The Infection Patterns And Molecular Epidemiological Study Among Heterosexually Transmitted HIV Population In Jiangsu Province

Backgrouds and ObjectivesIn recent years,more than 60% of the newly reported cases of HIV infection were caused by heterosexual transmission in China.Heterosexual transmission has become the main mode of transmission of HIV/AIDS epidemic in China.As an important bridge for the spreading of HIV/AIDS from various high-risk groups into the general population,heterosexual transmission is bound to cause a more severe HIV/AIDS epidemic.It is the key to take effective measures to prevent the HIV infection and transmission via heterosexual contact to deeply understand the composition and distribution characteristics of heterosexual transmission of HIV.Meanwhile,molecular epidemiology was used to analyze the genotypes and its distribution characteristics of HIV-strains prevalent in this population,it can help us to better understand the spread of HIV and its epidemic trend and to provide theoretical data support for targeted prevention and intervention in heterosexually transmitted population.Methods1.The subjects are HIV/AIDS cases reported in the Integrated Data Information system for AIDS Prevention and Treatment,which are transmitted through heterosexual transmission routes,328 patients with HIV/AIDS in routine CD4 follow-up cohort in Jiangsu Province from May to August 2017.A cross-sectional retrospective survey was used to conduct a questionnaire survey after obtaining the informed consent of the subjects.The contents of this survey mainly include: social demographic characteristics,history of exposure to past high-risk behaviors,and heterosexual transmission of HIV?including marital transmission,non-marital non-commercial sexual transmission and commercial sexual transmission?.The composition and distribution characteristics of infection patterns among heterosexually transmitted population was known by analyzing questionnaire data.2.The whole blood samples were collected and the plasma and blood cells were isolated.The PCR amplification and sequencing of gag and env gene fragments were performed by HIV-1 virus nucleic acid,and then the molecular epidemiology of HIV-1 was carried out.Using MEGA 7.0 software to compare the reference sequences with the acquired sequences from successful amplified samples in this study,the phylogenetic trees were constructed by using the Neighbor-Joining method to determine the genotyping of HIV-1 that epidemic in heterosexually transmitted popualtion.The distribution characteristics of different HIV-1 genotype in heterosexuals were further analyzed with cross-sectional investigation data.3.Statistical analysis: The Excel database was set up after the data of questionnaire survey and laboratory analysis were sorted out,and the statistical analysis was carried out by using the software of SPSS version 20.0 or SAS version 9.3.Selected different descriptive indicators according to the type of variable.Statistical analysis of infection patterns in heterosexuals and distributions of prevalent HIV-1 strains by different statistical methods.The generalized multivariate logistic regression was used to fit the generalized multivariate logit model,and the association between social demographic information and different infection patterns in heterosexuals was further analyzed,P<0.05 was considered to have statistically significant differences.Results1.Of the 328 recruited subjects,301?91.8%,301/328?cases were included in this stufy,most of them were considered to be transmitted by heterosexual contact.Most of them were male,accounting for 71.4%?215/301?,and the ratio of male to female was 2.5: 1.The minimum age was 18 years old,the maximum was 76 years old,and the median age was 42 years old.Marital status was mainly in marriage,accounting for 59.4%?179/301?.84.4%?254/301?of the respondents were the local census register population.The education level was mainly junior high school,accounting for 48.8%?147/301?.The living conditions were mainly cohabitation with the opposite sex and living alone,accounting for 49.8%?150/301?and 41.2%?124/301?,respectively.Those with full-time jobs accounted for 46.2%?137/ 301?,farmers or migrant workers accounted for 13.6%?41/301?,and retired or unemployed workers accounted for 24.9%?75/301?.2.Among 301 HIV/AIDS cases infected by heterosexual transmission,22.9%?69/301?were reported to be transmitted HIV by marital transmission,28.6%?86/301?by non-marital and non-commercial sex contact,48.5%?146/301?by commercial sex contact.Furthermore,the distribution of different HIV infection patterns were also not identical among different sex,residence,age,marital status,education level,working condition,monthly income level and the number of heterosexual partners?P<0.05?.3.The results of disordered multi-classification logistic regression analysis showed that compared with marital transmission of HIV,male?OR=3.86,95%CI: 1.28-11.59?,unmarried or divorced?OR=10.14,95%CI:2.29-35.19?,and heterosexual partners with more than 2 persons?OR=7.17,95%CI: 1.86-27.60?were associated with more non-marital non-commercial sexual transmission.Those with a monthly income below 1000 yuan?OR=0.03,95%CI: 0.00-0.63?were associated with less non-marriage and non-commercial transmission.Male?OR=33.89,95%CI: 11.34-133.37?,farmers or migrant workers?OR=8.75,95%CI: 1.37-55.76?,retired or unemployed workers?OR=6.06,95%CI: 1.22-30.09?,and heterosexual partners with more than 2 persons?OR=58.48,95%CI:14.75-231.78?were associated with more commercial transmission.4.Finally,a total of 262 subjects were amplified and genotyped successfully based on gag and env gene fragments analysis.CRF01_AE?45.4%,119/262?,CRF07_BC?21.4%,56/262?,subtype B?12.6%,33/262?,CRF08_BC?11.1%,29/262?were the major HIV-1 subtype strains circulating in heterosexually transmitted population,followed by CRF68₀1B?2.7%,7/262?,subtype C?1.9%,5/262?,CRF02_AG?0.4%,1/262?,CRF55₀1B?0.4%,1/262?and sub-subtype A6?0.4%,1/262?.In addition,3.8%?10/262?of sequences were the unidentified HIV-1 URFs.5.Various HIV-1 subtypes among the different HIV confirmation year,genders,occupation and regions have statistically significant differences?P<0.05?.A relatively high prevalence of CRF07_BC was found in female population.Among the HIV confirmed cases before 2008,subtype B was the most prevalent strain,accounting for 33.3%,while CRF01_AE became the most circulating strain after 2012,accounting for 52.0%.The prevalence of subtype B and CRF08_BC have decreased over time,but the prevalence of subtype CRF01_AE has gradually increased.In different occupations,a relatively low prevalence of subtypes B and CRF08_BC were found in farmers or migrant workers.In different investigation areas,CRF01_AE,subtype B and CRF08_BC were predominant HIV-1 strains circulating in South Jiangsu,accounting for about 80%,while around 70% of subjects were infected with CRF01_AE and CRF07_BC subtypes in Central and North Jiangsu.Conclusions1.HIV infection through extra-marital heterosexual contact is currently the most important manifestation of heterosexual transmission of HIV/AIDS in Jiangsu Province,and it is mainly commercial heterosexual transmission.1.In different heterosexually transmitted popualtions,the infection patterns have significant differences,suggesting that relevant agencies should develop and implement control strategies that are consistent with local HIV/AIDS epidemic characteristics and targeted prevention are particularly necessary.2.The epidemic HIV-1 subtypes among heterosexually transmitted population in Jiangsu Province are complex and diverse,and the circulating recombinant HIV-1 strains are increasing.There are also some differences in the distribution of subtypes of virous HIV-1 strains in different characteristic populations.Various HIV-1 subtypes exist in heterosexuals implies that HIV-1 is intermixing and recombinating quickly through heterosexual transmission in Jiangsu Province.In order to control the emergence of new HIV-1 recombinant strains,we should continue to strengthen the monitoring of HIV-1 molecular epidemiological study,grasp the situation of HIV-1 gene mutation and recombination and its epidemic trends,so that provide a better theoretical basis for the formulation of relevant preventive intervention measures.