Result for
Tag: testing
May 10, 2021
Precision Health Diagnostic and Surveillance Network Uses S Gene Target Failure (SGTF) Combined with Sequencing Technologies to Identify Emerging SARS-CoV-2 Variants
[Pre-print, not peer-reviewed] A genomic surveillance algorithm developed to combine RT-PCR and sequencing technologies to identify SARS-CoV-2 variants of concern found the frequency of S Gene Target Failure (SGTF) exponentially to 47% and 48% by the last week of March 2021, in both Puerto Rico and US laboratories, respectively. SGTF is used as a proxy…
May 7, 2021
Performance of Unobserved Self-Collected Nasal Swabs for Detection of SARS-CoV-2 by RT-PCR Utilizing a Remote Specimen Collection Strategy
A large, retrospective study (N=47,000) comparing unobserved self-collected anterior nasal swabs and healthcare provider-collected nasopharyngeal swabs found that cycle threshold values for detection of human RNase P (RP), an indicator of sample adequacy for RT-PCR testing, were not significantly different. However, cycle thresholds for detection of SARS-CoV-2 were significantly higher for self-collected than provider-collected swabs,…
May 6, 2021
Implementation of SARS-CoV2 Screening in K-12 Schools Using In-School Pooled Molecular Testing and Deconvolution by Rapid Antigen Test
[Pre-print, not peer-reviewed] Large-scale implementation of pooled testing for routine screening of asymptomatic SARS-CoV-2 infection was demonstrated to be feasible across 592 schools in Massachusetts between January and April 2021. During the study period, 259,726 individuals were tested across 50,636 pools (mean swabs per pool = 7) with a median turnaround time of 21 hours….
May 5, 2021
A High-Throughput Microfluidic Nanoimmunoassay for Detecting Anti–SARS-CoV-2 Antibodies in Serum or Ultralow-Volume Blood Samples
A microfluidic nanoimmunoassay to detect anti-SARS-CoV-2 IgG antibodies achieved a sensitivity of 98% and specificity of 100% based on an analysis of 134 pre-pandemic sera and 155 sera from PCR-confirmed individuals. The assay relies on a repurposed blood from a glucose test strip (finger prick) and other low-cost blood sampling methods to eliminate the need…
Salivary Testing of COVID-19: Evaluation of Serological Testing Following Positive Salivary Results
In a study including 46 patients who received a positive PCR test either by nasopharyngeal swab (NPS) or saliva swab and had recovered from asymptomatic and mild SARS-CoV-2 infection, 42 (91%) tested positive for anti-SARS-CoV-2 spike antibodies after a median of 145 days of follow-up. Caulley et al. (May 4, 2021). Salivary Testing of COVID-19: Evaluation…
May 4, 2021
Factors Associated With Access to and Timing of Coronavirus Testing Among US Adults After Onset of Febrile Illness
In a study of 2,679 US participants reporting new onset of fever from April 2020 to October 2020, only 17% indicated ever taking a SARS-CoV-2 test within 2 weeks of symptom onset, and only 12% indicated receiving a result. Among those who received a SARS-CoV-2 test result, only 21% received their test result within 7…
Implications in the Quantification of SARS-CoV2 Copies in Concurrent Nasopharyngeal Swabs, Whole Mouth Fluid and Respiratory Droplets
In a study of 55 patients with SARS-CoV-2 PCR-positive nasopharyngeal (NPS) swabs, whole mouth fluid (WMF) samples had detectable SARS-CoV-2 RNA in 44 (80%) patients and had overall similar viral loads compared to NPS samples. Patients with severe disease course produced WMF samples with significantly higher virus copies. The authors suggest indicates that WMF, which…
May 3, 2021
Comparative Diagnostic Performance of Different Rapid Antigen Detection Tests for COVID-19 in the Real-World Hospital Setting
A comparison of the diagnostic performance of seven antigen-detecting rapid diagnostic tests (Ag-RDTs, both lateral flow immunochromatographic tests and fluorescent immunoassay tests) in real-world hospital settings found a wide range of sensitivity estimates by test brand (range 66.0–93.8%) and cycle threshold (Ct) cut-off values (Ct < 25: 96.2%; Ct 30-35: 31.1%), with an optimal Ct…
April 30, 2021
SARS-CoV-2 Detection on Self-Collected Saliva or Anterior Nasal Specimens Compared with Healthcare Personnel-Collected Nasopharyngeal Specimens
A study of 730 adults undergoing simultaneous nasopharyngeal (NPS), anterior nasal (ANS), and saliva specimen collection for SARS-CoV-2 testing found the sensitivity for saliva testing was 85% and sensitivity for ANS testing was 80%, which increased to 100% and 94%, respectively, among participants with culture-positive SARS-CoV-2 by any specimen type. Saliva (37%) and ANS (46%)…
Head-to-Head Evaluation of Five Automated SARS-CoV-2 Serology Immunoassays in Various Prevalence Settings
A comparison of five automated SARS-CoV-2 serology tests found that the Euroimmun and Roche assays (either the assay targeting the nucleocapsid (N) or spike protein (S) antigens) performed equally well without the need for additional confirmatory testing in high prevalence settings compared to the gold standard of rRT-PCR and rIFA. However, the authors suggest that…
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