Legionnaires’ disease

Abstract

Legionnaires’ disease was first recognized following an outbreak of disease among a convention of US army veterans being held in a hotel in Philadelphia in July 1976. Out of 4400 people, 76 were affected, of whom 29 died. The outbreak of pneumonia took 6 months to pin down to a specific organism using animal inoculation and the eventual demonstration of a novel bacterium,1 eventually termed Legionella pneumophila. Legionnaires’ disease is an important community-acquired pneumonia.2,3 The organisms responsible are derived from water environments that are mostly manmade, but the organism is transmitted through the air as aerosols.