Legionella control in buildings

Legionnaires’ disease caused by Legionella bacteria has increased sharply in Switzerland in recent years. To counteract this spread, the FSVO has launched a research project: a multidisciplinary team is developing basic principles for Legionella control in buildings. 

Legionella control in buildings

Legionella are bacteria that occur naturally in standing water. They can become a problem for human health when they enter and spread in sanitation systems.

Legionnaires’ disease on the increase

Infections with Legionella, the bacteria responsible for Legionnaires’ disease, are occurring more frequently in Switzerland. In 2019, the Sentinella reporting system of the Federal Office of Public Health (FOPH) recorded 582 cases of Legionella infection, 5 to 10% of which had a fatal outcome.

The FSVO and LeCo

In 2017, in response to the growing number of cases of Legionnaires’ disease in Switzerland, the FSVO, which is responsible for drinking water safety, specified limits for Legionella in water from sanitation facilities (including shower and bathing water). These limits are regulated in Swiss food legislation.

To ensure future compliance with the limits, the FSVO partnered with the FOPH and the Swiss Federal Office of Energy (SFOE) to launch the research project LeCo (“Legionella control in buildings”) and to provide CHF 2.6 million in funding from 2020 to 2024.

The Offices’ aim with this project is to provide waterworks operators, civil engineers, plumbers, fitters and building owners with a scientific basis underpinning the hygiene requirements for water in sanitation systems.

A multidisciplinary research project

Various research groups have joined forces to improve the detection methods for Legionella and to establish how to control it effectively in buildings.

Since early 2020, under the leadership of Eawag (Swiss Federal Institute of Aquatic Science and Technology), researchers in the fields of drinking water microbiology, disease agents and human health (Eawag, Swiss Tropical and Public Health Institute), building technology and energy (Lucerne University of Applied Sciences and Arts) and the Legionella unit at the Zurich Cantonal Laboratory have been investigating how best to control the risks associated with Legionella.

Long-term goals

The goal is to better understand Legionella’s behaviour in the water pipes of large buildings:

  • What role does water composition play?
  • Which microflora can compete with the development of Legionella?
  • Which disinfection measures can keep the growth of Legionella under control?
  • Can the origin of contamination be identified by genome sequencing of Legionella (new genome sequences)?

The answers to these questions should help to reduce cases of Legionnaires’ disease in Switzerland in the long term

More information

Last modification 09.06.2022

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