Managing contacts of chlamydia: should clinics implement a test and wait process?

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.

Analysis of chlamydia contacts and the look-back interval at a UK sexual health clinic

Guidance on contact tracing in Chlamydia trachomatis (CT) is limited. CT contacts data over 12 months (1 December 2018-29 November 2019) at a UK sexual health clinic were analysed to determine the appropriateness of the currently recommended six-month 'look-back' interval. Age and sex of CT contacts were associated with clinical outcomes. Subgroups of 100 CT positive/negative contacts (each N = 100) were randomly selected. The relationship between time since sexual intercourse with the index case (Last Sexual Intercourse; LSI) and CT positivity was examined; suitability of varying look-back intervals was explored. Of 891 CT contacts (mean age = 25.0 years, 66.2% men), 66.9% tested positive for CT. Positive CT contacts were significantly younger (23.8 ± 6.8 years vs. 27.4 ± 9.1, p < 0.001) and more often women (36.4% vs. 28.5%, p = 0.018) than negative contacts. In the subgroups, the Mann-Whitney U test revealed no significant difference between the LSI of positive and negative contacts (p = 0.081). 95% of positive CT contacts (N = 82) were captured within a hypothetical three-month look-back interval. While most CT positive contacts were captured within three months, they appeared to remain proportionately represented beyond this point. Although this supports current guidelines, further research should investigate whether CT contacts involved in longer look-back intervals may require disproportionately greater resources to trace.