ProfiCieNCy TesTiNG

The purpose of proficiency testing (PT) is to provide feedback on a laboratory’s proficiency among inter-laboratory comparisons. After choosing the PT provider, the laboratory or testing facility will receive “blind” samples. Samples are tested as patients are tested. Results are submitted to the PT provider and evaluated according to specific criteria. Each laboratory or testing facility is then notified of the correctness of their results. Although CLIA waived tests are not required to participate in Proficiency testing programs, some states and accreditation agencies do require or strongly encourage participation. Check all regulations associated with your facility. Even if not required, the value in a proficiency program is the independent assessment of the quality of testing comparing peers using same sample, same test strips. As such, it becomes an important part of an overall quality assessment program. Recommended Proficiency Provider American Proficiency Institute (API) 800-333-0958

The objective of this study was to assess the utility of a supplementary PCR test following a positive Abbott m2000 PCR test result for Neisseria gonorrhoeae (NG) issued from urogenital specimens tested in the Department of Bacteriology at the Bordeaux University Hospital, France in 2011-2013.
All NG-positive PCR specimens either negative with NG culture or without culture result, were retrieved and tested with two CT/ NG PCR tests: Cepheid GeneXpert CT/NG and Roche cobas 4800 CT/NG (both targeting two genes). Analytical sensitivity of the three tests, Abbott, Cepheid and Roche for NG detection, was tested on serial dilutions (10-1 to 10-9) from one colony of NG suspended in cobas ® PCR medium (Roche).
Of 11.010 specimens tested on Abbott m2000, the global prevalence of NG was 2.5% (277/11.010) and varied with the origin of the patient, from 0.8% at a free and anonymous STI screening centre (CDAG) to 6% at STI clinics (CIDDIST). Out of 215 specimens analysed, 112 were confirmed by culture or with a second PCR-positive sample, and 103 were tested with the two other PCR assays. A total of 197/215 NG-positive Abbott PCR results were confirmed. The overall positive predictive value (PPV) of the CT/NG Abbott test was 91.6%, ranging from 73.5% for asymptomatic patients consulting at CDAG to 95.8% for symptomatic patients consulting at CIDDIST. Concern-

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ing the analytical sensitivity, the Cepheid test was 10 and 100 times more sensitive than the Abbott and the Roche tests, respectively.
In populations where the prevalence was < 1%, the Abbott CT/ NG test had a PPV < 90% and therefore required confirmation testing. When NG screening is associated with that of CT in populations with variable prevalence, it should be recommended to either use a NG PCR test with two targets or confirm a positive result by another PCR test with a different target. Background Proficiency materials are designed to resemble true clinical samples, yet challenges exist in procuring sufficient quantity of patient material. Simulated samples are often provided for this testing. Matrix effect with simulated samples can confound molecular assessment, having negative consequences for the laboratory through failed proficiency testing. This study was conducted to evaluate simulated urine samples provided for proficiency testing which generate invalid results with the cobas © CT/NG test. Methods Simulated urine proficiency panels were acquired from a commercial proficiency testing provider. Panels were evaluated in triplicate by routine procedure at neat concentrations and processed with cobas © PCR media at the following dilutions 1:1, 1:5, 1:10, 1:20, 1:50, 1:100, 1:200, and 1:500. The samples were held at room temperature (1 complete set) for 1 hour prior to loading on the cobas © 4800 system, while the second complete set of samples were processed 24 hours later. Samples were tested using two different cobas © 4800 workflows (400ul vs. 850ul of sample). Internal control and target Ct values were assessed for each sample to determine success of amplification. Results Invalid results due to internal control failures were observed at neat concentrations of simulated urine samples. Incubation of samples for 1 hour or 24 hours in cobas © PCR media, showed no significant difference between target and IC Ct values indicating incubation period in cobas © PCR media does not impact performance. Simulated Urine Sample dilution of 1:5 in cobas © PCR media using the 400ul sample input volume produced similar IC Ct values (mean Ct = 35.5) to cobas © PCR media tested alone (mean Ct = 36), and produced a robust target signal (mean Ct = 22). Conclusions Proficiency testing materials may require optimization for use on commercially available systems. Optimal processing of simulated urine specimens can be achieved by dilution in cobas © PCR media. Background Most women with endometriosis receive unnecessary antibiotics for "P.I.D." because both conditions present with pelvic pain and dyspareunia.
We used negative chlamydial antibody titre and laparoscopy to confirm diagnoses in women identified by dysmenorrhea symptom scoring (DSS) as more probably having endometriosis than PID.