Paediatric admissions with SARS-CoV-2 during the Delta and Omicron waves: an Australian single-centre retrospective study

Abstract

Background The clinical course of Australian children admitted to hospital with COVID-19 infection is not well understood, particularly over the Omicron period.Methods This study describes paediatric admissions to a single tertiary paediatric institution through the Delta and Omicron variant waves. All children admitted from 1 June 2021 to 30 September 2022 with a diagnosis of COVID-19 infection were included for analysis.Results 117 patients were admitted during the Delta wave compared with 737 during the Omicron wave. The median length of stay was 3.3 days (IQR 1.7–6.75.1) during Delta, compared with 2.1 days (IQR 1.1–3.4) during Omicron (p<0.01). 83 patients (9.7%) required intensive care unit (ICU) admission, a greater proportion during Delta (20, 17.1%) than Omicron (63, 8.6%, p<0.01). Patients admitted to the ICU were less likely to have received a dose of COVID-19 vaccination prior to admission than patients admitted to the ward (8, 24.2% vs 154, 45.8%, p=0.028).Conclusion The Omicron wave resulted in an absolute increase in the number of children compared with Delta, but cases had lower severity, demonstrated by shorter length of stay and a smaller proportion of patients requiring intensive care. This is consistent with US and UK data describing a similar pattern.