How accurate is presumptive Chlamydia trachomatis treatment? A 6-month clinical audit of a walk-in sexual health service

Background Chlamydia trachomatis (chlamydia) is highly prevalent and is an important sexually transmitted infection as it can lead to increased risk of HIV seroconversion; and if left untreated, can cause infertility in women. Clinical guidelines recommend treating chlamydia presumptively when presenting symptomatically; however, clinicians are now questioning this due to increasing prevalence of antimicrobial resistance. Methods To determine the accuracy of presumptive chlamydia treatment practices at a walk-in sexual health service in regional Australia, we audited all same-day screen and treat presentations prescribed azithromycin over a 6-month period in 2018. Results A total of 325 cases were included in the analysis. Over half (54%) the presentations returned negative pathology for all pathogens investigated. One quarter (25%) of presentations were positive for chlamydia, and (4%) reported a dual infection. A further one fifth (20%) were negative for chlamydia but positive for another pathogen. More symptomatic males than females returned positive pathology for chlamydia (8% vs 4%). Conclusions While presumptive treatment is recommended in the current guidelines, our findings indicate this resulted in over-treatment. Considering the increasing resistance patterns for Mycoplasma genitalium, which include azithromycin, presumptive treatments need to balance immediate client care needs against long-term community antimicrobial resistance outcomes. This internal audit provided a feedback mechanism to the walk-in sexual service, enabling modification of practices to provide more precise, individual clinical care within the bounds of current STI guidelines, while balancing wider the objectives of antimicrobial stewardship.