Contribution of sexual practices (other than anal sex) to bacterial sexually transmitted infection transmission in men who have sex with men: a cross-sectional analysis using electronic health records

Objective We quantified the proportion of cases and risk of primary syphilis (PS), urethral chlamydia (UCT) and urethral gonorrhoea (UGC) attributable to sexual practices other than anal sex. Methods In this cross-sectional study, electronic records for men who have sex with men (MSM) who attended the Melbourne Sexual Health Centre between July 2002 (for PS) or January 2006 (for UCT and UGC) and October 2012, inclusive, were examined. Results There were 37 533 eligible consultations; 2374 (6%) of these reported no anal sex. There were 204 PS diagnoses, 673 UCT diagnoses, and 618 UGC diagnoses; 12 (6%), 16 (2%) and 44 (7%) cases, respectively, occurred in consultations where no anal sex was reported in the previous 3 months (PS, UGC) or twelve months (UCT). Among MSM reporting no anal sex, PS was diagnosed in 0.5 cases/100 consultations, UCT was diagnosed in 1.5 cases/100 tests for UCT and UGC was diagnosed in 14 cases/100 tests for UGC. UCT was significantly more common in MSM reporting anal sex (OR 2.18, 95% Cl 1.32 to 3.59, p=0.002), but PS (OR 1.07 95% Cl 0.6 to 1.93, p=0.82) and UGC (OR 1.28 95% Cl 0.92 to 1.79. p=0.14) were not. For MSM reporting anal sex, condom use was protective for all three infections (all p <= 0.03). Conclusions Our findings suggest that UCT uncommonly occurs from sexual practices other than anal sex; however, these practices contribute significantly to PS and UGC. Successful programmes to control PS and UGC will need strategies, such as frequent testing, in addition to promoting condom use.