Water disinfection methods and their affect on legionellosis

Legionellosis is a respiratory disease caused by the bacterium Legionella spp., which is primarily found in water distribution systems. The objective was to describe whether water disinfection methods used in cooling systems are related to hotel compliance with Spanish health legislation for the prevention of legionellosis. Principal components and correspondence analyses were done on samples from air-water cooling systems (cooling towers, evaporative and adiabatic condensers) at hotels (n = 26) located in the province of Malaga (Spain), in relation to water disinfection methods (chlorination, ultraviolet radiation, ozonation, bromination and copper-silver ionization). The period studied was between 2004 and 2009. A positive association was found between the different water disinfection methods and facilities as well as between those factors and certain hotel categories. Chlorination corresponded to two-, three- and five-star hotels and cooling towers and evaporative condensers. The four-star hotels showed a relation to ozonation and copper-silver ionization, identifying the latter with adiabatic condensers. Luxury hotels corresponded with ultraviolet radiation, and this was not associated with specific risk facilities. The degree of correspondence suggests a specific relationship between the prevention of legionellosis at high-risk hotel facilities and water disinfection systems.