HIV/STI Infection, Risk Behavior And Sexual Networks Among Men Who Have Sex With Men In Taizhou City, Zhejiang Province

Objectives:To survey the human immunodeficiency virus/sexually transmitted infections (HIV/STI),risk behavior,social/sexual network and population mobility of men who have sex with men(MSM) in Taizhou City,Zhejiang province.Methods:A cross-sectional study was conducted under a venue-based sampling in 8 local MSM gathering places in Taizhou City.A structural questionnaire,group interview and observation on internet were applied for investigation.Blood samples were collected from those MSM who accepted free and confidential HIV/STI assays and tested for HIV and HSV-2 antibodies by ELISA.Sera tested HIV positive were then certified by western blot.TPPA was applied to test the syphilis infection status. Descriptive and analytical statistics were applied to analyze the data of structural questionnaire for behavior of MSM.Social network analysis and data mining were practiced to explore the structure of relationships in different levels,including social and sexual network among MSM in the micro-level,interrelationship among places of MSM gathering in the mezzo-level,and the mobility of MSM among cities in the area of Yangtze river delta,i.e.,in the macro-level.Structural questionnaire was also applied,with observations on internet,to investigate how MSM in Taizhou utilize the internet to make friends and transfer information.In a MSM party,a letter transferring game was conducted to simulate the information transmission network among these MSM.In 3 male-to-male sex worker(MSW) clubs and 1 MSM bathroom,group interviews were held to get information about the behavior and mobility of MSW in Taizhou as a supplement of structural questionnaire.Results:251 MSM participated in the study,and among which,196 MSM answered the questionnaire and took the free and confidential HIV/STI test,37 MSM only wished to answer the questionnaire but did not have the blood test,and 45 MSM only took the blood test but refused to answer the questionnaire.Finally,206 effective questionnaires and 214 blood samples were collected. For the 206 MSM answered questionnaire,157 of them were general MSM,and 49 of theme were MSW.43.7%(86/197) of these MSM had 2 or more female sex partners.42.9%(85/198) of them had 2～5 male anal intercourse partners,and 49.5% (98/198) of them have 5 or more.Only 40.1%(77/192) of them used condom in every anal intercourses.37.3%(76/204) had bought sex from female sex worker, 31.8(64/201) of them had bought from male-to-male sex worker,and 25.1%(48/191) of them had sold sex to another man.Blood test showed that 7.0%(15/214) of HIV of these MSM were certified positive of HIV infection,while 10.8%(23/212) were found HSV-2 antibody positive,and 23.1%(49/212) were TPPA positive.127 MSM reported their egocentric networks of recognition and sexual relationship.The average size of their recognition and sexual networks were 8.14±3.15 and 8.14±3.15,respectively.Size stratified social network measurements, including degree,density,information centrality and betweenness centrality were calculated to describe the network structure.Also,some typical cases of networks were depicted.The study of MSM mobility was conducted with a multilevel model using social network analysis and data mining.In the urban area level,MSM gathering places were tightly interrelated,and a gay Bar L were found in the relative central position of these places.In the municipal level,MSM's activities mostly aggregated in Jiaojiang, Luqiao and Huangyan District,and these three districs were also in the center of counties network.In the level of Yangtze River delta,cities such as Hangzhou, Shanghai,Ningbo and Wenzhou were tightly linked with each other by floating MSM.In the study of information transmission among MSM in Taizhou,the result of internet observation and questionnaire investigation showed that local MSM were tightly connected with MSM websites and QQ groups(online chat group with a software called OICQ of Shenzhen Tencent Company,China),and the central websites and QQ groups were identified.In the QQ user network connected by 13 major MSM QQ groups in Taizhou,the average distance between every two users was 1.861.In the letter transmission game,2 components of local MSM friendship network were identified.The size of component 1 was 72,the density was 0.0178, while the size of component 2 was 28,and the density was 0.0463. The group interview showed that local MSW generally had acknowledged the HIV/STI infection risk of commercial sex work,and they were willing to accept health intervention.Conclusions:Risk behaviors,such as multiple sex partners,low proportion of condom use and commercial sex deals,both heterosexual and homosexual,were common among MSM in Taizhou.Prevalence of HIV/STI among them was relatively high,and comprehensive behavior intervention should be initialized as soon as possible. Combined with the multilevel investigations,a comprehensive model for behavior of MSM in Taizhou,and then,a referable framework for structural intervention,was proposed.