COVID-19(24) occupational health(15) public health(13) Infection(10) Epidemiology(10) Prevalence(10) SARS-CoV-2(10) SARS-COV-2 infection(10) SARS-CoV-2 antibody(10) reported(10) public health surveillance.(9) healthcare(9) age(9) Protective(9) public health.(8) Health(8) 95% CI(8) risk(7) was used(7) antibody(7) Risk factors(7) significant difference(7) association(7) IgG(7) Seroprevalence(7) equipment(7) estimate(7) variable(7) the SARS-CoV-2(7) cross-sectional(7)