Monitoring the impact of Respiratory Syncytial Virus (RSV) in Spain’s Autonomous Communities: Time-series models in public health
RSV surveillance is essential because of its impact in young children and older adults. Since 2023/24, passive immunization with nirsevimab has been recommended for infants under 6 months at the start of the RSV season or born during it and for high-risk older children.
Weekly time series of severe RSV hospitalization incidence per 100000 inhabitants are analyzed from 2022/23 to 2025/26 in 5 Spanish Autonomous Communities, covering over 55% of the population. 8 age groups are considered, focusing on <1, 1-4 and >60 years.
We use Dynamic Factor Models to compare forecasting strategies: modelling all age groups within each region versus jointly modelling each age group across regions. Preliminary results show high synchrony across regions in <1-year incidence, with one common factor explaining over 99% of the variability, supporting joint multiregional forecasting. More accurate predictions may help in decision making about healthcare planning and resource management during RSV seasons.
Keywords: Forecasting Multivariate Time Series Dimensionality reduction SDG Respiratory infection