Community-acquired pneumonia in ambulatory patients: relative importance of atypical pathogens

Abstract

The presence of atypical pathogens in community-acquired pneumonia is difficult to diagnose; culture is time-consuming and requires considerable expertise and serological identification may be inaccurate. Nevertheless, the increasing importance of atypical organisms has been recognised in recent years. Variations in aetiology have been detected in different geographical regions and different patient populations. The season of the year may also influence aetiology, and some infections follow a cyclical pattern. When an atypical pathogen is suspected, a macrolide antibiotic is an appropriate choice as, in addition to activity against these organisms, they are usually effective against the Gram-positive and Gram-negative respiratory pathogens implicated in community-acquired pneumonia.