Diagnostic microbiology and infectious disease
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Diagn. Microbiol. Infect. Dis. · Jan 2021
Comparative StudyComparison of 2 fully automated tests detecting antibodies against nucleocapsid N and spike S1/S2 proteins in COVID-19.
Automated assays for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in coronavirus disease 2019 (COVID-19) diagnostics have recently come available. We compared the performance of the Elecsys® Anti-SARS-CoV-2 and LIAISON® SARS-CoV-2 S1/S2 IgG tests. The seroconversion panel comprised of 120 samples from 13 hospitalized COVID-19 patients. ⋯ Based on our results, the SARS-CoV-2 antibodies can be quite reliably detected 2 weeks after NAAT positivity and 3 weeks after the symptom onset with both tests. However, since some COVID-19 patients were positive only with Elecsys®, the antibodies should be screened against N-antigen (Elecsys®) and reactive samples confirmed with S antigen (LIAISON®), but both results should be reported. In some COVID-19 patients, the serology can remain negative.
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Diagn. Microbiol. Infect. Dis. · Jan 2021
Comparative StudyAnalysis of sputum/tracheal aspirate and nasopharyngeal samples for SARS-CoV-2 detection by laboratory-developed test and Panther Fusion system.
In this study, 127 sputum/tracheal aspirate specimens were evaluated by a laboratory-developed real-time RT-PCR method and Fusion SARS-CoV-2 assay. These specimens were collected from the patients who have nasopharyngeal swab (NPS) samples being used for SARS-CoV-2 detection previously or simultaneously. The overall agreement was 96% between the lower respiratory tract (LRT) and NPS samples, suggesting that LRT specimens could be an option for patients who develop a productive cough or those receiving invasive mechanical ventilation.
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Diagn. Microbiol. Infect. Dis. · Jan 2021
Dacron swab and PBS are acceptable alternatives to flocked swab and viral transport media for SARS-CoV-2.
Nasopharyngeal flocked swabs placed in viral transport media (VTM) are the preferred collection methodology for respiratory virus testing. Due to the rapid depletion of available reagents and swabs, we have validated an alternative swab placed in phosphate-buffered saline (PBS) for use in respiratory virus testing in a SARS-CoV-2 real-time polymerase chain reaction assay and a multiplexed respiratory virus panel. ⋯ In this feasibility study, we show that NP collection is better for detection of human material than OP collection, as measured by significantly lower RNase P gene cycle threshold values, and that a Dacron polyester swab in PBS shows equivalent detection of SARS-CoV-2 and RSV to a flocked swab in VTM in contrived specimens. Diluted SARS-CoV-2-positive patient specimens are detectable for up to 72 h at 4 °C.
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Diagn. Microbiol. Infect. Dis. · Jan 2021
Pooling samples: a testing option for SARS-CoV-2 during a supply shortage.
Pooling of 1 positive sample with up to 5 negative samples prior to testing with the Cepheid GenXpert SARS-CoV-2 assay did not adversely impact detection of positive samples. At our current prevalence of 2%, it could save up to 70% of the test kits.