[Population-based incidence of hospitalised pneumococcal pneumonia in adults with distinct baseline risk strata in Catalonia throughout 2015, the EPIVAC study.]

objectivePneumococcal pneumonia is a major public health problem, especially in high risk population and older adults. This study assessed the epidemiology of pneumococcal pneumonia requiring hospitalisation among adults in Catalonia.

methodsThis is a population-based cohort study, including all individual ≥50 years-old assigned to the Institut Catala de la Salut (Catalonia, Spain), who were prospectively followed from 01/01/2015 to 31/12/2015. The Catalonian information system for the development of research in primary care (SIDIAP) was used to establish baseline characteristics and risk-strata of cohort members at study start: low-risk (immunocompetent persons without risk conditions), intermediate-risk (immunocompetent persons with at-risk condition) and high-risk (immunocompromising conditions). All hospitalisations from pneumococcal pneumonia occurred among cohort members within 2015 were collected from CMBD discharge data of 64 reference Catalonian hospitals.

resultsAmong the 2.025.730 cohort members the global incidence of hospitalised pneumococcal pneumonia was 82.8 cases per 100,000 population-year (9.8 for bacteremic and 72.9 for non- bacteremic cases). Incidence substantially increased by age (34.9 in 50-64 years vs 88.7 in 65-79 years vs 231.5 in >80 years; p<0.001) and baseline-risk stratum (30.1, 119.1 and 240.7 in low-, intermediate- and high-risk stratum, respectively; p<0.001). Overall case-fatality was 4.9% (7.7% in bacteremic vs 4.5% in non- bacteremic; p=0.059). In multivariable models, high-risk stratum and oldest age were the strongest predictors for invasive and non-invasive cases, respectively.

conclusionsThe burden of pneumococcal pneumonia among adults is intermediate-low in Catalonia, but large incidences emerge among oldest persons and immunocompromised subjects.