High-risk sexual and drug using behaviors among male injection drug users who have sex with men in 2 Mexico-US border cities.

Objectives: The population of Latino men who have sex with men (MSM) and who are also injection drug users (IDUs) is understudied. We explored risk behaviors of MSM/IDUs compared with other male IDUs in 2 Mexican border cities.

Study Design: In 2005, IDUs who had injected within the previous 30 days were recruited using respondent-driven sampling (RDS) in Tijuana and Ciudad Juárez. They underwent antibody testing for HIV, HCV, and syphilis and interviewer-administered surveys. Men were categorized as MSM if they reported > or =1 lifetime male partners. Logistic regression was used to compare MSM/IDUs with non-MSM/IDUs.

Results: A third (31%) of 377 male IDUs were categorized as MSM (47% in Tijuana and 13% in Ciudad Juárez, P <0.01). Combined RDS-adjusted prevalence of HIV and Hepatitis C was 3% (95% CI: 1, 5) and 96%, (95% CI: 94, 99) respectively, while 17% (95% CI: 2, 36) of MSM and 8% (95% CI: 3, 12) of non-MSM tested positive for syphilis antibody. In multivariate logistic regression adjusted for site, MSM/IDUs were more likely than non-MSM/IDUs to have ever used inhalants (OR: 3.4; 95% CI: 1.8, 6.2) or oral tranquilizers (OR: 2.4; 95% CI: 1.3, 4.6), received treatment for a drug problem (OR:1.9; 95% CI: 1.1, 3.2) shared needles in the last six months (OR: 2.1; 95% CI: 1.0, 4.2) and also had higher numbers of lifetime female partners (log-transformed continuous variable, OR: 1.6; 95% CI: 1.2, 2.1).

Conclusions: In these Mexican cities, the proportion of MSM among male IDUs was high. Compared with other male IDUs, MSM/IDUs were more likely to engage in behaviors placing them at risk of acquiring HIV/STIs. Culturally appropriate interventions targeting Latino MSM/IDUs are warranted.