Changes in nasopharyngeal flora during otitis media of childhood.

The nasopharyngeal flora of healthy children were compared with flora in children with otitis media caused by nontypable Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis. Forty healthy children were followed prospectively and compared with 70 children with 43 episodes of nontypable H. influenzae, 21 episodes of S. pneumoniae and 28 episodes of M. catarrhalis otitis media. Carriage of nontypable H. influenzae (95% vs. 65%, P less than 0.001), S. pneumoniae (91% vs. 52%, P less than 0.005) and M. catarrhalis (86% vs. 52%, P less than 0.001) increased significantly during episodes of otitis media compared with healthy periods. The quantity of nontypable H. influenzae, S. pneumoniae and M. catarrhalis in nasopharyngeal secretions also increased during active infection compared with healthy periods: 3.0 vs. 2.0, P less than 0.005; 3.2 vs. 2.1, P less than 0.001; and 3.3 vs. 2.5, P less than 0.01, respectively. At the same time, nonpathogens of the resident flora, in particular viridans streptococci, declined in carriage: 65% vs. 22%, P less than 0.001. These data suggest that respiratory pathogens become relatively more important in the microenvironment of the nasopharynx during episodes of otitis media. Furthermore the absence of a middle ear pathogen in a nasopharyngeal culture strongly suggests that the pathogen is not present in the middle ear space (negative predictive value greater than 0.96).