Analysis On The Viral Transmitted Chain Among The Elderly Hiv Infected Individuals In Yongding District,hunan Province

ObjectiveTo investigate the characteristics of the transmittedchain among the elderly HIV-1 infected individuals in Yongding District,and find the patchy distribution of epidemic situation.To establish an accurate methodology for the detection of epidemic focus and the guidance for epidemic precise positioning,and more effective intervention measurescan be provided.Methods All the elderly HIV-1 Infected individuals in Yongding District during 2013-2016 were recruited.The plasma samples were collected and the pol region were amplified by In house method.After two rounds of PCR,the product was confirmed by 1% agarose gel electrophoresis,and then the gene was sequenced.The sequences of the transmitted chain were identified by the Phylogenetic trees.Meanwhile,the information of their demography,behavior,sociology were obtained by a face to face interview.The patchy distribution of epidemic situation and the transmittedchain among the local elderly HIV-1 Infected individuals was confirmed by the results of molecularbiology and epidemiological investigation.ResultsIn our study,a total of 57 valid questionnaires were collected.Among them,the male was 73.68%(42/57),commonly from rural areas(56.14%,32/57).The majority were married(50.87%,29/57),and primary school and below(54.39%,31/57).The transmission routes among the elderly HIV-1 Infected individuals,the vast majority of them became infected through unmarried heterosexual contact(64.91%,37/57),andintrafamilial transmission(22.81%,13/57).Little of the remaining cases were related to Male-to-male sexual(10.53%,6/57).The main motivator for participants to engage in visiting unlicensed prostitutes was the unfulfilled sexual desires within marriage.Visiting prostitute with peer,no condom,aphrodisiac using were considered commom contributing factors for engaging in sexual risk behaviors.In addition,compared with the heterosexual participants,older men who have sex with man are likely to use aphrodisiac(66.67%,4/6).This study included a total of 49 HIV-1 valid sequences,which were isolated from a total of 57 newly diagnosed the elderly HIV-1 Infected.The viral genotypes distributionamong the elderly HIV-1 Infected was as follows: 35 subtype B(71.43%,35/49),8 subtype CRF01_AE(16.33%,8/49),6 subtype CRF07_BC(12.24%,6/49).A Bayesian phylogenetic tree was reconstructed with 49 sequences.The tree demonstrated 49 sequences were separated into 10 highly significant transmission clusters:7 clusters among subtype B,2 clusters among subtype CRF01_AE,1 clusters among subtype CRF07_BC.In each cluster,the genetic distance is significantly less than the average genetic distance of each subtype strain.The Bayesian phylogenetic analysis revealed a close genetic relationship among the interior of cluster,showing a high degree of aggregation and homology within a small range.On the basis of epidemiology and the Bayesian phylogeny,We revealed 2 epidemic Focus named A and B.It indicates that the local elderly HIV-Infected individuals have a high level of homology between geographical position and behavior,and showing a significantly patchy distributions.ConclusionIn our study,the results indicated that the prevalence of HIV-1 among the elderly showed a significantly patchy distributions.The predominant strain is subtype B,and virals can be infected each other within a small range.Visiting prostitute is the main cause of HIV-1 infection,followed by intrafamilial transmission.There is a certain number of elderly MSM population,suggesting that we should pay attention to this special group.