Effect of time since exposure to Chlamydia trachomatis on chlamydia antibody detection in women: a cross-sectional study
- Patrick J Horner1,2,
- Gillian S Wills3,
- Rosy Reynolds4,
- Anne M Johnson5,
- David A Muir6,
- Alan Winston3,
- Andrew J Broadbent3,
- David Parker7,
- Myra O McClure3
- 1School of Social and Community Medicine, University of Bristol, Bristol, UK
- 2Bristol Sexual Health Centre, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
- 3Jefferiss Trust Laboratories, Wright-Fleming Institute, Imperial College, London, UK
- 4Department of Medical Microbiology, North Bristol NHS Trust, Bristol, UK
- 5Research Department of Infection & Population Health, University College, London, UK
- 6Department of Diagnostic Virology, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
- 7Novel Consulting, Crown House, Home Gardens, Dartford, UK
- Correspondence to Profeser Myra O McClure, Jefferiss Research Trust Laboratories, Wright-Fleming Institute, Faculty of Medicine, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK;
- Received 15 November 2013
- Revised 29 September 2013
- Accepted 5 January 2013
- Published Online First 21 February 2013
Objectives To investigate what factors influence the detection of Chlamydia trachomatis antibody following genital tract infection.
Methods One hundred and sixty-four women with a previous history of C trachomatis infection contributed to an earlier report on the performance of chlamydia antibody ELISA assays. We undertook further analysis to explore how chlamydia antibody assay sensitivity changes with time since infection.
Results Chlamydia antibody was detected in more women soon after the last detection of chlamydia at the lower genital tract than at later times. This holds true for all tests, but the Anilabsystems IgG EIA, Medac pELISA plus ELISA and the Savyon SeroCT-IgG ELISA were less sensitive than the pgp3 ELISA and the Anilabsystems microimmunofluorescence (MIF) assay at all time points except during current infection. Fall in seropositivity in women generally occurred in the early weeks and months following the last episode of chlamydia infection. There was no clear pattern of further reduction in seropositivity after 6 months. Multiple previous episodes were associated with increased seropositivity in the pgp3 assay (two or more vs one, OR 19, p<0.001) and other tests, but the effect was significantly smaller for the Anilabs, Medac and SeroCT MOMP peptide ELISAs, but not for the MIF assay.
Conclusions Chlamydia antibody detection decreases with time since infection and this is most apparent in the first 6 months. In women who have had more than one infection, antibody remained detectable longer for all tests, but this was more marked for the pgp3 ELISA and MIF assay.