Respiratory syncytial virus-associated hospitalisation in adults with comorbidities in two European countries

BackgroundIndividuals with comorbidities are at increased risk of severe RSV infection. We estimated RSV-associated respiratory tract infection (RTI) hospitalisation among adults aged 45 years and older with comorbidities in Denmark and Scotland. MethodsBy analysing national hospital and virological data, we estimated annual average number and rate of RSV-associated hospitalisations by seven selected comorbidities and age during 2010-2018. We estimated rate ratios (RRs) of RSV-associated hospitalisation and 95% uncertainty ranges in comorbid adults versus the overall populations. ResultsIn Danish adults aged 45y+, RSV-RTI hospitalisation rates ranged from 3.1 per 1000 individuals with asthma, to 19.4 per 1000 individuals per year with chronic kidney disease (CKD). In Scotland, the rate ranged from 2.4 per 1000 individuals per year with chronic liver disease (CLD), to 9.0 per 1000 individuals per year with chronic obstructive pulmonary disease (COPD). In both countries, we found over 2-4-fold increased risk of RSV hospitalisation in adults with COPD, ischemic heart disease (IHD), stroke and diabetes, and 1.5-3-fold increased risk for adults with asthma and 3-7-fold for those with CKD. RSV hospitalisation rates among adults aged 45-64y with COPD, asthma, IHD or CKD were higher compared with the overall population aged 65-74y. ConclusionFindings of this study provide important evidence for identifying risk groups and assisting health authorities in RSV vaccination policy making.