ECOLOGY OF LEGIONELLA - FROM DATA TO KNOWLEDGE WITH A LITTLE WISDOM

The respiratory diseases produced by the Legionella genus of bacteria are collectively called Legionellosis. Presently more than 34 species of Legionella have been identified, 20 of which have been isolated fro m both environmental and clinical sources. The diseases produced by Le gionella include the pneumonic form, Legionnaires' disease, and the fl u-like form, Pontiac fever. Because the vast majority of Legionellosis is caused by the L. pneumophila species, this bacterium is the thrust of the discussion. Legionella is a global bacterium. The relationship of the bacterium to its environment has told us many things about inf ectious diseases. Not until Legionellosis and the discovery of its eti ologic agent, Legionella, has such a successful modem-day marriage bee n consummated between the agent and its environment. Nearly two decade s have passed since the term Legionellosis found its way into the voca bulary of the scientific journals, the popular press, and courtroom pr oceedings. Too often the scientific development, engineering implement ation, and societal acceptance are disconnected. The focus of scientif ic research sometimes does not reflect engineering or societal needs a nd thus contributes little to the solution of immediate and important problems. At other times, scientific knowledge that could contribute t o solutions is overlooked because of poor communication between the pr oblem holders, the scientific community, regulatory agencies, the prob lem makers, and the public. The scope of this paper provides insights on the ecological niche of Legionella, describes the organism's ecolog ical relationships in the natural world, and provides wisdom for effec tive control of the bacterium for the industrial and user communities.