Value of a DNA probe assay (Gen-Probe) compared with that of culture for diagnosis of gonococcal infection

Abstract

The Gen-Probe PACE 2 system for Neisseria gonorrhoeae (GP), which uses a chemiluminescently labeled DNA probe, was compared with conventional culture as the method of reference. A total of 1,750 specimens were collected from 496 females and 623 males visiting the outpatient clinic of the Sexually Transmitted Diseases Department of the Westeinde Hospital, The Hague, The Netherlands, during the year 1991. The prevalences of gonorrhea culture-positive men and women were 14.9 and 7.7%o, respectively. The overall positive rate was 8.7%. Sensitivity, specificity, and positive and negative predictive values of GP were 97.1, 99.1, 90.6, and 99.8%, respectively. A total of 12 of 13 patients with positive GP results and negative cultures may have had a gonococcal infection, a conclusion based on clinical symptoms, positive methylene blue smears, and high relative light unit ratios. The DNA probe test can be useful as a suitable screening and diagnostic test for gonorrheal infection in men and women. An advantage of using this DNA probe technique is that simultaneous testing for Chlamydia trachomatis of the same specimen is possible. We also examined whether (all) rRNA had disappeared after adequate treatment for gonococcal and/or chlamydial infection in 30 patients. None of those positive patients showed a positive result in the DNA probe assay after treatment.

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

“…Falsepositive PACE 2 assay results with low RLU values have been observed in other studies (4,8,12,14,19). Some investigators have suggested that a borderline zone for retesting of lowvalue positive or high-value negative results be developed to help in the evaluation of these samples (4,8,9,19,23,24). In using the PACE 2C assay, an intermediate zone for low-value positive results may not be needed, since all positive samples are retested by single probes to identify the organism(s).…”

“…The major advantages of these probes, in addition to their performance characteristics, are the effective stabilization of patient specimens after collection and the ability to test for both C. trachomatis and N. gonorrhoeae with one specimen. This has proven useful, since a coinfection rate of 15 to 40% with these pathogens is not unusual (2,6,12,16,17,24).…”

Accuracy and interlaboratory reliability of human papillomavirus DNA testing by hybrid capture

“…A broad and important question raised by the present study, therefore, is how reliable and accurate a DNA diagnostic test must be before it is judged to be ready for widespread clinical use. The screening literature regarding DNA diagnostics is expanding (1,22), but few performance standards have been promulgated in the DNA diagnostics community on the basis of commonly used statistics such as percentages of agreement, sensitivity, and specificity. In particular, interlaboratory reliability has rarely been formally investigated and presented.…”

Gonorrhea in Prepubertal Children

“…No current data are available for the pediatric population, but studies of adults have shown a significant incidence of false-positive indirect tests compared with the incidence obtained by culture methods. 10,11 By law, all known cases of gonorrhea in children must be reported to the local health department. A report also should be made to a child protective services agency.…”