Legionella causes….

Legionella can cause a bacterial infection of the respiratory system with the most common symptoms to be: fever, pneumonia etc. The symptoms appear 2-10 days after the infection and the disease can be fatal to 5-30% of the patients.

Legionella is transferred through air by inhaling the bacteria, when contaminated water is scattered in the air in the form of droplets. The bacteria is found in water tanks, freezing units, humidifiers and air condition units of large scale that water stays stable and in solid deposits inside pipes and tanks. It stays alive in water temperatures 20-45o C, with an optimum of 35o C.

Preventive measures

The proper maintenance and operation of water pipes and A/C units in hotels, hospitals, sports establishments etc., is the main preventive action that can be taken against Legionella. The most typical preventive action is that of choosing the most suitable disinfecting method for water in order to eliminate all the pathogens keeping at the same time the qualitative characteristics of water (taste, odor). It would be helpful to keep a regular monitoring (at least once per 6 months) of the microbiological quality of the water inside a building.

According to a recent State decision on water quality, there has been established a maximum limit for the Legionella bacteria, expected to be found in internal water pipes of hospitals, health units, elderly homes, hotels, military camps etc.

Parameter Parametric value
Legionella 1000 cfu /1L Hospitals, health centers etc.
1000 cfu /1L Hotels, military camps etc.


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