Table_2_Exploring Evolutionary and Transmission Dynamics of HIV Epidemic in Serbia: Bridging Socio-Demographic With Phylogenetic Approach.DOCX

Previous molecular studies of Serbian HIV epidemic identified the dominance of subtype B and presence of clusters related HIV-1 transmission, in particular among men who have sex with men (MSM). In order to get a deeper understanding of the complexities of HIV sub-epidemics in Serbia, epidemic trends, temporal origin and phylodynamic characteristics in general population and subpopulations were analyzed by means of mathematical modeling, phylogenetic analysis and latent class analysis (LCA). Fitting of the logistic curve of trends for a cumulative annual number of new HIV cases in 1984–2016, in general population and MSM transmission group, was performed. Both datasets fitted the logistic growth model, showing the early exponential phase of the growth curve. According to the suggested model, in the year 2030, the number of newly diagnosed HIV cases in Serbia will continue to grow, in particular in the MSM transmission group. Further, a detailed phylogenetic analysis was performed on 385 sequences from the period 1997–2015. Identification of transmission clusters, estimation of population growth (Ne), of the effective reproductive number (Re) and time of the most recent common ancestor (tMRCA) were estimated employing Bayesian and maximum likelihood methods. A substantial proportion of 53% of subtype B sequences was found within transmission clusters/network. Phylodynamic analysis revealed Re over one during the whole period investigated, with the steepest slopes and a recent tMRCA for MSM transmission group subtype B clades, in line with a growing trend in the number of transmissions in years approaching the end of the study period. Contrary, heterosexual clades in both studied subtypes – B and C – showed modest growth and stagnation. LCA analysis identified five latent classes, with transmission clusters dominantly present in 2/5 classes, linked to MSM transmission living in the capital city and with the high prevalence of co-infection with HBV and/or other STIs.Presented findings imply that HIV epidemic in Serbia is still in the exponential growth phase, in particular, related to the MSM transmission, with estimated steep growth curve until 2030. The obtained results imply that an average new HIV patient in Serbia is a young man with concomitant sexually transmitted infection.

先前对塞尔维亚HIV流行病的分子学研究揭示了B亚型的主导地位以及与男性同性恋者（MSM）相关的HIV-1传播集群的存在。为了深入理解塞尔维亚HIV亚流行病的复杂性，本研究通过数学建模、系统发育分析和潜在类别分析（LCA）对总人口和亚群体中的流行趋势、时间起源和群体动力学特征进行了分析。对1984年至2016年总人口和MSM传播群体累计年度新HIV病例数的趋势对数曲线进行了拟合。两个数据集均符合对数增长模型，显示出增长曲线的早期指数阶段。根据所提出的模型，预计到2030年，塞尔维亚新诊断的HIV病例数将继续增长，尤其是在MSM传播群体中。此外，对1997年至2015年期间的385个序列进行了详细的系统发育分析。通过贝叶斯和最大似然方法，确定了传播集群，估计了种群增长率（Ne）、有效再生数（Re）和最近共同祖先（tMRCA）的时间。在传播集群/网络中发现，53%的B亚型序列属于传播集群。群体动力学分析显示，在整个研究期间，Re均超过1，MSM传播群体B亚型分支的斜率最陡，最近tMRCA，这与研究期末年份传播数量增加的趋势一致。相反，在两种研究亚型（B型和C型）的异性恋分支中均表现出适度增长和停滞。LCA分析确定了五个潜在类别，其中2/5的类别中存在传播集群，与居住在首都的MSM传播者相关，并且HBV和/或其他性传播感染（STIs）的共感染发生率较高。所获得的结果表明，塞尔维亚的HIV流行病仍处于指数增长阶段，尤其是与MSM传播相关，预计到2030年将保持陡峭的增长曲线。所得结果暗示，塞尔维亚的平均新HIV患者为年轻的男性，伴有性传播感染。