Corona Immunitas: study protocol of a nationwide program of SARS-CoV-2 seroprevalence and seroepidemiologic studies in Switzerland

West, Erin; Anker, Daniela; Amati, Rebecca; Richard, Aude; Wisniak, Ania; Butty, Audrey; Albanese, Emiliano; Bochud, Murielle; Chioléro, Arnaud; Crivelli, Luca; Cullati, Stéphane; D’Acremont, Valérie; Epure, Adina Mihaela; Fehr, Jan; Flahault, Antoine; Fornerod, Luc; Frank, Irène; Frei, Anja; Michel, Gisela; Gonseth, Semira; Guessous, Idris; Imboden, Medea; Kahlert, Christian; Kaufmann, Marco; Köhler, Philipp; Mösli, Nicolai; Paris, Daniel; Probst‐Hensch, Nicole; Rodondi, Nicolas; Stringhini, Silvia; Vermes, Thomas; Vollrath, Fabian; Puhan, Milo A.

doi:10.1007/s00038-020-01494-0

Cited by 89 publications

(118 citation statements)

References 17 publications

Supporting

Mentioning

117

Contrasting

Order By: Relevance

“…The protocol for this longitudinal cohort study is reported elsewhere 4 . The study is part of a large nationally coordinated research network Corona Immunitas in Switzerland 5,6 . A random sample of schools, stratified by district, and randomly selected classes in lower school level (grades 1-2, attended by 6 to 9-year-old children), middle (grades 4-5, 9 to 13-year-old children), and upper school level (grades 7-8, 12 to 16-year-old children), ensuring that the same cohort of children within the class can be followed until April 2021.…”

Section: Methodsmentioning

confidence: 99%

Variation in SARS-CoV-2 seroprevalence in school-children across districts, schools and classes

Ulytė

Radtke

Abela

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Importance: Understanding transmission and impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in school children is critical to implement appropriate mitigation measures. Objective: To determine the variation in SARS-CoV-2 seroprevalence in school children across districts, schools, grades, and classes, and the relationship of SARS-CoV-2 seroprevalence with self-reported symptoms. Design: Cross-sectional analysis of baseline measurements of a longitudinal cohort study (Ciao Corona) from June-July 2020. Setting: 55 randomly selected schools and classes stratified by district in the canton of Zurich, Switzerland (1.5 million inhabitants). Participants: Children, aged 6-16 years old, attending grades 1-2, 4-5 and 7-8. Exposure: Exposure to circulating SARS-CoV-2 between February and June 2020 including public lock-down and school closure (March 16-May 10, 2020). Main Outcomes and Measures: Variation in seroprevalence of SARS-CoV-2 in children across 12 cantonal districts, schools, and grades using a Luminex-based antibody test with four targets for each of IgG, IgA and IgM. Clustering of cases within classes. Analysis of associations of seropositivity and symptoms. Comparison of seroprevalence with a randomly selected adult population, based on Luminex-based IgG and IgA antibody test of Corona Immunitas. Results: In total, 55 schools and 2585 children were recruited (1337 girls, median age 11, age range 6-16 years). Overall seroprevalence was 2.8 % (95% CI 1.6-4.1%), ranging from 1.0% to 4.5% across districts. Seroprevalence was 3.8% (1.9-6.1%) in grades 1-2, 2.5% (1.1-4.2%) in grades 4-5, and 1.5% (0.5-3.0%) in grades 7-8. At least one case was present in 36/55 tested schools and in 43/128 classes with ≥50% participation rate and ≥5 children tested. 73% of children reported COVID-19 compatible symptoms since January 2020, but none were reported more frequently in seropositive compared to seronegative children. Seroprevalence of children was very similar to seroprevalence of randomly selected adults in the same region in June-July 2020, measured with the same Corona Immunitas test, combining IgG and IgA (3.1%, 95% CI 1.4-5.4%, versus 3.3%, 95% CI 1.4-5.5%). Conclusions and Relevance: Seroprevalence was inversely related to age and revealed a dark figure of around 90 when compared to 0.03% confirmed PCR+ cases in children in the same area by end of June. We did not find clustering of SARS-CoV-2 seropositive cases in schools so far, but the follow-up of this school-based study will shed more light on transmission within and outside schools. Trial registration: ClinicalTrials.gov Identifier: NCT04448717, registered June 26, 2020. https://clinicaltrials.gov/ct2/show/NCT04448717

show abstract

Section: Methodsmentioning

confidence: 99%

Variation in SARS-CoV-2 seroprevalence in school-children across districts, schools and classes

Ulytė

Radtke

Abela

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…We randomly selected classes within participating schools, stratified by school level: lower school level (grades 1 and 2; children aged 6-9 years); middle school level (grades 4 and 5; children aged 9-13 years); and upper school level (grades 7 and 8; children aged 12-16 years). We selected grades to ensure that the same cohorts would be in the classes until April 2021, when further testing is planned (children in grades 3, 6, and 9 often change class and school during the next [18][19][20][21][22]. We aimed to enrol at least three classes and at least 40 children from each school level at the invited schools.…”

Section: Populationmentioning

confidence: 99%

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

Ulytė

Radtke

Abela

et al. 2021

BMJ

Self Cite

100

View full text Add to dashboard Cite

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

show abstract

“…As of January 27, 2021, more than 100 million people were diagnosed with the coronavirus disease 2019 (COVID-19) and over 2 million died due to this infection (1). The majority of infected people are asymptomatic (2, 3) or have mild symptoms such as fever, cough, dyspnea, fatigue, or anosmia/dysgeusia (4, 5). However, severe COVID-19 symptoms can also be life-threatening and require to be hospitalized (6).…”

Section: Introductionmentioning

confidence: 99%

Muscle strength is associated with COVID-19 hospitalization in adults 50 years of age or older

Cheval

Sieber

Maltagliati

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Background. Muscle strength has been associated with a wide range of health outcomes. Yet, whether individuals with weaker strength are more at risk for severe COVID-19 is still unclear. The objective of this study was to investigate the independent association between muscle strength and COVID-19 hospitalization. Methods. Data from 3600 adults 50 years of age and older were analyzed using logistic models adjusted for several chronic conditions, body mass index, age, and sex. Hand grip strength was repeatedly measured between 2004 and 2017 using a handheld dynamometer. COVID-19 hospitalization during the lockdown was self-reported in summer 2020 and was used an indicator of COVID-19 severity. Results. Results showed that higher grip strength was associated with a lower risk of COVID-19 hospitalization (adjusted odds ratio [OR] per increase of 1 SD in grip strength = .64, 95% confidence interval [95% CI] = .45-.87, p = .015). Results also showed that age (OR for a 10-year period = 1.70, 95% CI = 1.32-2.20, p < .001) and obesity (OR = 2.01, 95% CI = 1.00-3.69, p = .025) was associated with higher risk of COVID-19 hospitalization. Sensitivity analyses using different measures of grip strength and robustness analyses based on rare-events logistic regression and COVID-19 patients were consistent with the main results. Conclusions. Muscle strength is an independent risk factor for COVID-19 severity in adults 50 years of age and older.

show abstract

Corona Immunitas: study protocol of a nationwide program of SARS-CoV-2 seroprevalence and seroepidemiologic studies in Switzerland

Cited by 89 publications

References 17 publications

Variation in SARS-CoV-2 seroprevalence in school-children across districts, schools and classes

Variation in SARS-CoV-2 seroprevalence in school-children across districts, schools and classes

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

Muscle strength is associated with COVID-19 hospitalization in adults 50 years of age or older

Contact Info

Product

Resources

About