Legionnaire’s disease

Legionella – too important to ignore

The health and well-being of employees is paramount if a business is to be successful. A fully maintained water storage, heating, ventilation and air conditioning systems are an important part of this.

If any system is not performing as it should be or not cleaned or checked it can be a breeding ground for bacteria, in particular Legionella pneumophila which causes Legionnaire’s disease. Water systems must be properly maintained and regularly checked and inspected to make sure they are not aiding the growth of bacteria.


Legionnaires disease is a lung infection caught by inhaling small droplets of contaminated water suspended in the air. It is uncommon but potentially very serious and symptoms usually develop two to ten days after exposure to the legionella bacteria.

Early symptoms include headache, high fever of around 40C, chills, aches and coughing. Further symptoms range from chest pains and shortness of breath to vomiting and diarrhoea and psychological changes including confusion. The infection can lead to a number of complications including respiratory failure, septic shock and acute kidney failure and when not treated effectively and quickly, it may be fatal.

What harbours the bacteria?

LegionellaMost outbreaks have occurred in larger buildings due, perhaps, to the complex systems like air conditioning whichallow the bacteria to grow and spread. Two of the most common places to find Legionella are water storage systems and large central air conditioning systems.

People who control these systems are responsible for their upkeep and should always engage professionals to maintain the systems and check they are contaminant free.

The bacteria was discovered in 1976 when 221 attendees of an American Legion convention in Philadelphia came down with an illness of unknown origin. Symptoms include high fever, chills, aches and coughing. Thirty four of them died before the hotel’s air conditioning system was identified asthe source of spreading the disease.

Any water system, under the right conditions, could be a breeding ground for legionella bacteria to thrive in. Employers and landlords are duty bound to understand the risks and make sure properly qualified professionals service and maintain any systems. All systems require risk assessments and these need to be reviewed regularly.

Managing the risk

A primary method used to control the risk of Legionella in water storage systems is temperature control. The bacteria thrives at temperatures between 20 and 45 degrees Celsius. Below 20 degrees Celsius and the bacteria is dormant and anything over 50 degrees Celsius and the bacteria is killed.

Don’t let water stagnate. Water that is unused or allowed to be in the high risk temperature bracket means the bacteria will flourish. Professionals will ensure water cannot stagnate and keep the system clean with regular maintenance and if necessary, systems can be redesigned and modified to incorporate a sanitation feature. Water can be treated to control the growth of legionella or limit its ability to grow and water samples can be taken.


For more information on how to prevent Legionnaire’s disease and to see how we can help, please call us on  01223 881081 or contact us.