XÁC ĐỊNH GIÁ TRỊ SỬ DỤNG CỦA PHƯƠNG PHÁP GỘP DUNG DỊCH TRONG CHẨN ĐOÁN SARS-COV-2 BẰNG KỸ THUẬT RT-qPCR

Abstract

Introduction: The current guidance from the Misnistry of Health regarding pooling methods applied in SARS-CoV-2 testing endorses swab pooling and sample/media pooling. Sample/media pooling method shows comparative advantages, including the absence of re-sampling, minimal risk of cross-infection and of inconsistant testing results. Even with such benefits, sample/media pooling method requires a rigorous validation prior to extensive deployment. The study aims to evaluate (1) the impact of sample dilution on the final testing accuracy and (2) the optimal number of samples in a pool. Methods: This is an experimental study with prospective data collection. Experiements were performed using PureLink™ Viral RNA/DNA Mini Kit (Invitrogen, Hoa Kỳ), TaqPath™ COVID‑19 CE‑IVD RT‑PCR Kit (ThermoFisher, Hoa Kỳ) and SARS-CoV-2 positive nasopharyngeal swab stored in VTM. Results: The single samples with high and medium viral load (Ct <30) have the positivity concordance of 100% with 5-sample and 10-sample pools, while those with low viral load (Ct >30) have the concordance of 100% and 80% with 5-sample and 10-sample pools, respectively. Mean Ct gap of all three tested genes in 5-sample pooling is 2.05 (95% CI, 1.93 – 2.16), and in10-sample pooling is 2.87 (95% CI, 2.63 – 3.11). In the pooling simulation, the positivity concordance of both 5-sample pooling and 10-sample pooling is 100%, compared to single sample testing. Conclusion: Sample/media pooling is a method displaying high reliability in SARS-CoV-2 testing. Its wide implementation potentially generates lots of benefits in screening and diagnosis of SARS-CoV-2 infection by RT-qPCR.