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In periods of high heat, bacteria can develop in stagnant water, such as those of the genus Legionella, causing a serious respiratory infection. Update on legionellosis with Liath Guetta, pulmonologist and member of the Doctissimo expert committee
Summer is conducive to temperature changes. To fight against the heat, multiplying the devices all over the house often appears to be “the” solution. A habit, which is not without health consequences: bacteria Legionella, found in many hot springs, love to unfold there. In France alone, between 1600 and 2000 people contract Legionellosis each year.
Legionella love hot springs
Legionnaires’ disease is a disease of bacterial origin, which leads to a serious lung infection.
“The recent emergence of this disease is explained by its affinity for modern water supply systems”emphasizes the Institut Pasteur.
Indeed, Legionella bacteria love hot springs – that’s why they are found at the bottom of water tanks, in bodies of water, in moss, sawdust, wet soil but also in systems water distribution (refrigerators, air conditioners, jet baths, cooling towers, air conditioners, hot water tanks, etc.) where they proliferate on contact with organic deposits, iron, zinc and aluminum and other micro-organisms.
Legionellosis, a potentially fatal disease
These heat-resistant bacteria thrive especially in lukewarm water (30-60°) and are caught by inhalation – through the nose and respiratory tract.
“After inhaling the aerosols, the bacteria present are absorbed at the level of the pulmonary alveoli then they invade the macrophages, cells of the immune system, which they end up destroying”warns the Pasteur Institute.
Nevertheless, Dr Liath Guetta, pulmonologist and member of the committee of experts of Doctissimo, wants to be rather reassuring in the face of the risk of contamination.
“Legionellosis is extremely rare. In addition, no precaution can protect against it… The bacteria are invisible. We cannot therefore turn off the air conditioning during a heat wave for this reason”.
The only thing that can be avoided? “Hot tubs, especially public ones, which are veritable breeding grounds for germs“, indicates the pulmonologist.
Two to 10 days after contamination, the first symptoms appear.
They look like a simple flu syndrome (fever, dry cough, etc.) followed quickly by an increase in fever (39.5°C). Feelings of discomfort, abdominal pain (nausea, vomiting, diarrhoea, etc.) and neurological disorders may then appear. If not treated in time, these can develop into a coma.
Also, the patient’s kidneys or lungs may sometimes stop working.
Men over the age of 50 – as well as smokers or people already weakened by the disease (diabetes, cancer, etc.) – are more prone to complications.
“To cure it, an antibiotic treatment is generally prescribed”, specifies Dr Guetta, before adding “that legionellosis is a notifiable disease”.
In other words, it must be reported to the ARS, which will look for the origin of the contamination.