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1.
Arch Pathol Lab Med ; 144(11): 1303-1310, 2020 11 01.
Article in English | MEDLINE | ID: covidwho-937676

ABSTRACT

CONTEXT.­: We implemented multiple nucleic acid amplification test platforms because of the limited availability of test kits for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the early stages of the pandemic. Interpretation of results generated by different platforms and prioritization for testing algorithms required cross-comparison. OBJECTIVE.­: To compare the analytical sensitivity of 3 commercial SARS-CoV-2 molecular assays, selected samples were studied in parallel with Cobas SARS-CoV-2 test, NxTAG CoV Extended Panel, and ID NOW COVID-19 assays. DESIGN.­: A total of 8043 SARS-CoV-2 tests performed from March 22 to April 19, 2020, were included in this study. For all 1794 positive specimens detected by the cobas SARS-CoV-2 assay, the cycle threshold (Ct) values were manually tracked and plotted to demonstrate the distribution of sample viral levels. Additionally, 50 and 63 low-positive specimens (Ct values >32) as well as 50 and 61 consecutive positive specimens by the cobas assay were tested with NxTAG and ID NOW, respectively, to estimate their relative sensitivities. RESULTS.­: The Ct values of cobas SARS-CoV-2-positive samples were evenly distributed throughout ranges of 13.32 to 39.50 (mean, 25.06) and 13.60 to 42.49 (mean, 26.45) for ORF1 and E gene targets, respectively. NxTAG reliably detected only specimens with E gene Ct values lower than 33, and is estimated to detect 89.4% of positive specimens detected by cobas assay. ID NOW had performance variation independent of Ct value and is estimated to detect 83.5% of cobas positives. CONCLUSIONS.­: Clinical specimens exhibit a wide range of viral burden, with a significant portion at low levels. Analytical sensitivity of testing platforms is critical for reliable detection of SARS-CoV-2 and uniform care to patients.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/diagnosis , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , Pneumonia, Viral/diagnosis , SARS Virus/genetics , Severe Acute Respiratory Syndrome/diagnosis , Adult , Betacoronavirus/isolation & purification , Betacoronavirus/physiology , COVID-19 , Clinical Laboratory Techniques/methods , Coronavirus Infections/virology , Diagnosis, Differential , Early Diagnosis , Female , Humans , Male , Middle Aged , Nasopharynx/pathology , Nasopharynx/virology , Pandemics , Pneumonia, Viral/virology , SARS Virus/isolation & purification , SARS Virus/physiology , SARS-CoV-2 , Sensitivity and Specificity , Severe Acute Respiratory Syndrome/virology , Specimen Handling/instrumentation , Specimen Handling/methods
2.
J Neurol Neurosurg Psychiatry ; 91(8): 846-848, 2020 08.
Article in English | MEDLINE | ID: covidwho-154812

ABSTRACT

BACKGROUND: Emergence of the novel corona virus (severe acute respiratory syndrome (SARS)-CoV-2) in December 2019 has led to the COVID-19 pandemic. The extent of COVID-19 involvement in the central nervous system is not well established, and the presence or the absence of SARS-CoV-2 particles in the cerebrospinal fluid (CSF) is a topic of debate. CASE DESCRIPTION: We present two patients with COVID-19 and concurrent neurological symptoms. Our first patient is a 31-year-old man who had flu-like symptoms due to COVID-19 and later developed an acute-onset severe headache and loss of consciousness and was diagnosed with a Hunt and Hess grade 3 subarachnoid haemorrhage from a ruptured aneurysm. Our second patient is a 62-year-old woman who had an ischaemic stroke with massive haemorrhagic conversion requiring a decompressive hemicraniectomy. Both patients' CSF was repeatedly negative on real-time PCR analysis despite concurrent neurological disease. CONCLUSION: Our report shows that patients' CSF may be devoid of viral particles even when they test positive for COVID-19 on a nasal swab. Whether SARS-CoV-2 is present in CSF may depend on the systemic disease severity and the degree of the virus' nervous tissue tropism and should be examined in future studies.


Subject(s)
Betacoronavirus/isolation & purification , Coronavirus Infections/cerebrospinal fluid , Coronavirus Infections/complications , Pneumonia, Viral/cerebrospinal fluid , Pneumonia, Viral/complications , Stroke/complications , Stroke/virology , Adult , COVID-19 , Female , Humans , Male , Middle Aged , Pandemics , SARS-CoV-2 , Stroke/cerebrospinal fluid
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