Head-to-head comparison of second-generation nucleic acid amplification tests for detection of Chlamydia trachomatis and Neisseria gonorrhoeae on urine samples from female subjects and self-collected vaginal swabs.
In a comparison of 4 second-generation nucleic acid amplification tests performed with self-collected vaginal swab (SCVS) and first-void urine (FVU) specimens from 575 women, SCVS specimens indicated more infections than did FVU specimens in all assays. The prevalence rates were 9% (53/575 patients) for Chlamydia trachomatis and 2% (11/575 patients) for Neisseria gonorrhoeae. The clinical sensitivities for testing SCVS specimens for C. trachomatis were 98.1% on a Tigris system and 96.2% on a Panther system for the Aptima Combo 2 assay (Hologic Gen-Probe), 98.0% for the RealTime CT/NG assay on an m2000 instrument (Abbott), 90.6% for the ProbeTec CT/GC Q(x) assay on the Viper system (Becton Dickinson), and 84.6% for the cobas CT/NG assay on the cobas 4800 platform (Roche). Clinical sensitivities for C. trachomatis in FVU specimens were 88.7% (Tigris) and 88.0% (Panther) for the Aptima Combo 2 assay, 76.9% for the RealTime CT/NG assay, 75.5% for the ProbeTec CT/GC Q(x) assay, and 81.1% for the cobas CT/NG assay. Clinical sensitivities of the assays for N. gonorrhoeae, with limited positive results, ranged from 63.6% to 100%. Specificities for both infections ranged from 98.4 to 100%. Differences in analytical sensitivities and levels of molecular targets in clinical samples but not inhibitors of amplification may explain the differences in clinical sensitivities.
St. Joseph's Healthcare/McMaster University, Hamilton, Ontario, Canada chernesk@mcmaster.ca.
Max
M
Chernesky
St. Joseph's Healthcare/McMaster University, Hamilton, Ontario, Canada.
Dan
D
Jang
St. Joseph's Healthcare/McMaster University, Hamilton, Ontario, Canada.
Jodi
J
Gilchrist
Queen Elizabeth II Health Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada.
Todd
T
Hatchette
Centre de santé et de services sociaux de Trois-Rivières, Trois-Rivières, Quebec, Canada.
André
A
Poirier
Public Health Laboratory, St. John's, Newfoundland and Labrador, Canada.
Jean-Frederic
JF
Flandin
St. Joseph's Healthcare/McMaster University, Hamilton, Ontario, Canada.
Marek
M
Smieja
Division of Community Health and Humanities, Memorial University, St. John's, Newfoundland and Labrador, Canada Department of Oncology, McGill University, Montreal, Quebec, Canada.
Sam
S
Ratnam
D002690:Chlamydia Infections / Q000175:diagnosis*; D002692:Chlamydia trachomatis / Q000302:isolation & purification; D005260:Female; D006069:Gonorrhea / Q000175:diagnosis*; D006257:Head; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009344:Neisseria gonorrhoeae / Q000302:isolation & purification; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012646:Self Administration; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods*; D014556:Urine / Q000382:microbiology*; D014621:Vagina / Q000382:microbiology*