Legionellosis

What is it?

Legionellosis is an infection caused by Legionella bacteria. There are two different types of legionellosis: Pontiac fever and Legionnaires’ disease. Pontiac fever is a mild respiratory illness and Legionnaires’ disease is a type of pneumonia. Most of the time, legionellosis happens as a single event, but outbreaks involving large numbers of people have happened. Those who have a compromised immune system, who smoke, or who are 50 years or older are more likely to be affected by legionellosis.

How is it spread?

  • Legionella bacteria can be found in both natural and man-made water sources.

  • Legionella bacteria grow well in warm water (e.g., cooling towers, hot tubs, plumbing systems, hot water heaters, decorative fountains).

  • People become sick when they breathe in mist from a water source that has Legionella bacteria.

  • It cannot normally be spread from person to person.

What are the signs and symptoms?

Symptoms usually start two to 10 days after breathing in mist or water droplets that have Legionella bacteria

  • Muscle aches 

  • Headache 

  • Tiredness 

  • Loss of appetite 

  • Coughing

  • Fever

  • Diarrhea (occasionally)

Contact your doctor if you develop any symptoms.

What are the treatment options?

  • Treatment depends on whether the person has Pontiac fever or Legionnaires’ disease.

  • Pontiac fever requires supportive care only and will go away on its own.

  • Legionnaires’ disease requires treatment with antibiotics.

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