Journal of clinical microbiology
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J. Clin. Microbiol. · Dec 2020
Comparative StudyComparison of the Clinical Performances of the Abbott Alinity IgG, Abbott Architect IgM, and Roche Elecsys Total SARS-CoV-2 Antibody Assays.
Critical evaluation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serologic assays is needed to guide clinical decision-making and ensure that these assays provide optimal benefit to patients and the public. Here, three commercially available assays with widespread distribution capabilities are compared. A total of 667 specimens, 103 from patients with confirmed SARS-CoV-2 infections and 564 collected prior to the emergence of SARS-CoV-2, were analyzed in parallel using the Roche Elecsys SARS-CoV-2 total antibody and Abbott Alinity SARS-CoV-2 IgG assays; a subset of 55 samples from patients with confirmed SARS-CoV-2 infections was additionally evaluated using the Abbott Architect SARS-CoV-2 IgM assay. ⋯ Among 51 patients with confirmed SARS-CoV-2 infections, 23 (45.1%), 24 (47.1%), and 22 (43.1%) were reactive by the Abbott IgG, Roche total antibody, and Abbott IgM assays, respectively, with sampling times 0 to 56 days post-positive PCR (median/mean, 2/6.2 days). Combining IgG and IgM screening identified 4/55 additional samples with detectable antibodies that would not have been observed using the assays independently. Notably, one immunocompromised patient with confirmed SARS-CoV-2 infection showed no detectable antibodies using any of the three assays 43 days after onset of symptoms.
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J. Clin. Microbiol. · Dec 2020
Comparative StudyClinical Evaluation of BD Veritor SARS-CoV-2 Point-of-Care Test Performance Compared to PCR-Based Testing and versus the Sofia 2 SARS Antigen Point-of-Care Test.
The clinical performance of the BD Veritor System for Rapid Detection of SARS-CoV-2 nucleocapsid antigen (Veritor), a chromatographic immunoassay used for SARS-CoV-2 point-of-care testing, was evaluated using nasal specimens from individuals with COVID-19 symptoms. Two studies were completed to determine clinical performance. In the first study, nasal specimens and either nasopharyngeal or oropharyngeal specimens from 251 participants with COVID-19 symptoms (≤7 days from symptom onset [DSO], ≥18 years of age) were utilized to compare Veritor with the Lyra SARS-CoV-2 PCR assay (Lyra). ⋯ Veritor met FDA emergency use authorization (EUA) acceptance criteria for SARS-CoV-2 antigen testing for the 0 to 5 and 0 to 6 DSO ranges (PPA values of 83.9% and 82.4%, respectively). Veritor and Sofia 2 showed a high degree of agreement for SARS-CoV-2 detection. The Veritor test allows for more rapid COVID-19 testing utilizing easy-to-collect nasal swabs but demonstrated <100% PPA compared to PCR.
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J. Clin. Microbiol. · Oct 2020
Comparative StudyA Direct Comparison of Enhanced Saliva to Nasopharyngeal Swab for the Detection of SARS-CoV-2 in Symptomatic Patients.
The ongoing coronavirus disease 2019 (COVID-19) pandemic has resulted in shortages of nasopharyngeal swabs (NPS) and viral transport media, necessitating the search for alternate diagnostic specimens, such as saliva. We directly compared matched saliva and NPS specimens from symptomatic patients suspected of having COVID-19. An enhanced saliva specimen (i.e., strong sniff, elicited cough, and collection of saliva/secretions) was collected without transport medium prior to collection of NPS from 224 patients with symptoms deemed consistent with COVID-19. ⋯ The one discrepant specimen had the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) confirmed in the saliva specimen using an alternate FDA EUA assay. The overall mean difference in cycle threshold (CT ) values for the positive NPS and saliva specimens was -3.61 (95% confidence interval [CI], -5.78 to -1.44; P = 0.002). An enhanced saliva specimen performed as well as NPS for the qualitative detection of SARS-CoV-2 in symptomatic patients, although the overall mean viral load in saliva was lower.
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J. Clin. Microbiol. · Oct 2020
SARS-CoV-2 Assays To Detect Functional Antibody Responses That Block ACE2 Recognition in Vaccinated Animals and Infected Patients.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic of COVID-19, resulting in cases of mild to severe respiratory distress and significant mortality. The global outbreak of this novel coronavirus has now infected >20 million people worldwide, with >5 million cases in the United States (11 August 2020). The development of diagnostic and research tools to determine infection and vaccine efficacy is critically needed. ⋯ In addition, we employ the assay to measure receptor blocking of sera from SARS-CoV-2-infected patients. The assay is shown to correlate with pseudovirus neutralization titers. This type of rapid, surrogate neutralization diagnostic can be employed widely to help study SARS-CoV-2 infection and assess the efficacy of vaccines.
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Frequent, low-cost, universal testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with quarantine of those with a positive result has been suggested as a strategy to address the coronavirus disease 2019 (COVID-19) pandemic in the United States. Specifically, home or community use of tests that use paper strip detection devices, which may have reduced sensitivity for SARS-CoV-2, has been advocated. ⋯ Because of these, we think it is premature to strongly advocate for such a testing strategy, as the adverse consequences may outweigh any benefits. High-quality outcome data demonstrating the efficacy of this testing strategy are needed before widespread implementation.