Performance of the Abbott RealTime CT/NG for detection of Chlamydia trachomatis and Neisseria gonorrhoeae

Abstract

A multicenter clinical study was conducted to evaluate the performance characteristics of the Abbott RealTime CT/NG assay, a multiplex real-time PCR assay, for simultaneous detection of Chlamydia trachomatis and Neisseria gonorrhoeae. The specimens were collected from a total of 3,832 male and female subjects at 16 geographically diverse sites. Specimens included male and female urine samples, male urethral swabs, female endocervical swabs, and self-collected and clinician-collected vaginal swabs. Specimens were tested with the automated Abbott RealTime CT/NG assay, Aptima Combo 2 assay (Gen-Probe), ProbeTec ET CT/GC assay (Becton Dickinson), and culture for N. gonorrhoeae. The Aptima Combo 2 assay, the ProbeTec assay, and the N. gonorrhoeae culture were used as the reference assays. For each subject, a patient infected status (PIS) was determined based on the combined results from the reference assays. The overall prevalence in female subjects was 8.9% for C. trachomatis and 3.8% for N. gonorrhoeae. The overall male prevalence was 18.2% for C. trachomatis and 16.7% for N. gonorrhoeae. The overall sensitivity and specificity of the Abbott RealTime CT/NG assay were 92.4% and 99.2% for C. trachomatis and 96.9% and 99.7% for N. gonorrhoeae, respectively. In comparison, the sensitivity and specificity, respectively, for the Aptima Combo 2 assay were 94.5% and 99.0% for C. trachomatis and 96.1% and 99.5% for N. gonorrhoeae, and those for the ProbeTec ET assay were 90.3% and 99.5% for C. trachomatis and 92.0% and 97.3% for N. gonorrhoeae in this study. The Abbott RealTime CT/NG assay offers C. trachomatis and N. gonorrhoeae dual detection with high sensitivity and specificity. The automated assay provides a useful alternative nucleic acid amplification assay for clinical laboratories and clinicians.

FIG. 1.

Sample collection protocol for female participants. Superscript numbers indicate procedures: 1, gonococcal culture; 2, Gen-Probe Aptima unisex swab specimen collection kit for endocervical swab specimens; 3, Becton Dickinson ProbeTec ET Chlamydia trachomatis/Neisseria gonorrhoeae (CT/GC) amplified DNA assay collection kit for endocervical specimens; 4, Abbott multi-Collect specimen collection kit; 5, Gen-Probe Aptima vaginal swab specimen collection kit for clinician-collected swab specimens; 6, Gen-Probe Aptima urine specimen collection kit for urine specimens; 7, Becton Dickinson ProbeTec ET urine processing kit for urine specimens.

FIG. 2.

Sample collection protocol for male participants. Superscript numbers indicate procedures: 1, gonococcal culture; 2, Gen-Probe Aptima unisex swab specimen collection kit for male urethral swab specimens; 4, Abbott multi-Collect specimen collection kit; 6, Gen-Probe Aptima urine specimen collection kit for urine specimens; 7, Becton Dickinson ProbeTec ET urine processing kit for urine specimens.