[Legionella contamination of hospital hot water supply systems in the light of research conducted in 2008-2010 as part of supervision by the Country Sanitary Inspector in Bydgoszcz].

The aim of the study was to assess the level of Legionella sp. contamination in the hot water supply systems at the premises of inpatient healthcare facilities. In the years 2008-2010 the State Poviat Sanitary Inspector in Bydgoszcz tested the hot water supply systems in 8 hospitals. A total of 88 samples of hot water were collected in the years 2008-2010. The analysis involved temperature measurements and microbiological testing of the hot water. Contamination levels exceeding the applicable standards were discovered in 6 hospitals. The corrective measures introduced allowed for a significant improvement in each case. The hospital hot water systems revealed Legionella sp. contamination levels considerably exceeding the approved standards. Of the 88 water samples tested, 37 contained excessive numbers of Legionella sp. bacteria (i.e. above 100 CFU in 100 ml of water), which constituted 63.6% of the samples tested. In 6 of the 8 investigated hospitals the Legionella sp. contamination of the hot water supply system was found to be on the medium or high level. The analysis of temperature measurements revealed that the lowest temperature readings were associated with high bacterial colonization of the plumbing system. After the implementation of corrective measures, 50 control samples were collected, and in 37 of them the bacterial levels were below 100 CFU per 100 ml of water. The Legionella sp. contamination was found to be associated with low temperature of the hot water.