Table 3.
Positive and negative predictive values of serological testing for IgM+ or IgG+.
| Category | PPV5 | PPV10 | PPV20 | NPV5 | NPV10 | NPV20 |
|---|---|---|---|---|---|---|
| Overall | 67.52% | 81.44% | 90.80% | 98.88% | 97.67% | 94.92% |
| Days 0–7 | 40.63% | 59.09% | 76.47% | 96.80% | 93.47% | 86.41% |
| Days 8–14 | 66.67% | 80.85% | 90.48% | 98.73% | 97.35% | 94.23% |
| >14 days | 70.99% | 80.85% | 90.48% | 99.63% | 99.21% | 98.25% |
| CLIA | 81.90% | 90.53% | 95.56% | 99.26% | 98.45% | 96.59% |
| ELISA | 81.37% | 90.22% | 95.40% | 99.10% | 98.13% | 95.88% |
| LFIA | 56.82% | 73.53% | 86.21% | 98.66% | 97.22% | 93.95% |
| N antigen | 58.09% | 74.53% | 86.81% | 98.87% | 97.65% | 94.87% |
| S antigen | 82.57% | 90.91% | 95.74% | 99.47% | 98.89% | 97.54% |
| N and S antigen | 69.84% | 83.02% | 91.67% | 99.36% | 98.66% | 97.03% |
PPV5, positive predictive value at a prevalence of 5%; PPV10, positive predictive value at a prevalence of 10%; PPV20, positive predictive value at a prevalence of 20%; NPV5, negative predictive value at a prevalence of 5%; NPV10, negative predictive value at a prevalence of 10%; NPV20, negative predictive value at a prevalence of 20%; overall, without stratification by detection time; CLIA, chemiluminescence immunoassay; ELISA, enzyme-linked immunosorbent assay; LFIA, lateral flow immunosorbent assay.