Factors associated with hospital and intensive care admission in paediatric SARS-CoV-2 infection: a prospective nationwide observational cohort study
Authors: Uka Anita , Buettcher Michael , Bernhard-Stirnemann Sara , Fougère Yves , Moussaoui Dehlia , Kottanattu Lisa , Wagner Noémie , Zimmermann Petra , Ritz Nicole ,   Swiss Paediatric Surveillance Unit (SPSU), Albisetti M. , Bernet V. , Betti C. , Cachat F. , Caplazi P. , Decker M-L. , Durrer E. , Fluri S. , Gebauer M. , Gehri M. , Giannoni E. , Grupe S. , Horn M. , L’Huiller A. , Karen T. , Kellner E. , Laube G. , Laubscher B. , Llor J. , Luterbacher F. , Madlon H. , Malzacher A. , Martins M. , McDougall J. , Merglen A. , Minocchieri S. , Muehlethaler V. , Neuhaus T. , Niederer A. , Nikorelou S. , Plebani M. , Ratnasabapathy  , Relly C. , Riedel T. , Russo M. , Schmid H. , Staudacher K. , Torres Escobar M. , Wildhaber J. , Wörner A. , Zemmouri A. 
Published: December 2021

Coronavirus disease 2019 (COVID-19) is usually less severe in children compared to adults. This study describes detailed clinical characteristics, treatment and outcomes of children with COVID-19 in a non-hospitalised and hospitalised setting and quantifies factors associated with admission to hospital and intensive care unit in children with SARS-CoV-2 infection on a nationwide level. Data were collected through the Swiss Paediatric Surveillance Unit from children < 18 years with confirmed SARS-CoV-2 infection. All 33 paediatric hospitals in Switzerland reported non-hospitalised and hospitalised cases from March 1 to October 31, 2020 during both pandemic peaks. In total, 678 children were included. The median age was 12.2 years (IQR 5.0–14.6), 316 (46.6%) were female and 106 (15.6%) had comorbidities. Overall, 126 (18.6%) children were hospitalised of whom 16 (12.7%) required ICU admission. Comorbidities were the only factor associated with hospital admission in a multivariable regression analysis (odds ratio 3.23, 95%CI 1.89 to 5.50;p-value < 0.01). Children with preexisting comorbidities did not require ICU admission more often. Hospitalised children more often presented with fever (96 [76.2%] vs 209 [38.1%],p-value < 0.01) and rash (16 [12.8%] vs 6 [1.1%],p-value < 0.01). Anosmia/dysgeusia was more prevalent in non-hospitalised children (73 [13.3%] vs 3 [2.4%],p-value < 0.01). In hospitalised children, oxygen treatment was required in 34 (27.0%), inotropes in nine (7.3%) and mechanical ventilation in eight (6.3%) cases. Complications were reported in 28 (4.1%) children with cardiovascular complications being most frequent (12 [1.8%]). Three deaths were recorded.

Conclusion: This study confirms that COVID-19 is mostly a mild disease in children. Fever, rash and comorbidities are associated with higher admission rates. Continuous observation is necessary to further understand paediatric COVID-19, guide therapy and evaluate the necessity for vaccination in children.What is Known:• Clinical manifestations of SARS-CoV-2 infection in children vary from asymptomatic to critical disease requiring intensive care unit admission.• Most studies are based on hospitalised children only; currently, there is limited data on non-hospitalised children.What is New:• The clinical spectrum and severity of COVID-19 is influenced by age: in children less than 2 years, fever, cough and rhinorrhoea are the most common symptoms and in adolescents, fever, cough and headache are more common.• Hospitalised children more often presented with fever and rash, while anosmia/dysgeusia is more prevalent in non-hospitalised children.• Children with pre-existing comorbidities are more frequently hospitalised but do not require ICU admission more often.