Result for
Tag: testing
April 2, 2021
A Method for Detection of SARS-CoV-2 RNA in Healthy Human Stool: A Validation Study
A modified RT-PCR test to detect SARS-CoV-2 RNA in human stool had 100% analytical sensitivity in 20 stool samples freshly spiked with inactivated SARS-CoV-2 material and a lower limit of detection (LLD) of 3,000 viral RNA copies per gram. Analytical sensitivity decreased two-fold after a single freeze-thaw cycle at -80 °C. The assay had 100%…
March 31, 2021
A Haemagglutination Test for Rapid Detection of Antibodies to SARS-CoV-2
A study of red cell agglutination tests (haemagglutination tests, or HAT) demonstrated the ability to detect antibodies to the SARS-CoV-2 receptor binding domain with a sensitivity of 90% and a specificity of 99% in blood samples taken from individuals with a PCR-confirmed SARS-CoV-2 infection ≥28 days prior. The authors note that the HAT test for…
Diagnosis of SARS-CoV-2 Infection with LamPORE, a High-Throughput Platform Combining Loop-Mediated Isothermal Amplification and Nanopore Sequencing
A novel diagnostic platform called Loop-Mediated Isothermal Amplification with Nanopore Sequence (LamPORE) performed similarly to RT-PCR for detection of SARS-CoV-2 in nasopharyngeal samples collected at two hospitals in the United Kingdom. The diagnostic method can process up to 92 samples simultaneously and allow for analysis of thousands of pooled samples per day. In the study,…
March 30, 2021
Performance and Operational Feasibility of Antigen and Antibody Rapid Diagnostic Tests for COVID-19 in Symptomatic and Asymptomatic Patients in Cameroon: A Clinical, Prospective, Diagnostic Accuracy Study
A novel testing algorithm combining RT-PCR and antigen rapid diagnostic testing developed in Cameroon had 94% sensitivity and 91% specificity for detection of symptomatic SARS-CoV-2 infection within 7 days of symptom onset and outperformed PCR testing alone (75% sensitivity and 99% specificity). The algorithm was designed based on retrospectively performing 1000 simulation runs on empirical…
March 25, 2021
Detection of Mutations Associated with Variants of Concern Via High Throughput Sequencing of SARS-CoV-2 Isolated from NYC Wastewater
[Pre-print, not peer-reviewed] Genomic analysis of wastewater samples from New York City obtained from January to March 2021 found that the SARS-CoV-2 mutations occurring at the highest frequencies where associated with known variants of concern. Mutations occurring at high frequencies include L452R, present in the CAL.20C variant first described in California, E484K, present in the…
March 23, 2021
Surveillance-Based Informative Testing for Detection and Containment of SARS-CoV-2 Outbreaks on a Public University Campus: An Observational and Modelling Study
A novel strategy of random testing combined with follow-up targeted testing in outbreak areas (“surveillance-based informative testing”, SBIT) was associated with a 36% reduction in peak weekly COVID-19 cases at Clemson University in South Carolina over a 2-week period. The strategy helped identify outbreaks in 45 residence halls across 8 buildings. Transmission models based on…
March 17, 2021
Real-World Experience of SARS-CoV-2 Antibody Assays in UK Healthcare Workers
Among health care workers in the UK, Abbott and Roche antibody assays showed low sensitivity for detecting individuals with previous PCR-confirmed infection. In a cohort study conducted at 2 medical centers in the UK, the Abbott antibody assay had a sensitivity (proportion with a positive antibody test result in those with previous PCR-confirmed infection) of…
Nasopharyngeal Panbio COVID-19 Antigen Performed at Point-of-Care Has a High Sensitivity in Symptomatic and Asymptomatic Patients With Higher Risk for Transmission and Older Age
Performance of the nasopharyngeal Panbio COVID-19 antigen (Ag) test was highly dependent on the cycle threshold (Ct) value. The Panbio test showed high sensitivity among older, symptomatic patients with a cycle threshold (Ct) value below 30 (indicating higher viral load). The positive percent agreement (PPA) relative to RT-PCR of 94% for Ct at ≤25 and…
Clinical Evaluation of Roche SD Biosensor Rapid Antigen Test for SARS-CoV-2 in Municipal Health Service Testing Site, the Netherlands
Evaluation of the Roche SD Biosensor rapid antigen test for SARS-CoV-2 among asymptomatic outpatients demonstrated that test sensitivity was 84.9% and specificity was 99.5%. Around 98% of samples with a cycle threshold (Ct) below 30 (indicating higher viral load) were detected. Test sensitivity was higher (95.8%) among people who sought care within 7 days of…
March 15, 2021
Specific Allelic Discrimination of N501Y and Other SARS-CoV-2 Mutations by DdPCR Detects B.1.1.7 Lineage in Washington State
[Pre-print, not peer-reviewed] A research team in Washington State described detection of the first cases of the B.1.1.7 SARS-CoV-2 variant in the state using a novel droplet reverse transcriptase digital-PCR (RT-ddPCR) assay that detects four mutations associated with the B.1.1.7 lineage. All four targets were detected in two specimens, and follow-up sequencing revealed 10 mutations…
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