The Prevalence of Pretreatment Drug Resistance and Transmission Networks Among Newly Diagnosed HIV-1-Infected Individuals in Nanning, Guangxi, China

The scale-up of antiretroviral therapy (ART) has markedly increased pretreatment drug resistance (PDR) among newly diagnosed HIV-infected individuals. This study aims to assess the prevalence and characteristics of PDR, infer the genetic transmission network, and evaluate the effect of PDR on ART in Nanning City, Guangxi. Methods: This study was conducted in the Fourth People's Hospital of Nanning from 2019 to 2023. PDR was estimated using the Stanford algorithm. Genetic transmission networks were inferred by HIV-TRACE and visualized with Cytoscape. Logistic regression identified PDR-related factors. The Cox proportional hazards model assessed the impact of drug resistance on virological and immunological failure. Among 234 participants, the prevalence of PDR was 8.97%. CRF07_BC (35.9%), CRF-01AE (27.35%), and CRF08_BC (23.9%) were the top three HIV-1 strains. Resistance to non-nucleoside reverse-transcriptase inhibitors, protease inhibitors, nucleoside reverse-transcriptase inhibitors, and integrase strand-transfer inhibitors was 4.27%, 2.56%, 1.28%, and 0.43%, respectively. Overall, 21.37% of the participants exhibited drug resistance mutations (DRMs). Homosexuals were less likely to have PDR compared to heterosexuals ([aOR] 0.09, 95% CI 0.01-0.86). In the genetic network, V179D/E was also the most frequent DRM. Additionally, the incidence of virological failure (19.23%) and immune failure (20.09%) after one year of treatment did not show significant differences in different drug resistance groups. Conclusions: The prevalence of PDR in Nanning City is moderate, driven largely by the V179D and K103N mutations. The cross-transmission networks emphasize the imperative of PDR testing and targeted interventions.