Legionella pneumophila, the infectious organism in Legionnaires' disea
se, is an important cause of both community and nosocomial pneumonia.
Erythromycin is the most frequently used drug for the treatment of leg
ionnaires' disease; however there have been no controlled trials of an
tibiotic therapy, so the optimal antibiotic treatment of legionnaires'
disease is not known. Doxycycline and erythromycin have similar thera
peutic effectiveness, Some of the newer antimicrobial agents, such as
ofloxacin and azithromycin, have excellent activity against L pneumoph
ila.