Relationship between physical-chemical parameters of hot water and growth of aerobes and legionella neumophila: experiences in three spanish hospitals

Articulo presentado al 25º Congreso Internacional de Dirección e Ingeniería de ProyectosLa presencia de Legionella Neumophila en el agua caliente sanitaria tiene influencia en la posible aparición de legionelosis en las personas ingresadas en los hospitales. Se ha estudiado la relación entre los parámetros físico-químicos del agua y el recuento microbiológico de aerobios y Legionella Neumophila. Dentro del programa de vigilancia del agua de consumo, se realizan, desde hace años, analíticas de la composición química del agua fría y caliente en los hospitales de Huelva: Juan Ramón Jiménez, Infanta Elena y Vázquez Díaz. Asimismo, se hacen cultivos de Legionella Neumophila con la frecuencia reglamentaria. Esto permite conocer el grado de cumplimiento de la normativa vigente en España para tratar de evitar que las instalaciones de agua de consumo se conviertan en focos diseminadores de patógenos. Se explican las determinaciones que se han hecho, los resultados encontrado y las actuaciones más adecuadas para minimizar el riesgo de proliferación de la bacteria. Se observa una casuística variada en lo que se refiere a poblaciones de Legionella spp en el agua caliente sanitaria de las instalaciones hospitalarias. Los resultados hallados permiten vislumbrar los procedimientos que podrían evitar o minimizar el crecimiento incontrolado de Legionella Neumophila en el agua caliente sanitaria de los hospitales.The presence of Legionella Neumophila in domestic hot water has an influence on the possible appearance of legionellosis in people admitted to hospitals. The relationship between the physicochemical parameters of water and the microbiological count of aerobes and Legionella Neumophila has been studied. Within the drinking water surveillance program, analyzes of the chemical composition of hot and cold water have been carried out for years in the hospitals of Huelva: Juan Ramón Jiménez, Infanta Elena and Vázquez Díaz. Likewise, Legionella Neumophila cultures are made with the regulatory frequency. This allows knowing the degree of compliance with current regulations in Spain to try to prevent drinking water facilities from becoming sources of pathogens. The determinations that have been made, the results found and the most appropriate actions to minimize the risk of proliferation of the bacteria are explained. A varied casuistry is observed with regard to populations of Legionella spp in the sanitary hot water of the hospital facilities. The results found allow us to glimpse what procedures could avoid or minimize the uncontrolled growth of Legionella pneumophila in the sanitary hot water of hospitals

Effect of the change of the water supply pipes of the Juan Ramón Jiménez Hospital in the proliferation of Legionella

The impact of the modernization of the water systems was assessed through microbiological screening of the flowing water for Legionella Neumophila at Juan Ramón Jiménez Hospital in Huelva. As a consequence of the high number of this microorganism detected in previous periodic creenings, despite quite frequent chlorine-based and thermal disinfections, the decision was taken to substitute the original hot and cold water distribution pipes of galvanized steel for others with a higher spectrum of resistance to chemicals. Thus, 316L stainless steel and cross-linked polythene became the obvious choice, also considering the fact that they are less prone to biofilm formation. Similarly, water filters were placed at the hospital’s general water intake point and at the hot water inlet facilities. New hot water storage devices were assembled. In this paper, information is provided on their layout and the building materials used. Considerations are presented on the most appropriate kind of materials to minimize the risks of bacterial proliferation. The implementation of the measures described in this paper has resulted in a drastic decrease of Legionella Neumophila population in flowing water