Streptococcus pneumoniae serotype 1 causing invasive disease among children in Barcelona over a 20-year period (1989-2008).

Fifty-six isolates of serotype 1 were identified during a 20-year prospective study (1989-2008), including all children with culture-proven invasive pneumococcal disease (IPD) admitted to a children's hospital in Barcelona. Forty-eight of them (85.7%) were in children aged >2 years. Complicated pneumonia (n = 28) and non-complicated pneumonia (n = 20) were the main clinical presentations. The frequency of serotype 1 IPD increased from 1999-2003 to 2004-2008: 1.2 to 4.4 episodes/100 000 children (p <0.001). The ST306 clone were identified in 70.4% of isolates. As IPD caused by serotype 1 is mainly detected in older children, a vaccination programme for children >2 years should be considered.