A spatial case-control study on symptomatic and inapparent primary dengue infections in an endemic city in Brazil.

We conducted a spatial case-control study nested in a dengue incidence cohort to explore the role of the spatial and socioeconomic factors in the proportion of symptomatic (cases) and inapparent primary dengue virus infections (controls). Cohort participants were children and adolescents (2 to 16 years of age) at the beginning of the follow-up. Case definitions were, for symptomatic cases, fever plus a positive lab result for acute dengue (NS1, RT-PCR, ELISA IgM/IgG), and for inapparent infection a positive result for dengue IgG (ELISA) in subjects without symptoms and with a previously negative result at baseline. The covariates included sociodemographic factors, residential location, and socioeconomic context variables of the census tracts of residence of cases and controls. We used principal component analysis to reduce the contextual covariates, with the component values assigned to each one based on their residences. The data were modeled in a Bayesian context, considering the spatial dependence. The final sample consisted of 692 children, 274 cases and 418 controls, from the first year of follow-up (2014-2015). Being male, older age, higher educational level of the head of the family and having a larger number of rooms in the household were associated with a greater chance of presenting dengue symptomatic infection at the individual level. The contextual covariates were not associated with the outcome. Inapparent dengue infection has extensive epidemiological consequences. Relying solely on notifications of symptomatic dengue infections underestimates the number of cases, preserves a silent source of the disease, potentially spreading the virus to unaffected areas.

A spatial case-control study on symptomatic and inapparent primary dengue infections in an endemic city in Brazil

ABSTRACT We conducted a spatial case-control study nested in a dengue incidence cohort to explore the role of the spatial and socioeconomic factors in the proportion of symptomatic (cases) and inapparent primary dengue virus infections (controls). Cohort participants were children and adolescents (2 to 16 years of age) at the beginning of the follow-up. Case definitions were, for symptomatic cases, fever plus a positive lab result for acute dengue (NS1, RT-PCR, ELISA IgM/IgG), and for inapparent infection a positive result for dengue IgG (ELISA) in subjects without symptoms and with a previously negative result at baseline. The covariates included sociodemographic factors, residential location, and socioeconomic context variables of the census tracts of residence of cases and controls. We used principal component analysis to reduce the contextual covariates, with the component values assigned to each one based on their residences. The data were modeled in a Bayesian context, considering the spatial dependence. The final sample consisted of 692 children, 274 cases and 418 controls, from the first year of follow-up (2014-2015). Being male, older age, higher educational level of the head of the family and having a larger number of rooms in the household were associated with a greater chance of presenting dengue symptomatic infection at the individual level. The contextual covariates were not associated with the outcome. Inapparent dengue infection has extensive epidemiological consequences. Relying solely on notifications of symptomatic dengue infections underestimates the number of cases, preserves a silent source of the disease, potentially spreading the virus to unaffected areas.

Ovipositional Reproduction of the Dengue Vector for Identifying High-Risk Urban Areas.

Identification and classification of high-risk areas for the presence of Aedes aegypti is not an easy task. To develop suitable methods to identify this areas is an essential task that will increase the efficiency and effectiveness of control measures and to optimize the use of resources. The objectives of this study were to identify high- risk areas for the presence of Ae. aegypti using mosquito traps and household visits to identify breeding sites; to identify and validate aspects of the remote sensing images that could characterize these areas; to evaluate the relationship between this spatial risk classification and the occurrence of Ae. aegypti; and provide a methodology to the health and control vector services and prioritize these areas for development of control measure. Information about the geographical coordinates of these traps will enable us to apply the kriging spatial analysis tool to generate maps with the predicted numbers of Ae. aegypti. Satellite images were used to identify the characteristic features the four areas, so that other areas could also be classified using only the sensing remote images. The developed methodology enables the identification of high-risk areas for Ae. aegypti and for the occurrence of Dengue, as well as Zika fever and Chikungunya fever using only sensing remote images. These results allow health and vector control services to prioritize these areas for developing surveillance and control measures. The use of the available resources can be optimized and potentially promote a decrease in the expected incidences of these diseases, particularly Dengue.

Ovipositional Reproduction of the Dengue Vector for Identifying High-Risk Urban Areas

Identification and classification of high-risk areas for the presence of Aedes aegypti is not an easy task. To develop suitable methods to identify this areas is an essential task that will increase the efficiency and effectiveness of control measures and to optimize the use of resources. The objectives of this study were to identify high- risk areas for the presence of Ae. aegypti using mosquito traps and household visits to identify breeding sites; to identify and validate aspects of the remote sensing images that could characterize these areas; to evaluate the relationship between this spatial risk classification and the occurrence of Ae. aegypti; and provide a methodology to the health and control vector services and prioritize these areas for development of control measure. Information about the geographical coordinates of these traps will enable us to apply the kriging spatial analysis tool to generate maps with the predicted numbers of Ae. aegypti. Satellite images were used to identify the characteristic features the four areas, so that other areas could also be classified using only the sensing remote images. The developed methodology enables the identification of high-risk areas for Ae. aegypti and for the occurrence of Dengue, as well as Zika fever and Chikungunya fever using only sensing remote images. These results allow health and vector control services to prioritize these areas for developing surveillance and control measures. The use of the available resources can be optimized and potentially promote a decrease in the expected incidences of these diseases, particularly Dengue.

Bayesian model and spatial analysis of oral and oropharynx cancer mortality in Minas Gerais, Brazil.

The objective of this study was to determine of oral and oropharynx cancer mortality rate and the results were analyzed by applying the Spatial Analysis of Empirical Bayesian Model. To this end, we used the information contained in the International Classification of Diseases (ICD-10), Chapter II, Category C00 to C14 and Brazilian Mortality Information System (SIM) of Minas Gerais State. Descriptive statistics were observed and the gross rate of mortality was calculated for each municipality. Then Empirical Bayesian estimators were applied. The results showed that, in 2012, in the state of Minas Gerais, were registered 769 deaths of patients with cancer of oral and oropharynx, with 607 (78.96%) men and 162 (21.04%) women. There was a wide variation in spatial distribution of crude mortality rate and were identified agglomeration in the South, Central and North more accurately by Bayesian Estimator Global and Local Model. Through Bayesian models was possible to map the spatial clustering of deaths from oral cancer more accurately, and with the application of the method of spatial epidemiology, it was possible to obtain more accurate results and provide subsidies to reduce the number of deaths from this type of cancer.

[Experiences, benefits and challenges of the use of geoprocessing for the development of primary health careExperiências, benefícios e desafios do uso de geoprocessamento para o desenvolvimento da atenção primária à saúde]. / Experiencias, beneficios y desafíos del uso de geoprocesamiento para el desarrollo de la atención primaria de salud.

OBJECTIVE: To review the empirical consequences of the use of geoprocessing in the management of primary health care (PHC) services, in order to disseminate the benefits of this technology and analyze the challenges that must be overcome for its contribution to the development of PHC. METHODS: A systematic review of primary studies published in Spanish, English or Portuguese between 2000 and 2017 was carried out. First, a review of the academic production was carried out by continent and type of objective. In a second stage, the studies that experimented with and evaluated the use of geoprocessing in empirical form were selected. Specific and generic benefits, as well as limitations, were reviewed. RESULTS: 134 articles were identified in the first stage of selection, half of them from the Region of the Americas. Only nine studies met the criteria and were reviewed in the second stage. These studies showed that the use of geoprocessing generates benefits that go beyond the technical benefits, with limitations that can be overcome. CONCLUSIONS: Although the benefits of using geoprocessing have been widely discussed, few studies have evaluated its implementation in PHC empirically. Practical experiences, which could easily be reproduced in different communities, show that its continued use could increase the capacity to respond to the goals of PHC, as well as to the goals of sustainable development.

OBJETIVO: Revisar as consequências empíricas do uso de geoprocessamento na gestão dos serviços de atenção primária à saúde (APS), com o propósito de difundir os benefícios do uso desta tecnologia, bem como precisar os desafios que devem ser superados para sua contribuição no desenvolvimento da APS. MÉTODOS: Foi realizada uma revisão sistemática de estudos primários publicados em espanhol, inglês ou português, entre os anos 2000 e 2017. Em primeiro lugar, uma revisão geral da produção acadêmica é efetuada por continente é tipo de objetivo. Em uma segunda etapa, são selecionados os estudos que experimentaram e avaliaram o uso de geoprocessamento em forma empírica, onde são revisados benefícios concretos é genéricos, bem como as limitações. RESULTADOS: Foram identificados 134 artigos na primeira etapa de seleção, a metade deles proveniente do continente americano. Nove estudos cumpriram os requisitos da segunda etapa; no entanto, demonstraram que o uso de geoprocesamiento gera benefícios que vão além dos benefícios técnicos, com limitações factíveis de serem superadas. CONCLUSÕES: Embora os benefícios do uso de geoprocessamento tenham sido amplamente discutidos, são escassos os estudos que avaliaram sua implementação em APS em forma empírica. Experiências práticas, que poderiam ser facilmente reproduzidas em outras comunidades, demonstram que seu uso contínuo poderia aumentar a capacidade de resposta às metas de APS, bem como às próprias metas do desenvolvimento sustentável.

Aedes aegypti breeding site in an underground rainwater reservoir: a warning.

We describe the discovery of Aedes aegypti underground breeding site in the Pinheiros neighborhood of São Paulo, SP, during an entomological survey program performed in 2016. Even with intense surveillance and vector control, large numbers of mosquitoes were present in this area. A detailed investigation allowed for the detection of Ae. aegypti in an underground reservoir used for rainwater storage. After the implementation of protection screens in the accesses, the presence of the vector was no longer detected. In this study, we discuss the frequent use of this type of reservoir structure and its risk for mosquito production.

Epidemiological profile of tuberculosis in São Paulo municipality from 2006 to 2013. / Perfil epidemiológico da tuberculose no município de São Paulo de 2006 a 2013.

BACKGROUND: Tuberculosis is a serious public health problem that still persists in the world and in Brazil. The municipality of São Paulo, Brazil, is among the prioritized ones in the country for disease control. OBJECTIVE: To describe the epidemiological profile of all new tuberculosis cases in São Paulo municipality reported between the years 2006 and 2013. METHODS: The variables selected for the study were: socioeconomic, demographic and clinical-epidemiologic obtained through the online information system TB-WEB. A descriptive analysis of the data was performed to undertake the comparison among the years. To study the historical series, linear trend analysis was held. RESULTS AND DISCUSSION: There was an increase in the tuberculosis incidence rate in children under 15 years and in homeless people. The cure rate has improved as the proportion of completion of supervised treatment and the proportion of cases diagnosed by primary care clinics. The disease is unevenly distributed within the municipality of São Paulo and there are districts that were not able to improve the tuberculosis control. CONCLUSION: The municipal tuberculosis program control needs to target the vulnerable groups and the regions of the city where the incidence rates are higher.

INTRODUÇÃO: A tuberculose é um grave problema de saúde que ainda persiste no mundo e no Brasil. O município de São Paulo é considerado prioritário para o controle da doença. OBJETIVO: Descrever o perfil epidemiológico de todos os casos novos de tuberculose no município de São Paulo notificados entre os anos de 2006 e 2013. MÉTODOS: As variáveis selecionadas para o estudo foram as socioeconômicas, demográficas e as clínico-epidemiológicas obtidas através do sistema de informação online TB-WEB. Foi realizada uma análise descritiva dos dados e feita a comparação entre os anos. Para estudo da série histórica realizou-se análise de tendência linear. Um mapa temático foi confeccionado para visualizar a distribuição da doença no espaço urbano da cidade. RESULTADOS E DISCUSSÃO: Houve um aumento da taxa de incidência-ano da tuberculose em menores de 15 anos e em moradores de rua. A taxa de cura melhorou, bem como a proporção de realização do tratamento supervisionado e a proporção dos diagnósticos feitos pela Atenção Básica. A doença está desigualmente distribuída no espaço do município, sendo que há distritos administrativos que não estão conseguindo progredir com relação ao seu controle. CONCLUSÃO: O programa municipal de controle da tuberculose necessita envidar esforços para os grupos vulneráveis para a tuberculose identificados e para as regiões da cidade com maior taxa de incidência-ano da doença.

Spatial risk of tuberculosis mortality and social vulnerability in Northeast Brazil.

INTRODUCTION: Tuberculosis (TB) is the most common infectious disease in the world. We aimed to analyze the spatial risk of tuberculosis mortality and to verify associations in high-risk areas with social vulnerability. METHODS: This was an ecological study. The scan statistic was used to detect areas at risk, and the Bivariate Moran Index was used to verify relationships between variables. RESULTS: High-risk areas of tuberculosis mortality were statistically significantly associated with domain 2 of the Social Vulnerability Index (I=0.010; p=0.001). CONCLUSIONS: This study provides evidence regarding areas with high risk and that vulnerability is a determinant of TB mortality.

Visceral leishmaniasis in the state of Sao Paulo, Brazil: spatial and space-time analysis.

OBJECTIVE: To perform both space and space-time evaluations of visceral leishmaniasis in humans in the state of Sao Paulo, Brazil. METHODS: The population considered in the study comprised autochthonous cases of visceral leishmaniasis and deaths resulting from it in Sao Paulo, between 1999 and 2013. The analysis considered the western region of the state as its studied area. Thematic maps were created to show visceral leishmaniasis dissemination in humans in the municipality. Spatial analysis tools Kernel and Kernel ratio were used to respectively obtain the distribution of cases and deaths and the distribution of incidence and mortality. Scan statistics were used in order to identify spatial and space-time clusters of cases and deaths. RESULTS: The visceral leishmaniasis cases in humans, during the studied period, were observed to occur in the western portion of Sao Paulo, and their territorial extension mainly followed the eastbound course of the Marechal Rondon highway. The incidences were characterized as two sequences of concentric ellipses of decreasing intensities. The first and more intense one was found to have its epicenter in the municipality of Castilho (where the Marechal Rondon highway crosses the border of the state of Mato Grosso do Sul) and the second one in Bauru. Mortality was found to have a similar behavior to incidence. The spatial and space-time clusters of cases were observed to coincide with the two areas of highest incidence. Both the space-time clusters identified, even without coinciding in time, were started three years after the human cases were detected and had the same duration, that is, six years. CONCLUSIONS: The expansion of visceral leishmaniasis in Sao Paulo has been taking place in an eastbound direction, focusing on the role of highways, especially Marechal Rondon, in this process. The space-time analysis detected the disease occurred in cycles, in different spaces and time periods. These meetings, if considered, may contribute to the adoption of actions that aim to prevent the disease from spreading throughout the whole territory of São Paulo or to at least reducing its expansion speed. OBJETIVO: Avaliar, no espaço e espaço-tempo, a ocorrência da leishmaniose visceral em humanos no estado de São Paulo, Brasil. MÉTODOS: Considerou-se como população de estudo os casos autóctones e óbitos por leishmaniose visceral em humanos ocorridos em São Paulo entre 1999 e 2013 e, como área de estudo, a região oeste do estado. Construíram-se mapas temáticos que mostraram a disseminação da leishmaniose visceral em humanos nos municípios. Ferramentas de análise espacial Kernel e razão Kernel foram utilizadas para obter, respectivamente, a distribuição dos casos e óbitos e a distribuição da incidência e mortalidade. Utilizaram-se estatísticas de varredura para identificar aglomerados espaciais e espaço-temporais de casos e óbitos. RESULTADOS: Os casos de leishmaniose visceral em humanos, no período de estudo, ocorreram na parte ocidental de São Paulo e sua expansão territorial seguiu principalmente o curso da rodovia Marechal Rondon, no sentido oeste-leste. As incidências foram caracterizadas como duas sequências de elipses concêntricas com intensidade decrescente. A primeira, com maior intensidade, teve epicentro no município de Castilho (cruzamento da rodovia Marechal Rondon com a divisa com o estado de Mato Grosso do Sul) e a segunda, em Bauru. A mortalidade apresentou comportamento similar ao da incidência. Os aglomerados espaciais e espaço-temporais de casos coincidiram com as duas áreas de maiores incidências. Ambos os aglomerados espaço-temporais identificados, mesmo sem coincidirem temporalmente, tiveram início após três anos da detecção dos casos humanos e tiveram a mesma duração, seis anos. CONCLUSÕES: A expansão da leishmaniose visceral em São Paulo vem ocorrendo no sentido oeste-leste, com destaque ao papel das rodovias, especialmente a Marechal Rondon, neste processo. A análise espaço-temporal detectou, em diferentes espaços e períodos de tempo, ciclicidade na ocorrência da doença. Esses encontros, se considerados, podem colaborar para a adoção de ações que visem a evitar que a doença se espalhe por todo o território paulista ou, no mínimo, diminuir sua velocidade de expansão.