Colonization by Legionella spp. of water networks in residential buildings of the Province of Pisa, Italy

Abstract

Background: Despite the increase of community acquired cases of legionellosis in Italy over the last years, the Italian guidelines do not give indications for prevention and control of Legionella in the hot water networks (or centralized conditioning systems) of residential buildings. We performed a survey on eight medium sized apartment buildings in the Pisa district to assess the prevalence of Legionella spp. in the water network and the respondance to drinking water requisites at the point of use, according to the Italian norms.

Methods: For each building two hot water and three cold water samples (located at water entrance from the aqueduct network into the building pipework, at the exit from pressure autoclave, and at a remote tap) were collected.

Results: Legionella was detected in 20% of residential buildings, mostly in those with a central hot water production system.

Conclusions: The study highlights a condition of potential risk for susceptible population subgroups and supports the need for measures of risk assessment and control.

Keywords: Legionella; Residential buildings; Water risk.