Background:
MSM continue to be at increased risk for HIV infection and other STDs, which cause morbidity and potentiate HIV spread. Screening for asymptomatic STDs can assist clinicians and public health officials in planning cost-effective prevention interventions.

Objective:
The purpose of this project was to determine the prevalence of asymptomatic STDs among Boston area MSM who had been sexually active (oral and/or anal sex) with another male within the past year using nucleic acid amplification testing (NAAT).

Method:
During March 2007, all sexually active asymptomatic MSM in care at a Boston community health center (n = 114) were offered testing for gonorrhea (GC) and chlamydia (CT) by the BD ProbeTec at the MA state lab. Medical records were analyzed and linked to prevalence monitoring results.

Result:
Eleven-percent of the sample tested positive for GC or CT, with positivity rates of 6.1% for rectal CT, 2.6 % for urethral CT, 1.7% for rectal GC and 1% for urethral GC. There were no demographic predictors of who was most likely to have an STD, but individuals who had a prior STD history were more likely to have a new one diagnosed in this study (OR = 3.69; P < 0.02). Although there were no significant psychosocial differences observed between MSM with or without an incident STD, 19% of the cohort had a substance use disorder (SUD), which was correlated with depression (r = 0.26; P < 0.01) and being HIV-infected (OR = 3.29; P < 0.01).

Conclusion:
Screening asymptomatic MSM using NAAT revealed a substantial STD burden that might not have been diagnosed using traditional assays in a group of MSM reporting increased behavioral risks for further HIV/STD transmission and acquisition.

Implications:
These data are critical for the design of effective public health interventions for this population.