Gonorrhea and Chlamydia Specimen Positivity Rate by Polymerase Chain Reaction at a Regional Veteran Affairs Medical Center

Abstract

Abstract Objective Sexually transmitted infections because of Neisseria gonorrhoeae (NG) and/or Chlamydia trachomatis (CT) remain a major public health problem. Although the literature describes the population-based epidemiology of CT/NG, it does not appear to contain reference points for the statistical analyses of specimen positivity rates by nucleic acid testing (NAT) with polymerase chain reaction (PCR) that would be collected by a laboratory following best laboratory and regulatory practice. For facilities that diagnose NG and CT by a real-time PCR assay, an understanding of the expected specimen positivity rate of gonorrhea and chlamydia would be helpful for monitoring the assay for quality assurance. Therefore, on behalf of the Michael J. Crescenz Veteran Affairs Medical Center (VAMC), we present this novel quality assurance study on its CT/NG specimen positivity rates conducted by NAT with PCR. Methods Quality assurance/improvement quarterly data from April 1, 2012 to September 30, 2019 were reviewed to obtain both the test volume of PCR for CT/NG and the number of positive test results at the VAMC to collate and perform statistical analyses. Testing had been performed using the Abbott m2000 RealTime System (Abbott Park, IL). Results A total of 22,709 PCR tests for CT/NG had been performed on the veteran population; of these, 502 tests were positive for NG and 744 were positive for CT. Quarterly percentage rates ranged from 1.67% to 5.30% for CT and from 1.00% to 3.25% for NG, with average rates of 3.35% and 2.22% for CT and NG, respectively. Conclusion The establishment of an expected rate of specimen positivity of CT/NG by NAT with PCR at the VAMC is a significant novel reference point in the quality assurance (QA) literature and provides a benchmark that aids tremendously in QA for the microbiology/molecular laboratory.