[Analysis of HIV transmission hotspots and characteristics of cross-regional transmission in Guangxi Zhuang Autonomous Region based on molecular network].

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. A total of 5 996 HIV sequences sampled from Guangxi between 1997 and 2020 were analyzed together with 165 534 published HIV sequences sampled from other regions. HIV-TRACE was used to construct molecular network in a pairwise genetic distance threshold of 0.5%. 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, a=1.68,95%:1.46-1.95), males (compared with females, a=1.21,95%:1.05-1.40), being single (compared with being married, a=1.18,95%:1.00-1.39), having education level of high school or above (compared with having education level of junior high school or below, a=1.21,95%:1.04-1.42), acquired HIV through homosexual intercourse (compared with acquired with HIV through heterosexual intercourse, a=1.77, 95%:1.48-2.12). The risk factors of cross-regional transmission included males (compared with females, a=1.74,95%:1.13-2.75), having education level of high school or above (compared with having education level of junior high school or below, a=1.96,95%:1.43-2.69), being freelancer/unemployed/retired (compared with being farmers, a=1.50,95%:1.07-2.11), acquired HIV through homosexual intercourse (compared with acquired with HIV through heterosexual intercourse, a=3.28,95%:2.30-4.72). 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.