Abstract
The rapid spread of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has led the world to a pandemic. Therefore, rapid, sensitive, and reproducible diagnostic tests are essential to indicate which measures should be taken during pandemics. We retrospectively tested unextracted nasopharyngeal samples from consecutive patients with suspected SARS-CoV-2 infection (n = 334), and compared two different Ct cut-off values for interpretation of results using a modified Allplex protocol. Its performance was evaluated using the USA Centers for Disease Control and Prevention (CDC) as reference. The reduction on Ct cut-off to 35 increased the test NPA from 79.65 to 88.00 %, reducing the number of false positives, from 10.48 to 6.29 %, resulting in an almost perfect agreement between the Allplex and the CDC protocol (Cohen’s Kappa coefficient = 0.830 ± 0.032). This study demonstrates that the Seegene Allplex™ 2019-nCoV protocol skipping the viral RNA extraction step using the Ct cut-off of 35 is a rapid and efficient method to detect SARS-CoV-2 in nasopharyngeal samples.
Keywords: COVID-19; Coronavirus; Ct cut-off; Molecular diagnostics; Real time PCR.
【저자키워드】 COVID-19, coronavirus, molecular diagnostics, real time PCR, Ct cut-off, 【초록키워드】 severe acute respiratory syndrome coronavirus 2, SARS-CoV-2, coronavirus, pandemic, protocol, SARS-COV-2 infection, diagnostic test, 2019-nCoV, prevention, severe acute respiratory syndrome Coronavirus, coronavirus 2, molecular diagnostics, Spread, Viral, CDC, diagnostic tests, disease control, Interpretation, Control, Pandemics, respiratory, USA, real time PCR, False positives, reduction, acute respiratory syndrome coronavirus, consecutive patients, Nasopharyngeal samples, measure, center, coefficient, cut-off value, cut-off, Kappa coefficient, viral RNA extraction, nasopharyngeal sample, resulting, tested, detect, evaluated, reducing, consecutive patient, 【제목키워드】 SARS-CoV-2, protocol, 2019-nCoV, RT-qPCR, performance, nasopharyngeal sample,