Secondary sinusitis due to _______ bacteria will be foul smelling

• A. Aerobic
• B. Anaerobic
• C. Viral
• D. Fungal

Answer: (B)

Foul-smelling sinus discharge is a classic clue for anaerobic bacterial infection. In the inflamed sinuses, mucus becomes stagnant and the oxygen level drops, creating an environment where anaerobic bacteria such as Bacteroides, Prevotella, and Fusobacterium can thrive. These organisms produce volatile sulfur compounds and other odorous metabolites, giving the discharge its distinctive smell. Aerobic bacteria, viral infections, or fungi don’t characteristically produce that same malodor in this setting, so the presence of a foul odor points toward anaerobic bacteria as the cause of the secondary sinusitis.