To evaluate the potential impact of various pneumococcal conjugate vaccination strategies, it is critical to ascertain the pre-vaccination epidemiology and to have a detailed evaluation of the current burden of pneumococcal disease.

A variety of national data sources and GP sentinel surveillance systems were used to estimate the incidence, number of hospital admissions, deaths, and GP consultations due to pneumococcal disease in England and Wales. Clinical outcomes included pneumococcal meningitis, bacteraemia, pneumonia and otitis media. A statistical model was used to attribute GP consultation recorded as pneumonia and acute otitis media to specific aetiological causes when these were not recorded.

The burden of pneumococcal disease is considerable, with incidence rates of both invasive and non-invasive disease peaking in children (<5 years) and in the elderly (75+ years). Around 5800 hospitalisations specifically mentioning Streptococcus pneumoniae are estimated to occur annually in England and Wales, almost 40000 for lobar pneumonia and over 15000 for otitis media. There may be an additional 70000 GP consultations for pneumococcal related community acquire pneumonia and over 630000 for otitis media. A significant proportion of hospitalisations and GP consultations for pneumococcal disease occur among high-risk groups, with over 80% of hospital admissions reporting more than one diagnosis.