Journal Article

Evaluation of a novel, rapid antigen detection test for the diagnosis of SARS-CoV-2

Korsatko, Stefan, Szell, Marton, Koeller, Clara, Thell, Rainer, Toedling, Franz, Blaschke, Amelie, Laky, Brenda, Weinhappel, Wolfgang, Kallab, Verena, Kreuzer, Philipp, Heschl, Martina, Haugk, Moritz, Klicpera, Anna, Spiel, Alexander, Mueckstein, Wolfgang, Krause, Robert, Heschl, Lukas, Kreil, Anna, Sebesta, Christian, Winkler, Stefan, Herzog, Theresa

2021

Overview

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19) is currently finally determined in laboratory settings by real-time reverse-transcription polymerase-chain-reaction (rt-PCR). However, simple testing with immediately available results are crucial to gain control over COVID-19. The aim was to evaluate such a point-of-care antigen rapid test (AG-rt) device in its performance compared to laboratory-based rt-PCR testing in COVID-19 suspected, symptomatic patients. For this prospective study, two specimens each of 541 symptomatic female (54.7%) and male (45.3%) patients aged between 18 and 95 years tested at five emergency departments (ED, n = 296) and four primary healthcare centres (PHC, n = 245), were compared, using AG-rt (positive/negative/invalid) and rt-PCR (positive/negative and cycle threshold, Ct) to diagnose SARS-CoV-2. Diagnostic accuracy, sensitivity, specificity, positive predictive values (PPV), negative predictive value (NPV), and likelihood ratios (LR+/-) of the AG-rt were assessed. Differences between ED and PHC were detected regarding gender, age, symptoms, disease prevalence, and diagnostic performance. Overall, 174 (32.2%) were tested positive on AG-rt and 213 (39.4%) on rt-PCR. AG correctly classified 91.7% of all rt-PCR positive cases with a sensitivity of 80.3%, specificity of 99.1%, PPV of 98.3, NPV of 88.6%, LR(+) of 87.8, and LR(-) of 0.20. The highest sensitivities and specificities of AG-rt were detected in PHC (sensitivity: 84.4%, specificity: 100.0%), when using Ct of 30 as cut-off (sensitivity: 92.5%, specificity: 97.8%), and when symptom onset was within the first three days (sensitivity: 82.9%, specificity: 99.6%). The highest sensitivity was detected with a high viral load. Our findings suggest that AG-rt are comparable to rt-PCR to diagnose SARS-CoV-2 in COVID-19 suspected symptomatic patients presenting both at emergency departments and primary health care centres.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Antigens / Biology and Life Sciences / Coronaviruses / COVID-19 / Diagnostic systems / Emergency medical care / Emergency medical services / Health aspects / Health care / Identification and classification / Infections / Internal medicine / Laboratories / Likelihood ratio / Medical diagnosis / Medicine / Medicine and Health Sciences / Patients / Polymerase chain reaction / Primary care / Research and Analysis Methods / Respiratory diseases / Sensitivity / Serology / Severe acute respiratory syndrome / Severe acute respiratory syndrome coronavirus 2 / Signs and symptoms / Software / Viral diseases