Legionella pneumonia--a neglected diagnosis?

A brief survey of the epidemiology, clinical manifestations, differential diagnosis and treatment of infections with Legionella species is given, with particular emphasis on Legionella pneumophila. Because of recent epidemiological evidence that this species may be an important cause of both community-acquired and hospital-acquired pneumonia, particularly in the immunosuppressed patient, it is suggested that this microbial agent should be considered more often in the differential diagnosis of pneumonia. This has practical implications for therapy, since the drug of choice in Legionella infections is erythromycin, with doxycycline as an alternative. Rifampicin may be added to one of the drugs mentioned, in serious infection.