Performance of Oropharyngeal Swab Testing Compared With Nasopharyngeal Swab Testing for Diagnosis of Coronavirus Disease 2019-United States, January 2020-February 2020

Among 146 nasopharyngeal (NP) and oropharyngeal (OP) swab pairs collected <= 7 days after illness onset, Real-Time Reverse Transcriptase Polymerase Chain Reaction assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 RT-PCR) diagnostic results were 95.2% concordant. However, NP swab cycle threshold values were lower (indicating more virus) in 66.7% of concordant-positive pairs, suggesting NP swabs may more accurately detect the amount of SARS-CoV-2.

Automated summary

Among 146 pairs of nasopharyngeal and oropharyngeal swabs collected within 7 days after illness onset, Real-Time Reverse Transcriptase Polymerase Chain Reaction assay for SARS-CoV-2 showed a 95.2% concordance rate. However, in concordant-positive pairs, lower cycle threshold values were observed in nasopharyngeal swabs in 66.7% of cases, suggesting they may more accurately detect the amount of SARS-CoV-2.