Risk factors for Kaposi's sarcoma-associated herpesvirus (KSHV) infection among homosexual men at high risk for HIV infection in Brazil.

摘要

Background. Kaposi's sarcoma-associated herpesvirus (KSHV) epidemiology has not been fully studied in Brazil. This study evaluated the KSHV epidemiology in a well-characterized cohort of homosexual men in Rio de Janeiro, Brazil. This study compared the performance of two available serologic assays for diagnosis of KSHV infection: Lytic BCBL-1 induced IFA and ELISA K8.1.; Results. Of 927 samples that were analyzed, 681 (73.5%) were positive by lytic IFA, 130 (14.0%) were positive for ELISA, and 125 (13.5%) and 207 (22.3%) were positive and negative, respectively, for both assays. In the univariate analysis age, age of first sex with men, monthly family income, sex for money, sex after drugs, unprotected oral sex with casual partners, use of lubricants during anal sex, HIV infection, serologic evidence of previous syphilis, and hepatitis B infection were significantly associated with KSHV infection. In the logistic regression analysis, age > 35 years (OR 2.7, 95% CI 1.3–5.7), less than 8 years of education (OR 3.1, 95% CI 1.4–6.8), sex at first encounter (OR 2. 1, 95% CI 1.0–4.1), anal sex with stable partner (OR 1.9, 95% 0.9–3.8), HIV infection (OR 5.3, 95% CI 2.1–13.4) and hepatitis B infection (OR 2.5, 95% CI 1.3–5.1) were associated with KSHV infection. Only 5 (0.5%) of the individuals tested were Lytic−ELISA+. When the 547 Lytic+ELISA− individuals were compared to Lytic−ELISA− subjects, the odds ratios tended to move toward the unity for the majority of variables that were studied, including HIV infection and hepatitis B Infection. The sensitivity analysis showed similar results, namely odds ratios tending to unity.; Conclusions. Kaposi's sarcoma-associated herpesvirus (KSHV) infection among homosexual men in Rio de Janeiro, Brazil, similar to developed countries, appears to be transmitted sexually. Lytic BCBL 1-induced immunofluorescence assay (IFA) is less specific than the K8.1 ELISA for diagnosis of KSHV infection among homosexual men without Kaposi's sarcoma. (Abstract shortened by UMI.)