[Generally accepted engineering standards and Legionella in drinking water : findings from Frankfurt am Main].

To investigate the association between the engineering standards of drinking water systems and the extent of the Legionella colonization, we subjected our 2006 published data of the drinking water monitoring of the city's public health services for Frankfurt on Main, Germany, to closer analysis. A total of 413 records were available, with both technical data and results of the Legionella colonization. When comparing the classes of technical deficiencies of the drinking water installations with the Legionella colonization results, 93% of the Legionella data "not dedectable in 100 ml" were found in the group of drinking water installations that were technically assessed as "free of deficiencies". Thus, "good" technical engineering is associated with low or lack of Legionella colonization with a high probability even with hints for a dose-effect phenomenon-the more engineering deficiencies that exist, the higher the Legionella contamination.