Result for
Tag: testing
April 9, 2021
The Impact of Changes in Diagnostic Testing Practices on Estimates of COVID-19 Transmission in the United States
Trends over time and changes in the level of SARS-CoV-2 diagnostic testing and reporting practices can bias the estimates of the basic reproductive number (R0), an estimate of transmission. An increasing R0 could be overestimated if the proportion of cases captured increases over time, which can be affected by changes in testing eligibility and an…
COVID-19 Stats: College and University COVID-19 Student Testing Protocols, by Mode of Instruction (N = 1,849) — United States, Spring 2021
As of March 17, 2021, a total of 899 (49%) of 1,849 public and private nonprofit 4-year U.S. colleges and universities provided some type of COVID-19 testing for asymptomatic students. A total of 548 (30%) institutions conducted classes in-person or in a hybrid format. At 389 (43%) institutions there were protocols that required periodic testing…
Ultra-Sensitive Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Antigen Detection for the Diagnosis of Coronavirus Disease 2019 (COVID-19) in Upper Respiratory Samples
A study of a newly developed ultra-sensitive assay for detection of SARS-CoV-2 (S-PLEX, MesoScale Diagnostics) in upper respiratory samples (N=450) with a cycle threshold <35 (higher concentration of virus) demonstrated 95-98% positive agreement and 93-96% negative agreement with RT-PCR. This study confirmed the findings of a previous study of the assay that was performed on…
Factors Associated with Participation in Elementary School–Based SARS-CoV-2 Testing — Salt Lake County, Utah, December 2020–January 2021
An evaluation of an elementary school-based testing program for school contacts of persons with laboratory-confirmed SARS-CoV-2 infection in Salt Lake County, UT (N=856) found that students of White, Hispanic and other racial minority groups and those residing in zip codes with higher SARS-CoV-2 prevalence were more likely to consent to testing. No differences were found…
April 8, 2021
Differences in COVID-19 Testing and Test Positivity Among Veterans, United States, 2020
US Veterans who are female, from racial/ethnic minority groups, had a low income, or had a service-related disability were more likely to obtain a COVID-19 test according to a retrospective cohort study with over 6 million veterans across 130 Veterans Health Administration facilities. Among veterans who were tested, those who identify as African American or…
April 7, 2021
SARS-CoV-2 Is Detectable Using Sensitive RNA Saliva Testing Days before Viral Load Reaches Detection Range of Low-Sensitivity Nasal Swab Tests
[Pre-print, not peer-reviewed] A case-control study that collected twice-daily self-collected samples from household contacts of individuals recently diagnosed with a SARS-CoV-2 infection found that SARS-CoV-2 RNA was first detectable in saliva samples and subsequently detectable in samples from nasal swabs. The study found that high-sensitivity tests that use saliva can detect SARS-CoV-2 infection 1.5 to…
Real World Assessment of SARS-CoV-2 Nasopharyngeal Swab Testing in a High Burden COVID-19 Region
An observational analysis of hospitalized US patients who were retested for SARS-CoV-2 due to high clinician concern for a potential false-negative found that 7/160 (4.4%) patients with an initial negative nasopharyngeal PCR test had a subsequent positive test within 48 hours. The authors conclude that routine retesting for SARS-CoV-2 is not indicated and should only…
April 6, 2021
SLAMP A Rapid Fluorometric RT-LAMP Assay for Sensitive and Specific Detection of SARS-CoV-2 from Human Saliva
[Pre-print, not peer-reviewed] SLAMP, a novel RT-LAMP (reverse transcriptase loop-mediated isothermal amplification) assay applied to heat-inactivated saliva samples, demonstrated 91% sensitivity at 98% specificity compared to RT-PCR using nasopharyngeal swab samples among 243 individuals (65 SARS-COV-2 positive). Bikos et al. (Apr 5, 2021). SLAMP A Rapid Fluorometric RT-LAMP Assay for Sensitive and Specific Detection of SARS-CoV-2…
April 5, 2021
Persistence of Anti-SARS-CoV-2 Antibodies Depends on the Analytical Kit: A Report for Up to 10 Months after Infection
A study of hospitalized and non-hospitalized symptomatic patients (n = 210 samples, 84 patients) over a period of 10 months using six different commercial assays for antibody detection found that assays targeting total antibodies presented higher positivity rates and reached the highest positivity rates sooner than assays directed against IgG alone. The inter-assay agreement was…
COVID-19 Rapid Antigen Test as Screening Strategy at Points of Entry: Experience in Lazio Region, Central Italy, August–October 2020
Between mid-August to mid-October 2020, 1,176 of 73,643 rapid antigen test results (1.6%) were positive for travelers at points of entry in the Lazio Region of Italy via the STANDARD F COVID-19 Ag FIA, but only 40.5% antigen-positive samples also tested positive by RT-PCR. Antigen tests with a higher semiquantitative result were more likely to…
Previous page Next page