Drug resistance and molecular transmission network analysis based on newly diagnosed HIV/AIDS individuals in Beijing, China: A retrospective study from 2015 to 2023

Background Systematic surveillance of HIV genetic diversity, transmitted drug resistance (TDR) and transmission networks in newly diagnosed people living with HIV/AIDS (PLWHA) in Beijing has rarely been reported. This retrospective study aimed to analyze data of PLWHA from 2015 to 2023 in Beijing to develop precision interventions. Methods All newly diagnosed PLWHA were subjected to sequence splicing, quality control, information matching, and analysis for TDR and genetic transmission networks. The Stanford Drug Resistance Database was used to analyze drug resistance, and Hyphy and Cytoscape software were used to construct a genetic transmission network with a gene distance threshold of 0.02. Results A total of 3569 newly diagnosed PLWHA were included in this study. A total of 25 HIV-1 genotypes were identified, with CRF01_AE being the most common genotype, followed by the CRF07_BC and B genotypes. However, for the first time, the dominant strain shifted from CRF01_AE to CRF07_BC in 2020. A total of 340 drug-resistant sequences were obtained, and the total TDR was 9.53% from 2015 to 2023. The most common mutations were distributed among V179, V106, S68, M184 and M46, which exhibited diverse distributions and combined mutation features. A total of 76 transmission clusters were identified in the network, among which CRF07_BC was dominated by large, fast-spreading clusters, whereas CRF01_AE was dominated by small- and medium-sized slow-spreading clusters. The largest cluster for CRF07_BC expanded rapidly from 11 cases in 2015 to 496 cases in 2023. Conclusions This study revealed the prevalence of HIV-1 drug resistance and molecular transmission clusters in Beijing. The change in the dominant HIV strain in Beijing should be emphasized. Subtype CRF07_BC is prone to forming fast-spreading clusters, and targeted interventions should be designed to obstruct high-risk transmission sources and reduce new HIV infections.