Severity of the clinical presentation of hepatitis A in five European countries from 1995 to 2014

Objectives: We analysed Hepatitis A (HepA) notifications and hospitalisations in Italy, Netherlands, Norway, Spain and Sweden for available periods between 1995 and 2014 to investigate whether decreasing HepA incidence is associated with increasing age at infection and worsening HepA presentation, and to identify groups-at-risk of severe disease. Methods: We performed a retrospective cohort study including 36734 notified and 36849 hospitalised patients. We used negative binomial regressions to identify over time i) trends in hospitalisation and notification rates; ii) proportion of hospitalised and notified patients aged ≥40 years; iii) proportion of severe hospitalisations; and iv) risk factors for severe hospitalisation. Results: During the study period: both HepA notifications and hospitalisations decreased, with notification rates decreasing faster; patients aged ≥40 years increased; however, the proportion of severe HepA hospitalisations remained stable. Older patients and patients with co-morbidities, particularly liver diseases, were more likely to experience severe disease. Conclusions: We used digitalised health information to confirm decreasing trends in HepA hospitalisations and notifications, and an increasing age of HepA patients in Europe. We did not identify an increase in the severity of the clinical presentation of HepA patients. Older patients with liver diseases are at increased risk of severe disease and should be prioritised for vaccination.