A retrospective cohort study of the effect of SARS-CoV-2 point of care rapid RT-PCR at the Emergency Department on targeted admission.

BACKGROUND: To prevent nosocomial transmission of SARS-CoV-2, infection prevention control (IPC) measures are implemented for patients with symptoms compatible with COVID-19 until reliable test results are available. This delays admission to the most appropriate ward based on the medical condition. SARS-CoV-2 rapid antigen detection (RAD) tests and point-of-care (POC) rapid RT-PCR (VitaPCR) were introduced at emergency department (ED) at Skåne University Hospital, Sweden in late 2020, but the consequence on patient flow and targeted admission is unknown. METHODS: Patients presenting at the emergency department of a referral hospital (N = 2940) between 13-Nov-2020 and 12-Jan-2021 were included. The study period was delimited into three periods by the introduction of RAD tests and the VitaPCR. Participant data was collected from hospital records, and outcome variables were Length-of-Stay (LoS), intrahospital transfers and targeted admission to COVID-19 ward. RESULTS: Compared to baseline (RT-PCR only), RAD tests reduced ED Length-of-Stay (LoS) for participants with positive tests. Negative VitaPCR results reduced mean hospital LoS by 1.5 (95% CI 0.3-2.7) days and admissions to COVID-19 wards from 34.5 (95% CI 28.9-40.5) to 14.7 (95% CI 11.1-19.1) per 100 admissions and reduced transfers between hospital wards in the first 5 days from 50.0 (95% CI 45.0-55.0) to 34.0 (95% CI 30.3-37.9) per 100 admissions. CONCLUSION: RAD tests enabled prompt detection of SARS-CoV-2 infection which had pronounced effects on LoS at the ED. Negative VitaPCR enabled cessation of IPC measures and a negative test was associated with increased targeted admissions, reduced intrahospital transfers and shorter LoS at the hospital.

Detection of SARS-CoV-2 by rapid antigen tests on saliva in hospitalized patients with COVID-19.

BACKGROUND: The COVID-19 pandemic presents great challenges on transmission prevention, and rapid diagnosis is essential to reduce the disease spread. Various diagnostic methods are available to identify an ongoing infection by nasopharyngeal (NPH) swab sampling. However, the procedure requires handling by health care professionals, and therefore limits the application in household and community settings. OBJECTIVES: In this study, we aimed to determine if the detection of SARS-CoV-2 can be performed alternatively on saliva specimens by rapid antigen test. STUDY DESIGN: Saliva and NPH specimens were collected from 44 patients with confirmed COVID-19. To assess the diagnostic accuracy of point-of-care SARS-CoV-2 rapid antigen test on saliva specimens, we compared the performance of four test products. RESULTS: RT-qPCR was performed and NPH and saliva sampling had similar Ct values, which associated with disease duration. All four antigen tests showed similar trend in detecting SARS-CoV-2 in saliva, but with variation in the ability to detect positive cases. The rapid antigen test with the best performance could detect up to 67% of the positive cases with Ct values lower than 25, and disease duration shorter than 10 days. CONCLUSION: Our study therefore supports saliva testing as an alternative diagnostic procedure to NPH testing, and that rapid antigen test on saliva provides a potential complement to PCR test to meet increasing screening demand.