Table 1.
Serologic assessments augmented qPCR findings in describing individual SARS-CoV-2 infection status. The proportion of positive antibody test results compared to the qPCR result for each test. “All assay” shows the number of samples with a positive result from any of the eight antibody tests. Serologic screening identified 29 individuals that were qPCR negative that had previously been exposed to virus, and 11 individuals were positive for qPCR but seronegative, presumably tested prior to seroconversion. Positive and negative predictive for the positive result from any test was 55% (35/64) and 90% (111/122) [15].
| All Serological Assays Compared to qPCR | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| qPCR | Antibody | |||||||||
| Positive | Negative | |||||||||
| Positive | 35 | 11 | ||||||||
| Negative | 29 | 111 | ||||||||
| Individual Assays Compared to qPCR | ||||||||||
| Cellex | Abbott | ELISA RBD | RIA RBD | ELISA Spike | RIA Spike | ELISA NP | RIA NP | Any test | ||
| qPCR | Positive | 0.57 (26/46) | 0.73 (33/45) | 0.63 (29/46) | 0.70 (32/46) | 0.39 (18/46) | 0.24 (11/46) | 0.11 (5/46) | 0.20 (9/46) | 0.76 (35/45) |
| Negative | 0.08 (11/139) | 0.08 (10/132) | 0.16 (22/140) | 0.08 (11/133) | 0.14 (20/140) | 0.05 (7/140) | 0.03 (4/140) | 0.04 (5/140) | 0.21 (29/140) |
|