Evaluation of Novel Antigen-Based Rapid Detection Test for the Diagnosis of SARS-CoV-2 in Respiratory Samples

Background: In the context of the COVID-19 pandemic, the development and validation of rapid and easy-to-perform diagnostic methods are of high priority to enable the required testing scale up in most countries. We evaluated a novel rapid antigen detection test (RDT) for SARS-CoV-2 in respiratory samples. Method: sA new fluorescence immunochromatographic SARS-CoV-2 antigen detection test (Bioeasy Biotechnology Co., Shenzhen, China) was evaluated in nasophayngeal (NP) and oropharyngeal (OP) swabs from patients with suspected COVID-19 in Santiago, Chile. Diagnostic accuracy was determined in comparison to SARS-CoV-2 real time (RT)-PCR, using the same material (universal transport medium with NP and OP swab). Findings: A total of 127 samples were included. The median patients’ age was 38 years (IQR 29·5–44), 53·5% were male, and 93·7% were in the first week after symptom onset. Among 82 RT-PCR positive specimens, 77 were correctly detected by RDT. All 45 RT-PCR negative samples were correctly identified. The overall sensitivity and specificity of the RDT 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 increased viral loads. Interpretation: The antigen-based immunofluorescence RDT showed a high sensitivity and specificity in respiratory samples obtained from patients who mainly presented during the first week of COVID-19, despite the use of a non-validated sample. The assay was easy to use and provided results in a timely manner. It has the potential to become an important tool for early diagnosis of SARS-CoV-2, particularly in situations with limited access to molecular methods. Funding Statement: This work did not receive funding. Declaration of Interests: All authors declare no competing interests. Ethics Approval Statement: The study was approved by the local Institutional Review Board (Comite Etico Cientifico, Facultad de Medicina Clinica Alemana, Universidad del Desarrollo, Santiago, Chile) and need for informed consent was waived.