Performance of Patient-collected Specimens for Neisseria gonorrhoeae Culture

Abstract

Background: Neisseria gonorrhoeae culture is necessary to determine antimicrobial resistance, but typically requires specimen collection by clinicians. We sought to determine the sensitivity of patient-collected specimens for N. gonorrhoeae culture.

Methods: We performed N. gonorrhoeae cultures on paired clinician- and patient-collected specimens from the pharynx (n = 93), rectum (n = 88), endocervix/vagina (n = 89), and urethra/urine (n = 46). We calculated the percent concordance and the kappa statistics for paired-specimen results, and determined the test sensitivity for each specimen type using positivity of either specimen in a pair as a gold standard defining the presence of true infection.

Results: At least 1 specimen was positive in 26%, 31%, 61%, and 3% of paired samples in the pharynx, rectum, urethra/urine, and endocervix/vagina, respectively. Patient- and clinician-collected results were highly concordant at the pharynx (95%; kappa = 0.85), rectum (99%; kappa = 0.97), urethra/urine (83%; kappa = 0.87), and endocervix/vagina (100%; kappa = 1.0; P ≤ .005 for all comparisons). Patient-collected pharyngeal and rectal swabs and urine were 92%, 96%, and 96% sensitive, while clinician-collected specimens at these anatomic sites were 87.5%, 100%, and 94% sensitive (P > .05 for all comparisons). Among 24 urine specimens held for 4-22 hours after collection, 100% yielded concordant N. gonorrhoeae culture results, compared to immediate processing.

Conclusions: Patient- and clinician-collected specimens are comparably sensitive for N. gonorrhoeae culture. These findings suggest that patient-collected specimens could be used to expand the availability of gonococcal antimicrobial resistance testing for both clinical and surveillance purposes.

Keywords: culture; gonorrhea; specimen collection.