Legionella outbreak in Wetzikon leads to one death

Health authorities in the Canton of Zurich have reported an increase in Legionella infections in Wetzikon, including one death. Since the beginning of 2025, 33 cases have been reported in the area, with eight occurring since late June 2026. The deceased individual was a middle-aged person with pre-existing medical conditions.

While a single common source has not yet been identified, investigations by the Cantonal Medical Service and the Cantonal Laboratory are ongoing. Preliminary analyses suggest a link between several infections and Legionella found in shower water samples. Authorities are focusing on patient interviews and sample analysis of water-carrying systems to pinpoint the cause.

Experts note that Legionella bacteria thrive in warm, moist environments such as water pipes, showers, and cooling systems. Risk is highest for individuals over 50, smokers, and those with weakened immune systems. In response, the city of Wetzikon and the health directorate are developing information materials to promote prevention and awareness.