[Incidence of Legionella in warm water systems in Saxony-Anhalt]

The incidence of Legionella in warm water systems of Sachsen-(Saxony-)Anhalt was investigated. The Legionella were isolated from water samples using plate cultures followed by serotyping methods. In high-risk areas of Legionella infections such as hospitals and homes for the aged, 48% respectively 43% of the samples were positive. Warm water systems of 61% of the hospitals and 43% of homes for aged people were found to be contaminated with Legionella. The number of Legionella were most frequently (50.7%) between 10 and 100 colony-forming units/ml (cfu/ml). High-level Legionella contamination (> 1000 cfu/ml) were detected only in 0.6% of the samples. Legionella pneumophila serogroup 1 (L.p. SG 1) was identified rarely. The reasons for positive Legionella findings are old drinking water heating systems and conduits. To decrease Legionella growth, reconstruction of the old systems according to the recommendations [1, 2] is imperative.