Self-obtained vaginal swabs are not inferior to provider-performed endocervical sampling for emergency department diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis

Abstract

Objective: Provider-performed endocervical sampling (PPES) in the diagnosis of Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) may be difficult to perform in a busy emergency department (ED) due to patient preference, availability of the pelvic examination room, or provider availability. Our objective was to assess if self-obtained vaginal swabs (SOVS) were noninferior to PPES in the ED diagnosis of NG/CT using a rapid nucleic acid amplification test (NAAT).

Methods: We conducted a prospective observational cohort study in a single ED. Participants were adult female English- and Spanish-speaking patients in whom the ED provider felt that NG/CT testing was warranted. Each patient had SOVS and PPES performed. For SOVS, a research associate reviewed a one-page handout describing the procedure but gave no other assistance. Patients answered survey questions regarding acceptability of SOVS and symptomatology. We established a minimum sensitivity of 90% for SOVS to be considered clinically noninferior to standard PPES.

Results: A total of 533 patients completed enrollment and answered survey questions, 515 of whom had laboratory results for both SOVS and PPES. There were 86 patients with a positive result: 29 with NG, 47 with CT, and 10 with coinfection. SOVS had a sensitivity of 95% (95% confidence interval = 88% to 99%) for the detection of NG/CT when compared to PPES. SOVS were felt to be an acceptable collection method in 93% of patients and 75% preferred SOVS to PPES.

Conclusion: SOVS are noninferior to PPES in NG/CT diagnosis using a rapid NAAT in ED patients and surveys indicate high patient acceptability.

Keywords: Chlamydia trachomatis; Neisseria gonorrhoeae; Cepheid Xpert; endocervical sampling; nucleic acid amplification test; self-obtained vaginal swab.