi; Katsura, Hiroaki; Zhao, Dongming; Ozawa, Makoto; Ando, Tomomi; Shoemaker, Jason E; Ishikawa, Izumi; Yamada, Shinya; Neumann, Gabriele; Watanabe, Shinji; Kitano, Hiroaki; Kawaoka, Yoshihiro

    2015-01-01

    Seasonal influenza A viruses cause annual epidemics of respiratory disease; highly pathogenic avian H5N1 and the recently emerged H7N9 viruses cause severe infections in humans, often with fatal outcomes. Although numerous studies have addressed the pathogenicity of influenza viruses, influenza pathogenesis remains incompletely understood. Here we generate influenza viruses expressing fluorescent proteins of different colours ('Color-flu' viruses) to facilitate the study of viral infection in in vivo models. On adaptation to mice, stable expression of the fluorescent proteins in infected animals allows their detection by different types of microscopy and by flow cytometry. We use this system to analyse the progression of viral spread in mouse lungs, for live imaging of virus-infected cells, and for differential gene expression studies in virus antigen-positive and virus antigen-negative live cells in the lungs of Color-flu-infected mice. Collectively, Color-flu viruses are powerful tools to analyse virus infections at the cellular level in vivo to better understand influenza pathogenesis. PMID:25807527

  3. Characterization of Influenza Vaccine Hemagglutinin Complexes by Cryo-Electron Microscopy and Image Analyses Reveals Structural Polymorphisms

    Science.gov (United States)

    McCraw, Dustin M.; Gallagher, John R.

    2016-01-01

    Influenza virus afflicts millions of people worldwide on an annual basis. There is an ever-present risk that animal viruses will cross the species barrier to cause epidemics and pandemics resulting in great morbidity and mortality. Zoonosis outbreaks, such as the H7N9 outbreak, underscore the need to better understand the molecular organization of viral immunogens, such as recombinant influenza virus hemagglutinin (HA) proteins, used in influenza virus subunit vaccines in order to optimize vaccine efficacy. Here, using cryo-electron microscopy and image analysis, we show that recombinant H7 HA in vaccines formed macromolecular complexes consisting of variable numbers of HA subunits (range, 6 to 8). In addition, HA complexes were distributed across at least four distinct structural classes (polymorphisms). Three-dimensional (3D) reconstruction and molecular modeling indicated that HA was in the prefusion state and suggested that the oligomerization and the structural polymorphisms observed were due to hydrophobic interactions involving the transmembrane regions. These experiments suggest that characterization of the molecular structures of influenza virus HA complexes used in subunit vaccines will lead to better understanding of the differences in vaccine efficacy and to the optimization of subunit vaccines to prevent influenza virus infection. PMID:27074939

  4. Avian influenza: The tip of the iceberg

    OpenAIRE

    Balkhy Hanan

    2008-01-01

    For some years now, we have been living with the fear of an impending pandemic of avian influenza (AI). Despite the recognition, in 1996, of the global threat posed by the highly pathogenic H5N1 influenza virus found in farmed geese in Guangdong Province, China, planning for the anticipated epidemic remains woefully inadequate; this is especially true in developing countries such as Saudi Arabia. These deficiencies became obvious in 1997, with the outbreak of AI in the live animal markets in...

  5. Influenza A Virus Entry Inhibitors Targeting the Hemagglutinin

    OpenAIRE

    Shuwen Liu; Jie Yang; Xintian Shen; Minmin Li

    2013-01-01

    Influenza A virus (IAV) has caused seasonal influenza epidemics and influenza pandemics, which resulted in serious threat to public health and socioeconomic impacts. Until now, only 5 drugs belong to two categories are used for prophylaxis and treatment of IAV infection. Hemagglutinin (HA), the envelope glycoprotein of IAV, plays a critical role in viral binding, fusion and entry. Therefore, HA is an attractive target for developing anti‑IAV drugs to block the entry step of IAV infection. Her...

  6. Epidemic Percolation Networks, Epidemic Outcomes, and Interventions

    OpenAIRE

    Eben Kenah; Miller, Joel C.

    2011-01-01

    Epidemic percolation networks (EPNs) are directed random networks that can be used to analyze stochastic “Susceptible-Infectious-Removed” (SIR) and “Susceptible-Exposed-Infectious-Removed” (SEIR) epidemic models, unifying and generalizing previous uses of networks and branching processes to analyze mass-action and network-based S(E)IR models. This paper explains the fundamental concepts underlying the definition and use of EPNs, using them to build intuition about the final outcomes of epidem...

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

    OpenAIRE

    Hak, E; Loon, S.; Buskens, E; van Essen, G. A.; Bakker, D.; Tacken, M.A.J.B.; van Hout, B.A.; 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, acute respiratory disease (ARD), heart failure, myocardial infarction, depression or diabetes dysregulation. Per case four controls are sampled, frequency matched on age and high-risk co-morbidit...

  8. The neuropsychiatric aspects of influenza/swine flu: A selective review

    OpenAIRE

    Narayana Manjunatha; Suresh Bada Math; Girish Baburao Kulkarni; Santosh Kumar Chaturvedi

    2011-01-01

    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 differen...

  9. New small-molecule drug design strategies for fighting resistant influenza A

    OpenAIRE

    Zuyuan Shen; Kaiyan Lou; Wei Wang

    2015-01-01

    Influenza A virus is the major cause of seasonal or pandemic flu worldwide. Two main treatment strategies–vaccination and small molecule anti-influenza drugs are currently available. As an effective vaccine usually takes at least 6 months to develop, anti-influenza small molecule drugs are more effective for the first line of protection against the virus during an epidemic outbreak, especially in the early stage. Two major classes of anti-influenza drugs currently available are admantane-base...

  10. Epidemiology of Australian Influenza-Related Paediatric Intensive Care Unit Admissions, 1997-2013.

    Directory of Open Access Journals (Sweden)

    Marlena C Kaczmarek

    Full Text Available Influenza virus predictably causes an annual epidemic resulting in a considerable burden of illness in Australia. Children are disproportionately affected and can experience severe illness and complications, which occasionally result in death.We conducted a retrospective descriptive study using data collated in the Australian and New Zealand Paediatric Intensive Care (ANZPIC Registry of influenza-related intensive care unit (ICU admissions over a 17-year period (1997-2013, inclusive in children <16 years old. National laboratory-confirmed influenza notifications were used for comparison.Between 1997 and 2013, a total of 704 influenza-related ICU admissions were recorded, at a rate of 6.2 per 1,000 all-cause ICU admissions. Age at admission ranged from 0 days and 15.9 years (median = 2.1 years, with 135 (19.2% aged <6 months. Pneumonia/pneumonitis and bronchiolitis were the most common primary diagnoses among influenza-related admissions (21.9% and 13.6%, respectively. More than half of total cases (59.2% were previously healthy (no co-morbidities recorded, and in the remainder, chronic lung disease (16.7% and asthma (12.5% were the most common co-morbidities recorded. Pathogen co-detection occurred in 24.7% of cases, most commonly with respiratory syncytial virus or a staphylococcal species. Median length of all ICU admissions was 3.2 days (range 2.0 hours- 107.4 days and 361 (51.3% admissions required invasive respiratory support for a median duration of 4.3 days (range 0.2 hours- 107.5 days. There were 27 deaths recorded, 14 (51.9% in children without a recorded co-morbidity.Influenza causes a substantial number of ICU admissions in Australian children each year with the majority occurring in previously healthy children.

  11. Flu (Influenza)

    Science.gov (United States)

    ... Skip Content Marketing Share this: Main Content Area Flu (Influenza) Overview Influenza, or flu, is a respiratory infection ... the flu and its complications every year. Seasonal Flu Seasonal flu refers to the flu outbreaks that ...

  12. Avian influenza

    Science.gov (United States)

    Bird flu; H5N1; H5N2; H5N8; H7N9; Avian influenza A (HPAI) H5 ... The first avian influenza in humans was reported in Hong Kong in 1997. It was called avian influenza (H5N1). The outbreak was linked ...

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

    OpenAIRE

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

    2011-01-01

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

  14. Avian influenza virus in pregnancy.

    Science.gov (United States)

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

    2016-07-01

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

  15. Anti-Influenza Activity of C60 Fullerene Derivatives

    OpenAIRE

    Shoji, Masaki; Takahashi, Etsuhisa; Hatakeyama, Dai; Iwai, Yuma; Morita, Yuka; Shirayama, Riku; Echigo, Noriko; Kido, Hiroshi; Nakamura, Shigeo; Mashino, Tadahiko; Okutani, Takeshi; Kuzuhara, Takashi

    2013-01-01

    The H1N1 influenza A virus, which originated in swine, caused a global pandemic in 2009, and the highly pathogenic H5N1 avian influenza virus has also caused epidemics in Southeast Asia in recent years. Thus, the threat from influenza A remains a serious global health issue, and novel drugs that target these viruses are highly desirable. Influenza A RNA polymerase consists of the PA, PB1, and PB2 subunits, and the N-terminal domain of the PA subunit demonstrates endonuclease activity. Fullere...

  16. Epidemic percolation networks, epidemic outcomes, and interventions.

    Science.gov (United States)

    Kenah, Eben; Miller, Joel C

    2011-01-01

    Epidemic percolation networks (EPNs) are directed random networks that can be used to analyze stochastic "Susceptible-Infectious-Removed" (SIR) and "Susceptible-Exposed-Infectious-Removed" (SEIR) epidemic models, unifying and generalizing previous uses of networks and branching processes to analyze mass-action and network-based S(E)IR models. This paper explains the fundamental concepts underlying the definition and use of EPNs, using them to build intuition about the final outcomes of epidemics. We then show how EPNs provide a novel and useful perspective on the design of vaccination strategies. PMID:21437002

  17. Is a highly pathogenic avian influenza virus H5N1 fragment recombined in PB1 the key for the epidemic of the novel AIV H7N9 in China, 2013?

    Directory of Open Access Journals (Sweden)

    Liang Chen

    2016-02-01

    Conclusions: The novel AIV H7N9 might have reassorted its PB1 segment from H9N2 circulating in China, and this H9N2 PB1 might have been recombined into a highly pathogenic fragment from HPAIV H5N1, which could be the reason for the high fatality rate among patients with AIV H7N9 influenza.

  18. 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...

  19. Influenza infection and COPD

    OpenAIRE

    Mallia, Patrick; Johnston, Sebastian L.

    2007-01-01

    Influenza is a disease with global impact that causes enormous morbidity and mortality on an annual basis. It primarily infects the respiratory tract and causes a broad range of illness ranging from symptomless infection to fulminant primary viral and secondary bacterial pneumonia. The severity of infection depends on both the virus strain and a number of host factors, primarily age and the presence of comorbid conditions such as cardiopulmonary disease. The mortality and utilization of healt...

  20. Influenza, solar radiation and vitamin D

    OpenAIRE

    Moan, Johan; Dahlback, Arne; Ma, Liwei; Juzeniene, Asta

    2009-01-01

    The annual death numbers of influenza and pneumonia in Norway were studied for the time period 1980–2000. No direct relationships were found with the variations of the annual UVB fluences, probably due to the fact that these variations did not exceed 30%. However, there was a very pronounced seasonal variation of both influenza deaths and pneumonia deaths, the vast majority occurring during the winter. Vitamin D levels were also estimated from several publications. The data support the hypoth...

  1. Roles of the hemagglutinin of influenza A virus in viral entry and development of antiviral therapeutics and vaccines

    OpenAIRE

    Jiang, Shibo; Li, Runming; Du, Lanying; Liu, Shuwen

    2010-01-01

    Seasonal influenza epidemics and influenza pandemics caused by influenza A virus (IAV) has resulted in millions of deaths in the world. The development of anti-IAV vaccines and therapeutics is urgently needed for prevention and treatment of IAV infection and for controlling future influenza pandemics. Hemagglutinin (HA) of IAV plays a critical role in viral binding, fusion and entry, and contains the major neutralizing epitopes. Therefore, HA is an attractive target for developing anti-IAV dr...

  2. Avian Influenza

    OpenAIRE

    Tsung-Zu Wu; Li-Min Huang

    2005-01-01

    Influenza is an old disease but remains vital nowadays. Three types of influenza viruses,namely A, B, C, have been identified; among them influenza A virus has pandemic potential.The first outbreak of human illness due to avian influenza virus (H5N1) occurred in1997 in Hong Kong with a mortality of 30%. The most recent outbreak of the avian influenzaepidemic has been going on in Asian countries since 2003. As of March 2005, 44 incidentalhuman infections and 32 deaths have been documented. Hum...

  3. 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

  4. Risk maps for the spread of highly pathogenic avian influenza in poultry.

    OpenAIRE

    Gert Jan Boender; Hagenaars, Thomas J; Annemarie Bouma; Gonnie Nodelijk; Elbers, Armin R. W; De Jong, Mart C. M.; Michiel van Boven

    2007-01-01

    Devastating epidemics of highly contagious animal diseases such as avian influenza, classical swine fever, and foot-and-mouth disease underline the need for improved understanding of the factors promoting the spread of these pathogens. Here the authors present a spatial analysis of the between-farm transmission of a highly pathogenic H7N7 avian influenza virus that caused a large epidemic in The Netherlands in 2003. The authors developed a method to estimate key parameters determining the spr...

  5. Risk maps for the spread of highly pathogenic avian influenza in poultry

    OpenAIRE

    Boender, G.J.; Hagenaars, T.H.J.; Bouma, A.; Nodelijk, G.; Elbers, A.R.W.; Jong, de, D.; Boven, van, R.M.

    2007-01-01

    Devastating epidemics of highly contagious animal diseases such as avian influenza, classical swine fever, and foot-and-mouth disease underline the need for improved understanding of the factors promoting the spread of these pathogens. Here the authors present a spatial analysis of the between-farm transmission of a highly pathogenic H7N7 avian influenza virus that caused a large epidemic in The Netherlands in 2003. The authors developed a method to estimate key parameters determining the spr...

  6. 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....

  7. Similarities in mortality patterns from influenza in the first half of the 20th century and the rise and fall of ischemic heart disease in the United States: a new hypothesis concerning the coronary heart disease epidemic Semelhanças entre o padrão de mortalidade por influenza na primeira metade do século XX e o padrão de mortalidade por doença isquêmica do coração no transcorrer do século, nos Estados Unidos: uma nova hipótese para a epidemia de cardiopatia isquêmica

    Directory of Open Access Journals (Sweden)

    Maria Inês Reinert Azambuja

    2002-06-01

    Full Text Available The classic risk factors for developing coronary heart disease (CHD explain less than 50% of the decrease in mortality observed since 1950. The transition currently under way, from the degenerative to the infectious-inflammatory paradigm, requires a new causal interpretation of temporal trends. The following is an ecological study based on data from the United States showing that in men and women an association between the age distribution of mortality due to influenza and pneumonia (I&P associated with the influenza pandemic in 1918-1919 in the 10-49-year age bracket and the distribution of CHD mortality from 1920 to 1985 in survivors from the corresponding birth cohorts. It further shows a significant negative correlation (r = -0.68, p = 0.042 between excess mortality from I&P accumulated in epidemics from 1931 to 1940 (used as indicator for persistent circulation of H1N1 virus combined with vulnerability to infection and the order of the beginning in the decline in CHD mortality in nine geographic divisions in the United States. In light of current biological knowledge, the data suggest that the 1918 influenza pandemic and the subsequent epidemics up to 1957 might have played a determinant role in the epidemic of CHD mortality registered in the 20th century.Os fatores de risco clássicos para o desenvolvimento de doença isquêmica do coração (DIC explicam menos de 50% da queda na mortalidade observada desde 1950. A transição em curso, do paradigma degenerativo para o inflamatório/infeccioso, requer nova interpretação causal das tendências temporais. Este é um estudo ecológico, baseado em dados dos Estados Unidos, que mostra, em homens e mulheres, uma associação entre a distribuição etária da mortalidade por influenza e pneumonia (I&P associada à pandemia de influenza de 1918-1919 na faixa dos 10 aos 49 anos e a distribuição da mortalidade por DIC, entre 1920 e 1985, em sobreviventes das coortes de nascimento correspondentes

  8. Hemagglutinin Sequence Conservation Guided Stem Immunogen Design from Influenza A H3 Subtype

    Science.gov (United States)

    Mallajosyula, V. Vamsee Aditya; Citron, Michael; Ferrara, Francesca; Temperton, Nigel J.; Liang, Xiaoping; Flynn, Jessica A.; Varadarajan, Raghavan

    2015-01-01

    Seasonal epidemics caused by influenza A (H1 and H3 subtypes) and B viruses are a major global health threat. The traditional, trivalent influenza vaccines have limited efficacy because of rapid antigenic evolution of the circulating viruses. This antigenic variability mediates viral escape from the host immune responses, necessitating annual vaccine updates. Influenza vaccines elicit a protective antibody response, primarily targeting the viral surface glycoprotein hemagglutinin (HA). However, the predominant humoral response is against the hypervariable head domain of HA, thereby restricting the breadth of protection. In contrast, the conserved, subdominant stem domain of HA is a potential “universal” vaccine candidate. We designed an HA stem-fragment immunogen from the 1968 pandemic H3N2 strain (A/Hong Kong/1/68) guided by a comprehensive H3 HA sequence conservation analysis. The biophysical properties of the designed immunogen were further improved by C-terminal fusion of a trimerization motif, “isoleucine-zipper”, or “foldon”. These immunogens elicited cross-reactive, antiviral antibodies and conferred partial protection against a lethal, homologous HK68 virus challenge in vivo. Furthermore, bacterial expression of these immunogens is economical and facilitates rapid scale-up. PMID:26167164

  9. Genomewide analysis of reassortment and evolution of human influenza A(H3N2) viruses circulating between 1968 and 2011

    NARCIS (Netherlands)

    K.B. Westgeest (Kim); C.A. Russell (Colin); X. Lin (Xudong); M.I. Spronken (Monique); T.M. Bestebroer (Theo); J. Bahl (Justin); R. van Beek (Ruud); E. Skepner (Eugene); R.A. Halpin (Rebecca); J.C. de Jong (Jan); G.F. Rimmelzwaan (Guus); A.D.M.E. Osterhaus (Albert); D.R. Smith (Derek Richard); C.E. Wentworth (Charles); R.A.M. Fouchier (Ron); M.T. de Graaf (Marieke)

    2014-01-01

    textabstractInfluenza A(H3N2) viruses became widespread in humans during the 1968 H3N2 virus pandemic and have been a major cause of influenza epidemics ever since. These viruses evolve continuously by reassortment and genomic evolution. Antigenic drift is the cause for the need to update influenza

  10. Optimizing infectious disease interventions during an emerging epidemic

    OpenAIRE

    Wallinga, J.; van Boven, M.; Lipsitch, M.

    2009-01-01

    The emergence and global impact of the novel influenza A(H1N1)v highlights the continuous threat to public health posed by a steady stream of new and unexpected infectious disease outbreaks in animals and humans. Once an emerging epidemic is detected, public health authorities will attempt to mitigate the epidemic by, among other measures, reducing further spread as much as possible. Scarce and/or costly control measures such as vaccines, anti-infective drugs, and social distancing must be al...

  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. Anti-Influenza Activity of Marchantins, Macrocyclic Bisbibenzyls Contained in Liverworts

    OpenAIRE

    Yuma Iwai; Kouki Murakami; Yasuyuki Gomi; Toshihiro Hashimoto; Yoshinori Asakawa; Yoshinobu Okuno; Toyokazu Ishikawa; Dai Hatakeyama; Noriko Echigo; Takashi Kuzuhara

    2011-01-01

    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 o...

  13. Does a Mature AIDS Epidemic Threaten Growth?

    OpenAIRE

    Cuesta, José

    2008-01-01

    This paper models the impact on economic growth of HIV/AIDS when the epidemic is in a mature phase, in contrast with previous studies focused on periods of expansion, as in African countries. Simulations for Honduras, the epicenter of the epidemic in Central America, show that AIDS is not likely to threaten economic growth through either labor or capital accumulation channels; impacts are estimated between 0. 007 and 0. 27 percent points of GDP growth annually for the period 2001-10. Likewise...

  14. 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.

  15. Quantifying the transmission potential of pandemic influenza

    Science.gov (United States)

    Chowell, Gerardo; Nishiura, Hiroshi

    2008-03-01

    This article reviews quantitative methods to estimate the basic reproduction number of pandemic influenza, a key threshold quantity to help determine the intensity of interventions required to control the disease. Although it is difficult to assess the transmission potential of a probable future pandemic, historical epidemiologic data is readily available from previous pandemics, and as a reference quantity for future pandemic planning, mathematical and statistical analyses of historical data are crucial. In particular, because many historical records tend to document only the temporal distribution of cases or deaths (i.e. epidemic curve), our review focuses on methods to maximize the utility of time-evolution data and to clarify the detailed mechanisms of the spread of influenza. First, we highlight structured epidemic models and their parameter estimation method which can quantify the detailed disease dynamics including those we cannot observe directly. Duration-structured epidemic systems are subsequently presented, offering firm understanding of the definition of the basic and effective reproduction numbers. When the initial growth phase of an epidemic is investigated, the distribution of the generation time is key statistical information to appropriately estimate the transmission potential using the intrinsic growth rate. Applications of stochastic processes are also highlighted to estimate the transmission potential using similar data. Critically important characteristics of influenza data are subsequently summarized, followed by our conclusions to suggest potential future methodological improvements.

  16. Cause of Flu (Influenza)

    Science.gov (United States)

    ... Skip Content Marketing Share this: Main Content Area Flu (Influenza) Cause About the Flu Virus Influenza, or flu, is a respiratory infection ... the virus. Influenza A virus. Credit: CDC Where Influenza Comes From In nature, the flu virus is ...

  17. Surveillance of low pathogenic avian influenza in layer chickens: risk factors, transmission and early detection

    NARCIS (Netherlands)

    Gonzales Rojas, J.L.

    2012-01-01

    Low pathogenic avian influenza virus (LPAIv) of H5 and H7 subtypes are able to mutate to highly pathogenic avian influenza virus (HPAIv), which are lethal for most poultry species, can cause large epidemics and are a serious threat to public health. Thus, circulation of these LPAIv in poultry is und

  18. Prediction of Peaks of Seasonal Influenza in Military Health-Care Data

    OpenAIRE

    Buczak, Anna L; Baugher, Benjamin; Guven, Erhan; Moniz, Linda; Steven M Babin; Chretien, Jean-Paul

    2016-01-01

    Influenza is a highly contagious disease that causes seasonal epidemics with significant morbidity and mortality. The ability to predict influenza peak several weeks in advance would allow for timely preventive public health planning and interventions to be used to mitigate these outbreaks. Because influenza may also impact the operational readiness of active duty personnel, the US military places a high priority on surveillance and preparedness for seasonal outbreaks. A method for creating m...

  19. Swine Influenza/Variant Influenza Viruses

    Science.gov (United States)

    ... Documents (General) Workers Employed at Commercial Swine Farms Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... this? Submit Button Past Newsletters Information on Swine Influenza/Variant Influenza Viruses Language: English Español Recommend ...

  20. Emerging influenza

    OpenAIRE

    de Wit, Emmie; Fouchier, Ron

    2008-01-01

    textabstractIn 1918 the Spanish influenza pandemic, caused by an avian H1N1 virus, resulted in over 50 million deaths worldwide. Several outbreaks of H7 influenza A viruses have resulted in human cases, including one fatal case. Since 1997, the outbreaks of highly pathogenic avian influenza (HPAI) of the H5N1 subtype have affected a wide variety of mammals in addition to poultry and wild birds. Here, we give an overview of the current knowledge of the determinants of pathogenicity of these th...

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

    OpenAIRE

    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 outbreaks in relation to poultry, land use, and other anthropogenic variables from the start of the second epidemic wave (July 2004–May 2005). Results demonstrate a strong association between H5N1 viru...

  3. Projection of seasonal influenza severity from sequence and serological data

    OpenAIRE

    Wolf, Yuri I.; Nikolskaya, Anastasia; Cherry, Joshua L.; Viboud, Cecile; Koonin, Eugene; Lipman, David J.

    2010-01-01

    Severity of seasonal influenza A epidemics is related to the antigenic novelty of the predominant viral strains circulating each year. Support for a strong correlation between epidemic severity and antigenic drift comes from infectious challenge experiments on vaccinated animals and human volunteers, field studies of vaccine efficacy, prospective studies of subjects with laboratory-confirmed prior infections, and analysis of the connection between drift and severity from surveillance data. We...

  4. Replication-Competent Influenza A and B Viruses Expressing a Fluorescent Dynamic Timer Protein for In Vitro and In Vivo Studies.

    Directory of Open Access Journals (Sweden)

    Michael Breen

    Full Text Available Influenza A and B viruses (IAV and IBV, respectively cause annual seasonal human respiratory disease epidemics. In addition, IAVs have been implicated in occasional pandemics with inordinate health and economic consequences. Studying influenza viruses in vitro or in vivo requires the use of laborious secondary methodologies to identify infected cells. To circumvent this requirement, replication-competent infectious influenza viruses expressing an easily traceable fluorescent reporter protein can be used. Timer is a fluorescent protein that undergoes a time-dependent color emission conversion from green to red. The rate of spectral change is independent of Timer protein concentration and can be used to chronologically measure the duration of its expression. Here, we describe the generation of replication-competent IAV and IBV where the viral non-structural protein 1 (NS1 was fused to the fluorescent dynamic Timer protein. Timer-expressing IAV and IBV displayed similar plaque phenotypes and growth kinetics to wild-type viruses in tissue culture. Within infected cells, Timer's spectral shift can be used to measure the rate and cell-to-cell spread of infection using fluorescent microscopy, plate readers, or flow cytometry. The progression of Timer-expressing IAV infection was also evaluated in a mouse model, demonstrating the feasibility to characterize IAV cell-to-cell infections in vivo. By providing the ability to chronologically track viral spread, Timer-expressing influenza viruses are an excellent option to evaluate the in vitro and in vivo dynamics of viral infection.

  5. 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...

  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. Recent zoonoses caused by influenza A viruses.

    Science.gov (United States)

    Alexander, D J; Brown, I H

    2000-04-01

    Influenza is a highly contagious, acute illness which has afflicted humans and animals since ancient times. Influenza viruses are part of the Orthomyxoviridae family and are grouped into types A, B and C according to antigenic characteristics of the core proteins. Influenza A viruses infect a large variety of animal species, including humans, pigs, horses, sea mammals and birds, occasionally producing devastating pandemics in humans, such as in 1918, when over twenty million deaths occurred world-wide. The two surface glycoproteins of the virus, haemagglutinin (HA) and neuraminidase (NA), are the most important antigens for inducing protective immunity in the host and therefore show the greatest variation. For influenza A viruses, fifteen antigenically distinct HA subtypes and nine NA subtypes are recognised at present; a virus possesses one HA and one NA subtype, apparently in any combination. Although viruses of relatively few subtype combinations have been isolated from mammalian species, all subtypes, in most combinations, have been isolated from birds. In the 20th Century, the sudden emergence of antigenically different strains in humans, termed antigenic shift, has occurred on four occasions, as follows, in 1918 (H1N1), 1957 (H2N2), 1968 (H3N2) and 1977 (H1N1), each resulting in a pandemic. Frequent epidemics have occurred between the pandemics as a result of gradual antigenic change in the prevalent virus, termed antigenic drift. Currently, epidemics occur throughout the world in the human population due to infection with influenza A viruses of subtypes H1N1 and H3N2 or with influenza B virus. The impact of these epidemics is most effectively measured by monitoring excess mortality due to pneumonia and influenza. Phylogenetic studies suggest that aquatic birds could be the source of all influenza A viruses in other species. Human pandemic strains are thought to have emerged through one of the following three mechanisms: genetic reassortment (occurring as a

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

    OpenAIRE

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

    2012-01-01

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

  9. 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.

  10. PTSD: A Growing Epidemic

    Science.gov (United States)

    ... plane crashes, bombings, or natural disasters such as floods or earthquakes. The majority of people exposed to ... tell? Read More "Post Traumatic Stress Disorder (PTSD)" Articles PTSD: A Growing Epidemic / Symptoms, Diagnosis, Treatment / NIH ...

  11. 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,...

  12. The Burden of Influenza-Associated Hospitalizations in Oman, January 2008-June 2013.

    Directory of Open Access Journals (Sweden)

    Salah Al-Awaidy

    Full Text Available Acute respiratory infections (ARI, including influenza, comprise a leading cause of morbidity and mortality worldwide. Influenza surveillance provides important information to inform policy on influenza control and vaccination. While the epidemiology of influenza has been well characterized in western countries, few data exist on influenza epidemiology in the Eastern Mediterranean Region. We describe the epidemiology of influenza virus in Oman.Using syndromic case definitions and protocols, patients from four regional hospitals in Oman were enrolled in a descriptive prospective study to characterize the burden of severe acute respiratory infections (SARI and influenza. Eligible patients provided demographic information as well as oropharyngeal (OP and nasopharyngeal (NP swabs. Specimens were tested for influenza A and influenza B; influenza A viruses were subtyped using RT-PCR.From January 2008 through June 2013, a total of 5,147 cases were enrolled and tested for influenza. Influenza strains were detected in 8% of cases for whom samples were available. Annual incidence rates ranged from 0.5 to 15.4 cases of influenza-associated SARI per 100,000 population. The median age of influenza patients was 6 years with children 0-2 years accounting for 34% of all influenza-associated hospitalizations. By contrast, the median age of non-influenza SARI cases was 1 year with children 0-2 years comprising 59% of SARI. Compared to non-influenza SARI cases, a greater proportion of influenza cases had pre-existing chronic conditions and underwent ventilation during hospitalization.Influenza virus is associated with a substantial proportion of SARI in Oman. Influenza in Oman approximately follows northern hemisphere seasonality, with major peaks in October to December and a lesser peak around April. The burden of influenza was greatest in children and the elderly. Future efforts should examine the burden of influenza in other potential risk groups such as

  13. Phylogenetic analysis reveals the global migration of seasonal influenza A viruses.

    Directory of Open Access Journals (Sweden)

    Martha I Nelson

    2007-09-01

    Full Text Available The winter seasonality of influenza A virus in temperate climates is one of the most widely recognized, yet least understood, epidemiological patterns in infectious disease. Central to understanding what drives the seasonal emergence of this important human pathogen is determining what becomes of the virus during the non-epidemic summer months. Herein, we take a step towards elucidating the seasonal emergence of influenza virus by determining the evolutionary relationship between populations of influenza A virus sampled from opposite hemispheres. We conducted a phylogenetic analysis of 487 complete genomes of human influenza A/H3N2 viruses collected between 1999 and 2005 from Australia and New Zealand in the southern hemisphere, and a representative sub-sample of viral genome sequences from 413 isolates collected in New York state, United States, representing the northern hemisphere. We show that even in areas as relatively geographically isolated as New Zealand's South Island and Western Australia, global viral migration contributes significantly to the seasonal emergence of influenza A epidemics, and that this migration has no clear directional pattern. These observations run counter to suggestions that local epidemics are triggered by the climate-driven reactivation of influenza viruses that remain latent within hosts between seasons or transmit at low efficiency between seasons. However, a complete understanding of the seasonal movements of influenza A virus will require greatly expanded global surveillance, particularly of tropical regions where the virus circulates year-round, and during non-epidemic periods in temperate climate areas.

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

    OpenAIRE

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

    2011-01-01

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

  15. Transmission of highly pathogenic avian influenza H7 virus

    OpenAIRE

    Bos, M.E.H.

    2009-01-01

    Knowledge of the transmission of highly pathogenic avian influenza (HPAI) virus still has gaps, complicating epidemic control. A model was developed to back-calculate the day HPAI virus was introduced into a flock, based on within-flock mortality data of the Dutch HPAI H7N7 epidemic (2003). The method was based on a stochastic epidemic model in which birds move from being susceptible, latently infected and infectious, to death. Our results indicated that two weeks can elapse before a noticeab...

  16. Pandemic and Seasonal Influenza: Therapeutic Challenges

    OpenAIRE

    Memoli, Matthew J.; Morens, David M.; Jeffery K Taubenberger

    2008-01-01

    Influenza A viruses cause significant morbidity and mortality annually, and the threat of a pandemic underscores the need for new therapeutic strategies. Here we briefly discuss novel antiviral agents under investigation, the limitations of current antiviral therapy and stress the importance of secondary bacterial infections in seasonal and pandemic influenza. Additionally, the lack of new antibiotics available to treat increasingly drug resistant organisms such as methicillin-resistant Staph...

  17. Prevention of influenza infection – a Polish perspective

    Directory of Open Access Journals (Sweden)

    Lidia Bernadeta Brydak

    2014-02-01

    Full Text Available Influenza is a viral respiratory illness that causes high morbidity and significant mortality in humans. Costs associated with influenza in terms of human suffering are immeasurable and the economic costs are very high. Every year, according to the World Health Organization (WHO, 5-25% of the global population suffers from infection with influenza and influenza-like viruses and between 500 thousand and one million individuals of all ages die from multiple organ complications, irrespective of the geographic location. Influenza vaccination is still neglected and the percentage of the global population vaccinated remains low. The first authorization for the use of influenza vaccines in humans was issued in 1941. Currently, many varieties of influenza vaccine are available, containing either fragments of inactivated influenza virus or live vaccine which consists of attenuated virus. The influenza vaccine is most often developed in chick embryos or less frequently in tissue culture such as MDCK and Vero. A variety of inactivated vaccines are registered in Poland. Due to the mutability of the virus, it is not yet possible to develop a universal vaccine, nor can the disease be eradicated; however, prevention is possible by inoculating the greatest percentage of the global population. According to the WHO, Poland is in the penultimate position in Europe in terms of the percentage of the population vaccinated. In the last epidemic season of 2012/2013 only 3.75% of the Polish population was immunized.

  18. Prevention of influenza infection--a Polish perspective.

    Science.gov (United States)

    Brydak, Lidia Bernadeta; Nitsch-Osuch, Aneta

    2014-01-01

    Influenza is a viral respiratory illness that causes high morbidity and significant mortality in humans. Costs associated with influenza in terms of human suffering are immeasurable and the economic costs are very high. Every year, according to the World Health Organization (WHO), 5-25% of the global population suffers from infection with influenza and influenza-like viruses and between 500 thousand and one million individuals of all ages die from multiple organ complications, irrespective of the geographic location. Influenza vaccination is still neglected and the percentage of the global population vaccinated remains low. The first authorization for the use of influenza vaccines in humans was issued in 1941. Currently, many varieties of influenza vaccine are available, containing either fragments of inactivated influenza virus or live vaccine which consists of attenuated virus. The influenza vaccine is most often developed in chick embryos or less frequently in tissue culture such as MDCK and Vero. A variety of inactivated vaccines are registered in Poland. Due to the mutability of the virus, it is not yet possible to develop a universal vaccine, nor can the disease be eradicated; however, prevention is possible by inoculating the greatest percentage of the global population. According to the WHO, Poland is in the penultimate position in Europe in terms of the percentage of the population vaccinated. In the last epidemic season of 2012/2013 only 3.75% of the Polish population was immunized. PMID:24491905

  19. The Impact of Epidemic, War, Prohibition and Media on Suicide: United States, 1910-1920.

    Science.gov (United States)

    Wasserman, Ira M.

    1992-01-01

    Estimated impact of exogenous social and political events on suicide behavior in the United States between 1910 and 1920. Concluded that World War I did not influence suicide; Great Influenza Epidemic caused suicide to increase; and continuing decline in alcohol consumption from 1910 to 1920 depressed national suicide rates. (Author/NB)

  20. Influenza diagnosis and treatment: a view from clinical practice.

    Science.gov (United States)

    Fleming, D M

    2001-12-29

    Influenza is a descriptive term for respiratory epidemic disease presenting with cough and fever. Influenza viruses are probably the most important of the pathogens that cause this condition. Clinical influenza occurs almost every winter in England and Wales and the outbreaks last 8-10 weeks. In recent years, influenza B virus outbreaks have occurred in January and February, whereas influenza H3N2 virus outbreaks have generally started long before Christmas. Influenza H3N2 virus outbreaks pressurize health service resources in winter more than influenza B viruses, that do not have the same impact in elderly people. Infections with influenza H1N1 viruses are also usually less severe in their impact than those with influenza H3N2 viruses, but, unlike influenza B viruses, influenza H1N1 viruses have a pandemic potential along with influenza H3N2 viruses. A diagnosis of respiratory infection in primary care is based on the presenting symptoms set within the context of the current pattern of consultations of patients with similar illness. Measurement of temperature, inspection of the throat and examination of the chest or ears add a little to the diagnostic process, but in general these procedures do not help in identifying the organism. However, if it is known that influenza viruses are circulating in the community, the probability of influenza as the cause is greatly increased, as was shown in clinical trials of neuraminidase antivirals. Maximum confusion occurs when respiratory syncytial virus (RSV) and influenza cocirculate. Although RSV infection can occur throughout the winter in young children, it assumes more of an epidemic character just before Christmas in children and possibly in adults just after. During seven of the last 20 winters, influenza has been prevalent around Christmas/New Year. In routine virological surveillance of influenza-like illness in the community during the winters of 1997, 1998 and 1999, ca. 30% of swab specimens yielded influenza

  1. Influenza aviar

    OpenAIRE

    Pereda, Ariel

    2006-01-01

    Es una enfermedad contagiosa de las aves causada por un virus que comúnmente infecta solamente a las aves, pero que en raras ocasiones, también puede infectar a otros animales como el cerdo y menos comúnmente aún al hombre. El virus causante es denominado virus de la Influenza Aviar. Esta enfermedad fue reconocida, descripta y denominada Peste Aviar en Italia en 1878. En 1955, se demostró que el virus causante de la enfermedad era en realidad un virus de influenza. El ser humano puede s...

  2. A simple and rapid characterization of influenza virus isolates by monoclonal antibodies in radioimmunoassay

    International Nuclear Information System (INIS)

    Radioimmunoassay is described with infectious allantoic fluid directly bound to solid phase, suitable for the detection and further characterization of influenza virus isolates. This simple and rapid method was applied for the description of isolates obtained from different regions of Czechoslovakia during the influenza epidemic in 1983. The results confirmed that all 13 examined isolates represented influenza A viruses possessing H3 subtype haemagglutinin very similar to haemagglutinin of influenza viruses A/Bangkok/1/79 (H3N2), A/Belgium/2/81 (H3N2) and A/Philippines/2/82 (H3N2). (author)

  3. 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.

  4. 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.

  5. Influenza Neuraminidase

    OpenAIRE

    Air, Gillian M

    2011-01-01

    Influenza neuraminidase is the target of two licensed antivirals that have been very successful, with several more in development. However, neuraminidase has been largely ignored as a vaccine target despite evidence that inclusion of neuraminidase in the subunit vaccine gives increased protection. This article describes current knowledge on the structure, enzyme activity and antigenic significance of neuraminidase.

  6. Influenza, 1918

    OpenAIRE

    Wilson, Iain H.

    2005-01-01

    The worst recorded influenza outbreak took place in 1918, when my uncle, Dr Jules S Martin, was a young doctor in the Royal Army Medical Corps in Mozambique. This letter from his commanding officer gives an insight into the horror of the experience

  7. Latitude-based approach for detecting aberrations of hand, foot, and mouth disease epidemics

    OpenAIRE

    Tang, Jia-Hong; Chan, Ta-Chien; SHIGEMATSU Mika; Hwang, Jing-Shiang

    2015-01-01

    Background Epidemics of hand, foot and mouth disease (HFMD) among children in East Asia have been a serious annual public health problem. Previous studies in China and island-type territories in East Asia showed that the onset of HFMD epidemics evolved with increased latitude. Based on the natural characteristics of the epidemics, we developed regression models for issuing aberration alerts and predictions. Methods HFMD sentinel surveillance data from 2008 to 2014 in Japan are used in this st...

  8. 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.

  9. Religione e morale, quale influenza?

    Directory of Open Access Journals (Sweden)

    Francesco Margoni

    2013-03-01

    Full Text Available Qual è l’influenza della religione sul comportamento morale? L’analisi della letteratura rilevante condotta da Paul Bloom della Yale University, pubblicata sull’Annual Review of Psychology col titolo "Religion, Morality, Evolution", ci aiuta senz’altro a far luce sulla questione. Gli studi scientifici sulla religione sono pochi poiché il fenomeno religioso, in ambito scientifico, sembra ancora destare imbarazzo.

  10. Influenza - flu

    Directory of Open Access Journals (Sweden)

    Valčić Miroslav A.

    2010-01-01

    Full Text Available In epidemiology or in epizootiology, there are some infectious diseases that have potential for significant reduction of the susceptible species population. Over the past few decades, epidemiologists were concentrated on diseases that were 'modern' and made front-page news in tabloids. One should recall diseases like bovine spongiform encephalopathy, SARS and AIDS syndromes. However, we should always be aware of the most dangerous diseases such as our old friend, influenza, or simply, flu. In the past decade, we heard about 'bird' or 'swine' influenza. It is the same disease for different animal species as well as for man. Influenza owes its characteristics to specific virus biology as well as to the epidemiology-epizootiology characteristics of the susceptible species. Antigenic changes that took place thanks to reassortment mechanisms of the viral gene segments cause the onset of the new antigenic combinations of the hemaglutinin and neuraminidase molecules. As a result, new H and/or N antigenic formulas appear for the first time in totally susceptible animal and human populations. That means that in such circumstances, no person in the world is immune to the virus. In that case, such a virus can cause a pandemic with disastrous consequences since influenza is a disease with significant mortality, especially in some segments of the human (as well as animal population. Birds and swine are virus reservoirs, but these species are at the same time live test tubes in which the virus resides, changes and adapts itself not only to the original species but to other species as well. That means that there is no 'bird' or 'swine' flu. Influenza is an infection of several important animal species as well as man that have potential not only for the reduction of the population size but, in case of the human population, for influencing social and economic life. .

  11. The scourge of Asian Flu: in utero exposure to pandemic influenza and the development of a cohort of British children

    OpenAIRE

    Kelly, Elaine

    2009-01-01

    This paper examines the impact of in utero exposure to the Asian influenza pandemic of 1957 upon physical and cognitive development in childhood. Outcome data is provided by the National Child Development Study (NCDS), a panel study of a cohort of British children who were all potentially exposed in the womb. Epidemic effects are identified using geographic variation in a surrogate measure of the epidemic. Results indicate significant detrimental effects of the epidemic upon birth weight and ...

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

    Directory of Open Access Journals (Sweden)

    Erdenebaatariin Soyolmaa

    2012-08-01

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

  13. 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.

  14. Influenza Vaccination of Persons with Cardiovascular Disease in the United States

    OpenAIRE

    Singleton, James A.; Wortley, Pascale; Lu, Peng-jun

    2004-01-01

    People who have cardiovascular disease are at increased risk of hospitalization or death associated with influenza infection, and are included among the high-risk groups for whom annual influenza vaccination is recommended. To measure the progress toward the national year 2000 and 2010 objectives of a 60% annual influenza vaccination of adults with high-risk conditions aged 18 to 64 years, we analyzed data from the 1997 to 2001 National Health Interview Surveys (NHIS) regarding persons with c...

  15. Pandemic influenza and the hospitalist: apocalypse when?

    Science.gov (United States)

    Pile, James C; Gordon, Steven M

    2006-03-01

    Beginning with a cluster of human cases in Hong Kong in 1997, avian influenza (H5N1) has spread progressively through, and beyond, Asia in poultry and other birds; and has resulted in sporadic cases of human disease associated with high mortality. The potential for H5N1 influenza to cause a pandemic of human disease continues to be the subject of intense scrutiny by both the media and the scientific community. While the likelihood of such a prospect is uncertain, the inevitability of future pandemics of influenza is clear. Planning for the eventuality of a virulent influenza pandemic at the local, national and global level is critical to limiting the mortality and morbidity of such an occurrence. Hospitalists have a key role to play in institutional efforts to prepare for a influenza pandemic, and should be aware of lessons that my be applied from both the response to Hurricane Katrina, as well as the severe acute respiratory syndrome (SARS) epidemic. PMID:17219482

  16. Epidemic outbreaks on structured populations

    CERN Document Server

    Vazquez, Alexei

    2007-01-01

    Our chances to halt epidemic outbreaks rely on how accurately we represent the population structure underlying the disease spread. When analyzing global epidemics this force us to consider metapopulation models taking into account intra- and inter-community interactions. Recently Watts et al introduced a metapopulation model which accounts for several features observed in real outbreaks [Watts et al, PNAS 102, 11157 (2005)]. In this work I provide an analytical solution to this model, enhancing our understanding of the model and the epidemic outbreaks it represents. First, I demonstrate that depending on the intra-community expected outbreak size and the fraction of social bridges the epidemic outbreaks die out or there is a finite probability to observe a global epidemics. Second, I show that the global scenario is characterized by resurgent epidemics, their number increasing with increasing the intra-community average distance between individuals. Finally, I present empirical data for the AIDS epidemics sup...

  17. 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...

  18. Influenza A Virus Entry Inhibitors Targeting the Hemagglutinin

    Directory of Open Access Journals (Sweden)

    Shuwen Liu

    2013-01-01

    Full Text Available Influenza A virus (IAV has caused seasonal influenza epidemics and influenza pandemics, which resulted in serious threat to public health and socioeconomic impacts. Until now, only 5 drugs belong to two categories are used for prophylaxis and treatment of IAV infection. Hemagglutinin (HA, the envelope glycoprotein of IAV, plays a critical role in viral binding, fusion and entry. Therefore, HA is an attractive target for developing anti‑IAV drugs to block the entry step of IAV infection. Here we reviewed the recent progress in the study of conformational changes of HA during viral fusion process and the development of HA-based IAV entry inhibitors, which may provide a new choice for controlling future influenza pandemics.

  19. 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

  20. Influenza Vaccines

    OpenAIRE

    Ellebedy, A. H.; Webby, R J

    2009-01-01

    Influenza A viruses pose a substantial threat to the human population whether by purposeful manipulation and release or by the natural process of interspecies transmissions from animal reservoirs. The challenge with preparing for these events with vaccination strategies is that the best forms of protective immunity target the most variably of the viral proteins, hemagglutinin. Add to this even just the natural extent of variation in this protein and the challenges to vaccinologists become gre...

  1. 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 ...

  2. Epidemics on Interconnected Networks

    CERN Document Server

    Dickison, M; Stanley, H E

    2012-01-01

    Populations are seldom completely isolated from their environment. Individuals in a particular geographic or social region may be considered a distinct network due to strong local ties, but will also interact with individuals in other networks. We study the susceptible-infected-recovered (SIR) process on interconnected network systems, and find two distinct regimes. In strongly-coupled network systems, epidemics occur simultaneously across the entire system at a critical infection strength $\\beta_c$, below which the disease does not spread. In contrast, in weakly-coupled network systems, a mixed phase exists below $\\beta_c$ of the coupled network system, where an epidemic occurs in one network but does not spread to the coupled network. We derive an expression for the network and disease parameters that allow this mixed phase and verify it numerically. Public health implications of communities comprising these two classes of network systems are also mentioned.

  3. Critical care during epidemics

    OpenAIRE

    Rubinson, Lewis; O'Toole, Tara

    2005-01-01

    We recommend several actions that could improve hospitals' abilities to deliver critical care during epidemics involving large numbers of victims. In the absence of careful pre-event planning, demand for critical care services may quickly exceed available intensive care unit (ICU) staff, beds and equipment, leaving the bulk of the infected populace without benefit of potentially lifesaving critical care. The toll of death may be inversely proportional to the ability to augment critical care c...

  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. Demographic and spatiotemporal patterns of avian influenza infection at the continental scale, and in relation to annual life cycle of a migratory host

    Science.gov (United States)

    Nallar, Rodolfo; Papp, Zsuzsanna; Epp, Tasha; Leighton, Frederick A.; Swafford, Seth R.; DeLiberto, Thomas J.; Dusek, Robert J.; Ip, Hon S.; Hall, Jeffrey S.; Berhane, Yohannes; Gibbs, Samantha E.J.; Soos, Catherine

    2015-01-01

    Since the spread of highly pathogenic avian influenza (HPAI) H5N1 in the eastern hemisphere, numerous surveillance programs and studies have been undertaken to detect the occurrence, distribution, or spread of avian influenza viruses (AIV) in wild bird populations worldwide. To identify demographic determinants and spatiotemporal patterns of AIV infection in long distance migratory waterfowl in North America, we fitted generalized linear models with binominal distribution to analyze results from 13,574 blue-winged teal (Anas discors, BWTE) sampled in 2007 to 2010 year round during AIV surveillance programs in Canada and the United States. Our analyses revealed that during late summer staging (July-August) and fall migration (September-October), hatch year (HY) birds were more likely to be infected than after hatch year (AHY) birds, however there was no difference between age categories for the remainder of the year (winter, spring migration, and breeding period), likely due to maturing immune systems and newly acquired immunity of HY birds. Probability of infection increased non-linearly with latitude, and was highest in late summer prior to fall migration when densities of birds and the proportion of susceptible HY birds in the population are highest. Birds in the Central and Mississippi flyways were more likely to be infected compared to those in the Atlantic flyway. Seasonal cycles and spatial variation of AIV infection were largely driven by the dynamics of AIV infection in HY birds, which had more prominent cycles and spatial variation in infection compared to AHY birds. Our results demonstrate demographic as well as seasonal, latitudinal and flyway trends across Canada and the US, while illustrating the importance of migratory host life cycle and age in driving cyclical patterns of prevalence.

  6. 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.

  7. The Influenza Virus Enigma

    OpenAIRE

    Salomon, Rachelle; Webster, Robert G.

    2009-01-01

    Both seasonal and pandemic influenza continue to challenge both scientists and clinicians. Drug-resistant H1N1 influenza viruses have dominated the 2009 flu season, and the H5N1 avian influenza virus continues to kill both people and poultry in Eurasia. Here, we discuss the pathogenesis and transmissibility of influenza viruses and we emphasize the need to find better predictors of both seasonal and potentially pandemic influenza.

  8. Blood Screening for Influenza

    OpenAIRE

    Hourfar, Michael Kai; Themann, Anna; Eickmann, Markus; Puthavathana, Pilaipan; Laue, Thomas; Seifried, Erhard; Schmidt, Michael

    2007-01-01

    Influenza viruses, including highly pathogenic avian influenza virus (H5N1), could threaten blood safety. We analyzed 10,272 blood donor samples with a minipool nucleic acid amplication technique. Analytical sensitivity of the method was 804 geq/mL and 444 geq/mL for generic influenza primers and influenza (H5N1) subtype–specific primers. This study demonstrates that such screening for influenza viruses is feasible.

  9. Advances in influenza vaccination

    OpenAIRE

    Reperant, Leslie A.; Rimmelzwaan, Guus F.; Osterhaus, Albert D. M. E.

    2014-01-01

    Influenza virus infections yearly cause high morbidity and mortality burdens in humans, and the development of a new influenza pandemic continues to threaten mankind as a Damoclean sword. Influenza vaccines have been produced by using egg-based virus growth and passaging techniques that were developed more than 60 years ago, following the identification of influenza A virus as an etiological agent of seasonal influenza. These vaccines aimed mainly at eliciting neutralizing antibodies targetin...

  10. Epidemics with pathogen mutation on small-world networks

    Science.gov (United States)

    Shao, Zhi-Gang; Tan, Zhi-Jie; Zou, Xian-Wu; Jin, Zhun-Zhi

    2006-05-01

    We study the dynamical behavior of the epidemiological model with pathogen mutation on small-world networks, and discuss the influence of the immunity duration τR, the cross-immunity threshold hthr, and system size N on epidemic dynamics. A decaying oscillation occurs because of the interplay between the immune response and the pathogen mutation. These results have implications for the interpretation of longitudinal epidemiological data on strain abundance, and they will be helpful to assess the threat of highly pathogenic and mutative viruses, such as avian influenza.

  11. 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.

  12. 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.

  13. A Simple Measure of the Dynamics of Segmented Genomes: An Application to Influenza

    Science.gov (United States)

    Aris-Brosou, Stéphane

    The severity of influenza epidemics, which can potentially become a pandemic, has been very difficult to predict. However, past efforts were focusing on gene-by-gene approaches, while it is acknowledged that the whole genome dynamics contribute to the severity of an epidemic. Here, putting this rationale into action, I describe a simple measure of the amount of reassortment that affects influenza at a genomic scale during a particular year. The analysis of 530 complete genomes of the H1N1 subtype, sampled over eleven years, shows that the proposed measure explains 58% of the variance in the prevalence of H1 influenza in the US population. The proposed measure, denoted nRF, could therefore improve influenza surveillance programs at a minimal cost.

  14. Vaccine Effectiveness Against Laboratory-Confirmed Influenza Hospitalizations Among Elderly Adults During the 2010–2011 Season

    OpenAIRE

    Jeffrey C Kwong; Campitelli, Michael A.; Gubbay, Jonathan B.; Peci, Adriana; Winter, Anne-Luise; Olsha, Romy; Turner, Robert; Rosella, Laura C.; Crowcroft, Natasha S

    2013-01-01

    Background.  Although annual influenza immunization is recommended for adults aged ≥65 years due to the substantial burden of illness, the evidence base for this recommendation is weak. Prior observational studies that examined influenza vaccine effectiveness against nonspecific serious outcomes suffered from selection bias and the lack of laboratory confirmation for influenza infection. The objective of this study was to determine the effectiveness of the 2010–2011 seasonal influenza vaccine...

  15. Prior Population Immunity Reduces the Expected Impact of CTL-Inducing Vaccines for Pandemic Influenza Control

    OpenAIRE

    Bolton, Kirsty J.; McCaw, James M.; Brown, Lorena; Jackson, David; Kedzierska, Katherine; McVernon, Jodie

    2015-01-01

    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 C...

  16. Modulation of influenza virus replication by alteration of sodium ion transport and protein kinase C activity

    OpenAIRE

    Hoffmann, H.-Heinrich; Palese, Peter; Shaw, Megan L.

    2008-01-01

    In recent years, increasing levels of resistance to the four FDA-approved anti-influenza virus drugs have been described and vaccine manufacturers have experienced demands that exceed their capacity. This situation underlines the urgent need for novel antivirals as well as innovations in vaccine production in preparation for the next influenza epidemic. Here we report the development of a cell-based high-throughput screen which we have used for the identification of compounds that modulate in...

  17. 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

    2015-01-01

    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. PMID:26027483

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

    OpenAIRE

    Pio Liberatore; Francesca del Bufalo; Giorgia Bottaro; Pietro Ferrara; Antonio Gatto; Ottavio Vitelli

    2012-01-01

    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 (65 years) 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,...

  19. Heterosubtypic anti-avian H5N1 influenza antibodies in intravenous immunoglobulins from globally separate populations protect against H5N1 infection in cell culture

    OpenAIRE

    Sullivan, John S.; Selleck, Paul W.; Downton, Teena; Boehm, Ingrid; Axell, Anna-Maree; Ayob, Yasmin; Kapitza, Natalie M; Dyer, Wayne; Fitzgerald, Anna; Walsh, Bradley; Lynch, Garry W

    2009-01-01

    With antigenically novel epidemic and pandemic influenza strains persistently on the horizon it is of fundamental importance that we understand whether heterosubtypic antibodies gained from exposures to circulating human influenzas exist and can protect against emerging novel strains. Our studies of IVIG obtained from an infection-naive population (Australian) enabled us to reveal heterosubtypic influenza antibodies that cross react with H5N1. We now expand those findings for an Australian do...

  20. Detection of Influenza and Other Respiratory Viruses Carried Out in the Influenza Project - Monitoring Vaccine Effectiveness (I-MOVE).

    Science.gov (United States)

    Woźniak-Kosek, Agnieszka

    2015-01-01

    The project Influenza Vaccine Effectiveness-Monitoring (I-MOVE) is part of the European research carried out by the ECDC (European Center for Disease Prevention and Control), aimed at monitoring the effectiveness of vaccination in Europe during the growing incidence of flu and influenza-like illnesses in the coming epidemic seasons. Laboratory studies using molecular RT-PCR biology methods for detection of genetic material of influenza virus and other respiratory viruses were performed by Voivodeship Sanitary-Epidemiological Stations in Poland. The validation of the results of swabs taken from the nose and throat were carried out in the Department of Influenza Research, National Influenza Center in Warsaw. The study involved 210 samples from patients across Poland. Positive results were recorded for 72.4 % of the samples; influenza virus type A was detected in 43 and type B in 38 cases, whereas in 71 cases other respiratory viruses were detected, which included Human parainfluenza virus type 1-4; Human respiratory syncytial virus type A and B; Human coronavirus 229E/NL63, OC43; Human rhinovirus type A, B, and C; Human enterovirus; and Human adenovirus. The results show that although influenza viruses predominated in the 2010/2011 season in Poland, other flu-like viruses also abounded. PMID:25252895

  1. 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. PMID:26137785

  2. The role of cellular immunity in Influenza H1N1 population dynamics

    Directory of Open Access Journals (Sweden)

    Duvvuri Venkata R

    2012-11-01

    Full Text Available Abstract Background Pre-existing cellular immunity has been recognized as one of the key factors in determining the outcome of influenza infection by reducing the likelihood of clinical disease and mitigates illness. Whether, and to what extent, the effect of this self-protective mechanism can be captured in the population dynamics of an influenza epidemic has not been addressed. Methods We applied previous findings regarding T-cell cross-reactivity between the 2009 pandemic H1N1 strain and seasonal H1N1 strains to investigate the possible changes in the magnitude and peak time of the epidemic. Continuous Monte-Carlo Markov Chain (MCMC model was employed to simulate the role of pre-existing immunity on the dynamical behavior of epidemic peak. Results From the MCMC model simulations, we observed that, as the size of subpopulation with partially effective pre-existing immunity increases, the mean magnitude of the epidemic peak decreases, while the mean time to reach the peak increases. However, the corresponding ranges of these variations are relatively small. Conclusions Our study concludes that the effective role of pre-existing immunity in alleviating disease outcomes (e.g., hospitalization of novel influenza virus remains largely undetectable in population dynamics of an epidemic. The model outcome suggests that rapid clinical investigations on T-cell assays remain crucial for determining the protection level conferred by pre-existing cellular responses in the face of an emerging influenza virus.

  3. Avian Influenza

    OpenAIRE

    Tjandra Y. Aditama

    2008-01-01

    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...

  4. 玉溪市2009~2012年流感哨点监测流行病学和病原学分析%RESEARCH THE ETIOLOGY AND EPIDEMIOLOGY OF INFLUENZA VIRUS FROM THE SENTRY HOSPITAL IN YUXI FROM 2009 TO 2012

    Institute of Scientific and Technical Information of China (English)

    刘泽

    2013-01-01

    目的:分析玉溪市2009~2012年流感哨点医院ILI(流感样病例)监测结果,探索流感流行特征及规律,为制定预防和控制策略提供依据;方法对2009-2012年国家流感监测哨点医院发热门诊流感样病例(ILI)进行流行病学分布研究,通过实验室分离培养流感病毒,并对流感病毒型别检测和分析;结果2009~2012年,ILI占门诊总数百分率平均为4.25%,年平均采样数为762,标本占ILI百分率平均为6.56%,每年1~3月、10~12月呈现两个发病高峰,ILl主要集中青壮年人群,职业分布以农民和学生为主,流感病毒型别流行特点:2009~2010年以新型甲型H1N1流行为主,2010~2011年以B型流感Victory系列流行为主,2012年以季节流感H3N2l流行为主;结论对玉溪市2009~2012年流感病毒的监测,发现具有时间、人群和不同型别的流行特点,结合实验室结果科学合理地使用疫苗,积极预防和控制流感病毒的流行。%Objective:To study the influenza epidemic characteristics and regularity, by analyzing the results of sentry hospital ILI(Influenza-like illness)from 2009 to 2012 in Yuxi, and to provide the prevention and control process. Methods:The ILI and its epidemiology from the fever outpatient were investigated, influenza virus was isolated and cultured, and the types were analyzed in the laboratory. Results:From 2009 to 2012, the ILI average percentage was 4.25%of the total outpatient, the annual average samples were 762 with the percentage of 6.56%. The periods from January to March and October to December were two incidence peaks. It concentrated on the youth and middle-aged, whose occupations mainly were farmers and students. The epidemiological features of influenza virus were as follow, influenza A (H1N1) pdm09 virus was epidemic in 2009 and 2010, influenza B virus of Victory series was epidemic in 2010 and 2011, influenza A (H3N2) was epidemic in 2012. Conclusion

  5. [Cholera++ epidemic in Kenya].

    Science.gov (United States)

    Paugam, H

    1999-03-01

    A cholera epidemic in 1997 followed on the heels of the 1992 epidemic that claimed thousands of victims in Kenya. This time, it emerged in the Migori district near the Tanzanian border, when a woman who had married in Tanzania brought her five-month-old baby to visit her parents. The infant, who contracted serious diarrhea and vomiting, died before the mother could reach a dispensary. During the funeral, a perfect opportunity for the disease to spread, those attending observed the traditional ritual of touching the corpse, and then ate and drank with the next of kin. Many developed symptoms of cholera, and several died in the next few days, even before first aid could be administered. At the Public Health Laboratory in Nairobi, analyses confirmed the presence of the Ogawa strain of Vibrio cholerae. Given the global reputation of Médecins Sans Frontières [Doctors Without Borders] in the field of cholera, the head of public health for Homa Bay District issued a call for help in August 1997, asking the team to provide preventive solutions and assess the gravity of the situation. Despite intense logistical, technical and health initiatives, the epidemic spread like wildfire. Five months after the initial outbreak, in February 1998, two Canadian nurses working for MSF in Homa Bay hurriedly surveyed the situation in Nyanza Province, which has a population of three million. The author accompanied one of these nurses, Joceline Roy, a Quebecer in her forties, on a tour that lasted more than 15 hours. Roy worked conscientiously, with great precision and energy. This narrative conveys much more than the fatigue and hazards of travel in the developing world; it tells the story of an important, but little publicized, aspect of nursing. PMID:10362941

  6. A Step Closer to Meeting the Threat of Avian Influenza

    OpenAIRE

    Suguitan, Amorsolo L.; McAuliffe, Josephine; Mills, Kimberly L; Jin, Hong; Duke, Greg; Lu, Bin; Luke, Catherine J.; Murphy, Brian; David E Swayne; Kemble, George; Subbarao, Kanta

    2006-01-01

    Editors' Summary Background. Influenza A viruses are classified into subtypes according to two of the proteins from the virus surface, the hemagglutinin (HA) and neuraminidase (NA) proteins, each of which occurs naturally in several different versions. For example, the global epidemic (pandemic) of 1918–1919 was caused by an influenza virus containing subtype 1 hemagglutinin and subtype 1 neuraminidase (H1N1), the 1957–1958 pandemic involved an H2N2 virus, and the 1969 pandemic, H3N2. Since 1...

  7. Modeling the Worldwide Spread of Pandemic Influenza: Baseline Case and Containment Interventions

    OpenAIRE

    Vittoria Colizza; Alain Barrat; Marc Barthelemy; Alain-Jacques Valleron; Alessandro Vespignani

    2007-01-01

    Editors' Summary Background. Seasonal outbreaks (epidemics) of influenza—a viral infection of the nose, throat, and airways—affect millions of people and kill about 500,000 individuals every year. Regular epidemics occur because flu viruses frequently make small changes in the viral proteins (antigens) recognized by the human immune system. Consequently, a person's immune-system response that combats influenza one year provides incomplete protection the next year. Occasionally, a human influe...

  8. 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.

  9. Interaction of nanodiamonds materials with influenza viruses

    International Nuclear Information System (INIS)

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

  10. Age distribution of influenza like illness cases during post-pandemic A(H3N2: comparison with the twelve previous seasons, in France.

    Directory of Open Access Journals (Sweden)

    Clément Turbelin

    Full Text Available 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(H1N1pdm09 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.

  11. Psychogenic epidemics and work.

    Science.gov (United States)

    Olkinuora, M

    1984-12-01

    Psychogenic epidemics cover various forms of collective behavior and include mass hysteria, mass psychogenic illness, and hysterical contagion for which no physical explanation can be found. The typical course of a psychogenic epidemic at a workplace progresses from sudden onset, often with dramatic symptoms, to a rapidly attained peak that draws much publicity and is followed by quick disappearance of the symptoms. Over 90% of the affected persons are women, and the symptoms range from dizziness, vomiting, nausea, and fainting to epileptic-type seizures, hyperventilation, and skin disorders. The background mechanisms are thought to be generalized beliefs and triggering events which create a sense of threat that leads to a physiological state of arousal. This state, in turn, creates new beliefs which give meaning to the sense of arousal. The new belief spreads through sociometric channels. Predisposing factors include boredom, pressure to produce, physical stressors, poor labor-management relations, and impaired interpersonal communications, and lack of social support. It is important that a thorough investigation be carried out in all instances. Investigation is not only necessary for diagnosis, but it also reassures the management, the employees, and the press that physical factors are unlikely to be responsible for the disease. PMID:6535252

  12. Avian influenza viruses - new causative a gents of human infections

    Directory of Open Access Journals (Sweden)

    Hrnjaković-Cvjetković Ivana

    2006-01-01

    Full Text Available Introduction. Influenza A viruses can infect humans, some mammals and especially birds. Subtypes of human influenza A viruses: ACH1N1, ACH2N2 and A(H3N2 have caused pandemics. Avian influenza viruses vary owing to their 15 hemagglutinins (H and 9 neuraminidases (N. Human cases of avian influenza A In the Netherlands in 2003, there were 83 human cases of influenza A (H7N7. In 1997, 18 cases of H5N1 influenza A, of whom 6 died, were found among residents of Hong Kong. In 2004, 34 human cases (23 deaths were reported in Viet Nam and Thailand. H5N1 virus-infected patients presented with fever and respiratory symptoms. Complications included respiratory distress syndrome, renal failure, liver dysfunction and hematologic disorders. Since 1999, 7 cases of human influenza H9N2 infection have been identified in China and Hong Kong. The importance of human infection with avian influenza viruses. H5N1 virus can directly infect humans. Genetic reassortment of human and avian influenza viruses may occur in humans co infected with current human A(HIN1 or A(H3N2 subtypes and avian influenza viruses. The result would be a new influenza virus with pandemic potential. All genes of H5Nl viruses isolated from humans are of avian origin. Prevention and control. The reassortant virus containing H and N from avian and the remaining proteins from human influenza viruses will probably be used as a vaccine strain. The most important control measures are rapid destruction of all infected or exposed birds and rigorous disinfection of farms. Individuals exposed to suspected animals should receive prophylactic treatment with antivirals and annual vaccination. .

  13. 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

  14. Prevention and treatment of influenza in the primary care office.

    Science.gov (United States)

    Golovyan, Dmitriy M; Mossad, Sherif B

    2014-03-01

    Influenza, a common respiratory infection, is a source of significant rates of illness, death, and loss of productivity. Annual vaccination is safe and effective in preventing disease and in reducing its severity. Yet a majority of eligible US adults do not receive the annual vaccine, at least in part because of misunderstandings about adverse reactions and clinical effectiveness. PMID:24591474

  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. 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.

  17. FastStats: Influenza

    Science.gov (United States)

    ... this? Submit What's this? Submit Button NCHS Home Influenza Recommend on Facebook Tweet Share Compartir Data are ... 6 months to 17 years who received an influenza vaccination during the past 12 months: 49.9% ...

  18. Avian Influenza in Birds

    Science.gov (United States)

    ... Research Making a Candidate Vaccine Virus Related Links Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... Submit What's this? Submit Button Past Newsletters Avian Influenza in Birds Language: English Español Recommend on ...

  19. Avian Influenza (Bird Flu)

    Science.gov (United States)

    ... Research Making a Candidate Vaccine Virus Related Links Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... this? Submit Button Past Newsletters Information on Avian Influenza Language: English Español Recommend on Facebook Tweet ...

  20. Seasonal Influenza Questions & Answers

    Science.gov (United States)

    ... Medscape Podcasts Public Service Announcements (PSAs) Virus Images Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... Submit What's this? Submit Button Past Newsletters Seasonal Influenza, More Information Questions & Answers Language: English Español ...

  1. Treating Influenza (Flu)

    Science.gov (United States)

    ... can be used to treat influenza illness. Antiviral drugs fight influenza viruses in your body. They are different from ... chills and fatigue. Your doctor may prescribe antiviral drugs to treat your flu illness. Should Istill get aflu vaccine? Yes. Antiviral ...

  2. Engineering influenza viral vectors

    OpenAIRE

    Li, Junwei; Arévalo, Maria T; Zeng, Mingtao

    2013-01-01

    The influenza virus is a respiratory pathogen with a negative-sense, segmented RNA genome. Construction of recombinant influenza viruses in the laboratory was reported starting in the 1980s. Within a short period of time, pioneer researchers had devised methods that made it possible to construct influenza viral vectors from cDNA plasmid systems. Herein, we discuss the evolution of influenza virus reverse genetics, from helper virus-dependent systems, to helper virus-independent 17-plasmid sys...

  3. Antiviral resistance: influenza B

    OpenAIRE

    Conde, Patrícia; Guiomar, Raquel; Cristóvão, Paula; Pechirra, Pedro

    2013-01-01

    Currently circulating influenza viruses are resistant to adamantanes and except for a low number of sporadic cases most are sensitive to neuraminidase inhibitors (NI). Adamantanes are ineffective against influenza B viruses and although NI-resistant influenza B viruses have been rarely reported, recently in the United States was identified one cluster of influenza B viruses with reduced susceptibility to NI and with the I221V substitution in the active site of the neuraminidase. Despite the l...

  4. Influenza diagnosis and control

    OpenAIRE

    Mak, Wai-yin; 麥慧妍

    2012-01-01

    The evolution and spread of influenza virus impose great impact on the society in the past century. Humans are still facing the zoonotic threat arising from animal influenza viruses; however, the existing knowledge is not sufficient to provide an accurate prediction of the next pandemic strain. My objective is to put forward the preparedness for influenza pandemics in two ways: molecular diagnosis and cross-protective vaccine. Influenza gene reassortment can take place during co-infection...

  5. Influenza: an emerging disease.

    OpenAIRE

    Webster, R. G.

    1998-01-01

    Because all known influenza A subtypes exist in the aquatic bird reservoir, influenza is not an eradicable disease; prevention and control are the only realistic goals. If people, pigs, and aquatic birds are the principal variables associated with interspecies transfer of influenza virus and the emergence of new human pandemic strains, influenza surveillance in these species is indicated. Live-bird markets housing a wide variety of avian species together (chickens, ducks, geese, pigeon, turke...

  6. Combination Chemotherapy for Influenza

    OpenAIRE

    Robert G. Webster; Govorkova, Elena A.

    2010-01-01

    The emergence of pandemic H1N1 influenza viruses in April 2009 and the continuous evolution of highly pathogenic H5N1 influenza viruses underscore the urgency of novel approaches to chemotherapy for human influenza infection. Anti-influenza drugs are currently limited to the neuraminidase inhibitors (oseltamivir and zanamivir) and to M2 ion channel blockers (amantadine and rimantadine), although resistance to the latter class develops rapidly. Potential targets for the development of new anti...

  7. Continuing challenges in influenza

    OpenAIRE

    Robert G. Webster; Govorkova, Elena A.

    2014-01-01

    Influenza is an acute respiratory disease in mammals and domestic poultry that emerges from zoonotic reservoirs in aquatic birds and bats. Although influenza viruses are among the most intensively studied pathogens, existing control options require further improvement. Influenza vaccines must be regularly updated because of continuous antigenic drift and sporadic antigenic shifts in the viral surface glycoproteins. Currently, influenza therapeutics are limited to neuraminidase inhibitors; nov...

  8. Control of Influenza

    OpenAIRE

    2004-01-01

    Influenza is the classic emerging infection. Despite the availability of relatively inexpensive vaccines and specific treatments, influenza is the least controlled vaccine-preventable disease. Vaccination coverage of high-risk patients has improved, but all-cause mortality attributable to influenza continues to increase. A supplemental strategy is to vaccinate the principal disseminators of influenza in the community: school children and working adults. The availability of the live, attenuate...

  9. 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.

  10. Prediction of Peaks of Seasonal Influenza in Military Health-Care Data

    Science.gov (United States)

    Buczak, Anna L.; Baugher, Benjamin; Guven, Erhan; Moniz, Linda; Babin, Steven M.; Chretien, Jean-Paul

    2016-01-01

    Influenza is a highly contagious disease that causes seasonal epidemics with significant morbidity and mortality. The ability to predict influenza peak several weeks in advance would allow for timely preventive public health planning and interventions to be used to mitigate these outbreaks. Because influenza may also impact the operational readiness of active duty personnel, the US military places a high priority on surveillance and preparedness for seasonal outbreaks. A method for creating models for predicting peak influenza visits per total health-care visits (ie, activity) weeks in advance has been developed using advanced data mining techniques on disparate epidemiological and environmental data. The model results are presented and compared with those of other popular data mining classifiers. By rigorously testing the model on data not used in its development, it is shown that this technique can predict the week of highest influenza activity for a specific region with overall better accuracy than other methods examined in this article. PMID:27127415

  11. Prediction of Peaks of Seasonal Influenza in Military Health-Care Data.

    Science.gov (United States)

    Buczak, Anna L; Baugher, Benjamin; Guven, Erhan; Moniz, Linda; Babin, Steven M; Chretien, Jean-Paul

    2016-01-01

    Influenza is a highly contagious disease that causes seasonal epidemics with significant morbidity and mortality. The ability to predict influenza peak several weeks in advance would allow for timely preventive public health planning and interventions to be used to mitigate these outbreaks. Because influenza may also impact the operational readiness of active duty personnel, the US military places a high priority on surveillance and preparedness for seasonal outbreaks. A method for creating models for predicting peak influenza visits per total health-care visits (ie, activity) weeks in advance has been developed using advanced data mining techniques on disparate epidemiological and environmental data. The model results are presented and compared with those of other popular data mining classifiers. By rigorously testing the model on data not used in its development, it is shown that this technique can predict the week of highest influenza activity for a specific region with overall better accuracy than other methods examined in this article. PMID:27127415

  12. Influenza, Winter Olympiad, 2002

    OpenAIRE

    Gundlapalli, Adi V.; Rubin, Michael A.; Samore, Matthew H; Lopansri, Bert; Lahey, Timothy; McGuire, Heather L.; Winthrop, Kevin L; Dunn, James J.; Willick, Stuart E.; Vosters, Randal L.; Waeckerle, Joseph F.; Carroll, Karen C.; Gwaltney, Jack M.; Hayden, Frederick G.; Elstad, Mark R.

    2006-01-01

    Prospective surveillance for influenza was performed during the 2002 Salt Lake City Winter Olympics. Oseltamivir was administered to patients with influenzalike illness and confirmed influenza, while their close contacts were given oseltamivir prophylactically. Influenza A/B was diagnosed in 36 of 188 patients, including 13 athletes. Prompt management limited the spread of this outbreak.

  13. About Haemophilus influenzae Disease

    Science.gov (United States)

    ... one that most people are familiar with is Haemophilus influenzae type b, or Hib. There’s a vaccine that can prevent disease caused by Hib, but not the other types of Haemophilus influenzae . Types of Infection Haemophilus influenzae Can Cause Infections ...

  14. Deployable laboratory response to influenza pandemic; PCR assay field trials and comparison with reference methods.

    Directory of Open Access Journals (Sweden)

    Timothy J J Inglis

    Full Text Available BACKGROUND: The influenza A/H1N1/09 pandemic spread quickly during the Southern Hemisphere winter in 2009 and reached epidemic proportions within weeks of the official WHO alert. Vulnerable population groups included indigenous Australians and remote northern population centres visited by international travellers. At the height of the Australian epidemic a large number of troops converged on a training area in northern Australia for an international exercise, raising concerns about their potential exposure to the emerging influenza threat before, during and immediately after their arrival in the area. Influenza A/H1N1/09 became the dominant seasonal variant and returned to Australia during the Southern winter the following year. METHODS: A duplex nucleic acid amplification assay was developed within weeks of the first WHO influenza pandemic alert, demonstrated in northwestern Australia shortly afterwards and deployed as part of the pathology support for a field hospital during a military exercise during the initial epidemic surge in June 2009. RESULTS: The nucleic acid amplification assay was twice as sensitive as a point of care influenza immunoassay, as specific but a little less sensitive than the reference laboratory nucleic acid amplification assay. Repetition of the field assay with blinded clinical samples obtained during the 2010 winter influenza season demonstrated a 91.7% congruence with the reference laboratory method. CONCLUSIONS: Rapid in-house development of a deployable epidemic influenza assay allowed a flexible laboratory response, effective targeting of limited disease control resources in an austere military environment, and provided the public health laboratory service with a set of verification tools for resource-limited settings. The assay method was suitable for rapid deployment in time for the 2010 Northern winter.

  15. FLU, an amino acid substitution model for influenza proteins

    OpenAIRE

    Gascuel Olivier; Le Quang; Dang Cuong; Le Vinh

    2010-01-01

    Abstract Background The amino acid substitution model is the core component of many protein analysis systems such as sequence similarity search, sequence alignment, and phylogenetic inference. Although several general amino acid substitution models have been estimated from large and diverse protein databases, they remain inappropriate for analyzing specific species, e.g., viruses. Emerging epidemics of influenza viruses raise the need for comprehensive studies of these dangerous viruses. We p...

  16. FLU, an amino acid substitution model for influenza proteins

    Directory of Open Access Journals (Sweden)

    Gascuel Olivier

    2010-04-01

    Full Text Available Abstract Background The amino acid substitution model is the core component of many protein analysis systems such as sequence similarity search, sequence alignment, and phylogenetic inference. Although several general amino acid substitution models have been estimated from large and diverse protein databases, they remain inappropriate for analyzing specific species, e.g., viruses. Emerging epidemics of influenza viruses raise the need for comprehensive studies of these dangerous viruses. We propose an influenza-specific amino acid substitution model to enhance the understanding of the evolution of influenza viruses. Results A maximum likelihood approach was applied to estimate an amino acid substitution model (FLU from ~113, 000 influenza protein sequences, consisting of ~20 million residues. FLU outperforms 14 widely used models in constructing maximum likelihood phylogenetic trees for the majority of influenza protein alignments. On average, FLU gains ~42 log likelihood points with an alignment of 300 sites. Moreover, topologies of trees constructed using FLU and other models are frequently different. FLU does indeed have an impact on likelihood improvement as well as tree topologies. It was implemented in PhyML and can be downloaded from ftp://ftp.sanger.ac.uk/pub/1000genomes/lsq/FLU or included in PhyML 3.0 server at http://www.atgc-montpellier.fr/phyml/. Conclusions FLU should be useful for any influenza protein analysis system which requires an accurate description of amino acid substitutions.

  17. Influenza virus neuraminidase (NA): a target for antivirals and vaccines.

    Science.gov (United States)

    Jagadesh, Anitha; Salam, Abdul Ajees Abdul; Mudgal, Piya Paul; Arunkumar, Govindakarnavar

    2016-08-01

    Influenza, the most common infectious disease, poses a great threat to human health because of its highly contagious nature and fast transmissibility, often leading to high morbidity and mortality. Effective vaccination strategies may aid in the prevention and control of recurring epidemics and pandemics associated with this infectious disease. However, antigenic shifts and drifts are major concerns with influenza virus, requiring effective global monitoring and updating of vaccines. Current vaccines are standardized primarily based on the amount of hemagglutinin, a major surface antigen, which chiefly constitutes these preparations along with the varying amounts of neuraminidase (NA). Anti-influenza drugs targeting the active site of NA have been in use for more than a decade now. However, NA has not been approved as an effective antigenic component of the influenza vaccine because of standardization issues. Although some studies have suggested that NA antibodies are able to reduce the severity of the disease and induce a long-term and cross-protective immunity, a few major scientific issues need to be addressed prior to launching NA-based vaccines. Interestingly, an increasing number of studies have shown NA to be a promising target for future influenza vaccines. This review is an attempt to consolidate studies that reflect the strength of NA as a suitable vaccine target. The studies discussed in this article highlight NA as a potential influenza vaccine candidate and support taking the process of developing NA vaccines to the next stage. PMID:27255748

  18. 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.

  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. A case management approach to immunizing patients at high risk for influenza.

    Science.gov (United States)

    Kreager, A M; Cicerone, J; Hella, S; Johnson, A N; Matthews, L; Richards, N L; Sinishtaj, L; Tobin, A; Veltigian, S

    2001-01-01

    The influenza season affects not only the people afflicted with influenza, but the healthcare system as a whole. An estimated dollar 12 billion is the annual cost to care for these patients. An existing problem is that although there is an immunization for influenza, many patients at high risk are not immunized. This article will describe an innovative program of a large Midwest suburban hospital to immunize patients at high risk. PMID:16398063

  1. 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...

  2. Social contact patterns and control strategies for influenza in the elderly.

    Science.gov (United States)

    Towers, S; Feng, Z

    2012-12-01

    Despite dramatic increases in influenza vaccination coverage in the elderly population over the past 30 years, influenza mortality rates have remained static in this age group. Children are believed to be the primary spreaders of diseases such as influenza due to their high degree of inter-contact in school settings, and several studies have examined control of influenza in the entire population, including the elderly, via targeted vaccination of school children. However, such vaccination programs are expensive, and fraught with difficulties of public perception of what may be seen as an unnecessary vaccination against a disease that is normally mild in the children themselves. In the study presented here, we examine the control of influenza in the elderly using simple social distancing measures during an influenza epidemic. The recent work of Glasser et al. characterizes daily contact interactions within the population in terms of preferential mixing between age group peers, co-workers, and parents and children. We expand upon this to include interactions between grandparents and grandchildren, and fit the parameters of this formulation to the recently published social contact survey data of Mossong et al. Using this formulation, we then model an influenza epidemic with an age-structured deterministic disease model and examine how reduction in contacts between grandchildren and grandparents affects the spread of influenza to the elderly. We find that over 50% of all influenza infections in the elderly are caused by direct contact with an infected child, and we determine that social distancing between grandparents and grandchildren is remarkably effective, and is capable of reducing influenza attack rates in the elderly by up to 60%. PMID:22877728

  3. 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

  4. Serological evidence of H3N8 canine influenza-like virus circulation in USA dogs prior to 2004.

    Science.gov (United States)

    Anderson, T C; Bromfield, C R; Crawford, P C; Dodds, W J; Gibbs, E P J; Hernandez, J A

    2012-03-01

    H3N8 canine influenza virus (H3N8 CIV) was first reported as a novel canine respiratory pathogen in racing greyhounds and shelter dogs in the U.S.A. in 2004. Phylogenetic analyses determined that this host-adapted pathogen originated from interspecies transmission of an equine influenza virus (EIV), but it is unknown when the transmission occurred prior to discovery in 2004. The objective of this study was to determine if racing greyhound and shelter dog sera collected from 1984 to 2004 had serological evidence of exposure to H3N8 CIV or EIV. Archived sera from 702 racing greyhounds and 1568 shelter dogs were tested for H3 antibodies to the original 2004 CIV isolate, as well as EIV isolates from 1991 to 1999. None of the racing greyhounds from 1984 and 1985 had detectable H3 antibodies. One of the shelter dogs, which entered a north Florida shelter in 2004, was seropositive. For racing greyhounds sampled from 1999 to 2004, 133/520 (26%) dogs had antibodies to both CIV and EIV H3 proteins. The annual seroprevalence was 27% in 1999, 28% in 2000, 10% in 2001, 1% in 2002, 41% in 2003, and 28% in 2004. The odds of H3 seropositivity were greater among dogs that raced > or =6 months, raced on > or =2 tracks, and raced in 1998, 2002, and 2003. Many of the seropositive dogs raced at tracks that were involved in 'kennel cough' epidemics in 1998-1999 and 2002-2003. Based on serological evidence, a H3N8 canine influenza-like virus was circulating in racing greyhounds in the U.S.A. as early as 1999. PMID:22178358

  5. 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.

  6. Regional Level Influenza Study with Geo-Tagged Twitter Data.

    Science.gov (United States)

    Wang, Feng; Wang, Haiyan; Xu, Kuai; Raymond, Ross; Chon, Jaime; Fuller, Shaun; Debruyn, Anton

    2016-08-01

    The rich data generated and read by millions of users on social media tells what is happening in the real world in a rapid and accurate fashion. In recent years many researchers have explored real-time streaming data from Twitter for a broad range of applications, including predicting stock markets and public health trend. In this paper we design, implement, and evaluate a prototype system to collect and analyze influenza statuses over different geographical locations with real-time tweet streams. We investigate the correlation between the Twitter flu counts and the official statistics from the Center for Disease Control and Prevention (CDC) and discover that real-time tweet streams capture the dynamics of influenza cases at both national and regional level and could potentially serve as an early warning system of influenza epidemics. Furthermore, we propose a dynamic mathematical model which can forecast Twitter flu counts with high accuracy. PMID:27372953

  7. Detecting signals of seasonal influenza severity through age dynamics

    DEFF Research Database (Denmark)

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

    2015-01-01

    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......' 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...... based on the relative risk of influenza-like illness (ILI) among working-age adults to that among school-aged children using weekly outpatient medical claims. We compared our relative risk-based indexes to the composite benchmark and estimated seasonal severity for flu seasons from 2001-02 to 2008...

  8. Development of a stable liquid formulation of live attenuated influenza vaccine.

    Science.gov (United States)

    White, Jessica A; Estrada, Marcus; Flood, E Alexander; Mahmood, Kutub; Dhere, Rajeev; Chen, Dexiang

    2016-07-12

    Vaccination is the most effective means of preventing influenza. However, the cost of producing annual seasonal influenza vaccines puts them out of reach for most developing countries. While live attenuated influenza vaccines are among the most efficacious and can be manufactured at low cost, they may require lyophilization to be stable enough for developing-country use, which adds a significant cost burden. The development of a liquid live attenuated seasonal influenza vaccine that is stable for around a year-the duration of an annual influenza season-would significantly improve not only the production output but also the use and accessibility of influenza vaccines in low-resource settings. In this study, potential stabilizing excipients were screened and optimized using the least stable influenza vaccine strain presently known, H1N1 (A/California/07/2009), as a model. The stability-conferring properties of the lead formulations were also tested with a Type B strain of influenza virus (B/Brisbane/60/2008). Stability was also evaluated with higher titers of influenza virus and exposure to agitation and freeze-thaw stresses to further confirm the stability of the lead formulations. Through this process, we identified a liquid formulation consisting of sucrose phosphate glutamate buffer with 1% arginine and 0.5% recombinant human serum albumin that provided storage stability of one year at 2-8°C for the influenza A and B strains tested. PMID:27155495

  9. [Influenza in heterothermic animals].

    Science.gov (United States)

    Mancini, Dalva Assunção Portari; Mendonça, Rita Maria Zucatelli; Cianciarullo, Aurora Marques; Kobashi, Leonardo Setsuo; Trindade, Hermínio Gomes; Fernandes, Wilson; Pinto, José Ricardo

    2004-01-01

    The objective was to study Orthomyxovirus in heterothermic animals. Blood samples from snakes (genus Bothrops and Crotalus) and from toads and frogs (genus Bufo and Rana) were collected to evaluate the red cell receptors and antibodies specific to influenza virus by the hemagglutination and hemagglutination inhibition tests, respectively. Both snakes and toads kept in captivity presented receptors in their red cells and antibodies specific to either influenza virus type A (human and equine origin) or influenza type B. The same was observed with recently captured snakes. Concerning the influenza hemagglutination inhibition antibodies protective levels were observed in the reptiles' serum, against influenza type A and type B. Unlike the toads, 83.3% of the frogs presented mean levels of Ab 40HIU for some influenza strains. It was concluded that heterothermic animals could offer host conditions to the influenza virus and also susceptibility to the infection. PMID:15330057

  10. 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

  11. 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

  12. 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

  13. 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.

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

    Science.gov (United States)

    2011-12-19

    ...The National Vaccine Program Office (NVPO), on behalf of the National Vaccine Advisory Committee (NVAC), Healthcare Personnel Influenza Vaccination Subgroup (HCPIVS), will host an informational webinar to introduce the committee's draft report and draft recommendations for annually achieving 90% influenza vaccination coverage among healthcare personnel, as stated in the Healthy People 2020......

  16. An effective immunization strategy for airborne epidemics in modular and hierarchical social contact network

    Science.gov (United States)

    Song, Zhichao; Ge, Yuanzheng; Luo, Lei; Duan, Hong; Qiu, Xiaogang

    2015-12-01

    Social contact between individuals is the chief factor for airborne epidemic transmission among the crowd. Social contact networks, which describe the contact relationships among individuals, always exhibit overlapping qualities of communities, hierarchical structure and spatial-correlated. We find that traditional global targeted immunization strategy would lose its superiority in controlling the epidemic propagation in the social contact networks with modular and hierarchical structure. Therefore, we propose a hierarchical targeted immunization strategy to settle this problem. In this novel strategy, importance of the hierarchical structure is considered. Transmission control experiments of influenza H1N1 are carried out based on a modular and hierarchical network model. Results obtained indicate that hierarchical structure of the network is more critical than the degrees of the immunized targets and the modular network layer is the most important for the epidemic propagation control. Finally, the efficacy and stability of this novel immunization strategy have been validated as well.

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

    Science.gov (United States)

    Wang, WenBin; Wu, ZiNiu; Wang, ChunFeng; Hu, RuiFeng

    2013-11-01

    A model based on a thermodynamic approach is proposed for predicting the dynamics of communicable epidemics assumed to be 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 and time-dependent coefficient, the functional form of this coefficient is found through four constraints, including notably the existence of an inflexion point and a maximum. The model is solved to give a log-normal distribution for the spread rate, for which a Shannon entropy can be defined. The only parameter, that characterizes the width of the distribution function, is uniquely determined through maximizing the rate of entropy production. This entropy-based thermodynamic (EBT) model predicts the number of hospitalized cases with a reasonable accuracy for SARS in the year 2003. This EBT model can be of use for potential epidemics such as avian influenza and H7N9 in China.

  18. Analysis on Influenza Surveillance in Futian District of Shenzhen City during 2007-2009%深圳市福田区2007-2009年流行性感冒监测分析

    Institute of Scientific and Technical Information of China (English)

    范苏云; 黄慈林; 石向辉; 李丽廉; 刘莹

    2011-01-01

    目的 了解福田区流行性感冒(简称流感)流行动态及流感病毒毒株的变异情况,为流感的防治提供科学依据.方法 每周统计监测点流感样病例(ILI)数据,采集流感样病例鼻咽拭子标本,采用MDCK细胞进行流感病毒分离,采用血凝抑制试验进行流感病毒犁别的鉴定.结果 2007-2009年共监测到流感样病例32 961例,占监测门诊总数的5.61%;分离阳性毒株363份,分离率34.41%.各年度ILI%趋势与病毒分离率一致.发生暴发疫情97宗,主要发牛在中小学和托幼机构.结论 福田区流感流行高峰在6-8月,各亚型交替出现,一般在6月前后出现毒株型别改变.2009年ILI%、分离率及暴发疫情的升高主要是由于甲型H1N1流感大流行引起的.%[ Objective ] To understand the dynamic epidemiologic characteristics of influenza and variation of influenza virus strains in Futian District, and provide scientific basis for the prevention and treatment of influenza. [ Methods] Influenza-like illness ( ILI) data of monitoring hospitals were weekly analyzed and the nasopharyngeal swab samples of ILI were collected. MDCK cells were used for influenza virus isolation. Hemagglutination inhibition experiments were applied to identify influenza virus type. [ Results ] From 2007 to 2009, a total of 32 961 cases of ILI were monitored, accounting for 5.61% of total monitoring out-patients; 363 influenza strains were isolated, the virus isolation rate was 34.41%. The annual trend of ILI% was consistent with the trend of virus isolation rate; 97 epidemic outbreaks occurred mainly in schools and nurseries. [ Conclusion ] The epidemiologic peak of influenza is from June to August in Futian District, the influenza virus subtypes alternate, the virus strain type usually changed in June. The ILI% and the isolation rate and the epidemic outbreaks increasing is mainly due to influenza pandemic of H1N1 in 2009.

  19. Antigenic Drift of A/H3N2/Virus and Circulation of Influenza-Like Viruses During the 2014/2015 Influenza Season in Poland.

    Science.gov (United States)

    Bednarska, K; Hallmann-Szelińska, E; Kondratiuk, K; Brydak, L B

    2016-01-01

    Morbidity rates of influenza could be greatly reduced due to vaccination. However, the virus is able to evolve through genetic mutations, which is why vaccines with updated composition are necessary every season. Their effectiveness depends on whether there is a good antigenic match between circulating viruses and vaccine strains. In Poland, the 2014/2015 influenza epidemic started in week 5 (January/February) of 2015 and continued until week 17 (April) of 2015. The influenza activity was moderate with the highest incidence of influence-like illness at week 10/2015 (March). During that season, antigenic drift of influenza virus A/H3N2/ occurred causing higher rates of A/H3N2/ infections. Among the 2416 tested specimens, 22.6 % of influenza cases were positive for A/H3N2/, while A/H1N1/pdm09 constituted 14.6 % cases. Influenza A viruses were detected in co-circulation with influenza B viruses; the latter amounted to 34.1 % of all influenza detections. Other detected causes of influenza-like illness consisted of respiratory syncytial virus (RSV), being predominant, and, sporadically, human coronavirus, parainfluenza 1-3, rhinovirus, and adenovirus. Despite low vaccine effectiveness of solely one component, A/H3N2/, the vaccine could mitigate or shorten the length of influenza infection and reduce the number of severe outcomes and mortality. Thus, vaccination against influenza remains the most effective way to prevent illness and possibly fatal outcomes. PMID:26956457

  20. Epidemic processes in complex networks

    CERN Document Server

    Pastor-Satorras, Romualdo; Van Mieghem, Piet; Vespignani, Alessandro

    2014-01-01

    In recent years the research community has accumulated overwhelming evidence for the emergence of complex and heterogeneous connectivity patterns in a wide range of biological and socio-technical systems. The complex properties of real world networks have a profound impact on the behavior of equilibrium and non-equilibrium phenomena occurring in various systems, and the study of epidemic spreading is central to our understanding of the unfolding of dynamical processes in complex networks. The theoretical analysis of epidemic spreading in heterogeneous networks requires the development of novel analytical frameworks, and it has produced results of conceptual and practical relevance. Here we present a coherent and comprehensive review of the vast research activity concerning epidemic processes, detailing the successful theoretical approaches as well as making their limits and assumptions clear. Physicists, epidemiologists, computer and social scientists share a common interest in studying epidemic spreading and...

  1. Prevention and Control of Seasonal Influenza with Vaccines.

    Science.gov (United States)

    Grohskopf, Lisa A; Sokolow, Leslie Z; Broder, Karen R; Olsen, Sonja J; Karron, Ruth A; Jernigan, Daniel B; Bresee, Joseph S

    2016-01-01

    This report updates the 2015-16 recommendations of the Advisory Committee on Immunization Practices (ACIP) regarding the use of seasonal influenza vaccines (Grohskopf LA, Sokolow LZ, Olsen SJ, Bresee JS, Broder KR, Karron RA. Prevention and control of influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices, United States, 2015-16 influenza season. MMWR Morb Mortal Wkly Rep 2015;64:818-25). Routine annual influenza vaccination is recommended for all persons aged ≥6 months who do not have contraindications. For the 2016-17 influenza season, inactivated influenza vaccines (IIVs) will be available in both trivalent (IIV3) and quadrivalent (IIV4) formulations. Recombinant influenza vaccine (RIV) will be available in a trivalent formulation (RIV3). In light of concerns regarding low effectiveness against influenza A(H1N1)pdm09 in the United States during the 2013-14 and 2015-16 seasons, for the 2016-17 season, ACIP makes the interim recommendation that live attenuated influenza vaccine (LAIV4) should not be used. Vaccine virus strains included in the 2016-17 U.S. trivalent influenza vaccines will be an A/California/7/2009 (H1N1)-like virus, an A/Hong Kong/4801/2014 (H3N2)-like virus, and a B/Brisbane/60/2008-like virus (Victoria lineage). Quadrivalent vaccines will include an additional influenza B virus strain, a B/Phuket/3073/2013-like virus (Yamagata lineage).Recommendations for use of different vaccine types and specific populations are discussed. A licensed, age-appropriate vaccine should be used. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended product is otherwise appropriate. This information is intended for vaccination providers, immunization program personnel, and public health personnel. Information in this report reflects discussions during public meetings of ACIP held on October 21, 2015; February 24, 2016; and June 22, 2016

  2. Prevalence of influenza vaccination and its association with health conditions and risk factors among Kansas adults in 2013: a cross-sectional study

    OpenAIRE

    Santaularia, Jeanie; Hou, Wei; Perveen, Ghazala; Welsh, Ericka; Faseru, Babalola

    2016-01-01

    Background According to the Centers for Disease Control and Prevention, approximately 5-20 % of people are affected by influenza annually, and influenza causes more than 200,000 hospitalizations each year. The purpose of this study is to estimate the prevalence of influenza vaccination among high risk adults in Kansas. Methods The 2013 Kansas BRFSS data (n = 20,712) were analyzed to assess the prevalence of receiving influenza vaccination among Kansas adults, overall and for selected demograp...

  3. 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.

  4. Infection with Possible Precursor of Avian Influenza A(H7N9) Virus in a Child, China, 2013

    OpenAIRE

    Ren, Lili; Yu, Xuelian; Zhao, Baihui; Wu, Fan; Jin, Qi; Zhang, Xi; Wang, Jianwei

    2014-01-01

    During the early stage of the avian influenza A(H7N9) epidemic in China in March 2013, a strain of the virus was identified in a 4-year-old boy with mild influenza symptoms. Phylogenetic analysis indicated that this strain, which has similarity to avian subtype H9N2 viruses, may represent a precursor of more-evolved H7N9 subtypes co-circulating among humans.

  5. Evolutionary Dynamics of Local Pandemic H1N1/2009 Influenza Virus Lineages Revealed by Whole-Genome Analysis

    OpenAIRE

    Baillie, Gregory J.; Galiano, Monica; Agapow, Paul-Michael; Myers, Richard; Chiam, Rachael; Gall, Astrid; Palser, Anne L.; Watson, Simon J.; Hedge, Jessica; Underwood, Anthony; Platt, Steven; McLean, Estelle; Pebody, Richard G.; Rambaut, Andrew; Green, Jonathan

    2012-01-01

    Virus gene sequencing and phylogenetics can be used to study the epidemiological dynamics of rapidly evolving viruses. With complete genome data, it becomes possible to identify and trace individual transmission chains of viruses such as influenza virus during the course of an epidemic. Here we sequenced 153 pandemic influenza H1N1/09 virus genomes from United Kingdom isolates from the first (127 isolates) and second (26 isolates) waves of the 2009 pandemic and used their sequences, dates of ...

  6. EPIDEMIOLOGI TERPADU AVIAN INFLUENZA (FLU BURUNG) BERBASIS TINDAKAN KESEHATAN MASYARAKAT DALAM RESPON PANDEMI INFLUENZA

    OpenAIRE

    Denas Symond

    2009-01-01

    The term surveillance is used in two rather different ways. First, surveillance can mean the continuous security of the factors that determine the occurrence and distribution of disease and other conditions of ill health The second use of the term refers to a special reporting system which is set u for a particularly important health problem or disease, for example the spread of communicable diseases in an epidemic like Avian Influenza (AI) or ( H5N1 ). Such a surveillance system like AI aim ...

  7. Ebola Policies That Hinder Epidemic Response by Limiting Scientific Discourse

    OpenAIRE

    Asgary, Ramin; Julie A Pavlin; Ripp, Jonathan A.; Reithinger, Richard; Polyak, Christina S.

    2015-01-01

    There is an unprecedented epidemic of Ebola virus disease (EVD) in west Africa. There has been a strong response from dedicated health professionals. However, there have also been irrational and fear-based responses that have contributed to misallocation of resources, stigma, and deincentivizing volunteers to combat Ebola at its source. Recently, the State of Louisiana Department of Health and Hospitals issued a ban on those coming from affected countries wishing to attend the annual meetings...

  8. Demographic Variability, Vaccination, and the Spatiotemporal Dynamics of Rotavirus Epidemics

    OpenAIRE

    Pitzer, Virginia E.; Viboud, Cécile; Simonsen, Lone; Steiner, Claudia; Panozzo, Catherine A.; Alonso, Wladimir J.; Miller, Mark A.; Glass, Roger I.; Glasser, John W.; Parashar, Umesh D.; Grenfell, Bryan T.

    2009-01-01

    Historically, annual rotavirus activity in the United States has started in the southwest in late fall and ended in the northeast 3 months later; this trend has diminished in recent years. Traveling waves of infection or local environmental drivers cannot account for these patterns. A transmission model calibrated against epidemiological data shows that spatiotemporal variation in birth rate can explain the timing of rotavirus epidemics. The recent large-scale introduction of rotavirus vaccin...

  9. Spatiotemporal distribution of malaria and the association between its epidemic and climate factors in Hainan, China

    OpenAIRE

    Li Lang; Wang Guangze; Xu Dezhong; Fang Liqun; Wang Shanqing; Long Yong; Xiao Dan; Cao Wuchun; Yan Yongping

    2010-01-01

    Abstract Background Hainan is one of the provinces most severely affected by malaria epidemics in China. The distribution pattern and major determinant climate factors of malaria in this region have remained obscure, making it difficult to target countermeasures for malaria surveillance and control. This study detected the spatiotemporal distribution of malaria and explored the association between malaria epidemics and climate factors in Hainan. Methods The cumulative and annual malaria incid...

  10. 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.

  11. 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.

  12. Monitoring the impact of influenza by age: emergency department fever and respiratory complaint surveillance in New York City.

    Directory of Open Access Journals (Sweden)

    Donald R Olson

    2007-08-01

    Full Text Available BACKGROUND: The importance of understanding age when estimating the impact of influenza on hospitalizations and deaths has been well described, yet existing surveillance systems have not made adequate use of age-specific data. Monitoring influenza-related morbidity using electronic health data may provide timely and detailed insight into the age-specific course, impact and epidemiology of seasonal drift and reassortment epidemic viruses. The purpose of this study was to evaluate the use of emergency department (ED chief complaint data for measuring influenza-attributable morbidity by age and by predominant circulating virus. METHODS AND FINDINGS: We analyzed electronically reported ED fever and respiratory chief complaint and viral surveillance data in New York City (NYC during the 2001-2002 through 2005-2006 influenza seasons, and inferred dominant circulating viruses from national surveillance reports. We estimated influenza-attributable impact as observed visits in excess of a model-predicted baseline during influenza periods, and epidemic timing by threshold and cross correlation. We found excess fever and respiratory ED visits occurred predominantly among school-aged children (8.5 excess ED visits per 1,000 children aged 5-17 y with little or no impact on adults during the early-2002 B/Victoria-lineage epidemic; increased fever and respiratory ED visits among children younger than 5 y during respiratory syncytial virus-predominant periods preceding epidemic influenza; and excess ED visits across all ages during the 2003-2004 (9.2 excess visits per 1,000 population and 2004-2005 (5.2 excess visits per 1,000 population A/H3N2 Fujian-lineage epidemics, with the relative impact shifted within and between seasons from younger to older ages. During each influenza epidemic period in the study, ED visits were increased among school-aged children, and each epidemic peaked among school-aged children before other impacted age groups. CONCLUSIONS

  13. 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

  14. 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/).

  15. Out-of-pocket payments and community-wide health outcomes: an examination of influenza vaccination subsidies in Japan.

    Science.gov (United States)

    Ibuka, Yoko; Bessho, Shun-Ichiro

    2016-07-01

    While studies have shown that reductions in out-of-pocket payments for vaccination generally encourages vaccination uptake, research on the impact on health outcomes has rarely been examined. Thus, the present study, using municipal-level survey data on a subsidy programme for influenza vaccination in Japan that covers the entire country, examines how reductions in out-of-pocket payments for vaccination among non-elderly individuals through a subsidy programme affected regional-level influenza activity. We find that payment reductions are negatively correlated with the number of weeks with a high influenza alert in that region, although the correlation varied across years. At the same time, we find no significant correlation between payment reductions and the total duration of influenza outbreaks (i.e. periods with a moderate or high alert). Given that a greater number of weeks with a high alert indicates a severer epidemic, our findings suggest that reductions in out-of-pocket payments for influenza vaccination among the non-elderly had a positive impact on community-wide health outcomes, indicating that reduced out-of-pocket payments contributes to the effective control of severe influenza epidemics. This suggests that payment reductions could benefit not only individuals by providing them with better access to preventive care, as has been shown previously, but also communities as a whole by shortening the duration of epidemics. PMID:26894514

  16. Contribución del Laboratorio Nacional de Influenza al enfrentamiento de la influenza pandémica 2009 en Cuba Contribution of the National Influenza Laboratory to confront the 2009 pandemic influenza in Cuba

    Directory of Open Access Journals (Sweden)

    Belsy Acosta Herrera

    2011-04-01

    morbidity and mortality around the world. These infections became more significant when associated to epidemics and pandemic events caused by influenza virus. The need for global surveillance of influenza viruses was recognized as early as 1947 and led to the establishment of the World Health Organization (WHO Global Influenza Surveillance Network (GISN. The Cuban National Influenza Centre (NIC belongs to this network since 1975. On April 2009, the recognition of a new influenza A (H1N1 of swine origin circulating in humans was identified as the causative agent of the first pandemic in the 21st century declared by the WHO. OBJECTIVE: to carry out surveillance of the new pandemic virus nationwide. METHODS: the Cuban National Influenza Center developed a diagnostic diagram to confirm infection with the pandemic virus in suspected cases. Different PCR assays for typing and subtyping of influenza A virus were used. RESULTS: from April to December 2009, 6 900 clinical respiratory samples were processed by using this diagram, 980 cases were confirmed and notified to the national health authorities and to the Pan American Health Organization. Human rhinoviruses were other important etiologic agents of the frequently detected acute respiratory infections. CONCLUSION: with the national strategy for surveillance at lab, it was possible to effectively monitor the circulation of the influenza viruses and of other respiratory viruses in our country and to alert the national health authorities, with a view to facing up to the pandemic influenza (2009

  17. Carrying rate and the epidemic characteristics of haemophilus influenzae isolated from healthy children in Zhangjiakou%张家口地区健康儿童呼吸道流感嗜血杆菌带菌现状及DNA多态性分析

    Institute of Scientific and Technical Information of China (English)

    乔海霞; 张彦霞; 常月立; 张玉妥

    2013-01-01

    OBJECTIVE To investigate the infection status,epidemic characteristics and resistance to common antibiotics of haemophilus influenzae (HI) among children subjected to respiratory tract infection of Zhangjiakou city.To provide scientific evidences for preventing,alleviating and controlling HI infection in this region.METHODS HI strains were isolated from throat swabs from healthy children.The antibiotics susceptibility was identified by K-B method,and β-lactamase was ceilnase paper method; isolates were conducted on biological typing,random amplified polymorph DNA (RAPD) was used to identify the genotype and homology of these strains.RESULTS 31 HI strains were isolated from 100 samples of healthy children,positive rate was 31%.All of the 31 HI strains were sensitive to imipenem,chloromycetin,cefaclor,etc.The resistant rate to trimethoprim-sulfamethoxazol and ampicillin were 38.7% and 16.1%,5 strains were β-1actamase positive,accounting for 16.1%.Biotypes Ⅵ and Ⅷ were the prevalent biotypes accounting for 32.4% and 22.6%,respectively.The cluster analysis using RAPD indicated that HI colonizing on healthy children in this city had few cross-infection and there was no obvious central distribution trend.CONCLUSION Compared with the results of ten years ago,it has changed in HI separation rate,biotype and antibiotics resistance.RAPD cluster analysis shows that HI colonizing on healthy children in this city has few cross-infection and there is no obvious central distribution trends.%目的 了解张家口地区健康儿童呼吸道流感嗜血杆菌(Haemophilus infiuenzae,HI)带菌现状、对常用抗生素的耐药情况及流行特征,为预防、控制流感嗜血杆菌感染提供科学依据.方法 从健康儿童咽拭子标本中分离鉴定流感嗜血杆菌,采用K-B法测定其对抗生素的敏感性,用cefinase纸片检测菌株的β-内酰胺酶;对分离菌株进行生物分型,同时用随机扩增多态性DNA (RAPD)技

  18. An innovative influenza vaccination policy: targeting last season's patients.

    Directory of Open Access Journals (Sweden)

    Dan Yamin

    2014-05-01

    Full Text Available Influenza vaccination is the primary approach to prevent influenza annually. WHO/CDC recommendations prioritize vaccinations mainly on the basis of age and co-morbidities, but have never considered influenza infection history of individuals for vaccination targeting. We evaluated such influenza vaccination policies through small-world contact networks simulations. Further, to verify our findings we analyzed, independently, large-scale empirical data of influenza diagnosis from the two largest Health Maintenance Organizations in Israel, together covering more than 74% of the Israeli population. These longitudinal individual-level data include about nine million cases of influenza diagnosed over a decade. Through contact network epidemiology simulations, we found that individuals previously infected with influenza have a disproportionate probability of being highly connected within networks and transmitting to others. Therefore, we showed that prioritizing those previously infected for vaccination would be more effective than a random vaccination policy in reducing infection. The effectiveness of such a policy is robust over a range of epidemiological assumptions, including cross-reactivity between influenza strains conferring partial protection as high as 55%. Empirically, our analysis of the medical records confirms that in every age group, case definition for influenza, clinical diagnosis, and year tested, patients infected in the year prior had a substantially higher risk of becoming infected in the subsequent year. Accordingly, considering individual infection history in targeting and promoting influenza vaccination is predicted to be a highly effective supplement to the current policy. Our approach can also be generalized for other infectious disease, computer viruses, or ecological networks.

  19. 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.

  20. 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

  1. Modeling and predicting seasonal influenza transmission in warm regions using climatological parameters.

    Directory of Open Access Journals (Sweden)

    Radina P Soebiyanto

    Full Text Available BACKGROUND: Influenza transmission is often associated with climatic factors. As the epidemic pattern varies geographically, the roles of climatic factors may not be unique. Previous in vivo studies revealed the direct effect of winter-like humidity on air-borne influenza transmission that dominates in regions with temperate climate, while influenza in the tropics is more effectively transmitted through direct contact. METHODOLOGY/PRINCIPAL FINDINGS: Using time series model, we analyzed the role of climatic factors on the epidemiology of influenza transmission in two regions characterized by warm climate: Hong Kong (China and Maricopa County (Arizona, USA. These two regions have comparable temperature but distinctly different rainfall. Specifically we employed Autoregressive Integrated Moving Average (ARIMA model along with climatic parameters as measured from ground stations and NASA satellites. Our studies showed that including the climatic variables as input series result in models with better performance than the univariate model where the influenza cases depend only on its past values and error signal. The best model for Hong Kong influenza was obtained when Land Surface Temperature (LST, rainfall and relative humidity were included as input series. Meanwhile for Maricopa County we found that including either maximum atmospheric pressure or mean air temperature gave the most improvement in the model performances. CONCLUSIONS/SIGNIFICANCE: Our results showed that including the environmental variables generally increases the prediction capability. Therefore, for countries without advanced influenza surveillance systems, environmental variables can be used for estimating influenza transmission at present and in the near future.

  2. The Analysis of B-Cell Epitopes of Influenza Virus Hemagglutinin.

    Science.gov (United States)

    Shcherbinin, D N; Alekseeva, S V; Shmarov, M M; Smirnov, Yu A; Naroditskiy, B S; Gintsburg, A L

    2016-01-01

    Vaccination has been successfully used to prevent influenza for a long time. Influenza virus hemagglutinin (HA), which induces a humoral immune response in humans and protection against the flu, is the main antigenic component of modern influenza vaccines. However, new seasonal and pandemic influenza virus variants with altered structures of HA occasionally occur. This allows the pathogen to avoid neutralization with antibodies produced in response to previous vaccination. Development of a vaccine with the new variants of HA acting as antigens takes a long time. Therefore, during an epidemic, it is important to have passive immunization agents to prevent and treat influenza, which can be monoclonal or single-domain antibodies with universal specificity (broad-spectrum agents). We considered antibodies to conserved epitopes of influenza virus antigens as universal ones. In this paper, we tried to characterize the main B-cell epitopes of hemagglutinin and analyze our own and literature data on broadly neutralizing antibodies. We conducted a computer analysis of the best known conformational epitopes of influenza virus HAs using materials of different databases. The analysis showed that the core of the HA molecule, whose antibodies demonstrate pronounced heterosubtypic activity, can be used as a target for the search for and development of broad-spectrum antibodies to the influenza virus. PMID:27099781

  3. Taming influenza viruses

    OpenAIRE

    Ozawa, Makoto; Kawaoka, Yoshihiro

    2011-01-01

    Plasmid-based reverse genetics systems allow the artificial generation of viruses with cloned cDNA-derived genomes. Since the establishment of such systems for influenza virus, numerous attempts have been made to tame this pathogenic agent. In particular, several types of viruses expressing foreign genes have been generated and used to further our knowledge of influenza virus replication and pathogenicity and to develop novel influenza vaccines. Here, we review these achievements and discuss ...

  4. Immunobiology of Influenza Vaccines

    OpenAIRE

    Gomez Lorenzo, Margarita M.; Fenton, Matthew J.

    2013-01-01

    Vaccination is the primary strategy for prevention and control of influenza. The surface hemagglutinin (HA) protein of the influenza virus contains two structural elements (head and stalk) that differ in their potential utility as vaccine targets. The head of the HA protein is the primary target of antibodies that confer protective immunity to influenza viruses. The underlying health status, age, and gene polymorphisms of vaccine recipients and, just as importantly, the extent of the antigeni...

  5. Vaccines for Pandemic Influenza

    OpenAIRE

    Luke, Catherine J.; Subbarao, Kanta

    2006-01-01

    Recent outbreaks of highly pathogenic avian influenza in Asia and associated human infections have led to a heightened level of awareness and preparation for a possible influenza pandemic. Vaccination is the best option by which spread of a pandemic virus could be prevented and severity of disease reduced. Production of live attenuated and inactivated vaccine seed viruses against avian influenza viruses, which have the potential to cause pandemics, and their testing in preclinical studies and...

  6. Filamentous influenza viruses

    OpenAIRE

    Dadonaite, Bernadeta; Vijyakrishnan, Swetha; Fodor, Ervin; Bhella, David; Hutchinson, Edward C.

    2016-01-01

    Clinical isolates of influenza virus produce pleomorphic virus particles, including extremely long filamentous virions. In contrast, strains of influenza that have adapted to laboratory growth typically produce only spherical virions. As a result, the filamentous phenotype has been overlooked in most influenza virus research. Recent advances in imaging and improved animal models have highlighted the distinct structure and functional relevance of filamentous virions. In this review we summaris...

  7. Towards universal influenza vaccines?

    OpenAIRE

    Osterhaus, Ab; Fouchier, Ron; Rimmelzwaan, Guus

    2011-01-01

    Vaccination 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 development and production of pandemic influenza vaccines are response time and production capacity as well as vaccine efficacy and safety. Several improvements can be envisaged. Vaccine production technologi...

  8. New treatments for influenza

    OpenAIRE

    Barik Sailen

    2012-01-01

    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 st...

  9. 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.

  10. Epidemic processes in complex networks

    Science.gov (United States)

    Pastor-Satorras, Romualdo; Castellano, Claudio; Van Mieghem, Piet; Vespignani, Alessandro

    2015-07-01

    In recent years the research community has accumulated overwhelming evidence for the emergence of complex and heterogeneous connectivity patterns in a wide range of biological and sociotechnical systems. The complex properties of real-world networks have a profound impact on the behavior of equilibrium and nonequilibrium phenomena occurring in various systems, and the study of epidemic spreading is central to our understanding of the unfolding of dynamical processes in complex networks. The theoretical analysis of epidemic spreading in heterogeneous networks requires the development of novel analytical frameworks, and it has produced results of conceptual and practical relevance. A coherent and comprehensive review of the vast research activity concerning epidemic processes is presented, detailing the successful theoretical approaches as well as making their limits and assumptions clear. Physicists, mathematicians, epidemiologists, computer, and social scientists share a common interest in studying epidemic spreading and rely on similar models for the description of the diffusion of pathogens, knowledge, and innovation. For this reason, while focusing on the main results and the paradigmatic models in infectious disease modeling, the major results concerning generalized social contagion processes are also presented. Finally, the research activity at the forefront in the study of epidemic spreading in coevolving, coupled, and time-varying networks is reported.

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

    OpenAIRE

    Dyah Ayu Hewajuli; Ni Luh Putu Indi Dharmiayanti

    2012-01-01

    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 ...

  12. Influenza-Sediment Interactions

    Science.gov (United States)

    Trusiak, A.; Block, K. A.; Katz, A.; Gottlieb, P.; Alimova, A.; Galarza, J.; Wei, H.; Steiner, J. C.

    2013-12-01

    A typical water fowl can secrete 1012 influenza virions per day. Therefore it is not unexpected that influenza virions interact with sediments in the water column. The influence of sediments on avian influenza virions is not known. With the threat of avian influenza emerging into the human population, it is crucial to understand virus survivability and residence time in a body of water. Influenza and clay sediments are colloidal particles and thus aggregate as explained by DLVO (Derjaguin & Landau, Verwey & Overbeek) theory. Of great importance is an understanding of the types of particulate or macromolecular components that bind the virus particles, and whether the virus remains biologically active. We present results of hetero-aggregation and transmission electron microscopy experiments performed with influenza A/PR8/38. Influenza particles are suspended with sediment and minimal nutrients for several days, after which the components are evaluated to determine influenza concentration and survivability. Transmission electron microscopy results are reported on the influenza-sediment aggregates to elucidate structure and morphology of the components.

  13. 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. PMID:27426005

  14. Epidemiology of Haemophilus influenzae bacteremia: A multi-national population-based assessment

    DEFF Research Database (Denmark)

    Laupland, Kevin B; Schønheyder, Henrik C; Østergaard, Christian;

    2011-01-01

    OBJECTIVES: Haemophilus influenzae is an important cause of invasive infection but contemporary data in non-selected populations is limited. METHODS: Population-based surveillance for Haemophilus influenzae bacteremia was conducted in seven regions in Australia, Canada, and Denmark during 2000......-2008. RESULTS: The overall annual incidence rate was 1.31 per 100,000 population and type specific rates were 0.08 for H. influenzae serotype b (Hib), 0.22 for H. influenzae serotypes a, c-f (Hiac-f), and 0.98 per 100,000 for non-typeable H. influenzae (NTHi). Very young and old patients were at highest risk......%. Factors independently associated with death at 30-days in logistic regression analysis included male gender, hospital-onset disease, older age, and lower respiratory tract, central nervous system, or unknown focus of infection. CONCLUSIONS: Haemophilus influenzae is an important cause of morbidity and...

  15. 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

    2015-06-01

    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

  16. 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...

  17. Informing the Front Line about Common Respiratory Viral Epidemics

    Science.gov (United States)

    Gesteland, Per H; Samore, Matthew H; Pavia, Andrew T; Srivastava, Rajendu; Korgenski, Kent; Gerber, Kristine; Daly, Judy A; Mundorff, Michael B; Rolfs, Robert T; James, Brent C.; Byington, Carrie L.

    2007-01-01

    The nature of clinical medicine is to focus on individuals rather than the populations from which they originate. This orientation can be problematic in the context of acute healthcare delivery during routine winter outbreaks of viral respiratory disease where an individual’s likelihood of viral infection depends on knowledge of local disease incidence. The level of interest in and perceived utility of community and regional infection data for front line clinicians providing acute care is unclear. Based on input from clinicians, we developed an automated analysis and reporting system that delivers pathogen-specific epidemic curves derived from a viral panel that tests for influenza, RSV, adenovirus, parainfluenza and human metapneumovirus. Surveillance summaries were actively e-mailed to clinicians practicing in emergency, urgent and primary care settings and posted on a web site for passive consumption. We demonstrated the feasibility and sustainability of a system that provides both timely and clinically useful surveillance information. PMID:18693841

  18. 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...

  19. Influenza Vaccination Coverage Among Health Care Personnel--United States, 2014-15 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; Bridges, Carolyn B; DiSogra, Charles; Sokolowski, John; Walker, Deborah K; Greby, Stacie M

    2015-09-18

    The Advisory Committee on Immunization Practices recommends annual influenza vaccination for all health care personnel (HCP) to reduce influenza-related morbidity and mortality among both HCP and their patients and to decrease absenteeism among HCP. To estimate influenza vaccination coverage among U.S. HCP for the 2014–15 influenza season, CDC conducted an opt-in Internet panel survey of 1,914 HCP during March 31–April 15, 2015. Overall, 77.3% of HCP survey participants reported receiving an influenza vaccination during the 2014–15 season, similar to the 75.2% coverage among HCP reported for the 2013–14 season. Vaccination coverage was highest among HCP working in hospitals (90.4%) and lowest among HCP working in long-term care (LTC) settings (63.9%). By occupation, coverage was highest among pharmacists (95.3%) and lowest among assistants and aides (64.4%). Influenza vaccination coverage was highest among HCP who were required by their employer to be vaccinated (96.0%). Among HCP without an employer requirement for vaccination, coverage was higher for HCP working in settings where vaccination was offered on-site at no cost for 1 day (73.6%) or multiple days (83.9%) and lowest among HCP working in settings where vaccine was neither required, promoted, nor offered on-site (44.0%). Comprehensive vaccination strategies that include making vaccine available at no cost at the workplace along with active promotion of vaccination might help increase vaccination coverage among HCP and reduce the risk for influenza to HCP and their patients. PMID:26389743

  20. 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.

  1. OBESITY: OVERVIEW OF AN EPIDEMIC

    OpenAIRE

    Mitchell, Nia; Catenacci, Vicki; Wyatt, Holly R.; Hill, James O.

    2011-01-01

    Despite growing recognition of the problem, the obesity epidemic continues in the U.S., and obesity rates are increasing around the world. The latest estimates are that approximately 34% of adults and 15–20% of children and adolescents in the U.S. are obese. Obesity affects every segment of the U.S. population. Obesity increases the risk of many chronic diseases in children and adults. The epidemic of obesity arose gradually over time, apparently from a small, consistent degree of positive en...

  2. INFLUENZA VACCINATION UPTAKE AMONG HEALTHCARE WORKERS AT A MALAYSIAN TEACHING HOSPITAL.

    Science.gov (United States)

    Rashid, Zetti Zainol; Jasme, Humaira; Liang, Ho Jing; Yusof, Mardiyah Mohd; Sharani, Zatil Zahidah Mohd; Mohamad, Marlyn; Ismail, Zalina; Sulong, Anita; Jalil, Nordiah Awang

    2015-03-01

    Annual influenza vaccination is the most important preventive strategy against influenza illness in healthcare workers (HCWs), who could acquire influenza from and transmit influenza to patients and other HCWs. Despite the well established benefits and strong recommendations for influenza vaccination for all HCWs, influenza vaccination uptake at the Universiti Kebangsaan Malaysia Medical Centre (UKMMC) for the past 3 years has been low and is decreasing. We aimed to determine the factors associated with influenza vaccination uptake among HCWs at UKMMC. We conducted a cross sectional study via questionnaire among 211 randomly selected HCWs, consisting of 106 HCWs who were vaccinated in 2011 and 105 HCWs who were not vaccinated in 2010 or 2011. We had a 100% response rate. Influenza vaccination uptake was significantly associated with age and previous vaccination history, with older HCWs being more likely to be vaccinated (adjusted OR = 12.494; 95% CI:6.278-24.863; p Publicity at the workplace was the main source of information about the vaccine (51.2% of respondents), followed by colleagues (29.9%). Despite the low uptake, 85.3% of respondents believed influenza vaccination was important for disease prevention. The most common reason given for vaccination was protection against influenza infection (73.6%). The most common reason for not having the vaccine was time constraints (56.2%). An evidenced-based strategy needs to be developed to improve vaccine uptake or having mandatory vaccination. PMID:26513924

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

    Science.gov (United States)

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

    2016-01-01

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

  4. 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.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  6. INFLUENZA VIRUS IN POULTRY

    Science.gov (United States)

    Avian influenza virus (AIV) is normally found in wild birds, particularly in ducks and shorebirds, where it does not cause any perceptible clinical disease. However, poultry, including chickens and turkeys, are not normal hosts for avian influenza, but if the virus is introduced it can result in mi...

  7. National Pandemic Influenza Plan

    OpenAIRE

    Department of Health

    2007-01-01

    National Pandemic Influenza Plan The purpose of this document is to tell you about pandemic influenza (flu), to explain what the Government and the health services are doing to prepare for a possible pandemic and most importantly, to advise you what you need to do if there is a pandemic. Click here to download PDF 614kb

  8. Haemophilus Influenzae Type b

    Science.gov (United States)

    ... Issues Listen Español Text Size Email Print Share Haemophilus Influenzae type b Page Content Article Body If you’re like many parents, you may have been unfamiliar with Haemophilus influenzae type b (Hib) infections until your pediatrician recommended a vaccine ...

  9. Analysis of influenza epidemiological characteristics in Chaozhou, Guangdong province, 2013%2013年广东省潮州市流行性感冒流行特征分析

    Institute of Scientific and Technical Information of China (English)

    苏雪銮; 谢璧珠; 陈爱苗; 杨惠钿; 林敏

    2014-01-01

    目的:了解广东省潮州市2013年度流行性感冒流行特征及病毒流行株构成。方法采集监测哨点医院疑似流感样患者咽拭子标本,采用实时荧光 PCR(real-time RT-PCR)检测病毒核酸。结果全市流感检测哨点医院共采集标本830份,流感病毒核酸阳性为53份,阳性率为6.39%;其中新甲型 H1N1流感占49.06%(26/53)、乙型流感病毒占28.30%(15/53)、季节性流感病毒 H3亚型占22.64%(12/53),未分离到季节性流感病毒H1。4月和12月为年度病毒检测高峰。病毒感染率以5~14岁组(14.12%)最高,与其它组比较存在统计学差异(P <0.05)。结论2013年度潮州市流感病毒优势株为新型甲型H1N1,全年有2个流行高峰,在4月和12月,主要发病人群为学龄前儿童和小学生。%Objective To analyze the epidemiological characteristics of influenza and the composition of epidemic strains in Chaozhou, Guangdong province, 2013. Methods Throat swabs were collected from influenza-like patients in influenza-monitoring hospitals and real-time RT-PCR was used to detect influenza viruses in these samples. Results 53 strains of influenza viruses were detected from the 830 throat swabs (6.39%), including 26 strains of novel influenza A (H1N1) viruses (49.06%, 26/53), 15 strains of B influenza virus (28.30%, 15/53) and 12 strains of H3 subtype influenza virus (22.64%, 12/53). None of H1 subtype influenza virus was isolated from these samples. The annual peaks of virus detection were in April and December. The highest virus prevalence (14.12%) was observed in 5 ~ 14 years old group and statistical difference was found between it and other groups (P < 0.05). Conclusion The predominant influenza virus detected in Chaozhou in 2013 was H1N1 virus. Two prevalent peaks of influenza viruses were in April and December and the infections mainly occurred among pre-school children and pupils.

  10. Protective efficacy of a bacterially produced modular capsomere presenting M2e from influenza: extending the potential of broadly cross-protecting epitopes.

    Science.gov (United States)

    Wibowo, Nani; Hughes, Fiona K; Fairmaid, Emily J; Lua, Linda H L; Brown, Lorena E; Middelberg, Anton P J

    2014-06-17

    Influenza A viruses drift and shift, emerging as antigenically distinct strains that lead to epidemics and pandemics of varying severity. Even epitopes associated with broad cross-protection against different strains, such as the ectodomain of matrix protein 2 (M2e), mutate unpredictably. Vaccine protective efficacy is only ensured when the emerging virus lies within the vaccine's cross-protective domain, which is poorly defined in most situations. When virus emerges outside this domain it is essential to rapidly re-engineer the vaccine and hence re-center the cross-protective domain on the new virus. This approach of vaccine re-engineering in response to virus change is the cornerstone of the current influenza control system, based on annual prediction and/or pandemic reaction. This system could become more responsive, and perhaps preventative, if its speed could be improved. Here, we demonstrate vaccine efficacy of a rapidly manufacturable modular capsomere presenting the broadly cross-protecting M2e epitope from influenza. M2e inserted into a viral capsomere at the DNA level was expressed in Escherichia coli as a fusion protein (Wibowo et al., 2013). Immunization of mice with this modular capsomere adjuvanted with conventional aluminum hydroxide induced high (more than 10(5) endpoint titer) levels of M2e-specific antibodies that reduced disease severity and viral load in the lungs of challenged mice. The combination of rapid manufacturability of modular capsomere presented in this study, and the established cross-protective efficacy of M2e, allow rapid matching of vaccine to the circulating virus and hence rapid re-centering of the vaccine's cross-protective domain onto the virus. This approach synergizes the discussed benefits of broadly cross-protecting epitopes with rapid scale-up vaccine manufacture using microbial cell factories. PMID:24795225

  11. 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.

  12. Combination Chemotherapy for Influenza

    Directory of Open Access Journals (Sweden)

    Robert G. Webster

    2010-07-01

    Full Text Available The emergence of pandemic H1N1 influenza viruses in April 2009 and the continuous evolution of highly pathogenic H5N1 influenza viruses underscore the urgency of novel approaches to chemotherapy for human influenza infection. Anti-influenza drugs are currently limited to the neuraminidase inhibitors (oseltamivir and zanamivir and to M2 ion channel blockers (amantadine and rimantadine, although resistance to the latter class develops rapidly. Potential targets for the development of new anti-influenza agents include the viral polymerase (and endonuclease, the hemagglutinin, and the non-structural protein NS1. The limitations of monotherapy and the emergence of drug-resistant variants make combination chemotherapy the logical therapeutic option. Here we review the experimental data on combination chemotherapy with currently available agents and the development of new agents and therapy targets.

  13. Epidemics on random graphs with tunable clustering

    OpenAIRE

    Britton, Tom; Deijfen, Maria; Lagerås, Andreas Nordvall; Lindholm, Mathias

    2008-01-01

    In this paper, a branching process approximation for the spread of a Reed-Frost epidemic on a network with tunable clustering is derived. The approximation gives rise to expressions for the epidemic threshold and the probability of a large outbreak in the epidemic. It is investigated how these quantities varies with the clustering in the graph and it turns out for instance that, as the clustering increases, the epidemic threshold decreases. The network is modelled by a random intersection gra...

  14. Dengue 3 Epidemic, Havana, 2001

    OpenAIRE

    Peláez, Otto; Guzmán, María G.; Kourí, Gustavo; Pérez, Raúl; San Martín, José L.; Vázquez, Susana; Rosario, Delfina; Mora, Regla; Quintana, Ibrahim; Bisset, Juan; Cancio, Reynel; Masa, Ana M; Castro, Osvaldo; González, Daniel; Avila, Luis C.

    2004-01-01

    In June 2001, dengue transmission was detected in Havana, Cuba; 12,889 cases were reported. Dengue 3, the etiologic agent of the epidemic, caused the dengue hemorrhagic fever only in adults, with 78 cases and 3 deaths. After intensive vector control efforts, no new cases have been detected.

  15. 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.

  16. 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.

  17. 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...

  18. Detection of influenza vaccine effectiveness among nursery school children: Lesson from a season with cocirculating respiratory syncytial virus.

    Science.gov (United States)

    Nakata, Keiko; Fujieda, Megumi; Miki, Hitoshi; Fukushima, Wakaba; Ohfuji, Satoko; Maeda, Akiko; Kase, Tetsuo; Hirota, Yoshio

    2015-01-01

    In the winter influenza epidemic season, patients with respiratory illnesses including respiratory syncytial virus (RSV) infections increase among young children. Therefore, we evaluated the effectiveness of influenza vaccine against influenza-like illness (ILI) using a technique to identify outbreaks of RSV infection and to distinguish those patients from ILI patients. The study subjects were 101 children aged 12 to 84 months attending nursery school. We classified the cases into 6 levels based on the definitions of ILI for outcomes. We established observation periods according to information obtained from regional surveillance and rapid diagnostic tests among children. Multivariate odds ratios (ORs) for each case classification were obtained using a logistic regression model for each observation period. For the entire observation period, ORs for cases with fever plus respiratory symptoms were reduced marginally significantly. For the local influenza epidemic period, only the OR for the most serious cases was significantly decreased (0.20 [95%CI: 0.04-0.94]). During the influenza outbreak among the nursery school children, multivariate ORs for fever plus respiratory symptoms decreased significantly (≥ 38.0°C plus ≥ one symptoms: 0.23 [0.06-0.91), ≥ 38.0°C plus ≥ 2 symptoms: 0.21 [0.05-0.85], ≥ 39.0°C plus ≥ one symptoms: 0.18 [0.04-0.93] and ≥ 39.0°C plus ≥ 2 symptoms: 0.16 [0.03-0.87]). These results suggest that confining observation to the peak influenza epidemic period and adoption of a strict case classification system can minimize outcome misclassification when evaluating the effectiveness of influenza vaccine against ILI, even if influenza and RSV cocirculate in the same season. PMID:25714791

  19. 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.

  20. Epidemics spreading in interconnected complex networks

    International Nuclear Information System (INIS)

    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.

  1. 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

  2. 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

  3. Influenza viral infections among the Iranian Hajj pilgrims returning to Shiraz, Fars province, Iran

    Science.gov (United States)

    Moattari, Afagh; Emami, Amir; Moghadami, Mohsen; Honarvar, Behnam

    2012-01-01

    Please cite this paper as: Moattari et al. (2012) Influenza viral infections among the Iranian Hajj pilgrims returning to Shiraz, Fars province, Iran. Influenza and Other Respiratory Viruses 6(601), e77–e79 Background  Annually over two million Muslims from across the world converge on Mecca to perform the Hajj pilgrimage. Overcrowding at the Hajj facilitates spread of communicable diseases, especially respiratory infections. The aim of this study was to determine the attack rate of seasonal and pandemic influenza among returning Iranian pilgrims after the 2009 Hajj. Methods  Clinical data and throat swabs were collected at Shiraz airport from symptomatic Iranian pilgrims of Fars province who were returning from the Hajj between 15 and 21 December 2009. The specimens were tested at the Shiraz University of Medical Sciences Influenza Research Center for influenza viruses by cell culture and real‐time reverse transcriptase polymerase chain reaction (RTrtPCR) according to standard protocol. Findings  Out of 3000 pilgrims from Fars province who attended the Hajj 2009, 275 symptomatic pilgrims were recruited into this study. Pilgrims had fever, cough, muscle ache and sore throat in various combinations. Twenty‐five (9·1%) pilgrims had influenza by virus culture and these were as follows: influenza B (n = 17), influenza A H3N2 (n = 8) and pandemic H1N1 (n = 5), whereas 33 (12%) had influenza by RTrtPCR: influenza B (n = 20), influenza A H3N2 (n = 8) and pandemic H1N1 (n = 5). Interpretation  Both seasonal and pandemic influenza infections occurred among the Iranian Hajj pilgrims; seasonal viruses were more common than the pandemic viruses even though all pilgrims were vaccinated against seasonal influenza. PMID:22606996

  4. Acute infectious diseases and immunologic responses. Some stories from clinical practice apropos the Influenza A (H1N1) pandemic

    OpenAIRE

    Alfredo Darío Espinosa Brito

    2011-01-01

    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.

  5. 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.

  6. The Scourge of Asian Flu: In Utero Exposure to Pandemic Influenza and the Development of a Cohort of British Children

    Science.gov (United States)

    Kelly, Elaine

    2011-01-01

    This paper examines the impact of in utero exposure to the Asian influenza pandemic of 1957 upon childhood development. Outcome data are provided by the National Child Development Study (NCDS), a panel study where all members were potentially exposed in the womb. Epidemic effects are identified using geographic variation in a surrogate measure of…

  7. 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.

  8. Risk maps for the spread of highly pathogenic avian influenza in poultry.

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    Gert Jan Boender

    2007-04-01

    Full Text Available Devastating epidemics of highly contagious animal diseases such as avian influenza, classical swine fever, and foot-and-mouth disease underline the need for improved understanding of the factors promoting the spread of these pathogens. Here the authors present a spatial analysis of the between-farm transmission of a highly pathogenic H7N7 avian influenza virus that caused a large epidemic in The Netherlands in 2003. The authors developed a method to estimate key parameters determining the spread of highly transmissible animal diseases between farms based on outbreak data. The method allows for the identification of high-risk areas for propagating spread in an epidemiologically underpinned manner. A central concept is the transmission kernel, which determines the probability of pathogen transmission from infected to uninfected farms as a function of interfarm distance. The authors show how an estimate of the transmission kernel naturally provides estimates of the critical farm density and local reproduction numbers, which allows one to evaluate the effectiveness of control strategies. For avian influenza, the analyses show that there are two poultry-dense areas in The Netherlands where epidemic spread is possible, and in which local control measures are unlikely to be able to halt an unfolding epidemic. In these regions an epidemic can only be brought to an end by the depletion of susceptible farms by infection or massive culling. The analyses provide an estimate of the spatial range over which highly pathogenic avian influenza viruses spread between farms, and emphasize that control measures aimed at controlling such outbreaks need to take into account the local density of farms.

  9. Demographic variability, vaccination, and the spatiotemporal dynamics of rotavirus epidemics.

    Science.gov (United States)

    Pitzer, Virginia E; Viboud, Cécile; Simonsen, Lone; Steiner, Claudia; Panozzo, Catherine A; Alonso, Wladimir J; Miller, Mark A; Glass, Roger I; Glasser, John W; Parashar, Umesh D; Grenfell, Bryan T

    2009-07-17

    Historically, annual rotavirus activity in the United States has started in the southwest in late fall and ended in the northeast 3 months later; this trend has diminished in recent years. Traveling waves of infection or local environmental drivers cannot account for these patterns. A transmission model calibrated against epidemiological data shows that spatiotemporal variation in birth rate can explain the timing of rotavirus epidemics. The recent large-scale introduction of rotavirus vaccination provides a natural experiment to further test the impact of susceptible recruitment on disease dynamics. The model predicts a pattern of reduced and lagged epidemics postvaccination, closely matching the observed dynamics. Armed with this validated model, we explore the relative importance of direct and indirect protection, a key issue in determining the worldwide benefits of vaccination. PMID:19608910

  10. 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

  11. Some Observations on Naso-pharyngeal Epidemics in Public Schools.

    Science.gov (United States)

    Glover, J A

    1928-07-01

    Over 80 per cent. of school sickness, whether judged by the number of cases or by the time lost, is transmitted by "droplet" infection.The alleged increase in sickness in public schools is partly apparent, due to increased attention to minor febricula and partly real, due (1) to increased influenza prevalence, the aftermath of the great epidemic of 1918, and (2) to the increased demand for public school education leading to pressure upon accommodation, and especially to overcrowding in dormitories.The bulk of the droplet infections are accounted for by (1) influenza; (2) feverish cold, chill, or P.U.O.; (3) tonsillitis; regular infectious diseases make a comparatively small showing. The incidence and bacteriological findings and the variations in the incidence of pneumonia and otitis media are discussed. Are these complications really secondary epidemics? Tonsillitis, bacteriological findings, milk.Prophylaxis.-Efficacy of vaccines uncertain. Some evidence that they may diminish the onset of complications. If given vaccines should be administered before the danger period, i.e., not later than November.Intensive prophylaxia other than vaccines during the first half of the Lent term would probably amply repay any trouble. It should include:-(a) Special efforts to prevent boys returning to school after the Christmas holidays infected with influenza or febricula.(b) Temperature taking for three weeks.(c) Immediate isolation of all pyrexias and catarrhs.(d) No work before breakfast for at least the first six weeks of the term.(e) All hot baths and showers taken during the day or after games to be followed by cold showers.(f) Prevention of chill in watching games, etc.(g) Increased provision for drying clothes, uniforms and boots.Infection mainly takes place in sleeping quarters, and proper spacing out of beds and thorough "cross" ventilation in dormitories is of paramount importance; instances of cross infection due to proximity of beds; illustrated by bed charts and

  12. Synthesis and characterization of antigenic influenza A M2e protein peptide-poly(acrylic) acid bioconjugate and determination of toxicity in vitro

    OpenAIRE

    Kilinc, Yasemin Budama; Akdeste, Zeynep Mustafaeva; Koc, Rabia Cakir; Bagirova, Melahat; Allahverdiyev, Adil

    2014-01-01

    The influenza A virus is a critical public health problem that causes epidemics and pandemics, and occurs widely all over the world. Various vaccines against the virus have not provided a solution to the problem. Different approaches, particularly M2e peptide–based vaccines, are available for developing universal vaccines against influenza A. However, it is important to select a suitable carrier to obtain an effective vaccine. Accordingly, studies on the usage of various carriers are ongoing....

  13. Estimating infection attack rates and severity in real time during an influenza pandemic: Analysis of serial cross-sectional serologic surveillance data

    OpenAIRE

    Wu, Joseph T.; Ho, Andrew; Ma, Edward S.K.; Lee, Cheuk Kwong; Daniel K W Chu; Ho, Po-Lai; Hung, Ivan F. N.; Ho, Lai Ming; Lin, Che Kit; Tsang, Thomas; Lo, Su-Vui; Lau, Yu-Lung; Leung, Gabriel M; Cowling, Benjamin J; Peiris, J.S. Malik

    2011-01-01

    Editors' Summary Background Every winter, millions of people catch influenza—a viral infection of the airways—and about half a million die as a result. These seasonal epidemics occur because small but frequent changes in the influenza virus mean that the immune response produced by infection with one year's virus provides only partial protection against the next year's virus. Occasionally, however, a very different influenza virus emerges to which people have virtually no immunity. Such virus...

  14. Influenza in outpatient ILI case-patients in national hospital-based surveillance, Bangladesh, 2007-2008.

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    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.

  15. 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

  16. Evaluation of Wondfo influenza A&B fast test based on immunochromatography assay for rapid diagnosis of influenza A H1N1

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    Yunping Peng

    2013-04-01

    Full Text Available Influenza viruses cause significant morbidity and mortality in both children and adults during local outbreaks or epidemics. Therefore, a rapid test for influenza A&B would be useful. This study was conducted to evaluate the clinical performance of the Wondfo influenza A&B test for rapid diagnosis of influenza A H1N1 Infection. The rapid testing assay could distinguish infection of influenza A and B virus. The reference viral strains were cultured in MDCK cells while TCID50 if the viruses were determined. The analytical sensitivity of the Wondfo kit was 100 TCID50/ml. The Wondfo kit did not show cross reactivity with other common viruses. 1928 suspected cases of influenza A (H1N1 virus infection were analyzed in the Wondfo influenza A&B test and other commercially available products. Inconsistent results were further confirmed by virus isolation in cell culture. The sensitivity, specificity, positive predictive value (PPV and negative predictive value (NPV were 100%, 98.23%, 92.45%, and 100% for flu A, and 96.39%, 99.95%, 98.77%, and 99.84% for flu B respectively. 766 suspected cases of influenza A (H1N1 virus infection were analyzed in the Wondfo influenza A&B test and RT-PCR. The sensitivity, specificity, PPV and NPV were 56.5%, 99.75%, 99.52% and 71.04% for flu A, 25.45%, 99.86%, 93.33% and 94.54% for flu B respectively. These results indicate that the Wondfo influenza A&B test has high positive and negative detection rates. One hundred fifty-six specimens of influenza A (H1N1 confirmed by RT-PCR were analyzed by the Wondfo influenza A&B test and 66.67% were positive while only 18.59% were positive by the reference kit. These results indicate that our rapid diagnostic assay may be useful for analyzing influenza A H1N1 infections in patient specimen.

  17. 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.

  18. Multiple routes transmitted epidemics on multiplex networks

    International Nuclear Information System (INIS)

    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.

  19. The feasibility of age-specific travel restrictions during influenza pandemics

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    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

  20. The role of cellular immunity in Influenza H1N1 population dynamics

    OpenAIRE

    Duvvuri Venkata R; Heffernan Jane M; Moghadas Seyed M; Duvvuri Bhargavi; Guo Hongbin; Fisman David N; Wu Jianhong; Wu Gillian E

    2012-01-01

    Abstract Background Pre-existing cellular immunity has been recognized as one of the key factors in determining the outcome of influenza infection by reducing the likelihood of clinical disease and mitigates illness. Whether, and to what extent, the effect of this self-protective mechanism can be captured in the population dynamics of an influenza epidemic has not been addressed. Methods We applied previous findings regarding T-cell cross-reactivity between the 2009 pandemic H1N1 strain and s...

  1. 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.

  2. Forecasting the 2013-2014 influenza season using Wikipedia.

    Science.gov (United States)

    Hickmann, Kyle S; Fairchild, Geoffrey; Priedhorsky, Reid; Generous, Nicholas; Hyman, James M; Deshpande, Alina; Del Valle, Sara Y

    2015-05-01

    Infectious diseases are one of the leading causes of morbidity and mortality around the world; thus, forecasting their impact is crucial for planning an effective response strategy. According to the Centers for Disease Control and Prevention (CDC), seasonal influenza affects 5% to 20% of the U.S. population and causes major economic impacts resulting from hospitalization and absenteeism. Understanding influenza dynamics and forecasting its impact is fundamental for developing prevention and mitigation strategies. We combine modern data assimilation methods with Wikipedia access logs and CDC influenza-like illness (ILI) reports to create a weekly forecast for seasonal influenza. The methods are applied to the 2013-2014 influenza season but are sufficiently general to forecast any disease outbreak, given incidence or case count data. We adjust the initialization and parametrization of a disease model and show that this allows us to determine systematic model bias. In addition, we provide a way to determine where the model diverges from observation and evaluate forecast accuracy. Wikipedia article access logs are shown to be highly correlated with historical ILI records and allow for accurate prediction of ILI data several weeks before it becomes available. The results show that prior to the peak of the flu season, our forecasting method produced 50% and 95% credible intervals for the 2013-2014 ILI observations that contained the actual observations for most weeks in the forecast. However, since our model does not account for re-infection or multiple strains of influenza, the tail of the epidemic is not predicted well after the peak of flu season has passed. PMID:25974758

  3. Forecasting the 2013-2014 influenza season using Wikipedia.

    Directory of Open Access Journals (Sweden)

    Kyle S Hickmann

    2015-05-01

    Full Text Available Infectious diseases are one of the leading causes of morbidity and mortality around the world; thus, forecasting their impact is crucial for planning an effective response strategy. According to the Centers for Disease Control and Prevention (CDC, seasonal influenza affects 5% to 20% of the U.S. population and causes major economic impacts resulting from hospitalization and absenteeism. Understanding influenza dynamics and forecasting its impact is fundamental for developing prevention and mitigation strategies. We combine modern data assimilation methods with Wikipedia access logs and CDC influenza-like illness (ILI reports to create a weekly forecast for seasonal influenza. The methods are applied to the 2013-2014 influenza season but are sufficiently general to forecast any disease outbreak, given incidence or case count data. We adjust the initialization and parametrization of a disease model and show that this allows us to determine systematic model bias. In addition, we provide a way to determine where the model diverges from observation and evaluate forecast accuracy. Wikipedia article access logs are shown to be highly correlated with historical ILI records and allow for accurate prediction of ILI data several weeks before it becomes available. The results show that prior to the peak of the flu season, our forecasting method produced 50% and 95% credible intervals for the 2013-2014 ILI observations that contained the actual observations for most weeks in the forecast. However, since our model does not account for re-infection or multiple strains of influenza, the tail of the epidemic is not predicted well after the peak of flu season has passed.

  4. Knowledge, attitudes, and practices of Hong Kong population towards human A/H7N9 influenza pandemic preparedness, China, 2014

    OpenAIRE

    Chan, Emily YY; Cheng, Calvin KY; Tam, Greta; Huang, Zhe; Lee, Poyi

    2015-01-01

    Background Since SARS epidemic in 2003, Hong Kong has experienced several major epidemic risks, but how general community might react to the repeated infectious diseases health risks have not been studied. In 2013, imported human H7N9 influenza infected cases from China were reported. Our study aims to assess the knowledge, attitude and practice (KAP) concerning A/H7N9 among Hong Kong general population regarding pandemic preparedness in early 2014. Methods A cross-sectional, population-based...

  5. 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

  6. Revised estimates of influenza-associated excess mortality, United States, 1995 through 2005

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    Hossain Md Monir

    2008-12-01

    Full Text Available Abstract Background Excess mortality due to seasonal influenza is thought to be substantial. However, influenza may often not be recognized as cause of death. Imputation methods are therefore required to assess the public health impact of influenza. The purpose of this study was to obtain estimates of monthly excess mortality due to influenza that are based on an epidemiologically meaningful model. Methods and Results U.S. monthly all-cause mortality, 1995 through 2005, was hierarchically modeled as Poisson variable with a mean that linearly depends both on seasonal covariates and on influenza-certified mortality. It also allowed for overdispersion to account for extra variation that is not captured by the Poisson error. The coefficient associated with influenza-certified mortality was interpreted as ratio of total influenza mortality to influenza-certified mortality. Separate models were fitted for four age categories ( Conclusion Annual estimates for influenza mortality were highly variable from year to year, but they were systematically lower than previously published estimates. The excellent fit of our model with the data suggest validity of our estimates.

  7. Fluctuating epidemics on adaptive networks

    CERN Document Server

    Shaw, Leah B

    2008-01-01

    A model for epidemics on an adaptive network is considered. Nodes follow an SIRS (susceptible-infective-recovered-susceptible) pattern. Connections are rewired to break links from non-infected nodes to infected nodes and are reformed to connect to other non-infected nodes, as the nodes that are not infected try to avoid the infection. Monte Carlo simulation and numerical solution of a mean field model are employed. The introduction of rewiring affects both the network structure and the epidemic dynamics. Degree distributions are altered, and the average distance from a node to the nearest infective increases. The rewiring leads to regions of bistability where either an endemic or a disease-free steady state can exist. Fluctuations around the endemic state and the lifetime of the endemic state are considered. The fluctuations are found to exhibit power law behavior.

  8. 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. PMID:26372353

  9. The Zika epidemics and transplantation.

    Science.gov (United States)

    Silveira, Fernanda P; Campos, Silvia V

    2016-05-01

    In the last few months an epidemic of Zika virus (ZIKV) has affected several countries, and it continues to spread rapidly. This virus was initially thought to cause only a mild febrile illness; however, the current epidemic has shown that it is associated with serious complications. Increasing reports are linking ZIKV to devastating conditions such as microcephaly in newborns and important neurologic syndromes. Although ZIKV infection has not yet been reported in transplant recipients, it is likely that it will be reported soon because of the number of transplants performed in affected areas and global travel. We discuss the effect of ZIKV in transplantation and propose recommendations to prevent donor-derived infections. PMID:27197772

  10. 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.

  11. 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...... with a Markovian mobility model the synchronization process yields overall evolutionary dynamics for first and second conditional moments of synchronization error given geographical position. The established dynamics assume the shape of partial integro-differential equations and the swarm is subsequently studied...

  12. Epidemic Spreading with External Agents

    OpenAIRE

    Banerjee, Siddhartha; Gopalan, Aditya; Das, Abhik Kumar; Shakkottai, Sanjay

    2012-01-01

    We study epidemic spreading processes in large networks, when the spread is assisted by a small number of external agents: infection sources with bounded spreading power, but whose movement is unrestricted vis-\\`a-vis the underlying network topology. For networks which are `spatially constrained', we show that the spread of infection can be significantly speeded up even by a few such external agents infecting randomly. Moreover, for general networks, we derive upper-bounds on the order of the...

  13. Leptospirosis: A Silent Epidemic Disease

    OpenAIRE

    Maria Cristina Schneider; Michel Jancloes; Daniel F. Buss; Sylvain Aldighieri; Eric Bertherat; Patricia Najera; Galan, Deise I.; Kara Durski; Marcos A. Espinal

    2013-01-01

    This special issue of International Journal of Environmental Research and Public Health is dedicated to leptospirosis, an endemic zoonotic disease that is a cause of many acute undifferentiated fevers, especially in tropical countries [1,2]. While it can be debated whether leptospirosis is an emerging disease, it is evident that it is becoming an emerging public health problem. It is recognized as a disease of epidemic potential that has a significant health impact in many parts of the world.

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

    Science.gov (United States)

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

    2016-01-01

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

  15. 4Flu - an individual based simulation tool to study the effects of quadrivalent vaccination on seasonal influenza in Germany

    OpenAIRE

    Eichner, Martin; Schwehm, Markus; Hain, Johannes; Uphoff, Helmut; Salzberger, Bernd; Knuf, Markus; Schmidt-Ott, Ruprecht

    2014-01-01

    Background Influenza vaccines contain Influenza A and B antigens and are adjusted annually to match the characteristics of circulating viruses. In Germany, Influenza B viruses belonged to the B/Yamagata lineage, but since 2001, the antigenically distinct B/Victoria lineage has been co-circulating. Trivalent influenza vaccines (TIV) contain antigens of the two A subtypes A(H3N2) and A(H1N1), yet of only one B lineage, resulting in frequent vaccine mismatches. Since 2012, the WHO has been recom...

  16. Spectral clustering with epidemic diffusion

    Science.gov (United States)

    Smith, Laura M.; Lerman, Kristina; Garcia-Cardona, Cristina; Percus, Allon G.; Ghosh, Rumi

    2013-10-01

    Spectral clustering is widely used to partition graphs into distinct modules or communities. Existing methods for spectral clustering use the eigenvalues and eigenvectors of the graph Laplacian, an operator that is closely associated with random walks on graphs. We propose a spectral partitioning method that exploits the properties of epidemic diffusion. An epidemic is a dynamic process that, unlike the random walk, simultaneously transitions to all the neighbors of a given node. We show that the replicator, an operator describing epidemic diffusion, is equivalent to the symmetric normalized Laplacian of a reweighted graph with edges reweighted by the eigenvector centralities of their incident nodes. Thus, more weight is given to edges connecting more central nodes. We describe a method that partitions the nodes based on the componentwise ratio of the replicator's second eigenvector to the first and compare its performance to traditional spectral clustering techniques on synthetic graphs with known community structure. We demonstrate that the replicator gives preference to dense, clique-like structures, enabling it to more effectively discover communities that may be obscured by dense intercommunity linking.

  17. 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...

  18. Synthesis and Anti-Influenza Activity of Pyridine, Pyridazine, and Pyrimidine C-Nucleosides as Favipiravir (T-705) Analogues.

    Science.gov (United States)

    Wang, Guangyi; Wan, Jinqiao; Hu, Yujian; Wu, Xiangyang; Prhavc, Marija; Dyatkina, Natalia; Rajwanshi, Vivek K; Smith, David B; Jekle, Andreas; Kinkade, April; Symons, Julian A; Jin, Zhinan; Deval, Jerome; Zhang, Qingling; Tam, Yuen; Chanda, Sushmita; Blatt, Lawrence; Beigelman, Leonid

    2016-05-26

    Influenza viruses are responsible for seasonal epidemics and occasional pandemics which cause significant morbidity and mortality. Despite available vaccines, only partial protection is achieved. Currently, there are two classes of widely approved anti-influenza drugs: M2 ion channel blockers and neuraminidase inhibitors. However, the worldwide spread of drug-resistant influenza strains poses an urgent need for novel antiviral drugs, particularly with a different mechanism of action. Favipiravir (T-705), a broad-spectrum antiviral agent, has shown potent anti-influenza activity in cell-based assays, and its riboside (2) triphosphate inhibited influenza polymerase. In one of our approaches to treat influenza infection, we designed, prepared, and tested a series of C-nucleoside analogues, which have an analogy to 2 and were expected to act by a similar antiviral mechanism as favipiravir. Compound 3c of this report exhibited potent inhibition of influenza virus replication in MDCK cells, and its triphosphate was a substrate of and demonstrated inhibitory activity against influenza A polymerase. Metabolites of 3c are also presented. PMID:27120583

  19. Tackling influenza in Ghana

    OpenAIRE

    2012-01-01

    Knowing the burden of disease is just one of a number of influenza-related issues countries such as Ghana have to face. William Ampofo spoke with Ben Jones about projects aimed at combating the virus in the African region.

  20. The influenza enigma

    OpenAIRE

    2012-01-01

    Recent advances in microbiology and molecular sequencing have vastly improved our understanding of how human influenza viruses evolve and spread. But several unanswered questions continue to vex researchers. Patrick Adams reports.

  1. Recombinant influenza vaccines.

    Science.gov (United States)

    Sedova, E S; Shcherbinin, D N; Migunov, A I; Smirnov, Iu A; Logunov, D Iu; Shmarov, M M; Tsybalova, L M; Naroditskiĭ, B S; Kiselev, O I; Gintsburg, A L

    2012-10-01

    This review covers the problems encountered in the construction and production of new recombinant influenza vaccines. New approaches to the development of influenza vaccines are investigated; they include reverse genetics methods, production of virus-like particles, and DNA- and viral vector-based vaccines. Such approaches as the delivery of foreign genes by DNA- and viral vector-based vaccines can preserve the native structure of antigens. Adenoviral vectors are a promising gene-delivery platform for a variety of genetic vaccines. Adenoviruses can efficiently penetrate the human organism through mucosal epithelium, thus providing long-term antigen persistence and induction of the innate immune response. This review provides an overview of the practicability of the production of new recombinant influenza cross-protective vaccines on the basis of adenoviral vectors expressing hemagglutinin genes of different influenza strains. PMID:23346377

  2. Transmission of Flu (Influenza)

    Science.gov (United States)

    ... Skip Content Marketing Share this: Main Content Area Flu (Influenza) Transmission How Flu Spreads Coughing and Sneezing People with flu can ... not be shared without washing thoroughly first. The Flu Is Contagious You may be able to pass ...

  3. 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...

  4. Meningitis - H. influenzae

    Science.gov (United States)

    ... antibiotics may be considered. Always use good hygiene habits, such as washing hands before and after changing a diaper, and after using the bathroom. Alternative Names H. influenzae meningitis; H. flu meningitis ...

  5. 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 ...

  6. 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.

  7. RECOMBINANT INFLUENZA VACCINES

    OpenAIRE

    Sedova, E.; Shcherbinin, D.; Migunov, A.; Smirnov, Iu; Logunov, D.; Shmarov, M.; Tsybalova, L.; Naroditskiĭ, B.; O. Kiselev; Gintsburg, A.

    2012-01-01

    This review covers the problems encountered in the construction and production of new recombinant influenza vaccines. New approaches to the development of influenza vaccines are investigated; they include reverse genetics methods, production of virus-like particles, and DNA- and viral vector-based vaccines. Such approaches as the delivery of foreign genes by DNA- and viral vector-based vaccines can preserve the native structure of antigens. Adenoviral vectors are a promising gene-delivery pla...

  8. Oscillococcinum for influenza treatment

    OpenAIRE

    Luigi Alberto Marrari; Laurence Terzan; Gilles Chaufferin

    2012-01-01

    The use of a complementary medicine approach, and specifically of the popular medicine Oscillococcinum, for the treatment of influenza-like syndromes remains controversial. This brief paper analyses the currently available literature on this homeopathic preparation and the Cochrane Collaboration’s 2006 systematic review, along with other recent studies, in order to clarify certain fundamental aspects of its use in the treatment of influenza. In the light of the reported findings, and applying...

  9. Endocytosis of influenza viruses

    OpenAIRE

    Lakadamyali, Melike; Rust, Michael J.; Zhuang, Xiaowei

    2004-01-01

    Receptor-mediated endocytosis is known to play an important role in the entry of many viruses into host cells. However, the exact internalization mechanism has, until recently, remained poorly understood for many medically important viruses, including influenza. Developments in real-time imaging of single viruses as well as the use of dominant negative mutants to selectively block specific endocytic pathways, have improved our understanding of the influenza infection process.

  10. Influenza vaccination during pregnancy.

    OpenAIRE

    Goldman, Ran D.; Koren, Gideon

    2002-01-01

    QUESTION: A 27-year-old patient of mine recently learned she is pregnant. She took the influenza vaccine offered at work when she was 7 weeks pregnant. Is her fetus at risk of malformations? ANSWER: No evidence indicates that killed influenza vaccine is teratogenic, even if given during the first trimester. Since 1996, Health Canada's Centre for Disease Control and Prevention has recommended that pregnant women in their second and third trimesters be vaccinated. This should not be interpreted...

  11. BIRD FLU (AVIAN INFLUENZA)

    OpenAIRE

    Acar, Ali; 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, ...

  12. Equine influenza: An overview

    OpenAIRE

    S. P. Waghmare; S.G. Mode; A.Y. Kolte; Namrata Babhulkar; S. H. Vyavahare; Ajit Patel

    2010-01-01

    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 ...

  13. Avian influenza – Review

    OpenAIRE

    Öner, Ahmet Faik

    2007-01-01

    Recent spread of avian influenza A H5N1 virus to poultry and wild birds has increased the threat of human infections with H5N1 virus worldwide In this review the epidemiology virolgy clinical and laboratory characteristics and management of avian influenza is described The virus has demonsrated considerable pandemic potential and is the most likely candidate of next pandemic threat For pandemic preparedness stockpiling antiviral agents and vaccination are the most important intervention measu...

  14. Dengue and dengue hemorrhagic fever epidemics in Brazil: what research is needed based on trends, surveillance, and control experiences?

    OpenAIRE

    Maria da Glória Teixeira; Maria da Conceição Nascimento Costa; Maurício Lima Barreto; Eduardo Mota

    2005-01-01

    Dengue epidemics account annually for several million cases and deaths worldwide. The high endemic level of dengue fever and its hemorrhagic form correlates to extensive domiciliary infestation by Aedes aegypti and multiple viral serotype human infection. This study analyzed serial case reports registered in Brazil since 1981, describing incidence evolutionary patterns and spatial distribution. Epidemic waves followed the introduction of every serotype (DEN 1 to 3), and reduction in susceptib...

  15. 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.

  16. The Severity of Pandemic H1N1 Influenza in the United States, from April to July 2009: A Bayesian Analysis

    OpenAIRE

    Presanis, Anne M.; Daniela De Angelis; Angela Hagy; Carrie Reed; Steven Riley; Cooper, Ben S.; Lyn Finelli; Paul Biedrzycki; Marc Lipsitch

    2009-01-01

    Editors' Summary Background Every winter, millions of people catch influenza—a viral infection of the airways—and about half a million people die as a result. In the US alone, an average of 36,000 people are thought to die from influenza-related causes every year. These seasonal epidemics occur because small but frequent changes in the virus mean that an immune response produced one year provides only partial protection against influenza the next year. Occasionally, influenza viruses emerge t...

  17. Simultaneous detection of novel H7N9 and other influenza A viruses in poultry by multiplex real-time RT-PCR

    OpenAIRE

    Xu, Xiaolong; Bao, Hongmei; Ma, Yong; Sun, Jiashan; Zhao, Yuhui; Wang, Yunhe; Shi, Jianzhong; Zeng, Xianying; Li, Yanbing; Wang, Xiurong; Chen, Hualan

    2015-01-01

    Background A novel reassortant H7N9 influenza A virus has crossed the species barrier from poultry to cause human infections in China in 2013 and 2014. Rapid detection of the novel H7N9 virus is important to detect this virus in poultry and reduce the risk of an epidemic in birds or humans. Findings In this study, a multiplex real-time RT-PCR (rRT-PCR) assay for rapid detection of H7N9 and other influenza A viruses was developed. To evaluate the assay, various influenza A viruses, other avian...

  18. Influenza pandemics and avian flu

    OpenAIRE

    2005-01-01

    Douglas Fleming is general practitioner in a large suburban practice in Birmingham. In this article he seeks to clarify clinical issues relating to potential pandemics of influenza, including avian influenza

  19. Influenza Prevention: Information for Travelers

    Science.gov (United States)

    ... Medscape Podcasts Public Service Announcements (PSAs) Virus Images Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... this? Submit What's this? Submit Button Past Newsletters Influenza Prevention: Information for Travelers Language: English Español ...

  20. 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.

  1. A cross-immunization model for the extinction of old influenza strains.

    Science.gov (United States)

    Uekermann, Florian; Sneppen, Kim

    2016-01-01

    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. PMID:27174658

  2. [Influenza-related respiratory illnesses and associated causes among the elderly in a city in Northeast Brazil].

    Science.gov (United States)

    Gomes, Aline de Andrade; Nunes, Marco Antônio Prado; Oliveira, Cristiane Costa da Cunha; Lima, Sônia Oliveira

    2013-01-01

    Nationwide influenza vaccination campaigns are held annually in Brazil during the same time of the year. This study aimed to analyze deaths from respiratory illnesses and influenza-related causes among the elderly in the city of Aracaju, capital of Sergipe State, Brazil. Data were analyzed from the following databases: Information System on Influenza Epidemiological Surveillance (SIVEP_GRIPE), Hospital Information System (SIH), Mortality Information System (SIM), and Health Informatics Department (DATASUS), from 1998 to 2007, Sergipe State Central Laboratory (LACEN-SE), and rainfall data from the National Meteorology Institute (INMET). The year 2007 showed the highest mortality rate from influenza and related causes in elderly individuals. From 1998 to 2007, mortality rates from influenza-related respiratory illnesses and associated causes in Aracaju city were higher than in the States of Brazil, indicating the need to reformulate the influenza vaccination schedule in elderly residents of this city. PMID:23370031

  3. 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...

  4. The ESPID/ESWI Joint Symposium - A strong vote for universal influenza vaccination in children in Europe.

    Science.gov (United States)

    Kobbe, Robin

    2015-12-01

    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. PMID:26386163

  5. 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.

  6. Epidemic Model of Leptospirosis Containing Fractional Order

    OpenAIRE

    Muhammad Altaf Khan; Saddiq, S. F.; Saeed Islam; Ilyas Khan; Dennis Ling Chuan Ching

    2014-01-01

    We study an epidemic model of leptospirosis in fractional order numerically. The multistep generalized differential transform method is applied to find the accurate approximate solution of the epidemic model of leptospirosis disease in fractional order. A unique positive solution for the epidemic model in fractional order is presented. For the integer case derivative, the approximate solution of MGDTM is compared with the Runge-Kutta order four scheme. The numerical results are presented for ...

  7. Optimal control of epidemics in metapopulations

    OpenAIRE

    Rowthorn, Robert E.; Laxminarayan, Ramanan; Gilligan, Christopher A.

    2009-01-01

    Little is known about how best to deploy scarce resources for disease control when epidemics occur in different but interconnected regions. We use a combination of optimal control methods and epidemiological theory for metapopulations to address this problem. We consider what strategy should be used if the objective is to minimize the discounted number of infected individuals during the course of an epidemic. We show, for a system with two interconnected regions and an epidemic in which infec...

  8. Influenza: exposing the true killer

    OpenAIRE

    Van Epps, Heather L.

    2006-01-01

    In the early 1930s, Richard Shope isolated influenza virus from infected pigs. Shope's finding was quickly followed by the isolation of the influenza virus from humans, proving that a virus—not a bacterium, as was widely believed—caused influenza.

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

    OpenAIRE

    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. Settings General populations in Germany, the Netherlands, and the United Kingdom. Data sources Country specific patterns of social contact and demographic data. Model An age structured susceptibl...

  10. The Impact of the Unstructured Contacts Component in Influenza Pandemic Modeling

    OpenAIRE

    Marco Ajelli; Stefano Merler

    2008-01-01

    BACKGROUND: Individual based models have become a valuable tool for modeling the spatiotemporal dynamics of epidemics, e.g. influenza pandemic, and for evaluating the effectiveness of intervention strategies. While specific contacts among individuals into diverse environments (family, school/workplace) can be modeled in a standard way by employing available socio-demographic data, all the other (unstructured) contacts can be dealt with by adopting very different approaches. This can be achiev...

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

    OpenAIRE

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

    2016-01-01

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

  12. Distinct Host Tropism Protein Signatures to Identify Possible Zoonotic Influenza A Viruses

    OpenAIRE

    Christine L P Eng; Tong, Joo Chuan; Tan, Tin Wee

    2016-01-01

    Zoonotic influenza A viruses constantly pose a health threat to humans as novel strains occasionally emerge from the avian population to cause human infections. Many past epidemic as well as pandemic strains have originated from avian species. While most viruses are restricted to their primary hosts, zoonotic strains can sometimes arise from mutations or reassortment, leading them to acquire the capability to escape host species barrier and successfully infect a new host. Phylogenetic analyse...

  13. Spatiotemporal Analysis of the Genetic Diversity of Seal Influenza A(H10N7) Virus, Northwestern Europe

    DEFF Research Database (Denmark)

    Bodewes, Rogier; Zohari, Siamak; Krog, Jesper Schak;

    2016-01-01

    birds to seals, amino acid changes in HA may occur rapidly and are important for virus adaptation to its new mammalian host. Influenza A viruses are major pathogens for humans, domestic animals, and wildlife. In addition to the continuous circulation of influenza A viruses among various host species...... to various avian influenza A(H10N7) viruses. The collection of samples from infected seals during the course of the outbreak provided a unique opportunity to follow the adaptation of the avian virus to its new seal host. Sequence data for samples collected from 41 different seals from four different...... found in H10 viruses isolated from Eurasian birds. Also, sequence variation in the HA gene was greater at the beginning than at the end of the epidemic, when a number of the mutations observed earlier had been fixed. These results imply that when an avian influenza virus jumps the species barrier from...

  14. Avian influenza risk perception, Hong Kong

    OpenAIRE

    Fielding, Richard; Lam, Wendy W.T.; Ho, Ella Y.Y.; Lam, Tai Hing; Hedley, Anthony J.; Leung, Gabriel M

    2005-01-01

    A telephone survey of 986 Hong Kong households determined exposure and risk perception of avian influenza from live chicken sales. Householders bought 38,370,000 live chickens; 11% touched them when buying, generating 4,220,000 exposures annually; 36% (95% confidence interval [CI] 33%–39%) perceived this as risky, 9% (7%–11%) estimated >50% likelihood of resultant sickness, whereas 46% (43%–49%) said friends worried about such sickness. Recent China travel (adjusted odds ratio 0.35; CI 0.13–0...

  15. Opioids: The Prescription Drug & Heroin Overdose Epidemic

    Science.gov (United States)

    ... Pain Medication Facts Prevention Treatment & Recovery Overdose Response Health Professionals Resources Law Enforcement Resources Opioids: The Prescription Drug & Heroin Overdose Epidemic Opioids are natural or synthetic chemicals ...

  16. Vaccine Effectiveness Against Laboratory-Confirmed Influenza Hospitalizations Among Elderly Adults During the 2010–2011 Season

    Science.gov (United States)

    Kwong, Jeffrey C.; Campitelli, Michael A.; Gubbay, Jonathan B.; Peci, Adriana; Winter, Anne-Luise; Olsha, Romy; Turner, Robert; Rosella, Laura C.; Crowcroft, Natasha S.

    2013-01-01

    Background. Although annual influenza immunization is recommended for adults aged ≥65 years due to the substantial burden of illness, the evidence base for this recommendation is weak. Prior observational studies that examined influenza vaccine effectiveness against nonspecific serious outcomes suffered from selection bias and the lack of laboratory confirmation for influenza infection. The objective of this study was to determine the effectiveness of the 2010–2011 seasonal influenza vaccine against laboratory-confirmed influenza hospitalizations among community-dwelling elderly adults, a serious and highly specific outcome. Methods. We conducted a test-negative study of community-dwelling adults aged >65 years in Ontario, Canada. Respiratory specimens collected between 1 December 2010 and 30 April 2011 from patients admitted to acute care hospitals were tested for influenza using nucleic acid amplification techniques. Influenza vaccination was ascertained from physician billing claims through linkage to health administrative datasets. Results. Receipt of the 2010–2011 seasonal influenza vaccine was associated with a 42% (95% confidence interval, 29%–53%) reduction in laboratory-confirmed influenza hospitalizations. Vaccine effectiveness estimates were consistent across age groups, by sex, and regardless of outcome severity, timing of testing, and when considering individuals vaccinated <7 or <14 days prior to admission as unvaccinated. Conclusions. Results of this study will better inform decision making regarding influenza vaccination of elderly adults. Similar analyses are needed annually due to antigenic drift and frequent changes in influenza vaccine composition. The linkage of routinely collected laboratory testing and health administrative data represents an efficient method for estimating influenza vaccine effectiveness that complements prospective studies. PMID:23788243

  17. SNPer: An R Library for Quantitative Variant Analysis on Single Nucleotide Polymorphisms among Influenza Virus Populations

    Science.gov (United States)

    Sangket, Unitsa; Vijasika, Sukanya; Noh, Hasnee; Chantratita, Wasun; Klungthong, Chonticha; Yoon, In Kyu; Fernandez, Stefan; Rutvisuttinunt, Wiriya

    2015-01-01

    Influenza virus (IFV) can evolve rapidly leading to genetic drifts and shifts resulting in human and animal influenza epidemics and pandemics. The genetic shift that gave rise to the 2009 influenza A/H1N1 pandemic originated from a triple gene reassortment of avian, swine and human IFVs. More minor genetic alterations in genetic drift can lead to influenza drug resistance such as the H274Y mutation associated with oseltamivir resistance. Hence, a rapid tool to detect IFV mutations and the potential emergence of new virulent strains can better prepare us for seasonal influenza outbreaks as well as potential pandemics. Furthermore, identification of specific mutations by closely examining single nucleotide polymorphisms (SNPs) in IFV sequences is essential to classify potential genetic markers associated with potentially dangerous IFV phenotypes. In this study, we developed a novel R library called “SNPer” to analyze quantitative variants in SNPs among IFV subpopulations. The computational SNPer program was applied to three different subpopulations of published IFV genomic information. SNPer queried SNPs data and grouped the SNPs into (1) universal SNPs, (2) likely common SNPs, and (3) unique SNPs. SNPer outperformed manual visualization in terms of time and labor. SNPer took only three seconds with no errors in SNP comparison events compared with 40 hours with errors using manual visualization. The SNPer tool can accelerate the capacity to capture new and potentially dangerous IFV strains to mitigate future influenza outbreaks. PMID:25876137

  18. Sialylated immunoglobulin G can neutralize influenza virus infection through receptor mimicry

    Science.gov (United States)

    Zhao, Conghui; Liu, Xingmu; Zhang, Zaiping; Li, Tongfei; Sun, Ruiman; Gu, Huan; Gu, Jiang

    2016-01-01

    Influenza viruses possess a great threat to human health, but there is still no effective drug to deal with the outbreak of possible new influenza subtypes. In this study, we first fractionated sialylated immunoglobulin G (IgG), mainly Fab sialylated fraction, with sambucus nigra agglutinin affinity chromatography. We then demonstrated that sialylated IgG possessed more effective neutralizing activity against 2009 A (H1N1) subtype than that of IgG mixture, and sialosides on the Fab is crucial in this neutralization reaction as when such residues were removed with neuraminidase A digestion the blocking effect was significantly reduced. It appears that sialic acid residues attached to Fab could serve as binding moieties to receptor binding site of influenza virus. These findings indicate that sialylated IgG probably is an effective anti-influenza broad-spectrum drug utilizing its receptor mimicry to competitively inhibit the attachment of influenza viruses with sialic acid receptors on target cells. This property would be particularly useful if it can be applied to prevent newly emerged influenza virus strain infections in future epidemics. PMID:26870994

  19. [Thalidomide epidemics: 50 years after].

    Science.gov (United States)

    Sípek, Antonín; Sípek, Antonín; Maňáková, Eva

    2012-01-01

    Thalidomide tragedy and the subsequent epidemics of congenital anomalies is one of the most tragic but also enlightening chapters in the history of modern medicine. Many thousands of children were born with various anomalies - especially with limb deformities - because of the mass usage of thalidomide by pregnant women. The numbers of the spontaneous abortions and fetal deaths will remain unknown forever. In year 2012 we have a sad 50th anniversary of final recognition of thalidomide teratogenous potential. The causes of this tragedy and subsequent actions are summarized in our text.Key words: thalidomide, teratogenesis, congenital anomalies. PMID:23387816

  20. Risk perception in epidemic modeling

    OpenAIRE

    Bagnoli, Franco; Lio, Pietro; Sguanci, Luca

    2007-01-01

    We investigate the effects of risk perception in a simple model of epidemic spreading. We assume that the perception of the risk of being infected depends on the fraction of neighbors that are ill. The effect of this factor is to decrease the infectivity, that therefore becomes a dynamical component of the model. We study the problem in the mean-field approximation and by numerical simulations for regular, random and scale-free networks. We show that for homogeneous and random networks, there...

  1. 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.

  2. 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.

  3. 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.

  4. Improving Influenza Vaccination Rates— A Straightforward Task or a Multifaceted Challenge?

    OpenAIRE

    Ljiljana Trtica-Majnaric

    2013-01-01

    Annual vaccination with trivalent inactivated vaccines has been proven as safe and efficacious in preventing influenza and its complications. It is recommended especially to the elderly (>65) and other people at high risk for influenza complications and death such as patients with chronic medical conditions. Healthcare workers, who are considered to transmit infection to patients, or reciprocally, can be infected during encounters with patients, are also strongly advised to regularly receive...

  5. Melaleuca alternifolia Concentrate Inhibits in Vitro Entry of Influenza Virus into Host Cells

    OpenAIRE

    Lifang Jiang; Huaiyu Gu; Danyun Fang; Maxwell John Reynolds; Yue Yin; Junmei Zhou; Gucheng Zeng; Alfred King-Yin Lam; Jun Xu; Songwei Duan; Cordia Chu; Xinghua Li

    2013-01-01

    Influenza virus causes high morbidity among the infected population annually and occasionally the spread of pandemics. Melaleuca alternifolia Concentrate (MAC) is an essential oil derived from a native Australian tea tree. Our aim was to investigate whether MAC has any in vitro inhibitory effect on influenza virus infection and what mechanism does the MAC use to fight the virus infection. In this study, the antiviral activity of MAC was examined by its inhibition of cytopathic effects. In sil...

  6. A Randomized Trial of One vs. Two Doses of Influenza Vaccine Following Allogeneic Transplantation

    OpenAIRE

    Karras, Nicole A.; Weeres, Matthew; Sessions, Wendy; Xu, Xiyan; DeFor, Todd; Young, Jo-Anne H.; Stefanski, Heather; Brunstein, Claudio; Cooley, Sarah; Miller, Jeffrey S.; Blazar, Bruce R.; Wagner, John E.; Verneris, Michael R.

    2012-01-01

    Influenza infection following allogeneic hematopoietic cell transplantation (allo-HCT) can result in severe complications. The effectiveness of the annual vaccine depends on age, immune competence and the antigenic potential of the 3 strains included (1). . We hypothesized that a second vaccine dose, the standard of care for vaccine-naïve children, might improve post-HCT immune responses. Patients >60 days post-HCT were randomized to receive either 1 (n=33) or 2 (n=32) influenza vaccine doses...

  7. Examining Perceptions about Mandatory Influenza Vaccination of Healthcare Workers through Online Comments on News Stories

    OpenAIRE

    Lei, Yang; Pereira, Jennifer A.; Quach, Susan; Bettinger, Julie A; Kwong, Jeffrey C.; Corace, Kimberly; Garber, Gary; Feinberg, Yael; Guay, Maryse; . .

    2015-01-01

    Background The aim of this study was to understand online public perceptions of the debate surrounding the choice of annual influenza vaccinations or wearing masks as a condition of employment for healthcare workers, such as the one enacted in British Columbia in August 2012. Methods Four national and 82 local (British Columbia) Canadian online news sites were searched for articles posted between August 2012 and May 2013 containing the words “healthcare workers” and “mandatory influenza vacci...

  8. 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. PMID:22737835

  9. 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.

  10. AIDS epidemic runs riot in South Africa.

    Science.gov (United States)

    1997-05-27

    Based on current health surveys in South Africa, the HIV and AIDS epidemic there is spreading faster than health workers can develop a policy to combat it. 120 million male and 90,000 female condoms have been distributed to the areas that are most affected. According to Health Minister Nkosazana Zuma, the percentage of HIV-positive pregnant women in the North-West Province rose from 8.3% in 1995 to 25% in 1997. In June 1996, 1.7 million people were at risk; this number rose to 2.5 million in 1997, 90,000 of whom will develop advanced AIDS by the end of the year. According to independent researchers, 800 people are infected daily, which means that 16% of South Africa's workers are already infected. This figure could rise to 20% by the year 2000 according to Professor Ronald Green-Thompson. At that time, the cost to the South African economy would be between US$25 million and US$2.3 billion. The World Health Organization (WHO) is touring provinces for the first time to select sites for use by assessment teams in July. Dr. Liz Floyd, head of the HIV/AIDS and communicable diseases unit, states that, although US$6.1 million (US$2.3 million more than in 1996) have been designated to fight the epidemic, new measures have to be found to avoid an infection rate of 1 in 5 young women by the end of the year. The unit conducts annual surveys among women attending public prenatal clinics. Infection appears to be linked to poverty, migration, family breakdowns, and prostitution. The greatest increase has been among women aged 20-24 years. According to Floyd, "the supply of condoms is still uneven and unreliable, especially in high density peri-urban settlements and shanty towns. Primary care for the youth and home-based schemes are poorly coordinated and erratic." Zuma believes that schools should be targeted; she hopes to educate children in 7400 secondary and 13,500 primary schools. Donor agencies, churches, workers, and business people have become involved, including

  11. L-carnosine modulates respiratory burst and reactive oxygen species production in neutrophil biochemistry and function: may oral dosage form of non-hydrolized dipeptide L-carnosine complement anti-infective anti-influenza flu treatment, prevention and self-care as an alternative to the conventional vaccination?

    Science.gov (United States)

    Babizhayev, Mark A; Deyev, Anatoliy I; Yegorov, Yegor E

    2014-05-01

    Influenza A is a viral disease of global dimension, presenting with high morbidity and mortality in annual epidemics, and in pandemics which are of infrequent occurrence but which have very high attack rates. Influenza vaccines of the future must be directed toward use of conserved group-specific viral antigens, such as are present in transitional proteins which are exposed during the fusion of virus to the host cell. Influenza probes revealed a continuing battle for survival between host and parasite in which the host population updates the specificity of its pool of humoral immunity by contact with and response to infection with the most recent viruses which possess altered antigenic specificity in their hemagglutinin (HA) ligand. It is well known that the HA protein is found on the surface of the influenza virus particle and is responsible for binding to receptors on host cells and initiating infection. Polymorphonuclear neutrophils (PMN) have been reported to be involved in the initial host response to influenza A virus (IAV). Early after IAV infection, neutrophils infiltrate the airway probably due to release of chemokines that attract PMN. Clearly, severe IAV infection is characterized by increased neutrophil influx into the lung or upper respiratory tract. Carnosine (β-alanyl-L-histidine) and anserine (N-β-alanyl-1-methyl-L-histidine) are found in skeletal muscle of most vertebrates, including those used for food; for example, 100 g of chicken breast contains 400 mg (17.6 mmol/L) of carnosine and 1020 mg (33.6 mmol/l) of anserine. Carnosine-stimulated respiratory burst in neutrophils is a universal biological mechanism of influenza virus destruction. Our own studies revealed previously unappreciated functional effects of carnosine and related histidine containing compounds as a natural biological prevention and barrier against Influenza virus infection, expand public understanding of the antiviral properties of imidazole-containing dipeptide based

  12. 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.

  13. Spanish flu, Asian flu, Hong Kong flu, and seasonal influenza in Japan under social and demographic influence: review and analysis using the two-population model.

    Science.gov (United States)

    Yoshikura, Hiroshi

    2014-01-01

    When cumulative numbers of patients (X) and deaths (Y) associated with an influenza epidemic are plotted using the log-log scale, the plots fall on an ascending straight line generally expressed as logY = k(logX - logN0). For the 2009 H1N1 influenza pandemic, the slope k was ~0.6 for Mexico and ~2 for other countries. The two-population model was proposed to explain this phenomenon (Yoshikura H. Jpn J Infect Dis. 2012;65:279-88; Yoshikura H. Jpn J Infect Dis. 2009;62:411-2; and Yoshikura H. Jpn J Infect Dis. 2009;62:482-4). The current article reviews and analyzes previous influenza epidemics in Japan to examine whether the two-population model is applicable to them. The slope k was found to be ~2 for the Spanish flu during 1918-1920 and the Asian flu during 1957-1958, and ~1 for the Hong Kong flu and seasonal influenza prior to 1960-1961; however, k was ~0.6 for seasonal influenza after 1960-1961. This transition of the slope k of seasonal influenza plots from ~1 to ~0.6 corresponded to the shift in influenza mortality toward the older age groups and a drastic reduction in infant mortality rates due to improvements in the standard of living during the 1950s and 1960s. All the above observations could be well explained by reconstitution of the influenza epidemic based on the two-population model. PMID:25056069

  14. Antiviral resistance and the control of pandemic influenza.

    Directory of Open Access Journals (Sweden)

    Marc Lipsitch

    2007-01-01

    Full Text Available BACKGROUND: The response to the next influenza pandemic will likely include extensive use of antiviral drugs (mainly oseltamivir, combined with other transmission-reducing measures. Animal and in vitro studies suggest that some strains of influenza may become resistant to oseltamivir while maintaining infectiousness (fitness. Use of antiviral agents on the scale anticipated for the control of pandemic influenza will create an unprecedented selective pressure for the emergence and spread of these strains. Nonetheless, antiviral resistance has received little attention when evaluating these plans. METHODS AND FINDINGS: We designed and analyzed a deterministic compartmental model of the transmission of oseltamivir-sensitive and -resistant influenza infections during a pandemic. The model predicts that even if antiviral treatment or prophylaxis leads to the emergence of a transmissible resistant strain in as few as 1 in 50,000 treated persons and 1 in 500,000 prophylaxed persons, widespread use of antivirals may strongly promote the spread of resistant strains at the population level, leading to a prevalence of tens of percent by the end of a pandemic. On the other hand, even in circumstances in which a resistant strain spreads widely, the use of antivirals may significantly delay and/or reduce the total size of the pandemic. If resistant strains carry some fitness cost, then, despite widespread emergence of resistance, antivirals could slow pandemic spread by months or more, and buy time for vaccine development; this delay would be prolonged by nondrug control measures (e.g., social distancing that reduce transmission, or use of a stockpiled suboptimal vaccine. Surprisingly, the model suggests that such nondrug control measures would increase the proportion of the epidemic caused by resistant strains. CONCLUSIONS: The benefits of antiviral drug use to control an influenza pandemic may be reduced, although not completely offset, by drug resistance

  15. Evolutionary Dynamics of Local Pandemic H1N1/2009 Influenza Virus Lineages Revealed by Whole-Genome Analysis

    Science.gov (United States)

    Baillie, Gregory J.; Galiano, Monica; Agapow, Paul-Michael; Myers, Richard; Chiam, Rachael; Gall, Astrid; Palser, Anne L.; Watson, Simon J.; Hedge, Jessica; Underwood, Anthony; Platt, Steven; McLean, Estelle; Pebody, Richard G.; Rambaut, Andrew; Green, Jonathan; Daniels, Rod; Pybus, Oliver G.; Zambon, Maria

    2012-01-01

    Virus gene sequencing and phylogenetics can be used to study the epidemiological dynamics of rapidly evolving viruses. With complete genome data, it becomes possible to identify and trace individual transmission chains of viruses such as influenza virus during the course of an epidemic. Here we sequenced 153 pandemic influenza H1N1/09 virus genomes from United Kingdom isolates from the first (127 isolates) and second (26 isolates) waves of the 2009 pandemic and used their sequences, dates of isolation, and geographical locations to infer the genetic epidemiology of the epidemic in the United Kingdom. We demonstrate that the epidemic in the United Kingdom was composed of many cocirculating lineages, among which at least 13 were exclusively or predominantly United Kingdom clusters. The estimated divergence times of two of the clusters predate the detection of pandemic H1N1/09 virus in the United Kingdom, suggesting that the pandemic H1N1/09 virus was already circulating in the United Kingdom before the first clinical case. Crucially, three clusters contain isolates from the second wave of infections in the United Kingdom, two of which represent chains of transmission that appear to have persisted within the United Kingdom between the first and second waves. This demonstrates that whole-genome analysis can track in fine detail the behavior of individual influenza virus lineages during the course of a single epidemic or pandemic. PMID:22013031

  16. Evolutionary dynamics of local pandemic H1N1/2009 influenza virus lineages revealed by whole-genome analysis.

    Science.gov (United States)

    Baillie, Gregory J; Galiano, Monica; Agapow, Paul-Michael; Myers, Richard; Chiam, Rachael; Gall, Astrid; Palser, Anne L; Watson, Simon J; Hedge, Jessica; Underwood, Anthony; Platt, Steven; McLean, Estelle; Pebody, Richard G; Rambaut, Andrew; Green, Jonathan; Daniels, Rod; Pybus, Oliver G; Kellam, Paul; Zambon, Maria

    2012-01-01

    Virus gene sequencing and phylogenetics can be used to study the epidemiological dynamics of rapidly evolving viruses. With complete genome data, it becomes possible to identify and trace individual transmission chains of viruses such as influenza virus during the course of an epidemic. Here we sequenced 153 pandemic influenza H1N1/09 virus genomes from United Kingdom isolates from the first (127 isolates) and second (26 isolates) waves of the 2009 pandemic and used their sequences, dates of isolation, and geographical locations to infer the genetic epidemiology of the epidemic in the United Kingdom. We demonstrate that the epidemic in the United Kingdom was composed of many cocirculating lineages, among which at least 13 were exclusively or predominantly United Kingdom clusters. The estimated divergence times of two of the clusters predate the detection of pandemic H1N1/09 virus in the United Kingdom, suggesting that the pandemic H1N1/09 virus was already circulating in the United Kingdom before the first clinical case. Crucially, three clusters contain isolates from the second wave of infections in the United Kingdom, two of which represent chains of transmission that appear to have persisted within the United Kingdom between the first and second waves. This demonstrates that whole-genome analysis can track in fine detail the behavior of individual influenza virus lineages during the course of a single epidemic or pandemic. PMID:22013031

  17. 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

  18. Comparison of the Directigen Flu A+B Test, the QuickVue Influenza Test, and Clinical Case Definition to Viral Culture and Reverse Transcription-PCR for Rapid Diagnosis of Influenza Virus Infection

    Science.gov (United States)

    Ruest, Annie; Michaud, Sophie; Deslandes, Sylvie; Frost, Eric H.

    2003-01-01

    The diagnostic performances of the clinical case definition of influenza virus infection based on the combination of fever and cough and of two rapid influenza diagnostic tests, the Directigen Flu A+B test (Directigen; BD Diagnostic Systems, Sparks, Md.) and the QuickVue influenza test (QuickVue; Quidel, San Diego, Calif.), were compared to those of viral culture and an in-house reverse transcription (RT)-PCR during the 2000-2001 flu season. Two hundred consecutive nasopharyngeal aspirates were analyzed from 192 patients, including 122 adults and 70 children. Viral culture identified influenza virus A in 16 samples and influenza virus B in 55 samples, whereas RT-PCR identified influenza virus A in 21 samples and influenza virus B in 64 samples. When RT-PCR was used as the reference standard, the likelihood ratios for a positive test were 40.0 for Directigen, 8.6 for QuickVue, and 1.4 for the combination of fever and cough, whereas the likelihood ratios for a negative test were 0.22, 0.16, and 0.48, respectively. Our study suggests that (i) the poor specificity (35 to 58%) and the poor positive predictive value (41 to 60%) of the clinical case definition of influenza preclude its use for prediction of influenza virus infections during epidemics, especially when infection control decision making in the hospital setting is considered; (ii) Directigen has a higher diagnostic yield than QuickVue but is associated with a larger number of invalid results; (iii) the sensitivities of the rapid diagnostic tests are significantly lower with samples from adults than with samples from children, with the rates of false-negative results reaching up to 29%; and (iv) RT-PCR detects more cases of influenza than viral culture, and this greater accuracy makes it a more useful reference standard. PMID:12904343

  19. Nationwide surveillance of influenza during the pandemic (2009-10 and post-pandemic (2010-11 periods in Taiwan.

    Directory of Open Access Journals (Sweden)

    Jen-Hsiang Chuang

    Full Text Available INTRODUCTION: Although WHO declared the world moving into the post-pandemic period on August 10, 2010, influenza A(H1N1 2009 virus continued to circulate globally. Its impact was expected to continue during the 2010-11 influenza season. This study describes the nationwide surveillance findings of the pandemic and post-pandemic influenza periods in Taiwan and assesses the impact of influenza A(H1N1 2009 during the post-pandemic period. METHODS: The Influenza Laboratory Surveillance Network consisted of 12 contract laboratories for collecting and testing samples with acute respiratory tract infections. Surveillance of emergency room visits and outpatient department visits for influenza-like illness (ILI were conducted using the Real-Time Outbreak and Disease Surveillance system and the National Health Insurance program data, respectively. Hospitalized cases with severe complications and deaths were reported to the National Notifiable Disease Surveillance System. RESULTS: During the 2009-10 influenza season, pandemic A(H1N1 2009 was the predominant circulating strain and caused 44 deaths. However, the 2010-11 influenza season began with A(H3N2 being the predominant circulating strain, changing to A(H1N1 2009 in December 2010. Emergency room and outpatient department ILI surveillance displayed similar trends. By March 31, 2011, there were 1,751 cases of influenza with severe complications; 50.1% reported underlying diseases. Of the reported cases, 128 deaths were associated with influenza. Among these, 93 (72.6% were influenza A(H1N1 2009 and 30 (23.4% A(H3N2. Compared to the pandemic period, during the immediate post-pandemic period, increased number of hospitalizations and deaths were observed, and the patients were consistently older. CONCLUSIONS: Reemergence of influenza A(H1N1 2009 during the 2010-11 influenza season had an intense activity with age distribution shift. To further mitigate the impact of future influenza epidemics, Taiwan must

  20. Evaluation of two influenza surveillance systems in South Africa.

    Directory of Open Access Journals (Sweden)

    Eric Budgell

    Full Text Available The World Health Organisation recommends outpatient influenza-like illness (ILI and inpatient severe acute respiratory illness (SARI surveillance. We evaluated two influenza surveillance systems in South Africa: one for ILI and another for SARI.The Viral Watch (VW programme has collected virological influenza surveillance data voluntarily from patients with ILI since 1984 in private and public clinics in all 9 South African provinces. The SARI surveillance programme has collected epidemiological and virological influenza surveillance data since 2009 in public hospitals in 4 provinces by dedicated personnel. We compared nine surveillance system attributes from 2009-2012.We analysed data from 18,293 SARI patients and 9,104 ILI patients. The annual proportion of samples testing positive for influenza was higher for VW (mean 41% than SARI (mean 8% and generally exceeded the seasonal threshold from May to September (VW: weeks 21-40; SARI: weeks 23-39. Data quality was a major strength of SARI (most data completion measures >90%; adherence to definitions: 88-89% and a relative weakness of the VW programme (62% of forms complete, with limited epidemiologic data collected; adherence to definitions: 65-82%. Timeliness was a relative strength of both systems (e.g. both collected >93% of all respiratory specimens within 7 days of symptom onset. ILI surveillance was more nationally representative, financially sustainable and expandable than the SARI system. Though the SARI programme is not nationally representative, the high quality and detail of SARI data collection sheds light on the local burden and epidemiology of severe influenza-associated disease.To best monitor influenza in South Africa, we propose that both ILI and SARI should be under surveillance. Improving ILI surveillance will require better quality and more systematic data collection, and SARI surveillance should be expanded to be more nationally representative, even if this requires scaling

  1. Estimating the day of highly pathogenic avian influenza (H7N7) virus introduction into a poultry flock based on mortality data

    NARCIS (Netherlands)

    Bos, M.E.H.; Boven, van R.M.; Nielen, M.; Bouma, A.; Elbers, A.R.W.; Nodelijk, G.; Koch, G.; Stegeman, A.; Jong, de M.C.M.

    2007-01-01

    Despite continuing research efforts, knowledge of the transmission of the highly pathogenic avian influenza (HPAI) virus still has considerable gaps, which complicates epidemic control. The goal of this research was to develop a model to back-calculate the day HPAI virus is introduced into a flock,

  2. Epidemic Survivability: Characterizing Networks Under Epidemic-like Failure Propagation Scenarios

    DEFF Research Database (Denmark)

    Manzano, Marc; Calle, Eusebi; Ripoll, Jordi; Fagertun, Anna Manolova; Torres-Padrosa, Víctor

    Epidemics theory has been used in different contexts in order to describe the propagation of diseases, human interactions or natural phenomena. In computer science, virus spreading has been also characterized using epidemic models. Although in the past the use of epidemic models 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...

  3. 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。

  4. The Saudi Thoracic Society guidelines for influenza vaccinations

    Directory of Open Access Journals (Sweden)

    Mohammed O Zeitouni

    2015-01-01

    Full Text Available Influenza viruses are responsible for the influenza outbreaks that lead to significant burden and cause significant morbidity and mortality worldwide. Based on the core proteins, influenza viruses are classified into three types, A, B, and C, of which only A and B cause significant human disease and so the vaccine is directed against these two subtypes only. The effectiveness of the vaccine depends on boosting the immune system against the serotypes included within it. As influenza viruses undergo periodic changes in their antigen, the vaccine is modified annually to ensure susceptibility. In contrast to other countries, Saudi Arabia faces a unique and challenging situation due to Hajj and Umrah seasons, when millions of people gather at the holy places in Mecca and Madinah, during which influenza outbreaks are commonly found. Such challenges making the adoption of strict vaccination strategy in Saudi Arabia is of great importance. All efforts were made to develop this guideline in an easy-to-read form, making it very handy and easy to use by health care workers. The guideline was designed to provide recommendations for problems frequently encountered in real life, with special consideration for special situations such as Hajj and Umrah seasons and pregnancy.

  5. Epidemic corruption: a bio-economic homology

    OpenAIRE

    Hathroubi, Salem

    2013-01-01

    This paper aims to study corruption as an epidemic phenomenon using the epidemic diffusion model of Kermack and Mc-Kendrick (1927). We seek to determine the dynamics of corruption and its impact on the composition of the population at a given time. We determine a threshold epidemiological corruption based on the approximation of the honest population.

  6. Reemerging Threat of Epidemic Typhus in Algeria

    OpenAIRE

    Mokrani, K.; Fournier, P E; Dalichaouche, M.; Tebbal, S.; Aouati, A.; Raoult, D

    2004-01-01

    We report a case of epidemic typhus in a patient from the Batna region of Algeria, who presented with generalized febrile exanthema. The clinical diagnosis was confirmed by serological cross-adsorption followed by Western blotting. Our report emphasizes the threat of epidemic typhus in the highlands of Algeria.

  7. 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...

  8. Malaria Epidemic and Drug Resistance, Djibouti

    OpenAIRE

    Rogier, Christophe; Pradines, Bruno; H. Bogreau; 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.

  9. 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.

  10. Phylogenetic diversity and genotypical complexity of H9N2 influenza A viruses revealed by genomic sequence analysis.

    Directory of Open Access Journals (Sweden)

    Guoying Dong

    Full Text Available H9N2 influenza A viruses have become established worldwide in terrestrial poultry and wild birds, and are occasionally transmitted to mammals including humans and pigs. To comprehensively elucidate the genetic and evolutionary characteristics of H9N2 influenza viruses, we performed a large-scale sequence analysis of 571 viral genomes from the NCBI Influenza Virus Resource Database, representing the spectrum of H9N2 influenza viruses isolated from 1966 to 2009. Our study provides a panoramic framework for better understanding the genesis and evolution of H9N2 influenza viruses, and for describing the history of H9N2 viruses circulating in diverse hosts. Panorama phylogenetic analysis of the eight viral gene segments revealed the complexity and diversity of H9N2 influenza viruses. The 571 H9N2 viral genomes were classified into 74 separate lineages, which had marked host and geographical differences in phylogeny. Panorama genotypical analysis also revealed that H9N2 viruses include at least 98 genotypes, which were further divided according to their HA lineages into seven series (A-G. Phylogenetic analysis of the internal genes showed that H9N2 viruses are closely related to H3, H4, H5, H7, H10, and H14 subtype influenza viruses. Our results indicate that H9N2 viruses have undergone extensive reassortments to generate multiple reassortants and genotypes, suggesting that the continued circulation of multiple genotypical H9N2 viruses throughout the world in diverse hosts has the potential to cause future influenza outbreaks in poultry and epidemics in humans. We propose a nomenclature system for identifying and unifying all lineages and genotypes of H9N2 influenza viruses in order to facilitate international communication on the evolution, ecology and epidemiology of H9N2 influenza viruses.

  11. 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.

  12. 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.

  13. [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. PMID:19240010

  14. Phylodynamics of influenza A(H3N2) in South America, 1999-2012.

    Science.gov (United States)

    Born, Priscila Silva; Siqueira, Marilda Mendonça; Faria, Nuno Rodrigues; Resende, Paola Cristina; Motta, Fernando Couto; Bello, Gonzalo

    2016-09-01

    The limited influenza A(H3N2) genetic data available from the Southern Hemisphere (particularly from Africa and Latin America), constrains the accurate reconstruction of viral dissemination dynamics within those regions. Our objective was to describe the spatial dissemination dynamics of influenza A(H3N2) within South America. A total of 469 sequences of the HA1 portion of the hemagglutinin gene (HA) from influenza A(H3N2) viruses sampled in temperate and tropical South American countries between 1999 and 2012 were combined with available contemporary sequences from Australia, Hong Kong, United Kingdom and the United States. Phylogenetic analyses revealed that influenza A(H3N2) sequences from South America were highly intermixed with sequences from other geographical regions, although a clear geographic virus population structure was detected globally. We identified 14 clades mostly (≥80%) composed of influenza sequences from South American countries. Bayesian phylogeographic analyses of those clades support a significant role of both temperate and tropical regions in the introduction and dissemination of new influenza A(H3N2) strains within South America and identify an intensive bidirectional viral exchange between different geographical areas. These findings indicate that seasonal influenza A(H3N2) epidemics in South America are seeded by both the continuous importation of viral variants from other geographic regions and the short-term persistence of local lineages. This study also supports a complex metapopulation model of influenza A(H3N2) dissemination in South America, with no preferential direction in viral movement between temperate and tropical regions. PMID:27275847

  15. 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...

  16. A break in the obesity epidemic?

    DEFF Research Database (Denmark)

    Visscher, T L S; Heitmann, B L; Rissanen, A;

    2015-01-01

    epidemic. However, follow-ups of short duration may, in part, explain the apparent break or decrease in the obesity epidemic. On the other hand, a single focus on body mass index (BMI) ⩾25 or ⩾30 kg m(-)(2) is likely to mask a real increase in the obesity epidemic. And, in both children and adults, trends......Recent epidemiologic papers are presenting prevalence data suggesting breaks and decreases in obesity rates. However, before concluding that the obesity epidemic is not increasing anymore, the validity of the presented data should be discussed more thoroughly. We had a closer look...... into the literature presented in recent reviews to address the major potential biases and distortions, and to develop insights about how to interpret the presented suggestions for a potential break in the obesity epidemic. Decreasing participation rates, the use of reported rather than measured data and small sample...

  17. Influenza in pregnancy

    OpenAIRE

    Memoli, Matthew J.; Harvey, Hillery; Morens, David M.; Taubenberger, Jeffery K.

    2012-01-01

    Please cite this paper as: Memoli et al. (2012) Influenza in pregnancy. Influenza and Other Respiratory Viruses 00(00), 000–000. The 2009 pandemic served as a strong reminder that influenza‐induced disease can have a great impact on certain at‐risk populations and that pregnant women are one such important population. The increased risk of fatal and severe disease in these women was appreciated more than 500 years ago, and during the last century, pregnant women and their newborns have contin...

  18. Evidence compendium and advice on social distancing and other related measures for response to an influenza pandemic.

    Science.gov (United States)

    Rashid, Harunor; Ridda, Iman; King, Catherine; Begun, Matthew; Tekin, Hatice; Wood, James G; Booy, Robert

    2015-03-01

    The role of social distancing measures in mitigating pandemic influenza is not precisely understood. To this end, we have conducted a systematised review, particularly in light of the 2009 pandemic influenza, to better inform the role of social distancing measures against pandemic influenza. Articles were identified from relevant databases and the data were synthesised to provide evidence on the role of school or work place-based interventions, case-based distancing (self-isolation, quarantine), and restriction of mobility and mass gatherings. School closure, whether proactive or reactive, appears to be moderately effective and acceptable in reducing the transmission of influenza and in delaying the peak of an epidemic but is associated with very high secondary costs. Voluntary home isolation and quarantine are also effective and acceptable measures but there is an increased risk of intra-household transmission from index cases to contacts. Work place-related interventions like work closure and home working are also modestly effective and are acceptable, but likely to be economically disruptive. Internal mobility restriction is effective only if prohibitively high (50% of travel) restrictions are applied and mass gatherings occurring within 10 days before the epidemic peak are likely to increase the risk of transmission of influenza. PMID:24630149

  19. Avian Influenza A Virus Infections in Humans

    Science.gov (United States)

    ... Past Newsletters Avian Influenza A Virus Infections in Humans Language: English Español Recommend on Facebook Tweet ... A Viruses Avian Influenza A Virus Infections in Humans Although avian influenza A viruses usually do not ...

  20. Lattice model for influenza spreading with spontaneous behavioral changes.

    Directory of Open Access Journals (Sweden)

    Annalisa Fierro

    Full Text Available Individual behavioral response to the spreading of an epidemic plays a crucial role in the progression of the epidemic itself. The risk perception induces individuals to adopt a protective behavior, as for instance reducing their social contacts, adopting more restrictive hygienic measures or undergoing prophylaxis procedures. In this paper, starting with a previously developed lattice-gas SIR model, we construct a coupled behavior-disease model for influenza spreading with spontaneous behavioral changes. The focus is on self-initiated behavioral changes that alter the susceptibility to the disease, without altering the contact patterns among individuals. Three different mechanisms of awareness spreading are analyzed: the local spreading due to the presence in the neighborhood of infective individuals; the global spreading due to the news published by the mass media and to educational campaigns implemented at institutional level; the local spreading occurring through the "thought contagion" among aware and unaware individuals. The peculiarity of the present approach is that the awareness spreading model is calibrated on available data on awareness and concern of the population about the risk of contagion. In particular, the model is validated against the A(H1N1 epidemic outbreak in Italy during the 2009/2010 season, by making use of the awareness data gathered by the behavioral risk factor surveillance system (PASSI. We find that, increasing the accordance between the simulated awareness spreading and the PASSI data on risk perception, the agreement between simulated and experimental epidemiological data improves as well. Furthermore, we show that, within our model, the primary mechanism to reproduce a realistic evolution of the awareness during an epidemic, is the one due to globally available information. This result highlights how crucial is the role of mass media and educational campaigns in influencing the epidemic spreading of infectious