Table 2 Evaluation of 49 patients (101 swabs) with discordant COVID-19 testing and confirmatory testing results
From: False negative rate of COVID-19 PCR testing: a discordant testing analysis
Swab 1 (n = 49 swabs) | Swab 2 (n = 49 swabs) | Swab 3 (n = 3 swabs)c | |
|---|---|---|---|
NP swab in UTM (%) | 29 (59.2) | 32 (65.3) | 2 (66.7) |
Deep nasal turbinate swab (%) | 20 (40.8) | 9 (18.4) | 1 (33.3) |
Oropharyngeal swab (%) | 0 | 8 (16.3) | 0 |
Original swab test resulta (E gene Ct median; range) (RdRp gene Ct median; range) | 49 negative | 46 positive 3 negative (19.5; 13.0–35.5) (22.4; 16.2–37.8) | 3 positive 0 negative (13.9; 12.5–24.7) (16.5; 14.8–28.0) |
Positive result on E gene assayb (Ct range) | 5/49 (34.1–37.9) | 0/3 | ND |
Positive result on CDC N1 assayb (Ct range) | 2/49 (32.7–35.9) | 0/3 | ND |
Positive result on CDC N2 assayb (Ct range) | 5/49 (33.2–38.8) | 0/3 | ND |