BACKGROUND:
Geographic information system (GIS) software was used to map immunization-related data sets in order to assess the availability of services provided. Current databases held by the County Health and Human Services Agency were used to create these maps.

OBJECTIVE:
Demonstrate the effectiveness of GIS mapping software in:
1. Identifying gaps in availability of flu shot clinics.
2. Identifying and assessing patterns of pertussis outbreaks.
3. Assessing areas of lower immunization rates by providers.

METHOD:
Data from existing databases was geocoded by street address. Flu shot clinic sites for the year 2002-03 were mapped for San Diego County by type and from a list of clinic sites. Reported pertussis cases in 2002 for San Diego County were geocoded from case reports. To assess regional immunization rates, provider location and characteristics for regions throughout the county.

RESULT:
The map of flu shot clinics showed areas that had an abundant number of clinics and other areas that needed additional flu shot clinics the following year. The map of Pertussis cases allowed us to identify areas in the county that suffered from an outbreak of cases and to see where outbreaks were concentrated. The map of providers showed us which areas in the county were reporting low immunization rates.

CONCLUSION:
The generated maps were used to assess areas lacking in adequate services. This information helps the program meet the needs of the community. The maps also allow us to see if and where measures should be taken to improve the services provided and to increase immunization rates.

LEARNING OBJECTIVES:
Describe how geographic patterns for outbreaks and services can be used to guide intervention activities.