When examining the transmission of HIV, it is important to consider sexual mixing patterns (the difference/similarity in risk of HIV infection between two sexual partners) and seroadaptive practice (when people decide whether to engage sexually with each other based on both partners’ HIV statuses).
Given that both PrEP (a preventative medication for those at high risk for HIV) and sexual mixing patterns influence HIV epidemics among men who have sex with men (MSM), it is necessary to examine how one may affect the other. However, little is known in this area specific to the MSM population in Canada.
Our results could be used to inform and help ensure that PrEP programs are effective – reaching the right people at the right time, and protecting MSM in Canada from HIV infection.
Study 1: Population-level sexual mixing by HIV status and pre-exposure prophylaxis (PrEP) use among MSM in Montréal, Canada: implications for HIV prevention
Using cross-sectional survey data of MSM in Montréal, Canada, we will:
- Quantify population-level serosorting by comparing observed partnership distribution by HIV status to that expected by chance
- Quantify population-level serosorting among HIV-negative MSM stratified by PrEP use
- Quantify population-level PrEP-matching by comparing observed partnership distribution by PrEP use to that expected by chance
Study 2: Modeling PrEP and in the influence of sexual mixing patterns on HIV epidemics among MSM
This sub-project uses a dynamic, compartmental HIV-transmission model among gay, bisexual, and other MSM living in an urban setting in Canada to estimate:
- The influence of baseline serosorting patterns on the potential transmission impact of PrEP
- The influence of PrEP-mediated change in serosorting on the transmission impact of PrEP
- Its sensitivity to epidemiologic and intervention (PrEP effectiveness and coverage) conditions
Study 3: Modeling the cost-effectiveness of PrEP in Toronto
This is a systematic review which evaluates the cost-effectiveness of PrEP in high-income settings.