Substantial increase in yield of Neisseria gonorrhoeae testing 2008–2013 at a Sydney metropolitan sexual health clinic: an observational study

Background A substantial increase in gonorrhoea notifications in New South Wales has been observed in recent years. Methods: We assessed yield of testing and characteristics of those diagnosed with gonorrhoea from January 2008 to December 2013 at RPA Sexual Health in the inner-west of Sydney. Yield was defined as the proportion of testing occasions which were positive for gonorrhoea. Generalised estimating equations were used to calculate trends in yield over time. Results: During the 6-year study period, 6456 individuals (4308 males, 2124 females, 24 transgender individuals) were tested on 12 799 occasions; this included 2441 gay and bisexual men (GBM) who were tested on 6945 occasions. Over the study period there was a significant increase in testing at genital, anorectal and pharyngeal sites (P-trend <0.001 for all). In total, gonorrhoea was detected on 668 testing occasions among 536 individuals (5.2%). Overall, 254/12765 (2.0%) of genital tests, 251/7326 (3.4%) of anorectal tests and 342/8252 (4.1%) of pharyngeal tests were positive. There was a significant increase in overall gonorrhoea yield from 2.2% in 2008 to 7.1% in 2013 (P-trend <0.001). This temporal increase in gonorrhoea yield was observed in heterosexual males (P < 0.001), heterosexual females (P-trend = 0.008), female sex workers (P-trend = 0.006), HIV-positive GBM and HIV-negative GBM (both P < 0.001) and at all anatomical sites (P-trend <0.001 for all). Conclusions: From 2008 to 2013, we observed a greater than threefold increase in yield of gonorrhoea testing disproportionately affecting GBM, although the increase also occurred in other subpopulations and at all anatomic sites. More frequent and comprehensive testing could potentially reduce the high and increasing community prevalence of gonorrhoea.