Abstract：
Using a comprehensive molecular epidemiological approach, we characterized the transmission dynamics of HIV-1 among the MSM population in Tianjin, China. Our findings revealed that 38.56% (386/1001) of individuals clustered across 109 molecular transmission clusters (TCs), with MSM aged 50 and below being the group most commonly transmitting HIV-1. Among the identified TCs, CRF01_AE predominated, followed by CRF07_BC. Notably, CRF07_BC demonstrated a higher propensity for forming large clusters compared to CRF01_AE. Birth-death skyline analyses of the two largest clusters indicated that the HIV/AIDS transmission may be at a critical point, nearly all had Re approximately 1 by now. A retrospective analysis revealed that the rapid expansion of these large clusters was primarily driven by the introduction of viruses in 2021, highlighting the crucial importance of continuous molecular surveillance in identifying newly emerging high-risk transmission chains and adapting measures to address evolving epidemic dynamics. Furthermore, we detected the transmission of drug-resistant mutations (DRMs) within the TCs, particularly in the CRF07_BC clusters (K103N, Y181C, and K101E) and CRF01_AE clusters (P225H and K219R), emphasizing the importance of monitoring to support the continued efficacy of first-line therapies and pre-exposure prophylaxis (PrEP). Recombination analyses indicated that complex recombinant patterns, associated with increased amino acid variability, could confer adaptive traits to the viruses, potentially providing a competitive advantage in certain host populations or regions. Our study highlights the potential of integrating molecular epidemiological and phylodynamic approaches to inform targeted interventions.
摘要：
使用全面的分子流行病学方法，我们表征了HIV-1在天津市MSM人群中的传播动态，中国。我们的研究结果表明，38.56%(386/1001)的个体聚集在109个分子传输簇(TC)中，50岁及以下的MSM是最常见的HIV-1传播群体。在确定的TC中，CRF01_AE占主导地位，其次是CRF07_BC。值得注意的是,与CRF01_AE相比,CRF07_BC表现出更高的形成大簇的倾向。对两个最大集群的出生-死亡天际线分析表明，艾滋病毒/艾滋病的传播可能处于临界点，到现在为止，几乎所有人都有Re大约1。回顾性分析显示，这些大型集群的快速扩张主要是由于2021年病毒的引入，突出了连续分子监测在识别新出现的高风险传播链和调整措施以应对不断变化的流行病动态方面的至关重要性。此外，我们检测到耐药突变（DRMs）在TC内的传播，特别是在CRF07_BC集群中(K103N，Y181C,和K101E)和CRF01_AE簇(P225H和K219R)，强调监测的重要性，以支持一线治疗和暴露前预防（PrEP）的持续疗效。重组分析表明，复杂的重组模式，与氨基酸变异性增加相关，可以赋予病毒适应性特征，在某些宿主群体或地区可能提供竞争优势。我们的研究强调了整合分子流行病学和系统动力学方法以告知有针对性的干预措施的潜力。
