TABLE 5.
Clinical evaluation of antigen detection for SARS-CoV
| Diagnostic method and detection target | Diagnostic gold standard | Collection time after onset of symptoms (days)a (no. of samples) | Sensitivity (%) | Overall specificity (%) | Reference |
|---|---|---|---|---|---|
| EIA | |||||
| N protein | WHO criteria, probable SARS | 3-5 (8) | 50 | 98.5 | 48 |
| 6-10 (14) | 71.4 | ||||
| 11-20 (9) | 44.4 | ||||
| N protein | WHO criteria, probable SARS | 1-5 (84) | 92.9 | 100 | 86 |
| 6-10 (63) | 69.8 | ||||
| 11-20 (52) | 30.8 | ||||
| N protein | WHO criteria, probable SARS | 1-5 (85) | 94 | 99.9 | 46 |
| 6-10 (60) | 78 | ||||
| N protein | WHO criteria, probable SARS | NM (18) | 100 | 100 | 127 |
| N protein | Laboratory confirmedb | 6-24 (66) (NPA) | 52 | 96.7 | 191 |
| 11-31 (94) (urine) | 5 | 99 | |||
| 8-32 (65) (stool) | 55 | 96 | |||
| Immunofluorescence assay | |||||
| N protein | WHO criteria, probable SARS | 2-9 (17) (throat wash) | 65 | 100 | 226 |
a
Serum samples collected unless specified. NM, not mentioned.
b
Positive for IgG antibodies against SARS-CoV by indirect immunofluorescence assay in serum sample during the course of illness.