THE MICROBIOLOGY OF CHRONIC OTITIS-MEDIA WITH EFFUSION IN A GROUP OF AUCKLAND CHILDREN

Aims. To determine the microbiology of chronic otitis media with effus ion in a group of Auckland children. To determine the antimicrobial se nsitivities of isolated bacterial pathogens to commonly used antibioti cs for this condition. Methods. A descriptive study recruiting subject s from otherwise well children with chronic otitis media with effusion having insertion of ventilation tubes at Starship Children's Health, Auckland. Tympanocentesis was performed, the middle ear aspirate cultu red and antimicrobial sensitivities obtained. Results. Sixty seven chi ldren (11 mo to 8 yr) with chronic otitis media with effusion had tymp anocentesis of 105 ears. 38/105 (36%) of the middle ear aspirate cultu res were positive. Forty nine organisms were isolated with 10 ears hav ing two or more different bacteria identified. Isolated were 17 Haemop hilus influenzae (16 nontype b and 1 type b), 13 Moraxella catarrhalis , nine Streptococcus pnuemoniae and 10 'others'. All S pneumoniae(9/9) , most H influenzae(14/17) and no M catarrhalis(0/13) were sensitive t o amoxycillin. More than 80% of subjects had either a sterile effusion or an organism sensitive to amoxycillin or cotrimoxazole. Conclusions . Middle ear effusions were culture positive in a third of cases of ch ronic otitis media with effusion. The commonest organisms were H influ enzae nontype b, M catarrhalis and S pnuemoniae. This is similar to re ports from other countries. Sensitivity data obtained supports the con tinued recommendation of amoxycillin or cotrimoxazole as first line th erapy for the antimicrobial treatment of this condition.