Automatic mapping of high-risk urban areas for Aedes aegypti infestation based on building facade image analysis.

BACKGROUND: Dengue, Zika, and chikungunya, whose viruses are transmitted mainly by Aedes aegypti, significantly impact human health worldwide. Despite the recent development of promising vaccines against the dengue virus, controlling these arbovirus diseases still depends on mosquito surveillance and control. Nonetheless, several studies have shown that these measures are not sufficiently effective or ineffective. Identifying higher-risk areas in a municipality and directing control efforts towards them could improve it. One tool for this is the premise condition index (PCI); however, its measure requires visiting all buildings. We propose a novel approach capable of predicting the PCI based on facade street-level images, which we call PCINet. METHODOLOGY: Our study was conducted in Campinas, a one million-inhabitant city in São Paulo, Brazil. We surveyed 200 blocks, visited their buildings, and measured the three traditional PCI components (building and backyard conditions and shading), the facade conditions (taking pictures of them), and other characteristics. We trained a deep neural network with the pictures taken, creating a computational model that can predict buildings' conditions based on the view of their facades. We evaluated PCINet in a scenario emulating a real large-scale situation, where the model could be deployed to automatically monitor four regions of Campinas to identify risk areas. PRINCIPAL FINDINGS: PCINet produced reasonable results in differentiating the facade condition into three levels, and it is a scalable strategy to triage large areas. The entire process can be automated through data collection from facade data sources and inferences through PCINet. The facade conditions correlated highly with the building and backyard conditions and reasonably well with shading and backyard conditions. The use of street-level images and PCINet could help to optimize Ae. aegypti surveillance and control, reducing the number of in-person visits necessary to identify buildings, blocks, and neighborhoods at higher risk from mosquito and arbovirus diseases.

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.

Use of an Extended Premise Condition Index for detection of priority areas for vector control actions.

The Premise Condition Index (PCI), proposed by Tun-Lin and colleagues in 1995, is a score that considers the conditions of a premise as well its yards and degree of shading. They hypothesized that the higher its value the greater the probability of the premise having the presence of Aedes aegypti. This study aimed to evaluate if there is a correspondence between PCI and Ae. aegypti infestation in four areas of a large city in the State of São Paulo, Brazil, if the inclusion of new categories related to the presence of animals in premises would increase the probability of detecting predictive areas for vector control actions and, if so, to propose an expanded PCI. The positivity of the premises for the presence of Ae. aegypti was modeled considering a Bernoulli probability distribution, in a Bayesian context using the Integrated Nested Laplace Approximation. The study showed that, in general, the higher the value of the PCI of a premise, the more likely it is to have the presence of Ae. aegypti, and the inclusion of information on the animals' presence can increase the discriminatory power of PCI. These results support the proposition of an extended PCI that would consider, in addition to the conditions of the premise, the presence of animals to classify it regarding the risk of the presence of Ae. aegypti.

Use of an Extended Premise Condition Index for detection of priority areas for vector control actions

The Premise Condition Index (PCI), proposed by Tun-Lin and colleagues in 1995, is a score that considers the conditions of a premise as well its yards and degree of shading. They hypothesized that the higher its value the greater the probability of the premise having the presence of Aedes aegypti. This study aimed to evaluate if there is a correspondence between PCI and Ae. aegypti infestation in four areas of a large city in the State of São Paulo, Brazil, if the inclusion of new categories related to the presence of animals in premises would increase the probability of detecting predictive areas for vector control actions and, if so, to propose an expanded PCI. The positivity of the premises for the presence of Ae. aegypti was modeled considering a Bernoulli probability distribution, in a Bayesian context using the Integrated Nested Laplace Approximation. The study showed that, in general, the higher the value of the PCI of a premise, the more likely it is to have the presence of Ae. aegypti, and the inclusion of information on the animals' presence can increase the discriminatory power of PCI. These results support the proposition of an extended PCI that would consider, in addition to the conditions of the premise, the presence of animals to classify it regarding the risk of the presence of Ae. aegypti.

Influence of strategic points in the dispersion of Aedes aegypti in infested areas.

OBJECTIVE: To evaluate whether sites with large amount of potential breeding sites for immature forms of Aedes aegypti, called strategic points, influence in the active vector's dispersion into properties in their surroundings. METHODS: We selected four areas in the municipality of Campinas, three of them with strategic points classified as high, moderate, and low risk according to infestation and a control area, without strategic points. Between October 2015 and September 2016, we monthly installed oviposition traps and evaluated the infestation by Ae. aegypti in all properties of each selected area. To verify if there was vector dispersion from each strategic point, based on its location, we investigated the formation of clusters with excess of eggs or larvae or pupae containers, using the Gi spatial statistics. RESULTS: The amount of eggs collected in the ovitraps and the number of positive containers for Ae. aegypti did not show clusters of high values concerning its distance from the strategic point. Both presented random distribution not spatially associated with the positioning of strategic points in the area. CONCLUSIONS: Strategic points are not confirmed as responsible for the vector's dispersion for properties in their surroundings. We highlight the importance of reviewing the current strategy of the vector control program in Brazil, seeking a balance from the technical, operational, and economic point of view, without disregarding the role of strategic points as major producers of mosquitoes and their importance in the dissemination of arboviruses in periods of transmission.

Influence of strategic points in the dispersion of Aedes aegypti in infested areas / Influência de pontos estratégicos na dispersão de Aedes aegypti em áreas infestadas

ABSTRACT OBJECTIVE: To evaluate whether sites with large amount of potential breeding sites for immature forms of Aedes aegypti, called strategic points, influence in the active vector's dispersion into properties in their surroundings. METHODS: We selected four areas in the municipality of Campinas, three of them with strategic points classified as high, moderate, and low risk according to infestation and a control area, without strategic points. Between October 2015 and September 2016, we monthly installed oviposition traps and evaluated the infestation by Ae. aegypti in all properties of each selected area. To verify if there was vector dispersion from each strategic point, based on its location, we investigated the formation of clusters with excess of eggs or larvae or pupae containers, using the Gi spatial statistics. RESULTS: The amount of eggs collected in the ovitraps and the number of positive containers for Ae. aegypti did not show clusters of high values concerning its distance from the strategic point. Both presented random distribution not spatially associated with the positioning of strategic points in the area. CONCLUSIONS: Strategic points are not confirmed as responsible for the vector's dispersion for properties in their surroundings. We highlight the importance of reviewing the current strategy of the vector control program in Brazil, seeking a balance from the technical, operational, and economic point of view, without disregarding the role of strategic points as major producers of mosquitoes and their importance in the dissemination of arboviruses in periods of transmission.

RESUMO OBJETIVO: Avaliar se locais com grande quantidade de potenciais criadouros de formas imaturas de Aedes aegypti, denominados pontos estratégicos, influenciam a dispersão ativa do vetor aos imóveis no seu entorno. MÉTODOS: Foram selecionadas quatro áreas no município de Campinas, três delas com pontos estratégicos classificados como alto, médio e baixo risco segundo a infestação e uma área controle, sem ponto estratégico. Entre outubro de 2015 e setembro de 2016, instalaram-se mensalmente armadilhas de oviposição e avaliou-se a infestação por Ae. aegypti em todos os imóveis de cada área selecionada. Para verificar se houve dispersão do vetor a partir de cada ponto estratégico, com base em sua localização, investigou-se a formação de aglomerados com excesso de ovos ou de recipientes com larvas ou pupas, utilizando a estatística espacial Gi. RESULTADOS: o número de ovos coletados nas ovitrampas e o número de recipientes positivos para Ae. aegypti não apresentaram aglomerados de altos valores relativos à sua distância do ponto estratégico. Ambos apresentaram distribuição aleatória não associada espacialmente com o posicionamento dos pontos estratégicos na área. CONCLUSÕES: Pontos estratégicos não se confirmaram como responsáveis pela dispersão do vetor para os imóveis no seu entorno. Destaca-se a importância de rever a estratégia atual do programa de controle de vetores do Brasil, buscando um equilíbrio do ponto de vista técnico, operacional e econômico, sem desconsiderar o papel dos pontos estratégicos como grandes produtores de mosquitos e sua importância na disseminação de arboviroses em momentos de transmissão.

Fitting the Incidence Data from the City of Campinas, Brazil, Based on Dengue Transmission Modellings Considering Time-Dependent Entomological Parameters.

Four time-dependent dengue transmission models are considered in order to fit the incidence data from the City of Campinas, Brazil, recorded from October 1st 1995 to September 30th 2012. The entomological parameters are allowed to depend on temperature and precipitation, while the carrying capacity and the hatching of eggs depend only on precipitation. The whole period of incidence of dengue is split into four periods, due to the fact that the model is formulated considering the circulation of only one serotype. Dengue transmission parameters from human to mosquito and mosquito to human are fitted for each one of the periods. The time varying partial and overall effective reproduction numbers are obtained to explain the incidence of dengue provided by the models.

Density of Aedes aegypti and Aedes albopictus and its association with number of residents and meteorological variables in the home environment of dengue endemic area, São Paulo, Brazil.

BACKGROUND: Measure the populations of Ae. aegypti and Ae. albopictus adults according to sex and location inside or outside the residence, estimate Ae. aegypti female density per house and per resident, and test the association with abiotic factors. METHODS: Adult mosquitoes were collected monthly with a hand net and portable electric catcher in the peridomiciliary and intradomiciliary premises of residences in an urban area with ongoing dengue transmission in the municipality of São Sebastião, Brazil, from February 2011 to February 2012. RESULTS: Of the 1,320 specimens collected, 1,311 were Ae. aegypti, and nine were Ae. albopictus. A total of 653 male and 658 female of Ae. aegypti were recorded, of which 80% were intradomiciliary. The mean density of Ae. aegypti adult females was 1.60 females/house and 0.42 females/resident. There was an association between the number of females and the number of residents in both intradomiciliary and peridomiciliary premises (r(2) = 0.92; p < 0.001 and r(2) = 0.68; p < 0.001, respectively). There was an association between the number of females and the mean and total rainfall; the correlation was better in peridomiciliary premises (p = 0.00; r(2) = 77%) than intradomiciliary premises in both cases (p = 0.01; r(2) = 48%). Minimum temperature was associated in both environments, exhibiting the same coefficient of determination (p = 0.02; r(2) = 40%). The low frequency of Ae. albopictus (seven females and two males) did not allow for detailed evaluation. CONCLUSIONS: Ae. aegypti is well established within the urban area studied, and the frequency of isolation is higher inside the houses. Female density was directly proportional to the number of residents in the houses. Our data show that human population density positively affects the number of Ae. aegypti females within the residence. Meteorological variables also affected mosquito populations. These data indicate a high probability of human-vector contact, increasing the possible transmission and spread of the DEN virus. Entomological indicators of adult females revealed important information complimenting what was obtained with traditional Stegomyia indices. This information should be a part of an interconnected data set for evaluating and controlling the vector.

Spatial distribution of the risk of dengue and the entomological indicators in Sumaré, state of São Paulo, Brazil.

Dengue fever is a major public health problem worldwide, caused by any of four virus (DENV-1, DENV-2, DENV-3 and DENV-4; Flaviviridae: Flavivirus), transmitted by Aedes aegypti mosquito. Reducing the levels of infestation by A. aegypti is one of the few current strategies to control dengue fever. Entomological indicators are used by dengue national control program to measure the infestation of A. aegypti, but little is known about predictive power of these indicators to measure dengue risk. In this spatial case-control study, we analyzed the spatial distribution of the risk of dengue and the influence of entomological indicators of A. aegypti in its egg, larva-pupa and adult stages occurring in a mid-size city in the state of São Paulo. The dengue cases were those confirmed by the city's epidemiological surveillance system and the controls were obtained through random selection of points within the perimeter of the inhabited area. The values of the entomological indicators were extrapolated for the entire study area through the geostatistical ordinary kriging technique. For each case and control, the respective indicator values were obtained, according with its geographical coordinates and analyzed by using a generalized additive model. Dengue incidence demonstrated a seasonal behavior, as well as the entomological indicators of all mosquito's evolutionary stages. The infestation did not present a significant variation in intensity and was not a limiting or determining factor of the occurrence of cases in the municipality. The risk maps of the disease from crude and adjusted generalized additive models did not present differences, suggesting that areas with the highest values of entomological indicators were not associated with the incidence of dengue. The inclusion of other variables in the generalized additive models may reveal the modulatory effect for the risk of the disease, which is not found in this study.

Study of the distribution and abundance of the eggs of Aedes aegypti and Aedes albopictus according to the habitat and meteorological variables, municipality of São Sebastião, São Paulo State, Brazil.

BACKGROUND: This study focused on the distribution and abundance of the eggs of Aedes aegypti and Aedes albopictus. METHODS: Eighty ovitraps were exposed for four days of each month in peri- and intradomiciliary environments of 40 urban residences on 20 street blocks that were drawn monthly in Sebastião, SP, between February 2011 and February 2012. The monthly distribution of positive ovitrap indices (POI) and mean egg counts per trap (MET) of Ae. aegypti and Ae. albopictus were analyzed using the Kruskal-Wallis test, followed by the Dwass-Steel-Critchlow-Fligner (DSCF) test. Spearman's rank correlation coefficient and simple linear regression were used to determine the association between the meteorological variables of temperature and rainfall and the number of ovitraps with eggs and the egg count. RESULTS: The POI and MET of Ae. aegypti were higher in peridomiciliary premises. A positive correlation was found between the temperature and the number of ovitraps with eggs and the egg count of this species in domestic environments. There was no difference in the POI and MET of Ae. albopictus between the environments. A positive correlation was found between temperature and positive ovitraps of Ae. albopictus in peridomiciliary premises. The POI and MET of Ae. aegypti were higher than those of Ae. albopictus. CONCLUSIONS: Peridomiciliary premises were the preferred environments for oviposition of Ae. aegypti. The use of ovitraps for surveillance and vector control is reiterated.

Infestação por Aedes aegypti em imóveis fechados nas visitas para vigilância e controle vetorial de dengue em municípios do Estado de São Paulo / Analyses of the Aedes aegypti infestation in buildings found closed in the dengue surveillance and vector control visits in two municipalities of São Paulo

Avaliou-se o impacto dos imóveis fechados na eficácia das atividades devigilância e controle do Aedes aegypti nos municípios de Guarujá e Hortolândia.Durante a atividade de monitoramento da infestação larvária nos meses de maio e novembro de 2008, os imóveis fechados foram caracterizados e revisitados aos finais de semana. Em maio, 29.9% dos imóveis estavam fechados no Guarujá e 32.9% em Hortolândia, em novembro esta proporção foi de 12.6% e 35.4%,respectivamente. Em Hortolândia, cerca de 90% dos imóveis fechados foramclassificados como Dormitório e no Guarujá, aproximadamente 45% foramclassificados como Dormitório e 45% como Outros. Observou-se que no geral apositividade do grupo de imóveis fechados na primeira visita e trabalhados na revisita, foi maior que a positividade registrada no grupo de imóveis trabalhados na primeira visita, porém, a diferença foi significativa somente no mês de maio em Guarujá. Com relação aos recipientes, em Guarujá houve predominância de ralos, material inservível e vaso de planta e prato, e em Hortolândia, os principais recipientes foram: material inservível e vaso de planta e prato. As informaçõesanalisadas apontam diferentes características entre os dois municípios/regiões, as quais devem ser consideradas para a adoção de estratégias visando melhorar osresultados das atividades de vigilância e controle de dengue

Spatial distribution of the risk of dengue fever in southeast Brazil, 2006-2007.

BACKGROUND: Many factors have been associated with circulation of the dengue fever virus and vector, although the dynamics of transmission are not yet fully understood. The aim of this work is to estimate the spatial distribution of the risk of dengue fever in an area of continuous dengue occurrence. METHODS: This is a spatial population-based case-control study that analyzed 538 cases and 727 controls in one district of the municipality of Campinas, São Paulo, Brazil, from 2006-2007, considering socio-demographic, ecological, case severity, and household infestation variables. Information was collected by in-home interviews and inspection of living conditions in and around the homes studied. Cases were classified as mild or severe according to clinical data, and they were compared with controls through a multinomial logistic model. A generalized additive model was used in order to include space in a non-parametric fashion with cubic smoothing splines. RESULTS: Variables associated with increased incidence of all dengue cases in the multiple binomial regression model were: higher larval density (odds ratio (OR) = 2.3 (95%CI: 2.0-2.7)), reports of mosquito bites during the day (OR = 1.8 (95%CI: 1.4-2.4)), the practice of water storage at home (OR = 2.5 (95%CI: 1.4, 4.3)), low frequency of garbage collection (OR = 2.6 (95%CI: 1.6-4.5)) and lack of basic sanitation (OR = 2.9 (95%CI: 1.8-4.9)). Staying at home during the day was protective against the disease (OR = 0.5 (95%CI: 0.3-0.6)). When cases were analyzed by categories (mild and severe) in the multinomial model, age and number of breeding sites more than 10 were significant only for the occurrence of severe cases (OR = 0.97, (95%CI: 0.96-0.99) and OR = 2.1 (95%CI: 1.2-3.5), respectively. Spatial distribution of risks of mild and severe dengue fever differed from each other in the 2006/2007 epidemic, in the study area. CONCLUSIONS: Age and presence of more than 10 breeding sites were significant only for severe cases. Other predictors of mild and severe cases were similar in the multiple models. The analyses of multinomial models and spatial distribution maps of dengue fever probabilities suggest an area-specific epidemic with varying clinical and demographic characteristics.

Avaliação da atividade de controle químico de vetores com ultra baixo volume em áreas com transmissão de dengue dos municípios de Hortolândia e Sumaré, SP / An evaluation of ultra low volume inseticide sprays application for dengue control in areas of Hortalândia and Sumaré municipalities, SP, Brazil

A epidemia de dengue ocorrida no verão de 2006/2007 foi a maior registrada no Estado de São Paulo, até então. Os municípios de Hortolândia e Sumaré apresentaram níveis importantes detransmissão. Para reduzir rapidamente a quantidade de mosquitos alados e auxiliar a interrupção da transmissão nas áreas com maior número de casos, a Sucen organizou equipes para realizar aplicação domiciliar de inseticida a ultra baixo volume (UBV) com atomizadorescostais portáteis, complementando as atividades dos municípios, que eram principalmente de eliminação dos criadouros. Este estudo tem como objetivo avaliar o trabalho dessas equipes, realizado em abril de 2007, nos municípios citados. Em Hortolândia, realizou-se estudo descritivo comparando-se medições de infestação e de ocorrência de casos antes e depois das referidas atividades. Em Sumaré, foi avaliada apenas a ocorrência de casos, tendo sido realizado inquérito paraavaliar a opinião das pessoas sobre a atividade. Observou-se quehouve redução acentuada na positividade e densidade de ovos nasarmadilhas, instaladas na semana seguinte à realização da atividadede controle químico. Na segunda semana já ocorreu um aumento na positividade e densidade de ovos. Não se pôde determinar o efeito da nebulização domiciliar sobre o número de casos porque ela foi realizada com a transmissão já em queda. A aceitação e avaliação do efeito da atividade pela população são boas. Concluiu-se que para que essas medidas sejam efetivas a remoção dos criadouros tem de serdrástica e se repetir nas semanas seguintes auxiliada por um trabalhoeducativo intenso para evitar a formação de novos criadouros

Distribuição espacial do risco de dengue em região do município de Campinas

A necessidade de obter dados para o entendimento da transmissão de dengue em uma área do município de Campinas-SP foi o objetivo deste trabalho que teve como estudo um caso-controle espacial onde foi possível avaliar a distribuição espacial do risco de dengue em 2007. Para tanto foram realizadas entrevistas em campo e avaliadas co-variáveis de interesse do estudo como: socioeconômicas, epidemiológicas e entomológicas, em moradores, do Distrito Sul e que adquiriram dengue no período do estudo. Foram 539 casos e 740 controles distribuídos na região de estudo. Todos os casos e controle foram localizados em mapa digital, através de coordenadas geográficas e ajustados em um modelo aditivo generalizado. Os resultados mostram que mesmo com as dificuldades encontradas, no período do estudo, foram satisfatórios e comprovaram a necessidade de investimento em saneamento, educação, mobilização social e melhoria em unidades de saúde de risco de introdução do vírus e dispersão deste para outras áreas do distrito e município...

Distribuição espacial do risco de dengue em região do municipio de Campinas / Spatial distribution for risk of dengue fever in a region of the municipality of Campinas

A necessidade de obter dados para o entendimento da transmissão de dengue em uma área do município de Campinas - SP foi o objetivo deste trabalho que teve como estudo um caso-controle espacial onde o foi possível avaliar a distribuição espacial do risco de dengue em 2007. Para tanto foram realizadas entrevistas em campo e avaliadas co-variáveis de interesse do estudo como: socioeconômicas, epidemiológicas e entomológicas, em moradores, do Distrito Sul e que adquiriram dengue no período do estudo. Foram 539 casos e 740 controles distribuídos na região de estudo. Todos os casos e controle foram localizados em mapa digital, através de coordenadas geográficas e ajustados em um modelo aditivo generalizado. Os resultados mostram que mesmo com as dificuldades encontradas, no período de estudo, foram satisfatórios e comprovaram a necessidade de investimento em saneamento, educação, mobilização social e melhoria em unidades de saúde de risco de introdução do vírus e dispersão deste para outras áreas do distrito e município.

The need to obtain data for understanding transmission of dengue fever in an area of the municipality of Campinas-SP was the objective of the present spatial case-control study in which it was possible to evaluate the spatial distribution of risk for dengue fever in 2007. Toward that end, field interviews were carried out and co-variables of interest to the study were assessed: socioeconomic, epidemiological and entomologic, in dwellers of the South District and who acquired dengue during the study period. There were 539 cases and 740 controls distributed in the study region. All cases and controls were found on a digital map, using geographic coordinates adjusted in a generalized additive model. Results, albeit difficulties found during the study period, were satisfactory and showed the need for investments in sanitation, education, social mobilization and improvement in units with health risk for introduction of the virus and its spread to other areas of the district and municipality.

[Dengue: sero-epidemiological survey and virological surveillance in Campinas, São Paulo, Brazil]. / Dengue: inquérito populacional para pesquisa de anticorpos e vigilância virológica no Município de Campinas, São Paulo, Brasil.

The epidemiology of dengue in the municipality of Campinas, São Paulo, Brazil, was studied in 1998 using a randomized sero-epidemiological survey. Epidemiological surveillance data from 1996-2003 were also analyzed, with an emphasis on virological surveillance. 1,260 individuals participated in the survey and had blood samples drawn by finger stick on filter paper. Blood samples were tested by EIA-ICC, an enzyme immunoassay using infected cells as antigen. Dengue antibody prevalence (14.79%) was lower than in other surveys in other States of Brazil, but higher than in two other serological surveys in São Paulo State. Dengue antibody prevalence was far higher than the reported case incidence during the 1996, 1997, and 1998 epidemics. Antibody prevalence and reported case incidence in different health districts were disproportional. The article concludes by recommending further research on the significance of transmission rates during epidemics and more intensive virological surveillance, especially in years with few reported cases.

Dengue: inquérito populacional para pesquisa de anticorpos e vigilância virológica no Município de Campinas, São Paulo, Brasil / Dengue: sero-epidemiological survey and virological surveillance in Campinas, Sao Paulo, Brazil

Estudou-se a epidemiologia do dengue no Município de Campinas, São Paulo, Brasil, por meio de um inquérito populacional aleatório realizado em 1998, visando à detecção dos níveis de anticorpos para dengue, e de dados de vigilância epidemiológica do período de 1996 a 2003, com ênfase na vigilância virológica. Foram coletadas 1.260 amostras, por meio de punção digital, utilizando-se papel de filtro, sendo as amostras testadas pelo teste imunoenzimático em culturas celulares infectadas (EIA-ICC). Observou-se que a prevalência de soro reagentes (14,79 por cento) é mais baixa que as encontradas em outros inquéritos realizados no país e superior às encontradas em dois inquéritos realizados em cidades do Estado de São Paulo. Detectou-se uma prevalência de soro reagentes muito superior à incidência de casos notificados e confirmados laboratorialmente durante as epidemias de 1996, 1997 e 1998. Não se encontrou proporcionalidade entre a prevalência de anticorpos para dengue e a incidência de casos durante a epidemia nos diferentes Distritos de Saúde da cidade. Sugerem-se um estudo aprofundado do significado dos indicadores de transmissão utilizados em epidemias e uma vigilância virológica mais intensa, principalmente em anos com níveis de transmissão baixos.

The epidemiology of dengue in the municipality of Campinas, São Paulo, Brazil, was studied in 1998 using a randomized sero-epidemiological survey. Epidemiological surveillance data from 1996-2003 were also analyzed, with an emphasis on virological surveillance. 1,260 individuals participated in the survey and had blood samples drawn by finger stick on filter paper. Blood samples were tested by EIA-ICC, an enzyme immunoassay using infected cells as antigen. Dengue antibody prevalence (14.79 percent) was lower than in other surveys in other States of Brazil, but higher than in two other serological surveys in São Paulo State. Dengue antibody prevalence was far higher than the reported case incidence during the 1996, 1997, and 1998 epidemics. Antibody prevalence and reported case incidence in different health districts were disproportional. The article concludes by recommending further research on the significance of transmission rates during epidemics and more intensive virological surveillance, especially in years with few reported cases.

Utilização de sistema de informações geográficas na rotina de controle da dengue / The use of geographic information system in routine dengue control

O uso de mapas é imprescindível para o planejamento e o controle da dengue. A disponibilidade de um Sistema de Informações Geográficas (SIG) facilita estas ações. O objetivo desse artigo é demonstrar a viabilidade de utilizar o SIG para facilitar as atividades de planejamento e controle da dengue na rotina do dia-a-dia. Relata-se a experiência de utilização de um SIG na rotina de avaliação e controle da doença no município de Campinas, no período de novembro de 2002 a junho de 2003. Utilizou-se mapa digital com eixo de ruas existente na prefeitura e banco com os dados dos casos confirmados laboratorialmente. Foi implantado um SIG nas instituições responsáveis pelo controle da doença. Estabeleceram-se rotinas para as várias etapas do processo de utilização dos dados no SIG. Os casos foram georreferenciados por endereço de porta. Foram apontadas as contribuições do SIG no processo rotineiro de avaliação, planejamento e controle da dengue e, também, as dificuldades encontradas.