Mudimu Edinah, Peebles Kathryn, Mukandavire Zindoga, Nightingale Emily, Sharma Monisha, Medley Graham F, Klein Daniel J, Kripke Katharine, Bershteyn Anna
Department of Decision Sciences, University of South Africa, Pretoria, South Africa.
Department of Global Health, University of Washington, Seattle, WA, United States of America.
PLoS One. 2020 Dec 31;15(12):e0244761. doi: 10.1371/journal.pone.0244761. eCollection 2020.
Pre-exposure prophylaxis (PrEP) is highly effective in preventing HIV and has the potential to significantly impact the HIV epidemic. Given limited resources for HIV prevention, identifying PrEP provision strategies that maximize impact is critical.
We used a stochastic individual-based network model to evaluate the direct (infections prevented among PrEP users) and indirect (infections prevented among non-PrEP users as a result of PrEP) benefits of PrEP, the person-years of PrEP required to prevent one HIV infection, and the community-level impact of providing PrEP to populations defined by gender and age in western Kenya and South Africa. We examined sensitivity of results to scale-up of antiretroviral therapy (ART) and voluntary medical male circumcision (VMMC) by comparing two scenarios: maintaining current coverage ("status quo") and rapid scale-up to meet programmatic targets ("fast-track").
The community-level impact of PrEP was greatest among women aged 15-24 due to high incidence, while PrEP use among men aged 15-24 yielded the highest proportion of indirect infections prevented in the community. These indirect infections prevented continue to increase over time (western Kenya: 0.4-5.5 (status quo); 0.4-4.9 (fast-track); South Africa: 0.5-1.8 (status quo); 0.5-3.0 (fast-track)) relative to direct infections prevented among PrEP users. The number of person-years of PrEP needed to prevent one HIV infection was lower (59 western Kenya and 69 in South Africa in the status quo scenario; 201 western Kenya and 87 in South Africa in the fast-track scenario) when PrEP was provided only to women compared with only to men over time horizons of up to 5 years, as the indirect benefits of providing PrEP to men accrue in later years.
Providing PrEP to women aged 15-24 prevents the greatest number of HIV infections per person-year of PrEP, but PrEP provision for young men also provides indirect benefits to women and to the community overall. This finding supports existing policies that prioritize PrEP use for young women, while also illuminating the community-level benefits of PrEP availability for men when resources permit.
暴露前预防（PrEP）在预防艾滋病毒方面非常有效，并且有可能对艾滋病毒流行产生重大影响。鉴于用于艾滋病毒预防的资源有限，确定能使影响最大化的PrEP提供策略至关重要。
我们使用了一个基于个体的随机网络模型来评估PrEP的直接益处（PrEP使用者中预防的感染）和间接益处（由于PrEP在非PrEP使用者中预防的感染）、预防一例艾滋病毒感染所需的PrEP人年数，以及在肯尼亚西部和南非按性别和年龄界定的人群中提供PrEP的社区层面影响。我们通过比较两种情景来检验结果对抗逆转录病毒疗法（ART）扩大规模和自愿男性包皮环切术（VMMC）的敏感性：维持当前覆盖率（“现状”）和快速扩大规模以实现规划目标（“快车道”）。
由于发病率高，PrEP在15 - 24岁女性中的社区层面影响最大，而15 - 24岁男性使用PrEP在社区中预防的间接感染比例最高。相对于PrEP使用者中预防的直接感染，这些预防的间接感染随时间持续增加（肯尼亚西部：0.4 - 5.5（现状）；0.4 - 4.9（快车道）；南非：0.5 - 1.8（现状）；0.5 - 3.0（快车道））。在长达5年的时间范围内，与仅向男性提供PrEP相比，仅向女性提供PrEP时预防一例艾滋病毒感染所需的PrEP人年数更低（肯尼亚西部现状情景下为59，南非为69；肯尼亚西部快车道情景下为201，南非为87），因为向男性提供PrEP的间接益处在后期才会显现。
向15 - 24岁女性提供PrEP每PrEP人年预防的艾滋病毒感染数量最多，但为年轻男性提供PrEP也会给女性和整个社区带来间接益处。这一发现支持了将PrEP用于年轻女性的现有政策，同时也说明了在资源允许时为男性提供PrEP在社区层面的益处。
