Elimination of Legionella in a hospital ward

The first hospital-acquired Legionella pneumonia in Poland was detected in the ophthalmology ward of a large hospital. Analysis of medical files revealed previous suspected pneumonia cases in the ophthalmology ward. Biological samples confirmed Legionnaires’ disease. The source proved to be the old hot water system. Chemical and heat-shock treatment of the pipelines diminished the bacterial load but further technical interventions were necessary to eliminate all bacteria. The engineers removed dead legs from the pipelines, as well as the large old metal hot water tanks. The hospital installed an automatic chemical disinfection system. Legionella disappeared and no new cases were observed.