Effects of Urban Growth on the Cases of Dengue Fever and Changes in Landscape Structure: A Case Study

Introduction. Urban growth can negatively affect the health of the population when planning measures are not done properly. Landscape analysis using spatial analysis techniques can provide tools for a better urban planning, allowing a better quality of life and preservation of natural areas. Dengue outbreaks in major cities have among other factors, urban sprawl, high-number of breeding sites for mosquitoes, high temperatures and large numbers of susceptible persons. Objective/Methods. The aim of this study is to analyze the spatial and temporal dynamics of dengue fever in the city of Coronel Fabriciano, Minas Gerais State, Brazil, a mid-sized city with 100,000 inhabitants, and to associate cases to the growth of urban areas and loss of natural areas in recent years. Results. The landscape showed changes in the units of urban area and pasture in the period between 1989 and 2009. We observed an urban growth over the pasture matrix. No changes were observed in the areas of remaining forest and eucalyptus. 8333 dengue cases were reported between 2002 and 2009 and geocoded in GIS environment. There is a grouping of cases in space with a tendency to form clusters, detected by using the function-k. LISA analysis has shown a tendency for clustering when cases were analyzed as incidence rates in each census tract in the city. Conclusion. We observed cases of dengue spatially clustered in the northern region where new neighborhoods have emerged in recent years following the population growth without proper structure of urbanization and urban planning. In addition, urban growth has led to an approach to native forest fragments with more edge effects, reduced the margin of watercourses and providing a bare soil, suitable for accumulation of trash and formation of breeding sites for mosquitoes. Efficient public policies and appropriate urban planning might reduce the impact of dengue fever.