Nasopharyngeal Codetection of Haemophilus influenzae and Streptococcus pneumoniae Shapes Respiratory Syncytial Virus Disease Outcomes in Children

Background The role of nasopharyngeal bacteria in respiratory syncytial virus (RSV) disease has been underestimated. We measured the frequency and burden of respiratory bacteria in the upper respiratory tract of infants with RSV infection over 7 respiratory seasons, and their impact on clinical outcomes. Methods Children Results S. pneumoniae, H. influenzae, and M. catarrhalis, but not S. aureus, were detected more frequently in RSV-infected children (84%) than healthy controls (46%; P Conclusions Nasopharyngeal codetection of S. pneumoniae and H. influenzae in infants with RSV infection is associated with increased disease severity.