Population-Level Sexual Mixing According to HIV Status and Preexposure Prophylaxis Use Among Men Who Have Sex With Men in Montreal, Canada: Implications for HIV Prevention
Date
2019
Authors
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.
Journal Title
Journal ISSN
Volume Title
Publisher
American Journal of Epidemiology
Abstract
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.
Description
The authors thank the Engage-Montreal office staff and
community engagement committee members, as well as
their community partner agencies.
Keywords
HIV, MSM, PrEP, PrEP-matching, serosorting, sexual mixing patterns
Citation
Wang, L., Moqueet, N., Lambert, G., Grace, D., Rodrigues, R., Cox, J., Lachowsky, N. J., Noor, S. W., Armstrong, H. L., Tan, D. H. S., Burchell, A. N., Ma, H., Apelian, H., Knight, J., Messier-Peet, M., Jollimore, J., Baral, S., Hart, T. A., Moore, D. M., & Mishra, S. (2019). “Population-Level Sexual Mixing According to HIV Status and Preexposure Prophylaxis Use Among Men Who Have Sex With Men in Montreal, Canada: Implications for HIV Prevention.” American Journal of Epidemiology, 189(1), 44-54. DOI: https://doi.org/10.1093/aje/kwz231