Frequency of Typable and Non-Typable Haemophilus Influenzae Strains in Children with Acute Otitis Media and Results of Penicillin V Treatment

Of 185 Haemophilus influenzae strains from children with acute otitis media, 28 (15.1%) were typable. The overall frequency of therapeutic failure with penicillin V therapy at a daily dosage of 50 mg/kg body weight was about 5% in the 2–9 year age group and 30% in the 0–1 year group. Infections with typable strains gave rise to therapeutic failure about 3 times as often as infections with non-typable strains. In the 0-1 year group all infections with typable strains gave rise to therapeutic failure.