Comprehensive infection control measures prevent hospital-acquired severe acute respiratory syndrome coronavirus 2 infection: A single-center prospective cohort study and seroprevalence survey

BACKGROUND: Coronavirus disease (COVID-19) is associated with a high mortality rate in older adults; therefore, it is important for medical institutions to take measures to prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. This study aimed to assess the risk of SARS-CoV-2 infection among healthcare workers (HCWs) and the effectiveness of infection control measures. METHODS: This study had a cross-sectional component and a prospective cohort component. The cross-sectional component comprised an anti-SARS-CoV-2 antibody survey among HCWs at a medical center in Saitama City, Japan. In the prospective cohort component, HCWs at the same medical center were tested for anti-SARS-CoV-2 antibodies monthly over a 3-month period (May to July 2020) to assess the effectiveness of infection prevention measures, including personal protective equipment use. All participants in the cohort study also participated in the antibody survey. The primary outcome was anti-SARS-CoV-2 antibody (measured using Elecsys(®) Anti-SARS-CoV-2) positivity based on whether participants were engaged in COVID-19-related medical care. Other risk factors considered included occupational category, age, and sex. RESULTS: In total, 607 HCWs participated in the antibody survey and 116 doctors and nurses participated in the cohort study. Only one of the 607 participants in the survey tested positive for anti-SARS-CoV-2 antibodies. All participants in the cohort study were anti-SARS-CoV-2 antibody negative at baseline and remained antibody negative. Engaging in the care of COVID-19 patients did not increase the risk of antibody positivity. During the study period, a total of 30 COVID-19 in-patients were treated in the hospital. CONCLUSIONS: The infection control measures in the hospital protected HCWs from nosocomially acquired SARS-CoV-2 infection; thus, HCWs should engage in COVID-19-related medical care with confidence provided that they adhere to infectious disease precautions.