HIV and STI knowledge, testing, and risk among adult crack users in Mexico city: baseline findings from a feasibility study.

Recent research has documented crack cocaine's increasing spread in Mexico, which is likely to contribute to the rapid transmission of HIV and other sexually transmitted infections (STIs). In Mexico, crack use is increasing most rapidly in vulnerable, hard-to-reach populations, where little is known about risk behaviors. This report aims to present baseline data regarding HIV and STI knowledge and testing prevalence from an innovative projection mapping HIV intervention, in which 3-D illusions, animation, and visual text graphics and sound are projected onto buildings with health messages that were designed to disrupt everyday life and connect with the target population. Fifty-eight men and women who used crack in the past month without receiving drug treatment were recruited and interviewed before the projection mapping intervention took place. Testing instruments included a sociodemographic assessment, drug use and treatment profile, HIV and STI knowledge questionnaires, and a sex and drug risk assessment. The mean scores for respondents on the HIV Knowledge Questionnaire (10.5 out of 18, 58.3%) and STD Knowledge Questionnaire (9.5 out of 27, 35.2%) were both low. Respondents also reported high rates of sexual risk behaviors, with 73% reporting never using a condom and 64% never being tested for HIV. This report provides a portrait of STI and HIV risk among a vulnerable population in Mexico City and the need for urgent interventions to prevent the spread of STIs and HIV. The associated projection mapping intervention will seek to increase HIV and STI knowledge and reduce risk in this hard-to-reach population.