Objectives This investigation sought to characterise risk factors associated with acquisition of traditional and emerging agents of sexually transmitted infection (STI) in a cohort of young men who have sex with men and transgender women.

Methods 917 participants provided urine and rectal swab submissions assessed by transcription-mediated amplification (TMA)-based assays for Chlamydia trachomatis and Neisseria gonorrhoeae and by off-label TMA-based Trichomonas vaginalis and Mycoplasma genitalium testing. A subset provided specimens at 6-month and 12-month follow-up visits.

Results Prevalence of M. genitalium from rectal and urine specimens (21.7% and 8.9%, respectively) exceeded that of C. trachomatis (8.8% and 1.6%) and other STI agents. Black participants yielded higher prevalence of M. genitalium (30.6%) than non-black participants (17.0%; χ²=22.39; p<0.0001). M. genitalium prevalence from rectal specimens was 41.5% in HIV-positive participants vs 16.3% in HIV-negative participants (χ²=57.72; p<0.0001). Participant age, gender identity, condomless insertive anal/vaginal sexual practice and condomless receptive anal sexual practice were not associated with rectal C. trachomatis (p≥0.10), N. gonorrhoeae (p≥0.29), T. vaginalis (p≥0.18) or M. genitalium (p≥0.20) detection. While prevalence of T. vaginalis was calculated at ≤1.0%, baseline rectal and urine screening status was predictive of detection/non-detection at follow-up. A non-reactive M. genitalium baseline rectal or urine screening result was less predictive of non-reactive follow-up versus C. trachomatis, N. gonorrhoeae and T. vaginalis.

Conclusions Rectal M. genitalium detection is associated with black race and HIV seropositivity. Baseline M. genitalium infection influences subsequent detection of the organism.