Legionellosis is a disease caused by Legionella pneumophila bacteria. There are 2 clinical forms of legionellosis. The benign form is called “Pontiac fever”. It is characterized by flu-like symptoms of fever and cough. It generally appears 1 to 2 days following exposure to the bacteria. Recovery usually takes 2 to 5 days and most cases do not require treatment.
The most serious form of legionellosis, Legionnaires' disease, is characterized by a lung infection, pneumonia. It generally appears 2 to 10 days following exposure to the bacteria and can be severe, especially in vulnerable individuals.
Legionellosis can occur at any time of the year but is more common in summer and fall. Most cases in Québec are isolated and sporadic. Outbreaks are rare.
The following symptoms may be associated with legionellosis:
The complications associated with Legionnaires' disease are:
Legionnaires' disease can cause death in 10 to 15% of cases. This percentage may vary depending on several factors, including age, health and the timeliness of treatment.
Most cases are treated successfully with antibiotics.
Legionnaires' disease is contracted by breathing in airborne microdroplets of water contaminated with Legionella bacteria. The disease is not spread from one person to another.
The bacteria multiply, especially at temperatures ranging between 32°C and 45°C.
While Legionella bacteria are found in natural water sources (lakes, rivers, streams) and in the ground, the main sources of infection are artificial water sources, such as water cooling towers, hot tubs or water heaters.
The main sources of infection are:
There is no vaccine or preventive treatment to protect people from legionellosis. However, the risk of contracting the disease can be reduced by dealing with possible sources of infection.
Here are some recommendations to help prevent legionellosis:
Some people are more at risk of having legionellosis:
Last update: August 9, 2017 1:25 PM
The information on this website by no means replaces the advice of a health professional. If you have questions regarding your health, contact Info-Santé 811 or see a health professional.