This study evaluates the ecology of Streptococcus pneumoniae (SP) nasopharynx (NP) colonization in response to the pneumococcal conjugate vaccines, specifically 7-Valent Pneumococcal Conjugate Vaccine (2000-2009), 13-Valent Pneumococcal Conjugate Vaccine (2010-2023) and 20-Valent Pneumococcal Conjugate Vaccine (2023-future date). It is anticipated that the replacement of PCV13 with PCV20, a pneumococcal conjugate vaccine with 7 additional polysaccharide conjugates to CRM197 will enhance the protection against non-vaccine serotypes which are in circulation in communities. The project will evaluate the dynamic changes in pneumococcal colonization over the 5-year time line from 2021-2026. Pneumococcal nasopharynx colonization is detected through nasopharyngeal culture and molecular techniques. The primary source of pneumococcal transmission occurs among the pediatric population and between children and adults. The impact of PCV7 and 13 on pneumococcal colonization over the prior 20 years created a herd effect that resulted in a reduction in pneumococcal disease in unimmunized children and adults. Studies of NP colonization has led to a deeper understanding of pneumococcal conjugate vaccine (PCV) effectiveness and the role of herd immunity in protecting the population, the emergence of replacement serotypes, the variation in invasive capability of each serotype and evolution of antimicrobial resistance resulting from the evolving ecology. In this 5-year-study, researchers at the Pelton Lab in Boston Medical Center set out to understand the prevalence of NP carriage of 13vPnC serotypes, the 7 unique 20vPnC serotypes and NVST (non-vaccine serotypes) within the pediatric population prior to and subsequent to the introduction of PCV 20 (Fall 2023).

Formalized epidemiological field investigations were conducted to compare and contrast the transmission dynamics of EHV-1 neurological disease among horses stabled at Churchill Downs Racetrack, Louisville, Kentucky and of EHV-1 respiratory illness among horses stabled in the student barn at Murray State University. Differences were assessed by means of statistical and mathematical modeling techniques applied to survey and biological data collected over the course of the respective disease events. Regression methods applied to survey data enabled the construction of a statistical model to predict a date of onset of illness for horses within each equine cohort. Comparisons of the epidemic curves revealed that the Murray State University outbreak was 4.5 times longer (9 weeks versus 14 days) than the Churchill Downs Racetrack event. Survival analysis was used to explore the relationship between time to infection for each equine cohort. Horses stabled in the affected barn at Churchill Downs racetrack had a 3.02 times greater daily risk (p < 0.001) for contracting EHV-1 infection relative to horses stabled in the student barn at Murray State University. Estimates of the basic R0 number, calculated using mathematical formulae that incorporated the duration of the infectious period for neuropathogenic and nonneuropathogenic strains of EHV-1, were 10.25 and 2.94 for the Churchill Downs racetrack and Murray State University outbreaks, respectively. The generation time for the Churchill Downs outbreak was 6.1 times shorter (0.39 days versus 2.38 days) than for the Murray State University event. An assessment of the temporal occurrence of symptomatic infection is similar for each event and suggests that the appearance of clinical illness is constant over the course of an outbreak. A Reed-Frost model was constructed for each EHV-1 event where values of the transmission parameters (q, p and k) were estimated by fitting a model that most closely matched the observed profile of EHV-1 cases. The value of prophylactic vaccination on the spread of EHV-1 was assessed by making adjustments to these fitted models for varying levels of herd immunity. The results indicate that the prevention of EHV-1 neurological illness requires a higher level of herd immunity than EHV-1 respiratory illness.

All wildlife populations harbour parasites. However, seabirds are likely to play a particularly important role in the maintenance and dispersal of infectious agents as a result of their colonial breeding habits. Seabird colonies are also known to be highly spatially structured, but little is known about the effects of this spatial structuring on seabird parasite dynamics. In this thesis, I use a tick-borne virus, Great Island virus (GIV), found in a large common guillemot (Uria aalge) colony bordering the North Sea as a model system to explore this relationship. I use a multidisciplinary approach, framed by a simple epidemiological model of the guillemot-tick-virus system. In Chapter 2, I describe a novel epidemiological model and parameterise it using the existing literature. The model suggests the importance of spatial structure within the guillemot colony, but also identifies a key missing parameter, the rate of virus transmission between pre-breeding and breeding areas. In Chapter 3, I go on to test the potential role of independent tick movement in driving transmission between these two areas, by quantifying the mobility of host-seeking seabird ticks, Ixodes uriae. I show the potential for ticks to walk ranges described anecdotally in the literature, in just a few minutes, but stress the importance of further experiments in the field. Chapter 4, I test the potential role of guillemot-mediated tick movement between pre-breeding and breeding areas. I show that pre-breeding guillemots spend a limited proportion of time ashore during daylight hours, which increases significantly as the season progresses and varies between individuals. A similar pattern is observed when considering how often they enter breeding areas when ashore; generally infrequently but varying spatiotemporally and between individuals. In Chapter 5, I apply finite mixture modelling techniques to improve existing estimates of age- and strain-specific GIV seroprevalence and force of infection in the guillemot colony. I also provide the first estimates of these parameters for eight strains, and highlight the importance of understanding strain-specific differences in GIV dynamics in future studies. Finally, I bring all four data chapters together in Chapter 6, by inputting my new parameter estimates (Chapters 3-5) into my existing model (Chapter 2). Taken together, my results suggest that GIV transmission within the guillemot colony may increase in the future as a result of declining breeding abundance and success, with more frequent or extreme disruption leading to a higher risk of infection within the colony. More generally, my results suggest that seabird colonies can be highly sensitive to changes in their spatial structure, and that endemic parasites have the potential to substantially impact, and hence to be an added threat to, their seabird hosts.

To understand how plant defensive traits will evolve, we need to consider the biotic context for plant-herbivore interactions. I investigated how predators affect selection on defensive traits in plants. First, I established the timing of resistance in three soybean genotypes. Next, I examined the combined effects of resistance and predators on plant fitness. I reared Mexican bean beetles (MBBs) with or without spined soldier bugs (SSBs) on soybeans with constitutive resistance (CR) or no resistance (NR). SSBs fed more on MBBs that fed on NR than on CR plants, and this translated into an increased fitness benefit from predators for NR plants over CR plants. Selection for some types of resistance in plants should thus be stronger with lower predation rates. Similarly, I reared MBBs with or without SSBs on soybeans with early induced resistance (EI), late induced resistance (LI), or CR. SSBs fed more on MBBs reared on LI plants than on beetles raised on CR plants, but no more on beetles reared on EI plants than on beetles reared on CR plants. LI plants were the only of the three soybean varieties to receive a fitness benefit from predators, which could help explain the evolution of this type of plant defense. The results of both experiments also suggest that predator introductions may be more beneficial to LI or NR crop plants than EI or CR crops. Finally, I present a model that determines the optimum amount of induced resistance (IR) and CR for a plant growing with and without neighbors. Unlike earlier models, our plants have a probability of being attacked that is modified by short- and long-term feedback of plant defenses to herbivores. Higher costs of defense favor IR over CR, while increasing herbivore attack rates or increasing the overall effectiveness of defense results in more CR. Plants with neighbors might be selected to evolve higher or lower levels of CR than if they were growing alone. Adding neighbors also selects for more mixed induced/constitutive strategies for all parameters. Having defended neighbors could thus be part of the reason why plants have evolved such mixed defense strategies. / Dissertation

Background: To achieve control of a vaccine preventable communicable disease, it is of importance to establish high enough coverage to reach the threshold for herd immunity.  Preventive public health interventions, such as vaccination programmes, create dilemmas between societal versus individual benefits of the programme. Vaccine providers handle this dilemma when motivating hesitant parents and vaccine providers´ own perceptions of vaccine benefits will possibly influence the parental decision. The motivating strategies need to support parental autonomy, the best interest of the child and societal benefits. By using the bioethical principles autonomy, beneficence and justice, strategies can be analyzed regarding what agents are most benefitted by the strategy. Purpose: To gain insight in how vaccine providers balance between individual, societal, parental and internal values when promoting vaccine towards vaccine hesitant parents. Method:  Explorative qualitative interview study. Results: The respondents´ strategies are more or less influencing and adjusted according to the underlying reason the parents have for hesitation. An underlying strategy is to use means of social interaction to build trustful relationships. Respondents perceived reasons to vaccinate are ranging from individual to societal and are reflected in the strategies and the respondents aim to aid parents to a well informed decision. Some strategies are more persuasive than others and in rare occasions infringe on parental autonomy in a less plausible manner. Conclusions: The findings from this study reflect that the public health dilemma is indeed present in the clinical context when motivating vaccine hesitant parents. Respondents do their utmost to aid the parents to a well informed decision, regardless if the child will be vaccinated or not, or whatever reason parents have for hesitance. Since vaccination  is a voluntary action that is required from many to reach herd immunity, vaccine providers need to consider the ethics surrounding motivating hesitant parents to reach best possible outcome regardless if  this is benefitting the child, society or parental autonomy / Bakgrund: För att kunna kontrollera vaccinerbara smittsamma sjukdomar är det av högsta vikt att etablera hög vaccintäckning och uppnå nivån för flockimmunitet. Preventiva folkhälsointerventioner, såsom vaccinationsprogram, skapar dilemman mellan samhällelig och individnytta. Yrkespersoner som erbjuder vaccin måste hantera detta dilemma när de motiverar föräldrar som är tveksamma till att vaccinera sina barn. Yrkespersonernas uppfattningar om nyttan med vacciner och motivationsstrategierna kan tänkas påverka föräldrarnas beslut. Strategierna behöver stödja såväl föräldrarnas autonomi, barnets rätt och samhällets bästa. Genom användande av de bioetiska principerna autonomi, godhet och rättvisa kan strategierna analyseras utifrån vilka agenter som gagnas mest. Syfte: Att få inblick i hur yrkespersoners balanserar mellan individuella, samhälleliga, föräldrarelaterade och interna värden när de promotar vaccin till föräldrar som är tveksamma till vaccin. Metod: Explorativ kvalitativ intervjustudie. Resultat: Respondenternas strategier anpassas efter föräldrarnas bakomliggande skäl till att inte vaccinera sina barn och är mer eller mindre influerande. En underliggande strategi är att använda social interaktion för att bygga förtroende hos föräldrarna. Respondenterna uppfattade nyttan med vacciner som både individuell och samhällelig och speglades i strategierna. Respondenterna siktade på att föräldrarnas beslut ska vara välgrundat. Några strategier är mer övertalande än andra och i sällsynta fall inkräktande på föräldrarnas autonomi på ett mindre lämpligt sätt. Slutsats: Fynden speglar att folkhälsodilemmat mellan individ och samhälle är närvarande i den kliniska situationen när tveksamma föräldrar ska motiveras till att vaccinera sina barn. Respondenterna gör sitt yttersta för att guida föräldrarna till ett välgrundat beslut, oavsett om barnet blir vaccinerat eller inte, oavsett vilket skäl föräldrarna har till tveksamheten. Eftersom att vaccination är en frivillig handling som krävs av många för att uppnå flockimmunitet så behöver yrkespersoner ta hänsyn till etiken kring när föräldrar motiveras till att vaccinera sina barn. Detta för att uppnå bästa möjliga resultat oavsett om det gagnar barnet, samhället eller föräldrarnas autonomi.

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Le travail présenté dans ce manuscrit traite des mécanismes d'émergence des maladies infectieuses. Une première partie du texte est consacrée à la réflexion menée sur ces processus, et à leurs conséquences pour la gestion des maladies. Dans une deuxième partie nous exposons les travaux de modélisation réalisés ; l’objectif est de tester si des changements dans l'expression d'une infection peuvent être expliqués par la dynamique de circulation de l'agent infectieux dans la population hôte, à travers la protection de groupe. Nous montrons que l'apparition de la maladie de Carré chez les lions du Serengeti peut être due à une perte d’immunité de groupe suite à l’extinction du virus. Nous étudions ensuite les conséquences sur le patron épidémique d'une protection partiellement croisée entre souches. Enfin, nous intégrons à cette problématique la structure spatiale de la population hôte, pour expliquer des observations faites sur les systèmes lagomorphes/lagovirus en France. / The study presented here aims to suggest and to test several mechanisms to explain how infectious diseases impact could increase, in relation to microparasite circulation and loss of herd protection. We first introduce the main characteristics of host/microparasite interaction and display some knowledge about emerging infectious diseases, and their consequences for diseases control. Stochastic modelling is then used to study epidemic patterns under several hypotheses and for different host/parasite systems: i) we explain canine distemper emergence in Serengeti lions through a break in virus circulation and the resulting loss of herd immunity; ii) we study the consequences of partial crossprotection induced in hosts by different strains in a small homogeneous host population; and iii) we extend this study to spatially structured host populations to explain data observed in lagomorphs/lagoviruses in France.

Cette thèse propose une étude mathématique des stratégies de vaccination.La partie I présente le cadre mathématique, notamment le modèle à compartiments Susceptible - Infected – Recovered.La partie II aborde les techniques mathématiques de type contrôle optimal employées afin de trouver une stratégie optimale de vaccination au niveau de la société. Ceci se fait en minimisant le coût de la société. Nous montrons que la fonction valeur associée peut avoir une régularité plus faible que celle attendue dans la littérature. Enfin, nous appliquons les résultats à la vaccination contre la coqueluche.La partie III présente un modèle où le coût est défini au niveau de l'individu. Nous reformulons le problème comme un équilibre de Nash et comparons le coût obtenu avec celui de la stratégie sociétale. Une application à la grippe A(H1N1) indique la présence de perceptions différentes liées à la vaccination.La partie IV propose une implémentation numérique directe des stratégies présentées. / This thesis propose a mathematical analysis of the vaccination strategies.The first part introduces the mathematical framework, in particular the Susceptible – Infected – Recovered compartmental model.The second part introduces the optimal control tools used to find an optimal vaccination strategy from the societal point of view, which is a minimizer of the societal cost. We show that the associated value function can have a less regularity than what was assumed in the literature. These results are then applied to the vaccination against the whooping cough.The third part defines a model where the cost is defined at the level of the individual. We rephrase this problem as a Nash equilibrium and compare this results with the societal strategy. An application to the Influenza A(H1N1) 2009-10 indicates the presence of inhomogeneous perceptions concerning the vaccination risks.The fourth and last part proposes a direct numerical implementation of the different strategies.

Tesis por compendio / [ES] El brote de Coronavirus SARS-CoV-2 representó un reto para la economía, la vida social y los servicios sanitarios. Justo cuando más se necesitaba la información para la planificación económica, los servicios de vigilancia y notificación no fueron capaces de ofrecer, a pesar de esfuerzos extraordinarios, datos consistentes, como así reconocieron los propios orga-nismos gubernamentales. Esta tesis incluye tres artículos publicados durante los brotes de COVID-19 y una investi-gación adicional fuera del conjunto de publicaciones. La investigación tiene como objetivo general proporcionar información a través de estimaciones alternativas. Para ello se han utilizado varias metodologías, entre ellas los modelos matemáticos de predicción epidemio-lógica, el Mejor Ajuste de Valores Relacionados (BARV), los análisis de diferentes encues-tas y la metodología bibliométrica, aprovechando u ofreciendo alternativas a los métodos bayesianos más complejos, las simulaciones de Monte Carlo o las cadenas de Markov, aun-que algunos datos obtenidos se apoyan parcialmente en estas metodologías. Cada artículo aborda un tema esencial relacionado con la pandemia COVID-19. La primera publicación se centra en los datos epidemiológicos básicos. Se refiere al primer brote de COVID-19, estimando su duración, incidencia, prevalencia, tasa de fallecimientos sobre infectados (IFR) y tasa de fallecimientos sobre casos (confirmados) (CFR). Como dato destacado de este trabajo, se previó que la seroprevalencia era demasiado baja para que la inmunidad de rebaño desempeñara algún papel. Aunque el valor obtenido fue aproxima-damente un 2% inferior al que demostró posteriormente un estudio poblacional (Instituto Carlos III), la conclusión sobre la inmunidad de rebaño no cambió, y los resultados confir-maron la idoneidad del enfoque. La segunda publicación se centró en las cuestiones legales y las noticias falsas, analizando la reticencia de la población a vacunarse, el impacto de las falsas noticas en estos comporta-mientos, las posibilidades legales de hacer obligatoria la vacuna y las posibles acciones contra los profesionales de la salud que publican noticias falsas. La principal conclusión fue que, aunque se podría encontrar una vía legal para la obligatoriedad de la vacunación, y para la persecución gubernamental de las noticias falsas, la opinión ciudadana parece prefe-rir que la administración no tome la iniciativa, por lo que se recomienda promover y fomen-tar la concienciación ciudadana. La tercera publicación presentó un modelo matemático simplificado para la estimación del coste-efectividad de la vacuna contra la COVID-19. Se actualizan los datos de dos fechas para la estimación de los costes directos para el sistema sanitario debidos a la COVID-19, computando el coste por ciudadano y por Producto Interior Bruto (PIB), así como el coste-efectividad de la vacuna. La estimó razón de coste-efectividad incremental (RCEI) para dos dosis por persona a un coste de 30 euros cada dosis (incluida la administración). Asumien-do al 70% de efectividad y con el 70% de la población vacunada resultó ser de 5.132 euros (4.926 - 5.276) por año de vida ajustado a calidad (AVAC) ganado (a 17 de febrero de 2021). Una cifra que desciende cada día de pandemia activa. Se incluyó una investigación adicional, no incorporada en el conjunto de artículos, centrada en los recursos humanos y la educación. Se analizaron los temas preocupan al personal de primera línea, es decir, a la enfermería, y cómo la pandemia ha afectado a sus publicaciones científicas, como índice de los cambios en el clima laboral que sufre este colectivo. Median-te un estudio bibliométrico comparativo entre las publicaciones de 2019 y 2020, se analizó el cambio de temas y ámbitos como reflejo del impacto del COVID-19 en el personal de enfermería. Así se comprobó que, en los ámbitos de enfermería de atención especializada, y sobre todo e / [CA] El brot de Coronavirus SARS-CoV-2 va representar un repte per a l'economia, la vida soci-al i els serveis sanitaris. Quan més es necessitava la informació per a la planificació econò-mica, malgrat esforços extraordinaris, els serveis de vigilància i notificació no van ser capa-ços d'oferir dades consistents, com així van reconèixer els mateixos organismes governa-mentals. Aquesta tesi inclou tres articles publicats durant els brots de COVID-19 i una investigació addicional fora del conjunt de publicacions. La investigació té com a objectiu general pro-porcionar informació a través d'estimacions alternatives. Per a això s'han utilitzat diverses metodologies, entre elles els models matemàtics de predicció epidemiològica, el Millor Ajust de Valors Relacionats (BARV), les anàlisis de diferents enquestes i la metodologia bibliomètrica, aprofitant o oferint opcions alternatives als mètodes bayesians més comple-xos, les simulacions de Montecarlo o les cadenes de Markov, tot i que algunes dades obtin-gudes es recolzen parcialment en aquestes metodologies. Cada article aborda un tema essen-cial relacionat amb la pandèmia COVID-19. La primera publicació se centra en les dades epidemiològiques bàsiques. Es refereix al pri-mer brot de COVID-19, calculant la seua durada, incidència, prevalença, taxa de defuncions sobre infectats (IFR) i taxa de defuncions sobre casos (confirmats) (CFR). Com a dada des-tacada d'aquest treball, es va preveure que la seroprevalença era massa baixa perquè la im-munitat de ramat exercirà algun paper. Tot i que el valor obtingut va ser aproximadament un 2% inferior al demostrat posteriorment en un estudi poblacional (Institut Carles III), la conclusió sobre la immunitat de ramat no va canviar, i els resultats van confirmar la idoneï-tat de l'enfocament. La segona publicació es va centrar en les qüestions legals i les notícies falses, analitzant la reticència de la població a vacunar-se, l'impacte de les falses notícies en aquests comporta-ments, les possibilitats legals de fer obligatòria la vacuna i les possibles accions contra els professionals de la salut que publiquen notícies falses. La principal conclusió va ser que, tot i que es podria trobar una via legal per l'obligatorietat de la vacunació, i per la persecució governamental de les notícies falses, l'opinió ciutadana sembla preferir que l'administració no prenga la iniciativa, per la qual cosa es recomana promoure i fomentar la conscienciació ciutadana. La tercera publicació va presentar un model matemàtic simplificat per a l'estimació del cost-efectivitat de la vacuna contra la COVID-19. S'actualitzen les dades de dues dates per a l'estimació dels costos directes per al sistema sanitari deguts a la COVID-19, computant el cost per ciutadà i per Producte Interior Brut (PIB), així com el cost-efectivitat de la vacuna. La va estimar raó de cost-efectivitat incremental (RCEI) per dues dosis per persona a un cost de 30 euros cada dosi (inclosa l'administració). Assumint al 70% d'efectivitat i amb el 70% de la població vacunada va resultar ser de 5.132 euros (4.926 - 5.276) per any de vida ajustat a qualitat (AVAQ) (a 17 de febrer de 2021). Una xifra que descendeix cada dia de pandèmia activa. Es va afegir una investigació addicional, no inclosa en el conjunt d'articles, centrada en els recursos humans i l'educació. Es van analitzar els temes que preocupen al personal de pri-mera línia, és a dir, a la infermeria, i com la pandèmia ha afectat les seues publicacions cien-tífiques, com a índex dels canvis en el clima laboral que pateix aquest col·lectiu. Mitjançant un estudi bibliomètric comparatiu entre les publicacions de 2019 i 2020, es va analitzar el canvi de temes i camps com a reflex de l'impacte del COVID-19 en el personal d'infermeria. Així es va comprovar que en els àmbits d'infermeria d'atenció especialitzada, i sobretot en atenció primària, els principals problemes detectat / [EN] The SARS-CoV-2 Coronavirus outbreak has posed a challenge to the economy, social life, and health services. Just when information was most needed for economic planning, moni-toring, and reporting services were unable, despite extraordinary efforts to provide con-sistent data, as government agencies themselves acknowledged. This thesis includes three articles published during the COVID-19 outbreaks and additional research outside the publication set. The overall aim of the research is to provide infor-mation through alternative estimates. Several methodologies have been used, including mathematical models for epidemiological prediction, Best Adjustment of Related Values (BARV), analyses of different surveys and bibliometric methodology, taking advantage of or offering an alternative to, more complex options such as Bayesian methods, Monte Carlo simulations or Markov chains, although some data obtained are partially supported by these methodologies. Each article addresses a key issue related to the COVID-19 pandemic. The first publication focuses on basic epidemiological data. It refers to the first outbreak of COVID-19, estimating its duration, incidence, prevalence, Infection Fatality Rate (IFR) and Case Fatality Rate (CFR). As a highlight of this work, the seroprevalence was anticipated to be too low for herd immunity to play a role. Although the value obtained was approximate-ly 2% lower than that subsequently demonstrated by a population-based study (Instituto Carlos III), the conclusion on herd immunity remained unchanged, and the results con-firmed the appropriateness of the approach. The second publication focuses on legal issues and fake news, analysing reluctance to be vaccinated in the population, the impact of fake news on these behaviours, the legal possi-bilities of making vaccination mandatory, and possible actions against health professionals who publish fake news. The main conclusion was that, although a legal avenue could be found for mandatory vaccination and for governmental prosecution of fake news, public opinion seems to prefer that the authorities do not take the initiative, therefore it recom-mends promoting and encouraging public awareness. The third publication presented a simplified mathematical model for estimating the cost-effectiveness of the COVID-19 vaccine. Data from two dates were obtained for the estimation of the direct costs to the health system due to COVID-19, computing the cost per citizen and per Gross Domestic Product (GDP), as well as the cost-effectiveness of the vaccine. The estimated incremental cost-effectiveness ratio (ICER) was calculated for two doses per person at a cost of 30 euros per dose (including administration). Assuming 70% effectiveness and with 70% of the population vaccinated, it was found to be 5,132 euros (4,926 - 5,276) per quality-adjusted life year (QALY) gained (as of 17 February 2021). The figure decreases with each day of the active pandemic. Additional research not included in the set of articles focuses on human resources and education. It analyses the concerns of frontline staff, i.e., nurses, and how the pandemic has affected their scientific publications, as an index of the changes in the work climate experienced by this group. Through a comparative bibliometric study of publications in 2019 and 2020, the change in topics and fields was analysed, as a reflection of the impact of COVID-19 on nursing staff. It was found that in the fields of specialised care nursing and above all in primary care, the main problems detected are those related to protective measures and psychological factors, while the publications of nursing staff in nursing homes showed an increase in topics related to management and organisation. Finally, some aspects of the implementation of telecommuting and distance learning have been reviewed. Some of the boosts in this field resulting from the pandemic could be very useful and remain in the future, such as the incorporation of telewo / Marco Franco, JE. (2021). What have we learned from the economic impact of the Covid-19 outbreak? Critical analysis of economic factors and recommendations for the future [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/174883 / Compendio

INTRODUÇÃO: A hanseníase é uma doença infecciosa crônica granulomatosa, cujo agente etiológico é uma bactéria de vida intracelular obrigatória, o Mycobacterium leprae, que tem no homem seu principal reservatório. A doença possui distribuição universal, predominando atualmente, em latitudes tropicais e tem sido enquadrada entre as enfermidades negligenciadas, atingindo desproporcionalmente populações pobres e marginalizadas. O bacilo é altamente contagioso, de baixa patogenicidade e acomete primordialmente pele e nervos, com grande potencial incapacitante. A doença grassou no Velho Mundo durante a Idade Média e praticamente desapareceu da Europa ainda no início do século XX, antes que qualquer recurso terapêutico eficaz estivesse disponível. Introduzida com os primeiros colonizadores europeus, a hanseníase é doença endêmica no Brasil e um problema de saúde pública. A hanseníase é hiperendêmica em muitos municípios, notadamente nos estados das regiões Norte e Centro-Oeste, que abrangem biomas de cerrado, pântano e floresta amazônica, em vastas áreas de baixa densidade demográfica; estas áreas vêm sofrendo enorme pressão antrópica relacionada ao incremento de atividades agropecuárias e extrativistas, gerando preocupações em relação ao impacto ambiental sobre a saúde humana, decorrente de transformações na dinâmica territorial. OBJETIVO: O propósito desta pesquisa foi conhecer o efeito ecológico de fatores sociodemográficos na delimitação de espaços endêmicos de hanseníase e gerar hipóteses sobre a relação entre a constituição do território e a exposição ambiental ao agente biológico da doença. MATERIAL E MÉTODOS: Supondo que a variação dos fatores de risco para contrair hanseníase pudesse ser maior entre grupos populacionais do que entre indivíduos, foi empreendido um estudo epidemiológico de delineamento ecológico do tipo grupo múltiplo, envolvendo 203 municípios dos estados do Mato Grosso e Mato Grosso do Sul, que estão localizados na região Centro-Oeste do Brasil. Foram constituídas variáveis sociodemográficas de exposição e a variável de efeito foi representada pela taxa de detecção média anual de hanseníase entre os anos de 2000 e 2006. Foram aproveitados dados secundários provenientes do Instituto Brasileiro de Geografia e Estatística e do Ministério da Saúde. Para compor um modelo multivariado, 14 variáveis foram analisadas por regressão linear simples e selecionadas sete variáveis com probabilidade de p < 0,2 para o coeficiente de inclinação da reta de regressão. As variáveis independentes selecionadas foram passo a passo testadas, simultaneamente e analisada a associação da variável dependente, visando o ajuste de um modelo singular da variabilidade da taxa de detecção de hanseníase. RESULTADOS: As variáveis que restaram no modelo após o processo de ajuste foram: Proporção da população moradora em domicílios com seis ou mais pessoas; Proporção da população não natural do estado; e, Cobertura populacional da estratégia de Atenção Saúde da Família. Estas variáveis juntas explicam 24,1% da variação nas taxas de detecção de hanseníase. CONCLUSÕES: Fatores sociodemográficos representam um importante domínio na epidemiologia da doença. A associação positiva do desfecho com a cobertura da estratégia de Atenção Saúde da Família indica que deve haver melhora no acesso ao diagnóstico mediante a implantação de modelos de Atenção Primária à Saúde baseados em racionalidades preventivas. Doentes poderiam ter sua contagiosidade interrompida mais precocemente, uma vez melhorada a capacidade diagnóstica dos serviços de saúde. Como recomendação para melhorar o acesso ao diagnóstico nas áreas endêmicas, a adoção da estratégia de Atenção Saúde da Família deve ser encorajada. Aglomeração domiciliar como variável ecológica foi interpretada como sendo um indicador socioeconômico indireto, mais do que propriamente relacionada às condições de contato. A qualidade da moradia, talvez seja mais importante para controle da endemia, tanto quanto possa vir acompanhada de melhorias gerais no padrão de vida. Reservatórios do M. leprae constituídos por indivíduos que eliminam bacilos cronicamente são os que perpetuam a endemia, embora possam, em tese, serem suplementados por fontes secundárias representadas por portadores transitórios. Fatores ligados à formação da fronteira agrícola e à urbanização brasileira podem ter fomentado a endemia de hanseníase, ao predisporem a renovação de susceptíveis pelas migrações, que modificam a composição populacional quanto à experiência de contato com o bacilo. Migrações poderiam romper os focos de hanseníase que estivessem saturados de indivíduos resistentes ao redistribuir espacialmente a população susceptível, levar infectantes para áreas indenes ou instalar as premissas biológicas e territoriais para tornar o contágio recorrente na população, mesmo que o contingente demográfico proveniente de imigrações não seja predominantemente mais vulnerável à doença. Tecnicização rural e constrições na esfera do trabalho têm movimentado populações que procuram refúgio nas periferias das cidades, caracterizadas por escassa infraestrutura urbana e rápido crescimento demográfico, supostamente continentes de grupos humanos dotados de diferentes perfis de resistência ao M. leprae. O circuito inferior da economia, uma resposta social à escassez de meios de vida e um traço da territorialização brasileira, tem oferecido os predicados espaciais para a persistência da endemia de hanseníase nos bolsões de pobreza urbana, ao gerar uma multiplicidade de contatos em proximidade e alimentar suas relações sociais de uma massa de recém-chegados do campo e da cidade, sua principal e mais abundante variável. Se a geografia estuda as condições de vida sobre a terra, estes resultados sugerem que a topografia médica, para além da descrição dos aspectos demográficos e socioeconômicos dos lugares de surgimento de doenças, pode contribuir em muito ao conhecimento em saúde, ao considerar analisar tais fatores enquanto potenciais condicionantes de endemias / BACKGROUND: Leprosy is a chronic granulomatous infectious disease whose causative agent is an obligate intracellular bacterium of life, Mycobacterium leprae, which has its main reservoir in man. The disease has a worldwide distribution, currently prevailing in tropical latitudes and has been framed between neglected diseases, disproportionately affecting poor and marginalized populations. The bacillus is highly contagious, and low pathogenic primarily affects the skin and nerves, with great potential crippling. The disease raged in the Old World during the Middle Ages and still practically disappeared from Europe in the early twentieth century, before any effective therapeutic resource was available. Introduced with the first European settlers, leprosy is endemic in Brazil and a public health problem. Leprosy is hyperendemic in many cities, especially in the states of North and Midwest, covering biomes savannah, swamp and rainforest, in vast areas of low population density; these areas have suffered huge human pressure related to increased activity agricultural and extractive, generating concerns about the environmental impact on human health, due to dynamic changes in territorial. OBJECTIVE: The purpose of this research was to understand the ecological effect of sociodemographic factors in the delimitation of leprosy-endemic areas and generating concerns about the relationship between the constitution of the territory and environmental exposure to the biological agent of the disease. MATERIAL AND METHODS: Assuming that the variation of the risk factors for contracting leprosy could be higher among population groups than between individuals, an epidemiological study was undertaken to design ecological type group multiple, involving 203 municipalities in the states of Mato Grosso and Mato Grosso do Sul, which are located in the Midwest region of Brazil. Sociodemographic variables were recorded for exposure and effect was variable represented by annual average detection rate of leprosy between 2000 and 2006. We utilized secondary data from the Brazilian Institute of Geography and Statistics and the Ministry of Health to compose a multivariate model, 14 variables were analyzed by linear regression and seven variables selected with probability p<0.2 for the slope coefficient of regression line. The independent variables were tested step by step, and simultaneously analyzed the association of the dependent variable in order to fit a model of the variability of the detection rate of leprosy. The variables that remained in the model after adjustment process were: \"Proportion of population living in households with six or more people,\" \"Proportion of population unnatural state,\" and \"Coverage of Population Health Care Strategy Family \". These variables together explain 24.1% of the variation in detection rates of leprosy. CONCLUSIONS: Sociodemographic factors represent an important area in the epidemiology of the disease. The positive association with the outcome of the strategic coverage of Family Health Care indicates that there must be improved access to diagnosis by implementing models of primary care-based preventive rationales. Patients could have their contagiousness interrupted earlier, once improved the diagnostic capacity of health services. As a recommendation to improve access to diagnosis in endemic areas, the adoption of the strategy of the Family Health Care should be encouraged. Household crowding as ecological variable was interpreted as an indirect socioeconomic indicator, rather than strictly related to contact conditions. The quality of housing, perhaps most important for disease control, as far as can be accompanied by general improvements in living standards. Reservoirs of M. leprae consist of individuals who are chronically eliminate bacilli that perpetuate endemic, although, in theory, be supplemented by secondary sources represented by transient carriers. Factors related to the formation of the agricultural frontier and the Brazilian urbanization may have fostered endemic leprosy, predispose to the renewal of the likely migration, which modify the composition of the population as to the experience of contact with the bacillus. Migration could break outbreaks of leprosy that were saturated with individuals resistant to spatially redistribute the population likely lead to infective areas unaffected or install the territorial and biological assumptions to make the recurring infection in the population, even though the population from immigration quota is not predominantly more vulnerable to disease. Technicisation rural and constrictions in the sphere of labor are busy people seeking refuge on the outskirts of cities, characterized by poor urban infrastructure and rapid population growth, supposedly continents groups of humans with different resistance profiles to M. leprae. The lower circuit of the economy, a social response to the scarcity of livelihood and a dash of Brazilian territorialization, has offered the spatial predicates for the persistence of endemic leprosy in pockets of urban poverty, to generate a plurality of contacts in proximity and feed their social relationships from a mass of newcomers from the countryside and the city, its main and most abundant variable. If geography studies the conditions of life on earth, these results suggest that medical topography, beyond the description of the demographic and socioeconomic aspects of the places outbreaks of diseases, can contribute greatly to health knowledge, to consider examining such factors as potential determinants of diseases