Invasive pneumococcal disease in the Netherlands: Syndromes, outcome and potential vaccine benefits

With a retrospective study of invasive pneumococcal disease (IPD) surveillance data representative for ∼25% of the Dutch population (1275 hospitalized cases) over the period June 2004–June 2006 prior to the implementation of the 7-valent pneumococcal conjugate vaccine (PCV7), the aim was to provide baseline data on IPD for the interpretation of changes after implementation of conjugate vaccines. The IPD incidence peaked in 3–5-mnth-olds (63 cases per 100,000 persons yearly) and increased in adulthood, particularly after the age of 60 yrs, from 26 cases in 60–64-yr-olds to 97 cases per 100,000 in persons ≥90 yrs. Beyond the age of 4 yrs, 19% of IPD patients were immunocompromised, and this considerable percentage may have implications for vaccine efficacy.