Legionnaires’ Disease

Below we aim to give a brief background to Legionnaires’ disease, the legislation surrounding legionella bacteria management, and what steps should be taken for legionella risk management.

What is Legionnaires’ Disease?

Legionnaires’ disease was first identified following a large outbreak of pneumonia among people who attended an American Legion Convention in Philadelphia in 1976.  A previously unrecognised bacterium was isolated from lung tissue samples, and subsequently named Legionella pneumophila.  It is normally contracted by inhaling Legionella bacteria deeply into the lungs, either from tiny droplets of water (aerosols), or in droplet nuclei (the particles left after the water has evaporated) that are contaminated with legionella.

What are the implications and disease impact?

Initial symptoms of Legionnaires’ disease include high fever, chills, headache and muscle pain.  Patient may develop a dry cough and most suffer difficulty with breathing.  About one third of patients infected also develop diarrhoea or vomiting and about half become confused or delirious.  Legionnaires’ disease can be treated effectively with appropriate antibiotics.  The incubation period is between 2-10 days (usually 3-6 days).  Not everyone exposed will develop symptoms of the disease and those that do not develop the ‘full blown’ disease may only present with a mild flu-like infection.  This is part of what makes Legionnaires’ disease so dangerous; many patients are initially diagnosed with flu.

On average, there are approximately 300-400 reported cases per year in the UK with approximately 12% fatalities, however this rate can be higher in a more susceptible population; for example, immunosuppressed patients or those with underlying disease.  These figures are known to be low due to the under-reporting factor associated with Legionnaires’ disease.  The initial symptoms are flu-like, and Legionnaires’ disease symptoms are similar to pneumonia.  At this stage, it is cheaper to treat unknown cases as pneumonia than it is to investigate the possibility of Legionnaires’ disease, without a cluster of cases to indicate an outbreak.  Health Protection England have given estimates as high as 10,000 cases per year as a real possibility.  Certain groups of people are known to be higher at risk of contracting Legionnaires’ disease; for example, men appear more susceptible than women, as do those over 45 years of age, smokers, alcoholics, diabetics and those with cancer or chronic respiratory or kidney disease.

Fees for intervention

The Health & Safety Executive introduced Fees for Intervention in 2012.  This is a scheme whereby businesses will be charged for the cost of a visit to a site where a ‘material breach’ has been discovered.  This includes a lack of legionella monitoring programme, a lack of risk assessment or appointed person to manage legionella risk, or signs of scale or other organic contamination in the water system.  This is charged at £124 for every hour the HSE spend on-site when they discover the material breach, and also time spent off-site writing reports.  It is clear therefore that it is more beneficial to contact ChemTech Consultancy to help manage your legionella risk before a breach occurs.

What is the law surrounding Legionella?

A brief history of the regulations surrounding Legionella.

2017 – New HSE Guidance Notes for Spa Pools

An excellent new guidance document for Spa Pool owners and managers has been published.  HSG282 ‘The Control of Legionella and Other Infectious Agents in Spa-Pool Systems’ helps those who manage and control such systems with their compliance with ACoP L8.


New ACoP L8 and Technical Guidance HSG274 documents released. Part two of the previous edition of the ACoP was removed and published separately as HSG274, covering evaporative cooling systems, hot and cold water systems, and other risk systems.

How does a Legionella Outbreak affect me?

The ACoP applies whenever water is stored or used in a way that may create a reasonably foreseeable risk of Legionellosis.  In particular it applies to the following plants:

  • Cooling tower systems
  • Evaporative condensers
  • Hot and cold water systems in non-domestic premises
  • Hot and cold water systems where the occupants are particularly susceptible (i.e. health/care premises)
  • Humidifiers and air washers, spa baths and pools
  • Other plant and systems containing water which is likely to exceed 20°C and which may release a spray or aerosol (i.e. a cloud of droplets and/or droplet nuclei) during operation or when being maintained.

Whilst this is not an exhaustive list, it does identify those systems which are most likely to cause infection. Consideration should also be given to other systems, which can release spray or aerosol in the range of 20-50°C during operation, maintenance and testing.

The scope of a Legionellosis Risk Assessment is defined in the ACoP L8:2013, paragraphs 28-47.

Landlords are also required to have a Legionella risk assessment in place with regards to the properties that they rent out to tenants for a lease lasting less than seven years.  Legionella is also a concern in properties that are lying vacant for any periods of time.

How we can help with Legionnaires’ Disease

ChemTech Consultancy carries out a full range of high quality risk assessment, cleaning and monitoring works.  As Scotland’s leading independent Legionella control specialist, we have clients in sectors such as:

  • Industrial Sites
  • Local Authorities
  • Care Home Groups
  • Housing Associations & Property Managers
  • Healthcare Premises
  • Leisure Premises
  • NHS Trusts
  • Commercial Premises
  • Letting Agents & Private Landlords

ChemTech Consultancy’s highly trained team of water hygiene technicians can carry out a wide variety of work to ensure you comply with your responsibilities regarding legionella risk control and management.  Make an enquiry today to find out how we could meet your needs.

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