Uso de substâncias, situações de risco e soroprevalência em indivíduos que buscam testagem gratuita para HIV em Porto Alegre, Brasil

Objective. To describe substance use, HIV seroprevalence, and risk of exposure to HIV infection in individuals seeking HIV testing in two screening centers (a municipal one and a state one) in the city of Porto Alegre, Rio Grande do Sul, Brazil. Methods. Using a cross-sectional design, we enrolled a convenience sample of 1 026 men and women between 15 and 60 years of age. We included all the subjects who, after an initial triage, reported any drug use or any behavior or situation with risk of HIV transmission. A Brazilian-Portuguese version of the Risk Assessment Battery was used to assess exposure to risk situations. Blood samples were tested for anti-HIV antibodies, using enzyme-linked immunosorbent assay. Before the blood test, individuals participated in a group counseling session (with a maximum of 20 participants) on HIV and AIDS, in line with the criteria of the Ministry of Health of Brazil. Results. Among the sample, a high overall HIV seroprevalence was found, 15.1%. Drug use did not explain all of the risk exposure. In comparison to those who reported no injecting drug use, the odds ratio (OR) for being HIV-positive for those who reported injecting drug use at some point in their life was 7.6 (95% confidence interval (CI) = 4.4 to 13.0). However, only 10.3% of the sample reported any injecting drug use. The variables that were associated with HIV seropositivity were: male gender (OR = 1.8; 95% CI = 1.1 to 2.8), monthly family income below three times the minimum-salary amount (OR = 2.1; 95% CI = 1.3 to 3.5), age over 25 (OR = 1.7; 95% CI = 1.1 to 2.7), and having had sexual relations with a partner who was possibly HIV-positive (OR = 1.8; 95% CI = 1.1 to 3.2). Conclusions. Even irregular or occasional drug use increases the odds of seropositivity, particularly if intravenous drugs are used. Sexual transmission played an important role in seropositivity in this sample, indicating that drug use can affect the judgment of risk and thus contribute to HIV transmission.