Epidemiology, prevention and control of legionellosis: memorandum from a WHO meeting.

This Memorandum describes the following aspects of legionellosis: clinical presentations of legionella infection, general epidemiology (including nosocomial outbreaks and travel-associated legionnaires'' disease), surveillance and reporting of cases, the organism and its environment, and measures for prevention and control. These topics were discussed by experts at a meeting in Geneva on 27-29 November 1989. This article also includes their conclusions and recommendations for research in critical areas including surveillance and preventive activities that have been found to be effective.