RESUMO
A prospective tympanometric and microbiologic study of 28 pre-schoolchildren was undertaken to better define the effect of acute URI on induction of eustachian tube dysfunction. Significant negative middle ear pressure was present in 12.7% of tympanograms from well children. However, abnormal tympanograms were detected during 74.7% of acute URIs. The abnormality was present on day 1 or 2 of illness in the majority of cases; 10.1% of illnesses were complicated by OME. Respiratory viruses or Sp were etiologically implicated in 40.5% of illnesses; isolation rates of Pn and HF from well and ill children were similar. Although colonization of the nasopharynx of well children with Pn or HF was associated with a higher incidence of abnormal middle ear pressure, colonization with Pn or HF during URI did not influence the frequency of tympanogram abnormality.