Investigate of nasopharyngeal flora in infants and children with influenza

Abstract

To clarify the bacteriological interpretation of nasopharyngeal flora from infants and children with influenza (n = 38), nasopharyngeal swabs were obtained. From 38 patients, 83 strains of bacterias were obtained. Chief pathogenic bacteria isolated from infants and children with influenza were B. catarrhalis (28 strains), S. pneumoniae (22 strains), H. influenzae (19 strains), S. aureus (6 strains) and chief nonpathogenic bacteria isolated from infants and children with influenza were Corynebacterium spp. and alpha-streptococcus (3 strains each) and Moraxella sp (2 strains). From infants and children without influenza (n = 34), 83 strains were obtained. The chief pathogenic bacteria isolated from infants and children without influenza were B. catarrhalis (23 strains), H. influenzae (22 strains), S. pneumoniae (18 strains), S. aureus (7 strains) and chief nonpathogenic bacteria isolated from infants and children without influenza were Corynebacterium spp. and Moraxella sp (5 strains each), alpha-streptococcus (2 strains) and Neisseria sp (1 strain). There was no significant difference in nasopharyngeal flora between infants and children with influenza and infants and children without influenza. In cases showing detection of multiple bacterial strains, common combinations were one or more of B. catarrhalis, S. pneumoniae, H. influenzae, S. aureus and nonpathogenic or weakly pathogenic bacteria. There was also no significant difference in combinations of nasopharyngeal flora between infants and children with influenza and those without influenza. We emphasize that we must study whether a difference in nasopharyngeal flora between infants and children with influenza and infants and children without influenza develops with time. Therefore, we must repeatedly obtain nasopharyngeal swabs from infants and children with influenza and infants and children without influenza.