Safety concerns associated to the clinical picture of Covid-19 in paediatric age: do they oppose or support school closure?
Ever since the early months of the COVID-19 pandemic and up until now, the aggregated data collected from thousands of confirmed paediatric cases of COVID-19 initially in China and then increasingly worldwide points towards reassuring clinical characteristics in <18-year olds. All the published systematic reviews and meta-analyses assessing the disease course in children and adolescents repeatedly reached the conclusion that the clinical picture of COVID-19 appears to be overall significantly milder in paediatric than in adult age, with better prognosis and lower hospitalization rates, as well as low case-fatality ratios (<1% of hospitalized cases)[7,8]. Although symptom prevalence varies among different studies, the majority of confirmed cases the Sars-Cov-2 infection presented with either no or few symptoms, the most commonly reported ones being pyrexia and cough. This appears to be true both for countries that minimized the exposure of children early in the pandemic through school closure, and for those that prioritized keeping children in school throughout the outbreak [9].
More severe clinical pictures requiring hospitalization did occur, reaching a proportion of up to 10 out every 100 cases in the youngest age group (0 to 4-year olds), but most had favourable outcomes [10]. In multivariable analyses of intensive care unit admissions for COVID-19 in paediatric age, the most significant and frequently reported risk factors were age (<1 month), pre-existing medical conditions, and signs or symptoms of lower respiratory tract infection at presentation [11]. In addition, one rare COVID-19 related clinical picture has been defined by the WHO: multisystem inflammatory syndrome in children (MIS-C), characterized by elevated inflammatory markers, constitutional signs of organ dysfunction and evidence of SARS-Cov-2 infection. Furthermore, beyond the acute effects of Sars-Cov-2 infection, there are growing concerns about the so-called “Long-Covid” in children, or rather the presence of long-lasting symptoms ascribed to the infection [12]. From a clinical perspective diagnosing and successfully treating these severe and long-term clinical pictures of COVID-19 in the paediatric age is of utmost importance. However, they neither occur nor lead to unfavourable outcomes frequently enough to be considered a threat to the health of the paediatric population.
One year into the pandemic, through the public health perspective needed for pandemic-related policymaking, the claim that COVID-19 in school-aged children is mostly a mild disease remains undoubtedly evidence-based. Consequently, school closure at times of high background prevalence of COVID-19 should not be considered a measure implemented to protect the health of children.