CROI 2015 Program and Abstracts

Abstract Listing

Poster Abstracts

1062 Serosorting and Sexual Risk Behavior Influenced by Perceived HIV Serostatus Among MSM Kathleen A. Brady ; Jennifer Shinefeld; Catherine Mezzacappa Philadelphia Department of Public Health, Philadelphia, PA, US

Background: According to the CDC, unknown HIV serostatus and unprotected anal sex among men who have sex with men (MSM) contribute to high levels of new infections in this population. This study used data from the National HIV Behavioral Surveillance System (NHBS) to analyze the relationship between perceived HIV serostatus and high-risk sexual behaviors among MSM. Methods: NHBS is conducted annually in 20 metropolitan areas using a standardized survey and free HIV testing to analyze trends in HIV risk behaviors and prevalence among high risk groups including MSM. HIV testing included a rapid test at time of interview and a confirmatory test. We combined data from the 2008 and 2011 MSM cycles in Philadelphia and performed bivariate analyses of sexual risk behaviors at last sexual encounter across perceived HIV serostatus. Perceived HIV serostatus was defined as ‘known negative’ for a man who had a negative HIV test in the past year, ‘known positive’ for a man who had ever tested positive for HIV, and ‘unknown’ for a man who had not had an HIV test in the past year nor previously tested positive. Serosorting is the practice of choosing a partner known to be of the same HIV serostatus in order to reduce the risk of acquiring or transmitting HIV. Results: Of 1194 respondents, 31.3%were known negative, 5.5% known positive, and 63.2% unknown perceived serostatus. Testing revealed that 3.0% of known negative and 4.4% of unknown perceived serostatus were HIV positive. There were no differences in frequency of insertive anal sex at last encounter across perceived serostatus. Known negative men were less likely to use a condom during receptive anal intercourse (p=0.006). Approximately two-thirds of all respondents knew the HIV status of their most recent partner. Among those who knew their partner’s HIV status, serosorting was extremely prevalent: 73.9% of known positive men had sex with an HIV positive partner, compared to 5.6% of unknown, and 4.4% of known negative men, (p<0.0001).

Poster Abstracts

Conclusions: Knowledge of HIV serostatus influences sexual behaviors among MSM, particularly through serosorting. However, over 60% of men surveyed had not been tested for HIV in the previous year and a third of men did not know the HIV status of their most recent partner. Prevention efforts should be tailored to reach those MSM who remain unaware of their HIV status. 1063 Use of the Seroadaptive Strategies of Sexual Positioning and Serosorting by MSM in Nigeria Cristina M. Rodriguez-Hart 1 ; Hongjie Liu 2 ; Ifeanyi K. Orazulike 3 ; Sam Zorowitz 4 ; Sylvia Adebajo 5 ; Lindsay Hughes 6 ; Stefan Baral 7 ; Merlin L. Robb 6 ;William Blattner 1 ; Manhattan Charurat 1 1 University of Maryland School of Medicine, Baltimore, MD, US; 2 University of Maryland School of Public Health, College Park, MD, US; 3 International Center on Advocacy and Rights to Health, Abuja, Nigeria; 4 Massachusetts General Hospital and Harvard Medical School, Boston, MA, US; 5 Population Council, Abuja, Nigeria; 6 US Military HIV Research Program, Bethesda, MD, US; 7 Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, US Background: Sexual positioning and serosorting are two seroadaptive strategies adopted by some men who have sex with men (MSM) as HIV harm reduction strategies. The current analysis investigated these factors among MSM in Nigeria, where rates of infection are 10 fold higher than in the general population, who participated in the TRUST study. Methods: Using respondent-driven sampling, 392 eligible MSM were interviewed. A subject was considered to be engaged in sexual positioning if an HIV positive MSM who knew his status prior to the study reported only receptive anal sex for the previous 12 months or an HIV negative MSM who knew his status prior to the study reported only insertive anal sex for the previous 12 months. A subject was considered to be engaged in serosorting if he knew his HIV status prior to the study and reported having only sex partners of the same HIV status. Logistic regression with generalized estimating equations was used to analyze factors associated with engagement in positioning or serosorting. Results: Of the 390 participants with HIV testing history and who were tested for HIV at baseline, 21% (85/390) were HIV positive and reported knowing their status, 29% (114/390) were HIV negative and reported knowing their status, 23% (89/390) were HIV positive and reported not knowing their status, and 25% (97/390) were HIV negative and reported not knowing their status. Among HIV positive MSM who knew their HIV status, 21% (18/85) practiced receptive sex only. Among HIV negative MSMwho knew their status, 39% (44/114) practiced insertive sex only. Engagement in sexual positioning was associated with older age (OR=2.15; 95%CI: 1.07-4.32), not being married to a woman (OR=2.94; 95%CI: 1.03-8.33), and communication with partners about HIV status (OR=1.84; 95%CI: 1.01-3.36). The 384 MSMwho reported any sex partner data generated 1565 sex partner dyads. Serosorting took place only among 192 dyads (12%). Engagement in serosorting was associated with communication with partners about HIV status (OR=3.78; 95%CI: 2.12-6.75) and stronger friendship (OR=1.40; 95%CI: 1.11-1.76).

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CROI 2015