BACKGROUND:
Houston's immunization coverage levels have consistently been lower than both the national and statewide levels for the last decade. Using geographic information systems (GIS) and epidemiologic methods, this project began in an effort to improve coverage in the Houston area through strategic planning of targeted outreach and resource use by identifying areas most in need of services.

OBJECTIVE:
The objectives of this project are to geographically represent immunization and resource data, to compare immunization resources to need, and to identify areas of greatest need for services and outreach.

METHOD:
After compiling data about immunization services, providers, health resources, and vaccine-preventable diseases from a variety of sources, a collection of maps was created and traditional statistics calculated. The map collection allows the visual representation of appropriate data for many epidemiologic and planning questions. The combination of the maps and traditional statistics can then be used for assessing a more accurate picture of Houston's immunization needs and determining appropriate resource allocation and targeted outreach efforts.

RESULT:
Preliminary results reflect an apparent relationship between the areas with the greatest density of children 0-2 years old and the locations of VFC providers with less than 70% coverage levels. A similar relationship appears to exist between the areas where children in kindergarten live and VFC providers as well as other health resources are located. It is unclear if a potential relationship exists between areas with a high density of children, the location of VFC providers with lower coverage levels, and reported cases of vaccine-preventable diseases using visual comparison alone. Further examination of all these relationships is needed.

CONCLUSION:
GIS combined with epidemiologic methods has been a useful tool for needs assessment and planning services.

LEARNING OBJECTIVES:
To demonstrate the usefulness of geographic information systems (GIS, mapping) as a tool for immunization planning and surveillance.