Comparison of Transgrow and Gonozyme for the detection of Neisseria gonorrhoeae in mailed specimens

Abstract

The Transgrow culture system and Gonozyme, an enzyme-linked immunosorbent assay, were compared by examining 510 patients (320 females, 190 males) from whom duplicate genital swabs were obtained for the diagnosis of N. gonorrhoeae infection. Transgrow and the Gonozyme swabs were mailed to the laboratory. Clinical, epidemiological and laboratory data for the 30 specimens for which there were discrepancies were evaluated to determine the probability of gonorrhea. At the same time, Gonozyme was compared to on-site Thayer-Martin cultures from 258 of the 510 patients, with a 93% agreement. When sensitivity and specificity were calculated on the basis of clinical, epidemiological and on-site laboratory data, Gonozyme had a sensitivity of 95% and a specificity of 99%. Transgrow culture was considered to have a 100% specificity and a sensitivity of 69%. Gonozyme appeared to be a superior method for the diagnosis of gonorrhea by means of mailed specimens.