Legionella is a genus of aquatic bacteria which is frequently found in water distribution systems of large and complex buildings such as hotels, hospitals, office blocks, multi-occupancy accommodation buildings, commercial buildings, shopping malls or passenger ships, quite often after they have already caused small- or large-scale epidemics.
Here is an outline of typical cases that highlight the current extent of the problem:
- New York City – Central Harlem, 08.2025: Legionella was found in cooling towers of 12 buildings, including a university, a clinic and Harlem Hospital, following an outbreak with 99 confirmed cases and 4 deaths.
- London – Ontario Canada, 01 έως2025: Legionella at the Sofina meat processing plant caused an outbreak with at least 109 confirmed cases and 4 deaths.
- Osaka Expo, 07.2025: Legionella was isolated in fountains and artificial shallow water pools at the site of the trade fair.
- Crete – Hersonissos, 2025: Legionella was isolated from 50% of the water samples collected from various tourist accommodations, following the hospitalization of a tourist in the ICU.
- Vorarlberg – Western Austria, 02.2025. Legionella in cooling towers and private homes was implicated in 41 hospitalised cases.
- Bibby Stockholm, 08.2023, Legionella was detected in the water supply of a vessel hosting asylum seekers in Dorcet, UK.
Already in the 1st quarter of 2026, relevant competent authorities report that they are investigating an unusually high number of cases of Legionnaires’ disease in two areas of London.
With the disease having high mortality and patients facing many months of hospitalization, there are clearly significant personal and public health implications.
For those, however, who neglect the proper maintenance of water supply infrastructure, there are also significant legal and financial implications. They may be forced to indefinite closures, loss of income and revenue and will often pay increased repair charges, legal costs and insurance compensations.
So, take the appropriate preventive measures to mitigate the risk of Legionella!
Keep water supply networks safe!
