For this reason, the Federal Food Safety and Veterinary Office (FSVO), the Federal Office of Energy (SFOE) and the Federal Office of Public Health (FOPH) are now providing CHF 2.5 million in funding for a four-year, Eawag-led multidisciplinary project – “Legionella control in buildings (LeCo)”. Participating alongside the Eawag research groups led by Frederik Hammes (Drinking Water Microbiology) and Tim Julian (Pathogens & Human Health) are the Lucerne University of Applied Sciences (HSLU), the Swiss Tropical and Public Health Institute (Swiss TPH) and the Zurich Cantonal Laboratory (KLZH).
Julian, in collaboration with Swiss TPH, will be studying the relationship between legionella concentrations in shower water and the incidence of legionnaires’ disease. More specifically, using mathematical modelling, the researchers wish to determine the likelihood of infection at various legionella concentrations.
The project will also be focusing on the improvement of sampling. For, in a federal ordinance which came into effect in 2017, a limit of 1000 colony forming units per litre is specified for legionella in showers accessible to the public. But bacterial community composition in plumbing systems varies, which complicates sampling. Franziska Rölli of the Institute of Building Technology and Energy at HSLU says: “To increase the reliability and comparability of samples, we need to optimise and standardise collection methods.”
Rölli also emphasises the importance of awareness-raising and communication: architects, planners, plumbers and building operators are often not sufficiently familiar with the issue of legionella. Accordingly, in addition to research activities, the project consortium is committed to disseminating new findings – for example, via workshops or seminars.