Molecular network characteristics and drug resistance analysis of 392
newly reported MSM HIV/AIDS cases in Chongqing, China
Abstract
To comprehensively investigate the molecular transmission patterns of
HIV-1 genotypes among men who have sex with men (MSM) in Chongqing, we
employed 392 pol sequences of MSM to construct a phylogenetic tree and
gene transmission network. The study collected a total of 392 sequences
for analysis. Among the viral subtypes, CRF07_BC accounted for 73.2%
(287/392) and CRF01_AE accounted for 20.7% (81/392), emerging as the
predominant subtypes in this investigation. Additionally, we observed
the presence of CRF55_01B, CRF59_01B, subtype B, CRF08_BC and other
circulating recombinant forms in consecutive detections. The HIV-1
molecular network was constructed with a gene distance threshold of
1.5%, resulting in an entry rate of 61.4% (241/392). Within the
network, we identified a total of 23 molecular clusters, with the
largest cluster being the CRF07_BC molecular cluster comprising 148
node values. Transmitted drug-resistance (TDR) mutations were found in
4.34% of the cases, with 1.79% associated with protease inhibitors
(PIs), 0.51% with nucleoside reverse transcriptase inhibitors (NRTIs),
and 2.55% with non-nucleoside reverse transcriptase inhibitors
(NNRTIs). Statistical analysis indicated a higher enrollment rate among
infected individuals with the CRF07_BC subtype, those identifying with
same-sex sexual roles as “vers,” and individuals with higher education
levels. This suggests the need for strengthened investigation and
intervention in this population to prevent the formation of larger
transmission clusters. Furthermore, continuous monitoring of the HIV-1
molecular dynamics network is necessary to promptly and accurately track
changes in molecular epidemic characteristics.