Point-of-care lung ultrasound predicts severe disease and death due to COVID-19: a prospective cohort study. (preprint)

Objective: The clinical utility of point-of-care lung ultrasound (LUS) for disease severity triage of hospitalized patients with COVID-19 is unclear. Design: Prospective cohort study Setting: A large tertiary care center in Maryland, USA between April 2020 to September 2021. Patients: Hospitalized adults (18 years of age or greater) with positive SARS-CoV-2 RT-PCR results. Interventions: None. Measurements and Main Results: All patients were scanned using a standardized protocol including 12 lung zones and followed to determine clinical outcomes until hospital discharge and vital status at 28-days. Ultrasounds were independently reviewed for lung and pleural line artifacts and abnormalities, and the mean Lung Ultrasound Score (ranging from 0 to 3) across lung zones (mLUSS) was determined. The primary outcome was time to ICU-level care, defined as high flow oxygen, noninvasive, or mechanical ventilation, within 28-days of the initial ultrasound. Cox proportional hazards regression models adjusted for age and sex were fit for mLUSS and each ultrasound covariate. A total of 264 participants were enrolled in the study; the median age was 59 years and 114 (43.2) % of participants were female. The median mLUSS was 1 (interquartile range: 0.5 to 1.3). Following enrollment, 29 (11.0%) participants went on to require ICU-level care and 14 (5.3%) subsequently died by 28 days. Each increase in mLUSS at enrollment was associated with disease progression to ICU-level care (aHR = 3.63; 95% CI: 1.23 to 10.65) and 28-day mortality (aHR = 4.50; 95% CI: 1.52 to 13.31). Pleural line abnormalities were independently associated with disease progression to ICU-level care (aHR = 18.86; CI: 1.57 to 226.09). Conclusions: Participants with a mLUSS of 1 or more or pleural line changes on LUS had an increased likelihood of subsequent requirement of high flow oxygen or greater. LUS is a promising tool for assessing risk of COVID-19 progression at the bedside.

A Novel Amplification-free SARS-CoV-2 Point-of-care Nucleic Acid Detection System based on Hybrid Capture Fluorescence Immunoassay (preprint)

Herein we presented a novel, rapid and amplification-free SARS-CoV-2 nucleic acid detection system based on hybrid capture fluorescence immunoassay (HC-FIA) technology. The usage of the monoclonal antibody S9.6 in recognizing DNA-RNA double-stranded hybrids enabled the conversion of nucleic acid testing into immunofluorescence carrying on a simple lateral flow dipstick. The established HC-FIA also exhibited satisfactory sensitivity, specificity and great robustness. The clinical evaluation of HC-FIA kit and fluorescence reading device are further processed in three hospitals independently. The results of 734 samples from 670 subjects indicated high consistency between our HC-FIA and quantitative polymerase chain reaction based commercially available kit or clinical diagnosis according to Kappa statistics. Altogether, HC-FIA related method and commercial test kit show unparalleled advantages as time saving, amplification-free, high throughput and portable POCT molecular diagnosis, which facilitates its application as on-site Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid detection in epidemic prevention and control worldwide, especially during the outbreak.