Questions and Answers to keep you informed on legionella.

  1. Q) What legislation is in place with regards to legionella control?
  2. A) There is government legislation in regards to legionella control, and the following may apply to you:
  1. Q) What do I need to implement in order to comply with legislation?
  2. A) Employers and staff who hold responsibility for the premises (and the people within it) must prepare a written scheme (also known as an action plan). This action plan is designed to control the risk and prevent legionella spreading in their systems. This action plan, must on a regular basis, be monitored to ensure it remains effective. Records must be kept of the action taken, so that if there were ever any questions on how your premises controls legionella, you have evidence to prove you are taking action. You must carry out a legionella risk assessment (this is a service offered by Managed Water Services).  Appoint a legionella manager so that they can regularly monitor the systems and can also arrange for work to take place when and if it is needed.  It is important for anyone in your organisation who is responsible to be suitably trained and competent.


  1. Q) How do I know that I comply with legislation?
  2. A) On Managed Water Service’s Information Reference Centrethere is a document called ACOP L8 (this stands for Approved Code of Practice). It is a Health and Safety Commission guidance document which covers the control of legionella bacteria. Alternative methods to ACOP L8 are available; however, if you are caught breaching Health and Safety Law, you will need to have shown that you have complied with the regulations.


  1. Q) What exactly is Legionnaires’ disease and how does it affect me?
  2. A) Legionnaires’ disease is a pneumonia-like disease that has an approximate 12% fatality rate. Symptoms include: Muscle Pains, high temperature fevers and chills, dry cough, headaches that can lead to pneumonia and diarrhoea and signs of mental confusion.


  1. Q) How does someone contract Legionnaires’ disease?
  2. A) Legionnaires’ disease is caused by Legionella bacterium, a bacterium that occurs in the natural environment.  When this bacterium is released in an aerosol, a shower or a spray tap for instance, it spreads out into the atmosphere and can travel a significant distance. If a person comes into contact with the infected aerosol and it is breathed in to the lungs then it can cause Legionnaires’ disease.


  1. Q) How did Legionnaires’ disease get its name?

In Philadelphia in 1976 a large outbreak of a pneumonia type illness was apparent among people that had attended an American Legion Convention in the city. After sampling of lung tissues an unrecognised bacterium was found and subsequently called “Legionella Pneumophila” and the disease thus called “Legionnaires’ disease.”


  1. Q) What is the treatment available for Legionnaires’ disease?
  2. A) Most cases of Legionnaires’ disease are treated in a hospital; however, appropriate antibiotics are an effective way to treat the disease.


  1. Q) What are the chances of me contracting Legionnaires’ disease?
  2. A) According to the uk reports there are approximately 450 – 500 cases of Legionnaires’ disease in the UK each year.  By flushing systems regularly, especially when you have been away on holiday, the chances are low that you will contract Legionnaires’ disease at your home.  There are groups of people that are more susceptible than others; Men are more susceptible than women, those over 45 years are more susceptible, those with an underlying illness or addiction will also be more susceptible.


  1. Q) How is Legionnaires’ disease diagnosed?
  2. A) Legionnaires’ disease is diagnosed with a combination of tests, this can include mucus from the patient, a bronchoscopy or a by having a closer look at the lung tissue. Tests can also be used to measure the amount of antibodies in the blood, and also tests using the patient’s urine can measure specific antigens.


  1. Q) Are there other diseases that legionella bacterium can cause?
  2. A) Legionella bacterium can also cause Pontiac fever and Lochgolihead fever, both flu like diseases. Pontiac fever has an incubation period of 2-3 days whereas Lochgolihead fever usually has an incubation period of 9 days.


  1. Q) So where exactly does legionella bacteria come from?
  2. A) Legionella bacteria are found in natural water environments such as lakes, rivers and reservoirs; however, these are usually in low numbers and so are not dangerous to humans. Legionella bacteria grow under the right conditions: temperatures between 20-45˚C, an available food source e.g. biofilm, rust, algae and lime scale.  Low flow or stagnant water will also help the bacteria grow to large numbers.


  1. Q) So how can we hinder the growth of legionella bacteria?
  2. A) Legionella bacteria thrives between 20˚C and 45˚C, they are dormant below 20˚C and are being killed off at 60˚C. Temperature is the primary method of controlling legionella growth in our water systems although other methods using chemicals are also widely used.


by Managed Water Services