ABSTRACT
Objective(s): To describe the severity and clinical spectrum of SARS-CoV-2 infection in Australian children during the 2021 Delta outbreak. Design, Setting & Participants: A prospective cohort study of children <16 years with a positive SARS-CoV-2 nucleic acid test cared for by the Sydney Children's Hospital Network (SCHN) virtual and inpatient medical teams between 1 June-31 October 2021. Main outcome measures: Demographic and clinical data from all admitted patients and a random sample of outpatients managed under the SCHN virtual care team were analysed to identify risk factors for admission to hospital. Results: There were 17,474 SARS-CoV-2 infections in children <16 years in NSW during the study period, of whom 11,985 (68.6%) received care coordinated by SCHN. Twenty one percent of children infected with SARS-CoV-2 were asymptomatic. For every 100 SARS-CoV-2 infections in children <16 years, 1.26 (95% CI 1.06 to 1.46) required hospital admission for medical care; while 2.46 (95% CI 2.18 to 2.73) required admission for social reasons only. Risk factors for hospitalisation for medical care included age <6 months, a history of prematurity, age 12 to <16 years, and a history of medical comorbidities (aOR 7.23 [95% CI 2.92 to 19.4]). Of 17,474 infections, 15 children (median age 12.8years) required ICU admission; and 294 children required hospital admission due to social or welfare reasons. Conclusion: The majority of children with SARS-CoV-2 infection (Delta variant) had asymptomatic or mild disease. Hospitalisation was uncommon and occurred most frequently in young infants and adolescents with comorbidities. More children were hospitalised for social reasons than for medical care.