Risk Factors Associated with HIV Infection among Male Homosexuals and Bisexuals Followed in an Open Cohort Study: Project Horizonte, Brazil (1994-2010)

<div><p>Background</p><p>There has recently been an increase in HIV infection rates among men who have sex with men (MSM). This study aimed at investigating risk factors associated with incident HIV infection in a MSM cohort–Project Horizonte, Belo Horizonte, Minas Gerais, Brazil.</p><p>Methodology</p><p>This is a nested case-control study in an ongoing open cohort of homosexual and bisexual men, carried out in 1994–2010, during which 1,085 volunteers were enrolled. Each HIV seroconverted volunteer (case) was compared with three randomly selected HIV negative controls, matched by admission date and age (±3 years). During follow-up, 93 volunteers seroconverted and were compared with 279 controls.</p><p>Principal Findings</p><p>The risk factors associated with HIV seroconversion were: contact with partner’s blood during sexual relations (OR 3.7; 95% CI 1.2–11.6), attendance at gay saunas in search for sexual partners (OR 2.6; 95% CI 1.3–5.4), occasional intake of alcohol when flirting and engaging in sexual activity (OR 2.5; 95% CI 1.3–5.1), inconsistent use of condoms in receptive anal sex (OR 2.4; 95% CI 1.1–5.4), little interest to look up information about AIDS (OR 2.6; 95% CI 1.0–6.7) particularly in newspapers (OR 3.4; 95% CI 1.4–8.1).</p><p>Conclusions</p><p>This study shows that MSM are still engaging in risk behavior, such as unprotected anal intercourse, despite taking part in a cohort study on various preventive measures. New preventive strategies in touch with the epidemic’s development and the specificities of this particular population are needed.</p></div

Univariate analysis of sexual behavior, comparing HIV-positive and HIV-negative controls, Project Horizonte, 1994–2010.

(a)<p>OR  =  Matched Odds Ratio.</p><p>Data for refusals, “not done” and “don’t know” are not shown.</p><p>Sexual practices were analyzed independently of the type of partnership (steady or casual).</p><p>Univariate analysis of sexual behavior, comparing HIV-positive and HIV-negative controls, Project Horizonte, 1994–2010.</p

Final conditional logistic regression model: HIV risk factors among MSM, Project Horizonte, 1994–2010.

(a)<p>OR  =  Adjusted Odds Ratio (matched by age and admission time).</p><p>Final conditional logistic regression model: HIV risk factors among MSM, Project Horizonte, 1994–2010.</p

Univariate analysis of the contextual characteristics, comparing HIV-positive and HIV-negative controls, Project Horizonte, 1994–2010.

(a)<p>OR  =  Matched Odds Ratio (matched by age and admission time).</p>(b)<p>Only for those that reported attendance of sex venues.</p><p>Data for “no applicable” and “no response” are not shown.</p><p>Univariate analysis of the contextual characteristics, comparing HIV-positive and HIV-negative controls, Project Horizonte, 1994–2010.</p