title: Effect of time since exposure to Chlamydia trachomatis on chlamydia antibody detection in women: a cross-sectional study.
abstract: OBJECTIVE
  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.
authors: School of Social and Community Medicine, University of Bristol, Bristol, UK.
authors: Patrick J
authors: PJ
authors: Horner
authors: Gillian S
authors: GS
authors: Wills
authors: Rosy
authors: R
authors: Reynolds
authors: Anne M
authors: AM
authors: Johnson
authors: David A
authors: DA
authors: Muir
authors: Alan
authors: A
authors: Winston
authors: Andrew J
authors: AJ
authors: Broadbent
authors: David
authors: D
authors: Parker
authors: Myra O
authors: MO
authors: McClure
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial; D002690:Chlamydia Infections / Q000453:epidemiology / Q000276:immunology*; D002692:Chlamydia trachomatis / Q000302:isolation & purification*; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D011237:Predictive Value of Tests; D012725:Sexual Behavior; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D000907:Antibodies, Bacterial
keywords: Antibodies; Chlamydia Serology; Chlamydia Trachomatis; Seroprevalence