Increase in invasive nonvaccine pneumococcal serotypes at two hospitals in Barcelona: was replacement disease to blame?
Article first published online: 17 JUN 2011
© 2011 The Author(s)/Acta Pædiatrica © 2011 Foundation Acta Pædiatrica
Volume 100, Issue 12, pages 1572–1575, December 2011
How to Cite
Pérez, A., Giménez, M., Sala, P., Sierra, M., Esteve, A. and Rodrigo, C. (2011), Increase in invasive nonvaccine pneumococcal serotypes at two hospitals in Barcelona: was replacement disease to blame?. Acta Paediatrica, 100: 1572–1575. doi: 10.1111/j.1651-2227.2011.02365.x
- Issue published online: 8 NOV 2011
- Article first published online: 17 JUN 2011
- Accepted manuscript online: 28 MAY 2011 06:27AM EST
- Received 20 October 2010; accepted 25 May 2011.
- Heptavalent pneumococcal conjugate vaccine;
- Invasive pneumococcal disease;
- Streptococcus pneumoniae
Aim: To describe an increase in the incidence of invasive pneumococcal disease (IPD) caused by serotypes not contained in the heptavalent pneumococcal conjugate vaccine (PCV7) in children in two hospitals in Barcelona with different vaccine uptake.
Methods: Cumulative incidences of IPD, vaccine and nonvaccine serotypes (NVSTs), and main clinical presentations before (1998–2001) and after vaccine introduction (2005–2008) were compared.
Results: The incidence of IPD in children aged <2 years at Hospital Germans Trias i Pujol covering a population in which PCV7 was not widely used showed a nonsignificant increase from 29.9 to 58.8 per 100 000 child-years between both periods. Following vaccine introduction, there was a 2.5-fold increase in IPD caused by NVSTs in children aged <5 years. Analysis of trends in the almost fully vaccinated population of Hospital de Barcelona revealed a nonsignificant reduction in IPD incidence in children aged <2 years from 63.1 to 26.0 per 100 000 child-years. NVSTs in children aged <5 years showed a nonsignificant 1.7-fold increase in the vaccine period at this centre.
Conclusions: The paradoxical increase in invasive infections caused by NVSTs in these populations with different vaccine use suggests that these changes were not driven only by PCV7.