SARS-CoV-2(17) COVID-19(17) healthcare worker(9) positive(9) age(8) occupational medicine(8) coronavirus(8) antibody(8) Seropositivity(8) Infection(8) COVID-19 infection(8) conducted(7) Healthcare workers(6) COVID-19 symptoms(6) vaccination(6) participant(6) Coronavirus disease 2019(5) mental health(5) healthcare(5) SARS-COV-2 infection(4) was performed(4) serological assays(4) 95% CI(4) past(4) severe acute respiratory syndrome Coronavirus(4) the SARS-CoV-2(4) serology test(4) serological survey(4) SARS-CoV-2 antibody(4) performed(4)