{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,13]],"date-time":"2026-07-13T16:21:08Z","timestamp":1783959668919,"version":"3.55.0"},"reference-count":30,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,3,9]],"date-time":"2026-03-09T00:00:00Z","timestamp":1773014400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Microbiol."],"abstract":"<jats:p>Guangxi is one of the regions most affected by HIV-1 in China, yet the fine-scale transmission dynamics and molecular epidemiology remain incompletely characterized. In this study, we integrated molecular transmission network analysis, phylogenetic inference, and spatial analysis to elucidate HIV-1 dispersal patterns and inform precision public health interventions. We analyzed 10,199 HIV-1 pol sequences collected from all 14 cities in Guangxi, encompassing major subtypes including CRF01_AE, CRF07_BC, CRF08_BC, and CRF55_01B. Molecular networks were constructed using a 1.5% TN93 genetic-distance threshold, and logistic regression was applied to identify factors associated with network clustering. Bayesian phylogenetic and phylogeographic analyses were used to characterize spatiotemporal dissemination patterns. Overall, 75.6% (7,706\/10,199) of individuals clustered within molecular networks, with clustering proportions exceeding 60% in every city. Factors independently associated with clustering included viral load &amp;gt;10,000 copies\/mL (OR\u202f=\u202f1.23, 95% CI: 1.10\u20131.39), education level of junior high school or below (OR\u202f=\u202f1.67, 95% CI: 1.30\u20132.14), age \u226550\u202fyears (OR\u202f=\u202f1.38, 95% CI: 1.16\u20131.63), Zhuang ethnicity (OR\u202f=\u202f1.18, 95% CI: 1.08\u20131.30), and syringe sharing (OR\u202f=\u202f1.65, 95% CI: 1.14\u20132.38). Intercity connections accounted for 48.2% of inferred genetic linkages, with CRF55_01B showing the highest intercity connectivity (60.4%). CRF01_AE displayed the broadest geographic distribution, Nanning and Qinzhou emerged as key connectivity hubs. Phylogeographic analyses suggested that Qinzhou was a major source of dispersal for CRF01_AE and CRF08_BC, whereas Nanning played a central role in the dissemination of CRF07_BC, CRF08_BC, and CRF55_01B. HIV-1 transmission in Guangxi is characterized by high network clustering and pronounced spatial heterogeneity, with distinct hub cities contributing to regional connectivity. These findings provide actionable evidence to support targeted, location-specific HIV prevention and control strategies at both local and regional levels.<\/jats:p>","DOI":"10.3389\/fmicb.2026.1761072","type":"journal-article","created":{"date-parts":[[2026,3,9]],"date-time":"2026-03-09T13:55:33Z","timestamp":1773064533000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Unraveling HIV-1 spread in Southwest China: a phylogenetic and molecular network approach"],"prefix":"10.3389","volume":"17","author":[{"given":"Xianwu","family":"Pang","sequence":"first","affiliation":[{"name":"Guangxi Key Laboratory for the Prevention and Control of Viral Hepatitis, Guangxi Key Laboratory of AIDS Prevention and Control and Achievement Transformation, Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention","place":["Nanning, Guangxi, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kailing","family":"Tang","sequence":"additional","affiliation":[{"name":"Guangxi Key Laboratory for the Prevention and Control of Viral Hepatitis, Guangxi Key Laboratory of AIDS Prevention and Control and Achievement Transformation, Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention","place":["Nanning, Guangxi, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qin","family":"He","sequence":"additional","affiliation":[{"name":"Guangxi Key Laboratory for the Prevention and Control of Viral Hepatitis, Guangxi Key Laboratory of AIDS Prevention and Control and Achievement Transformation, Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention","place":["Nanning, Guangxi, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jie","family":"Ma","sequence":"additional","affiliation":[{"name":"Guangxi Key Laboratory for the Prevention and Control of Viral Hepatitis, Guangxi Key Laboratory of AIDS Prevention and Control and Achievement Transformation, Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention","place":["Nanning, Guangxi, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ningye","family":"Fang","sequence":"additional","affiliation":[{"name":"Guangxi Key Laboratory for the Prevention and Control of Viral Hepatitis, Guangxi Key Laboratory of AIDS Prevention and Control and Achievement Transformation, Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention","place":["Nanning, Guangxi, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haomin","family":"Xie","sequence":"additional","affiliation":[{"name":"Guangxi Key Laboratory for the Prevention and Control of Viral Hepatitis, Guangxi Key Laboratory of AIDS Prevention and Control and Achievement Transformation, Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention","place":["Nanning, Guangxi, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ge","family":"Zhong","sequence":"additional","affiliation":[{"name":"Guangxi Key Laboratory for the Prevention and Control of Viral Hepatitis, Guangxi Key Laboratory of AIDS Prevention and Control and Achievement Transformation, Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention","place":["Nanning, Guangxi, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shujia","family":"Liang","sequence":"additional","affiliation":[{"name":"Guangxi Key Laboratory for the Prevention and Control of Viral Hepatitis, Guangxi Key Laboratory of AIDS Prevention and Control and Achievement Transformation, Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention","place":["Nanning, Guangxi, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,3,9]]},"reference":[{"key":"ref1","doi-asserted-by":"crossref","first-page":"1135","DOI":"10.1093\/cid\/cis612","article-title":"Characterizing HIV transmission networks across the United States","volume":"55","author":"Aldous","year":"2012","journal-title":"Clin. 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