title: Prevalence of Chlamydia infection among women visiting a gynaecology outpatient department: evaluation of an in-house PCR assay for detection of Chlamydia trachomatis.
abstract: BACKGROUND
  Screening women for Chlamydia trachomatis infection in developing countries is highly desirable because of asymptomatic infection. The existing diagnostic methods in developing countries are not effective and their sensitivity fall below 45.0% which leads to further spread of infection. There is an urgent need for improved and cost effective diagnostic tests that will reduce the burden of sexually transmitted infections in the developing world.
  
  
  METHODS
  Prevalence of C. trachomatis infection among women visiting gynaecology department of Hindu Rao hospital in Delhi, India was determined using Roche Amplicor Multi Well Plate kit (MWP) as well as using in-house PCR assay. We used 593 endocervical swabs for clinical evaluation of the in-house developed assay against Direct Fluorescence Assay (DFA; Group I n = 274) and Roche Amplicor MWP kit (Group II, n = 319 samples) and determined the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of the in-house developed assay.
  
  
  RESULTS
  We detected 23.0% positive cases and there was a higher representation of women aged 18-33 in this group. An in-house PCR assay was developed and evaluated by targeting unique sequence within the gyrA gene of C. trachomatis. Specificity of the reaction was confirmed by using genomic DNA of human and other STI related microorganisms as template. Assay is highly sensitive and can detect as low as 10 fg of C. trachomatis DNA. The resolved sensitivity of in-house PCR was 94.5% compared with 88.0% of DFA assay. The high specificity (98.4%) and sensitivity (97.1%) of the in-house assay against Roche kit and availability of test results within 3 hours allowed for immediate treatment and reduced the risk of potential onward transmission.
  
  
  CONCLUSIONS
  The in-house PCR method is cost effective (~ 20.0% of Roche assay) and hence could be a better alternative for routine diagnosis of genital infection by C. trachomatis to facilitate improved screening and treatment management.
authors.affiliation: Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi-110007, India.
authors.forename: Achchhe L
authors.initials: AL
authors.lastname: Patel
authors.forename: Divya
authors.initials: D
authors.lastname: Sachdev
authors.forename: Poonam
authors.initials: P
authors.lastname: Nagpal
authors.forename: Uma
authors.initials: U
authors.lastname: Chaudhry
authors.forename: Subash C
authors.initials: SC
authors.lastname: Sonkar
authors.forename: Suman L
authors.initials: SL
authors.lastname: Mendiratta
authors.forename: Daman
authors.initials: D
authors.lastname: Saluja
mesh_terms: D000328:Adult; D002690:Chlamydia Infections / Q000175:diagnosis* / Q000453:epidemiology; D002692:Chlamydia trachomatis / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000032:analysis; D003906:Developing Countries; D005260:Female; D005831:Genital Diseases, Female / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010044:Outpatient Clinics, Hospital; D016133:Polymerase Chain Reaction / Q000379:methods*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis* / Q000453:epidemiology; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial; D011933:Reagent Kits, Diagnostic
references.citation: Clin Microbiol Infect. 2009 Jan;15(1):4-10
references.pmid: 19220334
references.citation: Genitourin Med. 1996 Feb;72(1):20-6
references.pmid: 8655162
references.citation: Eur J Clin Microbiol Infect Dis. 2003 Feb;22(2):118-21
references.pmid: 12627288
references.citation: J Clin Pathol. 1993 Sep;46(9):822-5
references.pmid: 8227431
references.citation: Plasmid. 1987 Nov;18(3):205-14
references.pmid: 3444859
references.citation: Microbiology (Reading). 2010 May;156(Pt 5):1394-1404
references.pmid: 20093289
references.citation: Nature. 2006 Nov 23;444 Suppl 1:59-72
references.pmid: 17159895
references.citation: Clin Microbiol Rev. 1997 Jan;10(1):160-84
references.pmid: 8993862
references.citation: Int J STD AIDS. 2000 Jan;11(1):45-8
references.pmid: 10667900
references.citation: J Epidemiol Community Health. 2009 Oct;63(10):805-6
references.pmid: 19556616
references.citation: J Clin Pathol. 1993 Oct;46(10):912-4
references.pmid: 8227407
references.citation: J Med Microbiol. 2009 Jul;58(Pt 7):867-873
references.pmid: 19502371
references.citation: Sex Transm Dis. 2005 Jan;32(1):13-9
references.pmid: 15614116
references.citation: J Clin Microbiol. 2003 Jun;41(6):2700-2
references.pmid: 12791909
references.citation: Sex Transm Infect. 1998 Jun;74 Suppl 1:S118-22
references.pmid: 10023361
references.citation: J Infect Dis. 2002 Feb 1;185(3):324-31
references.pmid: 11807714
references.citation: J Clin Microbiol. 1998 Feb;36(2):391-4
references.pmid: 9466747
references.citation: Infect Immun. 1997 Jul;65(7):2965-9
references.pmid: 9199473
references.citation: Acta Cytol. 2002 May-Jun;46(3):540-4
references.pmid: 12040650
references.citation: Diagn Microbiol Infect Dis. 2002 Jan;42(1):43-51
references.pmid: 11821171
references.citation: Sex Transm Dis. 2005 Dec;32(12):745-51
references.pmid: 16314771
references.citation: Sex Transm Infect. 2003 Apr;79(2):111-5
references.pmid: 12690130
references.citation: Sex Transm Infect. 2000 Aug;76(4):303-6
references.pmid: 11026889
references.citation: Sex Transm Infect. 2006 Dec;82 Suppl 5:v1-6
references.pmid: 17151023
references.citation: Sex Transm Dis. 1994 Jul-Aug;21(4):191-5
references.pmid: 7974068
references.citation: Acta Cytol. 2006 May-Jun;50(3):277-83
references.pmid: 16780021
references.citation: Sex Transm Dis. 2003 Sep;30(9):671-9
references.pmid: 12972788
references.citation: J Clin Microbiol. 2000 Jan;38(1):138-45
references.pmid: 10618077
references.citation: J Clin Microbiol. 2004 Jul;42(7):3041-5
references.pmid: 15243057
references.citation: Cell Mol Biol (Noisy-le-grand). 1995 Jul;41(5):731-6
references.pmid: 7580853
references.citation: J Clin Microbiol. 1993 Jul;31(7):1753-8
references.pmid: 7688753
references.citation: Natl Med J India. 1994 Mar-Apr;7(2):57-9
references.pmid: 8019395
references.citation: J Clin Microbiol. 2001 Apr;39(4):1429-35
references.pmid: 11283067
references.citation: Nature. 2006 Nov 23;444 Suppl 1:73-9
references.pmid: 17159896
references.citation: Plasmid. 1986 Jul;16(1):52-62
references.pmid: 3016782
references.citation: Sex Transm Infect. 1998 Aug;74(4):289-93
references.pmid: 9924472
references.citation: Genitourin Med. 1995 Aug;71(4):247-50
references.pmid: 7590718
references.citation: Lancet. 1996 Nov 9;348(9037):1308-9
references.pmid: 8909390
references.citation: J Clin Microbiol. 1995 Nov;33(11):3049-53
references.pmid: 8576375
references.citation: Stud Fam Plann. 2000 Mar;31(1):55-68
references.pmid: 10765538
references.citation: Sex Transm Dis. 2001 Jul;28(7):372-8
references.pmid: 11460020
references.citation: J Infect Dis. 1991 Feb;163(2):233-9
references.pmid: 1988508
references.citation: Jpn J Infect Dis. 2003 Jun;56(3):88-92
references.pmid: 12944672
references.citation: Eur J Clin Microbiol Infect Dis. 2009 Nov;28(11):1391-3
references.pmid: 19657683
references.citation: Best Pract Res Clin Obstet Gynaecol. 2002 Dec;16(6):789-99
references.pmid: 12473282
references.citation: Sex Transm Infect. 2001 Oct;77(5):344-50
references.pmid: 11588280