Brief communication: characteristics of primary drug resistance in newly diagnosed HIV-infected individuals in Ganzhou, China.

Background: Primary drug resistance (PDR) is an important cause of antiretroviral therapy (ART) failure. However, the prevalence and characteristics of PDR in Ganzhou remain unclear.

Methods: From July 2018 to August 2021, treatment-naïve, newly diagnosed HIV-infected individuals in Ganzhou, China were recruited. Blood samples were collected, and the HIV pol gene was amplified by nested PCR followed by Sanger sequencing. Sequence editing and assembly were performed using DNASTAR Lasergene software, and subsequent analysis for resistance mutations and drug susceptibility profiling was conducted using the Stanford University HIV Drug Resistance Database.

Results: Among 108 successfully amplified samples, seven exhibited low-, intermediate-, or high-level resistance mutations, resulting in a PDR prevalence of 6.5%. Among them, the mutation rate of non-nucleoside reverse transcriptase inhibitors (NNRTIs) was 4.6%, and the drug resistance mutation rates of nucleoside reverse transcriptase inhibitors and integrase strand transfer inhibitors (INSTIs) were both 0.9%. No protease inhibitor resistance was detected. Nine drug resistance mutations were detected, among which six were related to NNRTIs, one was related to nucleoside reverse transcriptase inhibitors, and two were related to INSTIs. The K103N and Y181C mutations conferred intermediate-to-high resistance to NNRTIs, while A98G and V179E caused low-to-intermediate resistance to NNRTIs, and the remaining mutations led to low drug resistance to the respective drugs.

Conclusions: Compared to other regions in China, Ganzhou exhibits a relatively low PDR among newly diagnosed HIV-infected individuals. However, the emergence of INSTI-resistant strains underscores the need for enhanced resistance surveillance to prevent the spread of drug-resistant strains caused by ART failure.