Comparison of coronavirus disease 19 rapid diagnostic test with gold standard real time reverse transcription polymerase chain reaction in omicron wave of pandemic

Background: The Omicron variant of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the most mutated variant identified and contributed to the third wave of the coronavirus disease-19 (COVID-19) pandemic. Due to its high transmissibility, it has replaced the Delta variant, which was the dominant variant during the second wave of the pandemic. Aims and Objectives: This study aims to evaluate whether the highly transmissible, rapidly multiplying, and frequently transforming Omicron variant of SARS-CoV-2 affects the performance of rapid antigen tests (RAT) in the third wave of the COVID-19 pandemic. Materials and Methods: This retrospective study was conducted in a tertiary care hospital in the initial period of the third wave of the COVID-19 pandemic. Socio-demographic information was collectedfrom 480 patients whose nasopharyngeal swabs were received for both RAT and reverse transcription-polymerase chain reaction (RT-PCR) testing. Results: Male preponderance was seen in all patients’ age groups. Substantial agreement between RAT and gold standard RT-PCR was observed. When samples that tested positive by RAT were further analyzed with RT-PCR, most of them showed a cycle threshold value below 25, indicating a higher viral load. Sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio of the COVID-19 RAT were 46.03%, 99.52%, 93.54%, 92.42%, 95.87%, and 0.54%, respectively. Conclusion: The RAT shows high specificity and good agreement with RT-PCR results, making it suitable as a quick point-of-care screening tool, especially in hospitals and areas with high infection rates. TheOmicron variant did not significantly affect the performance of RAT.