Analysis of ART effects and drug resistance in adult HIV/AIDS patients in Meigu County, Liangshan Prefecture, China.

Background Objective: This study aimed to understand the basic situation of adults with human immunodeficiency virus (HIV) receiving antiretroviral therapy (ART) in Meigu County, Liangshan Yi Autonomous Prefecture. The information of patients who had been on ART for more than 6 months, the effect of ART, the possible reasons for ART failure, knowledge of drug resistance among patients with ART failure and the possible reasons for the emergence of drug resistance were analyzed.

Methods: A total of 2753 people living with HIV (PLWH) were collected for HIV-1 RNA virus nucleic acid testing. Plasma specimens with HIV-1 RNA ≥ 1000 copies/mL were sent to the laboratory for nucleic acid extraction, PCR, electrophoresis and sequencing, and the sequencing results were submitted to the HIV drug resistance database of Stanford University for subtyping to determine the drug resistance mutation sites and drug sensitivity levels.

Results: A total of 2753 patients were enrolled in this study. Antiviral therapy failed in 288 patients and was successfully amplified in 245, of which 111 had resistance genes. The resistance rate to failure of viral suppression was 45.3% (111/245). The highest rates of resistance to NNRTIs were found for efavirenz (EFV) and nevirapine (NVP) (42.9%), and the highest rates of resistance to NRTIs were found for 3TC and emtricitabine (FTC) (15.9%). The most common NNRTI resistance mutation site was K103N (20.8%), followed by V179D (9.4%) and V106M (7.8%); the most common NRTI resistance mutation site was M184V/I/MV (14.3%), followed by K65R (6.9%); three PI-associated resistance mutation sites were identified. The subtype of the resistant strain was CRF07-BC in almost all patients (98.9%).

Conclusions: Compared with the previous low ART efficacy in the county, this study showed that the overall virological failure (VF) resistance rate in the county is still low, dominated by resistance to EFV, NVP, 3TC, FTC, and didanosine (DDI). Due to economic constraints, the core regimen is still 3TC + TDF, but before initiating ART, testing for HIV-1 subtypes and resistance should be conducted to avoid resistance that can lead to VF, especially for patients with high risk factors for resistance as shown by epidemiologic investigations.