Hospital-based surveillance of respiratory syncytial virus in Central Queensland.

Abstract

Background: Respiratory syncytial virus (RSV) is a leading cause of acute lower respiratory tract infections, especially in infants and young children globally. Despite its impact, RSV testing and epidemiological data remain limited, particularly in regional Australia. Central Queensland, with its subtropical climate, provides a unique setting in which to study RSV trends, testing patterns, and associated hospital burden.

Methods: This study used hospital-based data to analyse RSV-related hospitalisations and testing from Central Queensland. Data were collected retrospectively between 2018 and 2021 and prospectively between 2022 and 2023. Eligible cases included individuals presenting to or admitted at any hospitals in Central Queensland with laboratory-confirmed RSV or RSV-related diagnoses based on ICD-10-AM codes. The analysis focused on RSV-related hospital admissions and hospitalisation outcomes. Incidence rate ratios (IRR) for hospitalisation rates between the two periods were calculated.

Results: Between 2018 and 2023, there were 1,279 RSV-related hospitalisations, with 53.2% of cases being male. Infants under 12 months accounted for the highest proportion of admissions (38.4%). RSV-related hospitalisations peaked during the prospective study period, rising from 123 in 2018 to 357 in 2023. The hospitalisation rate among infants was significantly higher in the prospective study period compared to the retrospective study period (IRR: 2.2; 95% confidence interval [95% CI]: 1.8-2.6; p < 0.001). The Indigenous population had a significantly higher hospitalisation rate than the non-Indigenous population over the whole study period (IRR: 3.1; 95% CI: 2.7-3.6; p < 0.001). The median length of stay was two days, with 20.6% of those hospitalised requiring ventilation, 2.2% needing intensive care unit (ICU) support, and 0.9% of hospitalisations resulting in death. Mortality was highest among those aged 60 years and above (91.7%). Although infants under 12 months had the lowest RSV testing rates (9.8%), they had the highest test positivity rate (16.4%).

Conclusions: RSV admissions have been under-reported due to limited testing. Increased awareness and widespread testing during prospective surveillance revealed a significant rise in RSV-related admissions. These findings underscore the need for enhanced RSV testing, improved resource allocation, and expanded immunisation efforts to effectively manage the burden of RSV.