[Bacteriological study in acute otitis media].

Abstract

AIM: A prospective study on bacteriological epidemiology in acute otitis media was conducted in a pediatric hospital emergency service from January 1993 to October 1995. PATIENTS: One hundred and fifty-eight children, aged 6 months to 6 years, with an acute otitis media were included. Culturing and cleansing of the ear canal and tympanocentesis for aspiration and culture of the secretions were performed in 118 children (46 of whom had received antibiotics before for 48 hours). MAIN RESULTS: Middle ear aspirates were sterile in 35% of the children who had not received antibiotics and in 64% of those already treated. Bacteria in middle ear were predominantly Haemophilus influenzae and Streptococcus pneumoniae. Fifty-nine percent of S pneumoniae strains were penicillin-resistant; however, they were responsible for clinical failure in only 8% of cases. No Staphylococcus strains, commensal of the ear canal, could be considered as pathogenic for the middle ear. CONCLUSION: The preciseness with which secretions of middle ear are aspirated reduces the risk of contamination and comparison of ear canal and middle ear cultures allows to identify them. The high ratio of sterile middle ear aspirates after antibiotic treatment raises the question if other factors are responsible for persistent symptoms. The existence of penicillin-resistant S pneumoniae must be known to adjust treatment.