Assessing the Impact of the Houston STD Mobile Clinic in Vulnerable Populations through Data Mapping

Background: In response to the 2007 outbreak of syphilis in Houston, Texas, the City of Houston deployed two mobile units to provide testing among vulnerable populations. Research regarding outbreaks has increasingly incorporated a variety of social, behavioral and economic data into traditional mapping.

Purpose: To map the coverage areas of the mobile clinics in relationship to the incidence of syphilis for 2007. The results of this analysis have direct implications for the logistics of mobile clinic use for outbreak response to the syndemic of STDs.

Methods: The incidence of syphilis was mapped using the count of patients per zip code. The sites and the frequency of mobile clinic stops were overlaid to the incidence map to assess the spatial variations. Socio-economic data from the US Census of the zip codes allowed researchers to identify any gaps in mobile clinic service according to disease burden. ArcGIS was used to create the maps.

Results: These maps combine administrative, epidemiological and geographic data in a graphical form. The overlay of data addresses fundamental questions of program effectiveness that include service utilization, intensity and penetration of programs into the targeted population.

Conclusions: This project demonstrates that the utility of GIS mapping technology for intervention/prevention planning. Results also indicate the utility of mobile clinics for outbreak response and targeted outreach to populations for whom mobility, access and/or travel to treatment is a significant barrier. -->