Abstract:
Objective To analyze the transmission of drug resistance and molecular network characteristics of newly reported HIV-1 infection cases in Gulou district of Nanjing, Jiangsu province, from 2015 to 2023, and provide data support for the targeted intervention against HIV infection.
Methods Plasma samples were collected from the newly reported and untreated HIV-1 infection cases in Gulou from 2015 and 2023, and the HIV-1 pol region was amplified by reverse transcription-nested PCR. Phylogenetic trees were constructed to identify HIV-1 subtypes, and molecular transmission networks were established at a genetic distance threshold of 1.45%. Drug resistance profiles were analyzed by using the HIV Drug Resistance Database of Stanford University.
Results A total of 409 HIV-1 gene sequences and 10 genotypes were obtained. The predominant subtypes were CRF01_AE (164/409, 40.10%) and CRF07_BC (131/409, 32.03%), followed by CRF119_0107 (36/409, 8.80%) and CRF67_01B (23/409, 5.62%). The rate of pretreatment drug resistance (PDR) was 6.11% (25/409), and the resistance rates to non-nucleoside reverse transcriptase inhibitors (NNRTIs), nucleoside reverse transcriptase inhibitors, and protease inhibitors were 4.16% (17/409), 0.49% (2/409), and 1.47% (6/409), respectively. Meanwhile, the rate of transmitted drug resistance (TDR) was 3.42% (14/409) in surveillance, with drug resistance mutations being K103N, Y181C, P225H, T215S, L90M, M46I, M46L, N83D, and N88D. A total of 140 cases were connected to the network with an access rate of 34.23%. Seven drug-resistant cases were identified within 4 transmission clusters (28.00%, 7/25), with NNRTI resistance accounting for the highest proportion (71.43%, 5/7). The predominant TDR mutation was K103N (57.14%, 4/7), which was mainly found in CRF07_BC and CRF01_AE transmission clusters.
Conclusion The subtypes of HIV-1 detected in Gulou were complex, the PDR rate exceeded 5%, and the transmission clusters harboring drug-resistant strains emerged. Therefore, it is necessary to strengthen the dynamic surveillance for drug-resistant strains and drug-resistant transmission clusters and take targeted measures for the prevention and control of the spread of drug-resistant strains.