Abstract
Specimens from acute otitis media (AOM) examined in the first quarter of the years 1986, 1987, 1988, and 1989 were reviewed in order to point out any changes in the bacteriological etiology. A total of 1722 specimens were taken in the community and in the hospitals of a county of 500000 inhabitants in the 4-year-period: 447 (1986), 420 (1987), 388 (1988), 467 (1989). The majority of the specimens came from children < 10 years of age. The specimen sampling technique differed between the various otologists, but their sampling techniques were constant through the years. Haemophilus influenzae was the most frequent isolate and held a constant incidence of 29.9% with little variation. In 1986–88 Streptococcus pneumoniae was the second (19.8%) and group A streptococci (GAS) the third (9.8%) most common agent in frequency. In 1989 a change in the etiologic agents was seen as GAS increased in frequency to 18.8% (p<0.001), while no significant changes occurred in the frequency of H. influenzae and S. pneumoniae. 33% of the specimens were negative in the whole period. It is too early to decide whether a transient epidemic has occurred or whether the findings announce a more constant change in etiology.