Can Rapid Antigen Tests Lessen the Burden on Testing Laboratories? An Evaluation of the Testing Methods during the COVID-19 Pandemic

Introduction: Timely diagnosis and isolation of cases is of paramount importance to contain the spread of a pandemic. The Coronavirus Disease-2019 (COVID-19) has emerged as a major health problem that needs concerted efforts for mitigation and control. Real-time Reverse Transcription Polymerase Chain Reaction (RT-PCR), the gold-standard diagnostic modality, has high cost and can be performed in special laboratories. Rapid Antigen Tests (RAT) has been developed to serve as an alternative and is recommended to use at point-of-care testing. Aim: To compare the case detection rate of RAT and RT-PCR and the possible role they may play in the pandemic mitigation efforts. Materials and Methods: In this retrospective study, all the samples collected during a nine-months period were analysed. Depending upon the criteria, either a RAT or RT- PCR was done on the samples. Data was analysed using descriptive statistics (frequencies, mean, standard deviation, and percentages). Results: A total of 8,29,745 samples were tested during the study period among which number of positive samples was 19,414 giving an overall positivity rate of 2.34% (0.20% to 12.58%). RAT positivity was 1.58% while RT-PCR gave a positivity of 4.26. Total number of positive cases identified by RAT and RT-PCR were 9,382 and 10,032, respectively. Conclusions: RAT is a low-cost alternative to the expensive RT-PCR with the added advantage of giving accurate and timely results. This can be a game changer especially in low-resource settings, which have witnessed a increase in the spread of COVID-19 during the latter part of the pandemic.