Table 2. Baseline characteristics of all participants, including previous symptoms, PCR testing, and antibody detection
Participant characteristicsTotal, n = 971Previous symptoms suggestive of SARS-CoV-2, n = 339Previous PCR nasopharyngeal swab for SARS-CoV-2, n = 139Either antibody test positive, n = 118
Age, years Mean SD Mean SD Mean SD Mean SD
53.017.249.815.451.713.650.315.8
Median Range Median Range Median Range Median Range
5518–975118–885320–845418–80
Sex Patients, n Patients, % Patients, n Patients, % Patients, n Patients, % Patients, n Patients, %
Male392401203550364639
Female579602196589647261
Participant type
1. Patient799822718093679883
2. Healthcare staff17218682046332017
2.1 Administration3441036422
2.2 Nursing515247161287
2.3 Doctor404144141043
2.4 Other healthcare staff47520610765
History PCR and symptoms
Previous PCR test for SARS-CoV-213914108321391004336
 Positive PCR test3324282633242763
Previous symptoms suggestive of SARS-CoV-233935108788370
Severity of symptoms
Mild112121123322162319
Moderate193201935770505244
Severe3443410161287
  • PCR = polymerase chain reaction. SD = standard deviation.