LEGIONELLA SPP. IN SELECTED PUBLIC UTILITY BUILDINGS IN POLAND IN 2009-2013

Background. Civilizational changes, including urbanisation and industrialisation, created the

conditions for the development of new pathogens colonising water networks which endanger

human health and life. The aim of the study was to assess the contamination of water supply

systems in public buildings by Legionella spp. a pathogenic group of Gram-negative bacteria.


Material and methods. The material samples were taken from the hot water supply systems

of 41 buildings: school dormitories, boarding schools, educational centres, student dormitories.


Results. In all analysed years, there were samples in which the applicable standards were

exceeded, as specified by the regulation on the quality of water intended for human consumption.

The highest percentage of negative samples was found in 2012, with as many as 81.1%, and the

lowest one in 2011 − 35.3%. Positive samples obtained in the first and subsequent tests were

detected in 20.0% of the tested facilities. The change from positive to negative values was found

in 30.0% of the tested water networks. There were also cases of negative samples both in the

first and subsequent tests, which was detected in 50.0% of the facilities.


Conclusions. 1. An excessive amount of the officially permissible value of Legionella was found

in 53.9% of the examined hot water samples. 2. The obtained results confirm the necessity of

modernising and doing elementary repairs in water supply networks.