Socioeconomic gradients in sexually transmitted diseases: A geographic information system-based analysis of poverty, race/ethnicity, and gonorrhea rates in California, 2004-2006

Objectives. We quantified the relationship between gonorrheal infection rates in California and a measure of poverty status and investigated how this relationship and the spatial dispersion of cases varied among the 4 dominant racial/ethnic groups in the state. Methods. We geocoded gonorrhea cases reported in California between 2004 and 2006, and estimated the poverty status of each case by using the percentage of residents living below poverty in the census tract of residence. We calculated infection rates for African American, Asian, Hispanic, and White cases in each of 4 poverty strata. We mapped cases to visualize the patterns of spatial dispersion associated with each race/ethnicity-poverty combination. Results. There was a strong positive relationship between poverty and infection, but racial/ethnic disparities in infection, driven by a disproportionate level of gonorrhea among African Americans, eclipsed this differential. The degree of spatial aggregation varied substantially among groups and was especially pronounced for African Americans with gonorrhea in the highest poverty category. Conclusions. Prevention efforts should target low-income neighborhood "hot spots" to reach the largest numbers of cases, particularly among African Americans.