Analysis of Factors Driving Incident and Ascending Infection and the Role of Serum Antibody in Chlamydia trachomatis Genital Tract Infection

J Infect Dis. 2016 Feb 15;213(4):523-31. doi: 10.1093/infdis/jiv438. Epub 2015 Sep 7.


Background: Chlamydia trachomatis genital tract infection is a major cause of female reproductive morbidity. Risk factors for ascending infection are unknown, and the role for antibody in protection is not well established.

Methods: We recruited 225 women from urban outpatient clinics and followed them for a median of 12 months. We performed a cross-sectional analysis of serum anti-chlamydial immunoglobulin G (IgG), behavioral factors, and microbiological factors associated with endometrial infection at enrollment, and a longitudinal analysis of factors associated with incident infection.

Results: Oral contraceptives (adjusted relative risk [RR], 2.02 [95% confidence interval {CI}, 1.38-2.97]) and gonorrhea (adjusted RR, 1.66 [95% CI, 1.07-2.60]) were associated with endometrial infection. Gonorrhea (adjusted hazard ratio [HR], 3.09 [95% CI, 1.41-6.78]), cervical infection at enrollment (adjusted HR, 2.33 [95% CI, 1.07-5.11]), and exposure to uncircumcised partners (adjusted HR, 2.65 [95% CI, 1.21-5.82]) or infected partners (adjusted HR, 4.99 [95% CI, 2.66-9.39]) significantly increased the risk of incident infection. Seropositivity was associated with a reduced cervical burden (P < .05) but no differences in rates of ascending infection (adjusted RR, 1.24 [95% CI, .71-2.19]) or incident infection (adjusted HR, 0.94 [95% CI, .52-1.69]).

Conclusions: Serum anti-chlamydial IgG is not associated with a lowered rate of ascending or repeat infection. Identification of factors associated with ascending infection and increased risk of incident infection provide guidance for targeted screening of women at increased risk for sequelae.

Keywords: Chlamydia trachomatis; pelvic inflammatory disease; reproductive hormones; risk factors; serum antibody.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Antibodies, Bacterial / blood*
  • Chlamydia Infections / epidemiology*
  • Chlamydia Infections / immunology*
  • Chlamydia Infections / microbiology
  • Chlamydia trachomatis / immunology*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Immunoglobulin G / blood
  • Incidence
  • Longitudinal Studies
  • Reproductive Tract Infections / epidemiology*
  • Reproductive Tract Infections / immunology*
  • Reproductive Tract Infections / microbiology
  • Risk Factors
  • Serum / immunology*
  • Young Adult


  • Antibodies, Bacterial
  • Immunoglobulin G