Background Gonorrhoea treatment guidelines change when less than 95% of the infected population is successfully treated with the recommended antimicrobial. Isolates with decreased susceptibility to ceftriaxone, the current recommended therapy, have been identified and if treatment failure becomes problematic there are no new antimicrobials approved. However, Neisseria gonorrhoeaeremains susceptible to penicillin, ciprofloxacin and cefixime in at least two thirds of patients (82%, 68%, and 98% respectively) so it may be possible to target previously recommended antimicrobials to specific population sub-groups.
Methods Descriptive data from the Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP) were analysed for trends in penicillin, ciprofloxacin and cefixime susceptibility across patient sub-groups. Patient characteristics associated with antimicrobial susceptibility were identified using univariate and multivariable analyses. All analyses were performed separately for heterosexuals and men who have sex with men (MSM).
Results Heterosexual patients whose infection was susceptible to penicillin, ciprofloxacin or cefixime were of black ethnicity, penicillin: 94%, adjusted odds ratio (OR) 3.52 (95% confidence interval (CI) 2.62–4.72), ciprofloxacin: 92%, OR 5.35 (CI 4.08–7.0), cefixime: 99%, OR 3.62 (CI 1.91–6.84), or with concurrent chlamydia infection (penicillin: 94%, 2.34, 1.75–3.13, ciprofloxacin: 92%, 3.37, 2.59–4.38, cefixime: 99%, 2.32, 1.23–4.39). Additionally isolates susceptible to penicillin were found in patients aged 13–24 years (92%, 3.54, 2.63–4.77) or without symptoms (92%, 1.75, 1.28–2.4). All isolates from heterosexuals were fully susceptible to cefixime. In all sub-groups of the MSM population the proportion of isolates susceptible to penicillin, ciprofloxacin or cefixime was below 90%.
Conclusion The efficiency of gonorrhoea treatment could be maximised by targeting the use of previous first line therapies to specific heterosexual population sub-groups if the treatment threshold is reduced to 90%. Treatment of any MSM with penicillin, ciprofloxacin or cefixime would not be appropriate, as the proportion susceptible to these antimicrobials is much less than for the heterosexual population.