Comparative study between gold standard real-time RT-PCR assay and rapid antigen test for detection of COVID-19 in Sylhet CMH

Background: The notorious pandemic coronavirus disease 2019 (COVID-19) has been spread all over the world. Its third pandemic wave has been completed and now a fourth wave is running over many countries. Almost 60 million people have been infected and more than 5.7 million people have died. Till now almost 1.2 million people have been infected and about 30000 people have died in Bangladesh from Covid-19. It has not only taken away human lives but also has put a tremendous impact on our society and economy. So early detection of this virus and isolating the patients have a significant role to control the disease. Henceforth there is an urgent need for simple, accurate and rapid identifications of C0VID -19. Rapid antigen tests can provide timely results, which is of particular importance in a primary setting. So, Performance of the Rapid antigen detection test (RAT) should be evaluated and compared with gold standard real-time reverse transcription-polymerase chain reaction (RT-PCR) test for diagnosis of COVID-19. Methods: Specimens were collected from both naso and oropharyngeal region from 1000 patients who reported to the flu centre in CMH Sylhet with the complaints of fever, cough & headache for detection of COVID virus-2 RNA by rapid antigen (RAT) and RT-PCR test. We used real time RT-PCR kit (Sansure, Biotech china, gene RdRP & N) and COVID-19 Ag Kit (Wondfo, Republic of China) for detection of COVID-19 RNA. Results: Out of 1000 samples 158 were positive and 842 were negative by real-time RT-PCR assay where 154 samples were positive, and 846 cases were negative by rapid antigen test for severe acute respiratory syndrome (SARS) CoV-2. The duration from the onset of symptoms to laboratory test in all suspected cases ranged from 0 to 02 days (with a median of 01 days). The rapid SARS-CoV-2 antigen detection tests sensitivity and specificity were 97.29% (95% CI, 90.06–99.89%) and 97.94% (95% CI, 97.26–98.57%), respectively. Seven samples were found negative in RAT but were found positive in RT-PCR, other three samples were found positive in RAT while they were found negative in RT-PCR. Conclusions: It is observed that most rapid antigen tests for COVID-19 are significantly comparable with RT-PCR tests and had enough sensitivity and specificity for 158 individuals, infected with severe acute respiratory syndrome-CoV-2.