Swiss care homes tighten Legionella checks after 2025 report

Swiss care homes have stepped up their Legionella controls after a national report found serious deficiencies in 2025, SRF reported. Half of the facilities inspected had inadequate self-monitoring systems, while almost one in four exceeded the maximum permitted Legionella level.

The risk of developing legionellosis rises significantly with age. Care homes often occupy large buildings with extensive water systems, whose use varies depending on whether individual rooms are occupied.

Care homes in Geneva have introduced a strict protocol to prevent water from standing in pipes and allowing Legionella to multiply. At Maison de Vessy, a care home on the outskirts of Geneva, hot water is kept between 55 and 60 degrees Celsius. The hot-water tanks are thermally disinfected every week by heating the water to 80 degrees, which kills the bacteria. The systems are also descaled every five years to prevent deposits.

Staff take samples in the rooms furthest from the water system to check that the water arrives at the correct temperature and that it does not remain stagnant in the long pipes. Maison de Vessy consists of four separate buildings and has kilometres of piping.

Before a new resident moves in, or after a room has been unoccupied for an extended period, hot water is run for five minutes from both the shower and the sink. The room is then ventilated.

Swiss law requires every social-medical facility to carry out self-monitoring. According to Geneva cantonal chemist Patrick Edder, the requirement has been in place since 2017 or 2018.

Edder said inspections carried out in 2018 and 2019 found that none of the facilities were conducting self-monitoring. When inspections resumed in 2023, almost all facilities had introduced a self-monitoring system, although some deficiencies remained.

Legionella can cause two forms of illness. Legionnaires’ disease is the more serious form and can lead to severe pneumonia. Symptoms usually appear two to 10 days after infection and include fever, coughing, muscle pain and headaches. Pontiac fever is milder, causes flu-like symptoms and generally clears up on its own within a few days. Older people, smokers and those with weakened immune systems are particularly vulnerable.