Evaluation of Self-Collection as a Method of Extragenital STI Screening

Abstract

Introduction: The goal of this study is to improve overall screening, detection, and treatment of Neisseria gonorrhea (GC) and Chlamydia trachomatis (CT) at our institution.

Materials and methods: An observational study with two phases was conducted at a U.S. Army Medical Center. Previously collected samples from January 2014 through December 2015 were compared to prospectively collected data from March 2016 through December 2017. All data were collected from a convenience sample of active duty, HIV-positive men who have sex with men. Concordance between provider-collected and self-collected extragenital screening (EGS) samples was evaluated.

Results: The rate of detection using EGS was higher than previously found using urogenital screening alone. Our prospective analysis revealed that expanding screening to include extragenital sites increased rates of detection of GC and CT. Our rates of GC detection at the pharynx and rectum, and CT detection at the rectum, were higher than those reported in the literature for men who have sex with men. Rates of CT infection at the pharynx were comparable with those reported in the literature. Detection of GC at the pharynx was exactly concordant between self-collected and provider-collected samples. Concordance of GC and CT detection at the rectum was very good. The kappa coefficient for detection of CT at the pharynx was zero, which corresponded to 44 out of 45 concordant observations.

Conclusions: Prior to implementation of EGS at our institution, we missed the opportunity to detect a substantial number of GC/CT infections with urogenital screening alone. Our results suggest that self-collection is a reliable method of EGS as compared to provider collection of samples.