cbrueffer
commented
4 years ago Published as https://www.nature.com/articles/s41591-020-0913-5
Open allucas opened 4 years ago
cbrueffer
commented
4 years ago Published as https://www.nature.com/articles/s41591-020-0913-5
Title: A serological assay to detect SARS-CoV-2 seroconversion in humans
Please paste a link to the paper or a citation here:
Link: https://www.medrxiv.org/content/10.1101/2020.03.17.20037713v1
What is the paper's DOI?
DOI: https://doi.org/10.1101/2020.03.17.20037713
Please list some keywords (3-10) that help identify the relevance of this paper to COVID-19
Which areas of expertise are particularly relevant to the paper?
Questions to answer about each paper:
Please provide 1-2 sentences introducing the study and its main findings
The study describes a method for the detection of seroconversion upon SARS-CoV-2 infection based on the reactivity of the immunogenic spike protein (S protein) of the virus. The ELISA based assay is both sensitive and specific and capable for detecting COVID19 seroconverters, through plasma/serum samples, as early as 3 days post symptom onset.
Study question(s) being investigated:
What type of testing scenario is being considered?
It is a serological assay capable of detecting the generation of SARS-CoV-2 antibodies after initial viral infection. Detection of seroconversion is important for three main reasons: it allows for the study of the immune response to SARS-CoV-2 in a dynamic fashion, it allows to determine which individuals have already been exposed to the virus and have mounted an immune response (and therefore are non-contagious or they could serve as donors for the generation of convalescent serum therapeutics), and it allows to determine the precise rate of infection in a given region, providing better estimates of the true infection fatality rate.
Study population:
Human subjects
What is the model system (e.g., human study, animal model, cell line study)?
Human serum samples
What is the sample size?
59 banked human serum samples with previous exposure to viral infection (to generate an immune background as a control for the assay)
4 plasma/serum samples from three COVID-19 patients
What is the "pre-test" probability of disease in the study population (i.e., what is the anticipated prevalence of the disease?)
For human studies, the following are related to the pre-test probability:
What countries/regions are considered?
Control serum samples were acquired from individuals living in the US prior to the dissemination of COVID-19 within the US
COVID-19 samples were provided by the University of Melbourne and the University of Helsinki (no further information is provided from these subjects)
What is the age range, gender, other relevant characteristics?
For the control subjects: Ages ranged from 20-60+. Self-reported ethnicities include: Caucasian, Asian, African American, and Hispanic.
Previous viral exposure of the control subjects include: hantavirus, dengue virus, coronavirus NL63, and others.
COVID-19 Samples: Samples were obtained 2 and 6 days post symptom onset (for subject 3), 4 days post symptom onset (for subject 2), and 20 days post symptom onset (for subject 1)
What is the setting of the study (e.g., random sample of school children, retirement communities, etc.)?
What other specific inclusion-exclusion criteria are considered?
Reference test:
What reference test is considered as a "gold standard" comparator for the test under investigation?
Test assignment:
How are the new and reference tests assigned?
Examples of assignment could include: Recruited individuals have initially undergone neither the new nor the reference test; individuals tested as positive or negative by the reference test undergo the new test; individuals who have undertaken the new test are assessed by the standard test.
Are there any other relevant details about the study design?
Depending on how individuals are chosen, the test may be biasing towards more sick or less sick individuals or very clear-cut positive/negative cases. Any factors that would influence this bias should be included here.
Test conduct:
How were tests performed?
Describe technical details of assays used, when measurements were taken and by whom, etc. for both the new and standard tests.
Test Assessment
Describe how individuals are classified as positive or negative, e.g. if a threshold is used.
Is there evidence that the test is precise/reproducible when repeated more than once?
Are measurements complete?
For example: Do some participants undergo just one test (the new or the reference test)? Are there individuals with inconclusive results?
Results summary:
What are the estimated sensitivity, specificity, positive predictive value (PPV), and negative predicted value (NPV)?
Note that the PPV and NPV represent "post-test" probabilities of disease and are generally more meaningful than sensitivity and specificity. Sometimes the post-test odds will be given instead.
What are the confidence bounds around these intervals?
Interpretation of results for study population:
How good is the test at ruling in or ruling out a disease based on the post-test probabilities?
Are there identified side affects of the test?
Is patient adherence to the test likely to be an issue?
Extrapolation of conclusions to other groups of individuals
How well is the test likely to work in populations with different pretest odds?
For example, if the prevalence is lower, then the PPV will also be lower, but the NPV will be higher.
How costly is the test?
How difficult is it to perform the test in different settings?
Could the test be combined with other existing tests?
Summary of reliability
1-2 sentences on concluding remarks, including summary of strengths, weaknesses, limitations.
Progress
Check off the components as they are completed. If the component is not applicable, check the box as well.