Objective: To analyze the characteristics of HIV-1 molecular network in men who have sex with men (MSM) from 2016 to 2018 in Kunming, Yunnan province, explore the risk factors associated with HIV-1 transmission network and provide evidence for the effective implementation of intervention. Methods: A total of 540 samples of newly reported HIV-1 positive MSM were consecutively collected in Kunming from 2016 to 2018, the pol gene fragments were amplified by nested polymerase chain reaction (PCR). HIV-1 molecular networks were constructed according to the bootstrap value of the maximum likelihood evolutionary tree over 95% and the genetic distance less than 3%. The factors associated with the subjects entering network and network growth were further analyzed. Results: Among 459 successfully sequenced samples, seven genotypes were found, in which CRF07_BC (49.2%, 226/459) and CRF01_AE (40.3%, 185/459 ) were predominant. Other genotypes included URFs (4.8%, 22/459), CRF08_BC (3.1%, 14/459), CRF55_01B (1.7%, 8/459), B (0.7%, 3/459) and CRF68_01B (0.2%, 1/459). A total of 163 sequences entered the network, with an entry rate of 35.5%(163/459), forming 56 clusters with the number of individuals in the cluster was between 2 and 13. The analysis of the factors associated with entering network showed that the MSM who married and had multiple homosexual partners were more likely to be found in HIV-1 molecular networks. Multivariate logistic regression analysis showed that the number of sexual partners was the factor for the growth of HIV-1 molecular network. According to the criteria for the emergence of three or more newly reported cases in every year, six transmission clusters were judged as active transmission clusters, in which MSM who were not Kunming natives, had sexually transmitted diseases (STD), were divorced and students were the key targets of intervention. Conclusions: HIV-1 genotypes in MSM in Kunming were becoming complex, the risk factors associated with transmission networks in MSM in Kunming included being married and having multiple partners, the intervention targets in active transmission clusters included MSM who were not Kunming natives, had STD, were divorced and students. This study provided the basis for applying HIV-1 molecular networks to real-time intervention in this population.
目的： 分析云南省昆明市2016－2018年MSM中HIV-1分子网络的特征，探讨HIV-1传播网络的危险因素，为干预的有效实施提供依据。 方法： 2016－2018年在昆明市连续收集新报告的感染HIV-1的MSM的样品540份，通过巢式PCR扩增HIV-1的pol区基因，按照最大似然进化树中bootstrap值>95%和基因距离<3%构建分子网络，对研究对象进入网络和网络增长的相关因素进行分析。 结果： 459份样品获得pol序列，检测到7种HIV-1基因型，其中以CRF07_BC（49.2%，226/459）和CRF01_AE（40.3%，185/459）为主，其他基因型包括URFs（4.8%，22/459）、CRF08_BC（3.1%，14/459）、CRF55_01B（1.7%，8/459）、B亚型（0.7%，3/459）和CRF68_01B（0.2%，1/459）。共163条序列进入网络，入网率为35.5%（163/459），形成56个簇，簇内个体数在2～13个之间。对研究对象进入网络的影响因素分析，发现已婚和多性伴者在网络中检测到的比例较大；多因素logistic回归分析结果显示，性伴数是MSM感染者分子网络增长的影响因素；按照每年出现≥3个新增感染者的网络为活跃传播簇的标准，有6个传播簇可判定为活跃传播簇，外地、有STD史、离异和学生的MSM是活跃传播簇干预的关键对象。 结论： 昆明市MSM中HIV-1基因型日趋复杂，进入分子网络的相关因素包括已婚和多性伴，活跃传播簇中外地、有STD史、离异和学生MSM需要加强干预，本研究为分子网络运用于该人群的干预提供了基础。.
Keywords: HIV-1; Men who have sex with men; Molecular network.