Evaluation of detection of severe acute respiratory syndrome coronavirus-2 by chip-based real-time polymerase chain reaction test (truenat™ beta CoV) in multi-sample pools

Abstract

Introduction: Systematic testing for Severe Acute Respiratory Syndrome CoronaVirus-2 (SARS-CoV-2) using molecular diagnostic tools to identify individuals with coronavirus disease 2019 (COVID-19) infection, and tracing their primary and secondary contacts is important to curb its spread. With resource limitations on testing individual samples, testing of pooled samples provides alternative approach to increase testing capacity. Present aimed at assessing the detection of SARS-CoV-2 RNA in pooled samples using chip-based real-time polymerase chain reaction Test (Truenat™ Beta CoV). Materials and Methods: Pooled sample size of five was used from laboratory confirmed COVID-19 positive and negative samples. SARS-CoV-2 positive nasopharyngeal specimens of known samples from high, medium, low, and very low viral load were mixed with SARS-CoV-2 negative nasopharyngeal specimens of known samples in 1:4 ratio, followed by analysis using Truenat. Furthermore, each sample in that pool was tested individually. Pooled sample testing was also done on the samples of unknown status. Results: The results of the present study showed cycle threshold (Ct) values of pooled sample with SARS-CoV-2 positive RNA of high, medium, low, and very low viral load were 16.8, 24.22, 28.2, and 33.43, compared to Ct values of individual samples of 16.43, 22.0, 28.00, and 33.00, respectively. Conclusion: These results suggest that the Ct values of pooled samples were in agreement with Ct values of individual samples indicating the validity of pooled sample testing for screening SARS-CoV-2 using Truenat. The following core competencies are addressed in this article: Medical knowledge, Patient care and procedural skills systems-based practice, Practice-based learning and improvement.