At least 9,000 people catch Legionnaires’ disease every year. This figure is higher than official statistics because many sufferers are misdiagnosed as the symptoms can be very similar to flu. It is fatal in 12 per cent of all cases, and in 50 per cent of cases among the elderly and infirm.

Source: B&ES – UK’s leading professional body for building engineering services contractors

 

Legionnaires disease is rare in the UK, but in 2010 there were still 359 reported cases of Legionnaires’ disease in England and Wales and to us, that’s 359 too many.

We’ll take it from the top, with a complete lowdown on Legionnaires’ disease:

 

  • What is it?

  • What systems are at risk and where is it commonly found

  • Medical aspects of the disease

  • The laws behind it

  • Engineering and management controls

  • Inspections and prevention tips

 

What is Legionnaires’ disease?

It is a lung infection caused by inhaling small droplets of Legionnaires contaminated water, but cannot be contracted from drinking contaminated water, contrary to popular believe. It cannot be passed from one person to another.

Everyone is potentially at risk to infection, but certain individuals are at higher risk:

 

  • People over 45

  • Smokers

  • Heavy drinkers

  • Sufferers from chronic respiratory or kidney disease

  • People with impaired immune systems

 

It was first discovered when an outbreak of pneumonia occurred in members of the American Legion after attending a conference at a hotel in Philadelphia. It was revealed to have been from a bacterial names Legionella Pneumophila, but since then a number of new species have been discovered.

Where can it be found, and what is at risk?

Legionella bacteria is common is natural water courses; anything from rivers, ponds, to streams. Since it is a naturally occurring bacteria, it is easy for it to transfer and grow in other water systems.

But what makes it tick? Legionella can survive in low temperatures, although it thrives at temperatures between 20-45 °C as long as the conditions are right. The ‘right’ conditions being something is packed with nutrients, i.e; rust, sludge, scale algae and other such bacteria.

Systems most at risk:

 

  • Air Conditioning Units

  • Wet Cooling Systems

  • Hot & Cold Water Systems

  • Hot Tubs

  • Showers

 

These all have the potential to create an aerosol and spread the disease around, especially in your workplace.

 

Medical Aspects/Symptoms

Currently, there are around 400-450 cases per year in the UK, with a mortality rate of 12%. Statistics show that males are more at risk to the disease, coupled with heavy smoking, alcohol, lack of exercise and immunodeficiency.

The incubation period for Legionnaires’ disease is 2-10 days and the symptoms can include:

 

  • High fever

  • Chills

  • Headaches

  • Muscular aches

  • Cough

  • Breathlessness

  • Diarrhoea

  • Vomiting

 

The law

There are several laws that you should know about, with regards to Legionnaires’ Disease and water safety:

 

 

Controlling legionella

There are ways you can control and prevent a legionella outbreak – some of them are from an engineering perspective, whilst others are simple managerial tasks.

Engineering controls:

 

  • Consider fitting mains water supplies, other than water tank storage

  • Adhere to Water Supply (Water Fittings) Regulations (Read the regulations)

  • Fit appropriate Backflow prevention (More info on this)

  • Ensure all stored water is clean, covered up and well insulated

  • Ensure that water cannot stagnate

 

Management Controls:

 

  • Monitor your systems regularly

  • Risk Assessment

  • Check your temperature control programmes

  • Flush any outlets that are not often used (these should be done every week – try not to create an aerosol, especially with showers)

With the right knowledge and proper precautions, it should be easy to keep legionnaires’ disease at bay. If you’re looking to get your premises tested for legionella traces, make sure you get it done by a fully accredited legionella specialist

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