Overview of Invasive Streptococcus Pneumoniae Infection in Taiwan, 2008-2010

This article analyzes the general situation of 2,233 cases of invasive Streptococcus pneumoniae infection and 2,141 isolated strains nationally and locally in Taiwan from January of 2008 to December of 2010. The majority of cases are situated in northern Taiwan with 27% of the national numbers, followed by middle Taiwan with 21%. The main epidemic season of Streptococcus pneumoniae infection each year starts from December and lasts until March of the following year, whereas the period between June and September has the lowest incident rate. As of March, 2010, the number of infections in Taiwan has shown increase, especially in northern Taiwan, and among children below 5 years of age. The yearly incident rate in each region is approximately 3 cases in every 100,000 persons, mainly infecting subjects below 5 years of age and above 65 years of age with a total of more than 10 cases per 100,000 persons each year. By analyzing the serotypes of these isolated strains, it is found that the serotype 19A strain cases has mostly increased among children in the northern region and has become the main epidemic serotype of strain in the nation as of 2010; therefore, influencing the protection effectiveness of the currently used 7-Valent Pneumococcal Conjugate Vaccine (PCV7). As of 2010, the coverage rate of PCV7 among children under 5 years of age in northern Taiwan and Taoyuan, Hsinchu, and Miaoli areas has dropped to less than 35%. The change in the serotype of the strain caused the drop in the vaccine coverage rate, has also greatly impacted the infection of invasive Streptococcus pneumoniae. Thus, the continuous monitoring of this isolated strain can provide immediate and effective epidemic data for preventive strategy reference.