1. Nuanced seroadaptive behaviors among Seattle MSM: sexual decision- making based on ART use/viral load and recency of partner HIV testing Christine M. Khosropour, David A. Katz, Julia C. Dombrowski, Matthew R. Golden

2. Background Seroadaptive behaviors: choosing partners, sexual role or condom use based on partner HIV status (e.g., serosorting) Common and increasing in some settings* Some seroadaptive behaviors may protect from HIV *Poster # WEPEC660

3. Background Increasing antiretroviral therapy (ART) use and frequent HIV testing –Seroadaptive behaviors evolving and becoming more complex Anecdotes of nuanced seroadaptive behaviors emerging among MSM

4. Objectives Examine the prevalence and HIV test positivity of 2 behaviors: 1.Condomless anal intercourse (CAI) with HIV- negative partners based on timing of partner’s last HIV test 2.Having sex or using condoms with HIV-positive partners based on partners’ ART use or viral load (VL)

5. Methods: Study Design Cross-sectional study conducted in an STD clinic in Seattle, WA 2014-2015 Men aged >18 years who reported sex with a man in the prior 12 months 5-minute computer-assisted self-interview (CASI) CASI responses linked to HIV test results

6. Methods: CASI Assessment Partner testing recency  Limited to HIV-negative respondents with HIV- negative partners  Behaviors in prior 12 mo  Most recent HIV-negative partner  Topics covered:  Asked partner about timing of partner’s last HIV test  Condom use with partner  Reason for no condom use  Limited to HIV-negative and HIV-positive respondents with HIV- positive partners  Behaviors in prior 12 mo  HIV-positive partners in aggregate  Topics covered:  Asked partner about ART/VL  Choice to have sex/use condoms based on partners’ ART/VL Partner ART use/VL

7. Methods: Statistical Analysis Visit-level analysis Chi-square or Fisher’s exact tests to compare proportions

8. Results Enrolled MSM at 1,791 (57%) of 3,133 visits Characteristic HIV-negative respondent-visits (N = 1,513)* HIV-positive respondent-visits (N = 278)* N (%) Age < 25 years369 (24)22 (8) White, non-Hispanic944 (63)204 (73) >5 anal sex partners, past 12m577 (38)150 (54) CAI with HIV-negative partner1,071 (71)121 (44) CAI with HIV-positive partner274 (18)224 (81) HIV test positivity15 (1.3)-- *1,011 unique HIV-negative respondents 203 unique HIV-positive respondents

9. Behavior 1: Testing Recency 1,300 (86%) Asked partner about timing of last test 1,300 (86%) Asked partner about timing of last test 757 (58%) Partner tested <3 months ago 229 (63%) [30%] Decision not to use condom based on timing of partner’s last test 229 (63%) [30%] Decision not to use condom based on timing of partner’s last test 543 (42%) Partner tested >3 months ago 89 (40%) [16%] Decision not to use condom based on timing of partner’s last test 89 (40%) [16%] Decision not to use condom based on timing of partner’s last test P<.001 361 (48%) Had CAI with partner 221 (41%) Had CAI with partner P=.01 1,513 HIV-negative respondent-visits

10. Behavior 1: Testing Recency 1,300 (86%) Asked partner about timing of last test 1,300 (86%) Asked partner about timing of last test 757 (58%) Partner tested <3 months ago 229 (63%) Decided not to use condom because partner’s last HIV test was recent enough 229 (63%) Decided not to use condom because partner’s last HIV test was recent enough 543 (42%) Partner tested >3 months ago 89 (40%) Decided not to use condom because partner’s last HIV test was recent enough 89 (40%) Decided not to use condom because partner’s last HIV test was recent enough P<.001 361 (48%) Had CAI with partner 221 (41%) Had CAI with partner P=.01 1,513 HIV-negative respondent-visits

11. Behavior 2: ART use/VL N=346 HIV-negative respondent-visits N=226 HIV-positive respondent-visits

12. Behavior 2: ART use/VL P=.004 HIV test positivity by sexual decision-making (N = 227) CAI by sexual decision-making (N = 467) N=2 N=3

13. Limitations ART use/VL questions asked in aggregate; could not ascertain behaviors with specific partners Low HIV-test positivity yielded small numbers for test positivity analysis Generalizability is uncertain

14. Summary Many MSM decide whether or not to use condoms based on partner HIV testing recency or ART use/VL

15. Conclusions HIV testing frequency and ART use impacts sexual behavior decision-making among MSM Effects of nuanced behaviors are uncertain but are potentially protective from HIV Questions utility of measuring CAI exclusive of other partner factors

16. Acknowledgements –Study participants –Public Health – Seattle & King County STD Clinic Staff Funding National Institutes of Health R21 AI098497 National Institutes of Health T32 AI07140