Disease severity in acute bacterial rhinosinusitis is greater in patients infected with Streptococcus pneumoniae than in those infected with Haemophilus influenzae

Background Streptococcus pneumoniae and Haemophilus influenzae are the most common causative pathogens in acute bacterial rhinosinusitis. A post hoc pooled analysis of four multinational Phase III clinical trials was conducted to compare disease severity in acute bacterial rhinosinusitis caused by S. pneumoniae or H. influenzae . Methods Patients were evaluated for acute bacterial rhinosinusitis clinician-assessed symptom severity and radiologic findings (total opacity, mucosal thickening, and air-fluid levels on maxillary sinus x-rays). Specimens for bacteriologic identification were collected by maxillary sinus tap, or by selective middle meatal cultures (sinus aspirates or swabs). Results Compared with patients infected with H. influenzae (n = 106), patients infected with S. pneumoniae (n = 143) showed a statistically significant higher incidence of severe disease (39.2% vs 23.6%, P = 0.0097) and total opacity (46.2% vs 29.2%, P = 0.0085). Mucosal thickening (47.6% vs 56.6%, P = 0.1616) and air-fluid levels (49% vs 56.6%, P = 0.2500) were comparable between the two groups. Conclusions In acute bacterial rhinosinusitis, infection with S. pneumoniae is associated with more severe clinical symptoms and radiographic total opacification findings than infection with H. influenzae .