Rapid presumptive diagnosis of gonococcal urethritis in men by the limulus lysate test.

In an evaluation of the limulus assay as a method for detecting endotoxin in urethral exudates, positive results of urethral samples at a 1/200 dilution were obtained from 73 out of 73 patients with culture-positive gonococcal urethritis while negative results were obtained from 26 out of 27 patients with cuture-negative urethral specimens. A specimen from one patient, which gave negative results on Gram stain and culture, gave positive results to the limulus test. The overall accuracy of the limulus test for predicting culture results was 99% (p less than 0.001). Thus, in preliminary studies of otherwise healthy men, the results of the limulus assay correlated with those of biological methods for diagnosing urethral gonorrhoea; the test may, therefore, be of use in identifying cases of nongonococcal urethritis.