Viral Landscape, Clinical Impact, and Management Trends in Hospitalized Children for Viral-Associated Lower Respiratory Tract Diseases: A Comparative Analysis of Two Post-Pandemic Seasons in Rome, Italy.

After the COVID-19 emergency, respiratory viruses have re-emerged with changing and region-specific patterns. We aimed to characterize how these shifts affected viral circulation, clinical severity, and management of pediatric viral-associated lower respiratory tract disease (LRTD)across two post-pandemic seasons in Rome, Italy. We conducted a retrospective observational study of children (< 6 years) hospitalized with PCR-confirmed viral LRTDs during the 2022-2023 and 2023-2024 seasons. Of the 1,249 children hospitalized for LRTD, 49.08% were admitted during the 2022-2023 season and 50.92% during the 2023-2024 season. Clinical severity at presentation (PRESS ≥ 4) did not differ between the two seasons; however, a severe in-hospital course (CSS > 3) was more frequent in 2023-2024 (8.96% vs. 4.24%; p = 0.001). In 2023-2024, the corticosteroid use increased (77.20% vs. 72.43%; p = 0.05), whereas antibiotic use decreased (47.80% vs. 39.78%; p = 0.004). Respiratory syncytial virus remained the most common pathogen in both seasons, with no significant variation between them. Similarly, influenza showed no significant difference in prevalence. Compared with 2022-2023, 2023-2024 showed a higher prevalence of rhinovirus (50.31% vs. 37.36%), enterovirus (24.53% vs. 15.82%), bocavirus (13.99% vs. 8.16%) and viral codetection (51.89% vs. 45.02%) while adenovirus was more frequent in 2022-2023 (7.39% vs. 13.21%). Multivariable analysis identified the 2023-2024 season (OR 2.37; 95% CI 1.45-3.87), younger age (OR 0.96 per month; 95% CI 0.94-0.98), and comorbidities (OR 2.91; 95% CI 1.66-5.11) as independent predictors of severe in-hospital course. Male sex, viral codetection, and viral clinical categories were not associated with severity. In conclusion, in Rome's regional context, the evolving viral ecology highlights the need for continued local surveillance to guide clinical preparedness and optimize management in forthcoming seasons.