Population-Level Sexual Mixing According to HIV Status and Pre-exposure Prophylaxis Use Among Men Who Have Sex With Men in Montreal, Canada: Implications for HIV Prevention

Wang, Linwei; Moqueet, Nasheed; Lambert, Gilles; Grace, Daniel; Rodrigues, Ricky; Cox, Joseph; Lachowsky, Nathan J.; Noor, Syed W.; Armstrong, Heather L.; Tan, Darrell H. S.; Burchell, Ann N.; Ma, Huiting; Apelian, Herak; Knight, Jesse; Messier-Peet, Marc; Jollimore, Jody; Baral, Stefan; Hart, Trevor; Moore, David M; Mishra, Sharmistha

doi:10.32920/25438465.v1

Population-Level Sexual Mixing According to HIV Status and Pre-exposure Prophylaxis Use Among Men Who Have Sex With Men in Montreal, Canada: Implications for HIV Prevention

journal contribution

posted on 2024-04-04, 20:23 authored by Linwei Wang, Nasheed Moqueet, Gilles Lambert, Daniel Grace, Ricky Rodrigues, Joseph Cox, Nathan J. Lachowsky, Syed W. Noor, Heather L. Armstrong, Darrell H. S. Tan, Ann N. Burchell, Huiting Ma, Herak Apelian, Jesse Knight, Marc Messier-Peet, Jody Jollimore, Stefan Baral, Trevor HartTrevor Hart, David M Moore, Sharmistha Mishra

Using cross-sectional survey data (Engage, 2017-2018) from 1,137 men who have sex with men, ≥16 years old, in Montreal, we compared observed human immunodeficiency virus (HIV) seroconcordance in previous-6-months' sexual partnerships with what would have been observed by chance if zero individuals serosorted. Of 5 recent partnerships where both individuals were HIV-negative, we compared observed concordance in preexposure prophylaxis (PrEP) use with the counterfactual if zero individuals selected partners based on PrEP use. We estimated the concordance by chance using a balancing-partnerships approach assuming proportionate mixing. HIV-positive respondents had a higher proportion of HIV-positive partners (66.4%, 95% confidence interval (CI): 64.0, 68.6) than by chance (23.9%, 95% CI: 23.1, 24.7). HIV-negative respondents (both on and not on PrEP) had higher proportions of HIV-negative partners (82.9% (95% CI: 81.1, 84.7) and 90.7% (95% CI: 89.6, 91.7), respectively) compared with by chance (76.1%, 95% CI: 75.3, 76.9); however, those on PrEP had a higher proportion of HIV-positive partners than those not on PrEP (17.1% (95% CI: 15.3, 18.9) vs. 9.3% (95% CI: 8.3, 10.4). Those on PrEP also had a higher proportion of partners on PrEP among their HIV-negative partners (50.6%, 95% CI: 42.5, 58.8) than by chance (28.5%, 95% CI: 27.5, 29.4). The relationship between PrEP and sexual-mixing patterns demonstrated by less population-level serosorting among those on PrEP and PrEP-matching warrants consideration during PrEP roll-out.