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What is Legionella?

Legionella is a naturally occurring bacteria wide spread in nature. When the bacteria enter water systems in the built environment, conditions can often favour and encourage significant growth and reproduction to levels which can cause bacterial pneumonia and be fatal to humans. As a result legionella is considered as a biological hazard and is listed under the COSHH Regulations. This defines the need for a suitable risk assessment to cover water systems in the work place.

What is legionellosis?

Legionellosis is the name for a group of illnesses associated with legionella bacteria. There are three main illnesses caused by the bacteria

Legionniares desease

Pontiac Fever

Lochgoilhead Fever

All types of infection are caused by Legionella pneumophila, although Legionella micdadei is responsible for lochgoilhead ferver.

Are there different types of legionella bacteria?

Yes, there are over 40 different species of legionella bacteria. However, legionella pneumophila is considered the most dangerous as it causes about 90% of the cases of infection. Around 16 different sub groups of legionella pneumophila have been reported as the cause of infection. However, Legionella Pneumophila Serogroup 1 is the most associated with Legionnaires’ disease in the UK.

What is Legionnaires’ disease?

Legionnaires’ disease is a potentially fatal, bacterial pneumonia infection that is contracted by breathing in water droplets with an incubation period of 2-10 days with an average onset of 3-6 days.

An infectious dose is clearly linked to susceptibility, although it is considered to attack between 2 to 5% of those exposed. The average mortality rate is accepted to be anything between 15 and 20% of people infected.

Pontiac fever is a more common, but milder illness caused by the same bacteria. Pontiac fever is a flu like illness which usually last up to five days. No treatment is needed for pontiac fever other than paracetamol or ibuprofen for the minor fever and muscle aches. Pontiac Fever is often contracted but goes undiagnosed as the symptoms are so similar to the flu. Pontiac fever does not develop into pneumonia.

Loichgoilhead Fever is also caused by legionella bacteria. Like Pontiac fever, loichgoilhead fever is not usually fatal and will normally abate itself without treatment.

What is Pneumonia?

Pneumonia is frequently but not always due to infection that causes inflamation of the lungs. The infection may be bacterial, viral, fungal or parasitic. Symptoms may include fever, chills, cough with sputum production, chest pain, and shortness of breath.

Children and babies who develop pneumonia often do not have any specific signs of a chest infection but develop a fever, appear quite ill, and can become lethargic. Elderly people may also have few symptoms with pneumonia.

Some cases of pneumonia are contracted by breathing in small droplets that contain the organisms that can cause pneumonia. These droplets get into the air when a person infected with these germs coughs or sneezes. In other cases, pneumonia is caused when bacteria or viruses that are normally present in the mouth, throat, or nose inadvertently enter the lung.

Some types of pneumonia are known as atypical. These include infections caused by certain bacteria, such as Legionella pneumophila, Streptococcus pneumoniae, Mycoplasma pneumoniae and Chlamydophila pneumoniae (this is not an STD).

Mycoplasma pneumonia is a common in children and may be associated with non-respiratory problems, such as rashes, anaemia or meningitis.

If Pneumonia is diagnosed it is important to find out what form of the infection it could be.

Who is most susceptible to legionellosis?

The illness occurs more frequently in men than women at a ratio of around 3:1. It is thought that this may be a result of typical occupations, lifestyles and possibly lungs size. However, it usually affects middle-aged or elderly people and individuals with suppressed immune systems. Legionnaires’ disease is very uncommon under the age of 20 and whilst children can catch the disease it is very rare.

What is Legionella pneumophila?

Legionella pneumophila is the type of legionella species responsible for 90% of legionella outbreaks in the UK.

How do you get Legionnaires’ disease?

Legionnaires’ disease is contracted by inhaling small water droplets which can be suspended in the air known as aerosols. Aerosols containing the bacteria will pose a risk to susceptible individuals. Infection however, is clearly linked to susceptibility. Highly susceptible individuals may get infected even at relatively low doses. The HSE deem a domestic water system to be under control if legionella is maintained below 100cfu/l. There are particular controls for the NHS who have particularly susceptible individuals in there premises all the time.

How is Legionniares’ disease treated ?

If you were to contract Legionnaires’ disease it would need to be treated with antibiotics. Without treatement it can be fatal. Many antibiotics are highly effective against Legionella bacteria. The two most potent classes of antibiotic are the macrolides and the quinolones. Other agents that have been shown to be effective include tetracycline, doxycycline, and minocycline.

What are the symptoms?

The symptoms of Legionnaires’ disease, pontiac fever and loichgoilhead fever are all similar to the symptoms of very severe flu. As a result, legionellosis often goes undetected:

High temperature, feverishness and chills
Cough
Sputum
Muscle pains
Headache
Pneumonia
Diarrhoea
Signs of mental confusion

are all some of the symptoms experienced.

Is Legionnaires’ disease contagious?

Legionnaires’ disease is not contagious and cannot be passed from person to person. The disease is transmitted by inhaling the aerosol of an infected water supply, not by infected persons. Legionella is different from Swine Flu and SARS which are contagious.

Do I need a risk assessment?

A suitable legionella risk assessment is required to cover water systems in any commercial premise. This includes rented housing stock particularly where communal services are present.

How often should you update the legionella risk assessment ?

The Approved Code of Practice requires that legionella risk assessments be updated regularly (every two years at least) or when significant changes occur that may render the current risk assessment invalid.

How often should you review a risk assessment?

The legionella risk assessment should be updated at least every two years. However, where there are changes to the water systems or responsibility structure, the risk assessment will need to be updated. Further to this an annual review should be conducted to ensure the systems are being suitably managed.

Do Local Authorities and Housing Association, Estate Agents and Landlords need to Carryout Legionella Risk Assessments?

IN SHORT THE ANSWER IS YES! – Visit http://www.hse.gov.uk/services/localgovernment/faq.htm
All local authorities are required to carry out legionella risk assessments. However the HSE accept a more pragmatic approach will be required and even suggest that a generic risk assessment may be used where large residential housing stocks are involved. However, this will require careful judgement and Organisation should appoint specialist support to risk categorise stock to create the generic assessments. Further to the risk assessments annual condition reports will be required to ensure the efficacy of the generic assessments. Various precautionary tasks should also be considered to clearly demonstrate that the risk ratings are appropriate.

Do all work places need a legionella risk assessment?

The HSC’s, Approved Code of Practice applies to any undertaking involving a work activity and to premises controlled in connection with a trade, business or commercial enterprise or undertaking. Where water is used or stored which can be transmitted in an aerosol and then be inhaled, there will be a reasonably foreseeable risk of exposure to legionella bacteria. As a result if you have water on your site, you will need to carry out a Legionella risk assessment to identify the level of risk. Ask yourself, does the Health and Safety at work Act Apply to your situation? if the answer is yes, then you most definitely need a legionella risk assessment. Even in a brand new building!

What happens after the legionella risk assessment ?

If the legionella risk assessment identifys a low or negligible risk, you may not need to do anything else apart from review the risk assessment every two years. However if there is a foreseeable risk of legionella infection then a control scheme will be required to manage the risks. However, for a basic domestic system the control scheme need not be complicated.

Will I need to carry out a legionella risk assessment if I have a Health and Safety Risk Assessment?

A good health and safety risk assessment will normally define the requirement for a full legionella risk assessment to be conducted. The health and safety risk assessment will highlight all the likely health and safety risks in the workplace. However, the health and safety risk assessment will not normally actually assess the risks of legionella and it will not provide a site specific control scheme or schematics required to provide adequate cover for your organisation. A fully HSE L8 compliant risk assessment will still be needed in most cases.

What do I need to do after the legionella risk assessment is carried out?

If your legionella risk assessment identifies a low or negligible risk, then a simple review of the assessment will be required at least every 2 years. If a reasonably foreseeable risk is identified a programme for continual monitoring and control may be required and remedial actions may also be required to find an engineered solution to manage or eliminate the risk.

How can you control Legionella?

There are numerous measures that can be adopted to create water systems in the built environment that are hostile to the growth of legionella. Most traditionally, temperature is used to control legionella. Wherever possible, temperature should be the initial line of defence used to control legionella growth in a system.

Temperature control

Cold Water – If we can manage the cold water temperatures throughout the system to ensure that cold water is stored below 20°C and distributed to all outlets within two minutes of opening the tap below 20°C then the cold water circuit will not encourage bacterial growth including legionella growth.

Hot Water – Hot water should be stored at 60°C and distributed and supplied to all outlets above 50°C within 1 minute of operation.

Stagnation: Stagnation can be prevented by introducing routine flushing programmes and reducing the volumes of stored water.

Chemical control: At Watercare™ we see the use of chemicals as the last line of defence, and we will always explore the fundamental measures for control and management before embarking upon or recommending any chemical treatment programme for domestic systems.

Will I need to do any routine monitoring?

The control scheme and level of monitoring depends on the water systems and services located on your site. Typically, in a standard London based office space or building, with a basic domestic water system, a programme of routine temperature checks and 6 monthly and annual inspections will be required including an annual review. Further to this any infrequently used water services will need to be flushed on at least a weekly basis and any shower heads and spray taps should be cleaned and disinfected on a quarterly basis. Legionella monitoring will not normally be required in a typical office environment, however there are many circumstances where sampling is advocated for examples where temperatures cannot be controlled within the desired range. Furthermore, legionella sampling will demonstrate that the control scheme is working effectively and will provide employers with documented evidence of the quality of water at their sites.

Important! If you have cooling towers specialist routine monitoring will be required to reduce the risks going forward.

What temperature should my hot water heater or calorifiers be?

It is extremely important that the hot water heater or calorifier water heater is set to achieve a storage temperature of 60°C. Hot water should then be distributed to reach the outlets between 50-55°C within 1 minute of operation. Temperatures above 55°C will pose a risk of causing scalding injury and should be clearly labelled with caution hot water signs.

What temperatures should my cold water tanks and tap outlets be?

Cold water temperatures should typically be below the recommended 20°C guideline throughout. Cold water temperature should be recorded below 20°C and no more than 3°C rise on the incoming mains supply within two minutes of operation. However, please note that in some circumstances the incoming mains may be greater than 20°C particularly during the summer months of the year.

What do I do if I get a legionella positive result?

If you get a legionella positive result you should not panic! If legionella is identified in your system there are many measures that you can take to eradicate it. Measures such as thermal disinfections, temperature management and chemical disinfections can be used to clean your system. You do not need to report a legionella positive result to the Environmental Health or your Local Authority. If you obtain a legionella positive result and need assistance or support contact us today.

When do I need to disinfect the cold water storage tank?

A domestic cold water storage tank should be cleaned and disinfection when the systems is substantially altered, or after in depth maintenance or when an outbreak has occurred or is suspected. Visual inspection and sampling can also be used as a tool to decide when to clean a cold water storage tank. There is no legislation which defines that you must clean your cold water storage tanks on an annual basis.
However - If the tank is serving drinking water it should be cleaned at least once per year in line with the Drinking Water Inspectorate guidelines see, http://www.dwi.gov.uk/consumer/faq/dws.htm . All tanks should be inspected on at least a six monthly basis. If the tank does not serve drinking water there is no requirement to clean the tank on an annual basis.