Drug Resistance Profile Among HIV-1 Infections Experiencing ART with Low-Level Viral Load in Guangdong China During 2011–2022: A Retrospective Study

Background: Antiretroviral therapy (ART) efficiently reduces the morbidities and mortalities caused by HIV-1 infection and prevents the HIV epidemic. However, virologic failure (VF) occurs in some patients receiving ART experience, especially increases in those patients with intermittent or persistent low-level viremia (LLV). The presence of drug resistance mutations (DRMs) in LLV was a strong predictor of subsequent VF. The data on drug resistance (DR) or DRMs for HIV-1 infections at low-level viral load (LLVL) are limited in China. Objective: To monitor the prevalence of HIV-1 drug resistance and to evaluate the risk factors associated with drug resistance in LLVL HIV-1 infections during ART in Guangdong, China. Methods: Plasma samples with LLVL during ART in Guangdong Province between Jan 2011 and Dec 2022 were subjected to a modified reverse-transcription PCR with a pre-step of virus concentration by ultracentrifugation before extraction and the Sanger sequencing. Then, the genotypic resistance test was performed and DR was analyzed by the Stanford HIVDB program. Finally, DR-associated factors were identified by logistic regression analysis. Results: We found that CRF01_AE (53.57%) and CRF07_BC (25.07%) were the dominant HIV-1 genotypes in LLVL in Guangdong between 2011 and 2022 but that the percentage of CRF01_AE showed a trend of decrease over time. M46 (1.49%), M184 (30.91%), and K103 (21.46%) were the dominant PI-, NRTI-, and NNRTI-associated mutations, respectively. The total DR rate was 47.06%. Specifically, PI (3.71%) showed a significantly lower DR rate than NNRTI (40.74%) and NRTI (34.14%). Duration of ART, initial ART regimen, ethnicity, and WHO clinical stages were associated with DR. Conclusion: The drug resistance rate among the LLVL during ART in Guangdong, China is high. The risk factors associated with HIV drug resistance should be seriously considered for better control.