Neighborhood drug markets: a risk environment for bacterial sexually transmitted infections among urban youth.

We hypothesized that neighborhoods with drug markets, as compared to those without, have a greater concentration of infected sex partners, i.e. core transmitters, and that in these areas, there is an increased risk environment for STIs. This study determined if neighborhood drug markets were associated with a high-risk sex partnership and, separately, with a current bacterial STI (chlamydia and/or gonorrhea) after controlling for individual demographic and sexual risk factors among a household sample of young people in Baltimore City, MD. Analyses also tested whether links were independent of neighborhood socioeconomic status. Data for this study were collected from a household study, systematic social observations and police arrest, public health STI surveillance and U.S. census data. Nonlinear multilevel models showed that living in neighborhoods with household survey-reported drug markets increased the likelihood of having a high-risk sex partnership after controlling for individual-level demographic factors and illicit drug use and neighborhood socioeconomic status. Further, living in neighborhoods with survey-reported drug markets increased the likelihood of having a current bacterial STI after controlling for individual-level demographic and sexual risk factors and neighborhood socioeconomic status. The results suggest that local conditions in neighborhoods with drug markets may play an important role in setting-up risk environments for high-risk sex partnerships and bacterial STIs. Patterns observed appeared dependent on the type of drug market indicator used. Future studies should explore how conditions in areas with local drug markets may alter sexual networks structures and whether specific types of drug markets are particularly important in determining STI risk.