Disinfection of Hospital Water Systems and the Prevention of Legionellosis: What is the Evidence?

Abstract

The contaminated hospital water system (HWS) is often identified as the source of Legionella spp.. In this case, disinfection of the HWS is required, aiming at the prevention of nosocomial Legionnaires’ disease (LD). This chapter analyzes the literature for evidence of different disinfection methods and their success in preventing nosocomial LD. The authors found 45 studies describing disinfection methods in HWS, 16 in which the outcome LD was included in this review. Nine authors reported three or more interventions to achieve disinfection of the HWS. Based on the study-quality rating system, rates for each disinfection method was calculated. Chlorine dioxide (rate 2.0) was used in one study with the outcome being LD only, where several disinfection methods for LD control were implemented. Once a system is technically well maintained, and a low Legionella spp. count is achieved, a single method, e.g., copper/ silver ions or high warm-water maintenance temperature (>55°C at distal outlets) for the prevention of LD might be sufficient.