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 four second-generation nucleic acid amplification assays performed on self-collected vaginal swabs (SCVS) and first void urines (FVU) from 575 women, SCVS identified more infections than FVU in all assays. Prevalence was 9% (53/575) for Chlamydia trachomatis and 2% (11/575) for Neisseria gonorrhoeae . Clinical sensitivities for testing SCVS for C. trachomatis were 98.1% on Tigris® and 96.2% on Panther® instruments for Aptima Combo 2® (Hologic|GenProbe), 98.0% for RealTi m e® CT/NG on an m2000® instrument (Abbott), 90.6% for ProbeTec™ ET CT/GC Q x on the Viper™ system (Becton Dickinson) and 84.6% for cobas® 4800 CT/NG on the cobas® 4800 platform (Roche), respectively. Clinical sensitivity for C. trachomatis on FVU for Aptima Combo 2 were 88.7% (Tigris) and 88.0% (Panther), 76.9% for RealTi m e CT/NG, 75.5% for ProbeTec CT/GC Q x and 81.1% for cobas 4800 CT/NG. Clinical sensitivities of the assays on limited positives ranged from 63.6% to 100% for N. gonorrhoeae . Specificities for both infections ranged from 98.4-100%. Differences in analytical sensitivities and amounts of molecular targets in clinical samples but not inhibitors of amplification may explain differences in clinical sensitivities.