Result for
Tag: testing
March 11, 2021
Follow-up Testing of Borderline SARS-CoV-2 Patients by RRT-PCR Allows Early Diagnosis of COVID-19
Follow-up testing of “borderline” PCR test results within 96 hours occasionally identified additional positive results, according to a retrospective analysis of over 30,000 SARS-CoV-2 PCR test results (1,092 positive). Of the 204 borderline results, which had viral amplification just below the positivity threshold (>25 viral copies/mL), 107 were re-tested and 10 were found positive, representing…
March 10, 2021
Modeling Transmission Dynamics and Effectiveness of Worker Screening Programs for SARS-CoV-2 in Pork Processing Plant
[Pre-print, not peer-reviewed] A modeling study of SARS-CoV-2 transmission and screening programs in pork processing facilities during spring 2020 found that the effectiveness of routine PCR-screening at minimizing disease spread was influenced more by testing frequency than delays in results, the initial reproduction number, or background community transmission rates. While testing every three days prevented ~25-…
March 9, 2021
Clinical and Economic Effects of Widespread Rapid Testing to Decrease SARS-CoV-2 Transmission
A transmission model calibrated to the US population suggests that implementing weekly home-based SARS-CoV-2 antigen testing could avert 2.8 million infections and 15,700 deaths over 60 days. In contrast, a scenario with no testing anticipates 11.6 million infections and 119,000 deaths over the same time period. While the scenario with testing could cost an additional…
Performance of National COVID-19 ‘Symptom Checkers’: A Comparative Case Simulation Study
Using simulated patients designed to have signs and symptoms consistent with typical COVID-19 presentations as well as patients with conditions that can mimic COVID-19 (e.g. sepsis and bacterial pneumonia), the CDC Coronavirus Symptom Checker only successfully triaged 38% of cases to seek further health assessment. In contrast, the corresponding symptom checkers used in the UK,…
A Rapid Method to Evaluate Pre-Travel Testing Programs for COVID-19 A Study in Hawaii
[Pre-print, not peer-reviewed] A rapid field study conducted in the Kahului main airport in Maui, Hawaii identified 2 SARS-CoV-2 PCR positive participants out of 279 consecutively sampled participants boarding for departure, despite all participants having a negative PCR test 72 hours prior. This positivity rate corresponded to 7 cases per 1,000 travelers, which corresponds to…
March 8, 2021
Rapid Increase of SARS-CoV-2 Variant B.1.1.7 Detected in Sewage Samples from England between October 2020 and January 2021
[Pre-print, not peer-reviewed] Between October 2020 and January 2021, a rapid increase in the SARS-CoV-2 variant B.1.1.7 was detected in sewage samples in England. Viral RNA containing B.1.1.7 mutations was first identified in a sample collected in London on November 10 and detected in 7-9% of all sewage samples in November, increasing to >95% by January…
Diagnosis of SARS-Cov-2 Infection by RT-PCR Using Specimens Other Than Naso- and Oropharyngeal Swabs: A Systematic Review and Meta-Analysis
A systematic review and meta-analysis of SARS-CoV-2 RT-PCR testing using samples other than naso- or oropharyngeal swabs found that saliva samples had the highest accuracy (92%), with a sensitivity of 84% and specificity of 96%. Deep throat saliva/posterior oropharyngeal saliva samples had an overall accuracy of 80%, with a sensitivity of 90% and specificity of…
March 4, 2021
Sars-Cov-2 Infection in Uk University Students: Lessons from September-December 2020 and Modelling Insights for Future Student Return
[Pre-print, not peer-reviewed] A modeling study suggests that student adherence to testing and isolation is likely to contribute more to reducing SARS-CoV-2 transmission than staggering return dates, based on data from the first term of the 2020/2021 academic year in universities in the UK. The authors suggest that in the presence of the more transmissible…
March 3, 2021
Comparative Performance of SARS-CoV-2 Lateral Flow Antigen Tests Demonstrates Their Utility for High Sensitivity Detection of Infectious Virus in Clinical Specimens
[Pre-print, not peer-reviewed] A comparison of six commercial rapid antigen lateral flow devices (LFDs) using combined nasal/oropharyngeal swabs obtained from clinical specimens demonstrated sensitivities ranging from 65% to 89%. Sensitivity increased in most tests to over 90% for samples with cycle threshold (Cts) lower than 25 (higher viral concentrations) and most had a high specificity…
March 1, 2021
Assessing the Readability of Covid-19 Testing Messages on the Internet
Only 6 out of the first 50 results using a Google search for “COVID-19 testing” had an appropriate readability score. Of these six, two were deemed appropriate by 3 tests (Flesch-Kincaid Grade Level (FKGL), Gunning Fog Index (GFI), and Coleman-Liau Index (CLI)) and four were deemed appropriate by 2 tests (FKGL and GFI). None of…
Previous page Next page