Assessment of Oropharyngeal Specimens for Discontinuation of Transmission-Based COVID-19 Precautions

Open Forum Infect Dis. 2020 Aug 26;7(9):ofaa382. doi: 10.1093/ofid/ofaa382. eCollection 2020 Sep.

Abstract

We compared oropharyngeal swab test performance with nasopharyngeal testing for discontinuation of transmission-based COVID-19 precautions. We performed a retrospective review of confirmed COVID-19-positive patients who received paired nasopharyngeal and oropharyngeal SARS-CoV-2 tests for clearance from isolation from May 4, 2020, to May 26, 2020. Using nasopharyngeal swabs as the reference standard, we calculated the sensitivity, specificity, and negative predictive value of oropharyngeal swabs. We also calculated the kappa between the 2 tests. A total of 189 paired samples were collected from 74 patients. Oropharyngeal swab sensitivity was 38%, specificity was 87%, and negative predictive value was 70%. The kappa was 0.25. Our study suggests that oropharyngeal swabs are inferior to nasopharyngeal swabs for test-based clearance from COVID-19 isolation.

Keywords: COVID-19; coronavirus PCR; discharge strategies; oropharyngeal swabs; residential substance use treatment; transmission-based precautions.