Review Seroprevalence of SARS-CoV-2 antibodies and associated factors in healthcare workers: a systematic review and meta-analysis

Background: Healthcare workers (HCWs) represent a high-risk population for infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Aim: To determine the seroprevalence of SARS-CoV-2 antibodies among HCWs, and identify the factors associated with this seroprevalence. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were applied for this systematic review and meta-analysis. Databases including PubMed/MEDLINE and preprint services (medRciv and bioRciv) were searched from inception to 24th August 2020. Findings: Forty-nine studies including 127,480 HCWs met the inclusion criteria. The estimated overall seroprevalence of SARS-CoV-2 antibodies among HCWs was 8.7% (95% confidence interval 6.7-10.9%). Seroprevalence was higher in studies conducted in North America (12.7%) compared with those conducted in Europe (8.5%), Africa (8.2) and Asia (4%). Meta-regression showed that increased sensitivity of antibody tests was associated with increased seroprevalence. The following factors were associated with seropositivity: male gender; Black, Asian and Hispanic HCWs; work in a coronavirus disease 2019 (COVID-19) unit; patient-related work; front-line HCWs; healthcare assistants; shortage of personal protective equipment; selfreported belief of previous SARS-CoV-2 infection; previous positive polymerase chain reaction test; and household contact with suspected or confirmed cases of COVID-19. Conclusion: The seroprevalence of SARS-CoV-2 antibodies among HCWs is high. Excellent adherence to infection prevention and control measures; sufficient and adequate personal protective equipment; and early recognition, identification and isolation of HCWs infected with SARS-CoV-2 are imperative to decrease the risk of SARS-CoV-2 infection.