Épidémiologie de la flore nasopharyngée au cours des otites moyennes aiguës de l'enfant de décembre 2000 à mars 2001

Abstract

Method. – A French multicentric survey was made between December 2000 and March 2001 on 734 children (6 months–6 years) presenting with acute otitis media (AOM). Results. – A total of 1133 bacterial strains were isolated from nasopharyngeal secretions, the 3 main pathogens were S. pneumoniae (409 isolates, 36%), H. influenzae (328 isolates, 29%) and M. catarrhalis (275 isolates, 24%). The overall NP carriage rate for S. pneumoniae reached 56%. Among the 409 pneumococcal strains, 63% showed reduced susceptibility to penicillin (PRSP). Thirty two percent of PRSP isolates belonged to serotype 19, the other predominant resistant serotypes were 23, 6, 14 and 9. The analysis of PRSP strain distribution showed that resistance concerned all of France and was homogeneous, with an incidence superior to 50% in all regions, except for Alsace. H. influenzae was isolated from nasopharyngeal flora in 45% of children. 43% of H. influenzae isolates produced a β-lactamase with large variations in regional distribution (13–64 % of isolates). The overall NP carriage rate for H. influenzae was 19%. Less than 1% of H. influenzae isolates were ampicillin-resistant without producing β-lactamase. Nasopharyngeal carriage rate for M. catarrhalis was 37%, with 97% of isolates producing β-lactamase. Conclusion. – Evidence of geographical variation in the incidence of PRSP and β-lactamase-producing H. influenzae stresses the need of therapeutic policies adapted to regional epidemiology. The introduction of the heptavalent pneumococcal conjugate vaccine and the diversification of first-line antibiotherapy can only have beneficial effects in terms of cost and bacterial epidemiology.