scholarly journals Evaluation of the performance of SARS-CoV-2 antibody assays for the longitudinal population-based study of COVID-19 spread in St. Petersburg, Russia

2021 ◽  
Author(s):  
Anton Barchuk ◽  
Daniil Shirokov ◽  
Mariia Sergeeva ◽  
Rustam Tursun-zade ◽  
Olga Dudkina ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Antibody Test ◽  
Population Based ◽  
Enzyme Linked Immunosorbent Assay ◽  
Population Based Study ◽  
Clinical Sensitivity ◽  
Study Results ◽  
Antibody Assays ◽  
Antibody Tests ◽  
Abbott Architect

Background: An evident geographical variation in the SARS-CoV-2 spread requires seroprevalence studies based on local tests with robust validation against already available antibody tests and neutralization assays. This report summarizes the evaluation of antibody tests used in the representative population-based serological study of SARS-CoV-2 in Saint Petersburg, Russia. Methods: We used three different antibody tests throughout the study: chemiluminescent microparticle immunoassay (CMIA) Abbott Architect SARS-CoV-2 IgG, Enzyme-linked immunosorbent assay (ELISA) CoronaPass total antibodies test, and ELISA SARS-CoV-2-IgG-EIA-BEST. Clinical sensitivity was estimated with the SARS-CoV-2 PCR test as the gold standard and specificity in pre-pandemic sera samples using the cut-off recommended by manufacturers. Paired and unpaired serum sets were used. Measures of concordance were also calculated in the seroprevalence study sample against the microneutralization test (MNA). Findings: Sensitivity was equal to 91.1% (95% CI: 78.8-97.5) and 90% (95% CI: 76.4-96.4) for ELISA Coronapass and ELISA Vector-Best respectively. It was equal to 63.1% (95% CI (50.2-74.7) for CMIA Abbott. Specificity was equal to 100% for all the tests. Comparison of ROCs for three tests has shown lower AUC for CMIA Abbott, but not for ELISA Coronapass and CMIA Abbott. The cutoff SC/O ratio of 0.28 for CMIA-Abbott resulted in a sensitivity of 80% at the same full level of specificity. In less than one-third of the population-based study participants with positive antibody test results, we detected neutralizing antibodies in titers 1:80 and above. There was a moderate correlation between antibody assays results and MNA. Interpretation: Our validation study encourages the use of local antibody tests for population-based SARS-CoV-2 surveillance and sets the reference for the seroprevalence correction. Available tests are sensitive enough to detect antibodies in most individuals with previous positive PCR tests with a follow-up of more than 5 months. The Abbott Architect SARS-CoV-2 IgG's sensitivity can be significantly improved by incorporating a new cut-off. Relying on manufacturers' test characteristics for correction of reported prevalence estimates may introduce bias to the study results.

scholarly journals Seroprevalence and correlates of SARS-CoV-2 neutralizing antibodies from a population-based study in Bonn, Germany

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
N. Ahmad Aziz ◽  
Victor M. Corman ◽  
Antje K. C. Echterhoff ◽  
Marcel A. Müller ◽  
Anja Richter ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Response Rate ◽  
Neutralization Test ◽  
Population Based ◽  
Immunofluorescence Assay ◽  
Test Results ◽  
Community Based ◽  
Population Based Study ◽  
Temporal Course ◽  
Confirmatory Tests

AbstractTo estimate the seroprevalence and temporal course of SARS-CoV-2 neutralizing antibodies, we embedded a multi-tiered seroprevalence survey within an ongoing community-based cohort study in Bonn, Germany. We first assessed anti-SARS-CoV-2 immunoglobulin G levels with an immunoassay, followed by confirmatory testing of borderline and positive test results with a recombinant spike-based immunofluorescence assay and a plaque reduction neutralization test (PRNT). Those with a borderline or positive immunoassay result were retested after 4 to 5 months. At baseline, 4771 persons participated (88% response rate). Between April 24th and June 30th, 2020, seroprevalence was 0.97% (95% CI: 0.72−1.30) by immunoassay and 0.36% (95% CI: 0.21−0.61) when considering only those with two additional positive confirmatory tests. Importantly, about 20% of PRNT+ individuals lost their neutralizing antibodies within five months. Here, we show that neutralizing antibodies are detectable in only one third of those with a positive immunoassay result, and wane relatively quickly.

Force of infection of dengue serotypes in a population-based study in the northeast of Brazil

2012 ◽  
Vol 141 (5) ◽  
pp. 1080-1088 ◽  
Author(s):  
P. M. S. CASTANHA ◽  
M. T. CORDEIRO ◽  
C. M. T. MARTELLI ◽  
W. V. SOUZA ◽  
E. T. A. MARQUES ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Dengue Infection ◽  
Population Based ◽  
Northeastern Brazil ◽  
Population Based Study ◽  
Force Of Infection ◽  
Virus Serotype ◽  
Serotype 1 ◽  
Frequent Infection ◽  
Dengue Virus Serotype 1

SUMMARYThis study investigated anti-dengue serotype-specific neutralizing antibodies in a random sample of dengue IgG-positive individuals identified in a survey performed in a hyperendemic setting in northeastern Brazil in 2005. Of 323 individuals, 174 (53·8%) had antibodies to dengue virus serotype 1 (DENV-1), 104 (32·2%) to DENV-2 and 301 (93·2%) to DENV-3. Monotypic infections by DENV-3 were the most frequent infection (35·6%). Of 109 individuals aged <15 years, 61·5% presented multitypic infections. The force of infection estimated by a catalytic model was 0·9%, 0·4% and 2·5% person-years for DENV-1, DENV-2 and DENV-3, respectively. By the age of 5 years, about 70%, 30% and 40% of participants were immune to DENV-3, DENV-2 and DENV-1, respectively. The data suggest that infection with DENV-1, -2 and -3 is intense at early ages, demonstrating the need for research efforts to investigate dengue infection in representative population samples of Brazilian children during early infancy.

scholarly journals AUTOEVALUACIÓN Y AUTOCALIFICACIÓN EN EL GRADO EN CIENCIAS DE LA ACTIVIDAD FÍSICA Y DEL DEPORTE: ESTUDIO CENSAL DE LAS GUÍAS DOCENTES

2018 ◽  
Vol 22 (3) ◽  
Author(s):  
Juan Fraile ◽  
Rodrigo Pardo ◽  
Ernesto Panadero
Keyword(s):  
Communities Of Practice ◽  
Teaching And Learning ◽  
Bologna Process ◽  
Population Based ◽  
Self Assessment ◽  
Population Based Study ◽  
Sport Science ◽  
Sports Science ◽  
Study Results ◽  
Reported Data

Resumen:El Proceso de Bolonia concibe la evaluación como parte del proceso de enseñanza-aprendizaje, denominándose ‘evaluación formativa’, pudiendo ser la autoevaluación una parte esencial del mismo. Esta se entiende como dos acciones: metodología de enseñanza-aprendizaje; o autocalificación, evaluándose cuantitativamente con repercusión en la nota final. Se analizaron 1.761 guías docentes de las asignaturas de 40 universidades españolas que imparten presencialmente el Grado en Ciencias de la Actividad Física y del Deporte, siendo un estudio con el 100 % de la población. Los resultados mostraron que el 7,55 % de las asignaturas emplea la autoevaluación como metodología de enseñanza-aprendizaje; el 9,43 % como autocalificación y el 1,65 % emplea ambas; encontrando diferencias significativas en función de la titularidad, la universidad, la comunidad autónoma y el número de créditos. Estos resultados son muy inferiores comparados con un estudio con datos autorreportados por docentes (Panadero, Brown, y Courtney, 2014), declarando el 89,7 % emplear la autoevaluación y el 66,2 % la autocalificación. Esta investigación constituye su relevancia al aportar una completa visión sobre la implementación de la autoevaluación y la autocalificación en el grado de Ciencias de la Actividad Física y del Deporte en España. Abstract:The Bologna Process understands assessment as a part of the teaching and learning process. It is so-called formative assessment, being self-assessment an essential part of it. Self-assessment can be conceived having two potential actions. First, as a teaching and learning method, being its purpose to teach students how to assess their own work. Second, as self-grading, in order to grade their own achievement with direct impact in their final mark of the course. This study aims to explore the use of self-assessment and self-grading processes in the Degree in Sport Science. 1,761 teaching guides from the syllabus of the 40 Spanish university faculties with attendance studies were analyzed. Thus, this is a population-based study. Results showed that self-assessment is presumably used in 14.99% of subjects: 7.55% with formative purposes, 9.43% as self-grading and 1.65% employ both. Significant differences were found for ownership, university, region and number of credits. Increased use in some regions and universities shows the territorial influence and the existence of teachers´ communities of practice. These results are far lower compared both to another similar research based on self-reported data collected by surveys (Panadero, Brown, & Courtney, 2014), in which 89.7% of teachers reported they use self-assessment and 66.2% self-grading. Therefore, this research is relevant to provide a suitable overview of the implementation of self-assessment and self-grading in the Degree in Sports Science.

scholarly journals New approach to drug therapy of asthma patients at Samara region

2005 ◽  
pp. 108-113
Author(s):  
O. V. Mishchenko ◽  
V. V. Pavlov ◽  
V. I. Kupaev
Keyword(s):  
Drug Therapy ◽  
Healthcare Quality ◽  
Population Based ◽  
Population Based Study ◽  
Healthcare Resources ◽  
New Approach ◽  
Study Results ◽  
Asthma Patients ◽  
Drug Provision

The aim of the study was to analyze granted drug provision for asthma (BA) patients at Samara region to spend healthcare resources more rationally and to improve asthma patients' quality of life. This population-based study of drug therapy involved 19,697 BA patients surveyed at Samara region in 2003–2004. The analysis was performed using a personified database of the granted drug provision and integral parameters of health. We used multi-factorial statistical analysis with mathematical modelling. The results demonstrated that the healthcare quality for BA patients depends on a structure of the drug therapy. A model of basic anti-asthmatic therapy for Samara region was created using the study results.

Sleep Monitoring In A Population-Based Study - Results Of The Study Of Health In Pomerania (SHIP)

2012 ◽  
Author(s):  
Beate Koch ◽  
Thomas Penzel ◽  
Ingo Fietze ◽  
Carmen Garcia ◽  
Sandra Zimmermann ◽  
...  
Keyword(s):  
Population Based ◽  
Sleep Monitoring ◽  
Population Based Study ◽  
Study Results

scholarly journals Performance Evaluation of the Siemens SARS-CoV-2 Total Antibody and IgG Antibody Test

2021 ◽  
Author(s):  
Lisa Florin ◽  
Karel Maelegheer ◽  
Wouter Vandewal ◽  
Dirk Bernard ◽  
Johan Robbrecht
Keyword(s):  
Antibody Test ◽  
Control Group ◽  
Igg Antibody ◽  
Antibody Assays ◽  
Antibody Titers ◽  
Polymerase Chain ◽  
Kinetics Of ◽  
Antibody Tests ◽  
Positive Controls

Abstract Objective In this study, the performance of 2 commercially available SARS-CoV-2 antibody assays is evaluated. Methods The Siemens SARS-CoV-2 Total (COV2T) and IgG (COV2G) antibody tests were evaluated on a Siemens Atellica IM1300 analyzer. Imprecision was assessed with the CLSI EP15 protocol using positive controls. Ninety control group specimens were analyzed for specificity, and 175 specimens from 58 patients with polymerase chain reaction–confirmed SARS-CoV-2 were measured for the sensitivity and kinetics of the antibody response. Results Within-run and total imprecision were acceptable for both assays. Both tests showed a specificity of 100%. Sensitivity earlier in the disease state was greater for the COV2T assay than for the COV2G assay, but sensitivity &gt;14 days after onset of symptoms approached 100% for both. For all patients, antibody titers remained above the seroconversion cutoff for all follow-up specimens. Conclusion This study shows acceptable performance for both the Siemens COV2T and COV2G test, although seroconversion occurs earlier with the COV2T test.

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