Overview

A bacterial infection may develop following infection with viral influenza. Signs of a bacterial infection include:

• Feeling short of breath.
• A fever that doesn't go away.
• A cough that lingers more than 7 to 10 days after other symptoms have cleared, especially if it is bringing up mucus (productive).
• Yellow, green, rust-colored, or bloody mucus that is coughed up from the lungs, especially while other symptoms are getting worse.
• Sinus, throat, or ear pain that is new or doesn't go away.

These infections may sometimes need treatment with antibiotics.