Impact of Sexual Positioning on Stage of Syphilis at Diagnosis Among Men Who Have Sex With Men.

Abstract

Background: Men who have sex with men (MSM) have a disproportionately high syphilis burden. As anal ulcers are less visible than penile ulcers, we examined whether MSM practicing receptive or versatile versus insertive anal intercourse were more likely to be diagnosed at a later syphilis stage.

Methods: Using cross-sectional data from MSM enrolled in the Network Epidemiology of Syphilis Transmission study, we evaluated the associations between sexual positioning (exclusive bottom, versatile bottom, or versatile vs exclusive top or versatile top) and 3 outcomes: (1) syphilis stage diagnosed at baseline (secondary or latent vs primary), (2) lifetime history of syphilis, and (3) history of syphilis in the past 12 months.

Results: Overall, 655 MSM enrolled in Network Epidemiology of Syphilis Transmission; 599 had complete data on sexual positioning and syphilis stage at baseline. Of these, 57 had syphilis at baseline (Analysis 1), 506 had complete data on lifetime history of syphilis (Analysis 2), and 377 had complete data on history of syphilis in the past 12 months (Analysis 3). Among MSM with syphilis at baseline, those who practiced receptive or versatile versus insertive anal intercourse had 13 (95% confidence interval = 1.4-123) times the odds of being diagnosed with secondary or latent stage syphilis. Sexual positioning was not associated with syphilis history in the lifetime or past 12 months.

Conclusions: These findings suggest that differences in sexual positioning may influence the stage at which syphilis is diagnosed among MSM. Further research in larger samples is needed to better understand these differences and their underlying mechanisms and to assess potential implications for clinical detection and diagnosis.