Department of Epidemiology and Biostatistics, School of Population and Global Health, McGill University, Montréal, Québec, Canada.
Direction Régionale de Santé Publique de Montréal, Montréal, Québec, Canada.
J Int AIDS Soc. 2023 Dec;26(12):e26194. doi: 10.1002/jia2.26194.
HIV pre-exposure prophylaxis (PrEP) has been recommended and partly subsidized in Québec, Canada, since 2013. We evaluated the population-level impact of PrEP on HIV transmission among men who have sex with men (MSM) in Montréal, Québec's largest city, over 2013-2021.
We used an agent-based mathematical model of sexual HIV transmission to estimate the fraction of HIV acquisitions averted by PrEP compared to a counterfactual scenario without PrEP. The model was calibrated to local MSM survey, surveillance, and cohort data and accounted for COVID-19 pandemic impacts on sexual activity, HIV prevention, and care. PrEP was modelled from 2013 onwards, assuming 86% individual-level effectiveness. The PrEP eligibility criteria were: any anal sex unprotected by condoms (past 6 months) and either multiple partnerships (past 6 months) or multiple uses of post-exposure prophylaxis (lifetime). To assess potential optimization strategies, we modelled hypothetical scenarios prioritizing PrEP to MSM with high sexual activity (≥11 anal sex partners annually) or aged ⩽45 years, increasing coverage to levels achieved in Vancouver, Canada (where PrEP is free-of-charge), and improving retention.
Over 2013-2021, the estimated annual HIV incidence decreased from 0.4 (90% credible interval [CrI]: 0.3-0.6) to 0.2 (90% CrI: 0.1-0.2) per 100 person-years. PrEP coverage among HIV-negative MSM remained low until 2015 (<1%). Afterwards, coverage increased to a maximum of 10% of all HIV-negative MSM, or about 16% of the 62% PrEP-eligible HIV-negative MSM in 2020. Over 2015-2021, PrEP averted an estimated 20% (90% CrI: 11%-30%) of cumulative HIV acquisitions. The hypothetical scenarios modelled showed that, at the same coverage level, prioritizing PrEP to high sexual activity MSM could have averted 30% (90% CrI: 19%-42%) of HIV acquisitions from 2015-2021. Even larger impacts could have resulted from higher coverage. Under the provincial eligibility criteria, reaching 10% coverage among HIV-negative MSM in 2015 and 30% in 2019, like attained in Vancouver, could have averted up to 63% (90% CrI: 54%-70%) of HIV acquisitions from 2015 to 2021.
PrEP reduced population-level HIV transmission among Montréal MSM. However, our study suggests missed prevention opportunities and adds support for public policies that reduce PrEP barriers, financial or otherwise, to MSM at risk of HIV acquisition.
自 2013 年以来，加拿大魁北克省已推荐并部分资助艾滋病毒暴露前预防（PrEP）。我们评估了 2013 年至 2021 年期间，在魁北克省最大城市蒙特利尔，PrEP 对男男性行为者（MSM）中 HIV 传播的人群水平影响。
我们使用性 HIV 传播的基于代理的数学模型来估计 PrEP 与没有 PrEP 的情况下相比，避免的 HIV 感染人数。该模型根据当地 MSM 调查、监测和队列数据进行了校准，并考虑了 COVID-19 大流行对性活动、HIV 预防和护理的影响。从 2013 年开始对 PrEP 进行建模，假设个体层面的有效性为 86%。PrEP 的资格标准是：过去 6 个月内任何未使用安全套的肛交（过去 6 个月），或者过去 6 个月内有多个性伴侣或多次使用接触后预防（终生）。为了评估潜在的优化策略，我们对 MSM 中高性行为（每年≥11 个性伴侣）或年龄 ⩽45 岁的 MSM 优先使用 PrEP、将覆盖范围提高到加拿大温哥华（在那里 PrEP 是免费的）实现的水平，以及提高保留率等假设情景进行了建模。
2013 年至 2021 年间，估计每年 HIV 发病率从 0.4（90%可信区间 [CrI]：0.3-0.6）下降到 0.2（90% CrI：0.1-0.2）/100 人年。艾滋病毒阴性 MSM 中的 PrEP 覆盖率直到 2015 年（<1%）仍保持较低水平。此后，覆盖率增加到所有 HIV 阴性 MSM 的最高 10%，或 2020 年 62% PrEP 合格的 HIV 阴性 MSM 的 16%。2015 年至 2021 年期间，PrEP 估计避免了 20%（90% CrI：11%-30%）的累积 HIV 感染。所模拟的假设情景表明，在相同的覆盖率下，优先为高性行为 MSM 提供 PrEP 可能会避免 2015 年至 2021 年期间 30%（90% CrI：19%-42%）的 HIV 感染。更高的覆盖率可能会产生更大的影响。根据省级资格标准，在 2015 年和 2019 年，艾滋病毒阴性 MSM 中的覆盖率达到 10%和 30%，与温哥华的情况一样，可能会避免 2015 年至 2021 年期间高达 63%（90% CrI：54%-70%）的 HIV 感染。
PrEP 降低了蒙特利尔 MSM 人群中的 HIV 传播水平。然而，我们的研究表明存在预防机会的错失，并支持减少艾滋病毒感染风险的 MSM 的公共政策，无论这些政策是减少 PrEP 障碍还是减少其他障碍。
