The Association of Water Technologies (AWT) has released a paper on Legionella and minimizing the risk of legionellosis from water systems. The number of cases of legionellosis reported to the federal Centers for Disease Control and Prevention for 2003 totaled 624 as of July, compared to 436 for the corresponding period in 2002--a 43% increase. In some regions of the country, the numbers are double or triple those reported at the same time last year.