scholarly journals Clustering and longitudinal change in SARS-CoV-2 seroprevalence in school-children: prospective cohort study of 55 schools in Switzerland

2020 ◽  
Author(s):  
Agne Ulyte ◽  
Thomas Radtke ◽  
Irene A. Abela ◽  
Sarah R. Haile ◽  
Christoph Berger ◽  
...  
Keyword(s):  
Cohort Study ◽  
Prospective Cohort Study ◽  
School Children ◽  
Prospective Cohort ◽  
Participation Rate ◽  
School Level ◽  
Longitudinal Change ◽  
High Exposure ◽  
Link Type ◽  
June July

AbstractBackground and aimsThe facilitating role of schools in SARS-CoV-2 infection spread is still debated and the potential of school closures to mitigate transmission unclear. In autumn 2020, Switzerland experienced one of the highest second waves of the SARS-CoV-2 pandemic in Europe while keeping schools open, thus offering a high-exposure environment to study SARS-CoV-2 infections in schools. The aim of this study was to examine longitudinal change in SARS-CoV-2 seroprevalence in children and the evolution of clustering within classes and schools from June to November, 2020, in a prospective cohort study of school children in the canton of Zurich, Switzerland.MethodsChildren from randomly selected schools and classes, stratified by district, were invited to participate in serological testing of SARS-CoV-2 in June-July and October-November 2020. Parents of children filled questionnaires on sociodemographic and health-related questions. 55 schools and 275 classes within them were enrolled, with 2603 children participating in the first, and 2552 in the second testing (age range 6-16 years). We evaluated longitudinal changes of seroprevalence in districts and investigated clustering of seropositive cases within classes and schools.ResultsOverall SARS-CoV-2 seroprevalence was 2.4% (95% CrI 1.4%-3.6%) in summer and 4.5% (95% CrI 3.2%-6.0%) in not previously seropositive children in late autumn, leading to estimated 7.8% (95% CrI 6.2%-9.5%) of ever seropositive children, without significant differences among lower, middle and upper school levels. Among the 2223 children with serology tested twice, 28 (40%) of previously seropositive were negative, and 109 (5%) previously negative became seropositive. Seroprevalence was not different between school levels or sexes, but varied across districts (1.7% to 15.0%). Between June-July and October-November 2020, the ratio of diagnosed to newly seropositive children was 1 to 8. At least one newly seropositive child was detected in 47 of 55 schools and 90 of 275 classes. Among 130 classes with high participation rate, 0, 1-2 or ≥3 seropositive children were present in 73 (56%), 50 (38%) and 7 (5%) classes, respectively. Class level explained slightly more variation of individual serological results (standard deviation of random effects (SD) 0.97) than school level (SD 0.61) in the multilevel logistic regression models. Symptoms were reported for 22% of seronegative and 29% of newly seropositive children since summer.ConclusionsUnder a regimen of open schools with some preventive measures in place since August, clustering of seropositive cases occurred in very few classes and not across entire schools despite a clear increase in seropositive children during a period of high transmission of SARS-CoV-2.Trial registrationClinicalTrials.gov NCT04448717. https://clinicaltrials.gov/ct2/show/NCT04448717

scholarly journals Clustering and longitudinal change in SARS-CoV-2 seroprevalence in school children in the canton of Zurich, Switzerland: prospective cohort study of 55 schools

BMJ ◽  
2021 ◽  
pp. n616
Author(s):  
Agne Ulyte ◽  
Thomas Radtke ◽  
Irene A Abela ◽  
Sarah R Haile ◽  
Christoph Berger ◽  
...  
Keyword(s):  
Cohort Study ◽  
Prospective Cohort Study ◽  
Prospective Cohort ◽  
Participation Rate ◽  
Credible Interval ◽  
School Level ◽  
Longitudinal Change ◽  
High Exposure ◽  
Logistic Regression Models ◽  
June July

Abstract Objectives To examine longitudinal changes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence and to determine the clustering of children who were seropositive within school classes in the canton of Zurich, Switzerland from June to November 2020. Design Prospective cohort study. Setting Switzerland had one of the highest second waves of the SARS-CoV-2 pandemic in Europe in autumn 2020. Keeping schools open provided a moderate to high exposure environment to study SARS-CoV-2 infections. Children from randomly selected schools and classes, stratified by district, were invited for serological testing of SARS-CoV-2. Parents completed questionnaires on sociodemographic and health related questions. Participants 275 classes in 55 schools; 2603 children participated in June-July 2020 and 2552 in October-November 2020 (age range 6-16 years). Main outcome measures Serology of SARS-CoV-2 in June-July and October-November 2020, clustering of children who were seropositive within classes, and symptoms in children. Results In June-July, 74 of 2496 children with serological results were seropositive; in October-November, the number had increased to 173 of 2503. Overall SARS-CoV-2 seroprevalence was 2.4% (95% credible interval 1.4% to 3.6%) in the summer and 4.5% (3.2% to 6.0%) in late autumn in children who were not previously seropositive, leading to an estimated 7.8% (6.2% to 9.5%) of children who were ever seropositive. Seroprevalence varied across districts (in the autumn, 1.7-15.0%). No significant differences were found among lower, middle, and upper school levels (children aged 6-9 years, 9-13 years, and 12-16 years, respectively). Among the 2223 children who had serology tests at both testing rounds, 28/70 (40%) who were previously seropositive became seronegative, and 109/2153 (5%) who were previously seronegative became seropositive. Symptoms were reported for 22% of children who were seronegative and 29% of children who were newly seropositive since the summer. Between July and November 2020, the ratio of children diagnosed with SARS-CoV-2 infection to those who were seropositive was 1 to 8. At least one child who was newly seropositive was detected in 47 of 55 schools and in 90 of 275 classes. Among 130 classes with a high participation rate, no children who were seropositive were found in 73 (56%) classes, one or two children were seropositive in 50 (38%) classes, and at least three children were seropositive in 7 (5%) classes. Class level explained 24% and school level 8% of variance in seropositivity in the multilevel logistic regression models. Conclusions With schools open since August 2020 and some preventive measures in place, clustering of children who were seropositive occurred in only a few classes despite an increase in overall seroprevalence during a period of moderate to high transmission of SARS-CoV-2 in the community. Uncertainty remains as to whether these findings will change with the new variants of SARS-CoV-2 and dynamic levels of community transmission. Trial registration NCT04448717

scholarly journals Evolution of SARS-CoV-2 seroprevalence and clusters in school children from June 2020 to April 2021 reflect community transmission: prospective cohort study Ciao Corona

2021 ◽  
Author(s):  
Agne Ulyte ◽  
Thomas Radtke ◽  
Irene A Abela ◽  
Sarah R Haile ◽  
Priska Ammann ◽  
...  
Keyword(s):  
Middle School ◽  
Cohort Study ◽  
Prospective Cohort Study ◽  
Prospective Cohort ◽  
Participation Rate ◽  
School Level ◽  
June July ◽  
Age Range ◽  
Second Wave ◽  
Middle School Level

Objectives: To longitudinally assess severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence and clustering of seropositive children within school classes in March-April 2021 compared to June-July and October-November 2020. To examine the evolution of symptoms and the extent of under-detection of SARS-CoV-2 in children. Design: Prospective cohort study of randomly selected schools and classes. Setting: Schools remained open for physical attendance in Switzerland from May 2020 to the end of 2020/2021 school year. Lower school level (age range 7-10 years) and middle school level (8-13 years) children in primary schools, and upper school level (12-17 years) children in secondary schools were invited for SARS-CoV-2 serological testing in the Ciao Corona study in the canton of Zurich, Switzerland. Three testing rounds were completed in June-July 2020 (T1; after the first wave of SARS-CoV-2 infections), October-November 2020 (T2; during the peak of the second wave), and March-April 2021 (T3; after the second wave and with SARS-CoV-2 variants of concern becoming dominant). Parents completed questionnaires on sociodemographic information and symptoms. Participants: 2487 children (median age 12 years, age range 7-17 years) recruited from 275 classes in 55 schools participated in the testing in March-April 2021; total of 2974 children participated in at least one of the 3 testing rounds. Main outcome measures: SARS-CoV-2 serology results; clustering of seropositive children within classes; reported symptoms. Results: The proportion of children who were SARS-CoV-2 seropositive increased from 1.5% (95% credible interval (CrI) 0.6% to 2.6%) in June-July 2020, to 6.6% (95% CrI 4.0% to 8.9%) in October-November, and to 16.4% (95% CrI 12.1% to 19.5%) in March-April 2021. By March-April 2021, children in upper school level (12.4%; 95% CrI 7.3% to 16.7%) were less likely to be seropositive than those in middle (19.5%; 95% CrI 14.2% to 24.4%) or lower school levels (16.0%; 95% CrI 11.0% to 20.4%). Children in the upper school level had a 5.1% (95% CI -9.4% to -0.7%) lower than expected seroprevalence by March-April 2021 than those in middle school level, based on difference-in-differences analysis. The ratio of PCR-diagnosed to all seropositive children changed from 1 to 21.7 (by June-July 2020) to 1 to 3.5 (by March-April 2021). Symptoms were reported by 37% of newly seropositive and 16% seronegative children. Potential clusters of 3 or more newly seropositive children were detected in 24 of 119 (20%) classes with a high participation rate, from which a median of 17 clusters could be expected due to random distribution of seropositive children within the classes. Clustering was lowest in middle and upper school levels. Retention rate in the cohort was high (84% of T1 participants attended T3). Among participants, supporting society and research were reported more commonly for participation than personal reasons. Fear of blood sampling was the most frequently reported reason for non-participation, reported for 64% of children. Conclusions: By March-April 2021, 16.4% of children and adolescents were seropositive in the canton of Zurich, Switzerland. The majority of clusters of SARS-CoV-2 seropositive children in school classes could be explained by community rather than intra-class transmission of infections. Seroprevalence and clustering was lowest in upper school levels during all timepoints. Trial registration: ClinicalTrials.gov NCT04448717. Key words: SARS-CoV-2, COVID-19, children, adolescents, school, SARS-CoV-2 symptoms, non-participation, participation rate, cohort.

scholarly journals Evaluation of the mechanisms of sarcopenia in chronic inflammatory disease: protocol for a prospective cohort study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amritpal Dhaliwal ◽  
Felicity R. Williams ◽  
Jonathan I. Quinlan ◽  
Sophie L. Allen ◽  
Carolyn Greig ◽  
...  
Keyword(s):  
Cohort Study ◽  
Prospective Cohort Study ◽  
Inflammatory Disease ◽  
Prospective Cohort ◽  
Inflammatory Diseases ◽  
Chronic Inflammatory Disease ◽  
Assessment Model ◽  
Chronic Inflammatory Diseases ◽  
Link Type ◽  
Disease Specific

Abstract Background Several chronic inflammatory diseases co-exist with and accelerate sarcopenia (reduction in muscle strength, function and mass) and negatively impact on both morbidity and mortality. There is currently limited research on the extent of sarcopenia in such conditions, how to accurately assess it and whether there are generic or disease-specific mechanisms driving sarcopenia. Therefore, this study aims to identify potential mechanisms driving sarcopenia within chronic inflammatory disease via a multi-modal approach; in an attempt to help define potential interventions for future use. Methods This prospective cohort study will consist of a multi-modal assessment of sarcopenia and its underlying mechanisms. Recruitment will target three chronic inflammatory diseases: chronic liver disease (CLD) (n=50), with a subset of NAFLD (n=20), inflammatory bowel disease (IBD) (n=50) and rheumatoid arthritis (RA) (n=50) both before and after therapeutic intervention. In addition, 20 age and sex matched healthy individuals will be recruited for comparison. Participants will undergo 4 assessment visits at weeks 0, 2, 12 and 24. Visits will consist of the following assessments: blood tests, anthropometrics, functional assessment, quadriceps muscle imaging, actigraphy, quality of life questionnaires, food diary collection and muscle biopsy of the vastus lateralis (at weeks 2 and 24 only). In addition, stool and urine samples will be collected for future microbiome and metabolomics analysis. Discussion This is the first study to use a multi-modal assessment model to phenotype sarcopenia in these chronic inflammatory diseases. We hope to identify generic as well as disease-specific mechanisms driving sarcopenia. We appreciate that these cohorts do require separate standards of care treatments which limit comparison between groups. Ethics and dissemination The study is approved by the Health Research Authority - West Midlands Solihull Research Ethics Service Committee Authority (REC reference: 18/WM/0167). Recruitment commenced in January 2019 and will continue until July 2021. The study was halted in March 2020 and again in January 2021 with the COVID-19 pandemic. The findings will be disseminated through peer-reviewed publications and conference presentations. All data will be stored on a secure server. Trial registration ClinicalTrials.gov Identifier: NCT04734496

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