Geographic Information System Data

Place is one of the basic tenets of a field investigation. Both the who and the when of infection are relative to and often dependent on the where. Geographic information science, systems, software (collectively known as GIS), and methods are among the tools epidemiologists use in defining and evaluating the where. This chapter reviews GIS applications as they pertain to the 10 steps of a field investigation. This chapter offers recommendations about the types of geographic data, equipment, and software necessary for GIS and provides considerations for visualization and spatial analysis. An overview is included of sample data sets that might prove useful for estimating and defining the population in a particular study area (e.g., population data from the US Census) as are recommendations for geospatial methods for estimating sociodemographic characteristics and disease rates by using these data within GIS. This chapter should provide field epidemiologists with a greater spatial awareness that will help guide the design, collection, analysis, and dissemination of findings from a field investigation.