Comparability of the Sensitivity of Different real time PCR kits Used in the Detection of SARS CoV -2

ABSTRACT

Background:COVID-19 pandemic is posing a major burden on society. Measures taken to reduce its spread critically de- pend on timely and accurate identification of virus-infected individuals by the most sensitive and specific method availa- ble, i.e. real-time reverse transcriptase PCR (RT-PCR). RT PCR can detect SARS-CoV-2 as early as day one of symptom onset. There are various RT PCR kits approved by FDA & ICMR, performance of which vary widely. Here, we assessed the performance of four PCR kits with the ICMR NIV Screening & Confirmatory assay used for diagnosis of COVID -19 in Od- isha. Methods:A total of 20 samples, which included five positives, one inconclusive & 14 negative samples by NIV assay were evaluated in the four commercially available RT-PCR kits ie;Q-line Molecular (Q-line), Allplex™ 2019-nCoV Assay (Allplex), Liferiver Novel Coronavirus (COVID-19) Multiplex RT PCR (Liferiver), LabGun™ COVID-19 kit (LabGun). Results:The sensitivity of the four PCR kits varied with the high cycle threshold (Ct) value (30-35 by NIV) & the lower Ct value (<30 by NIV). Among the negative results of NIV (n=14), LabGun, Allplex kits showed 100% concordance, while Q - line & Life river were shown to have 92.8% & 50% concordance respectively. In the inconclusive results (n=1), only All- plex Assay documented a concordance of 100% with the NIV assay, while the Q -line (n=6) & Life river (n=7) showed higher number of inconclusive results. The different kits showed lesser variations with positive results (n=5), with Life river, Allplex & LabGun showing 100% concordance for positive results with NIV assay. However, Q -line was able to de- tect only 1 positive out of all positives. Conclusions:PCR kits vary in sensitivity & it is imperial to evaluate the various kits in order to deliver accurate results at optimum time in order to detect the cases to initiate adequate treatment & control measures: