Staphylococcus aureus is a major pathogen in severe acute bacterial rhinosinusitis.

PURPOSE: The purpose of this study was to investigate the epidemiology and microbiology of severe acute bacterial rhinosinusitis in patients admitted to a Danish tertiary hospital. METHODS: A retrospective study was performed including all cases of acute rhinosinusitis admitted to the ENT-department of Aarhus University Hospital, in the period 2001 to 2011. RESULTS: In total, 143 cases of acute rhinosinusitis were identified of which 51% were children. The most prevalent bacterial strains were Staphylococcus aureus followed by group A streptococcus, Haemophilus influenzae and Streptococcus pneumonia. Morexella catarrhalis was only rarely cultured. Anerobes were not assessed routinely. Of all patients, 47.8% presented with orbital complications and 2.1% developed intracranial complications. Patients infected with group A streptococcus had significantly higher leukocyte and neutrophil counts than other patients. All cultured S. aureus were resistant to penicillin, but sensitive to methicillin. CONCLUSION: Our results imply that S. aureus and group A streptococcus are important pathogens in severe and complex cases of ABRS, in addition to the accepted pathogens S. pneumoniae and H. influenzae. On the contrary M. catarrhalis appears less significant. These findings have important implications regarding the selection of relevant treatment strategy in secondary care, which may currently be underestimating the role of S. aureus.