What is Legionella?

Legionella is a type of bacteria that can cause serious health problems, including a severe form of pneumonia known as Legionnaires’ disease. This microscopic organism thrives in water systems and can pose significant risks to public health if not properly managed. In this blog post, we’ll explore what Legionella is, where it’s found, and how to prevent its growth in your building’s water systems.

The Origin of Legionella

Legionella bacteria were first identified in 1976 following an outbreak at an American Legion convention in Philadelphia, hence the name “Legionnaires’ disease.” The bacteria naturally occur in freshwater environments like lakes and streams, but they become a health concern when they multiply in man-made water systems.

Where Does Legionella Grow?

Legionella bacteria thrive in warm, stagnant water. Common breeding grounds include:

• Hot and cold water systems
• Spas and whirlpool baths
• Large air conditioning systems
• Fountains and water features
• Fire sprinkler systems
• Humidifiers

These bacteria can quickly colonise and multiply in water temperatures between 20°C and 45°C (68°F to 113°F), with the optimal growth occurring around 35°C to 37°C (95°F to 98.6°F).

Health Risks Associated with Legionella

Legionella bacteria can cause two main types of infections:

Legionnaires’ disease: A severe form of pneumonia that can be life-threatening, especially for older adults, smokers, and people with weakened immune systems or chronic lung diseases.

Pontiac fever: A milder illness that causes flu-like symptoms but doesn’t progress to pneumonia.

People typically contract these infections by inhaling small water droplets contaminated with Legionella bacteria. This can happen through air conditioning systems, showers, or other sources that create water mist.

Preventing Legionella Growth

To minimise the risk of Legionella growth in your building’s water systems:

Maintain water temperatures outside the ideal growth range (keep cold water below 20°C and hot water above 50°C).

• Regularly clean and disinfect water systems.
• Prevent water stagnation by regularly flushing unused taps and showers.
• Ensure proper water treatment, including the use of biocides when appropriate.
• Conduct regular risk assessments and water testing.
• Keep your water system well-maintained, repairing any faults promptly.
• The Importance of Legionella Risk Assessments

Regular Legionella risk assessments are crucial for identifying potential hazards in your water systems. These assessments help you develop an effective water management plan to prevent Legionella growth and protect the health of building occupants.

 

Understanding what Legionella is and how it spreads is the first step in preventing outbreaks. By implementing proper water management practices and conducting regular risk assessments, you can significantly reduce the risk of Legionella growth in your building’s water systems. Remember, prevention is always better than cure when it comes to protecting public health.

If you’re concerned about Legionella risks in your commercial building, consider scheduling a professional Legionella risk assessment. It’s an essential step in ensuring the safety of your water systems and the health of your building’s occupants.