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Friday August 18, 2017

Legionellosis, otherwise called Legionnaire's disease or Pontiac fever, is a bacterial infection that causes fatal pneumonia when proper treatment is not given. Majority of legionellosis cases are caused by the bacterium Legionella pneumophila that can be found in warm water bodies such as rivers, lakes, hot springs, etc. The bacteria are also found in artificial water systems such as in whirlpool spa, cooling tower, condenser, air-conditioner, and hot and cold water fountains in buildings.



People contract legionellosis from inhaling mist or water droplets from infected water systems. In 1976, a pneumonia outbreak in the U.S.A. was link to an infected water system in a convention center where the American Legion held a convention. That is how legionnaire's disease got its name.

Cause and mode of infection of legionellosis

Legionellosis is caused by bacteria that belong to the genus Legionella. The bacteria thrive by infecting protozoa in fresh waterways or they can attach themselves in biofilms inside faucets or shower heads and air-conditioning systems. The bacteria enter the human body through inhalation of mist or tiny water droplets from infected water systems. Once the bacteria are inside the human body, they start infecting the human cells just like they do on their protozoa host. Infections are common in closed, crowded buildings where the air-conditioning systems, humidifier, and other water systems are not disinfected regularly. Hospital-acquired infection is also common in legionnaire's disease.

Symptoms of legionellosis

Legionnaire's disease results into the development of pneumonia. Like all forms of pneumonia, it starts to show as flu-like illness: headache, chills, high fever, coughs, fatigue, loss of appetite, and sometimes diarrhoea and vomiting are observed. Further laboratory examination will show kidney and liver function impairments and electrolytes imbalance. And a chest X-ray will reveal signs of pneumonia. These symptoms will start to appear 2 to 14 days after the bacteria entered the body depending on the state of immunity of the infected person.

Complications from legionellosis

If not treated well, legionellosis can result to respiratory and kidney failure and septic shock. Respiratory failure results from the development of pneumonia that decreases the lungs capacity to properly release oxygen and take out carbon dioxide from the body. The reduced blood oxygen level can cause septic shock, which is fatal if immediate intervention is not given. The kidney function can also decrease due to the infection and low oxygen level in the body.

Treatment of legionellosis

Legionellosis is treated by giving a patient a course of antibacterial medication. If the patient has developed complications, an aggressive form of treatment in a hospital setting is needed. The patient may need life support and kidney dialysis to combat the complications.

Prevention of legionellosis

The best way to prevent legionellosis is to strengthen ones immune system by eating balance diet and maintaining a healthy lifestyle. Regular cleaning and disinfection of water and air-conditioning systems in a building must be observed at all times also. Suspected cases of legionellosis must be reported to proper authority, and extensive disinfection must be launch in the identified source of infection.

Online Resources

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