Legionella in Drinking Water

In July 1976, an outbreak of acute respiratory illness occurred during an American Legion convention in Philadelphia, Pennsylvania. Of 4,400 attendees, and some other individuals not directly associated with the convention, 221 became ill and 34 of these cases died (Fraser et al., 1977). The cause of the epidemic was unknown until later that year, when investigators at the Centers for Disease Control isolated the responsible bacterium, subsequently termed Legionella pneumophila (lung-loving) (McDade et al., 1977).