Respiratory Syncytial Virus hospitalization burden: a nation-wide population-based analysis, 2000-2017.

Objectives: Respiratory Syncytial Virus (RSV) is a known cause of morbidity among young children, while RSV-related disease in the elderly is not fully recognized. Several RSV candidate vaccines for infants, pregnant women and adults are under development. We aimed to estimate nationwide age-specific hospitalizations and seasonal trends, to help determine the optimal age for vaccination.

Methods: Hospitalizations with a primary RSV-related diagnoses were retrieved from the National Hospital Database for the years 2000-2017. Data were analyzed by year, month and age group to determine hospitalization rates and seasonal trends.

Results: During the analysis period, 39,156 hospitalizations received primary RSV-related ICD-9 diagnostic codes. The highest mean yearly hospitalization rate occurred among infants <1 year of life (1,218.4 per 100,000). Within the first year of life, the highest mean yearly hospitalization rate was observed in the second month of life (3,541.5 hospitalizations per 100,000). Hospitalization rates for individuals ≥5 years old increased during the study period, primarily among patients ≥65 years of age, reaching hospitalization rate of 9 per 100,000 in 2017. A clear seasonal pattern was observed.

Conclusions: An effective vaccine for infants and pregnant women has the potential to reduce hospitalizations burden. RSV-related hospitalizations burden among adults requires additional research.