Evaluation of an Antigen Detection Rapid Diagnostic Test for Detection of SARS-CoV-2 in Clinical Samples

Antigen detection rapid diagnostic tests have been developed for first-line large-scale screening given their rapidity, simplicity, and accuracy. This study evaluates the performance of an antigen test (BLOK BioScience, London, UK) detecting SARS-CoV-2 nucleocapsid protein. Serially diluted isolate 110 NPS from COVID-19 patients were tested to determine test’s sensitivity, other viral isolates 20 non-infected individuals were, specificity, also tested. Ten clinical samples with variants, including alpha, beta, gamma, delta, eta collected evaluate potential application in emerging variants. Overall sensitivity was 92%, stratifying into loads yielded 100% Ct < 25 but 11.11% ≥ 30 samples. The analytical log10 TCID50/mL 2.0 identified SARS-CoV-2. Ninety-seven percent specificity only SARS-CoV cross-reactivity lead Youden index 0.89. has a high load samples, possibly reduced low suggests its optimized usage as complementary testing method tests, RT-PCR or point-of-care screening, particularly pandemic areas airport border infection control.