Epidemiology of respiratory syncytial virus in young, hospitalized children in Jordan: a prospective viral surveillance study.

Respiratory syncytial virus (RSV) is a leading cause of hospitalization in young children. Understanding RSV burden and seasonality is crucial for implementing effective preventive strategies, especially in the wake of disruptions related to the coronavirus disease 2019 (COVID-19) pandemic. We aimed to determine RSV burden and seasonality among young children hospitalized in Jordan. We conducted a prospective viral surveillance study at Al-Bashir Hospital (1 November 2023 to 4 April 2024). Children <5 years old hospitalized with fever or respiratory symptoms were eligible. Nasal (and optional throat) swabs were collected and tested for common respiratory viruses using real-time polymerase chain reaction. We compared characteristics and outcomes of hospitalizations by RSV detection status and assessed RSV seasonality. Of 2,610 children, RSV was detected in 713 (27.3%), making it the second most common virus overall and the most common in children <2 years old (n = 680 [30.0%]). Children with RSV were more likely than those without RSV to receive low-flow oxygen (74.9% vs 23.2%; P < 0.001) and high-flow nasal cannulation (3.2% vs 1.2%; P < 0.001) and were more likely to be admitted to the intensive care unit (13.2% vs 8.2%; P < 0.001). At least one other respiratory virus was co-detected with RSV in 244 children (34.2%). During the 2023-2024 season, RSV circulation exhibited a clear winter seasonality, consistent with historical patterns. In conclusion, the burden of RSV in children in Jordan remains substantial following the COVID-19 pandemic. The return to historical winter seasonality has important implications for the timing of preventive interventions. Continued surveillance is crucial for monitoring RSV epidemiology in this region. IMPORTANCE: This study confirms the persistent and significant burden of respiratory syncytial virus (RSV) among young, hospitalized children in Jordan. Crucially, our data reveal the normalization of RSV circulation patterns in 2024 following disruptions related to the coronavirus disease 2019 pandemic. This finding has important implications for optimizing the timing of preventive interventions, such as monoclonal antibodies and maternal vaccination, particularly in a resource-limited setting where they are costly and limited in availability. By providing these contemporary surveillance data from the Eastern Mediterranean-where sentinel surveillance platforms are lacking-this work has the potential to inform public health strategies directly and emphasizes the critical need for sustained monitoring to guide effective RSV prevention and control efforts.