Seroprevalence and factors associated with herpes simplex virus type 2 among HIV-negative high-risk men who have sex with men from Rio de Janeiro, Brazil: a cross-sectional study

BACKGROUND Herpes simplex virus type 2 (HSV-2) is the leading cause of genital ulcer disease in developing countries, including Brazil, and is especially prevalent among men who have sex with men (MSM). HSV-2 infection represents a risk factor for the acquisition and transmission of other sexually transmitted diseases. The goal of the present cross-sectional study was to estimate HSV-2 seroprevalence and to determine the factors associated with HSV-2 seropositivity in HIV-negative high-risk MSM from Rio de Janeiro, Brazil. METHODS Stored sera were tested to estimate HSV-2 seroprevalence, while socio-demographic and sexual behavior data were used to measure associations between risk factors and HSV-2 seropositivity. Using the Poisson regression model with robust variance, prevalence ratios (PR) were used to estimate de degree of association between risk factors and HSV-2 seropositivity in bivariate and multivariate analyses. RESULTS Seroprevalence of HSV-2 was of 45.7% (184 out of 403). Factors independently associated with HSV-2 seroprevalence in the multivariate model were: older age (>or= 26 years, PR: 1.41 95% Confidence Interval: 1.11-1.78), non-white race (PR: 1.32 95%CI: 1.06-1.64), positive serology for syphilis (PR: 1.65 95%CI: 1.33-2.05), positive serology for hepatitis B (PR: 1.25 95%CI: 0.99-1.57), stable male partner in the past 6 months (PR: 1.42 95%CI: 1.12-1.79), and unprotected anal sex with a stable female partner (PR: 1.46 95%CI: 1.05-2.04) in the 6 months preceding the cross-sectional assessment. CONCLUSION The present study made evident a high prevalence of HSV-2 infection in a sample of HIV-negative high-risk MSM from Rio de Janeiro. This finding indicates the need and urgency for implementing integrated programs for the prevention of HSV-2 and other sexually transmitted diseases, and, in particular, programs targeting high-risk MSM.