Background Syphilis, chlamydia and gonorrhoea are increasingly common amongst Australian men who have sex with men (MSM). Our objective was to quantify the proportion of cases and risk of primary syphilis (PS), urethralchlamydia(UCT) and urethral gonorrhoea (UGC) attributable to sexual practises other than anal sex.

Methods Electronic medical records for MSM who attended 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 three months (PS, UGC) or twelve months (UCT). Amongst MSM who reported 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 who reported anal sex (OR 2.18, 95% CI 1.32 – 3.59, p = 0.002), but PS (p = 0.82) and UGC (p = 0.14) were not. For MSM who reported anal sex, condom use was protective for all three infections (all p ≤ 0.03).

Conclusions UCT rarely occurs in MSM due to sexual practises other than anal sex; however these practises appear to contribute significantly to the acquisition of PS and UGC. Our figures probably underestimate the risk involved, as men who have anal sex also engage in other sexual practises. The implication is that successful programmes to control sexually transmitted infections, particularly PS and UGC, will need to utilise additional strategies, such as frequent testing, as well as promoting condom use.