Department of Epidemiology, Johns Hopkins School of Public Health, 615 N Wolfe St, Baltimore, MD, 21205, USA.
Centre for Urban Health Solutions, Li Ka Shing Knowledge Institute, St. Michael's Hospital, University of Toronto, Toronto, Canada.
BMC Infect Dis. 2022 Sep 26;22(1):751. doi: 10.1186/s12879-022-07738-z.
Men who have sex with men (MSM) are consistently burdened by HIV at higher levels than other adults. While HIV prevention programs for MSM are growing in coverage and quality, HIV incidence remains high. In response, pre-exposure prophylaxis (PrEP) was introduced in 2019 to support HIV risk reduction among MSM in Cameroon. Understanding how PrEP initiation programs will change the HIV prevalence among MSM in Cameroon is important to developing effective programs.
This study uses a mathematical model to simulate population-level HIV transmission among MSM in the cities of Yaoundé and Douala, Cameroon. PrEP is incorporated into the model at rates that equal 25%, 50%, or 75% coverage after twenty years to assess the potential effects on HIV prevalence among MSM, requiring annual initiation rates of 2.5%, 6.8%, and 17.2% for Yaoundé and 2.2%, 5.6%, and 13.4% for Douala, respectively. The data utilized for this model are from a cross sectional study which recruited MSM through respondent-driven sampling of MSM in two major cities in Cameroon: Yaoundé and Douala.
The model estimated an HIV prevalence of 43.2% among MSM, annual HIV diagnoses of 300 per 10,000 MSM and antiretroviral therapy (ART) coverage of 53.9% in Yaoundé. In Douala, estimated prevalence is 26.5% among MSM, 167 per 10,000 MSM annual diagnoses and ART coverage of 72.0%. Standalone PrEP interventions aimed at 50% coverage at the end of a 20-year program would reduce the prevalence from 43.2% to 35.4% in Yaoundé and from 26.5 to 20.1% in Douala. Combining PrEP with a 10% increase in HIV testing would decrease the number of MSM living with HIV and unaware of their status from 9.8 to 6.0% in Yaoundé and from 8.7 to 4.6% in Douala.
PrEP would be beneficial in reducing prevalence even at varying initiation and coverage levels. Combination of PrEP and increased HIV testing further decreased the number of undiagnosed MSM. This study supports the utility of implementing PrEP as part of comprehensive HIV prevention programming among MSM in Cameroon.
男男性行为者（MSM）持续面临比其他成年人更高水平的 HIV 负担。尽管针对 MSM 的艾滋病毒预防方案在覆盖面和质量方面都有所增加，但 HIV 发病率仍然很高。因此，暴露前预防（PrEP）于 2019 年推出，以支持喀麦隆 MSM 降低 HIV 风险。了解 PrEP 启动计划将如何改变喀麦隆 MSM 中的 HIV 流行率，对于制定有效的计划非常重要。
本研究使用数学模型模拟喀麦隆雅温得和杜阿拉市 MSM 中的人群 HIV 传播。在 20 年后，PrEP 的覆盖率分别为 25%、50%或 75%，以评估其对 MSM 中 HIV 流行率的潜在影响，雅温得需要每年启动率为 2.5%、6.8%和 17.2%，杜阿拉分别为 2.2%、5.6%和 13.4%。该模型使用的数据来自一项横断面研究，该研究通过喀麦隆两个主要城市的 MSM 响应驱动抽样招募 MSM：雅温得和杜阿拉。
该模型估计 MSM 中的 HIV 流行率为 43.2%，每年每 10,000 名 MSM 中有 300 例 HIV 诊断，雅温得的抗逆转录病毒治疗（ART）覆盖率为 53.9%。在杜阿拉，MSM 中的估计流行率为 26.5%，每年每 10,000 名 MSM 中有 167 例 HIV 诊断，ART 覆盖率为 72.0%。在为期 20 年的项目结束时，针对 50%覆盖率的单独 PrEP 干预措施将使雅温得的流行率从 43.2%降至 35.4%，使杜阿拉的流行率从 26.5%降至 20.1%。将 PrEP 与 10%的 HIV 检测增加相结合，将使雅温得未确诊的 HIV 阳性 MSM 人数从 9.8%降至 6.0%，杜阿拉的未确诊 HIV 阳性 MSM 人数从 8.7%降至 4.6%。
PrEP 将有利于降低流行率，即使在不同的启动和覆盖水平下也是如此。PrEP 与增加 HIV 检测的结合进一步减少了未确诊的 MSM 人数。这项研究支持在喀麦隆 MSM 中实施 PrEP 作为综合艾滋病毒预防规划的一部分的实用性。
