Legionellosis

Symptoms

Legionellosis produces the typical symptoms of pneumonia—fever, chest pain, and difficulty breathing—along with severe muscle pain and a significant overall decline in health, with pronounced malaise.

Who is affected?

Legionellosis can affect anyone who comes into contact with the causative bacterium, but it is more common in elderly or immunocompromised individuals who have been exposed to contaminated water or inhaled vapor from such water.

Diagnosis

Diagnosis is made by detecting the bacterium or antibodies against it in the blood, once suspected based on clinical characteristics (age of onset, fever, severe general malaise, muscle pain) or radiographic findings (pneumonia affecting large areas of the lungs). Isolation of the bacterium is relatively recent, as it requires special culture media.

In fact, Legionella was not identified as a cause of pulmonary disease until 1976, during a pneumonia outbreak at an American Legion convention in Philadelphia, from which it gets its name.

Usual treatment

Legionellosis responds well to specific antibiotic treatment. Early initiation of treatment is very important.

Common tests

Chest X-ray, blood tests for antibodies against Legionella, and specific cultures to identify the bacterium.

Prevention

Epidemiological surveillance of detected cases (water pipes, air-conditioning towers, pools, or hot tubs involved) is crucial to disinfect them.

When a case of legionellosis is detected, public health authorities conduct an investigation to locate and eliminate the source.

Legionella does not tolerate high temperatures well and is usually eliminated by temporarily raising the temperature of the water systems. To ensure the bacterium is fully eradicated, these measures should be carried out by specialized professionals.