Dengue em Araraquara, SP: epidemiologia, clima e infestação por Aedes aegypti

OBJETIVO: Descrever a epidemiologia da dengue em cidade de médio porte do estado de São Paulo. MÉTODOS: Foram obtidas informações sobre os casos notificados e confirmados de dengue em Araraquara, SP, entre 1991 e 2015, como sorotipos circulantes, casos graves e óbitos, faixa etária, sexo, entre outras. Também foram levantadas as informações climáticas e de infestação pelo vetor. Essas variáveis foram trabalhadas descritivamente, utilizando-se medidas estatísticas como frequências, médias, mínimo e máximo. Calcularam-se taxas de incidência de dengue segundo mês, ano, idade e sexo, e série histórica de casos de dengue, infestação e variáveis climáticas. RESULTADOS: Foram confirmados 16.431 casos de dengue entre 1991 e 2015. O maior número de notificações foi registrado em 2015 (7.811 casos). De forma geral, a faixa etária com o maior número de notificações encontra-se entre 20 e 59 anos. As maiores incidências, geralmente entre março e maio, ocorreram após o aumento da pluviosidade e infestação, em janeiro. CONCLUSÕES: Os altos níveis de infestação que aumentam com as chuvas refletem-se nas taxas de incidência da doença. É fundamental conhecer a epidemiologia da dengue em cidades de médio porte. Seus resultados podem ser estendidos para doenças como Zika e Chikungunya (transmitidas pelo mesmo vetor e notificadas na cidade). A intensificação dos esforços de vigilâncias em períodos que precedem as epidemias poderia ser uma estratégia a ser considerada para o controle da dispersão viral.OBJECTIVE: To describe the epidemiology of dengue in a medium-sized city in the state of São Paulo. METHODS: Data, such as circulating serotypes, severe cases and deaths, age group, sex, among others, were obtained on reported and confirmed dengue cases in Araraquara, state of São Paulo, between 1991 and 2015. Climatic and infestation data were also analyzed. These variables were evaluated descriptively, using statistical measures such as frequencies, averages, minimum and maximum. Dengue incidence rates were calculated according to month, year, age and sex, and time series of dengue cases, infestation, and climatic variables. RESULTS: Approximately 16,500 cases of dengue fever were reported between 1991 and 2015. The highest number of reports was recorded in 2015 (7,811 cases). In general, the age group with the highest number of reports is between 20 and 59 years old. The highest incidences, generally between March and May, occurred after the increase in rainfall and infestation in January. CONCLUSIONS: Increased levels of infestation due to rainfall are reflected in incidence rates of the disease. It is fundamental to know the epidemiology of dengue in medium-sized cities. Such information can be extended to diseases such as Zika and Chikungunya, which are transmitted by the same vector and were reported in the city. The intensification of surveillance efforts in periods before epidemics could be a strategy to be considered to control the viral spread

Modelo de risco tempo-espacial para identificação de áreas de risco para ocorrência de dengue

OBJECTIVE: To apply the temporal-spatial model to assess high-risk areas for the occurrence of dengue fever. METHODS: A total of 11,989 confirmed, autochthonous dengue fever cases, geocoded by address in the city of São José do Rio Preto (Southeastern Brazil), between September of 2001 and August of 2006, were included in the study. Frequency, duration and intensity indices were used to assess the severity and magnitude of transmission. The local indicator of spatial association was adopted to identify significant spatial clusters (p-valueOBJETIVO: Aplicar o modelo tempo-espacial para avaliar áreas de risco para a ocorrência de dengue. MÉTODOS: Foram considerados os 11.989 casos de dengue confirmados e autóctones, georreferenciados por endereço em São José do Rio Preto entre setembro de 2001 e agosto de 2006. Para avaliar a severidade e a magnitude da transmissão foram adotados índices de freqüência, duração e intensidade. O indicador local de autocorrelação espacial foi adotado para identificar agrupamentos espaciais significantes (

Variáveis socioeconômicas e a transmissão de dengue

OBJECTIVE: To evaluate the relationship between risk of occurrence of dengue and socioeconomic level. METHODS: All confirmed autochthonous cases of dengue between September 1990 and August 2002 were geocoded and grouped according to the urban census tracts of the municipality of São José do Rio Preto, Southeastern Brazil. A socioeconomic factor generated by principal component analysis was used to group census tracts into four socioeconomic levels. Incidence rates were calculated for each year and four-year period for each of the census sectors, considering the period from September of one year to August of the next. Thematic maps of sectors, grouped into each of the four socioeconomic levels and their respective disease incidences, are presented. RESULTS: Principal component analysis generated a socioeconomic factor that accounted for 87% of total variation. This factor was associated with dengue incidence only for the 1994-95 period. CONCLUSIONS: The lack of an association between risk of occurrence of dengue and socioeconomic levels in almost all years studied indicates that this issue deserves further study, and may vary depending on the settings found in each municipality. It will be important to determine the spatial relationship between dengue transmission and other variables, such as degree of immunity in the population, effectiveness of control measures, degree of infestation by the vector; and population habits and behaviors, among others.OBJETIVO: Avaliar a relação entre o risco de ocorrência de dengue e os níveis socioeconômicos. MÉTODOS: Os casos autóctones de dengue confirmados entre setembro de 1990 a agosto de 2002 foram geocodificados e agrupados segundo setores censitários urbanos de São José do Rio Preto, estado de São Paulo. Um fator socioeconômico foi gerado por meio da técnica de análise de componentes principais, agrupando os setores censitários em quatro níveis socioeconômicos. Os coeficientes de incidência foram calculados, por ano e quadriênio, para cada um dos agrupamentos de setores censitários, considerando-se o período entre setembro de um ano a agosto do ano seguinte. São apresentados mapas temáticos dos setores agrupados nos quatro níveis socioeconômicos com os respectivos coeficientes de incidência da doença. RESULTADOS: A análise de componentes principais produziu um fator socioeconômico responsável por 87% da variação total. Esse fator esteve associado com as incidências de dengue apenas no ano de 1994-1995. CONCLUSÕES: A ausência de associação encontrada entre risco de ocorrência de dengue e níveis socioeconômicos na quase totalidade dos anos estudados mostra que esta é uma questão que precisa ser mais bem estudada e, talvez, dependa da realidade de cada município. É importante que sejam verificadas as relações espaciais entre a transmissão de dengue e outras variáveis, como o grau de imunidade da população; a efetividade das medidas de controle; o grau de infestação pelo vetor; os hábitos e atitudes da população, entre outros

Infestação de área urbana por Aedes aegypti e relação com níveis socioeconômicos

OBJECTIVE: To assess the association between Aedes aegypti larvae infestation rates and socioeconomic factors. METHODS: Infestation rates in the urban area of the city of São José do Rio Preto, Southeastern Brazil, were calculated in January of 2005 and subsequently geocoded by address. The urban census tracts were grouped by means of main component analysis, thus producing four socioeconomic clusters (1-4, in a decreasing order of socioeconomic level) and a fifth cluster (5) with a level below the others and not belonging to the urban census tracts (new districts and irregular residential development projects). The Breteau index (BI), the house index (HI), and the container index (CI), as well as the averages of existing containers surveyed per home, were calculated for each cluster. RESULTS: The values of infestation indices did not show significant differences among socioeconomic clusters 1 to 4, even though they were lower than the indices obtained for cluster 5. The averages of existing containers surveyed were higher for cluster 1 in relation to clusters 2 to 4, but did not show significant differences when compared to cluster 5. CONCLUSIONS: Larval indices did not show association with the different socioeconomic levels of the cluster that corresponds to the urban census tracts. Nonetheless, new districts, irregular residential development projects and locations adjacent to those with the worst basic sanitary conditions showed the highest values for these indicators.OBJETIVO: Analisar a associação entre índices de infestação larvária por Aedes aegypti e fatores socioeconômicos. MÉTODOS: Foram calculados os índices de infestação na área urbana de São José do Rio Preto, São Paulo, em janeiro de 2005 e em seguida geocodificados por endereço. Os setores censitários urbanos foram agrupados por meio de análise de componentes principais, produzindo quatro áreas socioeconômicas (1-4, ordem decrescente de nível socioeconômico) e um quinto agrupamento (5) com nível inferior aos demais e não pertencente aos setores censitários urbanos (bairros novos e loteamentos irregulares). Calcularam-se, para cada área, os índices de Breteau (IB), predial (IP) e de recipientes (IR), e as médias de recipientes existentes e pesquisados por casa. RESULTADOS: Os valores dos índices de infestação não apresentaram diferenças significativas entre as áreas socioeconômicas 1 a 4, mas foram menores que os índices obtidos para a área 5. As médias de recipientes existentes e pesquisados foram maiores para a área 1 em relação às áreas 2 a 4, mas não apresentaram diferenças significativas em relação à 5. CONCLUSÕES: Os índices larvários não mostraram associação com os diferentes níveis socioeconômicos da área correspondente aos setores censitários urbanos. Entretanto, os bairros novos, loteamentos irregulares e locais contíguos com as piores condições de saneamento básico apresentaram os maiores valores desses indicadores

How many AIDS epidemics can occur in São Paulo city?

OBJECTIVE: An ecological study describring the spatial characteristics of AIDS in São Paulo city between 2001 and 2010 according to the place of residence of reported cases in adults. METHODS: The AIDS reported cases (28,146), grouped by sex, were geocodified (25,969) and linked with a census tract database (18,953). Case and population at risk data supplied spatial cluster identification and relative risk estimate by the scan method, using the discrete Poisson model. Incidence rate and proportional distribution allowed comparing people living in the high-risk clusters areas to other locations by age, race/ethnicity, schooling and transmission category. RESULTS: The AIDS incidence rate decreased in both sexes except among young men and older people. The identification of spatial high-risk clusters showed that the decrease of AIDS did not occur in the same way in the city. Clusters located in the central area presented the highest AIDS incidence rates (245.7/100,000 men), especially among black women (RR = 7.9), men who have sex with men (66.2%) and injection drug users (10.7%) participation. In peripheral clusters, identified only in the female population, the epidemic can be related to the poverty of these women (22.5% low education level). Residents in the north and central-south areas of the city are generally black, with little schooling, and predominantly heterosexually infected. CONCLUSIONS: The study of spatial clusters using a census tract helps to determine epidemiological patterns inside the city and in specific populations. Spatial stratification and key population epidemiological patterns were identified in four regions in São Paulo cit

Finding Aedes aegypti in a natural breeding site in an urban zone, Sao Paulo, Southeastern Brazil

Descreve-se o encontro de nove larvas de Aedes aegypti em criadouro natural no bairro de Pinheiros, município de São Paulo, SP. O registro ocorreu no mês de dezembro de 2014, durante programa de vigilância entomológica dos vetores do vírus dengue, com busca ativa de potenciais criadouros, artificiais ou naturais. O encontro de larvas de Ae. aegypti em oco de árvore revela a capacidade dessa espécie de utilizar tanto criadouros artificiais como naturais para o seu desenvolvimento, o que aponta para a importância da manutenção de vigilância contínua sobre esse mosquito em todos os tipos de recipientes que podem acumular água.This is the description of how nine Aedes aegypti larvae were found in a natural breeding site in the Pinheiros neighborhood, city of Sao Paulo, SP, Southeastern Brazil. The record was conducted in December 2014, during an entomological surveillance program of dengue virus vectors, with an active search of potential breeding sites, either artificial or natural. Finding Ae. aegypti larvae in a tree hole shows this species’ ability to use both artificial and natural environments as breeding sites and habitats, which points towards the importance of maintaining continuous surveillance on this mosquito in all kinds of water-holding containers

Spatio-temporal dynamics of dengue-related deaths and associated factors

Since the reintroduction of dengue viruses in 1987, Sao Paulo State (SP), Brazil, has experienced recurrent epidemics in a growing number of municipalities, each time with more cases and deaths. In the present study, we investigated the spatio-temporal dynamics of dengue-related deaths and associated factors in SP. This was an ecological study with spatial and temporal components, based on notified dengue-related deaths in the municipalities of SP between 2007 and 2017. A latent Gaussian Bayesian model with Poisson probability distribution was used to estimate the standardized mortality ratios (SMR) for dengue and relative risks (RR) for the socioeconomic, demographic, healthcare-related, and epidemiological factors considered. Epidemiological factors included the annual information on the number of circulating serotypes. A total of 1,019 dengue-related deaths (0.22 per 100,000 inhabitant-years) between 2007 and 2017 were confirmed in SP by laboratory testing. Mortality increased with age, peaking at 70 years or older (1.41 deaths per 100,000 inhabitant-years). Mortality was highest in 2015, and the highest SMR values were found in the North, Northwest, West, and coastal regions of SP. An increase of one circulating serotype, one standard deviation in the number of years with cases, and one standard deviation in the degree of urbanization were associated with increases of 75, 35, and 45% in the risk of death from dengue, respectively. The risk of death from dengue increased with age, and the distribution of deaths was heterogeneous in space and time. The positive relationship found between the number of dengue serotypes circulating and years with cases at the municipality/micro-region level indicates that this information can be used to identify risk areas, intensify surveillance and control measures, and organize healthcare to better respond to this disease

Spatial analysis of pneumococcal meningitis in São Paulo in the pre- and post-immunization era

OBJECTIVE: To analyze the pneumococcal meningitis incidence rates in the State of São Paulo, Brazil, by age group, municipalities and micro-regions, as well as the spatial distribution of pneumococcal meningitis incidence rates among children under 5 years old in the pre- (2005–2009) and post-vaccination (2011–2013) periods and its associations with socioeconomic variables and vaccination coverage. METHODS: The data source was the Brazilian Notifiable Diseases Information System. For the pre- and post-vaccination periods, thematic maps were built for pneumococcal meningitis incidence in under-5 children, by São Paulo state micro-regions, vaccination coverage and socioeconomic variables, using QGIS 2.6.1 software. Scan statistics performed by the SatScan 9.2 software were used to analyze spatial and spatiotemporal clusters in São Paulo municipalities and micro-regions. A Bayesian inference for latent Gaussian model with zero-inflated Poisson model through the integrated nested Laplace approximation was used in the spatial analysis to evaluate associations between pneumococcal meningitis incidence rates and socioeconomic variables of interest in São Paulo micro-regions. RESULTS: From 2005 to 2013, 3,963 pneumococcal meningitis cases were reported in São Paulo. Under-5 children were the most affected in the whole period. In the post-vaccination period, pneumococcal meningitis incidence rates decreased among this population, particularly among infants (from 4.17/100,000 in 2005 to 2.54/100,000 in 2013). Two clusters were found in pre-vaccination – one of low risk for pneumococcal meningitis, in the northwest of the state (OR = 0.45, p = 0.0003); and another of high risk in the southeast (OR = 1.62, p = 0.0000). In the post-vaccination period, only a high-risk cluster remained, in the southeast (RR = 1.97, p = 0.0570). In Bayesian analysis, wealth was the only variable positively associated to pneumococcal meningitis (RR = 1.026, 95%CI 1.002–1.052). CONCLUSIONS: Pneumococcal meningitis is probably underdiagnosed and underreported in São Paulo. Differentiated rates of pneumococcal meningitis diagnosis and reporting in each microregion, according to the São Paulo Index of Social Responsibility, might explain our results

Aedes aegypti entomological indices in an endemic area for dengue in Sao Paulo State, Brazil

OBJETIVO: Avaliar os tipos de imóveis e de recipientes mais produtivos para o desenvolvimento de Aedes aegyptie a distribuição espacial de indicadores entomológicos. MÉTODOS: Foram realizadas coletas de formas imaturas de mosquitos para obtenção de indicadores entomológicos em 9.875 imóveis no bairro Jaguaré, no município de São José do Rio Preto, SP, entre dezembro de 2006 e fevereiro de 2007. Aplicou-se questionário sobre as condições e características de imóveis em março e abril de 2007. Utilizou-se regressão logística para identificar as variáveis associadas com a presença de pupas nos imóveis. Índices calculados por quadra foram combinados com mapas georreferenciados, possibilitando a produção de mapas temáticos por meio de interpolação estatística. RESULTADOS: Os imóveis inspecionados apresentaram os seguintes índices para Ae. aegytpi: Índice de Breteau de 18,9, 3,7 larvas e 0,42 pupas por imóvel, 5,2 recipientes com Ae. aegypti por hectare, 100,0 larvas e 11,6 pupas por hectare, e 1,3 larva e 0,15 pupa por habitante. Presença de quintal, jardim e animais associaram-se com a presença de pupas. CONCLUSÕES: Não foram identificados tipos específicos de imóveis e de recipientes que fossem pouco frequentes dentre aqueles com a presença do vetor e, ao mesmo tempo, que apresentassem elevada participação na produtividade de larvas e pupas. O uso de índices baseados na quantificação de larvas e pupas não traria informações além daquelas obtidas com os índices estegômicos tradicionais em localidades com características similares a São José do Rio Preto. Os índices calculados por área apresentaram maior acurácia para avaliar espacialmente a infestação, e a infestação por Ae. aegypti apresentou grande variabilidade espacial, apontando a necessidade de realizar avaliações de infestação em microáreas.OBJECTIVE: To evaluate the most productive types of properties and containers for Aedes aegypti and the spatial distribution of entomological indices. METHODS: Between December 2006 and February 2007, the vector's immature forms were collected to obtain entomological indices in 9,875 properties in the Jaguare neighborhood of Sao Jose do Rio Preto, SP, Southeastern Brazil. In March and April 2007, a questionnaire about the conditions and characteristics of properties was administered. Logistic regression was used to identify variables associated with the presence of pupae at the properties. Indices calculated per block were combined with a geo-referenced map, and thematic maps of these indices were obtained using statistical interpolation. RESULTS: The properties inspected had the following Ae. aegypti indices: Breteau Index = 18.9, 3.7 larvae and 0.42 pupae per property, 5.2 containers harboring Ae. aegypti per hectare, 100.0 larvae and 11.6 pupae per hectare, and 1.3 larvae and 0.15 pupae per inhabitant. The presence of yards, gardens and animals was associated with the presence of pupae. CONCLUSIONS: Specific types of properties and containers that simultaneously had low frequencies among those positive for the vector and high participation in the productivity of larvae and pupae were not identified. The use of indices including larval and pupal counts does not provide further information beyond that obtained from the traditional Stegomyia indices in locations with characteristics similar to those of São José do Rio Preto. The indices calculated per area were found to be more accurate for the spatial assessment of infestation. The Ae. aegypti infestation levels exhibited extensive spatial variation, indicating that the assessment of infestation in micro areas is needed.OBJETIVO: Evaluar los tipos de inmuebles y de recipientes más productivos para el desarrollo de Aedes aegypti y la distribución espacial de indicadores entomológicos MÉTODOS: Se realizaron colectas de formas inmaduras de mosquitos para obtención de indicadores entomológicos en 9.875 inmuebles en la urbanización Jaguaré, en el municipio de Sao José do Rio Preto, SP (Brasil), entre diciembre de 2006 y febrero de 2007. Se aplicó cuestionario sobre las condiciones y características de los inmuebles en marzo y abril de 2007. Se utilizó regresión logística para identificar las variables asociadas con la presencia de pupas en los inmuebles. Se combinaron los Índices calculados por cuadra con mapas georeferenciados, posibilitando la producción de mapas temáticos por medio de interpolación estadística. RESULTADOS: Los inmuebles inspeccionados presentaron los siguientes índices para Aedes aegypti: Índice de Breteau de 18,9, 3,7 larvas y 0,42 pupas por inmueble, 5,2 recipientes con Ae. Aegypti por hectárea, 100,0 larvas y 11,6 pupas por hectárea, y 1,3 larvas y 0,15 pupas por habitante. Presencia de patio, jardín y animales se asociaron con la presencia de pupas. CONCLUSIONES: No se identificaron tipos específicos de inmuebles y de recipientes que fueran poco frecuentes entre aquellos con la presencia del vector y, al mismo tiempo, que presentaran elevada participación en la productividad de larvas y pupas. El uso de índices basados en la cuantificación de larvas y pupas no traería informaciones aunadas a las obtenidas con los índices Stegómicos tradicionales en localidades con características similares a Sao José do Rio Preto. Los índices calculados por área presentaron mayor precisión para evaluar espacialmente la infestación y la infestación por Ae. Aegypti presentó gran variabilidad espacial, señalando la necesidad de realizar evaluaciones de infestación en micro áreas