Can smoking worsen the symptoms of a lung infection?

Yes.: Smoking worsens just about every single lung disorder, including infections. Smoking paralyzes and damages tiny hair like cells along the lung/bronchial lining that help move dirt, bacteria, dust out of the lung. So you can see how smoking can make a lung infection worse.

Yes : Smoking interferes with the lung's normal ability to cleanse itself. Therefore infections of breathing tubes or lung tissue will occur more frequently, be more difficult to eradicate, and be more debilitating.