HIV infection and risk factors among men who have sex with men in Zanzibar (Ugunja), Tanzania
Background: HIV prevalence in Zanzibar is <1% in the general population, but no data is available for high risk groups including men who have sex with men (MSM). In 2007, a seroprevalence survey was conducted to investigate HIV, sexually transmitted infections (STI), and related risk factors among MSM in Unguja, Zanzibar.
Methods: Respondent-driven sampling was used to recruit self-identified MSM. Men aged ³ 15 years were eligible if they were living in Unguja and reported engaging in anal sex within the past three months. After providing informed consent, participants were interviewed about their HIV risk behaviours and venous blood was tested for HIV and Hepatitis C (HCV). 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 enrolled in the survey. The mean age was 29.7 years (range 17-70). In the past month, MSM reporting sexual intercourse had a mean of 5.7 partners, 60% reported having a female partner, and 65% reported being paid for sex by a male partner. At last intercourse, more than two-thirds of MSM reported unprotected sex. In the past three months, 14% reported using injection drugs. Only 19% ever had an HIV test. Prevalence of HIV was 12.3% (95%CI=8.7-16.2), and HCV was 14.7% (CI=11.2-18.6). MSM infected with HIV were significantly more likely to have injected drugs in the past three months (UOR 2.1, CI=1.1-5.7) and to have ³2 non-paying receptive male partners in the past month (UOR 2.5, CI=1.2-5.2).
Conclusions: MSM in Zanzibar have high HIV prevalence and engage in risk behaviors including injection drug use, unprotected sex, and transactional sex. MSM have a risk of transmitting HIV into the general population through female partners. Targeted interventions should include STI testing and treatment and HIV counseling and testing with linkages to care and treatment.
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