Table 2.
Broad characteristics among healthcare workers (HCWs) with positive antibody reactivity to SARS-CoV-2 spike in both phases
| Overall | Asymptomatic for SARS-CoV-2 infection | Symptomatic for SARS-CoV-2 infection | P value | |
| n=68 | n=11 | n=57 | ||
| Age, mean (±SD) | 42.9 (±1.45) | 44.5 (±3.8) | 42.6 (±1.6) | 0.557 |
| Female, n (%) | 40 (58.8) | 6 (54.5) | 34 (40.4) | 0.502 |
| Race | 0.753 | |||
| Latinx | 21 (30.9%) | 3 (27.3%) | 18 (31.6%) | |
| Asian | 18 (26.5%) | 3 (27.3%) | 18 (26.3%) | |
| Black | 15 (22.1%) | 3 (27.3%) | 12 (21.1%) | |
| White | 10 (14.7%) | 2 (18.2%) | 8 (14.0%) | |
| Other | 4 (5.8%) | 0 (0%) | 4 (7.0%) | |
| Comorbidities | ||||
| Hypertension | 13 (19.1%) | 2 (18.2%) | 11 (19.3%) | 0.650 |
| Diabetes | 6 (8.8%) | 0 (0%) | 6 (10.5%) | 0.332 |
| COPD and asthma | 13 (19.1%) | 1 (9.1%) | 12 (21.1%) | 0.326 |
| Number of symptoms, median (IQR) | – | – | 4.0 (2.0–5.0) | |
| Length of symptoms | ||||
| <7 days | – | – | 19 (33.3%) | |
| 7–14 days | – | – | 12 (21.1%) | |
| >14 days | – | – | 26 (45.6%) | |
| Degree of HCW exposure | 0.492 | |||
| High and moderate | 16 (23.5%) | 2 (18.2%) | 14 (24.6%) | |
| Minor | 52 (76.5%) | 9 (81.8%) | 43 (75.4%) | |
| Community exposure | 19 (27.9%) | 3 (27.3%) | 16 (28.1%) | 0.635 |
| Household exposure | 17 (25.4%) | 3 (27.3%) | 14 (24.6%) | 0.557 |
| Use of face mask outside of hospital | 58 (85.3%) | 9 (81.8%) | 49 (86.0%) | 0.722 |
| Principal means of transportation | 0.663 | |||
| Public | 33 (48.5%) | 6 (54.5%) | 27 (47.7%) | |
| Private | 35 (51.5%) | 5 (45.5%) | 30 (52.6%) | |
| Nature of work | 0.502 | |||
| Physician | 29 (42.6%) | 4 (36.4%) | 25 (43.9%) | |
| Nurse | 15 (22.1%) | 2 (18.2%) | 13 (22.8%) | |
| Other | 24 (35.3%) | 5 (45.5%) | 19 (33.3%) | |
| Hospital areas work in | 0.288 | |||
| Emergency department/inpatient units | 32 (47.1%) | 6 (54.5%) | 26 (45.6%) | |
| Ambulatory care/clinics | 9 (13.2%) | 2 (18.2%) | 7 (12.3%) | |
| Inpatient and outpatient setting | 18 (26.5%) | 3 (27.3%) | 15 (26.3%) | |
| Administration/non-clinical care areas | 9 (13.2%) | 0 (0%) | 9 (15.8%) | |
| Anti-spike reactivity (AUC) | ||||
| Reactivity in phase 1, g-mean (IQR) | 6590 (5165–8410) | 5803 (2825–11 920) | 6754 (5177–8812) | 0.647 |
| Days from symptoms to first test, mean (±SD) | – | – | 47.7 (±1.9) | |
| Reactivity in phase 2, g-mean (IQR) | 2226 (1824–2718) | 2382 (1494–3797) | 2198 (1753–2755) | 0.980 |
| Days from symptoms to second test | 174.5 (±4.1) | |||
| Rate of decay, g-mean (IQR) | 31.14 (22.11–43.87) | 23.42 (8.45–64.93) | 32.96 (22.73–47.82) | 0.382 |
Continuous variables are expressed as mean (SD) or IQR, categorical variables as n (%).
AUC, area under the curve; COPD, chronic obstructive pulmonary disease; g-mean, geometric mean.