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Objective@#To investigate the molecular transmission network characteristics of HIV-1 among men who have sex with men (MSM) in Shaoxing City, Zhejiang Province, so as to provide insights into AIDS prevention and control among MSM.@*Methods@#Newly reported HIV/AIDS cases among MSM in Shaoxing City were selected from January 2021 to September 2023. Plasma samples before the antiviral treatment were collected. The HIV-1 pol gene was amplified using reverse transcription PCR and nested PCR to construct phylogenetic trees for gene subtype analysis. The HIV-TRACE method was used to construct a molecular transmission network with a genetic distance of 1.5% to analyze clustering and the characteristics of cases within molecular clusters.@*Results@#A total of 216 HIV/AIDS cases among MSM were included, and 179 qualified sequences were obtained. The predominant HIV-1 subtypes were CRF07_BC and CRF01_AE, with 95 and 66 cases, respectively. At 1.5% genetic distance, 20 molecular clusters were formed, with 61 nodes and 58 edges. A total of 61 sequences were connected to the transmission network (34.08%). HIV/AIDS cases among MSM from all the counties (cities, districts) in Shaoxing City were included in the network. There was the largest molecular cluster with ≥10 nodes, involving 12 cases from five counties (cities, districts), 3 medium-sized molecular clusters with 4 to 5 nodes, and the 16 small-sized molecular clusters with 2 or 3 nodes. Seven cases with high risk of transmission, each with ≥4 edges, were all CRF07_BC subtypes. Among them, two cases were from the large molecular cluster, and five cases were from the same molecular cluster composed of cases from Shengzhou City and Xinchang County.@*Conclusions@#The predominant HIV-1 subtypes among MSM in Shaoxing City were CRF07_BC and CRF01_AE. There was cross-regional HIV transmission, and potential transmission risk might exist in Shengzhou City and Xinchang County.
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ObjectiveThis study aimed to investigate the HIV genotypic subtypes and molecular transmission clusters among men who have sex with men （MSM） with newly reported HIV infections in Dehong Dai and Jingpo Autonomous Prefecture （Dehong Prefecture）， Yunnan Province， China， between 2010 and 2019. The study aimed to identify potential high-risk transmitters and provide reference data for screening， management， and intervention of infection sources. MethodsPlasma samples from newly reported HIV-positive MSM individuals in Dehong Prefecture between 2010 and 2019 were collected. The viral pol gene fragments were amplified， sequenced， and genotyped. Genetic distances （GD） between pairwise sequences were analyzed and calculated. MEGA 7.0 and Gephi were used for phylogenetic and molecular transmission network analysis. ResultsA total of 159 newly reported HIV infections among MSM were included in the study， with successful genotyping of 100 cases. Nine HIV-1 subtypes were identified， with the most prevalent being CRF01_AE subtype （52%）， followed by CRF07_BC subtype （31%）， CRF55_01B subtype （10%）， and others （7%）. Cluster analysis revealed a total network access rate of 67%， forming three transmission clusters. CRF01_AE subtype formed two transmission clusters with 38 and 3 infected individuals， while CRF07_BC subtypes formed one transmission cluster with 26 infected individuals. The transmission network within the CRF01_AE clusters exhibited a more complex relationship. Significant differences in educational level were observed between the two main transmission clusters. ConclusionThe predominant HIV subtypes among newly reported MSM cases in Dehong Prefecture between 2010 and 2019 were CRF01_AE and CRF07_BC. Significant cultural differences are observed between the main transmission clusters. Continued monitoring of genotypic subtypes and targeted interventions within transmission clusters are warranted.
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Objective:To investigate the molecular epidemiological characteristics of HIV-1 infection among men who have sex with men (MSM) in Jiaxing city, and provide methods and ideas for the prevention and control of HIV-1 infection.Methods:This study retrospectively collected the blood samples from all newly reported cases of HIV-1 infection among MSM without antiviral treatment from 2020 to 2022. HIV-1 pol genes in the blood samples were amplified and sequenced. MEGA v6.0 software was used to analyze nucleic acid sequences. A phylogenetic tree was constructed to analyze HIV-1 subtypes. The calibrated population resistance program (CPR) was used to detect drug-resistant mutations. After calculating the genetic distance between gene sequences, molecular transmission networks were constructed using Cytoscape v3.6.0 software. Results:A total of nine genetic subtypes were identified, with CRF07_BC (43.3%) and CRF01_AE (36.9%) accounting for the most. The recombinant forms that were not clustered with the reference subtype accounted for 5.0%. Drug-resistant mutations were identified in 21 cases (7.0%), and the mutation rates among strains of CRF07_BC and CRF01_AE subtypes were 8.2% and 7.8%, respectively. The detection rates of drug-resistant mutations to protease inhibitors, nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors were 1.7%, 0.7% and 4.7%, respectively. The optimal genetic distance threshold of the molecular network was 0.018. At this genetic distance, the molecular network access rate was 43.3%, and 38 molecular clusters (ranging from 2 to 26 nodes per cluster) were included. Cases with ≥6 homosexual partners and a degree value of ≥4 were more likely to access the active molecular cluster. The population of high-risk transmission cases with TNS>0.75 were mainly nonlocal residents and commercial service providers. The recombinant forms showed high similarity in sequences with the strains from other provinces.Conclusions:The distribution of HIV-1 subtypes in MSM in Jiaxing city was complex. Given the increasing detection rate of recombinant forms, the high transmission rate of drug-resistant mutations, and the active molecular clusters and high-risk transmission clusters mainly detected in nonlocal residents and commercial service providers, strengthened surveillance and intervention are needed.
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Objective:To understand the molecular transmission characteristics of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome(AIDS) patients in the mountainous area of southwest Zhejiang Province(Lishui city).Methods:A total of 147 blood samples were collected from newly-diagnosed HIV-1 infected who received no antiviral therapy, and pol gene was amplified, followed by sequencing. MEGA6.0 software was used to construct phylogenetic tree and determine gene subtypes. HIVDB online was used to analyze drug resistance mutation, then the pairwise genetic distance(GD) was calculated and the opitimal threshold of GD was selected, finally the molecular transmission network was constructed by Cytoscape3.7.0 software. Chi-square or Fisher′s exact probability method was used for statistical analysis. Results:A total of 134 sequences were obtained successfully, and nine subtypes were detected. The dominant subtypes were CRF08_BC (34.33%, 46/134), CRF01_AE (29.85%, 40/134) and CRF07_BC (23.88%, 32/134). It also found that age, registered residence, education level and transmission route had significant differences in distribution of subtypes ( P<0.05). Nineteen drug resistance individuals were found, and the total drug resistance rate was 14.18% (19/134). The HIV-1 molecular transmission network was plotted based on 1.2% GD threshold. A total of 15 transmission clusters (cluster size ranging from 2 to 29) were found. The network access rate was 49.25% (66/134), mainly including male (75.76%, 50/66), heterosexual (81.82%, 54/66) and patientsrinfected with CRF08_ BC (50.00%, 33/66). A transmission cluster including two cases of female sex workers and seven cases of drug resistance was identified, in which the average age of the patients was 57.21 years old and the average degree value was 22.7, and the cases were mainly infected through heterosexual contact (96.55%, 28/29). The highest homology of the sequences in the cluster was in Yunnan. Conclusions:The HIV-1 subtypes were diverse in the mountainous area of southwest Zhejiang Province(Lishui city). Drug resistant transmission had reached a moderate epidemic level. There were molecular transmission clusters with the aggregation characteristics of elderly clients in specific regions. It was urgent to formulate and implement precise intervention strategies to curb the spread of HIV.
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Objective@#Using field epidemiological investigation and molecular analysis to construct the molecular transmission network of human immunodeficiency virus/acquired immunodeficiency syndrome cases (HIV/AIDS) newly diagnosed in Huzhou in 2017, Zhejiang Province.@*Methods@#A total of 160 participants were obtained through a web-based system from Chinese Center for Disease Control and Prevention (CCDC) with the features of diagnosed in Huzhou in 2017 who also had been collected samples for the first follow-up. The basic information of demographic characteristics and risk factors was extracted from the website. RNA was extracted from plasma samples of untreated cases, followed by RT-PCR and nest-PCR for pol gene amplification, sequencing. Phylogenetic tree was constructed by MEGA software for HIV gene subtyping. TN93 model was used for calculating the distance between two sequences. Cytoscape software was used for drawing molecular transmission network. And then an epidemiological survey was conducted to cases in the primary cluster.@*Results@#A total of 138 sequenced individuals (86.3%) were acquired from 160 individuals. Among which, 123 (89.1%) were male. The highest proportion of subtype was CRF07_BC (60, 43.5%), followed by CRF01_AE (46, 33.3%), and with four cases of Unique Recombinant Form (URF, CRF01_AE and CRF07_BC) and one case of URF (subtype B and C). A total of 18 molecular clusters included 56 individuals (40.6%) were found in the transmission network under the optimal genetic distance threshold (1.0%). The clustering proportion of CRF07_BC (66.1%, 37 cases) was higher than that of CRF01_AE. There were 9 clusters formed among CRF07_BC, including 37 cases (accounting for 61.7%, 37/60). The primary transmission cluster contained 11 cases, among which 9 cases were transmitted by homosexual sex. The first time of the cases to have homosexual behavior is range from 2010 to 2016, whose media number (P25, P75) of partners was 6 (3.5, 8.5). Most of the cases come from Anhui Province and engaged in garment industry (5 cases), between which there were 8 cases used Blued software to seek for casual partners, 1 case seeking for casual partners in garden.@*Conclusion@#With CRF07_BC and CRF01_AE predominantly circulating, HIV genetic diversity had been noticed in this area. The primary cluster was consisted of high proportion of locally new infections, and a specific population aggregation in limited place existed.