Evaluation of the Roche cobas® CT/NG Test for Detection of... : Sexually Transmitted Diseases (original) (raw)

Original Study

Evaluation of the Roche cobas® CT/NG Test for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in Male Urine

Taylor, Stephanie N. MD*; Liesenfeld, Oliver MD†; Lillis, Rebecca A. MD*; Body, Barbara A. PhD‡; Nye, Melinda PhD‡; Williams, James BS§; Eisenhut, Carol MD¶; Hook, Edward W. III MD‖; Van Der Pol, Barbara PhD§,**

From the *Louisiana State University Health Sciences Center, New Orleans, LA; †Roche Molecular Systems, Pleasanton, CA; ‡Laboratory Corporation of America, Burlington, NC; §Indiana University School of Medicine, Indianapolis, IN; ¶DCL Laboratories (Laboratory Corporation of America), Indianapolis, IN; ‖University of Alabama at Birmingham and Jefferson County Health Department, Birmingham, AL; and **Indiana University School of Public Health, Bloomington, IN

The authors thank the staff of all testing (LabCorp, Burlington, NC; Infectious Diseases Lab, IN University School of Medicine, Indianapolis, IN; DCL Medical Laboratories, Indianapolis, IN; LSU Health Sciences Center, New Orleans, LA) and collection sites (University of Alabama at Birmingham, Birmingham, AL; Lyndhurst Clinical Research, Winston-Salem, NC; Women's Health Practice, Champaign, IL; Marion County Health Department, IN University School of Medicine, Indianapolis, IN; Quality of Life Medical & Research Center, LLC, Tucson, AZ; Axis Clinical Trials, Los Angeles, CA; Planned Parenthood Southeastern PA, Philadelphia, PA; Planned Parenthood, Mar Monte, Sacramento, CA; Healthcare Clinical Data, Inc., North Miami, FL; Planned Parenthood Houston and Southeast Texas, Inc. [Planned Parenthood Gulf Coast Inc.], Houston, TX; LSU Health Sciences Center, Section of Infectious Diseases, New Orleans, LA). They thank Rui Li for expert statistical support.

Supported by Roche Molecular Systems, Pleasanton, CA. S.T. has received research support or received honoraria from Gen-Probe, Cepheid, Roche Molecular Systems and Becton Dickinson; O.L. is an employee of Roche Molecular Systems; B.B. has served on advisory boards sponsored by Roche Molecular System, Roche Diagnostics, and Becton Dickinson; M.N. has served on an advisory board sponsored by Gen-Probe; E.H. has received research support or honoraria from Roche Molecular Systems, Becton-Dickinson, Gen-Probe, Abbott Molecular Diagnostics, Siemens Molecular, and Cepheid and has served as a consultant for Abbott Molecular Diagnostics; B.V. has received honoraria or research support from Abbott Molecular Diagnostics, Beckman Coulter, Becton Dickinson, Cepheid, Idaho Technologies, Inc., PinPoint Medical, Roche Diagnostics, and Roche Molecular Systems.

Correspondence: Stephanie N. Taylor, MD, 517 N Rampart St, New Orleans, LA 70112. E-mail: [email protected].

Received for publication September 21, 2011, and accepted February 1, 2012.

Abstract

Background:

The Roche cobas® CT/NG test (c4800), performed on the cobas 4800 system, is a new diagnostic assay using an automated workstation to isolate nucleic acids from clinical specimens and a real-time instrument for the detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). This study compared the performance characteristics of the c4800 with the Becton Dickinson ProbeTec™ CT/GC Qx assay (Qx) and Gen-Probe® Aptima Combo 2 (AC2) assay for the detection of CT and NG in male urine using patient-infected-status (PIS).

Methods:

Urine and urethral swabs were obtained from men attending STD, family planning, or OB/GYN clinics from 11 geographically distinct locations. Aliquot order was randomized for urine specimens between AC2, c4800, and Qx. Urethral swabs were randomized between AC2 and Qx. Urethral swabs were only used to define PIS and were not tested on the c4800. A participant was considered infected if the 2 comparator assays with different molecular targets had positive results from either sample type.

Results:

A total of 790 men were screened, with 768 evaluable for CT and NG. Symptoms were reported in 296 (38.5%) participants. For urine, the overall sensitivity and specificity of the c4800 assay for CT were 97.6% and 99.5%, respectively, when compared with PIS. Sensitivity and specificity for NG were 100% and 99.7%, respectively.

Conclusions:

The c4800 has excellent sensitivity and specificity for male urine specimens when compared with PIS. Assay performance was similar in symptomatic and asymptomatic men and was equivalent to nucleic acid amplification tests that are currently on the market.