Legionella was identified with the amoeba and representatives of the genus Francisella. It is the main agent that causes the legionnaire’s disease, and the lighter form called the Pontiac fever. It is transmitted by air, being easily inhaled. Apparently an important source would be cooling towers and air conditioning. As natural sources it can be found in flowing waters or ponds. Once inside the body, the bacteria incubate for about 2 weeks. Symptoms include flu-like symptoms: fever, chills and dry cough. In the advanced stages, gastrointestinal problems, nerve damage, diarrhea, nausea, general malaise and worsening every day with respiratory decompensation occur, most affected by children under 12 and the elderly. It seems that the main culprit of the legionnaire’s disease is Legionella pneumophila, with a very high spreading power .
At the European level, the European Working Group for Legionella Infections (EWGLI) was created to oversee the possible sources of Legionella. It has developed a guide to the actions to be taken when Legionella colonies exceed a certain CFU / ml value at 30 ° C (with a minimum of 48 hours of incubation). The seemingly healthy humans carrying this bacterium are spreading through sneezing or simple conversation saliva droplets that float in the air. These are taken over by air conditioning systems and re-circulated and inhaled. To prevent the development and survival of Legionella bacteria, it is recommended that in the cooling and heating systems (air conditioners, both industrial and apartment-type), boilers etc. should be disinfected at least once a year .