Aspectos da paisagem e fatores socioeconômicos nos casos de dengue na cidade de Porto Alegre, RS (Landscape aspects and socioeconomic factors in the cases of Dengue in the city of Porto Alegre, RS)

A dengue e uma doenca causada por um arbovirus transmitido pelo mosquito Aedes aegypti . Nas areas urbanas, a falta de planejamento ambiental e a desigualdade das condicoes socioeconomicas favoreceram o aumento dos casos da doenca, mesmo em locais com clima mais variavel, como o sul do Brasil. Em 2001, houve a introducao de A. aegypti na cidade de Porto Alegre, RS. Objetivou-se correlacionar casos de dengue autoctones com variaveis socioeconomicas e ambientais em Porto Alegre. No periodo de janeiro a julho de 2013 monitoraram-se 712 armadilhas para mosquitos adultos, em 22 bairros da cidade. Para analise de variaveis ambientais, recorreu-se aos dados de cobertura e uso do solo para cada bairro amostrado, conforme as seguintes classes: cobertura vegetal (arvores, arbustos e herbaceos), agua e uso humano (outros usos). Utilizaram-se como variaveis, a cobertura e uso do solo, precipitacao, temperatura, renda media e a densidade populacional por bairro. Aplicou-se a analise de regressao multipla para avaliar a importância de cada fator em relacao ao numero de femea e casos relatados. Os resultados indicam que a precipitacao nao influenciou significativamente o numero de femeas coletadas, mas a temperatura tem uma relacao significativa. O numero de femeas coletadas eleva-se com o aumento da temperatura. A analise de regressao multipla indica que a variavel dependente (numero de casos) foi significativamente influenciada pelo numero de femeas (p = 0,0420), a cobertura vegetal (p = 0,0005) e o uso antropico (p = 0,0003). A B S T R A C T The dengue is a disease caused by an arbovirosis transmitted by the mosquito Aedes aegypti . In urban areas, the lack of environmental planning and difference in socioeconomic conditions have favored an increase in the disease cases even in places with milder weather, such as southern Brazil. In 2001, there was the introduction of A. aegypti in the city of Porto Alegre, RS. The aim of the study was to correlate cases of autochthonous dengue with socioeconomic and environmental variables in Porto Alegre. From January to July 2013, 712 traps for adult mosquitoes were monitored in 22 city neighborhoods. For analysis of environmental variables, data of use and land cover were obtained for each sampled neighborhood and separated into the following classes: vegetation cover (trees, shrubs and herbaceous), water and human use (other uses). Besides the land use and cover the influence of rainfall, temperature, average income and population density have been verified. Multiple regression analysis was performed to assess the importance of each factor in the number of reported cases. The results indicated that precipitation did not significantly influence the number of females collected, but the temperature has a significant relationship. The number of females collected increases with increasing temperature. The multiple regression analysis indicates that the dependent variable (number of cases) was significantly influenced by the number of females (p = 0.0420), the vegetation cover (p = 0.0005) and human use (p = 0.0003 ), but the density and average income. Keywords: Coverage and land use; ArcGis; geoprocessing; image processing; environmental health surveillance.