Speaker

Chatzantonaki Kalliopi

Biography :

The objective of this study was to evaluate the efficiency of combined use of commercial RT-PCR methods for the molecular detection of SarsCov-2 RNA, in the presence of currently circulating Variants of Concern (VOCs) and how these variants may dynamically interfere with an analytical RealTime PCR result (Ct). There is evidence that some VOCs may escape from exhibing adequate fluorecent signal. Additional evidence shows than certain VOCs may present S gene dropout, leading to false negative results as regards the analysis of S gene, whereas certain PCR kit may be more susceptible to S gene dropout compared to others for specific VOC. Our lab proceeded in the statistical analysis of a sufficient number of External Quality Contol samples regarding the schemes INSTAND & UK NEQAS External Quality Assurance of Coronoviruses Gemone Detection (RNA). The main result was that a given cycle cutoff (Ct) should be interpreted with care and in tandem with the current stage of the pandemic, as it may not always be directly connected with the viral load. In parallel with this study, our laboratory tried to illustrate in diagrams the preference of the laboratories, in terms of most commonly used kit manufacturer and genes targets, as derived from the participations in two well-known External Quality Assurance Shemes reflecting current laboratory practices and trends. With a strong commitment to Quality, our laboratory’s current Quality Assurance Practice follows the combined detection of five SarsCov-2 related genes (S/RdRp, E, N, ORF1a/b) within the same limit of detection, which in turn is proved to lead to enhanced sensitivity and providing a safe protocol for Covid-19 diagnosis and quantification.