Utilização de modelos de regressão aplicados a dados com inflacionamento de zeros: Estudo da ocorrência de carrapatos em municípios no interior do estado do Rio de Janeiro / Use of regression models applied to data with inflation of zeros: Study of the occurrence of ticks in municipalities inside the state of Rio de Janeiro

Os mais utilizados entre os Modelos Lineares Generalizados (GLM) são as regressões logística e de Poisson. Apesar disso, nos últimos anos, modelos capazes de suportar superdispersão e inflacionamento de zeros surgiram: modelos para alteração de zeros e inflacionamento de zeros. O desafio é aplicar tais metodologias em um problema de saúde pública, carrapatos Amblyomma cajennense em áreas de transição rural-urbana. O objetivo deste artigo é estudar os fatores climáticos associados à ocorrência de carrapatos A. cajennense adultos em Seropédica e Mangaratiba/RJ, através do ajuste de modelos de regressão. Foram realizadas coletas de carrapatos entre dezembro/2008 e setembro/2011. A variável resposta foi contagem de carrapatos; as 48 variáveis independentes estavam relacionadas à temperatura média (ºC), umidade relativa do ar (%) e precipitação (mm). Estatística descritiva e análises bivariadas e multivariadas foram realizadas utilizando-se cinco tipos de GLM: regressão de Poisson, binomial negativa, extra-Poisson (variância = ?; variância = ?2) e ZIP (Poisson com inflacionamento de zeros). Nove variáveis independentes foram significativas em pelo menos dois modelos bivariados. Os modelos multivariados mostraram que os melhores parâmetros foram apresentados pelos modelos ZIP, seguidos da regressão de Poisson. Esses resultados corroboram o fato de que ZIP são os GLM mais adequados para suportar análises com inflacionamento de zeros. É possível concluir através deste estudo que ZIP é o GLM mais adequado para analisar dados de contagem de A. cajennense adultos associados a variáveis climáticas nas regiões estudadas. Conclui-se, ainda, que a regressão de Poisson também pode proceder a uma análise de alto padrão para dados de contagem com inflacionamento de zeros

Spatial Econometrics Applied to Study the Influencing Factors of Honey Prices in Brazil

Recently, empirical econometric research has started to take into account the potential bias and loss of efficiency when spatial effects are ignored in the estimation process. The spatial econometrics methods deals with this kind of problem, by incorporating the spatial dependence into model specification. The application of this methodology has wide use, including rural economy, as apiculture. Currently, brazilian beekeeping is undergoing an expressive growth, projecting the country through the honey production and other bee products as well. Although, beekeeping sector has faced some important problems to reduce the deficits that strongly influence the beekeeping chain. Important issues are related to market, especially to understand the factors that influence the honey prices. This study aims to identify socio-economic, technological, management and geographic factors that have influenced the honey prices in Brazil. The analyses were based on classical linear and spatial econometrics regression models. In order to measure spatial dependence the Moran’s Index was applied and the stepAIC and Nagelkerke Pseudo-R² approaches to select the most appropriate model. The best model identified factors linked to improper agricultural practices, access to fund, honey production level, market competition and educational level as target variables that influence the honey prices in Brazil

Leishmaniose visceral: uma proposta para a mensuração da percepção dos profissionais de saúde em Uruguaiana (Rio Grande do Sul)

Introduction: Visceral leishmaniasis (VL) is  considered one of the most relevant zoonoses in the Americas due to its high magnitude, wide geographic distribution, and high fatality rate. Objective: Evaluate the perception of health professionals regarding the occurrence of VL in Uruguaiana (RS). Method: A cross-sectional observational study was carried out using a self-administered questionnaire from December 2016 to January 2017. Results: One hundred eighty-three health professionals participated in the study (one hundred thirty-six members of the Family Health Strategy, twenty endemic control agents and twenty-seven veterinarians). Health professionals’ perception deficiencies were identified regarding the epidemiology and symptomatology of the disease. Conclusions: This study showed weaknesses in the knowledge of health professionals about the epidemiology and symptoms of VL, which may impact the early detection of cases and,  consequently, their favorable resolution. It is necessary to invest in training strategies on VL, aiming to correct gaps in knowledge and foster discussion on the subject.Introdução: A leishmaniose visceral (LV) é  considerada uma das zoonoses mais relevantes das Américas devido à acentuada magnitude, à ampla distribuição geográfica e à alta taxa de letalidade. Objetivo: Avaliar a percepção dos profissionais de saúde quanto à ocorrência da LV em Uruguaiana (Rio Grande do Sul). Método: Estudo observacional transversal empregando um questionário autoaplicável durante o período de dezembro de 2016 a janeiro de 2017. Resultados: Participaram 183 profissionais de saúde, sendo 136 integrantes da Estratégia Saúde da Família, 20 agentes de controle de endemias e 27 veterinários. Identificaram-se deficiências de percepção dos profissionais de saúde a respeito da epidemiologia e da sintomatologia da doença. Conclusões: Fragilidades na percepção dos profissionais de saúde quanto à epidemiologia e à sintomatologia da LV ficaram evidenciadas, o que poderá impactar na detecção precoce de casos da doença e, consequentemente, na execução das ações preconizadas para o controle e prevenção dadoença. É necessário investir em estratégias de capacitação sobre a LV, visando corrigir lacunas no conhecimento e fomentar discussões que englobem a complexidade do tema

Space, time and longitudinal modeling: different approaches for the urban leptospirosis study

Made available in DSpace on 2011-05-04T12:42:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2009Fundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sergio Arouca. Rio de Janeiro, RJ, Brasil.(...) O objetivo desta tese foi modelar os fatores de risco associados à ocorrência de leptospirose urbana em diferentes contextos, com especial atenção para aspectos espaciais e temporais. Foram utilizadas técnicas de modelagem tais como, modelos generalizados aditivos e mistos. Também explorou-se técnicas de detecção de aglomerados espaço-temporais. (...)Leptospirosis, a disease caused by pathogenic spirochete of the genus Leptospira, is one of the most widespread zoonoses in the world, considered a major public health problem associated with the lack of sanitation and poverty. It is endemic in Brazil, data from surveillance show that outbreaks of leptospirosis occur as cyclical annual epidemics during rainfalls. The aim of this thesis was modeling the risk factors associated with the occurrence of leptospirosis in di erent urban contexts, with particular attention to spatial and temporal aspects. We used some modeling techniques such as generalized additive and mixed models. Techniques for detection space-time clusters were also explored. This thesis has prioritized the use of free softwares - R, ubuntu linux operating system, LATEX , SatScan (this is not open source but free). This thesis was prepared in the form of three articles. In the rst article is presented a spatio-temporal analysis of leptospirosis cases occurrence in Rio de Janeiro between 1997 and 2002. Using the detection of space-time clusters - \outbreaks" method - were statistically signi cant only cluster ocorred in 1997 and 1998. Generalized Linear Mixed Models were used to evaluate the risk factors associated with the occurrence of cases that belonged to outbreaks in endemic cases. The cases belonging to the outbreaks are associated with the occurrence of rainfall over 4 mm (OR, 3.71; 95% CI, 1.83 - 7.51). There were no signi cant associations with socioeconomic covariates, in other words, being endemic or epidemic leptospirosis occurs in the same population. The second and third articles examined a seroprevalence survey and seroconversion cohort conducted in Pau da Lima community, Salvador, Bahia. In both Generalized Additive Models were used to t the exposure variables both in individuals and peridomicile context, as well as to estimate the spatial area of leptospirosis risk. The signi cant variables were: gender, age, presence of rats in the peridomicile, domicile near a trash collectin or an open sewer and domicile altitude above sea level. Studies show that individual and contextual variables explain much of the spatial variability of leptospirosis, but there are still factors that were not measured in the studies but which should be investigated. The maps of risk of seroprevalence and seroconversion show distinct regions where the spatial e ect is signi cantly di erent from the global average. It is still lack for a more robust integration between the professionals who develop and operate the GIS, epidemiologists and biostatistics. This integration represents an important advance enabling the development and use of these techniques in Public Health support. The study of prevalence and incidence of endemic areas, in the leptospirosis context, it is very complex and still grow up. The reunion of professional specialists from several areas of human knowledge (eg, clinicians, epidemiologists, geographers, biologists, statisticians, engineers, etc.), it is essential to advance the knowledge about the disease and their relationship to social inequality and environmental well to contribute to the creation of efficient and e ective measures to control endemic diseases

Geoprocessing and spatial analysis for identifying leptospirosis risk areas: a systematic review

Leptospirosis is a reemerging zoonosis caused by bacteria of the genus Leptospira sp. with global importance in the medical and veterinary fields, being responsible for about 59 thousand deaths each year in the world. The use of Geographic Information Systems (GIS) in the health sector is propitious and has been adopted by human and animal health professionals as an important tool in spatial analyses of health. The objective of this study was to conduct a systematic review on the geoprocessing and spatial analysis techniques adopted for mapping risk areas of human and animal leptospirosis. The articles were collected on scientific platforms by entering the following terms: SIG/GIS, leptospirose/leptospirosis, area de risco/risk area and distribuicao espacial/spatial distribution, and included in the study if they met the following criteria: a) publication in the period from 1998 to 2017; b) identification of risk areas and/or spatial distribution of leptospirosis as one of the research topics; and c) application of GIS in the methodology. As a result, we found 40 articles, published by 15 different countries, which adopted GIS for the spatial analysis and identification of risk areas of leptospirosis. Among these, only 45% (18) conducted an spatial statistical analysis. Brazil and USA had the highest numbers of publications, 16 and 7 articles, respectively. From 2007, the use of GIS and spatial analysis techniques, applied to the theme of this study, have been intensified and diversified, and 93% of the articles elected for this review were published from 2007 to 2017. The results point to a progressive interest of health professionals in applying these techniques for monitoring and conducting epidemiological analyses of leptospirosis, besides indicating a greater need for intersectoral integration between health professionals and others, in the use of spatial analysis and GIS techniques

Landscape features associated to the occurrence of Amblyomma sculptum ticks: an application of zero inflated regression models

ABSTRACT. Bernardo-Pedro T., Silveira A.K. & Tassinari W.S. Landscape features associated to the occurrence of Amblyomma sculptum ticks: an application of zero inflated regression models. [Características de paisagem associadas à ocorrência de carrapatos Amblyomma sculptum: uma aplicação dos modelos de regressão inflacionados de zeros.] Revista Brasileira de Medicina Veterinária, 38(supl. 3):39-46, 2016. Programa de Pós-Graduação em Ciências Veterinárias, Departamento de Parasitologia Animal, Universidade Federal Rural do Rio de Janeiro, BR-465, km 7, Seropédica, RJ 23890-000, Brasil. E-mail: [email protected] The aim of the present study was to analyze the association between landscape features and occurrence of A. sculptum ticks, using zero inflated regression models. A total of 503 ticks were collected during the period of the research. Most of them were captured in sites related to the following features: 20-40m altitude (93.64%), 0-2.5% declivity (57.65%), plain land (93.04%), albaqualf type of soil (52.68%), presence of capybaras (56.06%) and high occurrence favorability of A. sculptum (84.89%). Regarding the non-inflated part of the bivariate models, all variables were significant, which means all of them contribute to A. sculptum occurrence. In the final multivariate model, only geomorphology and type of soil were relevant variables to explain A. sculptum occurrence. In conclusion, landscape features – especially geomorphology and type of soil – are associated to A. sculptum abundance in the research area, what indicates that these variables should be taken into consideration when planning tick control programs

Spatial Econometrics Applied to Study the Influencing Factors of Honey Prices in Brazil

Abstract Recently, empirical econometric research has started to take into account the potential bias and loss of efficiency when spatial effects are ignored in the estimation process. The spatial econometrics methods deals with this kind of problem, by incorporating the spatial dependence into model specification. The application of this methodology has wide use, including rural economy, as apiculture. Currently, brazilian beekeeping is undergoing an expressive growth, projecting the country through the honey production and other bee products as well. Although, beekeeping sector has faced some important problems to reduce the deficits that strongly influence the beekeeping chain. Important issues are related to market, especially to understand the factors that influence the honey prices. This study aims to identify socio-economic, technological, management and geographic factors that have influenced the honey prices in Brazil. The analyses were based on classical linear and spatial econometrics regression models. In order to measure spatial dependence the Moran's Index was applied and the stepAIC and Nagelkerke Pseudo-R² approaches to select the most appropriate model. The best model identified factors linked to improper agricultural practices, access to fund, honey production level, market competition and educational level as target variables that influence the honey prices in Brazil

Estudo descritivo da série histórica de ocorrência de carrapatos em cães assistidos em duas unidades privadas de saúde animal na zona oeste da cidade do Rio de Janeiro

Apesar da relevância que carrapatos em ambientes possuem para a saúde pública poucos são os estudos direcionados para a epidemiologia desses parasitos em ambiente urbano. Não havendo análises de dados de série temporal, o que seria muito útil para os profissionais da saúde animal com relação à profilaxia e controle desses parasitos. O objetivo deste trabalho foi realizar um estudo descritivo da série histórica de ocorrência de carrapatos em cães assistidos em duas unidades privadas de saúde animal em ambiente urbano no período de janeiro de 2000 a dezembro de 2014. Para tal utilizamos o teste gráfico de Noch para verificar diferenças nas prevalências entre os anos, assim como o teste do qui-quadradro para avaliar a prevalência entre os meses e entre os anos. Foi realizada também a correlação entre prevalência e temperatura. Foram selecionados de forma sistemática 1500 prontuários médicos veterinários. Foi verificado a não uniformidade de registro de parasitismo entre os anos. As maiores prevalências foram nos anos de 2003, 2004 e 2009 com 43,00%, 31,00% e 31,00%. O mês com maior prevalência de parasitismo foi fevereiro (26,00%) e o com menor foi setembro (11,80%), não havendo diferenças significativas. Não foram observados padrões sazonais nem de tendência temporal da prevalência de ocorrência de carrapatos em cães nesta região. Não há evidências de que a temperatura influência no aumento da prevalência da ocorrência de carrapatos em cães no ambiente urbano. A inclusão do diagnóstico específico e estágio do carrapato, bem como o número de carrapatos observados no exame do animal nos prontuários de atendimento foi considerado muito importante para que estudos epidemiológicos mais detalhados envolvendo carrapato/cão possam ser realizados