Objectives Spontaneous clearance of Chlamydia trachomatis (CT) infections can occur between diagnosis and treatment. We followed CT patients to assess clearance using a conventional definition (no total CT-DNA, assessed by routine quantitative PCR methods) and a definition accounting for viability, assessed by viability PCR testing.
Methods Three outpatient STI clinics included CT-diagnosed women (The Netherlands, 2016–2017, FemCure study); participants had vaginal CT (vCT) and rectal CT (rCT) (group A: n=155), vCT and were rectally untested (group B: n=351), single vCT (group C: n=25) or single rCT (group D: n=29). Follow-up (median interval 9 days) vaginal and rectal samples underwent quantitative PCR testing (detecting total CT-DNA). When PCR positive, samples underwent V-PCR testing to detect ‘viable CT’ (CT-DNA from intact CT organisms; V-PCR positive). ‘Clearance’ was the proportion PCR-negative patients and ‘clearance of viable CT’ was the proportion of patients testing PCR negative or PCR positive but V-PCR negative. We used multivariable logistic regression analyses to assess diagnosis group (A–D), age, days since initial CT test (diagnosis) and study site (STI clinic) in relation to clearance and clearance of viable CT.
Results Clearance and clearance of viable CT at both anatomic sites were for (A) 0.6% and 3.9%; (B) 5.4% and 9.4%; (C) 32.0% and 52.0% and (D) 27.6% and 41.4%, respectively. In multivariate analyses, women with single infections (groups C and D) had higher likelihood of clearance than women concurrently infected with vCT and rCT (p<0.001).
Of rectally untested women (group B), 76.9% had total CT-DNA and 46.7% had viable CT (V-PCR positive) at the rectal site.
Conclusions Of untreated female vCT patients who had CT also at the rectal site, or who were rectally untested, only a small proportion cleared CT (in fact many had viable CT) at their follow-up visit (median 9 days). Among single site infected women clearance was much higher.
Trial registration number NCT02694497.
- chlamydia trachomatis
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Handling editor Jane S Hocking
Presented at Preliminary results of the paper have been presented at the STI & HIV 2019 World Congress Joint Meeting of the 23rd ISSTDR & 20th IUSTI, Vancouver, Canada. 14–17 July 2019 (poster presentation 645).
Correction notice The article has been corrected since it was published online first. The Acknowledgement section is now included in the updated version.
Contributors NHTMD coordinated the study, performed the statistical analyses and wrote and drafted the paper; NHTMD, CJPAH, PW, HMG, SMB, MSvdL and HDV designed the study; KJHJ and PW coordinated laboratory data collection and testing; all authors were involved in the study design, critically edited the manuscript and approved the final manuscript.
Funding This study is funded by a governmental organisation grant from the Netherlands Organization for Health Research and Development (ZonMW Netherlands) (registration number 50-53000-98-109).
Competing interests None declared.
Patient consent for publication Not required.
Ethics approval All participants provided written informed consent. This study was approved by the Medical Ethics Review Committee from the Maastricht University Medical Centre, Maastricht Netherlands (NL51358.068.15/METC153020, 20-01-2016) and monitored by the Clinical Trial Centre Maastricht.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available on reasonable request. Request for information on the study or for data should be sent to email@example.com.
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