GIS: Linking Public Health data and Geography GIS: Linking Public Health data and Geography
Centers for Disease Control and Prevention

A Geographic Information System (GIS) consists of computer hardware and software designed to collect, retrieve, and manipulate geographic data for use in analysis and planning. The Centers for Disease Control and Prevention use GIS to help make public health decisions based on associations between data and geography.

GIS plays an important role in public health promotion and protection by combining geographic facts gathered from multiple sources and displaying the resulting integrated data in images that show relationships between data and geography. CDC uses GIS in analyzing and understanding public health problems ranging from rates of chronic illness such as heart disease to identification of infectious diseases outbreak sources.

Using geographic data to help solve public health problems and to fight disease has a long history. In the past, physicians, scientists and epidemiologists plotted information, such as the location of known deaths from a disease, directly on paper maps and used that data to identify possible sources of contagion. Knowing where a disease began could help determine how it began and so how to stop its spread.

This remains true today, but modern GIS has become much more than a map-making system. GIS is now a collection of technologically sophisticated information management tools that can be used to display the data in whatever form makes the data easiest to understand and work with. This may still include maps but can also involve graphs, charts, tables, and other visual displays.

GIS allows analysts to layer information to show different combinations of data, to run comparisons, and to create models projecting possible future outcomes. GIS is used in planning responses to possible public health emergencies such as natural disasters, as well as to model how quickly an outbreak of an infectious disease might spread.

The geographic data that these systems use can include maps, global positioning satellite (GPS) coordinates for specific locations, demographic facts such as the population density of a region, political boundaries, and other factors describing geographic sites or regions. GIS allows public health professionals to take all the known geographic information for a site or region and look for patterns or relationships in that data. They may conduct further research to see if those patterns may be contributing factors to public health problems identified in that locality.

CDC currently has a variety of GIS health resources available for use by health professionals and the general public, including GATHER, or Geographic Analysis Tool for Health and Environmental Research; CDC Epi Info and Epi Map Software for doing database construction and analysis with epidemiology statistics, maps, and graphs; and the Migrant Clinician’s Network Health and Environment Analysis and Research Tool.

To learn more about GIS and its importance to CDC and public health, visit
Geographic Information Systems (GIS) at CDC
CDC GIS Web Applications