Trends in antimicrobial susceptibility patterns in N. gonorrhoea in Australia: Systematic review and meta-regression analysis

      Background: The widespread development of resistance among Neisseria gonorrhoeae clinical isolates to extended spectrum cephalosporins (ESCs), the last remaining options for empirical therapy, and most other antimicrobials have been reported worldwide in recent years. Surveillance systems around the world have confirmed that N. gonorrhoeae has developed resistance to all classes of antibiotics used for empirical treatment and clinical treatment failure caused by extensively resistant strains has been reported from many, particularly well-resourced, settings globally.
      Methods and materials: We conducted a systematic review and meta-regression to describe the trends in antimicrobial resistance patterns among the main classes of antibiotics used for empirical treatment and captured by the Australian Gonococcal Surveillance Program from 1981–2017. Annual reports published on the AGSP and additional studies from the reference list of articles published in English from 1980 to 2018, including data from >=100 human isolates, from any State or Territory in Australia were included. Meta-analysis using the metaprop command was carried out on all prevalence statistics from studies by antibiotic (Azithromycin, Ceftriaxone, Ciprofloxacin, Penicillin and Tetracycline), region (NSW, QLD, VIC, ACT & TAS, SA, NT and WA) and susceptibility level (susceptible, medium resistance and high resistance). Heterogeneity among studies was evaluated by using the Q test and theII2 statistic.
      Results: There is decreasing susceptibility of gonococcal isolates in Australia, to selected antimicrobials over time. In Australia, azithromycin (OR: 0.73; 95%CI 0.64–0.82) and ceftriaxone (OR: 0.69; 95%CI 0.59–0.80) shows decreasing levels of susceptibility each year. Susceptibility to azithromycin in NSW (OR: 0.57; 95%CI 0.50–0.64) and South Australia (OR: 0.50; 95%CI 0.33–0.75) shows greater decreases in susceptibility compared with the Australian average annually. Western Australia and Victoria also have decreasing levels of susceptibility to ceftriaxone over time compared to other States and Territories. All isolates remain viable to spectinomycin over the period.
      Conclusion: Significant trends in decreased susceptibility to antibiotics against gonorrhoea. Improved antimicrobial stewardship, enhanced surveillance and contact tracing are needed to identify and respond to changes in antibiotic resistance in a timely manner. Increasing awareness and continued public health follow-up of cases will interrupt the cycle of infection.