Table 4 Comparative evaluation of FDA-EUA versus COVAM serology by symptom characteristics
| Â | Symptom characteristics by serology assay | Percent seropositive within each symptom category | ||||
|---|---|---|---|---|---|---|
FDA-EUA assay or microarray | N (%) of FDA-EUA serology with characteristic | N (%) of COVAM serology with characteristic | p value | N (%) of characteristic with positive FDA-EUA serology | N (%) of characteristic with positive COVAM serology | |
Seropositive—total | 87 | 53 | 78 |  < 0.01 | 60.9% | 89.7% |
Reported to occupational health | 67 (77.0) | 46 (86.8) | 63 (80.8) | NS | 68.7% | 94.0% |
Any symptom reported | 62 (71.3) | 42 (79.2) | 58 (74.4) | NS | 67.7% | 93.5% |
No symptom reported | 25 (28.7) | 11 (20.8) | 20 (25.6) | NS | 44.0% | 80.0% |
Symptom type | ||||||
 Non febrile illness | 19 (21.8) | 8 (15.1) | 16 (20.5) | NS | 42.1% | 84.2% |
 Fever | 43 (49.4) | 34 (64.2) | 42 (53.8) | NS | 79.1% | 97.7% |
 Fatigue | 49 (56.3) | 35 (66.0) | 46 (59.0) | NS | 71.4% | 93.9% |
 Chills | 46 (52.9) | 34 (64.2) | 43 (55.1) | NS | 73.9% | 93.5% |
 Myalgia | 47 (54.0) | 33 (62.3) | 45 (57.7) | NS | 70.2% | 95.7% |
 Congestion | 42 (48.3) | 25 (47.2) | 39 (50.0) | NS | 59.5% | 92.9% |
 Cough | 37 (42.5) | 28 (52.8) | 34 (43.6) | NS | 75.7% | 91.9% |
 Loss of smell | 30 (34.5) | 28 (52.8) | 30 (38.5) | NS | 93.3% | 100.0% |
 Shortness of breath | 21 (24.1) | 16 (30.2) | 19 (24.4) | NS | 76.2% | 96.3% |
Days between symptoms and serology sample collection | Â | Â | Â | NS | Â | Â |
 < 14 days | 4 (4.6) | 3 (5.7) | 4 (5.1) |  | 75.0% | 100.0% |
 15–29 days | 10 (11.5) | 8 (15.1) | 9 (11.5) |  | 80.0% | 90.0% |
 30–44 days | 7 (8.0) | 7 (13.2) | 7 (9.0) |  | 100.0% | 100.0% |
 45–59 days | 23 (26.4) | 19 (35.8) | 23 (29.5) |  | 82.6% | 100.0% |
 60–74 days | 2 (2.3) | 1 (1.9) | 2 (2.6) |  | 50.0% | 100.0% |
 ≥ 75 days | 15 (17.2) | 4 (7.5) | 12 (15.4) |  | 26.7% | 80.0% |