A Study On Unprotected Anal Intercourse And Associated Factors Among Men Who Have Sex With Men In Tianjin

Objective:MSM is the men who reports having anal and/or oral sex with men.The purpose of this study was to understand the changes of AIDS knowledge,history of STD diagnosis and treatment,prevalence of anal intercourse,condom use among different partners,commercial sexual behavior,recreational drug use and traditional drugs among MSM cohorts.Meanwhile,exploring the prevalence of unprotected anal intercourse among all homosexual partners,regular partners and casual partners and assessing the correlates of unprotected anal intercourse among different types of partners are other purpose of this study.According to the above correlates,the HIV new infection between the above groups were compared to explore new ways for HIV prevention and control in Tianjin.Methods:This study was based on the research of China center For Disease Control and Prevention,it was an open cohort study from April 2013 to September 2018,it took 5 years and 6 mouths to complete one baseline and ten follow-ups.Recruitment information was published on MSM crowds gathering places(such as bars,clubs,baths,STD clinics)and Internet App(Wechat,QQ,Blude,etc.)by Tianjin volunteer team.Men who were aged 16 years or older,living in Tianjin,willing and able to provide written informed consent were eligible to participate in the cohort.We conducted a longitudinal analysis that included MSM who were enrolled from 2013 to 2018 and contributed to at least one follow-up visit.At enrollment,all MSM were screened for HIV-1,completed sexual behavior questionnaires about the previous six months using an Independently Developed Fingerprint System(IDFS)which was developed by ‘Shenlan' to collect fingerprint information of forefinger of both hands.After the baseline visit,participants were expected to return for a follow-up visit every six months.At each of these follow-up visits,participants logged in an IDFS to complete questionnaire.Health education was conducted among MSM cohorts.It included HIV infection risk assessment,HIV infection risk warning education,STD referral treatment,and the harm of synthetic drug abuse.HIV-negative participants underwent HIV testing and counseling in an MSM-friendly setting,with HIV-positive referred for care,support,and treatment services.Questionnaires of IDFS were exported regularly according to Tianjin CDC,and data cleaning and analysis were carried out by SAS 9.4 statistical software.First,descriptive statistics for all variables were obtained.Quantitative data were described by M±SD,qualitative data were described by frequency distribution.In accordance with our study objective,we performed generalized estimation equation(GEE)analyses to identify potential predictors of UAI with difference types partners.we used generalized estimation equation to obtain the adjusted odd ratios(a OR).At the same time,new HIV incidence was calculated to understand the new infection rate in Tianjin.Statistical significance was evaluated using a two-sided p-value of 5%.All the analyses were performed with SAS 9.4.Results:1)From April 2013 to September 2018,we enrolled 2380 MSM into the study,including 1404 who at least completed one follow-up visit,933 participates completed two follow-up visits,669 participates completed three follow-up visits and 465 participates completed four or more follow-up visits.It was followed for 3091.1 PY,with 2.20 year per men.With health education and intervention conducted,the awareness rate of AIDs knowledge for MSM increased(Trend ?~2=92.16,P<0.001)and the rate of history of STD diagnosis and treatment decreased(Trend ?~2=4.38,P=0.036).With the increase of follow-up visits,the incidence of anal intercourse with homosexual partners(Trend ?~2=44.76,P<0.001),regular partners(Trend ?~2=10.55,P=0.001)and casual partners(Trend ?~2=8.79,P=0.003)increased.The condom use in the last anal intercourse with homosexual partners(Trend ?~2=171.23,P<0.001),regular partners(Trend ?~2=66.17,P<0.001)and casual partners(Trend ?~2=112.56,P<0.001)increased.In previous six months,the condom use in anal intercourse increased too,after three follow-up visits,the condom use decreased.In addition,when comparing the condom use of several types of partners,it was found that commercial sexual condom use rate was the highest.With the increase of follow-up visits,the self-reported use of traditional drugs is not high,while the use of recreational drug increased(Trend ?~2=37.06,P<0.001),and the proportion of Internet samples sources increased(Trend?~2=22.46,P<0.001).2)To explore all the same-sex partners in MSM population,it concluded that AIDS knowledge(a OR=0.146),unmarried(a OR=0.655),highly educated(a OR=0.766),commercial sexual behavior(a OR=0.693),age range from 25 to 45(a OR=0.712)and age above 45(a OR=0.518)were the protective factor for UAI,while internet sample source(a OR=1.238),history of STD diagnosis and treatment(a OR=1.376),and traditional drug(a OR=2.934)were the risk factors for UAI.The associated factors were slightly different between regular partners and casual partners.Knowledge of AIDS,Unmarried,Internet sample sources and Low age were common influencing factors,while the use of recreational drug use(a OR=1.403)was only significant in regular partners.In casual partners,the traditional drug use(a OR=3.278)and STD diagnosis and treatment(a OR=1.447)were unique risk factors.3)A total of 1 404 person were followed up in this cohort,69 new cases of HIV infection were reported,and the cumulative observational person-years on cohort follow-up was 3091.10 person-year.With the positive conversion rate of HIV was 4.91%(69/1404),and the positive conversion density was 2.23 per 100 person-years.According to the above AOR of unprotected anal sex,the positive conversion rate and positive conversion density of HIV antibodies among these subgroups were calculated respectively.Among subgroup of AIDS knowledge,the positive conversion rate of HIV was 5.28% and the positive conversion density was 2.38 per 100 person-years.Among subgroup of unmarried,the positive conversion rate of HIV was 5.00% and the positive conversion density was 2.37 per 100 person-years.Among subgroup of highly educated,the positive conversion rate of HIV was 4.47% and the positive conversion density was 2.23 per 100 person-years.Among subgroup of college and above,the positive conversion rate of HIV was 5.08% and the positive conversion density was 2.33 per 100 person-years.Among subgroup of age below 25,the positive conversion rate of HIV was 5.56% and the positive conversion density was 2.59 per 100 person-years.Among subgroup of commercial sexual behavior,the positive conversion rate of HIV was 3.90% and the positive conversion density was 1.64 per 100 person-years.Among subgroup of recreational use,the positive conversion rate of HIV was 4.50% and the positive conversion density was 2.39 per 100 person-years.Among the group with history of STD diagnosis and treatment,the positive conversion rate of HIV was 7.69% and the positive conversion density was 3.45 per 100 person-years.Among group of internet sample source,the positive conversion rate of HIV was 4.47% and the positive conversion density of HIV was 2.23 per 100 person-years.A total of 1 275 syphilis-negetive person were followed up in this cohort,259 new cases of syphilis infection were reported,and the cumulative observational person-years on cohort follow-up was 2445.14 person-year.With the positive conversion rate of syphilis was 20.3%(259/1275),and the positive conversion density was 10.59 per 100 person-years.Conclusions:1)The awareness rate of AIDS knowledge among MSM population in Tianjin is generally high,showing a "ceiling effect".However,the incidence of high-risk sexual behavior is high,The propaganda intervention in the cohort plays a role on reducing high-risk sexual behavior,however,the effect is not lasting.More effective intervention is urgently needed.2)In this cohort,propaganda intervention,condom distribution and other measures were applied,which partly reduces the incidence of new HIV infection,but the effect on new syphilis infection is not well.Epidemic of HIV in Tianjin is low,but positive anti-HIV antibody in the sub-group of low age,recretional drug use and history of STD diagnosis and treatment is higher.We should pay more attention to these subgroups.3)Unprotected Anal Intercourse is common in MSM population,and associated factors affecting UAI are different among different types of sexual partners.Targeted measures should be taken to reduce rate of UAI,thus depressing the epidemic of HIV and other sexually transmitted diseases.