The role of ‘‘long-term’’ and ‘‘new’’ injectors in a declining HIV/AIDS epidemic in Rio de Janeiro, Brazil

Abstract

Background. A substantial decline of HIV prevalence has been observed in injection drug users (IDUs) from Rio de Janeiro, in recent years. Differential characteristics and behaviors of new (injecting for <6 years) and long-term (>¼6 y) injectors may help to understand recent changes and to implement appropriate prevention strategies. recruited from different communities, interviewed, and tested for HIV. Contingency table analysis and t-tests were used to assess differences between new and long-term injectors. Multiple logistic regression was used to identify independent predictors of HIV serostatus for long-term and new injectors. Results. HIV prevalence was 11.7% for 309 long-term injectors (95% CI 8.1– 15.3) and 4.3% for 300 new injectors (95% CI 2.0–6.6). New injectors reported having engaged in treatment and having received syringes from needle exchange programs (NEPs) more frequently than long-term injectors in the last 6 months, but sharing behaviors remained frequent and even increased vis-a`-vis long-term injectors. For male new injectors, ‘‘sexual intercourse with another man’’ was found to be the sole significant risk factor for HIV infection (Adj OR¼8.03; 95% CI 1.52–42.48). Among male long-term injectors, ‘‘to have ever injected with anyone infected with HIV’’ (Adj OR¼3.91; 95% CI 1.09–14.06) and to have ‘‘ever been in prison’’ (Adj OR¼2.56; 95% CI 1.05–6.24) were found to be significantly associated with HIV infection. Discussion. New injectors are seeking help in drug treatment centers or needle exchange programs. They differ from long-term injectors in terms of their risk factors for HIV infection and have lower prevalence levels for HIV. Such differences may help to understand the recent dynamics of HIV/AIDS in this population and highlight the need to reinforce new injectors’ help-seeking behavior and to reduce current unacceptably high levels of unprotected sex and syringe sharing in new injectors despite attendance of prevention/treatment programs.