ENZYME-IMMUNOASSAY FOR DIAGNOSIS OF GONORRHEA

An enzyme immunoassay (EIA; Gonozyme) for gonococcal antigen was assessed for the rapid diagnosis of gonorrhea. Patients attending 2 sexually transmitted disease clinics were tested by EIA and culture on Thayer-Martin medium. EIA was highly effective in detecting gonococcal infection among symptomatic men, with 70 of 75 (93.3%) culture-positive men having positive tests and no false-positive reactions. The performance of the test was not as good in detecting cervical gonorrhea; the best result obtained was a sensitivity of 87% (33 of 38) for EIA compared with culture. EIA false-positives occurred at a relatively low rate for women, with the test having a specificity of .apprx. 97%. The test clearly detected gonococcal antigen in cervical and urethral specimens; its role in routine diagnosis is not clear. Its performance seems equal to that of the Gram stain for men; it seems to be less sensitive than culture for cervical gonorrhea, a drawback in high-risk populations. The low false-positive rate could be an important issue in screening low-prevalence populations.