Result for
Topic: Testing and Treatment
July 20, 2020
Going beyond Clinical Routine in SARS-CoV-2 Antibody Testing – A Multiplex Corona Virus Antibody Test for the Evaluation of Cross-Reactivity to Endemic Coronavirus Antigens
[pre-print, not peer-reviewed] Becker et al. developed a multiplexed immunoassay to measure IgG and IgA responses against six SARS-CoV-2 antigens, achieving a sensitivity of 90% and a specificity of 100%. By monitoring IgA response, they were able to detect an early immune response in some patients. The authors suggest that the test may be useful in monitoring vaccination studies and conducting…
Seroprevalence of SARS-CoV-2 Antibodies in an Entirely PCR-Sampled and Quarantined Community after a COVID-19 Outbreak – the CoNAN Study
[pre-print, not peer-reviewed] Screening for SARS-CoV-2 by RT-PCR and antibody testing in a village in Germany that had been quarantined for six weeks after a SARS-CoV-2 outbreak found that only 53% of participants with previously confirmed SARS-CoV-2 infections had detectable antibodies. Overall, 8% of the inhabitants had a positive SARS-CoV-2 antibody test (based on two or…
Self-Collected Anterior Nasal and Saliva Specimens versus Healthcare Worker-Collected Nasopharyngeal Swabs for the Molecular Detection of SARS-CoV-2
[pre-print, not peer-reviewed] Hanson et al. compared healthcare worker-collected nasopharyngeal swabs (NPS) to self-collected anterior nasal swabs (ANS) and saliva for diagnosis of SARS CoV-2 infection in adults accessing drive through testing (n=268). The positive percent agreement between NPS and ANS or saliva was 86.3% and 93.8%, respectively. Negative percent agreement was 99.6% for NPS vs. ANS and…
July 17, 2020
SARS-CoV-2 Viral Load Assessment in Respiratory Samples
Kleiboecker et al. report the distribution of viral loads in a large number of SARS-CoV-2-positive respiratory samples (n=4,428). Fifteen percent of samples had extremely high virus levels (>8 log10 copies/ml), while low viral loads (<1000 copies/ml) were relatively common (10%). Neither age nor gender were meaningfully associated with mean and median viral load. The authors also review challenges in comparing viral load values between studies. Kleiboeker et al. (May 2020). SARS-CoV-2 Viral Load Assessment in…
Hydroxychloroquine in Nonhospitalized Adults With Early COVID-19: A Randomized Trial
Skipper et al. report findings of a randomized, double-blind placebo-controlled trial of oral hydroxychloroquine (800mg once, followed by 600mg in 6-8 hours, then 600mg daily for 4 days) among symptomatic non–hospitalized adults with laboratory-confirmed COVID-19 or probable COVID-19 (n=423). Patients in the hydroxychloroquine arm had a non-significantly lower probability of ongoing symptoms at 14 days (24% versus 30%; p=0.21). There…
July 16, 2020
Smart Pooling AI-Powered COVID-19 Testing
[Pre-print, not peer reviewed] Escobar et al. developed a pooling method for SARS-CoV-2 testing protocols that uses machine learning to predict the probability of a negative result from sociodemographic data. The technique was most efficient at lower disease prevalence, and showed efficiency gains of 42% with respect to individual testing at disease prevalence up to 25%. Escobar et al. (July 15,…
Presymptomatic Transmission of SARS-CoV-2 Amongst Residents and Staff at a Skilled Nursing Facility: Results of Real-Time PCR and Serologic Testing
Universal testing of a skilled nursing facility without a known case of COVID-19 in Massachusetts revealed an 85% prevalence of COVID-19 among residents (n=97) and 37% among participating staff (n=97) during a serial testing program over approximately one week. The facility had universal masking, temperature checks and symptom screen procedures in place for staff for at least two weeks prior to…
July 15, 2020
SARS-CoV-2 Antibody Responses Do Not Predict COVID-19 Disease Severity
Based on a sample of 172 suspected cases of SARS-CoV-2 and 795 negative plasma samples, IgG antibody testing had a 100% specificity (0/795) and IgG tests were positive for 83% of suspected cases among samples collected more than 14 days from symptom onset. There was no association between the level of IgG and IgM reactivity and mild versus severe disease course. Phipps et al. (July 15, 2020)….
At What Times during Infection Is SARS-CoV-2 Detectable and No Longer Detectable Using RT-PCR Based Tests A Systematic Review of Individual Participant Data
[Preprint, not peer-reviewed] A systematic review (32 studies with 1,023 SARS-CoV-2 infected patients) showed the highest percentage of detection of SARS-CoV-2 by RT-PCR was from nasopharyngeal sampling between 0 to 4 days post-symptom onset at 89% (95%CI 83%-93%). The percentage dropped to 54% (95%CI 47%-61%) after 10 to 14 days. Up to 30% of participants with SARS-CoV-2 detected in respiratory samples did not have detectable…
Significantly Improved COVID-19 Outcomes in Countries with Higher BCG Vaccination Coverage: A Multivariable Analysis
An ecological study conducted by Klinger et al. find a strong negative correlation between the years of BCG administration and the deaths per million from COVID-19 based on data from 55 countries. Countries with BCG immunization policies over the past 15 years have a significantly lower rate of COVID-19 deaths than countries with no BCG in last 15 years (p=0.0004). [EDITORIAL NOTE: Results from ecological…
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