legionella bacteria

Legionella – What Is It, And What Are The Dangers?

It is common knowledge that water systems can create an environment for bacteria to grow. Legionella is one of such bacteria that can grow on water. This bacteria is present worldwide and is usually found in aquatic environments, including premise plumbing. The presence of this bacteria in premise plumbing and even domestic water distribution systems makes it dangerous.  

Perhaps you have heard that this bacteria can cause severe disease and even lead to death. But do you know what legionella is and why it is dangerous? Here, we talked about Legionella,  how it can be contracted, and what danger it poses to people infested by it.

What Is Legionella?

Legionella is a bacteria found in water bodies like lakes, rivers, oceans, and groundwater.  This bacteria can be present in any water flow.  This is why the water you use in your house can be infested by legionella bacteria.

Having a professional  water treatment  is necessary to keep it at bay.  People in commercial and residential buildings are obligated to ensure the water systems are constantly clean to prevent the infection of legionella.

How do people contract Legionnaires’ disease?

Some ways people can contract legionnaires’ disease include:

  • Coming in contact with and inhaling water contaminated  with the bacteria. People can also  breathe in air containing droplets of water contaminated by the legionella bacteria.
  • Contaminated water systems.  If the water systems in commercial and residential buildings are contaminated with the legionella bacteria,  people who use the water can be exposed to it. Water systems like storage tanks, water heaters, hot tubs, tanks, and fountains can be contaminated.

Who can get infected by Legionella?

Although anybody exposed to legionella is at the risk of being infected by the bacteria,  healthy people are less likely to contract the bacteria if they are exposed to it. However,  there are some people who are more prone to contracting the bacteria. Some of them are:

  • People with underlying diseases like obstructive pulmonary disease and odor chronic lung disease.
  • Older people,  especially those who are 50 years and above
  • People who have smoked before and those who are currently smoking
  • People with weak immune systems
  •  Survivors of chronic diseases like kidney disease, diabetes and cancer.

What Are The Dangers of Legionella?

People who contact legionella are exposed to such dangers as:

Legionnaires’ disease

This is a respiratory disease caused by legionella. The bacteria affects the lungs of people who are exposed to it, causing them to experience a severe pneumonia. People who contract this disease usually experience symptoms like fever, shortness of breath, cough, headache,  confusion and muscle aches.

Some people also experience nausea and diarrhea. The symptoms can manifest after being exposed to the bacteria for at least 2 days and at most 14 days.  However,  there are cases where it manifests after a longer time.

Pontiac fever

Pontiac fever is similar to the flu but it is milder. It may not involve pulmonary discomforts.  When it does, it is usually nonfatal. People with pontiac fever often experience symptoms like muscle ache, loss of appetite, and fever. Affected people can experience these symptoms after a few hours of being exposed to the bacteria.

For some people, the symptoms can start manifesting after 4 days of being exposed. Pontiac fever may not last up to a week and can go away on its own.  Some people can take antibiotics to clear the bacteria from the body.

Prolonged ill health

One reason why legionella is dangerous is that legionellosis  can degenerate into more severe health issues if it is not treated immediately.  People who have underlying health conditions like  diabetes,  cancer,  and lung diseases can also experience fatal  health conditions if they are not treated immediately.


In cases where treatment is delayed and the patient’s immune system is weak, legionellosis can lead to death. Severe pneumonia complications can lead to multi-organ failure and, consequently, death.

Long term effects

After people who survived legionellosis have been discharged from the hospital, research has shown that they still suffer long-term effects of the disease. The study revealed that some people suffered neurological impairment and had difficulty with concentration. There are also cases where people experienced neuromuscular challenges. Some of the people were reported  to have experienced these symptoms for up to 17 months.

Some of the survivors reported experiencing respiratory challenges like breathlessness and cough even after being discharged from the hospital. Some of them experienced fatigue for up to one year after they have been treated. Some also experienced memory loss and post-traumatic stress disorder.

With early reports and proper treatments,  people who are infested by legionella can recover fully.  However,  neglect can lead to fatal outcomes.

What are legionella prevention measures?

There are many measures you can take to prevent the infection of Legionella.  Some of them are:

Constant monitoring, testing, and risk assessment

Monitoring your water constantly to ensure it is free of  bacteria like legionella is essential to keeping this bacteria at bay. Regular risk assessment is also essential to ensure that your  water is always safe and free of the bacteria. Using professionals to test your water will ensure you get the best results.

Always keeping your water clean

It is helpful to always keep your water clean. Ensure your water tank is properly closed and debris does not get in.

Flush your system

Before you move into a new building,  flush out the system and ensure it is properly cleaned.

Ensure your pipework is functioning properly

Always ensure your pipes are clean and not lined with  accumulated dirt as this can be a breeding ground for bacteria.  Any pipework that is not being used should be removed.


Legionella is a bacteria that lives in water. Coming in contact with legionella can lead to  legionellosis which includes pontiac fever and legionnaires’ disease. If not treated early and properly, this disease can lead to more severe health challenges,  and even death. Regular water monitoring, cleaning, and risk assessment will ensure the water remains clean and free of Legionella.