Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology
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Serological SARS-CoV-2 assays are urgently needed for diagnosis, contact tracing and for epidemiological studies. So far, there is limited data on how recently commercially available, high-throughput immunoassays, using different recombinant SARS-CoV-2 antigens, perform with clinical samples. Focusing on IgG and total antibodies, we demonstrate the performance of four automated immunoassays (Abbott Architect™ i2000 (N protein-based)), Roche cobas™ e 411 analyzer (N protein-based, not differentiating between IgA, IgM or IgG antibodies), LIAISON®XL platform (S1 and S2 protein-based), VIRCLIA® automation system (S1 and N protein-based) in comparison to two ELISA assays (Euroimmun SARS-CoV-2 IgG (S1 protein-based) and Virotech SARS-CoV-2 IgG ELISA (N protein-based)) and an in-house developed plaque reduction neutralization test (PRNT). ⋯ This should be further analysed. The specificity of the examined assays was ≥ 97%. However, because of the low or unknown prevalence of SARS-CoV-2, the examined assays in this study are currently primarily eligible for epidemiological investigations, as they have limited information in individual testing.
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Comparative Study
Performance evaluation of Abbott ARCHITECT SARS-CoV-2 IgG immunoassay in comparison with indirect immunofluorescence and virus microneutralization test.
Serological tests for anti-SARS-CoV-2 antibodies are becoming of great interest to determine seroprevalence in a given population, define previous exposure and identify highly reactive human donors for the generation of convalescent serum as therapeutic. ⋯ In our study, Abbott ARCHITECT SARS-CoV-2 IgG assay showed a satisfactory performance, with a very high specificity. IgG reactivity against SARSCoV-2 N antigen was detectable in all patients by two weeks after symptoms onset. In addition, concordance between this serological response and viral neutralization suggests that a strong humoral response may be predictive of a neutralization activity, regardless of the target antigens. This finding supports the use of this automated serological assay in diagnostic algorithm and public health intervention, especially for high loads of testing.
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Severe acute respiratory coronavirus 2 (SARS-CoV-2) has spread and caused death worldwide. Preventive measures and infection control are underway, and some areas show signs of convergence. Other viruses in addition to SARS-CoV-2 cause cold-like symptoms and spread in the winter. However, the extent to which SARS-CoV-2, influenza viruses and other causative viruses have prevailed since implementing preventive measures is unclear. ⋯ Co-infection with SARS-CoV-2 and other viruses was not observed. Causative viruses remain prevalent after implementing preventive measures. SARS-CoV-2 differs from influenza viruses in its infectivity.
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With the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there is an urgent need for more rapid and simple detection technologies at the forefront of medical care worldwide. In this study, we evaluated the effectiveness of the Loopamp® 2019-SARSCoV-2 Detection Reagent Kit, which uses loop-mediated isothermal amplification (LAMP) technology. In this protocol, cDNA is synthesized from SARS-CoV-2 RNA using reverse transcriptase, followed by DNA amplification under isothermal conditions in one step. ⋯ Comparison with the results of RT-qPCR for 76 nasopharyngeal swab samples from patients with suspected COVID-19 showed a sensitivity of 100 % and a specificity of 97.6 %. In the 24 RNA specimens derived from febrile Japanese patients with or without influenza A, no amplification was observed using RT-LAMP. RT-LAMP could be a simple and easy-to-use diagnostic tool for the detection of SARS-CoV-2.