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An easy to use real time PCR test for Chlamydia trachomatis and Neisseria gonorrhoeae providing results that can guide treatment choices before the patient leaves the clinic Charlotte A. Gaydos, MS, MPH, DrPH1, Barbara Van Der Pol, MPH, PhD2,3, Mary Jett- Goheen, BS1, Mathilda Barnes, MS1, Nicole Quinn, BS1, Carey Clark3, Grace E. Daniel3, Paula B. Dixon3, Edward W. Hook III, MD3 1 1 Division of Infectious Diseases, Medicine, Johns Hopkins, Baltimore, Maryland, 2 Indiana University School of Public Health, Dept Epidemiology & Biostatistics, Bloomington, Indiana, 3Indiana University School of Medicine, Division of Infectious Diseases, Indianapolis, Indiana 3 University of Alabama at Birmingham and Jefferson County Health Department, Birmingham, Alabama Background Results • New diagnostics for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) that can provide accurate, rapid, and timely results are urgently needed so that patients can be treated at the time they visit a clinic. • The Cepheid GeneXpert® (Xpert) CT/NG assay is a rapid nucleic acid amplification test (NAAT) assay that can be performed in on-site laboratories. • The assay detects DNA of CT and NG from female endocervical, patient-collected vaginal, and urine specimens, and in male urine from symptomatic and asymptomatic individuals. Methods • The Xpert test is a modular, cartridge-based, “walk-away” platform for testing which requires no manipulation from specimen loading until results are available (90 minutes). CHLAMYDIA ASSAY Female Endocervix Female Vaginal Female Urine Sensitivity Specificity 97.4% 99.6% 98.7% 99.4% 97.6% 99.8% Male Urine 97.5% 99.9% GONORRHEA ASSAY Female Endocervix Female Vaginal Female Urine Sensitivity Specificity 100% 100% 100% 99.9% 95.6% 99.9% Male Urine 97.5% 99.9% • We compared results from the Xpert assay to results from two currently approved nucleic acid amplification assays (Aptima Combo2 and ProbeTec) in 1,722 females and 1,387 males. • The targets were two highly conserved, noncontiguous NG-unique chromosomal targets for NG and a chromosomal CT target. • The Xpert assay includes a specimen adequacy control (SAC) result and a specimen processing control (SPC) result. • A patient infected status (PIS) was determined for each sample type. • The PIS for each specimen type was considered infected if a minimum of one positive result was reported by each of the two comparator NAAT assays for that specimen type (at least one from each comparator assay). Comparisons of positive test results for Cepheid Xpert CTNG (GX), Becton Dickinson ProbeTec (BD), and GenProbe Aptima Combo2 (GP) for male and female urine, and female endocervical specimens for Chlamydia trachomatis and Neisseria gonorrhoeae Conclusions • The GeneXpert® System is a closed, selfcontained, fully-integrated, automated platform for CT/NG testing that demonstrated excellent sensitivities and specificities in women and men. • This relatively rapid short-turn-around-test can provide results to guide treatment decisions before patients leave the clinical setting. Such rapid treatment could potentially improve chlamydia and gonorrhea control efforts. Bibliography Assay time: ~90 Minutes Gaydos CA, et al JCM 51:1666-1672, 2013 Tabrizi et al. JCM 51:1945-1947, 2013