Distribution of diplococcus pneumoniae types in acute otitis media in children and influence of the types on the clinical course in penicillin V therapy

Pneumococci isolated from the ear exudate in 245 children under 10 years of age afflicted with acute otitis media were typed. Types 3, 6, 14, 18, 19 and 23 were found in 80% of the cases. In the remaining cases, 15 other types were found. Five strains were not typable with the antisera used. Types 14 and 23 were found twice as often in the age group 0-3 years as in the higher age groups, whereas the opposite was true for type 3. The relapse frequency was highest after types 14 and 19 infections. The frequency of residual secretory otitis was highest after type 14 infections. Types 19 and 23 were never found in infections followed by secretory otitis. Patients with type 14 infections, healed or unhealed, showed the same blood group distribution within the ABO and Lewis systems as a normal Swedish population. Penicillin V therapy failed to eliminate the pneumococcal strain from the nasopharynx in 40% of consecutive cases of otitis media. Relapse after penicillin-treated pneumococcal otitis is to be regarded as a new complication of the primary infection and not as a reinfection from the environment.