Table 3.
Assay performance parameters of in-house ELISAs.
| Disease status defined by PCR | ||||
|---|---|---|---|---|
| Positive | Negative | |||
| RBD-IgG ELISA |
Positive | 35 | 0 | PPV = 35/35 = 100% |
| Negative | 15 | 50 | NPV = 50/65 = 76.9% | |
| SN = 35/50 = 70.0% | SP = 50/50 = 100% | |||
|
| ||||
| RBD-IgM ELISA |
Positive | 42 | 0 | PPV = 42/42 = 100% |
| Negative | 8 | 50 | NPV = 50/58 = 86.2% | |
| SN = 42/50 = 84.0% | SP = 50/50 = 100% | |||
|
| ||||
| RBD-IgG/IgM ELISA |
Positive | 42 | 0 | PPV = 42/42 = 100% |
| Negative | 8 | 50 | NPV = 50/58 = 86.2% | |
| SN = 42/50 = 84.0% | SP = 50/50 = 100% | |||
|
| ||||
| NC-IgG ELISA |
Positive | 44 | 0 | PPV = 44/44 = 100% |
| Negative | 6 | 50 | NPV = 50/56 = 89.3% | |
| SN = 44/50 = 88.0% | SP = 50/50 = 100% | |||
|
| ||||
| NC-IgM ELISA |
Positive | 41 | 0 | PPV = 41/41 = 100% |
| Negative | 9 | 50 | NPV = 50/59 = 84.7% | |
| SN = 41/50 = 82.0% | SP = 50/50 = 100% | |||
|
| ||||
| NC-IgG/IgM ELISA |
Positive | 46 | 0 | PPV = 46/46 = 100% |
| Negative | 4 | 50 | NPV = 50/54 = 92.6% | |
| SN = 46/50 = 92.0% | SP = 50/50 = 100% | |||
SN: sensitivity, SP: specificity, PPV: positive predictive value, and NPV: negative predictive value.