Objectives To study the incidence of invasive pneumococcal disease (IPD) presenting to a tertiary level paediatric intensive care unit (PICU) before and after the introduction of routine vaccination in the UK.
Methods Retrospective and prospective case note study recording all children admitted to the intensive care unit with IPD. Correlation of all cases identified with the PICAnet database. Serotypes were identified whenever possible and vaccination status recorded for children admitted after September 2006.
Results There was a rise in the numbers of IPD cases admitted each year from 1992 to 2006, which has not declined post-vaccination introduction. Serotyping done in 14/38 cases identified from 2003 to 2006; 2/14 of these serotypes are not included in the 7-valent conjugate vaccine. Serotyping done in 8/15 cases identified from 2006 to 2007 post-vaccine introduction; 3/8 serotypes would have been covered by the 7-valent vaccine but the children had not been vaccinated; 5/8 of these serotypes identified are not found in the vaccine and three of these children had been vaccinated.
Conclusion The reasons for the rising incidence of IPD from 1996 to 2006 are unclear. The introduction of routine vaccination with the conjugate 7-valent vaccine has yet to make an impact on the incidence presenting to PICU. This may be partly due to the slow uptake of vaccination (following recent vaccination health scares) or it may be due to a rise in disease caused by the serotypes not included in the vaccination.