Journal of clinical microbiology
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J. Clin. Microbiol. · Dec 2020
Performance Evaluation of the SAMBA II SARS-CoV-2 Test for Point-of-Care Detection of SARS-CoV-2.
Nucleic acid amplification for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in respiratory samples is the standard method for diagnosis. The majority of this testing is centralized and therefore has turnaround times of several days. Point-of-care (POC) testing with rapid turnaround times would allow more effective triage in settings where patient management and infection control decisions need to be made rapidly. ⋯ The clinical performance was evaluated in 172 residual combined nose/throat swabs provided by the Clinical Microbiology and Public Health Laboratory, Addenbrooke's Hospital, Cambridge (CMPHL), which showed an estimated positive percent agreement of 98.9% (95% confidence interval [CI], 93.83 to 99.97) and negative percent agreement of 96.4% (95% CI, 89.92 to 99.26) compared to testing by the CMPHL. The data show that the SAMBA II SARS-CoV-2 test performs equivalently to the centralized testing methods, but with a shorter turnaround time of 86 to 101 min. Point-of-care tests such as SAMBA should enable rapid patient management and effective implementation of infection control measures.
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On 24 August 2020, the Centers for Disease Control and Prevention (CDC) updated its website to highlight that asymptomatic individuals, even those with exposure to a COVID-19-positive contact, do not necessarily need to be tested unless they have medical conditions associated with increased risk of severe illness from COVID-19. The CDC subsequently updated its guidance on 19 September 2020 to support testing of asymptomatic persons, including close contacts of persons with documented SARS-CoV-2 infection. ⋯ Limitations to consider when testing asymptomatic persons are covered, including the need to prioritize testing of contacts of positive COVID-19 cases. We urge the CDC to consult with primary stakeholders of COVID-19 testing when making such impactful changes in testing guidance.
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J. Clin. Microbiol. · Oct 2020
Comparative StudySelf-Collected Anterior Nasal and Saliva Specimens versus Health Care Worker-Collected Nasopharyngeal Swabs for the Molecular Detection of SARS-CoV-2.
We prospectively compared health care worker-collected nasopharyngeal swabs (NPS) to self-collected anterior nasal swabs (ANS) and straight saliva for the diagnosis of coronavirus disease 2019 (COVID-19) in 354 patients. The percent positive agreement between NPS and ANS or saliva was 86.3% (95% confidence interval [CI], 76.7 to 92.9%) and 93.8% (95% CI, 86.0 to 97.9%), respectively. The percent negative agreement was 99.6% (95% CI, 98.0 to 100.0%) for NPS versus ANS and 97.8% (95% CI, 95.3 to 99.2%) for NPS versus saliva. More cases were detected by the use of NPS (n = 80) and saliva (n = 81) than by the use of ANS (n = 70), but no single specimen type detected all severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections.
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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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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.