Community-acquired pneumonia (CAP) remains a major global contributor of human morbidity and mortality, with Streptococcus pneumoniae as the leading bacterial cause across all ages. While pneumococcal vaccines reduce the impact of pneumococcal disease, the burden remains high, in both invasive and non-invasive disease, partly due to infection with pneumococcal serotypes not included in currently available vaccines. CAP also leads to significant healthcare costs, a burden likely to grow with ageing populations. To inform vaccine development and public health policies regarding vaccination, additional data are needed to understand the morbidity and mortality associated with specific pneumococcal serotypes, and the effectiveness of currently available vaccines. This paper describes the design and rationale of the Pneumococcal Pneumonia Epidemiology, Urine Serotyping and Mental Outcomes (PNEUMO) study Europe. This multicentre, prospective, population-based, active surveillance observational study will enrol approximately 9000 adult patients hospitalised with all-cause CAP at 50 academic hospital sites across six countries in Europe, focusing on pneumococcal disease and non-pneumonia invasive pneumococcal disease. The primary goal is to estimate the incidence of pneumococcal pneumonia and serotype prevalence among adults in Europe. The study will also track in-hospital outcomes and, in a subset of approximately 600 patients, follow-up assessing the trajectory of functional and cognitive outcomes over six months. Besides the typing of isolates when available, serotype-specific urinary antigen detection assays will be used to identify serotypes from both invasive and non-invasive disease.
