Comparison of Positivity Rates of COVID-19 Rapid Antigen Tests (RAT) and GeneXpert During COVID-19 Pandemic in a Tertiary Care Hospital, Mumbai, Maharashtra

The advent of the coronavirus disease 2019 (COVID-19) in India caused a new range of challenges in diagnosing the virus & containing its community spread. Various point-of-care tests have been introduced for rapid diagnosis. Although rapid antigen tests (RAT) are the most commonly used, the false-negative rates are high. The purpose of this study was to compare the positivity rate of a molecular diagnostic test such as GeneXpert in RAT negative cases of COVID-19 during COVID pandemic. A retrospective observational analysis conducted on a total of 13633 symptomatic patients’ samples were tested for RAT & GeneXpert of which 1508 were positive (11.06%). Out of 20526 symptomatic patients tested for GeneXpert, 3811 were positive (18.56%) and out of 12125 RAT negatives, 214 patients tested GeneXpert positive (1.8%). The main conclusions of this study were that negative rapid antigen tests should always be confirmed with a molecular diagnostic test such as GeneXpert or RT-PCR for the diagnosis of COVID-19 in symptomatic patients. Proper methods of sample collection must be ensured as improper methods might lead to increase in the number of false-negative results on point-of-care &; screening tests.