Changes in nasopharyngeal flora during otitis media of childhood

The nasopharyngeal flora of healthy childrenwere compared with flora in children with otitismedia caused by nontypable Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis. Forty healthy children werefollowed prospectively and compared with 70children with 43 episodes of nontypable H. influenzae, 21 episodes of S. pneumoniae and 28episodes of M. catarrhalis otitis media. Carriageof nontypable H. influenzae (95% vs. 65%, P <0.001), S. pneumoniae (91% vs. 52%, P < 0.005)and M. catarrhalis (86% vs. 52%, P < 0.001)increased significantly during episodes of otitismedia compared with healthy periods. Thequantity of nontypable H. influenzae, S. pneumoniae and M. catarrhalis in nasopharyngealsecretions also increased during active infectioncompared with healthy periods: 3.0 vs. 2.0, P <0.005; 3.2 vs. 2.1, P < 0.001; and 3.3 vs. 2.5, P< 0.01, respectively. At the same time, nonpathogens of the resident flora, in particular viridans streptococci, declined in carriage: 65% vs.22%, P < 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 pathogeni. a nasopharyngeal culture strongly suggeststhat the pathogen is not present in the middleear space (negative predictive value >0.96).