Table 2.
Case–control study of demographic and clinical features of patients with SARS-CoV-2–negative and –positive IgG antibodies
| SARS-CoV-2 seronegative population (n = 211) | SARS-CoV-2 seropositive population (n = 148) | Crude OR (95% CI) | P-value | Adjusted OR (95% CI)† | P-value† | |
|---|---|---|---|---|---|---|
| Age (years) | 0.9 (1.09–1.0) | 0.58 | 1 (0.9–1.0) | 0.87 | ||
| Gender | 0.01 | 0.08 | ||||
| Men | 119 (56.4%) | 63 (42.6%) | 0.6 (0.4–0.9) | 0.6 (0.4–1.0) | ||
| Women | 92 (43.6%) | 85 (57.4%) | 1 | 1 | ||
| Comorbidities | 0.63 | 0.52 | ||||
| Yes | 14 (6.6%) | 8 (5.4%) | 0.8 (0.3–2.0) | 0.7 (0.2–2.0) | ||
| No | 197 (93.4%) | 140 (94.6%) | 1 | 1 | ||
| Type of work | 0.05* | 0.33* | ||||
| Administrative staff | 19 (9.0%) | 17 (11.5%) | 1 | 1 | ||
| Cleaning staff and stretcher-bearers | 55 (26.1%) | 19 (12.8%) | 0.4 (0.2–0.9) | 0.5 (0.2–1.3) | ||
| Laboratory | 6 (2.8%) | 6 (4.0%) | 1.1 (0.3–4.1) | 1.0 (0.2–4.3) | ||
| Paramedical staff | 58 (27.5%) | 43 (29.0%) | 0.8 (0.4–1.8) | 0.8 (0.4–1.9) | ||
| Nurse | 41 (19.4%) | 42 (28.4%) | 1.1 (0.5–2.5) | 1.2 (0.5–2.8) | ||
| Physician | 32 (15.2%) | 21 (14.2%) | 0.7 (0.3–1.7) | 0.7 (0.3–1.8) | ||
| Use of personal protective equipment | 0.69* | 0.59* | ||||
| Full | 71 (33.6%) | 48 (32.4%) | 1 | 1 | ||
| Not full | 138 (65.4%) | 97 (65.5%) | 1.0 (0.7–1.6) | 1.3 (0.7–2.2) | ||
| No | 2 (0.9%) | 3 (2.0%) | 2.2 (0.3–13.8) | 2.0 (0.3–13.8) | ||
| Contact with a confirmed case | 0.06 | 0.69 | ||||
| Yes | 106 (50.2%) | 89 (60.1%) | 1.5 (0.9–2.3) | 1.1 (0.7–1.9) | ||
| No | 105 (49.8%) | 59 (39.9%) | 1 | 1 | ||
| WHO COVID-19 case definition | < 0.001 | < 0.001 | ||||
| Yes | 11 (5.2%) | 33 (22.3%) | 5.2 (2.5–10.7) | 5.1 (2.3–11.0) | ||
| No | 200 (94.8%) | 115 (77.7%) | 1 | 1 |
OR = odds ratio.
*
P-value by Wald test.
†
Each OR and P-value are adjusted for all other variables in the (logistic regression).