Publication
Assessing the effectiveness of sample and RNA extract pool testing for the detection of SARS-CoV-2 RNA by real time RT-PCR
Publisher:
Sri Lanka Journals Online (JOL)
Date:
25-08-2023
DOI:
10.4038/SLJID.V13I2.8574
Abstract: Introduction: Pooled testing is a cost-effective approach to increasing testing capacity during pandemics. This study analysed the effectiveness of pooling of s les and RNA extracts for the detection of SARS-CoV-2 by real time RT-PCR.Methods: Twenty SARS-CoV-2 positive s les with Ct value of 25–35 and 60 known negative s les based on initial PCR results were used for this study. The s les were used to prepare 2-, 4- and 8-fold pooled s les prior to extraction. The RNA extracts of a further 10 PCR positive s les were pooled to prepare 2-, 4- and 8-fold RNA extract pools. The Ct values of neat s les and pooled s les were compared using the paired t-test with a 95% confidence interval. The same was done for the neat RNA extracts and the extract pools.Results: The detection capacity was considerably lower when the pool size was increased from 2- to 8-fold in s le pooling, whereas pools of RNA extracts showed 100% detection from 2- to 8-fold dilution. The increase in Ct value of 2-, 4- and 8-fold s le dilutions were 1.69 ± 0.78, 3.84 ± 1.47 and 8.98 ± 2.25, respectively (P 0.0001). However, there was a small rise in the Ct value of 2-, 4- and 8-fold extract pools (1.01 ± 0.38, 2.18 ± 0.82 and 3.05 ± 0.77, respectively).Conclusions: Large scale screening of asymptomatic in iduals for SARS-CoV-2 can be maximised with optimal use of resources by 2- or 4-fold pooling of s les or 4- or 8-fold pooling of RNA extracts without significantly compromising the detection capacity.