Positive Predictive Value of the Becton Dickinson VIPER system and the ProbeTec GC Qx assay, in extracted mode, for detection of Neisseria gonorrhoeae.

Cassie F Pope (1) , Phillip Hay (2) , Sarah Alexander (3) , Kay Capaldi (4) , Jayshree Dave (5) , S. Tariq Sadiq (6) , Catherine A Ison (3) , Timothy Planche (4)

1 Department of Medical Microbiology, St. Georges Heathcare Trust
2 Department of Genitourinary Medicine, Courtyard Clinic, St George's Healthcare NHS Trust
3 Sexually Transmitted Bacteria Reference Laboratory (STBRL), Health Protection Agency
4 Department of Medical Microbiology, St Georges's Healthcare NHS Trust
5 Health Protection Agency Collaborating Centre, Department of Medical Microbiology, St Georges's H
6 St George's Hospital Medical School

Objectives: Performance of the new Becton Dickinson ProbeTec GC Qx assay in extracted mode, automated on the BD VIPER platform, was evaluated to ascertain whether confirmatory testing is required in our clinical setting. Methods: Positive predictive value (PPV) was determined by comparison with culture and a confirmatory NAAT based N. gonorrhoeae assay from genital and extragenital samples (rectal and pharyngeal) collected from a genito-urinary medicine clinic. Results: Among 14,223 genital samples, 149 (1.0%) patient specimens had positive results using the ProbeTec GC Qx assay, automated on the VIPER platform; 141 of these were confirmed either by culture or by a real time PCR targeting two gonococcal specific targets (PPV 94.6%; 95% confidence interval, 90%-98%). Among 840 pharyngeal samples, 26 (3.1%) were positive by the ProbeTec GC Qx assay; 13 were confirmed (PPV 50%; 95% confidence interval, 30%-70%). Among 593 rectal samples, 17 tested positive by the ProbeTec GC Qx assay; all were confirmed (PPV 100%; 80%-100%. Conclusions: High positive predictive values can be achieved when testing rectal and genital specimens using the ProbeTec GC Qx assay, automated on the VIPER platform, in a GUM clinic population.

Mots clés: LABORATORY DIAGNOSIS; NEISSERIA GONORRHOEAE

Cassie F Pope, Phillip Hay, Sarah Alexander, Kay Capaldi, Jayshree Dave, et al.. Positive Predictive Value of the Becton Dickinson VIPER system and the ProbeTec GC Qx assay, in extracted mode, for detection of Neisseria gonorrhoeae.. Sexually Transmitted Infections, 2010, 86 (6), pp.465. ⟨10.1136/sti.2010.044065⟩. ⟨hal-00576090⟩