DNA amplification tests at universal pre-admission screening with enhanced precaution strategies for asymptomatic patients with COVID-19

Abstract

To analyze the effect of hospital preadmission screening and an enhanced precaution strategy on COVID-19 transmission. We conducted a retrospective cohort study over 17 months from 11 May 2020 to 30 September 2021 at a large hospital in Tokyo. Universal DNA amplification tests were conducted during preadmission screening, and enhanced precaution strategies were implemented for all patients with a negative admission test. The primary outcome was the occurrence of symptomatic COVID-19 in patients after admission. The secondary outcomes were time-series analyses of monthly positive admission test numbers, positive rates, clinical features in positive cases, and clinically confirmed nosocomial transmission. A total of 32,081 patients were screened during preadmission (29,556 asymptomatic patients and 2525 symptomatic patients). Of the asymptomatic patients, 0.11% (n = 32) tested positive and were admitted to a COVID-19-designated ward or were not admitted. Among the five inpatients who developed symptomatic COVID-19 during hospitalization, only two cases were related to a single nosocomial transmission. Preadmission test screening was effective in identifying asymptomatic COVID-19 patients. This allowed administrators to quarantine patients or delay admittance. The combination of testing and enhanced precaution strategies for asymptomatic patients with COVID-19 might minimize nosocomial transmission.