Lack of sensitivity of an IVD/CE-labelled kit targeting the S gene for detection of SARS-CoV-2.

New molecular tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are being rapidly launched in response to the coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to evaluate the analytical and clinical performance of the VIASURE SARS-CoV-2 S gene RT-PCR Kit on the BD Max™ system and to compare results with those obtained with the cobas® SARS-CoV-2 test on the cobas® 6800 system. For testing the analytical performance, reference material was used. Clinical samples (n = 101) obtained from individuals with symptoms compatible with COVID-19 were studied. Oropharyngeal and nasopharyngeal swabs were collected by using either ESwab™ or UTM™ collection systems. When the analytical performance was evaluated, the sample containing the lowest SARS-CoV-2 concentration tested negative with the VIASURE test whereas results obtained with the cobas® test were found to be concordant with the results expected. Six out of the 101 clinical samples (5.9%) showed an inhibition with the VIASURE test. When analysing the remaining 95 clinical samples, 27 were found to be negative with both assays. Of 68 samples that were positive with the cobas® test, the VIASURE test missed 21 (30.9 %) samples. All of those 21 samples had shown Ct values ≥ 31 with the cobas® 6800 system. None of the samples tested positive with the VIASURE test and negative with the cobas® test. The VIASURE test was impaired by a lack of sensitivity and a relatively high number of invalid results. When using the VIASURE test for routine testing, a significant number of COVID-19-positive samples would have been missed.

Matzkies LM ，Leitner E ，Stelzl E ，Assig K ，Bozic M ，Siebenhofer D ，Mustafa ME ，Steinmetz I ，Kessler HH ... -  《-》

Evaluation of performance of two SARS-CoV-2 Rapid IgM-IgG combined antibody tests on capillary whole blood samples from the fingertip.

Prazuck T ，Colin M ，Giachè S ，Gubavu C ，Seve A ，Rzepecki V ，Chevereau-Choquet M ，Kiani C ，Rodot V ，Lionnet E ，Courtellemont L ，Guinard J ，Pialoux G ，Hocqueloux L ... -  《PLoS One》

Performance of Abbott ID Now COVID-19 Rapid Nucleic Acid Amplification Test Using Nasopharyngeal Swabs Transported in Viral Transport Media and Dry Nasal Swabs in a New York City Academic Institution.

The recent emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has posed formidable challenges for clinical laboratories seeking reliable laboratory diagnostic confirmation. The swift advance of the crisis in the United States has led to Emergency Use Authorization (EUA) facilitating the availability of molecular diagnostic assays without the more rigorous examination to which tests are normally subjected prior to FDA approval. Our laboratory currently uses two real-time reverse transcription-PCR (RT-PCR) platforms, the Roche Cobas SARS-CoV2 and the Cepheid Xpert Xpress SARS-CoV-2. The two platforms demonstrate comparable performances; however, the run times for each assay are 3.5 h and 45 min, respectively. In search for a platform with a shorter turnaround time, we sought to evaluate the recently released Abbott ID Now COVID-19 assay, which is capable of producing positive results in as little as 5 min. We present here the results of comparisons between Abbott ID Now COVID-19 and Cepheid Xpert Xpress SARS-CoV-2 using nasopharyngeal swabs transported in viral transport media and comparisons between Abbott ID Now COVID-19 and Cepheid Xpert Xpress SARS-CoV-2 using nasopharyngeal swabs transported in viral transport media for Cepheid and dry nasal swabs for Abbott ID Now. Regardless of method of collection and sample type, Abbott ID Now COVID-19 had negative results in a third of the samples that tested positive by Cepheid Xpert Xpress when using nasopharyngeal swabs in viral transport media and 45% when using dry nasal swabs.

Basu A ，Zinger T ，Inglima K ，Woo KM ，Atie O ，Yurasits L ，See B ，Aguero-Rosenfeld ME ... -  《-》

Automated SARS-COV-2 RNA extraction from patient nasopharyngeal samples using a modified DNA extraction kit for high throughput testing.

Al-Saud H ，Al-Romaih K ，Bakheet R ，Mahmoud L ，Al-Harbi N ，Alshareef I ，Judia SB ，Aharbi L ，Alzayed A ，Jabaan A ，Alhadrami H ，Albarrag A ，Azhar EI ，Al-Mozaini MA ... -  《-》

Distribution of SARS-CoV-2 PCR Cycle Threshold Values Provide Practical Insight Into Overall and Target-Specific Sensitivity Among Symptomatic Patients.

We examined the distribution of reverse transcription polymerase chain reaction (RT-PCR) cycle threshold (CT) values obtained from symptomatic patients being evaluated for coronavirus disease 2019 (COVID-19) to determine the proportion of specimens containing a viral load near the assay limit of detection (LoD) to gain practical insight to the risk of false-negative results. We also examined the relationship between CT value and patient age to determine any age-dependent difference in viral load or test sensitivity. We collected CT values obtained from the cobas severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) assay corresponding to 1,213 combined nasopharyngeal-oropharyngeal specimens obtained from symptomatic individuals that were reported as positive or presumptive positive for SARS-CoV-2. CT values were stratified by SARS-CoV target and patient age group. In total, 93.3% to 98.4% of specimens demonstrated CT values greater than 3× the assay LoD, at which point false-negative results would not be expected. The mean of CT values between age groups was statistically equivalent with the exception of patients in age group 80 to 89 years, which demonstrated slightly lower CTs. Based on the distribution of observed CT values, including the small proportion of specimens with values near the assay LoD, there is a low risk of false-negative RT-PCR results in combined nasopharyngeal-oropharyngeal specimens obtained from symptomatic individuals.

Buchan BW ，Hoff JS ，Gmehlin CG ，Perez A ，Faron ML ，Munoz-Price LS ，Ledeboer NA ... -  《-》