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.