Background: Healthcare workers (HW) are a vulnerable group to develop burnout during the COVID-19 pandemic. The aims of this study were to evaluate the perception of HW about the antibody test, and, secondarily, the prevalence of burnout and factors associated with burnout among HW who took the test. Methods: In this cross-sectional study, we evaluated burnout among HW in a 600-bed building entirely dedicated to COVID-19 inpatients care at Hospital das Clinicas (HC), located in Sao Paulo, Brazil. The HW answered an online questionnaire that included questions on burnout, a single-item scale based on the Maslach Burnout Inventory; demographic data, professional category, type of Protective Personal Equipment (PPE) used, distancing from social support; and emotional reactions to their serology result. Bivariate and multivariate analyses were done to evaluate the risk of burnout. Outcomes: Among 4,417 HW tested, 528 (12.0%) were positive for SARS-CoV-2 and 1,945 answered the questionnaire. Burnout was reported by 308 (15.8%); anxiety, tenseness, and depression associated with COVID-19 were reported by 344 (17.7%); 292 (15.1%); and 181(9.3%) of the participants, respectively. The risk factors for burnout were: being a physician [adjOR:1.604;(95%CI 1.604-1.080;p=0.019)]; a physiotherapist [adjOR:2.047;(95%CI:1.285–3.261;p=0.003)]; perceiving a decrease in public safety[adjOR:1.983;(95%CI:1.229–3.199;p=0.005)]; anxiety [adjOR:2.721;(95%CI:1.812–4.085;p=
