MCLEAN, Va. — With the number of Legionnaires’ disease cases increasing this year in the United States, the Association of Water Technologies (AWT) has responded by releasing a new paper on Legionella and how to minimize the risk of legionellosis from water systems.

The number of cases of legionellosis reported to the federal Centers for Disease Control and Prevention (CDC) this year totaled 624 as of last week, compared to 436 for the corresponding period last year — a 43 percent increase, reports the AWT. In some regions of the country, the numbers are double or triple those reported at this time last year. To help shed some light on the disease and its causes, the association’s paper “Legionella 2003: An Update and Statement by AWT,” provides an overview of Legionella and Legionnaires’ disease including:

  • Background and general facts (history, susceptibility, disease symptoms);

  • Sources of the disease (which can include hot water tanks and potable water distribution systems; cooling towers and evaporative condensers; and whirlpool spas and showers);

  • How it is transmitted (inhalation or aspiration of contaminated water); and

  • How it can be tested/treated for in water systems.

    “With the release of this new and updated document on Legionella, AWT aims to educate and advance the current knowledge we have to help prevent further outbreaks of this disease,” said William E. Pearson II, CWT, president of the Association of Water Technologies and primary author of the paper.

    The paper is available as a free download from AWT’s Web site at and will be presented at the 2003 AWT Water Technologies Convention and Expo in Phoenix in September.

    Publication date: 07/14/2003