Table 1.
Rates of “true” positivity of SARS-CoV-2 IgM and IgG antibodies in 64 patients with SARS-CoV-2 RT-PCR confirmed COVID-19 with serial blood samples (n = 104) collected at different time points from symptom onset.
| Symptom onset | n (%) | IgM | IgG | IgM or IgG |
|---|---|---|---|---|
| <5 (days) | 34 (100%) | −30 (88.2%) | −32 (94.2%) | −29 (85.3%) |
| ±2 (5.9%) | ±1 (2.9%) | ±2 (5.9%) | ||
| + 2 (5.9%) | + 1 (2.9%) | + 3 (8.8%) | ||
| 5–10 (days) | 35 (100%) | −19 (54.3%) | −22 (62.9%) | −17 (48.6%) |
| ±3 (8.6%) | ±0 (0%) | ±1 (2.8%) | ||
| + 13 (37.1%) | + 13 (37.1%) | + 17 (48.6%) | ||
| >10–15 (days) | 17 (100%) | −3 (17.6%) | −3 (17.6%) | −3 (17.6%) |
| ±1 (5.9%) | ±0 (0%) | ±0 (0%) | ||
| + 13 (76.4%) | + 14 (82.4%) | + 14 (82.4%) | ||
| >15–22 (days) | 18 (100%) | −1 (5.6%) | −0 (0%) | −0 (0%) |
| ±0 (0%) | ±0 (0%) | ±0 (0%) | ||
| + 17 (94.4%) | + 18 (100%) | + 18 (100%) |
- Negative (OD ≤ negative cutoff).
±Borderline (OD > negative cutoff but < positive cutoff).
+ Positive (OD ≥ positive cutoff).