Serology Suggests Adequate Safety Measures to Protect Healthcare Workers From COVID-19 in Shiga Prefecture, Japan

Abstract

Background: Healthcare workers (HCWs), especially frontline workers against coronavirus disease 2019 (COVID-19), are considered to be at increased risk of infection because of occupational exposure to infected patients. This study evaluated the correlation between seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies among HCWs and the implementation of personal protective equipment (PPE) & infection prevention and control (IPC). Methods: We prospectively recruited 1237 HCWs from nine public COVID-19-designated hospitals in Shiga Prefecture, central Japan, between 15–26 February 2021. All participants answered a self-administered questionnaire and provided blood samples to evaluate SARS-CoV-2 antibodies. Findings: A total of 22 cases (1·78%) were seropositive among the 1237 study participants. Half of the participants (n=500; 48·8%) had worked in red zones designated for COVID-19, where high exposure to SARS-CoV-2 was suspected in the past months. Seven (7/1025; 0·68%) HCWs were suspected to have had previous SARS-CoV-2 infections. From these, binomial logistic regression from individual questionnaires and seropositivity predicted a significant correlation with N95 mask usage under aerosol conditions and work duration in a red zone. The institutional questionnaire suggested that IPC education was correlated with reduced seropositivity at hospitals. Interpretation: Seroprevalence and questionnaire analyses among HCWs indicated that secure implementation of PPE and re-education of IPC are essential to prevent SARS-CoV-2 infection within healthcare facilities. Occupational infections from SARS-CoV-2 in healthcare settings can be prevented by adhering to adequate measures and appropriate use of PPE. With these measures securely implemented, HCWs should not be discriminated against as risky or dirty by local communities. Funding Information: Shiga Prefecture and Shiga University of Medical Science Hospital funded the administrative costs of this study.Declaration of Interests: No authors have conflicts of interest to declare.Ethics Approval Statement: This study was approved as an administrative investigation of Shiga Prefecture by the Research Review Board of Shiga University of Medical Science (No. RRB20-032). Written informed consent and self-administered questionnaires were obtained from all study participants.