Introduction Gonorrhoea notifications are rapidly rising in men who have sex with men (MSM). We developed a model to assess mouthwash as a novel intervention for gonorrhoea control.

Methods We developed a model of Neisseria gonorrhoeae (NG) transmission to explain anatomic site-specific prevalence of gonorrhoea among MSM. The model was calibrated to available epidemiological and behavioural data. We estimated the contribution of various sexual acts to gonorrhoea incidence and evaluate the potential impacts of screening scale-up and utilisation of mouthwash on the gonorrhoea epidemic.

Results We calibrated the model to prevalence of oropharyngeal, anal and urethral gonorrhoea of 8.6% (7.7%–9.5%), 8.3% (7.4%–10.4%) and 0.20% (0.04%–0.35%), respectively, among MSM. Oropharynx to oropharynx transmission through kissing is estimated to account for nearly three quarters of all incident cases (71.6% [64.4–80.5%]%]) of gonorrhoea in MSM. Substantially increasing annual oropharynx screening for gonorrhoea from the current 40% to 100% may only halve the prevalence of gonorrhoea in MSM. In contrast, the use of mouthwash with moderate efficacy (additional 1% clearance per daily use) would further reduce the corresponding prevalence rates to 3.1% (2.2%–4.4%), 3.8% (2.3%–4.9%) and 0.10% (0.06%–0.11%), and a high efficacy mouthwash (additional 1.5% clearance per daily use) may further halve the gonorrhoea prevalence. Without oropharynx to oropharynx transmission, we could not replicate current prevalence data.

Conclusion Our model suggests that kissing may play a key role in NG transmission among MSM. Focusing on STI screening alone is not sufficient to control the rising epidemic. Promotion of regular mouthwash may achieve near elimination of gonorrhoea in MSM.