What is Legionella and How Can it be Prevented?
Legionella is a genus of pathogenic Gram-negative bacteria that causes legionellosis including Legionnaires’ disease and Pontiac fever. The bacteria can develop in stagnant water at temperatures between 20 and 50 degrees* Celsius.
Legionellosis is an infection that is caused by bacteria that live in small drops of water and moist conditions which are usually associated with water systems and pipes. When ingested the bacteria causes a pneumonia-type illness, Legionnaires’ disease, which can result in respiratory failure, and milder flu-like illness, Pontiac fever. It is important to carry out legionella water testing on a regular basis.
The most effective, non-chemical, and kinder to the environment, treatments to prevent Legionella include:
- Flush water pipes to reduce or remove instances of stagnation
- Maintain cold water temperatures below 20 degrees Celcius and hot water above 50 degrees Celsius
- Monitoring scale and sediment in the water
Hospitals and Medical Practices
Commercial and Government Buildings
Hotels and Hospitality
Sports Clubs, Swimming Pools, Spa and Gyms
Where is Legionella Found?
Legionella bacteria can be found in many different water systems. The bacteria live and grow in water systems at temperature of 20 to 50 degrees Celsius. This type of water is found in hot and cold-water plumbing systems, hot water tanks, air conditioning cooling towers, condensers of large air conditioning units, humidifiers and whirlpool spas. Cases of Legionellosis have been identified in the United Kingdom and worldwide.
At any age, people can develop Legionnaires’ disease, but the illness usually affects older people, particularly those who smoke, as these individuals have a greater likelihood of developing a respiratory illness. People at an increased risk for Legionnaires’ disease include those whose immune systems are suppressed by diseases such as lung disease, cancer, kidney failure requiring dialysis or diabetes. People who use medication that suppresses the immune system are also at risk. Infection occurs by aspiration of contaminated water or ice.
Legionella Risk Assessment
A legionella risk assessment should be reviewed every two years in an ideal scenario or where there is reason to suspect that is no longer valid such as:
- Where there have been changes to the use of the building
- Where there have been changes to the water system or its use
- Where new information about risk or control measures has become available
A Legionella and water risk assessment counts towards your compliance with the Health and Safety Executives Legionella approved code of practice and guidance document which is ACOP L8.
20 and 50 degrees* – source World Health Organization