The sensitivity and specificity of COVID-19 rapid anti-gene test in comparison to RT-PCR test as a gold standard test.

Abstract

Coronavirus disease 2019 (COVID-19) is a modern infectious disease, first identified in December 2019 in Wuhan, China. The etiology is via severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in a pandemic manner. The study aimed to compare between RT-PCR and rapid anti-gene tests for COVID-19 with regard to sensitivity and specificity. This is a cohort hospital-based study done during the period of July to September 2020. Both rapid anti-gene test kit (SARS-CoV-2) and RT-qPCR were used for the detection of COVID-19 in suspected cases. A total of 148 cases were tested using both the RT-qPCR and rapid test. Twenty-nine (19.6%) of these cases had positive results for RT-qPCR and 119 (80.4%) were negative, whereas 52 (35.1%) patients were positive to rapid anti-gene test and 96 (64.9%) of them negative. The sensitivity of the rapid test was 37.9%, the specificity was 65.5% and the accuracy was 64.44%. Rapid IgG test was positive in 47 (31.8) of cases. Although, rapid IgM test was positive in 18 (12.2%). The rapid IgG test was more sensitive than rapid IgM (Sensitivity 34.48% vs. 3.45%), but it was less specific than rapid IgM test (Specificity 68.91% vs. 85.71%). We cannot consider rapid anti-gene test alone as a diagnostic method for COVID-19. We should also conduct RT-PCR test and other investigations like imaging CT scan of chest to confirm the diagnosis. The rapid IgG test is more sensitive than rapid IgM, but it was less specific.