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

Arch Pathol Lab Med. 1996 Nov;120(11):1019-22.


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.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Bacteriological Techniques / statistics & numerical data
  • Female
  • Gonorrhea / diagnosis*
  • Humans
  • Molecular Probe Techniques / statistics & numerical data
  • Neisseria gonorrhoeae / genetics
  • Neisseria gonorrhoeae / isolation & purification*
  • Outcome Assessment, Health Care
  • Sensitivity and Specificity
  • Specimen Handling / methods*
  • Transportation
  • Vaginal Smears / methods*