COVID-19 seropositivity according to public transportation use
| Levels | HCWs in the sample | Seropositive HCWs | % positivity (95% CI) | P value* |
| Frequency (number of travels per week) of public transport for work (total N=1081) | ||||
| 1 | 104 | 8 | 7.7 (3.4 to 14.6) | 0.062 |
| 2 | 135 | 13 | 9.6 (5.2 to 15.9) | |
| 3 | 148 | 15 | 10.1 (5.8 to 16.2) | |
| 4 | 199 | 24 | 12.1 (7.9 to 17.4) | |
| 5 | 275 | 39 | 14.2 (10.3 to 18.9) | |
| >5 | 220 | 13 | 5.9 (3.2 to 9.9) | |
| Use of face mask at public transport (total N=1081) | ||||
| Yes | 151 | 8 | 5.3 (2.3 to 10.2) | |
| No/sometimes | 930 | 104 | 11.2 (9.2 to 13.4) | 0.030 |
*Fisher’s exact test.
HCWs, healthcare workers.