Secular change in selected motor performance parameters and BMI in Swiss primary school children from 2014-2021: The Sportcheck+ study.

It is important to monitor secular trends in children's motor performance, as healthy and physically active children are more likely to become healthy and physically active adults. However, studies with regular and standardized monitoring of motor performance in childhood are scarce. Additionally, the impact of COVID-19 mitigation measures on secular trends is unknown. This study describes secular changes in balancing backwards, jumping sidewards, 20-m sprint, 20-m Shuttle Run Test (SRT) and anthropometric data in 10'953 Swiss first graders from 2014 to 2021. Multilevel mixed-effects models were used to estimate secular trends for boys vs. girls, lean vs. overweight and fit vs. unfit children. The potential influence of COVID-19 was also analysed. Balance performance decreased (2.8% per year), whereas we found improvements for jumping (1.3% per year) and BMI (-0.7% per year). 20-m SRT performance increased by 0.6% per year in unfit children. Children affected by COVID-19 measures had an increased BMI and were more overweight and obese, but motor performance was mostly higher. In our sample, secular changes in motor performance show promising tendencies from 2014 to 2021. The effects of COVID-19 mitigation measures on BMI, overweight and obesity should be monitored in additional birth cohorts and follow-up studies.

Accuracy of serological testing for SARS-CoV-2 antibodies: First results of a large mixed-method evaluation study.

BACKGROUND: Serological immunoassays that can identify protective immunity against SARS-CoV-2 are needed to adapt quarantine measures, assess vaccination responses, and evaluate donor plasma. To date, however, the utility of such immunoassays remains unclear. In a mixed-design evaluation study, we compared the diagnostic accuracy of serological immunoassays that are based on various SARS-CoV-2 proteins and assessed the neutralizing activity of antibodies in patient sera. METHODS: Consecutive patients admitted with confirmed SARS-CoV-2 infection were prospectively followed alongside medical staff and biobank samples from winter 2018/2019. An in-house enzyme-linked immunosorbent assay utilizing recombinant receptor-binding domain (RBD) of the SARS-CoV-2 spike protein was developed and compared to three commercially available enzyme-linked immunosorbent assays (ELISAs) targeting the nucleoprotein (N), the S1 domain of the spike protein (S1), and a lateral flow immunoassay (LFI) based on full-length spike protein. Neutralization assays with live SARS-CoV-2 were performed. RESULTS: One thousand four hundred and seventy-seven individuals were included comprising 112 SARS-CoV-2 positives (defined as a positive real-time PCR result; prevalence 7.6%). IgG seroconversion occurred between day 0 and day 21. While the ELISAs showed sensitivities of 88.4% for RBD, 89.3% for S1, and 72.9% for N protein, the specificity was above 94% for all tests. Out of 54 SARS-CoV-2 positive individuals, 96.3% showed full neutralization of live SARS-CoV-2 at serum dilutions ≥ 1:16, while none of the 6 SARS-CoV-2-negative sera revealed neutralizing activity. CONCLUSIONS: ELISAs targeting RBD and S1 protein of SARS-CoV-2 are promising immunoassays which shall be further evaluated in studies verifying diagnostic accuracy and protective immunity against SARS-CoV-2.