Quantitative analysis of the bacterial findings in otitis media.

Qualitative and quantitative bacterial analysis of 200 samples of middle ear effusions collected from patients with current otitis media was performed. When middle ear pathogens (S. pneumoniae, H. influenzae and B. catarrhalis) were found during current acute otitis media or otitis media with effusion infection, the quantity of these bacteria was of the magnitude 10(6)-10(8)/ml and 0-5 x 10(5)/ml effusion material, respectively. Mucopurulent effusion material contained 6 x 10(5)-10(8) bacteria per ml whereas effusion from chronically discharging ears exceeded 10(9) bacteria per ml. Serous effusions did not harbour middle ear pathogens. The appearance of the effusion material was dependent on the number of bacteria involved. Quantification of bacteria in various middle ear effusions offers opportunities to make the diagnosis of various otitis media infections more accurate and readily comparable.