Increases in Unprotected Anal Intercourse with Serodiscordant Casual Partners Among HIV-Negative Gay Men in Sydney

Prevalence of unprotected anal intercourse between casual male partners (UAIC) has been increasing worldwide. We explored trends in serodiscordant UAIC and the associated factors among gay men in Sydney. Proportions of HIV-positive and negative men with serodiscordant casual partners increased during 2003–2006. Prevalence of serodiscordant UAIC increased among HIV-negative men. Age, number of partners, seeking partners online, drug use and esoteric practices were associated with serodiscordant UAIC. Increases in serodiscordant UAIC may be related to growing disclosure. These findings do not indicate a core group of high-risk men. More research is needed about the context in which serodiscordant UAIC happens. Contributors: Iryna B. Zablotska and June Crawford contributed to formulating the research issue and design of this analysis, assumed principal responsibility for data collection, analysis and preparation of the paper. John Imrie, Garrett Prestage, Fengyi Jin, Andrew Grulich and Susan Kippax contributed to this paper at different stages of study design, data collection and analysis, and assisted with the interpretation of the results and the preparation of the paper. All authors have seen and approved the final version of this paper.