Unveiling the Spectrum of Respiratory Syncytial Virus Disease in Adults: From Community to Hospital

Background: Respiratory syncytial virus can cause severe disease in the older adult population. Three vaccines for RSV are currently market approved but the risk of RSV-hospitalization in (older) adults from a community level remains elusive. We aimed to estimate the risk of RSV-hospitalization and characterize the patients that end up in hospital. Methods: We manually analyzed records of adults aged ≥ 20 with RSV-infection between 2022 and 2024 in three hospitals in the Netherlands. These hospitals implemented routine RSV-testing at emergency departments. Using population-based data in combination with the in-hospital data, we estimated the population risk of RSV-hospitalization. Hospital records were analyzed to characterize the role RSV played in their course of disease. Results: We analyzed 709 RSV cases of whom 503 (70.9%) were hospitalized. Five hundred twenty-six patients were ≥ 60, and 183 were < 60 years of age. The population RSV-hospitalization rate was 6–20 per 100.000 patients aged 20–59 years and 43–236 per 100.000 for those ≥ 60. The highest risks were observed in those with COPD (1702 per 100.000) and with congestive heart disease (2383 per 100.000). RSV caused clinically relevant infection in 88% of hospitalized cases but was only mentioned using specific ICD-codes in 4.4%. Comorbidity was prevalent (88.5%) and exacerbation of underlying disease caused of 46.3% of RSV-related hospital admissions. ICU admittance was 11.2% and in-hospital mortality was 8.1%. Conclusion: The risk of RSV-hospitalization from the community is low but is increased substantially in those with underlying disease. RSV is often clinically relevant in hospitalized patients by causing exacerbation of underlying disease but is infrequently mentioned in specific ICD-codes.