Problem statement. An in-depth understanding of risk behavior among the esquineros (street corner men), a population of heterosexually identified men in low-income barrios (neighborhoods) of urban and peri-urban, coastal Peru who report frequent sex with men and HIV/STI risk will help to evaluate an HIV prevention intervention conducted with this population.

Methods. We used data from a cohort of esquineros included in the National Institutes of Mental Health (NIMH) Collaborative HIV/STI Prevention Trial in three analyses. First, we used information on risk behaviors among the esquineros to classify these men into groups with different risk patterns. Then data from the trial was used to evaluate the effectiveness of the CPOL intervention among the esquineros specifically exploring the behavioral outcome of reporting unprotected sex with a non-primary partner in the past 3 months. Finally, we used data from the three study visits to characterize the sexual risk behavior of esquineros with other men and to explore the relationship between this behavior and HIV/STI incidence.

Results. Four distinct patterns of risk behavior within the esquinero population emerged. The patterns of risk behavior differed significantly in reports of unprotected sex. The NIMH CPOL intervention was not effective in reducing sexual risk behavior, unprotected sex with a non-primary partner, among the esquineros, which reduced in both intervention and control arms of the trial by 10%. Overall, almost 19% of these men reported sex with a man over the two years of follow-up. Reporting sex with a man was significantly associated with incident HIV/STI infection and this association remains after adjusting for socio-demographic and other sexual risk behaviors.

Conclusions. The esquineros are a high-risk population that needs effective HIV/STI prevention interventions and the only intervention implemented with them to date was not effective. Distinct patterns of risk behavior exist within this population and future interventions may benefit from creating messages relevant to these patterns. The esquineros who report sex with men are at particular risk for HIV/STI infection and should be addressed in prevention interventions. Further research is needed to design effective interventions with this population.