Evaluation of novel antigen-based rapid detection test for the diagnosis of SARS-CoV-2 in respiratory samples

Int J Infect Dis. 2020 Jun 1;S1201-9712(20)30405-7. doi: 10.1016/j.ijid.2020.05.098. Online ahead of print.

Abstract

Objectives: In the context of the Covid-19 pandemic, the development and validation of rapid and easy-to-perform diagnostic methods are of high priority. We evaluated a novel rapid antigen detection test (RDT) for SARS-CoV-2 in respiratory samples.

Methods: The fluorescence immunochromatographic SARS-CoV-2 antigen test (Bioeasy Biotechnology Co., Shenzhen, China) was evaluated using universal transport medium with nasopharyngeal (NP) and oropharyngeal (OP) swabs from suspected Covid-19 cases. Diagnostic accuracy was determined in comparison to SARS-CoV-2 real time (RT)-PCR.

Results: A total of 127 samples were included; 82 were RT-PCR positive. Median patients' age was 38 years, 53.5% were male, and 93.7% were from the first week after symptom onset. Overall sensitivity and specificity were 93.9% (CI95% 86.5-97.4) and 100% (CI95% 92.1-100), respectively, with a diagnostic accuracy of 96.1% and Kappa coefficient of 0.9. Sensitivity was significantly higher in samples with high viral loads.

Conclusions: The evaluated RDT showed a high sensitivity and specificity in samples mainly obtained during the first week of symptoms and with high viral loads, despite the use of a non-validated sample material. The assay has the potential to become an important tool for early diagnosis of SARS-CoV-2, particularly in situations with limited access to molecular methods.

Keywords: Coronavirus; Covid-19; SARS-CoV-2; antigen; diagnosis; rapid diagnostic test.