Comparison of five SARS-CoV-2 rapid antigen detection tests in a hospital setting and performance of one antigen assay in routine practice: a useful tool to guide isolation precautions?

Abstract

Background In a hospital setting, there is a need for rapid detection of SARS-CoV-2 to guide isolation measures and targeted admission. Aim First, we evaluated the diagnostic performance of five SARS-CoV-2 rapid nucleocapsid protein antigen detection (RAD) assays (Biosynex, Biotical, Orient Gene, Panbio, SD Biosensor). Secondly, we described the performance and impact of the implementation of the SD Biosensor assay at our emergency department. Methods Sensitivity and specificity of the five RAD assays were analyzed on 100 respiratory samples: 60 real-time reverse-transcriptase-polymerase chain reaction (rRT-PCR) confirmed SARS-CoV-2 positive samples, 24 SARS-CoV-2 RNA negative samples and 16 samples positive for other respiratory pathogens. We adapted the manufacturer’s protocol, to validate the antigen tests on transport media used for rRT-PCR in our routine practice. The SD Biosensor RAD assay was implemented as screening method for rapid diagnosis and targeted admission. Findings Sensitivity of the included RAD assays ranged from 88.9% to 100% for samples with Ct <26, specificity from 46.2% to 100%. During the implementation period, 4195 RAD tests were performed. Due to the rapid RAD result, 157 patients were transferred directly to the COVID-19 cohort instead of the regular ward (n=47) or the temporary COVID-19 ward (n=110). Conclusion The SD Biosensor, Biotical and Panbio SARS-CoV-2 antigen tests had an acceptable overall performance and seem to be able to detect most of the contagious patients. In the context of high prevalence of SARS-CoV-2, RAD tests can be used as a rapid screening tool, to guide infection prevention measures and aid targeted admission.

Management of COVID-19 on board the mixed cargo ship Aranui 5

“…The Biosynex ® rapid antigenic diagnostic tests turned out to be effective. Their sensitivity between 90% and 100% and specificity between 70% and 99% have been shown to be similar to RT-PCR tests [9][10][11]. False negatives were rare.…”

Current diagnostic approaches to detect two important betacoronaviruses: Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

“…Like MERS-CoV, virus antigen test was generally reported to have lower sensitivity (<80%) in detecting the specific antigen of SARS-CoV-2, especially when this test was compared to the molecular diagnostic test like qRT-PCR [249] , [250] , [251] , [252] In terms of the test specificity, antigen test was found to be most specific (>90%) to detect SARS-CoV-2 without creating cross-reaction when other respiratory pathogens were present [249] , [250] , [251] , [252] , [253] , [254] , [255] , [256] , [257] . However, there was also some study which had reported that the antigen test results could have low specificity (as low as 46.2%) and this suggested that antigen test could be used in rapid screening of the SARS-CoV-2 infection but the use of other confirmatory tests like qRT-PCR should be conducted to confirm the viral infection [258] . As for the molecular target that is frequently used in the virus antigen test, both N and S antigens of SARS-CoV-2 are the commonly employed antigenic targets in the virus antigen test, and the LOD to detect these antigenic targets could range from 100,000 RNA copies in 1 mL to 2.86 ×107 RNA copies in a single swab [253] , [256] .…”

Evaluation of Three Covid-19 Antigen Assay Versus PCR Detection in Routine Practice

“…Specificity is consistently reported to be high. Sensitivity compared to rRT-PCR is highly variable (0-94%) and related to the viral load, with higher sensitivity reported on samples with higher viral load [2]. They would be useful for screening and diagnosis on a large scale as well as in countries with limited resources.…”