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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A Spatial Statistical Analysis to Estimate the Spatial Dynamics of the 2009 H1N1 Pandemic in the Greater Toronto Area

Fan, WENYONG 05 November 2012 (has links)
The 2009 H1N1 pandemic caused serious concerns worldwide due to the novel biological feature of the virus strain, and the high morbidity rate for youth. The urban scale is crucial for analyzing the pandemic in metropolitan areas such as the Greater Toronto Area (GTA) of Canada because of its large population. The challenge of exploring the spatial dynamics of H1N1 is exaggerated by data scarcity and the absence of an immediately applicable methodology at such a scale. In this study, a stepwise methodology is developed, and a retrospective spatial statistical analysis is conducted using the methodology to estimate the spatial dynamics of the 2009 H1N1 pandemic in the GTA when the data scarcity exists. The global and local spatial autocorrelation analyses are carried out through the use of multiple spatial analysis tools to confirm the existence and significance of spatial clustering effects. A Generalized Linear Mixed Model (GLMM) implemented in Statistical Analysis System (SAS) is used to estimate the area-specific spatial dynamics. The GLMM is configured to a spatial model that incorporates an Intrinsic Gaussian Conditionally Autoregressive (ICAR) model, and a non-spatial model respectively. Comparing the results of spatial and non-spatial configurations of the GLMM suggests that the spatial GLMM, which incorporates the ICAR model, proves a better predictability. This indicates that the methodology developed in this study can be applied to epidemiology studies to analyze the spatial dynamics in similar scenarios. / Thesis (Master, Geography) -- Queen's University, 2012-10-30 17:41:28.445
2

EPIDEMIA DA INFLUENZA A (H1N1) 2009 NO ESTADO DE GOIÁS/BRASIL: CASOS E ÓBITOS

Siqueira, Giselle Angélica Moreira de 19 December 2013 (has links)
Submitted by admin tede (tede@pucgoias.edu.br) on 2018-11-19T16:59:56Z No. of bitstreams: 1 GISELLE ANGÉLICA MOREIRA DE SIQUEIRA.pdf: 1650143 bytes, checksum: 0a85747b640c1ee6d3c2dc446dececf7 (MD5) / Made available in DSpace on 2018-11-19T16:59:56Z (GMT). No. of bitstreams: 1 GISELLE ANGÉLICA MOREIRA DE SIQUEIRA.pdf: 1650143 bytes, checksum: 0a85747b640c1ee6d3c2dc446dececf7 (MD5) Previous issue date: 2013-12-19 / SIQUEIRA, Giselle Angelica Moreira de. Epidemic Influenza A (H1N1) 2009 in the state of Goiás/Brazil: cases and deaths. Dissertation (MSc in Environmental Sciences) – Catholic University of Goiás, Goiânia, 2013. Between late March and early April 2009, were the first reported cases of human infection caused by a new viral subtype Influenza A (H1N1) in Southern California and near San Antonio, Texas, USA, and then in Mexico and Canada. Until July 6, 2009, 905 cases were confirmed by the Ministry of Health, with reports of 23 states and the Federal District. This study described the profile of confirmed cases and deaths affected by Influenza A ( H1N1 ) in 2009 in the state of Goias and Brazil through a descriptive ecological study of confirmed cases and deaths affected by Influenza A virus (H1N1) 2009 in the State of Goias and Brazil between epidemiological weeks 16 th to 52 th, variables of research Influenza record, feeding SINAN Influenza Web were selected such as epidemiological week, age, gender, education, signs and symptoms, comorbidities, vaccination status, hospitalizations and evolution. Among the total number of cases reported during the epidemic , more than 45% were confirmed Influenza A (H1N1) in Goiás and in Brazil , with 14.9% and 3.9% subsequently died respectively. Females were predominant, those over 6 % were pregnant. The age range was found between 15 and 45 years, with the primary and secondary school levels observed schooling. Among the signs and symptoms , more than 95% of cases and deaths had fever, cough and dyspnoea, less than 30% had comorbid conditions, the occurrence of hospitalizations of cases was 96% and 45% in Goiás in Brazil, while hospitalization those who subsequently died was above 96%, less than 14% of cases and deaths have taken the vaccine against influenza (H1N1). It was concluded that it was possible to know the profile of cases and deaths from socio demographic and clinical characteristics during the epidemic period Influenza (H1N1) 2009 in Goias and Brazil, many lessons were learned that will assist in the consolidation of plans to tackle the unusual situations of epidemic and pandemic character and guide the development of public policies that will strengthen the surveillance system of disease, health care, implementation of laboratory diagnosis, mass vaccination and personal protection and respiratory hygiene network. / SIQUEIRA, Giselle Angélica Moreira de. Epidemia da Influenza A (H1N1) 2009 no estado de Goiás/Brasil: casos e óbitos. Dissertação (Mestrado em Ciências Ambientais) – Pontifícia Universidade Católica de Goiás, Goiânia, 2013. Entre o final de março e começo de abril de 2009, foram notificados os primeiros casos de infecção humana causada por um novo subtipo viral Influenza A (H1N1), no sul da Califórnia e próximo de San Antonio, no Texas, Estados Unidos, e, em seguida, no México e Canadá. Até o dia 06 de julho de 2009, 905 casos foram confirmados pelo Ministério da Saúde, com notificações de 23 estados e do Distrito Federal. Neste estudo foi descrito o perfil dos casos confirmados e óbitos acometidos por Influenza A (H1N1) em 2009 no Estado de Goiás e Brasil por meio de um estudo ecológico descritivo dos casos confirmados e óbitos acometidos pelo vírus Influenza A (H1N1) 2009 no Estado de Goiás e Brasil entre as semanas epidemiológicas 16ª a 52ª, foram selecionadas variáveis da ficha de investigação de Influenza, que alimenta o SINAN Influenza Web tais como semana epidemiológica, faixa etária, gênero, escolaridade, sinais e sintomas, comorbidades, situação vacinal, hospitalizações e evolução. Dentre o total de casos notificados durante a epidemia, mais de 45% foram confirmados por Influenza A (H1N1) em Goiás e no Brasil, sendo que 14,9% e 3,9% evoluíram para o óbito respectivamente. O gênero feminino foi predominante, destas mais de 6% eram gestantes. A faixa etária encontrada foi entre 15 a 45 anos, sendo o ensino médio e fundamental os níveis de escolaridade constatados. Dentre os sinais e sintomas, mais de 95% dos casos e óbitos apresentaram febre, tosse e dispneia, menos de 30% apresentaram comorbidades, a ocorrência de hospitalizações dos casos foi de 96 % em Goiás e 45% no Brasil, enquanto que a hospitalização dos que evoluíram para o óbito foi acima de 96%, menos de 14% dos casos e óbitos tomaram a vacina contra a Influenza (H1N1). Concluiu-se que foi possível conhecer o perfil de casos e óbitos a partir das características sócio demográficas e clínicas durante o período epidêmico da Influenza (H1N1) 2009 em Goiás e no Brasil, foram aprendidas muitas lições que auxiliarão na consolidação de planos de enfrentamento a situações inusitadas de caráter epidêmico e pandêmico e norteará a construção de políticas públicas que fortalecerá o sistema de vigilância da doença, da rede de atenção à saúde, implementação de diagnóstico laboratorial, vacinação massiva e medidas de proteção individual e higiene respiratória.
3

Analyse d'un grand jeu de données en épidémiologie : problématiques et perspectives méthodologiques / Analysis of a large dataset in epidemiology : issues and methodological perspectives

Mansiaux, Yohann 30 October 2014 (has links)
L'augmentation de la taille des jeux de données est une problématique croissante en épidémiologie. La cohorte CoPanFlu-France (1450 sujets), proposant une étude du risque d'infection par la grippe H1N1pdm comme une combinaison de facteurs très divers en est un exemple. Les méthodes statistiques usuelles (e.g. les régressions) pour explorer des associations sont limitées dans ce contexte. Nous comparons l'apport de méthodes exploratoires data-driven à celui de méthodes hypothesis-driven.Une première approche data-driven a été utilisée, évaluant la capacité à détecter des facteurs de l'infection de deux méthodes de data mining, les forêts aléatoires et les arbres de régression boostés, de la méthodologie " régressions univariées/régression multivariée" et de la régression logistique LASSO, effectuant une sélection des variables importantes. Une approche par simulation a permis d'évaluer les taux de vrais et de faux positifs de ces méthodes. Nous avons ensuite réalisé une étude causale hypothesis-driven du risque d'infection, avec un modèle d'équations structurelles (SEM) à variables latentes, pour étudier des facteurs très divers, leur impact relatif sur l'infection ainsi que leurs relations éventuelles. Cette thèse montre la nécessité de considérer de nouvelles approches statistiques pour l'analyse des grands jeux de données en épidémiologie. Le data mining et le LASSO sont des alternatives crédibles aux outils conventionnels pour la recherche d'associations. Les SEM permettent l'intégration de variables décrivant différentes dimensions et la modélisation explicite de leurs relations, et sont dès lors d'un intérêt majeur dans une étude multidisciplinaire comme CoPanFlu. / The increasing size of datasets is a growing issue in epidemiology. The CoPanFlu-France cohort(1450 subjects), intended to study H1N1 pandemic influenza infection risk as a combination of biolo-gical, environmental, socio-demographic and behavioral factors, and in which hundreds of covariatesare collected for each patient, is a good example. The statistical methods usually employed to exploreassociations have many limits in this context. We compare the contribution of data-driven exploratorymethods, assuming the absence of a priori hypotheses, to hypothesis-driven methods, requiring thedevelopment of preliminary hypotheses.Firstly a data-driven study is presented, assessing the ability to detect influenza infection determi-nants of two data mining methods, the random forests (RF) and the boosted regression trees (BRT), ofthe conventional logistic regression framework (Univariate Followed by Multivariate Logistic Regres-sion - UFMLR) and of the Least Absolute Shrinkage and Selection Operator (LASSO), with penaltyin multivariate logistic regression to achieve a sparse selection of covariates. A simulation approachwas used to estimate the True (TPR) and False (FPR) Positive Rates associated with these methods.Between three and twenty-four determinants of infection were identified, the pre-epidemic antibodytiter being the unique covariate selected with all methods. The mean TPR were the highest for RF(85%) and BRT (80%), followed by the LASSO (up to 78%), while the UFMLR methodology wasinefficient (below 50%). A slight increase of alpha risk (mean FPR up to 9%) was observed for logisticregression-based models, LASSO included, while the mean FPR was 4% for the data-mining methods.Secondly, we propose a hypothesis-driven causal analysis of the infection risk, with a structural-equation model (SEM). We exploited the SEM specificity of modeling latent variables to study verydiverse factors, their relative impact on the infection, as well as their eventual relationships. Only thelatent variables describing host susceptibility (modeled by the pre-epidemic antibody titer) and com-pliance with preventive behaviors were directly associated with infection. The behavioral factors des-cribing risk perception and preventive measures perception positively influenced compliance with pre-ventive behaviors. The intensity (number and duration) of social contacts was not associated with theinfection.This thesis shows the necessity of considering novel statistical approaches for the analysis of largedatasets in epidemiology. Data mining and LASSO are credible alternatives to the tools generally usedto explore associations with a high number of variables. SEM allows the integration of variables des-cribing diverse dimensions and the explicit modeling of their relationships ; these models are thereforeof major interest in a multidisciplinary study as CoPanFlu.
4

Étude sur les déterminants psychosociaux de la vaccination contre le virus A(H1N1) auprès des parents d’enfants qui fréquentent des services de garde éducatifs de Montréal

Langlois, Mathieu 12 1900 (has links)
Introduction En juin 2009, l’Organisation Mondiale de la Santé (OMS) a déclaré l’état de pandémie pour le nouveau virus influenza A(H1N1). Malgré les recommandations des autorités de santé publique, lors de la mise en place de la campagne de vaccination de masse au Québec contre ce virus pandémique, certains groupes de la population ont été plus enclins à être vaccinés que d’autres groupes. Ceci souligne l’importance des déterminants psychosociaux du comportement humain, sujet qui a donné cadre à notre étude. Objectifs Le but de cette étude a été de documenter les attitudes, les connaissances et les influences sociales des parents dont les enfants fréquentent des services de garde éducatifs (SGE) vis-à-vis la vaccination contre la pandémie ainsi que la couverture vaccinale. Méthodologie Un questionnaire auto-administré et anonyme basé sur la théorie des comportements interpersonnels de Triandis a été distribué aux parents d’enfants âgés de 0-59 mois de neuf centres de la petite enfance sur l’île de Montréal. Résultats Le taux de réponse de l’enquête a été de 32,0% (N=185). Le taux de vaccination des enfants s’est retrouvé à 83,4%; ceci représente une couverture plus élevée que la moyenne régionale et nationale. Toutefois, à une question sur l’intention des parents face à une autre pandémie, seuls 46% des parents feraient vacciner leur enfant. Les facteurs les plus significatifs associés à la vaccination de leur enfant ont été les croyances personnelles positives, de bonnes habitudes vaccinales et l’influence des média, tous mesurés par plusieurs indicateurs (RC respectifs de 7,7, 3,1 et 4,2, p<0,05). Conclusion Pour la grippe A(H1N1), plusieurs facteurs contextuels ont joué en faveur des taux de vaccination acceptables chez les enfants. Toutefois, la mise en place d’une campagne de la vaccination par les instances gouvernementales et de santé publique en utilisant divers média pourraient contribuer à un taux de vaccination encore plus élevé en cas d’épidémie ou de pandémie. / Background In June 2009, the World Health Organization (WHO) declared the 2009 A(H1N1) swine flu a pandemic. Despite the recommandations from public health authorities when setting up the mass immunization campaign in Quebec against the influenza A(H1N1), some population groups were more likely to be vaccinated than others. This underlines the importance of psychosocial determinants of human behaviour, which gave a framework for our study. Objectives The aim of this study was to document the attitudes, knowledge and social influences of parents whose children attend early childhood centers (ECC) regarding the vaccination against the pandemic and its coverage. Methods A self-administered and anonymous questionnaire based on the theory of reasoned action of Triandis was distributed to parents of children aged 0-59 months in nine childcare centers on the island of Montreal. Results The response rate of the survey was 32.0% (N=185). The vaccination uptake for children was 84%; this represents a higher coverage than the average regional and national levels. However, only 46% of the parents said that they would vaccinate their child again if a new flu pandemic was being declared by the World Health Organization. The most significant factors associated with vaccination uptake were positive personal beliefs, getting seasonal flu vaccines and the influence of media, all measured by several indicators (respective odds ratio 7,7, 3,1 and 4,2, p<0,05). Conclusion Several contextual factors played in favour of acceptable vaccination rates among children. However, the establishment of a campaign of vaccination by government authorities and public health agencies while using various media to spread information could contribute to higher vaccination rates in a future case of epidemic or pandemic.
5

Characterization of H1N2 variant influenza viruses in pigs

Duff, Michael Alan January 1900 (has links)
Master of Science / Department of Diagnostic Medicine/Pathobiology / Wenjun Ma / With introduction of the 2009 pandemic H1N1 virus (pH1N1) into swine herds, reassortment between the pH1N1 and endemic swine influenza viruses (SIVs) has been reported worldwide. Recently, reassortant H3N2 and H1N2 variant SIVs that contain the M gene from pH1N1 virus and the remaining seven genes from North American triple-reassortant (TR) SIVs have emerged. These variant viruses have caused more than 300 cases of human infections and one death in the USA, creating a major public health concern. To date, the pathogenicity and transmissibility of H1N2 variant viruses in pigs has not been investigated. Through passive surveillance, we have isolated two genotypes of reassortant H1N2 viruses with pH1N1 genes from diseased pigs in Kansas. Full genome sequence and phylogenetic analysis showed that one is a swine H1N2 variant virus (swH1N2v) with the M gene from pH1N1; the other is a reassortant H1N2 virus (2+6 rH1N2) with six internal genes from pH1N1 and the two surface genes from endemic North American TR H1N2 SIVs. Furthermore, we determined the pathogenicity and transmissibility of the swH1N2v, a human H1N2 variant (huH1N2v), and the 2+6 rH1N2 in pigs using an endemic TR H1N2 SIV (eH1N2) isolated in 2011 as a control. All four viruses were able to infect pigs and replicate in the lungs. Both H1N2 variant viruses caused more severe lung lesions in infected pigs when compared to the eH1N2 and 2+6 rH1N2 viruses. Although all four viruses are transmissible in pigs and were detected in the lungs of contact animals, the swH1N2v shed more efficiently than the other three viruses in the respective sentinel animals. The huH1N2v displayed delayed and inefficient nasal shedding in sentinel animals. Taken together, the human and swine H1N2 variant viruses are more pathogenic and the swH1N2v more transmissible in pigs and could pose a threat to public and animal health.
6

Étude sur les déterminants psychosociaux de la vaccination contre le virus A(H1N1) auprès des parents d’enfants qui fréquentent des services de garde éducatifs de Montréal

Langlois, Mathieu 12 1900 (has links)
Introduction En juin 2009, l’Organisation Mondiale de la Santé (OMS) a déclaré l’état de pandémie pour le nouveau virus influenza A(H1N1). Malgré les recommandations des autorités de santé publique, lors de la mise en place de la campagne de vaccination de masse au Québec contre ce virus pandémique, certains groupes de la population ont été plus enclins à être vaccinés que d’autres groupes. Ceci souligne l’importance des déterminants psychosociaux du comportement humain, sujet qui a donné cadre à notre étude. Objectifs Le but de cette étude a été de documenter les attitudes, les connaissances et les influences sociales des parents dont les enfants fréquentent des services de garde éducatifs (SGE) vis-à-vis la vaccination contre la pandémie ainsi que la couverture vaccinale. Méthodologie Un questionnaire auto-administré et anonyme basé sur la théorie des comportements interpersonnels de Triandis a été distribué aux parents d’enfants âgés de 0-59 mois de neuf centres de la petite enfance sur l’île de Montréal. Résultats Le taux de réponse de l’enquête a été de 32,0% (N=185). Le taux de vaccination des enfants s’est retrouvé à 83,4%; ceci représente une couverture plus élevée que la moyenne régionale et nationale. Toutefois, à une question sur l’intention des parents face à une autre pandémie, seuls 46% des parents feraient vacciner leur enfant. Les facteurs les plus significatifs associés à la vaccination de leur enfant ont été les croyances personnelles positives, de bonnes habitudes vaccinales et l’influence des média, tous mesurés par plusieurs indicateurs (RC respectifs de 7,7, 3,1 et 4,2, p<0,05). Conclusion Pour la grippe A(H1N1), plusieurs facteurs contextuels ont joué en faveur des taux de vaccination acceptables chez les enfants. Toutefois, la mise en place d’une campagne de la vaccination par les instances gouvernementales et de santé publique en utilisant divers média pourraient contribuer à un taux de vaccination encore plus élevé en cas d’épidémie ou de pandémie. / Background In June 2009, the World Health Organization (WHO) declared the 2009 A(H1N1) swine flu a pandemic. Despite the recommandations from public health authorities when setting up the mass immunization campaign in Quebec against the influenza A(H1N1), some population groups were more likely to be vaccinated than others. This underlines the importance of psychosocial determinants of human behaviour, which gave a framework for our study. Objectives The aim of this study was to document the attitudes, knowledge and social influences of parents whose children attend early childhood centers (ECC) regarding the vaccination against the pandemic and its coverage. Methods A self-administered and anonymous questionnaire based on the theory of reasoned action of Triandis was distributed to parents of children aged 0-59 months in nine childcare centers on the island of Montreal. Results The response rate of the survey was 32.0% (N=185). The vaccination uptake for children was 84%; this represents a higher coverage than the average regional and national levels. However, only 46% of the parents said that they would vaccinate their child again if a new flu pandemic was being declared by the World Health Organization. The most significant factors associated with vaccination uptake were positive personal beliefs, getting seasonal flu vaccines and the influence of media, all measured by several indicators (respective odds ratio 7,7, 3,1 and 4,2, p<0,05). Conclusion Several contextual factors played in favour of acceptable vaccination rates among children. However, the establishment of a campaign of vaccination by government authorities and public health agencies while using various media to spread information could contribute to higher vaccination rates in a future case of epidemic or pandemic.
7

Aktivitetsvanor, stillasittande och tilltro till egen förmåga att klara fysisk aktivitet hos personer som drabbats av narkolepsi i samband med Pandemrix-vaccinationen år 2009

Skärdin, Julia January 2018 (has links)
Bakgrund: Efter Pandemrix-vaccinationen år 2009 i Sverige insjuknade ett stort antal unga individer i den koniska sjukdomen narkolepsi. Syfte: Kartlägga aktivitetsvanor, stillasittande, tilltro till egen förmåga att klara fysisk aktivitet samt undersöka samband mellan aktivitetsnivå och tilltro till egen förmåga att klara fysisk aktivitet. Metod: Undersökningsgruppen var 120 individer över 18 år, från Narkolepsiföreningen, som drabbats i samband med Pandemrix-vaccinationen år 2009. Datainsamling genomfördes via enkät.   Resultat: 47,1 procent uppnådde WHO:s rekommenderade aktivitetsnivå. 25,2 procent var fysiskt aktiva mindre än en gång i månaden eller aldrig. Genomsnittlig stillasittandetid var sju timmar och nio minuter/dag. Medianen för tilltro till egen förmåga att klara fysisk aktivitet var 19 på en skala mellan 9-36. Ett signifikant måttligt samband mellan tilltro till egen förmåga att klara fysisk aktivitet och aktivitetsnivå förelåg. Konklusion: Studiens resultat talar för att narkolepsidrabbade bör öka sin aktivitetsnivå och för att uppnå det även öka tilltro till egen förmåga att klara fysisk aktivitet. / Backgroud: After the Pandemrix-vaccination in 2009 a sudden increase in childhood narcolepsy was observed in Sweden. Scientific research focusing on the level of physical activity within this group is scarce. Purpose: Identifying the level of physical activity and physical exercise, sedentary behavior, self-efficacy to perform physical activity, as well as examine the correlation between physical activity level and self-efficacy to perform physical activity. Method: 120 individuals, over 18 years of age, who developed narcolepsy due to the Pandemrix-vaccination and were members of the Swedish Narcolepsy Association participated in the study. The data collection was conducted through a survey. Results: 47.1 percent of the participants achieved the WHO recommendations for physical activity. 25.2 percent were physically active less than once a month or never. The duration of the participants average time of sedentary behavior was seven hours and nine minutes per day. The median for self-efficacy to perform physical activity was 19 on a scale between 9-36. There was a significant moderate correlation between the participants self-efficacy to perform physical activity and their level of physical activity . Conclusion: The results of this study indicates that individuals suffering from narcolepsy should increase their level of physical activity as well as increase their self-efficacy to perform physical activity.

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