title: Comparison of clinical performance of antigen based-enzyme immunoassay (EIA) and major outer membrane protein (MOMP)-PCR for detection of genital Chlamydia trachomatis infection.
abstract: BACKGROUND
  Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen worldwide. Early detection and treatment of C.trachomatis genital infection prevent serious reproductive complications.
  
  
  OBJECTIVE
  Performances of enzyme immunoassay (EIA) and major outer membrane protein (MOMP)-polymerase chain reaction (PCR) for diagnosis of genital C.trachomatis infection in women were compared.
  
  
  METHODS
  In this cross sectional study a total of 518 women volunteers were included (33.67±8.3 yrs) who had been referred to Gynecology clinics of Qom province, Iran, were included. Endocervical swab specimens were collected to detect lipopolysaccharide (LPS) antigen in EIA and to amplify MOMP gene of C.trachomatis in PCR. Results were confirmed using ompI nested-PCR. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated for performance of the tests. Odds ratios were determined using binary logistic regression analysis.
  
  
  RESULTS
  In total, 37 (7.14%) cases were positive by EIA and/or MOMP-PCR. All discrepant results were confirmed by nested-PCR. Sensitivity, specificity, PPV and NPV values of EIA were 59.46%, 100%, 100% and 96.98%, and those of MOMP-PCR were 97.30%, 100%, 100%, 99.79%, respectively. Reproductive complications including 2.7% ectopic pregnancy, 5.4% stillbirth, 5.4% infertility, and 10.8% PROM were recorded. The risk of developing chlamydiosis was increased 4.8-fold in volunteers with cervicitis (p<0.05; OR 4.80; 95% CI 1.25-18.48).
  
  
  CONCLUSIONS
  C.trachomatis infection should be regarded in women of reproductive ages especially those with cervicitis. Primary screening of women by using the low cost antigen-EIA is recommended; however, due to the low sensitivity of Ag-EIA, verification of the negative results by a DNA amplification method is needed.
authors.affiliation: Department of Microbiology and Immunology, Faculty of Medicine, Qom University of Medical Sciences, Qom, Iran.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Nateghi Rostami
authors.affiliation: Department of Obstetrics and Gynecology, Vali-Asr Reproductive Health Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Batool
authors.initials: B
authors.lastname: Hossein Rashidi
authors.affiliation: Department of Microbiology, Islamic Azad University, Qom Branch, Qom, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Aghsaghloo
authors.affiliation: Department of Microbiology, Islamic Azad University, Qom Branch, Qom, Iran.
authors.forename: Razieh
authors.initials: R
authors.lastname: Nazari
keywords: Chlamydia trachomatis; Enzyme immunoassay; Nested PCR; Pregnancy complications