Epidemiology, clinical course and complications of RSV infection in older adults in the outpatient sector in Germany

<bold>Background:</bold> Acute respiratory infections (ARI) caused by respiratory syncytial virus (RSV) impose a significant burden on healthcare systems and particularly affect adults aged 60 years and older. The epidemiology, importance and severity of RSV infections in this population in the outpatient setting are poorly defined. <bold>Methods:</bold> BUCOSS is a multi-seasonal, active observational study including patients aged 60+ years presenting with ARI from 29 primary care and pulmonology practices. The study aims to describe the burden of disease, clinical course and complications after RSV infection over a period of 28 days. <bold>Results:</bold> 1436 patients with ARI were included over the first two seasons with confirmed RSV infection in 98 (7%) cases. On average RSV prevalence was higher in patients aged 70-79 and 80-89 years than in those aged 60-69 years and in patients with lower respiratory tract infections compared to those with upper respiratory tract infections. During infection season, RSV prevalence was highest in January. RSV infection differs from other viral respiratory infections by proportionally more frequent occurrence of purulent sputum and rales with a mean symptom duration of 19 days. 28 days after infection, 22% of patients still suffered from respiratory symptoms. Fifty percent of patients had an underlying pulmonary disease, mainly asthma or COPD (n=48) which worsened in 23 cases (48%). Two cases required hospitalization within 28 days. <bold>Conclusion:</bold> RSV accounts for a significant proportion of infections in adults aged 60+ in the outpatient setting and is associated with relevant symptoms, duration and severity of illness, particularly in patients with chronic lung disease.