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Biomedical subjects

K L Warren

Publications and source records attributed to K L Warren.

4 recordsLinked to original sources

Effect of off-site transportation on detection of Neisseria gonorrhoeae in endocervical specimens.

OBJECTIVES: To evaluate both the effect of off-site transportation on detection of Neisseria gonorrhoeae in cultured endocervical specimens and the impact of transportation on viability of N. gonorrhoeae by comparison of culture with a nucleic acid probe assay. DESIGN: Three endocervical swabs were randomly collected; one was tested on-site using a nucleic acid-based assay (PACE 2NG System, Gen-Probe, Inc, San Diego, Calif), one was tested off-site following inoculation to modified Thayer-Martin agar (Remel, Lenexa, Kan), and a third swab was tested on-site by culture isolation. A nucleic acid amplification assay of the original swab for PACE 2NG testing was used to resolve discrepancies. SETTING: The emergency department of a university medical center. PATIENTS: Four hundred two patients were evaluated. The test population consisted of both asymptomatic and symptomatic patients. MAIN OUTCOME MEASURE: Positivity for N. gonorrhoeae by one or more of the test procedures, with discrepancy analysis when warranted. RESULTS: Of 402 specimens evaluated, the sensitivities for on-site and off-site testing using culture isolation for N. gonorrhoeae were 88.9% and 77.8%, respectively, in a population prevalence of 6.7%. However, the sensitivity for on-site PACE 2NG testing for N. gonorrhoeae was 96.3%. CONCLUSIONS: A decrease in sensitivity between on-site and off-site culture was found, which suggested transportation may have an adverse effect on the detection of N gonorrhoeae. However, with the limited population and prevalence, the difference was not found to be statistically significant. Further studies indicated that the nucleic acid probe assay was significantly more sensitive (P = .05) when compared with off-site testing using a culture isolation method, demonstrating that viability is an important consideration. These results suggested that a molecular probe assay should be considered in testing specimens for N. gonorrhoeae, especially when the specimen is to be transported off-site.

Bacteriological Techniques↗

Evaluation of nucleic acid-based test (PACE 2C) for simultaneous detection of Chlamydia trachomatis and Neisseria gonorrhoeae in endocervical specimens.

A nucleic acid-based test (Gen-Probe PACE 2C System) was evaluated for the ability to detect Chlamydia trachomatis and Neisseria gonorrhoeae from endocervical specimens in a single assay. Three swab samples, randomized for collection order, were obtained from each patient and tested by N. gonorrhoeae and C. trachomatis culture and by the PACE 2C probe assay. Fifty of 395 specimens were culture positive for N. gonorrhoeae (17 specimens), C. trachomatis (26 specimens), or both (7 specimens), of which PACE 2C testing detected 48 specimens. The PACE 2C assay was positive for 56 specimens, including 8 specimens not positive by culture. Of the total of 10 discrepancies between culture and PACE 2C results, resolution testing yielded four false-negative culture, four false-positive PACE 2C, and two false-negative PACE 2C results. The sensitivity, specificity, and positive and negative predictive values for PACE 2C after reevaluation were 96.3, 98.8, 92.9 and 99.4%, respectively. The overall sensitivities for C. trachomatis and N. gonorrhoeae culture were 89.2 and 88.9%, respectively. The prevalence rate for C. trachomatis was 9.4%, and that for N. gonorrhoeae was 6.8%. The Gen-Probe PACE 2C System is a reliable alternative for screening endocervical specimens for both C. trachomatis and N. gonorrhoeae in a single assay.

Cervix Uteri↗