Comparative Evaluation of RT-PCR Kits Available in Sri Lanka for Diagnosis of COVID-19

Abstract

Identification of gene targets by real-time reverse transcriptase PCR (rRT-PCR) is considered as the gold standard for diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Although many commercial rRT-PCR kits are currently used in Sri Lanka, analytical performance of these kits have not been investigated adequately. Therefore, the objective of the present study was to evaluate the analytical performance of rRT-PCR kits used in the laboratory of the Faculty of Medicine, University of Jaffna (five kits). Performance of the five rRT-PCR kits selected for this study was compared with the CDC 2019-Novel Coronavirus (2019-nCoV) RT-PCR Diagnostic Panel as reference standard. The sensitivity, specificity, positive predictive value, negative predictive value and Cohen’s κ coefficient of the five different commercial kits were analyzed. SARS-CoV-2 positive (62) and negative (32) respiratory samples collected respectively from symptomatic individuals and asymptomatic healthy individuals were used in this study. Comparison of the cycle threshold (Ct) values of the five commercial kits revealed heterogeneity. Among them, the TaqPathTM kit showed the highest sensitivity (98.4%) and interrater reliability (0.976). The HBRT-COVID-19 kit showed the lowest sensitivity (91.9%), specificity (93.7%) and interrater reliability (0.838). Although the five RT-PCR kits exhibited varying sensitivity, specificity and Ct values, all of them are suitable for the routine diagnosis of SARS-CoV-2 infections as all values were higher than 90%.