Article Text
Abstract
Background Anorectal infections with Chlamydia trachomatis (CT) are common in women visiting STI outpatient clinics. We here evaluated the risk posed by sexual exposure and by alternate anatomical site infection for incident anorectal and urogenital CT.
Methods Prospective multicentre cohort study, FemCure. Participants were treated for CT, and after 4, 6, 8, 10 and 12 weeks, they self-collected anorectal and urogenital samples (swabs) for CT-DNA testing. We calculated the proportion with incident CT, that is, CT incidence (at weeks 6–12) by 2-week time-periods. Compared with no exposure (A), we estimated the risk of incident CT for (B) sexual exposure, (C) alternate site anatomic site infection and (D) both, adjusted for confounders and expressed as adjusted ORs with 95% CIs.
Results We analysed data of 385 participants contributing 1540 2-week periods. The anorectal CT incidence was 2.9% (39/1343) (95 CI 1.8 to 3.6); 1.3% (A), 1.3% (B), 27.8% (C) and 36.7% (D). The ORs were: 0.91 (95% CI 0.32 to 2.60) (B), 26.0 (95% CI 7.16 to 94.34) (C), 44.26 (95% CI 14.38 to 136.21) (D).
The urogenital CT incidence was 3.3% (47/1428) (95% CI 2.4 to 4.4); 0.7% (A), 1.9% (B), 13.9% (C) and 25.4% (D). The ORs were: 2.73 (95% CI 0.87 to 8.61) (B), 21.77 (95% CI 6.70 to 70 71) (C) and 49.66 (95% CI 15.37 to 160.41) (D).
Conclusions After initial treatment, an alternate anatomical site CT infection increased the risk for an incident CT in women, especially when also sex was reported. This may suggest a key role for autoinoculation in the re-establishment or persistence of urogenital and anorectal chlamydia infections.
- epidemiology
- azithromycin
- chlamydia infections
- women
- risk factors
Data availability statement
Data are available on reasonable request. All data relevant to the study are included in the article or uploaded as supplementary information. Coded data are available to interested researchers on reasonable request. Please send an email to helen.sijstermans@ggdzl.nl.
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Data availability statement
Data are available on reasonable request. All data relevant to the study are included in the article or uploaded as supplementary information. Coded data are available to interested researchers on reasonable request. Please send an email to helen.sijstermans@ggdzl.nl.
Footnotes
Handling editor Anna Maria Geretti
Twitter @GotzHannelore
Presented at This study has in part been presented (plenary; oral) at the STI & HIV 2021 World Congress (ISSTDR), July 2021, Amsterdam
Abstract published. Dukers-Muijrers NPL08. Chlamydia control in women and men who have sex with men: controversies and evidence on (extra)genital testing and treatment. Sexually Transmitted Infections 2021;97:A2. Supplement http://dx.doi.org/10.1136/sextrans-2021-sti.8
Contributors NHTMD-M wrote the report and performed the statistical analyses. NHTMD-M and MSvdL designed the statistical analysis. PW, ML and SMB set up and performed the laboratory analyses. NHTMD-M, CJPAH, HMG and HDV supervised the study. All authors reviewed the results, provided guidance on the method, and drafted, reviewed and provided critical feedback on the report. NHTM-D is guarantor of the study
Funding This study is funded by a governmental organisation grant from the Netherlands: Organisation for Health Research and Development (ZonMW Netherlands, registration number 50-53000-98-109 and 52-2008-002).
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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