Risk Factors for HIV Diagnosis Among Men Who Have Sex with Men: Results of a Case-Control Study in One Sample of Eastern China.

Substantial increases in human immunodeficiency virus (HIV) have been reported worldwide in recent years, particularly among men who have sex with men (MSM). We conducted a matched case-control study to examine the factors associated with HIV diagnosis among MSM in one sample of eastern China. Between February 2012 and December 2014, we used surveillance records to identify MSM diagnosed with HIV (case participants); we also recruited MSM who did not have HIV (controls) and then matched them (2:1) with control cases in terms of age (±3 years). Multivariate logistic regression models were used to assess the factors associated with HIV diagnosis. According to a multivariate analysis using logistic regression model involving 101 cases and 202 matched controls, a lack of comprehensive knowledge of HIV (adjusted odds ratio [OR] = 0.40; 95% confidence interval [CI] = 0.18, 0.89), a monthly income of ≥4,000 RMB (adjusted OR = 2.99; 95% CI = 1.45, 6.16), having at least two male sexual partners in the past 6 months (adjusted OR = 2.85; 95% CI = 1.28, 6.31), participating in at least four anal sex experiences with a man in the past month (adjusted OR = 3.56; 95% CI = 1.64, 7.73), and having a current syphilis infection (adjusted OR = 3.30; 95% CI = 1.06, 10.25) were associated with an increased risk for HIV diagnosis. MSM with a comprehensive knowledge of HIV were at reduced risk of HIV diagnosis, whereas those with more male sexual partners, more male anal sexual experiences (including receptive or/and insertive anal intercourse, rimming, and fisting), and a current syphilis infection were at increased risk of HIV diagnosis. Focus on protection and safer sex behaviors during male sexual activity (i.e., consistent condom use, pre-exposure prophylaxis, closed sexual networks among MSM) would likely be effective for reducing the HIV transmission rate.