Ms Jane Tomlinson1, Mrs. Kareena Bhardwaj1, Dr Vanessa Clifford1, Miss Treena Pearson1, Miss Lana McCartney1, Mrs. Alisa Hawley1, Dr Lai-Yang Lee1, Dr Natalie Yap1, Dr Yara-Natalie Abo1, Gregory Waller1, Associate Professor Andrew J Daley1
1The Royal Childrens Hospital, Melbourne, Australia
Biography:
Jane joined the RCH Infection Prevention and Control Team in 2016 and has worked in paediatrics in Australia since 1994. She has a background paediatric infectious diseases, general paediatric and cardiac nursing and in Neonatal Intensive Care. Her interests include healthcare cleaning, equipment and staff health.
Abstract:
Background
Seasonal patterns of respiratory viruses have been identified in southern temperate climates, with changes to the seasonality of the common respiratory viruses noted during and after the COVID-19 pandemic.
Method
Local laboratory data from our hospital is analysed, trended and reported to clinicians and hospital staff monthly – noting seasonality, differing viral patterns and predictions of activity. Respiratory samples are collected from inpatients and unwell children in the Emergency Department. Reports are shared internally across nursing, support services, medical teams, researchers and with the hospital executive.
Results
Risk reduction strategies and non-pharmacological interventions implemented during the pandemic 2020-2022 reduced seasonal viruses. Trends of hospital acquired infection remained steady. Changes in seasonal patterns differed for individual viruses; RSV peaked early and out of season in 2021, followed by a significant surge in winter 2022, before returning to more typical levels, although with an earlier season in 2023 with peak rates in May. Influenza levels remained suppressed until April 2022, followed by higher rates in 2023 and 2024 compared to pre-pandemic seasons; human metapneumovirus and parainfluenza viruses (1 to 4) similarly re-emerged from April 2022.
Conclusion (Implications/Learning)
Our results indicate seasonal patterns, changes to seasonality during the pandemic, and eventual return to pre-pandemic seasonal patterns for some viruses. The RSV season did not return to pre-pandemic patterns, with an earlier seasonal peak, which has affected timing of nirsevimab implementation in Victoria (April to October 2025). Being aware of seasonal viral patterns assists healthcare system planning and resource allocation.