title: HIV risk and the overlap of injecting drug use and high-risk sexual behaviours among men who have sex with men in Zanzibar (Unguja), Tanzania.
abstract: BACKGROUND
  Men who have sex with men and inject drugs (MSM-IDU) are particularly vulnerable to HIV infection and have the potential to transmit HIV across multiple populations through their male and female sexual partners and injection drug-using partners.
  
  
  METHODS
  Respondent-driven sampling was used to recruit men who reported engaging in anal sex with another man in the past 3 months, aged ≥15 years, and living in Unguja, Zanzibar. Participants responded to a face-to-face interview about their HIV and injecting risk behaviours and were tested for HIV, Hepatitis B (HBV) and C (HCV) and syphilis.
  
  
  RESULTS
  Among the 509 MSM who enrolled in the survey, 14% (n=66) reported injecting drugs in the past 3 months among which 66% used heroin, 60% used a needle after someone else had and 68% passed a needle to someone else after using it. MSM-IDU were significantly more likely to have two or more non-paying male receptive sex partners and to have engaged in group sex in the past month, to have symptoms of a sexually transmitted infection in past 6 months, to have been arrested or beaten in the past 12 months and to be infected with HIV and co-infected with HIV and HCV compared to MSM who did not inject drugs. MSM-IDU were less likely to have used a condom at last sex with a non-paid female partner, to know where to get a confidential HIV test and to have ever been tested for HIV compared to MSM who did not inject drugs.
  
  
  CONCLUSIONS
  MSM-IDU, and MSM in general, in Unguja practice multiple high-risk behaviours that put them at risk for blood-borne and sexual transmission of HIV and HCV infection. Targeted interventions for MSM-IDU must account for the overlap of high-risk sexual and drug-using networks and integrate injection drug use and HIV services.
authors.affiliation: Tulane University, School of Public Health & Tropical Medicine, Department of International Health & Development, Center for Global Health Equity, New Orleans, LA, USA. lsjohnston.global@gmail.com
authors.forename: Lisa G
authors.initials: LG
authors.lastname: Johnston
authors.forename: Abigail
authors.initials: A
authors.lastname: Holman
authors.forename: Mohammed
authors.initials: M
authors.lastname: Dahoma
authors.forename: Leigh Ann
authors.initials: LA
authors.lastname: Miller
authors.forename: Evelyn
authors.initials: E
authors.lastname: Kim
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Mussa
authors.forename: Asha A
authors.initials: AA
authors.lastname: Othman
authors.forename: Andrea
authors.initials: A
authors.lastname: Kim
authors.forename: Carl
authors.initials: C
authors.lastname: Kendall
authors.forename: Keith
authors.initials: K
authors.lastname: Sabin
mesh_terms: D000328:Adult; D017280:Condoms / Q000706:statistics & numerical data; D003430:Cross-Sectional Studies; D003625:Data Collection; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000635:transmission; D006526:Hepatitis C / Q000453:epidemiology / Q000635:transmission; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D016485:Needle Sharing / Q000706:statistics & numerical data; D012309:Risk-Taking; D012725:Sexual Behavior / Q000706:statistics & numerical data; D012747:Sexual Partners; D015819:Substance Abuse, Intravenous / Q000150:complications* / Q000453:epidemiology; D013636:Tanzania / Q000453:epidemiology; D055815:Young Adult