Legionnaires' Disease is Not Spread From Person to Person

Updated: Nov 16, 2018

Legionnaires' Disease Can Be Deadly, But It Is Not Spread From Person to Person

As a team, we get questions constantly asking about Legionnaires' Disease and how it can be contracted.

After Legionella grows and multiplies in a building water system, water containing Legionella then has to spread in droplets small enough for people to breathe in. People can get Legionnaires’ disease or Pontiac fever when they breathe in small droplets of water in the air that contain the bacteria.

Less commonly, people can get sick by aspiration of drinking water containing Legionella. This happens when water accidentally goes into the lungs while drinking. People at increased risk of aspiration include those with swallowing difficulties. In general, people do not spread Legionnaires’ disease and Pontiac fever to other people. However, this may be possible under rare circumstances.

Talk to your doctor or local health department if:

• You believe you were exposed to Legionella bacteria.
• and
• You develop symptoms, such as fever, cough, chills, or muscle aches.

Most healthy people exposed to Legionella do not get sick. People at increased risk of getting sick are:

• People 50 years or older
• Current or former smokers
• People with a chronic lung disease (like chronic obstructive pulmonary disease or emphysema)
• People with weak immune systems or who take drugs that weaken the immune system (like after a transplant operation or chemotherapy)
• People with cancer
• People with underlying illnesses such as diabetes, kidney failure, or liver failure

Your local health department can determine whether to investigate. It is always a good idea to call them if you have been diagnosed. Be sure to mention if you spent any nights away from home in the last 10 days.