Objectives Chlamydia trachomatis is the most commonly diagnosed bacterial STI. Lack of prevalence and risk factor data for rectal chlamydia in women has testing and treatment implications, as azithromycin (a first-line urogenital chlamydia treatment) may be less effective for rectal chlamydia. We conducted a systematic review of studies on women in high-income countries to estimate rectal chlamydia prevalence, concurrency with urogenital chlamydia and associations with reported anal intercourse (AI).
Design Systematic review and four meta-analyses conducted using random-effects modelling.
Data sources Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, PsycINFO and the Cochrane Database were searched for articles published between January 1997 and October 2017.
Eligibility criteria Studies reporting rectal chlamydia positivity in heterosexual women aged ≥15 years old in high-income countries were included. Studies must have used nucleic acid amplification tests and reported both the total number of women tested for rectal chlamydia and the number of rectal chlamydia infections detected. Conference abstracts, case reports and studies with self-reported diagnoses were excluded. Data extracted included setting, rectal and urogenital chlamydia testing results, AI history, and demographics.
Results Fourteen eligible studies were identified, all among diverse populations attending sexual health services. Among routine clinic-attending women, summary rectal chlamydia positivity was 6.0% (95% CI 3.2% to 8.9%); summary concurrent rectal chlamydia infection was 68.1% in those who tested positive for urogenital chlamydia (95% CI 56.6% to 79.6%); and of those who tested negative for urogenital chlamydia, 2.2% (95% CI 0% to 5.2%) were positive for rectal chlamydia. Reported AI was not associated with rectal chlamydia (summary risk ratio 0.90; 95% CI 0.75 to 1.10).
Conclusions High levels of rectal chlamydia infection have been shown in women with urogenital chlamydia infection. The absence of association between reported AI and rectal chlamydia suggests AI is not an adequate indicator for rectal testing. Further work is needed to determine policy and practice for routine rectal testing in women.
- chlamydia trachomatis
- systematic reviews
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Handling editor Nicola Low
Contributors SCW, STS, JMS, EMH-E, KF and JKD had the initial idea and concept of undertaking this systematic review. JMS and SCW developed the idea and wrote the study protocol which laid out the search strategy and study design. NLC undertook the literature search and reviewed the titles. NLC, KT, CB and KF reviewed the abstracts and full-text papers. JMS and JKD evaluated the included papers for risk of bias. NLC, CB and KF extracted and collected the data. NLC designed and undertook the meta-analyses, with contributions from all authors. NLC wrote the first draft of the paper and developed the figures. All authors contributed to the writing of the manuscript and approved the final version.
Funding Project funded by Public Health England, the UKCRC Translational Infection Research (TIR) Initiative supported by the Medical Research Council, eSTI2 Consortium (grant number G0901608), and the National Institute for Health Research (NIHR) i4i Programme (grant number II-LB-0214-20005). The funding bodies had no role in the design of the study, in the writing of the manuscript and in the decision to submit the manuscript for publication. The views expressed are those of the authors and not necessarily those of the NIHR, the NHS or the Department of Health.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement No additional data available.
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