Wetzikon investigates cluster of Legionellosis cases

Authorities in Wetzikon, Switzerland, are investigating a cluster of four new Legionellosis cases reported since late June. Specialized agencies are working to identify the source of infection by interviewing patients about their locations prior to illness and testing shower water in their homes.

Extensive testing has been conducted at various public facilities, including nursing homes, the GZO Hospital, the Wetzikon outdoor pool, and wastewater treatment plants in Wetzikon and Hinwil. Additionally, cooling systems, car washes, and the municipal drinking water system—including hydrants and fountains—have been sampled. So far, no Legionella bacteria linked to the illnesses have been detected in these public sites, and the drinking water remains safe to consume.

The city has noted that Legionella can multiply in domestic water installations when temperatures remain between 25 and 45 degrees Celsius or during periods of water stagnation. Property owners and managers are reminded of their responsibility to maintain domestic systems, particularly hot water boilers, to prevent bacterial growth.