Serosorting and sexual risk behaviour according to different casual partnership types among MSM: the study of one-night stands and sex buddies

Abstract

Among HIV-negative men who have sex with men (MSM), any incident of unprotected anal intercourse (UAI) between casual partners is usually regarded as risky for HIV transmission. However, men are increasingly using knowledge of their casual partner's HIV-status to reduce HIV risk during UAI (i.e., serosorting). Since familiarity between casual partners may lead to higher levels of UAI and serosorting, we examined how often men have UAI and practice serosorting with three types of casual partnerships that differ in their degree of familiarity.

We included 240 HIV-negative men of the Amsterdam Cohort Study among MSM. We distinguished three types of casual partnerships: one-night stand (“met by chance and had sex only once”); multiple-time casual partner (“met and had sex with several times”) and the “regular” casual partner (“sex buddy”). Serosorting was defined as UAI with an HIV-concordant partner. Generalised estimating equations analyses were used to examine the association between type of casual partnership and sexual risk behaviour.

Analyses revealed that men with a sex buddy were more likely to have UAI than men with a one-night stand (OR [95%CI] 2.39 [1.39–4.09]). However, men with a sex buddy were also more likely to practice serosorting than men with a one-night stand (OR [95%CI] 5.20 [1.20–22.52]).

Men with a sex buddy had more UAI but also reported more serosorting than men with a one-night stand. As a result, the proportion of UAI without serosorting is lower for men with a sex buddy, and therefore men might have less UAI at risk for HIV with this partner type. However, the protective value of serosorting with a sex buddy against HIV transmission needs to be further established. At this time, we suggest that a distinction between the one-night stand and the sex buddy should be incorporated in future studies as men behave significantly different with the two partner types.

Keywords:

• men who have sex with men
• serosorting
• sexual behaviour
• risk reduction behaviour
• types of casual partnerships
• unprotected anal intercourse

Acknowledgements

The authors would like to thank the research nurses Marc van Wijk and Marjolein Martens for their contribution in data collection; Bart Maertzdorf and Anneke Krol for the cohort data management; Martijn van Rooijen for helping out with the statistical analyses; Ronald Geskus for critically reviewing the statistical analyses and the manuscript; Roel Coutinho for critically reviewing the manuscript; and Susan T. Landry for the English review. Furthermore, we express our gratitude to all the participants who made this study possible.

Sponsorship: The Amsterdam Cohort Studies on HIV infection and AIDS, a collaboration between the Public Health Service of Amsterdam, the Academic Medical Center of the University of Amsterdam, Sanquin Blood Supply Foundation and the University Medical Center Utrecht, are part of the Netherlands HIV Monitoring Foundation and financially supported by the Netherlands National Institute for Public Health and the Environment (RIVM). Additional funding for the present study was given by the AIDS Fonds (project number 2008025).