Sex Transm Infect 87:162-164 doi:10.1136/sti.2010.042986
  • Behaviour

Seroadaptive behaviours among men who have sex with men in San Francisco: the situation in 2008

  1. Willi McFarland3
  1. 1School of Public Health, University of California, Berkeley, California, USA
  2. 2San Francisco Department of Public Health, San Francisco, California, USA
  3. 3San Francisco Department of Public Health and University of California, San Francisco, California, USA
  1. Correspondence to Dr Willi McFarland, AIDS Office, 25 Van Ness Avenue, Suite 500, San Francisco, CA 94102-6033, USA; willi_mcfarland{at}
  1. Contributors JMS conceived the paper, conducted the primary analyses and wrote the first draft. HFR was principal investigator of the study, had primary oversight for implementation of the study and contributed to the analyses, interpretation and drafts. WM was co-principal investigator of the study, contributed to the design and conceptualisation of the survey and the paper, reviewed analyses and produced the final draft and revisions.

  • Accepted 18 May 2010
  • Published Online First 12 November 2010


Objectives To assess changes in seroadaptive behaviours among men who have sex with men (MSM) in San Francisco over the past 4 years.

Methods 461 MSM were recruited in 2008 as the second wave of the US National HIV Behavioural Surveillance (NHBS) survey in San Francisco. Participants were classified into patterns of seroadaptive behaviours based on reported sexual practices (ie, episodes of insertive and receptive anal sex), condom use, HIV serostatus and partners' serostatus for up to five partners in the preceding 6 months. The prevalence of seroadaptive behaviours was compared with the first wave of NHBS, which used identical methods in 2004.

Results In 2008, 33.7% of HIV-negative and 18.9% of HIV-positive MSM used condoms 100% of the time; nearly half (48.0%) of HIV-negative MSM and two-thirds (66.7%) of HIV-positive MSM had unprotected anal intercourse (UAI). Collectively, seroadaptive behaviours comprised the most common form of risk management; 40.5% of HIV-negative MSM and 51.1% of HIV-positive MSM engaged in some form of seroadaptation, the most common being ‘pure serosorting’ (all UAI with same serostatus partners) reported by 27.5% of HIV-negative MSM and 22.2% of HIV-positive MSM. None of these behaviours were significantly different from their corresponding measures in 2004.

Conclusions Seroadaptation continues to describe the prevailing form of sexual risk management for MSM in San Francisco, suggesting that these behaviours are not novel and require careful measurement to gauge the true potential for the spread of HIV, and nuanced prevention messages to reduce risk.


  • Funding Funding was provided by the Division of HIV/AIDS Prevention, CDC (U62/PS000961). The CDC had no other role in the creation of this paper and the views expressed herein are those of the authors alone. Other Funders: US Centers for Disease Control and Prevention.

  • Competing interests None.

  • Ethics approval This study was conducted with the approval of the Committee on Human Research, University of California, San Francisco.

  • Provenance and peer review Not commissioned; externally peer reviewed.