Clinical evaluation of rapid point of care antigen tests for diagnosis of SARS-CoV-2 infection

Abstract Purpose: The RT-qPCR in respiratory specimens is the gold standard for diagnosing acute COVID-19 infections. However, this test takes considerable time before test results become available, thereby delaying diagnosed COVID-19 patients to be treated and isolated immediately. Rapid antigen tests could overcome this problem and therefore a large number of COVID-19 rapid antigen tests have been developed. Methods: In this study clinical performances of five rapid antigen tests were compared to RT-qPCR in upper respiratory specimens from 80 patients. In addition, the rapid antigen test with the best test characteristics (Romed) was evaluated in a large prospective collection of randomly selected upper respiratory specimens from 900 different COVID-19 suspected patients (300 emergency room patients, 300 nursing home patients and 300 health care workers) in the period from October 24 to November 15, 2020. Results: Overall specificity was almost 100% and sensitivity ranged from 55.0% to 80.0%. The clinical specificity of the Romed test was 99.8% (95% CI 98.9-100). Overall clinical sensitivity in the study population was 73.3% (95% CI 67.9-78.2), whereas sensitivity in the different groups varied from 65.3% to 86.7%. Sensitivity was highest in patients with short-term symptoms. In a population with a COVID-19 prevalence of 1% the negative predictive value in all patients was 99.7%. Conclusion: There is a large variability in diagnostic performance between rapid antigen tests. The Romed rapid antigen test showed a good clinical performance in patients with high viral loads, which makes this antigen test suitable for rapid identification of COVID-19 infected patients.