Feasibility and Effectiveness Assessment of SARS-CoV-2 Antigenic Tests in Mass Screening of a Pediatric Population and Correlation with the Kinetics of Viral Loads.

The gold standard for diagnosis of SARS-CoV-2 infection has been nucleic acid amplification tests (NAAT). However, rapid antigen detection kits (Ag-RDTs), may offer advantages over NAAT in mass screening, generating results in minutes, both as laboratory-based test or point-of-care (POC) use for clinicians, at a lower cost. We assessed two different POC Ag-RDTs in mass screening versus NAAT for SARS-CoV-2 in a cohort of pediatric patients admitted to the Pediatric Emergency Unit of IRCCS-Polyclinic of Sant'Orsola, Bologna (from November 2020 to April 2021). All patients were screened with nasopharyngeal swabs for the detection of SARS-CoV-2-RNA and for antigen tests. Results were obtained from 1146 patients. The COVID-19 Ag FIA kit showed a baseline sensitivity of 53.8% (CI 35.4-71.4%), baseline specificity 99.7% (CI 98.4-100%) and overall accuracy of 80% (95% CI 0.68-0.91); the AFIAS COVID-19 Ag kit, baseline sensitivity of 86.4% (CI 75.0-93.9%), baseline specificity 98.3% (CI 97.1-99.1%) and overall accuracy of 95.3% (95% CI 0.92-0.99). In both tests, some samples showed very low viral load and negative Ag-RDT. This disagreement may reflect the positive inability of Ag-RDTs of detecting antigen in late phase of infection. Among all cases with positive molecular test and negative antigen test, none showed viral loads > 106 copies/mL. Finally, we found one false Ag-RDTs negative result (low cycle thresholds; 9 × 105 copies/mL). Our results suggest that both Ag-RDTs showed good performances in detection of high viral load samples, making it a feasible and effective tool for mass screening in actively infected children.

Gender differences in weight gain during lockdown due to COVID-19 pandemic in adolescents with obesity.

BACKGROUND AND AIM: Lockdown due to COVID-19 pandemic has forced a decrease in physical activity (PA), an increase in sedentary behavior (SB) and a possibly worsening of fat accumulation in already obese subjects. The aim of this study was to investigate how social restriction may have contributed to weight changes in adolescents with obesity. Secondary aim was to evaluate possible parameters influencing weight changes. METHODS AND RESULTS: Parameters of 51 obese adolescents were compared between two visits: within 2 months before 8 March, start of lockdown, and within 40 days after the end of it. RESULTS: Mean weight gain during lockdown was 2.8 ± 3.7 kg (p < 0.001). Weight increase was higher in males than in females (3.8 ± 3.4 kg vs 1.2 ± 3.7 kg, p = 0.02). The hours dedicated to SB increased (+2.9 ± 2.8 h/day; p < 0.001) while the hours of PA decreased (-1.0 ± 1.6 h/week; p < 0.001). Males spent more hours in SB than females (+3.8 ± 2.7 h/day vs +1.5 ± 2.5 h/day; p = 0.003). There were minor changes in diet during lockdown. The most significant variables influencing both delta BMI and waist/height ratio increase were hours devoted to SB during lockdown and differences in mild and moderate PA before and after lockdown. CONCLUSIONS: Obese adolescents showed a worsening of obesity during lockdown, with males mainly affected, mainly due to a reduced mild PA and increased hours spent in SB.

COVID-19 and the re-opening of schools: a policy maker's dilemma.

The epidemic of coronavirus disease 2019 (COVID-19) broke out in Wuhan, China, in December 2019 and rapidly spread across the world. In order to counter this epidemic, several countries put in place different restrictive measures, such as the school's closure and a total lockdown. However, as the knowledge on the disease progresses, clinical evidence showed that children mainly have asymptomatic or mild disease and it has been suggested that they are also less likely to spread the virus. Moreover, the lockdown and the school closure could have negative consequences on children, affecting their social life, their education and their mental health. As many countries have already entered or are planning a phase of gradual lifting of the containment measures of social distancing, it seems plausible that the re-opening of nursery schools and primary schools could be considered a policy to be implemented at an early stage of recovery efforts, putting in place measures to do it safely, such as the maintenance of social distance, the reorganisation of classes into smaller groups, the provision of adequate sanitization of spaces, furniture and toys, the prompt identification of cases in the school environment and their tracing. Therefore, policy makers have the task of balancing pros and cons of the school re-opening strategy, taking into account psychological, educational and social consequences for children and their families. Another issue to be considered is represented by socio-economic disparities and inequalities which could be amplified by school's closure.