ABSTRACT
Background. Rapid COVID-19 tests can offer significant advantages and reduce health disparities. The LumiraDx SARS-CoV-2 platform can perform microfluidic fluorescence assays for the rapid detection of SARS-CoV-2 antigen (Ag) and antibodies (Ab). We evaluated both tests in a longitudinal cohort to evaluate performance during acute SARS-CoV-2 infection and recovery. Methods. We collected nasal samples from 71 unique participants at four clinic visits spanning 0-21 days since symptom onset (DSSO);blood samples were collected from the same participants over six visits spanning 0-87 DSSO. For Ag testing, 232 anterior nasal swabs were assayed by: 1) the LumiraDx Ag test, 2) a laboratory-based electrochemiluminescence immunoassay for N Ag, 3) RT-PCR (Hologic Panther Fusion), and 4) culture (growth in VeroE6AT cells). For Ab testing, 308 serum samples were assayed by: 1) the LumiraDx Ab test and 2) Roche Elecsys Anti-S SARS-CoV-2 total Ab test. Measures of concordance [positive predictive agreement (PPA), negative predictive agreement (NPA), and Cohen's Kappa (K)] were estimated for qualitative results of the LumiraDx tests versus corresponding lab reference tests. Confidence intervals were estimated via bootstrapping. Results. LumiraDx Ag results had strong agreement with lab N-Ag results (K > 0.80) across all samples. Between 0-5 days, agreement was perfect, except for one sample resulting positive by LumiraDx Ag and negative by lab Ag. Agreement with PCR results was moderate overall (K=0.60), though substantial (K > 0.6) for both 0-5 DSSO (PPA=0.96/NPA=0.80) and 6-10 DSSO (PPA=0.96/NPA=0.59). Agreement with culture results was moderate overall (K=0.46): substantial (K=0.6) between 0-5 DSSO (PPA=0.96/NPA=0.60) and fair (K=0.29) between 6-10 DSSO (PPA=1.0/NPA=0.32). LumiraDx Ab results showed almost perfect agreement with lab Ab results across all samples (K=0.88), with substantial agreement (K > 0.7) for samples collected 0-10 DSSO (PPA=0.93/NPA=0.89) and 11-28 DSSO (PPA=0.99/NPA=0.69). Longitudinal agreement of LumiraDx antigen test result and culture positivity, by PCR Ct value. Nasal samples grouped by participant (lines) and agreement of results between LumiraDx antigen test result and culture positivity (proxy for infectiousness). Conclusion. LumiraDx rapid tests perform well compared to more costly and time-consuming lab methods of Ag and Ab detection. The rapid Ag test may be helpful in identifying patients infectious between 0-5 DSSO, given the substantial concordance of the rapid Ag test and culture positivity.
ABSTRACT
Background. Appropriate diagnostic testing can be used to inform infection control measures and reduce SARS-CoV-2 transmission, yet the test kinetics, infectivity, and immunological responses during acute, non-severe SARS-CoV-2 infection need clarity. Methods. We conducted a prospective cohort study between Nov 2020-July 2021 in Seattle, Washington of 95 unvaccinated, immunocompetent adults with no prior SARS-CoV-2 infection. Nasal swabs (nasopharyngeal and anterior) and blood serum samples were serially collected at six visits over two months. Viral RNA, N and S antigen concentrations, and viral growth/infectivity were measured from nasal samples. Anti-S total antibody and IgG assays were performed on serum. We fit loess curves to quantitative data corresponding to each testing modality by days since symptom onset (DSSO) and compared qualitative test results across time points to demonstrate timedependent agreement of PCR, N antigen, and culture results. Generalized estimating equations were used to approximate relative risk of culture positivity (a proxy for infectiousness) for positive vs. negative test results (antigen and PCR), stratified by presence/ absence of symptoms and DSSO. Sampling Schema Nasal swabs and venous blood were collected at visits 1-4;venous blood only at visits 5-6. All participants were enrolled within 14 days of symptom onset (median: 6) and 7 days of a positive test (median: 4). Results. Infections in this cohort (median age: 29y) were mild (no hospitalization). Median (IQR) time to negative result was 11 (4), 13 (6), and 20 (7) DSSO for culture growth, N antigen, and PCR tests, respectively. Viral RNA quantities declined more slowly than antigen and culturable virus;antibody titers rose rapidly 5-15 DSSO and plateaued 20-30 DSSO. All culture-positive samples collected 0-5 DSSO were positive by PCR, but relative risk of culture positivity (infectiousness) for positive vs. negative PCR results declined 6-10 DSSO. Relative risk of culture positivity for positive vs. negative antigen results was consistently high 0-10 DSSO, with similar results when stratified by presence of symptoms. Diagnostic test kinetics and immunological responses Diagnostic test kinetics and immunological responses measured in adults with non-severe, symptomatic SARS-CoV-2 infection: loess trendlines and 95% confidence intervals are given for SARS-CoV-2 viral load (calculated from PCR Ct value using a calibration curve), TCID50 from viral culture, mean concentrations of nucleocapsid and spike antigen proteins, and anti-S total and IgG antibody concentrations. Conclusion. The results reinforce the importance of molecular PCR testing as a highly sensitive diagnostic tool but with limited utility as an indicator of viral culturability and likely infectiousness. N antigen testing may be a preferable diagnostic test within two weeks of symptom onset, especially 6-10 DSSO, because it more closely correlates with culture growth over the course of infection.
ABSTRACT
Health is consistently a significant worry in each development humanity is progressing regarding innovation. Like the new COVID assault that has destroyed the economy of China to a degree is a model how medical services have happened to significant significance. In such territories where the plague is spread, it is consistently a superior thought to screen these patients utilizing distant well-being observing innovation. This scheme is answerable for gathering beat, internal heat level and heart beat from the patient’s body and send the information into IoT Cloud stage by utilizing Wi-Fi-module and ailment of patient put away in the cloud. It empowers the clinically trained professional or approved individual to screen patient’s well-being, where the clinical subject matter expert or approved individual can constantly screen the patient’s condition on the cloud worker. In our new scheme, the conclusion is to produce effective and health services to patients. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
ABSTRACT
Designers from around the world have proposed numerous engineering design solutions for problems related to the COVID-19 pandemic, many of which leverage the rapid prototyping and manufacturing capabilities of additive manufacturing (AM). While some of these solutions are motivated by complex and urgent requirements (e.g., face masks), others are motivated by simpler and less urgent needs (e.g., hands-free door openers). Previous research suggests that problem definition influences the creativity of solutions generated for the problem. In this study, we investigate the relationship between the definition of problems related to the COVID-19 pandemic and the characteristics of AM solutions that were openly shared for these problems. Specifically, we analyze 26 AM solutions spanning three categories: (1) hands-free door openers (low complexity problem), (2) face shields (moderate complexity problem), and (3) face masks (high complexity problem). These designs were compared on (1) DfAM utilization, (2) manufacturability (i.e., build time, cost, and material usage), and (3) creativity. We see that the solutions designed for the high complexity problem, i.e., face masks, were least suitable for AM. Moreover, we see that solutions designed for the moderate complexity problem, i.e., face shields, had the lowest build time, build cost, and material consumption. Finally, we observe that the problem definition did not relate to the creativity of the AM solutions. In light of these findings, designers must sufficiently emphasize the AM suitability and manufacturability of their solutions when designing for urgent and complex problems in rapid response situations. © 2021 International Union of Crystallography. All rights reserved.