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P5.062 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
  1. C A Gaydos1,
  2. B Van Der Pol2,
  3. M Jett-Goheen1,
  4. M Barnes1,
  5. N Quinn1,
  6. C Clark3,
  7. G E Daniel3,
  8. P B Dixon3,
  9. E W Hook III3
  1. 1Johns Hopkins University, Baltimore, MD, United States
  2. 2Indiana Univ School of Public Health & School of Med, Bloomington and Indianapolis, IN, United States
  3. 3University of Alabama at Birmingham, Birmingham, AL, United States


Background 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 amplified 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). 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. Results included a specimen adequacy control result and an amplification control result. The targets were two highly conserved, non-contiguous NG-unique chromosomal targets for NG and a chromosomal CT target.

Results Compared to patient-infected-status (PIS), the Xpert results for chlamydia demonstrated sensitivities for endocervical, vaginal, and urine samples of 97.4%, 98.7%, and 97.6%, respectively, in females and in male urine a sensitivity of 97.5%. All specificity estimates were ≥ 99.4%. Results for gonorrhoea demonstrated sensitivities for endocervical, vaginal, and urine samples of 100.0%, 100.0%, and 95.6%, respectively, in females, with specificities > 99.9%. In male urine, the sensitivity for gonorrhoea was 97.50% and the specificity was 99.9%.

Conclusions The GeneXpert® System is a closed, self-contained, fully-integrated, automated platform for CT/NG testing that demonstrated excellent sensitivities and specificities in women and men. This relatively rapid short-turn-around-time test can provide results to guide treatment decisions before patients leave the clinical setting. Such rapid treatment could potentially improve chlamydia and gonorrhoea control efforts.

  • chlamydia
  • gonorrhea
  • Rapid real-time PCR

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