COVID-19 IgG and IgM values among previously undiagnosed HCWs working in four hospitals
| FJD | HGV | HUIE | HURJC | Total | |
| n (%) | n (%) | n (%) | n (%) | N (%) | |
| Total | 3091 | 699 | 723 | 1482 | 5995 |
| IgM (+) IgG (+) | 103 (3.33) | 7 (1.00) | 32 (4.43) | 30 (2.02) | 172 (2.86) |
| IgM (+) IgG (−) | 51 (1.65) | 2 (0.29) | 17 (2.35) | 19 (1.28) | 89 (1.48) |
| IgM (−) IgG (+) | 363 (11.64) | 64 (9.16) | 103 (14.25) | 181 (12.21) | 711 (11.86) |
| IgM (−) IgG (−) | 2574 (83.27) | 626 (89.56) | 571 (78.98) | 1252 (84.48) | 5023 (83.79) |
FJD, Fundación Jiménez Díaz; HGV, Hospital General de Villalba; HUIE, Infanta Elena University Hospital; HURJC, Rey Juan Carlos University Hospital.