Characteristics of the molecular transmission network in newly confirmed human immunodeficiency virus type 1 infected cases from 2018 to 2019 in Shaoxing City, Zhejiang Province / 中华传染病杂志

ABSTRACT

Objective:To analyze the characteristics of the molecular transmission network of newly-diagnosed human immunodeficiency virus type 1 (HIV-1) infected individuals in Shaoxing City, Zhejiang Province, and to provide evidence for epidemic trend and prevention.Methods:The plasma samples from 423 antiretroviral-naive HIV-1/acquired immunodeficiency syndrome patients from August 2018 to December 2019 were collected, and the pol gene fragments of HIV-1 from 375 samples were amplified by reverse transcription polymerase chain reaction (PCR) and nested PCR. The phylogenetic tree was constructed to analyze the molecular transmission network for subtypes and different gene distances by MEGA 6.0 software, HyPhy software and Cytoscape 3.7.2. Mutations on drug resistance was analyzed by online software tool of the HIV drug resistance database of Stanford University. Results:Eight subtypes were found in the 375 samples. Circulating recombinant form (CRF)07_BC(215/375, 57.33%) and CRF01_AE(103/375, 27.47%) were the major subtypes, followed by CRF85_BC, CRF55_01B, B, C, and CRF01_AE/B subtypes. One hundred and ninety-four individuals (51.73%) were connected to the transmission network at 1.50% genetic distance with 24 clusters. One hundred and twenty-nine individuals (34.40%) were connected to the transmission network at 0.75% genetic distance with 30 clusters, and 35 elderly patients were clustered in CL1.Forty-two cases had surveillance drug resistance mutation (SDRM), the prevalence of transmitted drug resistance was 11.20%(42/375). Thirty-eight cases had the drug mutations to non-nucleoside reverse transcriptase inhibitor, including K103 N(32/375, 8.53%), K103 S(4/375, 1.07%), Y188 L(1/375, 0.27%) and G190 A(1/375, 0.27%); four cases had the mutations to protease inhibitor, including M46 I(3/375, 0.80%) and V82 A(1/375, 0.27%). The cluster C2 sequences carried a high proportion of resistant mutations (94.29%, 33/35). Conclusions:HIV-1 subtypes in Shaoxing City are diverse and the CRF07_BC subtype spreads rapidly. The elderly patients with drug resistance genes in cluster CL1 at 0.75% gene distance need to be intervened immediately to prevent the drug resistance virus spread.