Pneumococcal serotype distribution in invasive paediatric disease in Southern Finland before the introduction of vaccine.

Vaccination with pneumococcal conjugate vaccines (PCV) has been started in many countries, resulting in a marked decrease in the incidence of invasive pneumococcal disease (IPD). After the decline, an increase in the incidence of IPD caused by non-vaccine serotypes has been observed. Finland has just decided to incorporate PCV into the national immunization programme, starting 1 September 2010. We describe the patients treated for IPD in one hospital in Finland before the use of PCV. Details of patients treated for IPD at the Children's Hospital, University of Helsinki between 2002 and 2007, were sought using the hospital discharge register and laboratory data. In total 118 cases of IPD were diagnosed in 113 children between 1 January 2002 and 31 December 2007. The yearly number of cases of IPD increased from 10 in 2002 to 26 in 2007. There were 5 deaths, all in patients with meningitis (5/19, 26%), and the total mortality was 4% (5/113). Seventy-five (77%) of the 97 pneumococcal isolates for which serotype was available were covered by the 7-valent PCV; 77% were also in the 10-valent PCV and 91% in the 13-valent PCV. Considering the serotype distribution of the pneumococcal isolates, a marked benefit is expected from including PCV in the vaccination programme.