Understanding Recent Increases in the Incidence of Sexually Transmitted Infections in Men Having Sex With Men: Changes in Risk Behavior From Risk Avoidance to Risk Reduction

Abstract

In Brief Objective: The objective of this study was to explore risk behavior and routes of transmission in men having sex with men (MSM) with newly diagnosed sexually transmitted infections (STIs). Methods: A questionnaire on clinical diagnosis and manifestation site for acute STIs was completed by physicians participating in a sentinel study. Patients contributed information on sexual risk behavior and the likely route of STI transmission. Results: Three hundred fifty-six diagnosis forms and 169 matching patient questionnaires could be analyzed. The most frequent diagnosis was syphilis (n = 147; 33% primary syphilis with ulcer localization 71% genital, 22% anorectal, and 8% oral; 67% secondary syphilis), followed by gonorrhea (n = 136; 59% genital, 34% rectal, 7% pharyngeal) and Chlamydia trachomatis infection (n = 51; 48% genital, 48% rectal, 4% pharyngeal). In 12 patients, more than one infection was diagnosed, and 2 or 3 sites were affected in 11 patients. Approximately 60% of infections were acquired by genital–oral and oral–anal practices. Unprotected anal intercourse (UAI) was reported more often by HIV-positive men (mostly receptive) and men with high partner numbers. Conclusion: High partner numbers, an important role of genital–oral sexual practices for the transmission of STIs, and relatively high frequencies of mostly receptive UAI in HIV-positive men are all contributing to increasing STI incidences among MSM. Data on sexual risk behavior and routes of sexually transmitted infection transmission in men who have sex with men were collected in the German sexually transmitted disease sentinel surveillance system. Main findings were an important role of genital–oral transmission routes and HIV serostatus-dependent differences in risk-taking behavior.