Viral Load Awareness and Risk Behavior in Serodiscordant Couples

1. Viral load awareness and risk behaviour in male serodiscordant couples in Australia, Brazil and Thailand Benjamin R Bavinton, Fengyi Jin, Garrett P Prestage, Iryna Zablotska, Beatriz Grinsztejn, Nittaya Phanuphak, Ruth Khalili Friedman, and Andrew E Grulich for the Opposites Attract Study Group 21 July 2015 8th International AIDS Society Conference on HIV Pathogenesis, Treatment & Prevention Vancouver, Canada

2. Background HIV ‘Treatment as Prevention’: HPTN 052 Total seroconversions Total N = 1,763 couples 39 Linked infections Unlinked infections 28 11 Delayed ART Early ART 96% reduction in HIV transmission risk (HR=0.04, 95%CI=0.01-0.27, p<0.001) 27 1 (Cohen et al., 2011, NEJM)

3. Background HIV ‘Treatment as Prevention’: PARTNER (Rodger et al., 2014, CROI)

4. Background HIV ‘Treatment as Prevention’: Opposites Attract (Grulich et al., 2015, CROI)

5. Background • Sexual risk behaviour in serodiscordant couples: • In most clinical trials, there is no evidence of increased condomless intercourse due to the protection provided by antiretrovirals. • It is a rapidly changing field; new evidence and community education may impact upon sexual behaviour within couples in different settings.

6. Method: Opposites Attract Study Design • Prospective longitudinal cohort study. • Unit of recruitment is a couple comprising two men in an ongoing sexual relationship where one is HIV-positive and the other HIV-negative at baseline. • Couples attend at least 2 clinic visits per year: • Viral load and CD4 in HIV-positive partners • HIV antibody tests in HIV-negative partners • Tests for sexually transmissible infections in both partners. • Both partners complete a questionnaire at each clinic visit. • Phylogenetic analysis conducted for the interim analysis and at the end of the study.

7. Method: Study Sites Bangkok Thai Red Cross AIDS Research Centre Cairns Cairns Sexual Health Centre Rio de Janeiro Instituto de PesquisaClinicaEvandroChagas (IPEC) Brisbane Gladstone Road Medical Centre Sydney Burwood Road Clinic East Sydney Doctors Holdsworth House RPA Sexual Health St Vincent’s Hospital (IBAC) Sydney Sexual Health Centre Taylor Square Private Clinic Melbourne Alfred Hospital Centre Clinic Melbourne Sexual Health Centre Northside Clinic Prahran Market Clinic

8. Research Questions • Do the HIV-negative partners in Opposites Attract report more condomless anal intercourse (CLAI) with their HIV-positive study partner when they perceive their partner to have undetectable viral load? • Are there differences between the three countries participating in Opposites Attract?

9. Results: Couples Enrolled • By 30 June 2015, 269 couples were enrolled.

10. Results: Demographic Characteristics

11. Results: Couple Characteristics • Length of relationship: • 69.1% of couples lived together. • 96.0% described each other as ‘partner’, ‘husband’ or ‘boyfriend’.

12. Results: Sex with Outside Partners • Any sex with outside partners in previous 3 months: OR=0.3, CI=0.2-0.6, p<0.001 p=0.134 • Any condomless anal intercourse with outside partners inprevious 3 months: OR=0.3, CI=0.2-0.6, p<0.001 OR=0.07, CI=0.02-0.3, p=0.007

13. Results: ART and Viral Load • HIV-positive partners taking ART: p=0.226 OR=0.1, CI=0.04-0.2, p<0.001 • HIV-positive partnerswith viral load of less than 200 copiesper mL: p=0.908 OR=0.1, CI=0.1-0.3, p<0.001

14. Results: Perceived Viral Load • Negative partners outside Australia, especially in Thailand, were less likely to know their partner’s last viral load test result.

15. Results: Viral Load Communication • Of the HIV-negative partners who ‘knew’ their HIV-positive partner’s last viral load result: • Partner told: • Australia: 85% • Brazil: 70% • Thailand: 58% • (p<0.001) Respondents could select multiple items

16. Results: Condomless anal intercourse (CLAI) • Overall, 53.2% of HIV-negative partners reported having any CLAI with HIV-positive study partners in the previous 3 months.

17. Results: CLAI and Perceived Viral Load • Overall, HIV-negative partners were more likely to report CLAI with their study partner when the perceived viral load was undetectable. p = 0.316 OR = 2.695%CI = 1.5 − 4.7 p = 0.001 HIV-negative partner’s perception of positive partner’s viral load

18. Results: CLAI and Perceived Viral Load • This association between perceived undetectable viral load and increased CLAI was evident only amongst Australian couples.

19. Interpretations • At the level of the individual, there may be differences in: • Understanding and awareness of viral load (e.g. in Thailand, viral load monitoring is not routinely conducted until ART initiation) • Research literacy • Capacity to determine how to incorporate new scientific findings about viral load and prevention into sexual lives • At the level of clinicians and health care workers, there may be differences in: • Limited dialogue about treatment as prevention, despite guidelines recommending treatment for all • Support for the idea of undetectable viral load as a prevention strategy • Willingness to share treatment as prevention findings openly with patients

20. Interpretations • At the level of the gay community, in Australia there has been widespread discussion of viral load in the context of ‘treatment as prevention’ for several years: • The Swiss Statement (2008) • Community education campaigns targeting HIV-positive men to consider early treatment (2013-2015) • Community education campaigns explicitly on the reduced risk of undetectable viral load targeting all gay men (2013-2015)

21. Title

22. Interpretations • In our sample, Australian men had more optimistic attitudes towards ‘treatment as prevention’. p=0.001 p=0.990 p=0.002 Number of scale items = 5. Scale range = 1 to 5

23. Interpretations • Logistic regression models: • Outcome = Any condomless anal intercourse with study partner in the previous 3 months

24. Conclusion • Condomless anal intercourse is relatively common in these male serodiscordant couples (53%), and was more prevalent in Australia (68%). • HIV-negative partners outside Australia, particularly in Thailand, were less likely to know their study partner’s last viral load result. • There was a strong association between perceived undetectable viral load and increased condomless intercourse in Australia, but not in Brazil or Thailand. • Optimistic beliefs about ‘treatment as prevention’ were related to increased CLAI, and may affect sexual behaviour more than viral load results in Brazil and Thailand.

25. Acknowledgements All Study Participants Study Investigators: Andrew Grulich, Garrett Prestage, Iryna Zablotska, Fengyi Jin, David A Cooper, Anthony Kelleher, David Wilson, Kersten Koelsch, Christopher Fairley, Kathy Triffitt, Sean Emery, Beatriz Grinsztejn, Nittaya Phanuphak Project Leader: Benjamin Bavinton Research Assistant: Lara Cassar Site Investigators: David Baker, Mark Bloch, Nicolas Doong, Jennifer Hoy, Anna McNulty, Richard Moore, David Orth, Catherine Pell, Norm Roth, Darren Russell, Ban Kiem Tee, David Templeton All Recruiting Clinicians Site Coordinators/Staff: Colette Cashman, Jess Costa, Sian Edwards, Ruth Khalili Friedman, Shruti Gupta, Peta Hamill, Shane Hewitt, Julia Hoffman, Piranun Hongchookiat, Vicki Ieroklis, Helen Kent, Helen Lau, Karen McRae, Siriporn Nonenoy, Elizabeth Odgers, Janine Roney, Egydio Sampaio, Nicky Sharp, Julie Silvers, Rachel Woolstencroft, David Youds Laboratory Partners: Kate Merlin, Doris Chibo, Bertha Fsadni, Shayla Sharmin, Brooke Berry, Sandro Nazer, Tippawan Pankam Community Partners: ACON, VAC, Positive Life NSW, Living Positive Victoria, HIV/AIDS Legal Centre Funders: National Health and Medical Research Council; Foundation for AIDS Research (amfAR)