[Legionella in water of medical facilities--a hazard for patients and personnel?].

Since 1987 warm water samples of public health facilities in Dresden were cultured for Legionellae. In 59 of 220 (26.8%) samples and in 15 of 20 facilities Legionella pneumophila was detected. Most frequently serogroups (SG) 1 (5 times), 6 (4 times), 8 (times) and 5 (twice) were found. By reason of the ubiquity of the aerogenic transmissible Legionellae, nosocomial legionellosis can occur at any time. Most legionellosis patients suffered from severe underlying diseases. Therefore the risk for immunocompetent staff should be assessed lower. In dentists who used Legionella-contaminated dental units we could demonstrate more frequently high antibody titers against Legionellae. Measures to eradicate Legionellae from air conditioning systems and hot water supplies are discussed.