HIV Seroadaptation Among Individuals, Within Sexual Dyads, and by Sexual Episodes, Men Who Have Sex With Men, San Francisco, 2008

Seroadaptation refers to sexual behavior to reduce the risk of acquiring or transmitting HIV, based on knowing one's own serostatus as well as that of one's partners. In the current study, the team measured the prevalence of seroadaptive behaviors among MSM recruited through time-location sampling across three perspectives: by individuals (n=1,207 MSM), among sexual dyads (n=3,746 partnerships), and for sexual episodes (n=63,789 episodes) in the preceding six months.

When considering the consistent behavioral pattern of individuals, seroadaptation was more common than 100 percent condom use (adopted by 39.1 percent vs. 25.0 percent of men, respectively). Among sexual dyads, 100 percent condom use was more common than seroadaptation (33.1 percent vs. 26.4 percent, respectively).

"Considering episodes of sex, not having anal intercourse (65.0 percent) and condom use (16.0 percent) were the most common risk reduction behaviors," the authors reported. "Sex of highest acquisition and transmission risks (unprotected anal intercourse with a HIV serodiscordant or unknown status partner in the riskier position) occurred in only 1.6 percent of sexual episodes."

The authors concluded, "In aggregate, MSM achieve a high level of sexual harm reduction through multiple strategies. Detailed measures of seroadaptive behaviors are needed to effectively target HIV risk and gauge the potential of serosorting and related sexual harm reduction strategies on the HIV epidemic."