Vulvovaginal-Swab or First-Catch Urine Specimen To Detect Chlamydia trachomatis in Women in a Community Setting?

• Published in: Journal of Clinical Microbiology 2006-12, Vol.44 (12), p.4389-4394
• Main Authors: Skidmore, Sue, Horner, Paddy, Herring, Alan, Sell, Joanne, Paul, Ian, Thomas, Jane, Caul, E. Owen, Egger, Matthias, McCarthy, Anne, Sanford, Emma, Salisbury, Chris, Macleod, John, Sterne, Jonathan A.C, Low, Nicola
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Bacteriological Techniques; Bacteriology; Biological and medical sciences; Chlamydia Infections - diagnosis; Chlamydia Infections - microbiology; Chlamydia trachomatis; Chlamydia trachomatis - isolation & purification; Chlamydiology and Rickettsiology; Female; Fundamental and applied biological sciences. Psychology; Humans; Immunoenzyme Techniques; Infectious diseases; Male; Medical sciences; Microbiology; Miscellaneous; Nucleic Acid Amplification Techniques; Sensitivity and Specificity; Urine - microbiology; Vagina - microbiology; Vulva - microbiology
• ISSN: 0095-1137; 1098-660X; 1098-5530
• DOI: 10.1128/JCM.01060-06

Screening for chlamydia in women is widely recommended. We evaluated the performance of two nucleic acid amplification tests for detecting Chlamydia trachomatis in self-collected vulvovaginal-swab and first-catch urine specimens from women in a community setting and a strategy for optimizing the sensitivity of an amplified enzyme immunoassay on vulvovaginal-swab specimens. We tested 2,745 paired vulvovaginal-swab and urine specimens by PCR (Roche Cobas) or strand displacement amplification (SDA; Becton Dickinson). There were 146 women infected with chlamydia. The assays detected 97.3% (95% confidence interval [CI], 93.1 to 99.2%) of infected patients with vulvovaginal-swab specimens and 91.8% (86.1 to 95.7%) with urine specimens. We tested 2,749 vulvovaginal-swab specimens with both a nucleic acid amplification test and a polymer conjugate-enhanced enzyme immunoassay with negative-gray-zone testing. The relative sensitivities obtained after retesting specimens in the negative gray zone were 74.3% (95% CI, 62.8 to 83.8%) with PCR and 58.3% (95% CI, 46.1 to 69.8%) with SDA. In community settings, both vulvovaginal-swab and first-catch urine specimens from women are suitable substrates for nucleic acid amplification tests, but enzyme immunoassays, even after negative-gray-zone testing, should not be used in screening programs.