Abstract
The rapid detection of infections caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is necessary in the ongoing pandemic. Antigen-specific point-of-care tests (POCT) may be useful for this purpose. Here, such a POCT (SARS-CoV-2 NADAL® COVID-19 Ag) was compared to a laboratory-developed triplex real-time polymerase chain reaction (RT-PCR) designed for the detection of viral nucleoprotein gene and two control targets. This RT-PCR served as a reference to investigate POCT sensitivity by re-testing upper respiratory tract (URT) samples (n = 124) exhibiting different SARS-CoV-2 loads in terms of RT-PCR threshold cycle (Ct) values. The optical intensities of the antigen bands were compared to the Ct values of the RT-PCR. The infectivity of various virus loads was estimated by inoculating Vero cells with URT samples (n = 64, Ct 17-34). POCT sensitivity varied from 100% (Ct < 25) to 73.1% (Ct ≤ 30); higher SARS-CoV-2 loads correlated with higher band intensities. All samples with a Ct > 30 were negative; among SARS-CoV-2 free samples (n = 10) no false-positives were detected. A head-to-head comparison with another POCT (Abbott, Panbio™ COVID-19 Ag Rapid Test) yielded similar results. Isolation of SARS-CoV-2 in cell-culture was successful up to a Ct value of 29. The POCT reliably detects high SARS-CoV-2 loads and rapidly identifies infectious individuals.
Highlights
At the end of 2019, local health authorities reported unusual cases of pneumonia inWuhan, a large city in the Hubei Province, China [1]
A modified protocol for the MagMAX Viral/Pathogen kit (Thermo Fisher Scientific) which uses a reduced sample input and only two washing steps was applied. This protocol was recently published by the manufacturer as an application note to enable increased diagnostic throughput
The suitability of the laboratory-developed E- and N-gene triplex real-time polymerase chain reaction (RT-PCR) for SARSCoV-2 diagnostics was investigated by testing of defined EQA samples
Summary
At the end of 2019, local health authorities reported unusual cases of pneumonia inWuhan, a large city in the Hubei Province, China [1]. A novel betacoronavirus has been identified as the causative agent of the disease This virus emerged globally and is designated as severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) [1,2,3]. A few days after the first report of this novel airway infection, Corman et al published three one-step reverse transcription real-time polymerase chain reaction (RT-PCR) protocols for SARS-CoV-2 detection. These target parts of the ribonucleic acid (RNA)-dependent RNA polymerase gene, the envelope (E) protein gene, or of the nucleocapsid (N) protein gene [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
