Multifactorial Correlates of Incident Bacterial Sexually Transmitted Infections among Black Men Who Have Sex with Men Recruited in 6 US Cities (HIV Prevention Trials Network 061)

Background Black men who have sex with men are at a disproportionate risk for sexually transmitted infections (STI). Understanding the drivers of those disparities can lead to culturally tailored interventions. We aimed to characterize the incidence and correlates of STI among Black individuals from HIV Prevention Trials Network 061, a multicity cohort study conducted from 2009 to 2011 in the United States. Methods We used Cox proportional hazards regression to estimate adjusted hazard ratios (aHRs) accounting for within-participant correlation over multiple follow-up visits (enrollment, 6 and 12 months). We examined correlates of incident rectal and urethral STI as well as incident syphilis. Results Among 1522 individuals, the incidences of urethral and rectal Neisseria gonorrhoeae infection were 1.0 (95% confidence interval, 0.6-1.8) and 4.6 (95% CI, 3.5-6.3) cases per 100 person-years, respectively. The incidences of urethral and rectal Chlamydia trachomatis infection were 2.5 (95% CI, 1.7-3.6) and 2.5 (95% CI, 1.7-3.7) cases per 100 person-years, respectively. The incidence of syphilis was 3.6 (95% CI, 2.7-4.9) cases per 100 person-years. Younger age was associated with increased odds of incident urethral (aHR, 5.1; 95% CI, 2.3-11.1) and rectal (aHR, 2.6; 95% CI, 1.6-4.3) STI. Diagnosis of a rectal STI at baseline (aHR, 2.3; 95% CI, 1.1-4.0) and use of saliva as lubricant (aHR, 1.7; 95% CI, 1.1-2.8) were associated with incident rectal STI. Diagnosis of syphilis at baseline was associated with incident syphilis during follow-up (aHR, 5.6; 95% CI, 2.5-12.2). Conclusions Younger participants had the highest STI incidence. Use of saliva as lubricant may be a driver of rectal infection, which deserves further study.