HIV and other sexually transmitted co-infections by sexual identity among men who have sex with men recruited by respondent driven sampling (RDS) in Buenos Aires, Argentina

CARBALLO DIEGUEZ A; PANDO MA; BALAN I; DOLEZAL C; MARONE R; BARREDA V; AVILA MM

Vienna

Congreso; XVIII International AIDS Conference; 2010

IAS

Introduction: RDS, a methodology designed to access hidden populations, has been used for the first time in Argentina to recruit MSM who constitute one of the populations most affected by HIV and other STIs in Argentina. All previous prevalence studies on MSM were based on convenience samples. Methods: MSM were recruited through RDS (respondent driven sampling) for an HIV-prevalence study. Men were 18 years of age or older, residents of Buenos Aires, self-report having sex with men at least 10 times in their lives and at least once in the past six months. Specimens were collected for HIV and STI detection. Results A total of 496 MSM were recruited showing a prevalence of 15.7, 22.9, 7.6, 20.2, 2.5 and 82.9 for HIV, HBV, HCV, T. pallidum (syphilis), Chlamydia and HPV, respectively.  (Chlamydia and HPV tests were only performed for 88 and 109 participants.)  Men were divided in two groups: those who only reported having sex with men (Group 1, n=128) vs. those who also had sex with women and/or transvestites in the past year (group 2, n=368). Group 1 had significantly higher rates of HIV, HBV, syphilis and HPV than group 2 (32% vs. 12%, 38% vs. 17%, 36% vs. 15%, 88% vs. 71%).  Rates of HCV were higher among group 2, but not significantly so (4% vs. 9%).  There were insufficient cases of Chlamydia for a statistical test (n=1).  The groups did not differ on prevalence of injection drug use in the past 2 months (3% vs 6%).  Group 1 was significantly older (mean age 34.9 vs 29.0) and more educated (5.5 vs. 3.9 on a 9-point scale). Conclusions: Remarkably, men who have sex only with other men are more at risk of HIV and other STIs, except for HCV.