Study of Children Aged Under 2 Years Admitted With RSV at Four Australian Hospitals [2021-2022].

Aims: Primary aim was to review severe acute respiratory infections (SARI) hospitalisations caused by respiratory syncytial virus (RSV) in children aged < 2 years in paediatric hospitals in Australia. Secondary aims included RSV subtyping, assessing RSV seasonality and contributing to the World Health Organisation's RSV surveillance programme.

Methods: We prospectively reviewed the medical records of children (< 2 years of age) with a confirmed SARI who were admitted to one of four major Australian paediatric hospitals and had a respiratory sample analysed by Polymerase Chain Reaction (PCR). A detailed dataset was completed for RSV positive cases.

Results: Between 1 January 2021 and 31 December 2022, 2290 RSV (laboratory-confirmed) admissions were identified (53.4% of all SARI admissions). Approximately 50% of all RSV cases were aged 0-6 months. RSV-A predominated in 2021 with peak infections observed in summer while in 2022 RSV-B predominated with peak infections in the more traditional winter months. The median total length of stay (LOS) for RSV positive admissions was 46 h (IQR: 22-82 h). 9% of these children required an ICU admission with a prolonged median LOS 68 h (IQR: 40-112 h). Respiratory support utilisation was consistent over the 2 years. 1.8% required mechanical ventilation; 4.6% continuous positive airway pressure; 23.3% high flow oxygen; and 50.8% low flow oxygen.

Conclusions: RSV in children continues to cause a significant disease burden at Australian tertiary paediatric centres. Ongoing hospital surveillance is required to document the impact of RSV preventative therapies that have become available in 2024.