Comparative Analysis of Pediatric Hospitalizations during Two Consecutive Influenza and Respiratory Virus Seasons Post-Pandemic

Background: The COVID-19 pandemic has had a significant impact on the epidemiology of respiratory viruses. Non-pharmaceutical interventions (NPIs) led to a dramatic reduction in respiratory infections. However, the long-term effects on respiratory virus epidemiology remain unclear. Materials and Methods: We conducted a comparative study on hospitalized pediatric patients with respiratory illness during two seasons: 1 October 2021 to 15 March 2022 and 1 October 2022 to 15 March 2023. We compared the type of virus, mean duration of hospitalization, and disease severity. Results: In the first season, 47.1% of patients (65/138) tested positive for at least one respiratory virus, with respiratory syncytial virus (RSV) being the most frequent (23.2%). In the second season, 82.9% of patients (102/123) tested positive, with RSV and Rhinovirus being the most prevalent (28.38% and 27.03%, respectively). Other viruses, such as Influenza A/B, Metapneumovirus, and Adenovirus, also showed increased prevalence. Disease severity and mean duration of hospitalization were similar between the two seasons. Conclusions: Our study highlights increased prevalence in respiratory viruses, including RSV and Rhinovirus, following the easing of NPIs. The prevalence in respiratory viruses, including RSV and Rhinovirus, increased in the second season compared to the first one. Interestingly, RSV's peak incidence shifted from February to November. The emergence of rhinovirus as the most prevalent respiratory virus during certain months suggests viral competition and dynamic changes in viral circulation. The overall severity of respiratory infections remained relatively stable between the seasons.