Burden of respiratory syncytial virus (RSV) hospitalizations among adults aged 60 years or more in Brazil: A retrospective surveillance database analysis (2013-2024).

BACKGROUND: Globally, respiratory syncytial virus (RSV) is a leading cause of severe respiratory illness in adults aged ≥60 years. Risk increases with advancing age and comorbidities, particularly cardiopulmonary disease and diabetes. RSV disease burden in adults is often underestimated due to non-specific presentation and limited testing. In Brazil, RSV is a recognized driver of hospitalizations and deaths in older adults, yet comprehensive epidemiological data remain scarce. Here, we describe RSV-associated severe acute respiratory infection (SARI) hospitalizations among adults aged ≥60 years in Brazil between 2013 and 2024. METHODS: We retrospectively analyzed RSV-associated SARI hospitalizations reported to the national Influenza Epidemiological Surveillance Information System -Gripe. Outcomes included hospitalization frequency, in-hospital mortality, case fatality rates (CFRs), seasonality, healthcare resource utilization, and comorbidities. RESULTS: Between 2013 and 2024, 4,636 RSV-related hospitalizations occurred in adults aged ≥60 years, increasing sharply after the COVID-19 pandemic (2020-2024). Hospitalization rates increased from <1 per 100,000 in 2013 to >15 per 100,000 in 2024. Women accounted for most cases (59%), and hospitalizations were concentrated in the South and Southeast regions partly due to test availability. In-hospital mortality increased over time, with mean rates nearly fivefold higher post-pandemic than pre-pandemic. CFRs remained consistently high (21-31%), particularly in adults aged ≥80 years. The mean length of hospital stay was 12.9 days. Almost one-third of cases required intensive care unit admission, of whom more than two-thirds needed ventilatory support. Comorbidities were present in 71% of cases, most commonly cardiovascular (65%) and diabetes (33%)were strongly associated with increased mortality and healthcare resource utilization. CONCLUSIONS: RSV poses a substantial and increasing burden among Brazilian adults aged ≥60 years, with a high CFR, prolonged hospitalizations, and intensive healthcare resource utilization. These findings highlight the need to strengthen RSV surveillance and discuss vaccination strategies for adults aged older in Brazil.