Respiratory syncytial virus (RSV) is a leading cause of severe respiratory illness in adults aged 60 years and older globally. Risk of severe disease increases with advancing age and the presence of comorbidities, especially cardiopulmonary conditions and diabetes. In older adults, RSV is often underrecognized because presenting symptoms can be non-specific and diagnostic testing is limited. In Brazil, RSV has been identified as a contributor to hospitalizations and deaths among older adults, but comprehensive, nationwide epidemiological descriptions have been limited. This study uses the national Influenza Epidemiological Surveillance Information System - Gripe to characterize RSV-associated severe acute respiratory infection (SARI) hospitalizations among adults aged ≥60 years from 2013 through 2024.
The analysis was retrospective and based on surveillance data reported to the Gripe system. The study population comprised adults aged 60 years or older with RSV-associated SARI hospitalizations recorded between 2013 and 2024. Key outcomes extracted from the surveillance database included the number and frequency of hospitalizations, in-hospital mortality, case fatality rates (CFRs), seasonality, healthcare resource utilization (including length of stay and intensive care use), and the prevalence of comorbidities among reported cases. Temporal comparisons were made between pre-pandemic and post-pandemic periods, with post-pandemic defined to include 2020–2024.
Between 2013 and 2024, surveillance records included 4,636 RSV-related hospitalizations among adults aged ≥60 years in Brazil. Hospitalization rates increased markedly over the study period—from less than 1 per 100,000 population in 2013 to more than 15 per 100,000 in 2024—with a pronounced rise after the COVID-19 pandemic (2020–2024).
Female patients represented the majority of reported hospitalizations (59%). Geographically, hospitalizations were concentrated in the South and Southeast regions of Brazil; the authors note this concentration was at least partly attributable to regional differences in test availability and reporting.
In-hospital mortality rose over time. The mean in-hospital mortality was reported as nearly fivefold higher in the post-pandemic period compared with pre-pandemic years. Overall case fatality rates remained high, ranging from 21% to 31% across the reporting years, with the highest CFRs observed in adults aged ≥80 years.
Healthcare resource utilization was substantial. The mean length of hospital stay among cases was 12.9 days. Nearly one-third of cases required admission to an intensive care unit (ICU), and among those admitted to ICU more than two-thirds required ventilatory support.
Comorbidities were common: 71% of hospitalized cases had at least one comorbidity. The most frequently recorded conditions were cardiovascular disease (65%) and diabetes (33%). These comorbidities were strongly associated with increased mortality and greater healthcare resource use in the surveillance data.
Seasonality and testing patterns were described in relation to surveillance reporting, with the post-pandemic period showing increased case detection; specifics of seasonal peaks or month-by-month patterns were reported in the original article but are summarized here as an overall post-pandemic increase in hospitalizations.
The national surveillance analysis demonstrates that RSV imposes a substantial and increasing burden among Brazilian adults aged ≥60 years. Key findings include a marked rise in hospitalization rates after the COVID-19 pandemic, persistently high case fatality rates (21–31%), prolonged hospital stays (mean 12.9 days), and intensive healthcare resource utilization including frequent ICU admission and ventilatory support. Comorbid cardiovascular disease and diabetes were highly prevalent and associated with worse outcomes.
These results highlight gaps in detection and the potential underestimation of RSV disease burden among older adults. The authors emphasize the need to strengthen RSV surveillance in Brazil and to consider discussions around vaccination strategies for older adults in order to mitigate severe outcomes and resource strain.
The authors reported multiple industry affiliations and potential competing interests. Several authors are employees of or hold equities in a vaccine manufacturer; other authors are employees of an epidemiologic consultancy. Additional author disclosures include grants, contracts, honoraria, advisory board participation, and consultancy relationships with various vaccine and pharmaceutical companies, listed in the original publication. The authors declared no patents, products in development, or marketed products associated with this research.
The study is indexed under MeSH terms including Aged; Aged, 80 and over; Brazil / epidemiology; Databases, Factual; Female; Hospital Mortality; Hospitalization / statistics & numerical data; Humans; Male; Middle Aged; and Respiratory Syncytial Virus Infections / epidemiology.