Temporal and geographic stability of the serogroup-specific invasive disease potential of Streptococcus pneumoniae in children

A meta-analysis study design was used to analyze 7 data sets of invasive and carriage pneumococcal isolates recovered from children, to determine whether invasive disease potential differs for each serotype and, if so, whether it has changed over time or differs geographically. Serotype- and serogroup-specific odds ratios (ORs) were calculated for each study and as a pooled estimate, with use of serotype 14 as the reference group. ORs varied widely: the serotypes with the highest ORs (1, 5, and 7) were 60-fold more invasive than those with the lowest ORs (3, 6A, and 15). There was a significant inverse correlation between invasive disease and carriage prevalence for the serotypes that we considered, which implies that the most invasive serotypes and serogroups were the least commonly carried and that the most frequently carried were the least likely to cause invasive disease. There was no evidence of any temporal change or major geographical differences in serotype- or serogroup-specific invasive disease potential.