Estimation of the number of RSV-associated hospitalisations in adults in the European Union

Background: Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections in older adults that can result in hospitalisations and death. Estimating RSV-associated hospitalisation is critical for planning RSV-related healthcare needs for the ageing population across Europe. Methods: We gathered national RSV-associated hospitalisation estimates from the REspiratory Syncytial virus Consortium in EUrope (RESCEU) for adults in Denmark, England, Finland, Norway, Netherlands, and Scotland from 2006 to 2017. We extrapolated these estimates to 28 EU countries using nearest-neighbour matching, multiple imputations, and two sets of 10 indicators. Results: On average, 158 229 (95%CI: 140 865, 175 592) RSV-associated hospitalisations occur annually among adults in the EU (above 18 years); 92% of these hospitalisations occur in adults over 65 years. Among 75-84 years old, the annual average is estimated at 74 519 (95%CI: 69 923, 79 115) at a rate of 2.24 (95%CI: 2.10, 2.38) per 1000 adults. Among adults aged 85 years and above, the annual average is estimated at 37 904 (95%CI: 32 444, 43 363) at a rate of 2.99 (95%CI: 2.56, 3.42). Conclusion: Our estimates of RSV-associated hospitalisations in older adults are the first analysis integrating available data to provide estimates of the disease burden in this population across the EU. Importantly, for a condition which was considered in the past to be primarily a disease of young children, the average annual hospitalisation estimate in adults was lower but of a similar magnitude to the estimate in young children aged 0-4 years: 158 229 (95%CI: 140 865, 175 592) versus 245 244 (95%CI: 224 688, 265 799).