Prevalence and predictors of chlamydia co-infection among patients infected with gonorrhoea at a sexual health clinic in Sydney.

Anogenital gonorrhoea (Neisseria gonorrhoeae) is commonly diagnosed at sexual health clinics by on-site microscopy. Whether to add anti-chlamydial therapy in such situations is unclear. The medical records of all patients diagnosed with gonorrhoea between May 2005 and April 2010 at RPA Sexual Health were reviewed. Of 165 patients diagnosed with anogenital gonorrhoea, 27 (16.4%, 95% confidence interval (CI) 11.1-22.9%) were co-infected with chlamydia (Chlamydia trachomatis). Compared with those only infected with anogenital gonorrhoea, there was no correlation of anogenital gonorrhoea-chlamydia co-infection with any demographic, behavioural or clinical variables examined. Anti-chlamydial therapy should be considered for all patients with gram stain diagnosed anogenital gonorrhoea at the initial clinic visit.