Occurrence of Legionella spp. in selected public facilities in Poland in 2009-2013 and 2014-2016: a comparative study

Abstract

Background. This paper evaluated Legionella spp. water system contamination in the public facilities. Material and methods. Samples of warm water from the inner water supply system of 41 facilities in years 2009-2013 and 46 facilities in years 2014-2016 were collected for analyses. The facilities included school dormitories, boarding houses, school-education centers, halls of residence, nursery schools, kindergartens, and correctional institutions. Results. The results of research carried out on tap water in public facilities in 2014-2016 showed that in comparison to 2009-2013 the percentage of facilities from group I increased. In group III facilities a decreasing tendency was observed in comparison to research carried out in 2009-2013. Conclusions. The results indicate that it cannot be explicitly ascertained that the eradication methods of L. pneumophila from tap water systems of the analyzed facilities within the studied period were sufficient. Epidemiological analyses of this type should be successively and systematically continued and based of the largest possible number of facilities.