Evaluation of rapid antigen test for detection of SARS-CoV-2 virus

Abstract

Background: The rapid diagnosis of Coronavirus Disease 2019 (COVID-19) patients is essential to reduce the disease spread. Rapid antigen detection (RAD) tests are available, however, there is scanty data on the performance of RAD tests.

Objective: To evaluate the performance of the commercially available BIOCREDIT COVID-19 Ag test and compare it with RT-PCR for detecting Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus. Analytical sensitivity for the detection of SARS-CoV-2 virus was determined for the RAD test using viral culture and RT-PCR as reference methods. The RAD test was further evaluated using respiratory samples collected from confirmed COVID-19 patients. The results were compared with RT-PCR test.

Results: The detection limits between RAD test, viral culture and RT-PCR varied hugely. RAD was 10³ fold less sensitive than viral culture while RAD was 10⁵ fold less sensitive than RT-PCR. The RAD test detected between 11.1 % and 45.7 % of RT-PCR-positive samples from COVID-19 patients.

Conclusions: This study demonstrated that the RAD test serves only as adjunct to RT-PCR test because of potential for false-negative results.

Keywords: 2019 novel coronavirus; COVID-19; RT-PCR; Rapid antigen detection; SARS-CoV-2; Viral culture.

Fig. 1

The results of the 160 respiratory samples tested for rapid antigen detection test and the corresponding Ct values of SARS-CoV-2 virus–specific RT-PCR.