Objective: Using field epidemiological investigation and molecular analysis to construct the molecular transmission network of human immunodeficiency virus/acquired immunodeficiency syndrome cases (HIV/AIDS) newly diagnosed in Huzhou in 2017, Zhejiang Province. Methods: A total of 160 participants were obtained through a web-based system from Chinese Center for Disease Control and Prevention (CCDC) with the features of diagnosed in Huzhou in 2017 who also had been collected samples for the first follow-up. The basic information of demographic characteristics and risk factors was extracted from the website. RNA was extracted from plasma samples of untreated cases, followed by RT-PCR and nest-PCR for pol gene amplification, sequencing. Phylogenetic tree was constructed by MEGA software for HIV gene subtyping. TN93 model was used for calculating the distance between two sequences. Cytoscape software was used for drawing molecular transmission network. And then an epidemiological survey was conducted to cases in the primary cluster. Results: A total of 138 sequenced individuals (86.3%) were acquired from 160 individuals. Among which, 123 (89.1%) were male. The highest proportion of subtype was CRF07_BC (60, 43.5%), followed by CRF01_AE (46, 33.3%), and with four cases of Unique Recombinant Form (URF, CRF01_AE and CRF07_BC) and one case of URF (subtype B and C). A total of 18 molecular clusters included 56 individuals (40.6%) were found in the transmission network under the optimal genetic distance threshold (1.0%). The clustering proportion of CRF07_BC (66.1%, 37 cases) was higher than that of CRF01_AE. There were 9 clusters formed among CRF07_BC, including 37 cases (accounting for 61.7%, 37/60). The primary transmission cluster contained 11 cases, among which 9 cases were transmitted by homosexual sex. The first time of the cases to have homosexual behavior is range from 2010 to 2016, whose media number (P(25), P(75)) of partners was 6 (3.5, 8.5). Most of the cases come from Anhui Province and engaged in garment industry (5 cases), between which there were 8 cases used Blued software to seek for casual partners, 1 case seeking for casual partners in garden. Conclusion: With CRF07_BC and CRF01_AE predominantly circulating, HIV genetic diversity had been noticed in this area. The primary cluster was consisted of high proportion of locally new infections, and a specific population aggregation in limited place existed.
目的： 应用分子传播网络分析浙江省湖州市新发现HIV感染者和艾滋病患者（HIV/AIDS）的传播特征。 方法： 从"艾滋病综合防治数据信息管理系统"获取2017年新报告现住址在湖州市的HIV/AIDS为研究对象，并从系统中获得其人口学特征、感染相关危险因素等基本信息，采集研究对象全血6~8 ml，完成测序者共138例。使用MEGA 6.0软件构建邻接系统进化树进行亚型分析，使用TN93模型计算所有序列两两之间的基因距离，使用Cytoscape软件绘制筛选样本的分子传播网络图，对入网的主要传播簇病例开展专题流行病学调查，收集病例的基本特征，以及与HIV传播相关的信息。 结果： 男性为123例（89.1%）；19~24、25~39、40~59、≥60岁者分别为28（20.3%）、45（32.6%）、48（34.8%）和17例（12.3%）。亚型分析结果显示，CRF07_BC亚型所占比例最高，为43.5%（60例），其次为CRF01_AE亚型，为33.3%（46例），此外还发现4例CRF01_AE和CRF07_BC亚型的重组型，1例B和C亚型的重组型。以1.0%作为基因阈值构建分子传播网络，共形成18个分子簇，入网病例56例（40.6%），其中CRF07_BC亚型在网络中的构成比最高，为66.1%（37例）；该亚型共形成了9个传播簇，占CRF07_BC亚型所有病例数的61.7%（37/60），其中最主要传播簇包含了11例病例，且有9例是经男男同性性行为感染的，发生首次男男性性行为的时间为2010—2016年，同性性伴网络数的M（P(25)，P(75)）为6（3.5，8.5）名，以安徽户籍且从事服装行业者（5例）居多；9例男男性行为对象中，8例通过手机软件寻找非商业临时性伴，1例通过公园寻找非商业临时性伴。 结论： 湖州HIV亚型构成复杂多样，以CRF07_BC和CRF01_AE为主，主要传播簇本地新发感染构成比例高，且存在小范围特定人群的聚集现象。.
Keywords: HIV; Molecular epidemiology; Molecular transmission network; Molecular typing; Transmission characteristics.