Table 3.
Sensitivity of rapid antigen tests for different types of clinical specimen.
| Clinical Specimen | Number of Samples | RT-qPCR | Standard Q COVID-19 Ag | Espline SARS-CoV-2 | QuickNavi COVID19 Ag | ImmunoAce SARS-CoV-2 | Virus Isolation |
|---|---|---|---|---|---|---|---|
| (Cq Value) | |||||||
| Gargle lavage | 7 | 26.3–36.0 | 0 a | 0 | 0 | 0 | 0 b |
| Saliva | 27 | 18.8–33.0 | 10 | 12 | 5 | 13 | 12 |
| T Swab | 2 | 25.8c, 33.6 | 0 | 0 | 0 | 0 | 1 |
| Nasal vestibule swab | 1 | 34.8 | 0 | 0 | 0 | 0 | 0 |
| N swab | 18 | 19.7-33.0 | 8 | 8 | 3.5 | 7 | 10 |
| Sputum | 4 | 19.9-34.3 | 1 | 1 | 1 | 1 | 0 |
| Tracheal aspirate | 17 | 19.6-35.6 | 7 | 6.5 | 5.5 | 3.5 | 1 |
a Each specimen was tested in two independent experiments; when a kit identified a sample as positive in both tests, a value of 1 was assigned. If only one test was positive, a value of 0.5 was assigned. If both tests were negative, a value of 0 was assigned. b Number of samples from which virus was isolated. c Virus was isolated from this specimen.