Prevalence of Legionella in hospital water systems: medicolegal and occupatiojnal considerations

Legionella infection is a significant problem for health systems and it requires a procedure for prevention and environmental control, but it can happen that the usual preventive tools are not effective. The objective of this study is to investigate the frequency of Legionella contamination in water systems of some hospitals in Rome and province and draw some interesting forensic considerations. Seven Italian hospitals and 180 samples selected in 2010 and 2011 were included in the study. Despite the use of hyper chlorination according to the law of the water systems, Legionella was isolated in all hospitals examined and in 2/7 the level of contamination was high. The Italian legislation on worker safety classifies Legionella as biological agent of class 2 also because there are effective prophylaxis treatments. But these data confirm that disinfection is not sufficient. In addition to a required environmental monitoring, it must be a correct clinical approach to infectious diseases recognized in the prudence and diligence of doctor which uses appropriate diagnostic tests, such as urinary antigen, essential for a correct diagnosis and antibiotic therapy. Each nosocomial pneumonia should be investigated etiologically with the detection of urinary antigen and also in medicolegal step becomes essential to take account of this consideration in the evaluation process.