Evaluation of the Immunochromatography Assay's Diagnostic Performance for Quickly Detecting the Presence of COVID-19 Antigen in Patients with Positive PCR Results

Severe acute respiratory syndrome coronavirus 2 (SAR-CoV-2) is the novel infectious disease agent that causes COVID-19. The laboratory confirmation of COVID-19 is based on nucleic acid-based virus genome sequencing and real-time PCR and serological methods, rapid antigenic testing. The aim of the study was to evaluate the diagnostic sensitivity of the immunochromatography method by comparing it with PCR in covid-19 diagnosis. The study involved 116 samples, 90 samples included covid-19 patients and 26 samples included healthy, as a control group. Two nasopharyngeal swabs (NP) were taken, one for an antigenic test cassette and the other swab for re-confirmation of the infection by a real-time RT-PCR. The result of this study showed that there was a significant difference (P value = 0.0001) between RT PCR and rapid Ag tests in patients and healthy groups. The low sensitivity recorded for rapid antigen detection kits was 69% and 70%, respectively, compared with the 100% sensitivity of PCR. This study demonstrated an elevated positive rate of rapid Ag positive during the period (8–14 days) of symptoms onset. This study concluded that the rapid antigen test is a helpful tool for detecting the presence of COVID-19 infection, but it may not be the best alternative due to its low sensitivity.