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Background Antimicrobial resistant (AMR) gonorrhoea is a global public health threat. Diagnoses of gonorrhoea have increased in England over the last decade. Guidelines in UK now recommend single dose ceftriaxone, so preserving the efficacy of ceftriaxone is essential. In England, over half of tested isolates remain sensitive to previously recommended drugs, e.g. ciprofloxacin. We evaluate options for improving antibiotic stewardship, through better use of existing surveillance data or new diagnostic tests. Methods We previously developed an agent-based stochastic network model of gonorrhoea transmission, including ciprofloxacin-sensitive and resistant strains for MSM. This has been modified, to add a heterosexual population and a full model including bridging between MSM and heterosexuals. A novel feature is the time-varying network which breaks and reforms connections within a fixed cumulative network to capture behavioural heterogeneity in duration and number of partnerships. We explored different strategies to facilitate individualised treatment selection, including discriminatory POCT, and selecting treatment based on either index case or partner susceptibility. Results Our MSM model suggests, based on 50% resistance to ciprofloxacin at baseline, that using POCT to detect ciprofloxacin-sensitive infections could reduce ceftriaxone doses by 70%. If index case susceptibility information were to be used to determine partner treatment, ceftriaxone use could be reduced by 27%. In the heterosexual model, the prevalence is much lower and could only be maintained through assuming higher transmission probability or duration of infection or via bridging to the higher prevalence MSM group. Conclusion Novel POCT which identify susceptible infections are likely to come to market soon, but are costly. Mathematical models can evaluate the trade-offs between increasing test costs and reduced time to treatment or between delaying treatment to confirm susceptibility and reduce use of ceftriaxone in partners. The flexible model structure will be used in future to implement evolution of resistance and the impact of vaccination. Disclosure No significant relationships.

Introduction Antimicrobial resistant (AMR) gonorrhoea is a global public health threat. In London, diagnoses in men who have sex with men (MSM) have more than quadrupled from 2010 to 2015. Importantly, our last-line treatment (ceftriaxone) is used in first-line dual therapy. However, over half of tested isolates are still sensitive to older drugs, e.g. ciprofloxacin. Discriminatory point-of-care tests (POCT) to detect drug sensitivity are under development, enabling individualised treatment decisions. Methods An individual-based transmission model of gonorrhoea infection in MSM was developed, incorporating ciprofloxacin-sensitive and resistant strains, using novel heuristic approach to capture partnership dynamics. We explored different strategies to improve treatment selection including a) discriminatory POCT, b) partner treatment based on index case susceptibility, and c) variably delayed positivity testing prior to treatment (pre-screening). Results The flexible model structure enabled us to credibly simulate London gonorrhoea transmission dynamics - assuming 2–10% prevalence and 10–50 daily diagnoses per 100,000 MSM. Simulations show that a) using POCT to detect ciprofloxacin sensitive infections resulted in a 70% decrease in ceftriaxone doses, and b) using index case sensitivity profile to direct treatment of partners could reduce ceftriaxone use by 27%. Discussion POCT are likely to dramatically reduce reliance on ceftriaxone. In the meantime, we could use existing data more informatively. If lab turnaround times are fast enough, index case sensitivity profiles could be used to select effective treatments for partners. This new framework addresses limitations of previous models and provides a flexible platform for exploring control options for AMR gonorrhoea.