Molecular network characteristics of newly reported HIV/AIDS cases in Lishui City,Zhejiang Province,from 2020 to 2022
Objective The study aimed to analyze the molecular network characteristics of newly reported HIV/AIDS cases in Lishui City from 2020 to 2022,in order to provide references for precision intervention.Methods A total of 385 blood samples were collected from newly reported and untreated HIV/AIDS patients from 2020 to 2022.The pol genes of the samples were amplified by reverse transcription and nested polymerase chain reaction,and then sequenced.A phylogenetic tree was constructed using MEGA 7.0 to analyze the subtypes.Cytoscape 3.9.0 was used to generate a molecular network for subtype transmission analysis factors affecting the network entry rate.Logistic regression model was employed to analyze factors associated with entering the network.Results Out of 385 specimens,366 pol gene sequences were successfully amplified.Eight subtypes and three circulating recombinant forms(CRFs)were identified.The dominant subtypes were CRF08_BC(37.98％),CRF01_AE(25.41％),and CRF07_BC(24.04％).With a genetic distance threshold of 1.2％,40 molecular clusters were formed,and 208 sequences entered the network,resulting in a network entry rate of 56.83％.Notably,six clusters contained individuals who were positive for HIV and identified as female sex workers.Within these six clusters,81.65％(89/109)of the patients had a genetic distance threshold ≤1.2％from positive female sex workers.Furthermore,seven molecular clusters with five or more nodes showed clear regional aggregation,primarily in County A.The largest cluster,consisting mainly of CRF08_BC,included 82 patients,66(82.50％)had a genetic distance threshold ≤1.2％from the two positive sex workers.The main characteristics of patients in this cluster included:male(81.71％),age ≥50 years old(85.37％),married(52.44％),education level of primary school or below(63.41％),current address in County A(91.46％),and a history of non-marital commercial heterosexual activity(75.61％).Among the 52 patients admitted to the cluster in 2021 and 2022,42(80.77％)were locally infected.Additionally,45(86.54％)were infected in 2020 or before,while only 4(7.69％)were infected in 2021 or later.Multi-factor logistic regression analysis revealed that the CRF08_BC subtype was more likely to enter the network compared to other subtypes(odds ratio=7.794,95％CI:4.212-14.421).Conclusions Lishui City exhibits diversified sources of HIV transmission,with evident and regional aggregation of transmission clusters.Female sex workers play a significant role in HIV transmission.The largest molecular transmission cluster,centered on prostitution and demonstrating regional clustering,is still expanding.However,this expansion is primarily driven by the identification of patients infected before 2020.These patients may have been infected for a long time before diagnosis,and they may have caused new transmissions.Moving forward,efforts should focus on strengthening the traceability of key clusters,promoting partner notification for identified cases,and implementing comprehensive interventions to address commercial heterosexual behavior.
HIV subtypemolecular transmission networkgenetic distance thresholdprecise intervention
NETL
NSTL
万方数据
