Antigen detection for the diagnosis of gonorrhea

Abstract

We compared the diagnostic value of an enzyme immunoassay method for detection of gonococcal antigen in genital secretions with culture results and direct Gram stain for Neisseria gonorrhoeae in 1,171 men and 723 women attending a sexually transmitted disease clinic. When compared with culture results in men, the immunoassay provided a sensitivity of 94% and a specificity of 98% and was essentially equivalent to the urethral Gram stain. The predictive value of a positive immunoassay was 97% in men with a urethral discharge in whom the prevalence of gonorrhea was 36%, and 30% in men without urethral discharge, who had a 2% prevalence of gonorrhea (P less than 0.001). The sensitivity of the immunoassay was 95% in men with and 67% in men without urethral discharge (P less than 0.01). In women, the immunoassay resulted in a sensitivity of 78% and a specificity of 98% compared with cervical culture and had a significantly better sensitivity than the cervical Gram stain (78 versus 48%, P less than 0.001). Analysis of patients with discrepant culture and immunoassay results suggested that most culture-negative, immunoassay-positive patients probably did not have gonorrhea. After treatment, all but 1 of 59 originally culture- and immunoassay-positive patients became negative in both tests by 3 days. Results of the immunoassay were not affected by transport or by refrigeration for up to 30 days.

Evaluation of Gonozyme, an enzyme immunoassay for the rapid diagnosis of gonorrhea

“…In males, the sensitivity and specificity of EIA were comparable with those of Gram stain, whereas in females, EIA was more sensitive though less specific than Gram stain. These findings are similar to those of other published evaluations of Gonozyme (1,6,11,22,24,26). It should be pointed out that at the time of our clinical study there was only one Gonozyme test available for evaluation.…”

“…For all males and females studied by Aardoom et al 1, the specificity of Gonozyme was 95.1%, whereas for patients examined after treatment, the specificity was 94.7%. Stamm et al report that all 39 patients seen for test of cure 3 to 17 days after treatment had negative culture and EIA results (26). Based on these observations, we conclude that Gonozyme does not appear to detect residual nonviable gonococci on urogenital swabs from patients who had received treatment for gonorrhea 1 to 2 weeks earlier and are seen for test of cure.…”

Evaluation of a prototype DNA probe test for the noncultural diagnosis of gonorrhea

“…One commercially available enzyme immunoassay system for the direct detection of gonococci in clinical material, called Gonozyme (Abbott Laboratories, North Chicago, 111. ), has been reported to give good correlation with culture results (1,3,6,11,21,26,27).…”

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

“…Successful culture requires organism viability and timely transport under stringent conditions to the laboratory for processing. Even under these conditions, the sensitivity is reported to be only 85 to 95% (13). DNA hybridization technology provides an alternative identification method that offers rapid (2-h) results, as well as ease of specimen storage and transportation (9).…”