BACTERIAL EPIDEMIOLOGY OF ACUTE OTITIS-ME DIA IN CHILDREN

Acute otitis media are very frequent in children under 5 years of age. Following viral infection, bacterial species belonging to the nasopha ryngeal flora colonize the middle ear mucosa. The predominant species are H. influenzae, S. pneumoniae and M. catarrhalis. Acute otitis medi a are usually benign, but rare complications may develop such as masto iditis, meningitis, or sequelae (deafness). The recent emergence of pn eumococci resistant to penicillin G in France has altered classical an tibiotherapy based on penicillin G or its derivatives. In fact, the ge ographical distribution of resistant pneumococci is heterogeneous, wit h highly endemic areas and almost unaffected regions. Almost 37 % of p neumococci isolated from the nasopharyngeal flora of children display an abnormal susceptibility to penicillin G (MIG > 0.1 mg/l), including a significant percentage of strains with MIC > 1 mg/l. Most resistant isolates belong to serotypes 19 and 23 F. The antibiotic susceptibili ty of H. influenzae is stable for several years. Almost 30 % of isolat es are beta-lactamase-producers and 10-15 % serotype b of isolates bel ong to the invasive. M. catarrhalis is responsible for 10 % of acute o titis, often in association with other bacteria. Most isolates produce beta-lactamases, but this pathogen remains usually susceptible to the classical antibiotherapy. Antibiotic resistance is a rapidly evolutiv e, dynamic phenomenon. The probabilistic antibiotherapy must be based on the knowledge oi the regional epidemiology and diversified to reduc e the selective pressure of antibiotics.