The Behavioral Intervention And HIV Incidence Cohort Studies Among Men Who Have Sex With Men In Nanjing

Objective: To study the demographic and sexual behaviors among MSM (men who have sex with men) in Nanjing through epidemiology survey; to examine the effectiveness of behavioral intervention combined with VCT; to estimate the HIV incidence among a MSM cohort, as well as to examine the effect of loss to follow up on the estimation of HIV incidence.Method: A behavioral and serological survey was carried out among 767 MSM in Nanjing from May 2008 and May 2009. Data on demographics, awareness of AIDS and behavioral characteristics were collected. A behavioral intervention combined with VCT was conducted in 2008, 2009 and 2010 respectively, the change in knowledge about AIDS, sexual behavior was compared before and after the intervention. A cohort study started in May 2008, with regular follow-ups every 6 months until May 2010. Database was constructed using EpiData 3.0 software with double data entryentered. Data were later exported to Microsoft Excel for data cleaning. All descriptive and analytical analysis were done using SPSS16.0 software.Results: (1) MSM in Nanjing were mainly aged between 20-40 years old (85.3%), with higher proportions of being single (80.1%), with junior college education (70.5%), and with a monthly income of 1,001-3,000 RMB (55.2%). The awareness of AIDS is 96.2%. Up to 36.9% of interviewees have multiple sex partners within the recent half a year. The rate of unprotected anal sex (UAI) is 55.3%. 20.6% of participants have sex with female partners, but only 27.9% of them use condom each time. (2) Behavioral intervention combined withVCT shows that the awareness of AIDS is 97.6%, 98.0% and 98.8% among 606 interviewees at baseline, 616 at mid-term and 400 at the end respectively, without a significant difference. The rate of unprotected anal sex (UAI) in the past 6 months decreased significantly from 58.1% at baseline to 43.2% at the mid-term and 49.2% at the end respectively (p<0.05). During the last anal sex, 42.2% interviewees did not use condom at baseline while this percentage decreased significantly to 32.5% at mid-term and 36% at the end. In the past 6 months, the proportion of MSM with more than two sex partners has been decreased from 20.8% to 15.5% (p<0.05) and those who have sex with female have decreased from 20.8% at baseline to 15.6% at mid-term and 15.5% at the end. The incidence of syphilis also showed a decrease from 11.4% to 7.5% and 7.8%.(3)The overall follow-up rate of the MSM cohort in the past two years is 44.8%, with the HIV incidence of 3.5/100 person-years (PY) (95%CI : 1.8-8.9/100 PY). Those lost to follow-up at 6 months had higher risk behavior than those retained, which may result in the underestimation of HIV incidence. However there were no significant difference in HIV-related behavior between those lost to follow up and those retained in the subsequent follow-up visits.Conclusions: (1)The high-risk behavioral status of MSM in Nanjing cannot be neglected. Intensified publicity and behavior intervention are urgently required to increase self-protection and self test consciousness, to promote early detection of HIV infections, prevent the spread from HIV cases to othersand to slow down the increasing trend ;(2)Through two years behavioral intervention combined with VCT, the rates of high risk behavior and the prevalence of current syphilis of MSM were significant decreased; (3)cohort study of MSM in Nanjing shows that those loss-to-follow-up have higher risk behaviors at 6 months follow-up. The HIV incidence may be under-estimated according to the information obtained from the current interviews.