TABLE 3.
Comparison between the COVID-19-RdRp/Hel and RdRp-P2 real-time RT-PCR assays for the detection of SARS-CoV-2 RNA in different types of clinical specimens from 15 patients with laboratory-confirmed COVID-19
| Specimen typea | No. of positive test results/no. of specimens (%) |
P valueb | Mean (range) viral load (RNA copies/ml) in RdRp-P2-negative but COVID-19-RdRp/Hel-positive specimensc | |
|---|---|---|---|---|
| COVID-19-RdRp/Hel | RdRp-P2 | |||
| Respiratory tract | 102/120 (85.0) | 73/120 (60.8) | <0.001 | 4.33 × 104 (2.85 × 103−4.71 × 105) |
| NPA/NPS/TS | 30/34 (88.2) | 22/34 (64.7) | 0.043 | 1.74 × 104 (2.85 × 103−8.40 × 104) |
| Saliva | 59/72 (81.9) | 38/72 (52.8) | <0.001 | 5.32 × 104 (1.74 × 103−4.71 × 105) |
| Sputum | 13/14 (92.9) | 13/14 (92.9) | NS | NA |
| Non-respiratory tract | 17/153 (11.1) | 4/153 (2.6) | 0.005 | 7.06 × 103 (2.21 × 102−1.67 × 104) |
| Plasma | 10/87 (11.5) | 0/87 (0.0) | 0.001 | 7.86 × 103 (2.21 × 102−1.67 × 104) |
| Urine | 0/33 (0.0) | 0/33 (0.0) | NS | NA |
| Feces/rectal swabs | 7/33 (21.2) | 4/33 (12.1) | NS | 4.38 × 103 (1.54 × 103−6.69 × 103) |
| Total | 119/273 (43.6) | 77/273 (28.2) | <0.001 | 3.21 × 104 (2.21 × 102−4.71 × 105) |
a
Abbreviations: NPA, nasopharyngeal aspirate; NPS, nasopharyngeal swab; TS, throat swab.
b
NS, not significant.
c
NA, not applicable.