Laboratory surveillance of Streptococcus pneumoniae from invasive disease, Chile 2007-2012

Background: 10-valent pneumococcal vaccine (PCV-10) was introduced in 2011 to the National Immunization Program in Chile. It was administered in 4 doses, but in 2012 it was modified to a 3 dose program. This article shows the results of the Laboratory Surveillance System for Streptococcus pneumoniae isolated of invasive disease from 2007 to 2012 and compares the incidence of invasive pneumococcal disease (IPD) by age groups in the prevaccinal (2007-2010) and postvaccinal period (2012). Methods: Descriptive study of S. pneumoniae surveillance in invasive diseases cases confirmed at the National Reference Laboratory of the Institute of Public Health of Chile from 2007 to 2012. Results: Global incidence of laboratory confirmed IPD cases decreased 27.8% from 2007 to 2012 and showed a lower risk for IPD in 2012 compared with 2007. Incidence in children aged 1 year or less decreased from 56.1 to 16.3 per 100,000 and from 42.0 to 19.9 per 100,000 in children aged 12 to 23 months in the same period. Highest decreases were observed in IPD cases caused by serotypes 4 (100%), 19F (93.3%), 23F (90.9%), 14 (81.1%), 6B (70%), 18C (58.3%) and 1(81.8%) in children aged 2 years or less. Conclusion: Surveillance System detects S. pneumoniae isolated from invasive diseases, contributing with information about laboratory confirmed IPD trends, prevalent serotypes and replacement effects. These results can be used as evidence in healthcare decision making for pneumococcal vaccines.