Volz Erik M, Ndembi Nicaise, Nowak Rebecca, Kijak Gustavo H, Idoko John, Dakum Patrick, Royal Walter, Baral Stefan, Dybul Mark, Blattner William A, Charurat Man
Department of Infectious Disease Epidemiology, Imperial College, London, Norfolk Place W2 1PG, UK.
Institute of Human Virology Nigeria, Herbert Macaulay Way, Abuja, Nigeria.
Virus Evol. 2017 Jul 28;3(2):vex014. doi: 10.1093/ve/vex014. eCollection 2017 Jul.
In HIV epidemics of Sub Saharan Africa, the utility of HIV prevention efforts focused on key populations at higher risk of HIV infection and transmission is unclear. We conducted a phylodynamic analysis of HIV-1 sequences from four different risk groups in Abuja, Nigeria to estimate transmission patterns between men who have sex with men (MSM) and a representative sample of newly enrolled treatment naive HIV clients without clearly recorded HIV acquisition risks. We develop a realistic dynamical infectious disease model which was fitted to time-scaled phylogenies for subtypes G and CRF02_AG using a structured-coalescent approach. We compare the infectious disease model and structured coalescent to commonly used genetic clustering methods. We estimate HIV incidence among MSM of 7.9% (95%CI, 7.0-10.4) per susceptible person-year, and the population attributable fraction of HIV transmissions from MSM to reproductive age females to be 9.1% (95%CI, 3.8-18.6), and from the reproductive age women to MSM as 0.2% (95%CI, 0.06-0.3). Applying these parameter estimates to evaluate a test-and-treat HIV strategy that target MSM reduces the total HIV infections averted by half with a 2.5-fold saving. These results suggest the importance of addressing the HIV treatment needs of MSM in addition to cost-effectiveness of specific scale-up of treatment for MSM in the context of the mixed HIV epidemic observed in Nigeria.
在撒哈拉以南非洲的艾滋病流行中，针对艾滋病病毒感染和传播风险较高的重点人群的预防措施的效用尚不清楚。我们对尼日利亚阿布贾四个不同风险组的HIV-1序列进行了系统动力学分析，以估计男男性行为者（MSM）与新登记的未明确记录艾滋病病毒感染风险的初治艾滋病病毒感染者代表性样本之间的传播模式。我们开发了一个现实的动态传染病模型，该模型使用结构化合并方法拟合了G亚型和CRF02_AG亚型的时间尺度系统发育树。我们将传染病模型和结构化合并与常用的基因聚类方法进行了比较。我们估计男男性行为者中艾滋病病毒发病率为每易感人年7.9%（95%置信区间，7.0-10.4），男男性行为者向育龄女性传播艾滋病病毒的人群归因分数为9.1%（95%置信区间，3.8-18.6），育龄女性向男男性行为者传播的归因分数为0.2%（95%置信区间，0.06-0.3）。应用这些参数估计值来评估针对男男性行为者的检测和治疗艾滋病病毒策略，可将避免的艾滋病病毒总感染数减少一半，并节省2.5倍的成本。这些结果表明，在尼日利亚观察到的混合艾滋病疫情背景下，除了扩大针对男男性行为者的治疗的成本效益外，满足男男性行为者的艾滋病病毒治疗需求也很重要。
