Clinical and economic burden of respiratory syncytial virus among adults hospitalised with acute respiratory infections in Portugal.

Abstract

Background: Respiratory syncytial virus (RSV) is an important cause of acute respiratory infection (ARI), but its burden in Portuguese adults remains under-investigated.

Methods: This single-centre retrospective database cohort study examined RSV-ARI hospitalisations in adults aged ≥18 years over six consecutive seasons (2018/19 to 2023/24), a period which includes years impacted by COVID-19 disruptions. Outcomes included the prevalence of RT-PCR-confirmed RSV-ARI among tested ARI admissions, clinical features and adverse outcomes, healthcare resource use and direct costs; outcomes were also described for influenza-ARI to provide context. Analyses were descriptive without any comparison between the groups.

Results: Of 7,125 ARI-hospitalisations 3,011 underwent RSV/influenza testing. The overall prevalence of RT-PCR-confirmed RSV-ARI and influenza-ARI in tested admissions was 8.1% and 20.3%, respectively. The study included 244 RSV-ARI and 612 influenza-ARI admissions, most ≥60 years old; 77.1% of RSV-ARI admissions and 61.4% of influenza-ARI admissions involved high-risk patients with comorbidities. Complications within 90 days were frequent, including acute cardiac events (RSV-ARI, 47.1%; influenza-ARI, 38.2%), respiratory failure (46.3% and 31.5%), pneumonia (34.0% and 22.4%) and acute renal disease (34.0% and 29.3%). All-cause in-hospital mortality was 19.7% for RSV-ARI (influenza-ARI, 12.8%). Mean length of stay for RSV-ARI was 8.5 days (interquartile range ([IQR], 9.7) with a mean cost of €4 757; for influenza-ARI, 7.4 days (IQR 8.9) and €3 537, respectively.

Conclusions: RSV represents an important cause of ARI-hospitalisation in older adults, especially in those with comorbidities, with a substantial clinical and economic burden, which was similar or higher than influenza (GSK study identifier: VEO-000773).