Legionella and pneumonia: everything you need to know

Legionellosis is a disease caused by the bacterium Legionella pneumophila, which can be found in the water of building water systems (for example hotels and hospitals), cooling towers, whirlpool systems, dental units, tanks, but also in nebulizers and humidifiers. Contagion is unlikely to occur through contact with an infected person. Legionellosis mainly affects people over 50 and / or with conditions that weaken the immune system (immunosuppressive therapies, smoking, alcoholism, chronic bronchitis, cardiovascular and kidney diseases, diabetes, tumors). Symptoms appear quickly: chills, fever, malaise, headache and widespread aches, followed by dry cough, chest pains, sometimes diarrhea and worsening of general condition. The diagnosis is made with the urinary antigen test, with the search for the bacterium in the respiratory secretions and for anti-Legionella antibodies in the blood. If the infection treated with specific antibiotics usually heals within a month, but mortality is 10-11% with peaks over 50% for hospital-acquired forms.