Background Identifying predictors that contribute to geographical disparities in sexually transmitted infections (STIs) is necessary. This study assesses the spatial relationship between condom availability to locations of STIs in order to better understand these geographical disparities.

Objectives We conducted a condom availability audit among potential condom-selling establishments. New gonorrhoea and chlamydia cases in 2011 (n=6034) and HIV infection cases from 2006 to 2011 (n=565) were collected by census tract in St Louis, Missouri. 829 potential condom-selling establishments participated in the condom availability audit in St Louis City; 242 of which sold condoms.

Results A negative linear relationship exists between condom vendors and cases of gonorrhoea and chlamydia, after adjusting for concentrated disadvantage and free condom locations. Higher concentrated disadvantage, higher proportions of convenience vendors and free locations were associated with higher rates of HIV.

Conclusions This study was conducted to provide evidence that lack of condom availability is associated with STI rates, and likely is an integral component to influencing the subjective norms surrounding condom use and STI rates. Condom distribution interventions may be addressing availability needs and social norms, yet are more likely to be effective when placed in locations with the highest STI rates.