Distribution of vaccine serotypes among Streptococcus pneumoniae colonizing the upper respiratory tract in healthy pre-school children in south-east Poland.

Aim: Studies on the distribution of Streptococcus pneumoniae serotypes associated with colonization of the upper respiratory tract in young children are currently of general interest because of the impact of the new pneumococcal conjugate vaccines (PCV) on carriage of pneumococci and the incidence of pneumococcal disease.

Material And Methods: Therefore, we evaluated the coverage of 10-valent PCV (PCV10) as well as 13-valent PCV(PCV13) of S. pneumoniae serotypes isolated from the upper respiratory tract in healthy pre-school children in south-east Poland.

Results: Among the 342 pneumococcal isolates, the serotype coverage by PCV-10 or PCV-13 was 73.7% or 80.1%, respectively. Moreover, 92.4% of the isolates belonged to serotypes included in the "old" 23-valent polysaccharide vaccine. A clear picture of the distribution of S. pneumoniae serotypes associated with colonization and/or infection in various geographical areas is needed in a light of recommended or routine vaccination.