External quality assurance scheme for Streptococcus pneumoniae 2010 : as part of the IBD-Labnet surveillance network

Streptococcus pneumoniae is the causative agent of a wide spectrum of diseases ranging from upper respiratory tract infections to severe invasive disease. S. pneumoniae is the most frequently isolated respiratory pathogen in community-acquired pneumonia and the most commonly observed infection due to it is otitis media. Invasive pneumococcal disease (IPD), defined as the isolation of S. pneumoniae or detection of S. pneumoniae nucleic acid or antigen from a normally sterile fluid, may feature as meningitis, bacteraemic pneumonia, occult bacteraemia, septic shock and, less frequently, arthritis and peritonitis. Essentially all strains of S. pneumoniae have a polysaccharide capsule, which is the basis for serotyping. Currently, 91 distinct serotypes have been identified. Overall, 20 serotypes account for more than 80% of IPD. Prevention of the invasive pneumococcal disease can be achieved by vaccination. The heptavalent pneumococcal conjugate vaccine (PCV7) targets seven out of these serotypes.