HIV risk factors and injection drug use among men who have sex with men in Zanzibar (Unguja), Tanzania
Background: In 2007 an HIV seroprevalence survey was conducted in Unguja, Zanzibar and found HIV prevalence among men who have sex with men (MSM) was 12.3% and that HIV infection is associated with injection drug use. Further analysis was conducted to explore this association.
Methods: Respondent-driven sampling was used to recruit self-identified MSM. Men aged > 15 years were eligible if they were living in Unguja and reported engaging in anal sex within 3 months before the survey. After providing informed consent, participants were interviewed about their HIV risk behaviours and venous blood was tested for HIV. Analysis was done using RDSAT 5.6 and unadjusted odds ratios (UOR) and 95% confidence intervals (CI) were calculated.
Results: From April to June, 509 MSM were enrolled in the survey of whom 14% (n=66) reported injection drug use in the past 3 months. Among MSM injection drug users (IDU), 66% used heroin the last time they injected and 51% reported injecting with a used needle. As compared to non-IDU MSM, MSM IDU were significantly more likely to be 25 years or older (UOR=3.4, 95% CI=1.6-8.5); have two or more non-paying male receptive (UOR=1.2, CI=1.0-1.4) or insertive (UOR=1.3, CI=1.1-1.5) sex partners in the past month; and had higher HIV prevalence (24.7% vs. 10%, UOR=2.98, CI=1.4-6.5). Among MSM who had a female partner in the past month (60%), MSM IDU were significantly less likely to report condom use with their last female partner (UOR=0.22, CI=0.08-0.65).
Conclusions: MSM who use injection drugs in Zanzibar have high HIV prevalence and engage in both high risk drug use and sexual practices. MSM IDU potentially serve as a bridge for transmission to the general population. Targeted HIV interventions for MSM IDU must account for the overlap of high-risk sexual and drug-using networks and include linkages to IDU services.
A. Holman1, M. Dahoma2, L. Johnston3, K. Sabin4, A. Othman2, R. Martin5, A. Kim4, M. Mussa2, C. Kendall6, T. Kibuka5, L. Nganga5
1Association of Schools of Public Health/Centers for Disease Control - Tanzania, Strategic Information, Dar es Salaam, Tanzania, United Republic of, 2Zanzibar AIDS Control Program, Ministry of Health and Social Welfare, Stonetown, Tanzania, United Republic of, 3Tulane University School of Public Health and Tropical Medicine, New Orleans, United States, 4HHS-Centers for Disease Control and Prevention, Global AIDS Program, Atlanta, United States, 5HHS-Centers for Disease Control and Prevention, Global AIDS Program, Dar es Salaam, Tanzania, United Republic of, 6Tulane University School of Public Health and Tropical Medicine, Department of International Health & Development, New Orleans, United States