On 23 February 2023, Italian Legislative Decree no. 18 (GU no. 55) was issued, listing the methods of implementation of Directive (EU) 2020/2184 of 16/12/2020, introducing Legionella as one of the microbiological parameters to take into consideration when assessing the quality of water intended for human consumption and requiring a risk assessment of water supply systems.
The monitoring focuses, in particular, on priority areas: hospitals, healthcare institutions, retirement homes, childcare facilities, schools, educational institutions, buildings with a lodging facility, restaurants, bars, sports and shopping centres, leisure, recreational and exhibition facilities, penal institutions and campgrounds.
It therefore involves guaranteeing the increased monitoring of high-occupancy places, or by categories potentially more vulnerable to infection.
Annex VIII of Italian Legislative Decree 18/2023 lists the mandatory actions and recommendations for the different types of facilities, with reference to ISTISAN report 22/32 (Guidelines for the assessment and management of water safety risk in internal distribution systems in priority and non-priority buildings and some ships pursuant to Directive (EU) 2020/2184).
The Legionella parameter is set at 1,000 CFU/litre.
Corrective measures may nevertheless be necessary even for values below this limit, for example, for facilities housing vulnerable individuals or in the case of infections and outbreaks. In these cases, the source of infection must be confirmed and the strain of Legionella identified.