Objective: To analyze HIV transmission hotspots and characteristics of cross-regional transmission in Guangxi Zhuang autonomous region (Guangxi) based on the molecular network analysis, and provide evidence for optimization of precise AIDS prevention and control strategies. Methods: A total of 5 996 HIV pol sequences sampled from Guangxi between 1997 and 2020 were analyzed together with 165 534 published HIV pol sequences sampled from other regions. HIV-TRACE was used to construct molecular network in a pairwise genetic distance threshold of 0.5%. Results: The proportion of HIV sequences entering the molecular network of HIV transmission hotspots in Guangxi was 31.5% (1 886/5 996). In the molecular network of HIV cross-regional transmission, the links within Guangxi accounted for 51.6% (2 613/5 062), the links between Guangxi and other provinces in China accounted for 48.0% (2 430/5 062), and the links between Guangxi and other countries accounted for 0.4% (19/5 062). The main regions which had cross-regional linked with Guangxi were Guangdong (49.5%, 1 212/2 449), Beijing (17.5%, 430/2 449), Shanghai (6.9%, 168/2 449), Sichuan (5.7%, 140/2 449), Yunnan (4.2%, 102/2 449), Shaanxi (3.8%, 93/2 449), Zhejiang (2.8%, 69/2 449), Hainan (2.0%, 49/2 449), Anhui (1.5%, 37/2 449), Jiangsu (1.3%, 33/2 449), and other regions (each one <1.0%), respectively. The risk factors of entering the molecular network of HIV transmission hotspots in Guangxi included being aged ≥50 years (compared with being aged 25-49 years, aOR=1.68,95%CI:1.46-1.95), males (compared with females, aOR=1.21,95%CI:1.05-1.40), being single (compared with being married, aOR=1.18,95%CI:1.00-1.39), having education level of high school or above (compared with having education level of junior high school or below, aOR=1.21,95%CI:1.04-1.42), acquired HIV through homosexual intercourse (compared with acquired with HIV through heterosexual intercourse, aOR=1.77, 95%CI:1.48-2.12). The risk factors of cross-regional transmission included males (compared with females, aOR=1.74,95%CI:1.13-2.75), having education level of high school or above (compared with having education level of junior high school or below, aOR=1.96,95%CI:1.43-2.69), being freelancer/unemployed/retired (compared with being farmers, aOR=1.50,95%CI:1.07-2.11), acquired HIV through homosexual intercourse (compared with acquired with HIV through heterosexual intercourse, aOR=3.28,95%CI:2.30-4.72). Conclusion: There are HIV transmission hotspots in Guangxi. Guangxi and other provinces in China form a complex cross-regional transmission network. Future studies should carry out social network surveys in high-risk populations inferred from the molecular network analysis for the timely identification of hidden transmission chains and reduction of the second-generation transmission of HIV.
目的： 基于分子网络分析广西壮族自治区（广西）HIV传播热点和跨地区传播特征，为优化艾滋病精准防控策略提供证据。 方法： 整合1997-2020年采集的5 996条广西HIV pol区序列和165 534条公开发表的非广西HIV pol区序列，使用HIV-TRACE工具以0.5%成对基因距离阈值构建分子网络。 结果： 进入广西HIV传播热点分子网络的序列比例为31.5%（1 886/5 996）。在HIV跨地区传播分子网络中，省内连接占51.6%（2 613/5 062），国内连接占48.0%（2 430/5 062），国际连接占0.4%（19/5 062）。与广西跨地区连接的主要地区为广东省（49.5%，1 212/2 449）、北京市（17.5%，430/2 449）、上海市（6.9%，168/2 449）、四川省（5.7%，140/2 449）、云南省（4.2%，102/2 449）、陕西省（3.8%，93/2 449）、浙江省（2.8%，69/2 449）、海南省（2.0%，49/2 449）、安徽省（1.5%，37/2 449）和江苏省（1.3%，33/2 449），其余地区与广西跨地区连接比例均<1.0%。进入广西HIV传播热点分子网络风险较高的影响因素包括≥50岁（相比于25~49岁，aOR=1.68，95%CI：1.46~1.95）、男性（相比于女性，aOR=1.21，95%CI：1.05~1.40）、未婚（相比于已婚，aOR=1.18，95%CI：1.00~1.39）、高中及以上文化程度（相比于初中及以下，aOR=1.21，95%CI：1.04~1.42）和男男性传播（相比于异性性传播，aOR=1.77，95%CI：1.48~2.12）。跨地区连接风险较高的影响因素包括男性（相比于女性：aOR=1.74，95%CI：1.13~2.75），高中及以上文化程度（相比于初中及以下，aOR=1.96，95%CI：1.43~2.69）、自由职业/待业/退休（相比于农民，aOR=1.50，95%CI：1.07~2.11）、男男性传播（相比于异性性传播，aOR=3.28，95%CI：2.30~4.72）。 结论： 广西存在HIV传播热点，广西与国内地区组成复杂的跨地区传播网络。后续研究应针对分子网络分析推断的高风险人群开展社会网络调查，及时识别隐匿传播链，减少HIV二代传播。.