Comparison of Positivity Rates of Rapid Antigen Testing and Real-Time Polymerase Chain Reaction for COVID-19 During the First and Second Waves of the Pandemic in Eastern Uttar Pradesh, India.

Background The advent of the second wave of coronavirus disease 2019 (COVID-19) in India caused a new range of challenges in diagnosing the virus. Various point-of-care tests have been introduced for rapid diagnosis. Although rapid antigen tests are the most commonly used, the false-negative rates are high. Therefore, the purpose of this study was to compare the positivity rate of real-time polymerase chain reaction (RT-PCR) testing in rapid antigen-negative cases of COVID-19 during the first and second waves of the COVID-19 pandemic. Methodology This was an observational study conducted in the Department of Microbiology, All India Institute of Medical Sciences, Gorakhpur. Results In total, 2,168 patients were tested. The percentage positivity rate of the RT-PCR tests among the antigen-negative samples was 4.34% in the first wave of the pandemic whereas it was 8.08% in the second wave. Conclusions The main conclusion of this study was that antigen tests should never be used alone for the diagnosis of COVID-19. Instead, they should be confirmed with a RT-PCR test.