Detection of Neisseria gonorrhoeae in cervical swabs using the Gonozyme enzyme immunoassay. Clinical evaluation in a university family planning clinic

Abstract

The authors performed a prospective clinical evaluation of the Gonozyme (Abbott Laboratories, Chicago, IL) assay in a family planning clinic population. One thousand five hundred eighty-eight female patients were screened for gonococcal infection using culture and Gonozyme assay. One hundred nine patients were culture positive (6.9% disease prevalence). The sensitivity and specificity of the Gonozyme assay in this setting was 87.2% and 89.1%, respectively. The predictive value of a positive and negative test, given a disease prevalence of 6.9%, was 37.2% and 98.9%, respectively. The false-positive and false-negative rate was 10.9% and 12.8%, respectively. The authors prospectively followed patients with true-positive and false-positive Gonozyme results. The Gonozyme test showed a 83% correlation with test of cure cultures and, thus, should not be used for test cure analysis. False-positive Gonozyme tests could not be explained on the basis of cross-reacting bacteria or detection of vancomycin-sensitive gonococci. The authors' results suggest that the Gonozyme test should not be used in lieu of culture in a clinical setting with a similar population.

PIP: The authors performed a prospective, clinical evaluation of the Gonozyme assay in a family planning clinic population. 1588 female patients were screened for gonococcal infection using culture and Gonozyme assay. 109 patients were culture positive (6.9% disease prevalence). The sensitivity and specificity of the Gonozyme assay in this setting was 87.2% and 89.1% respectively. The predictive value of a positive and negative test, given a disease prevalence of 6.9%, was 37.2% and 98.9%, respectively. The false positive and false negative rate was 10.9% and 12.8% respectively. The authors prospectively followed patients with true positive and false positive Gonozyme results. The Gonozyme test showed an 83% correlation with test of cure cultures and, thus, should not be used for test of cure analysis. False positive Gonozyme tests could not be explained on the basis of cross-reacting bacteria or detection of vancomycin sensitive gonococci. Results suggest that the Gonozyme test should not be used in lieu of culture in a clinical setting with a similar population.