Microbiology of serous otitis media in children: correlation with age and length of effusion.

The purpose of this study was to correlate the microbiology of serous otitis media in children with the duration of the condition and the patient's age. Aspirates of serous ear fluids from 114 children were examined for aerobic and anaerobic bacteria. Bacterial growth was noted in 47 patients (41%). Aerobic organisms only were recovered in 27 aspirates (57% of the culture-positive aspirates); anaerobic bacteria only in 7 (15%); and mixed aerobic and anaerobic bacteria in 13 (28%). A total of 83 bacterial isolates were recovered, accounting for 1.8 isolates per specimen (1.2 aerobes and 0.6 anaerobe). There were a total of 57 aerobic isolates, including Haemophilus influenzae (15 isolates), Streptococcus pneumoniae (13), and Staphylococcus sp (12). Twenty-six anaerobes were recovered, including anaerobic gram-positive cocci (10), Prevotella spp (8), and Propionibacterium acnes (4). The rate of positive cultures (20 of 36; 56%) was higher in patients younger than 2 years of age than in those older than 2 years of age (27 of 78; 35%). Streptococcus pneumoniae and H influenzae were more often isolated in children younger than 2 years of age and those with effusion for 3 to 5 months, whereas anaerobes were recovered more often in those older than 2 years of age and those with effusion for 6 to 13 months. These data illustrate the effects of the length of effusion and age on the recovery of aerobic and anaerobic bacteria in serous otitis media.