Sixty strains of S. pneumoniae isolated from the patients with upper respiratory tract infections were immunologically classified by use of Danish type/group specific antisera. The percentages of S. pneumoniae serologically defined were 23. 3% for Group 23, 20. 0% for Group 19, 13. 3% for Group 6, 10. 0% for Type 3, 3. 3% for Type 4, 3. 3% each for Type 9 and 18, and 1. 6% for Type 14. It was confirmed that in case of acute otitis media Group 19 and Type 3 were characteristic showing 30. 0% and 13.4%, while rhinosinusitis were highly related to Group 23 of S. pneumoniae. An additional analyses revealed that Type 3 of S. pneumoniae were mostly found in the patients over 50 years old, though the patients under 5 years old were related to Group 19.
