Introduction
Legionella Background
Legionnaires’ disease, also known as Legionellosis, is a type of pneumonia, which can potentially be fatal although it varies in severity from case to case. Legionella bacteria can also cause other, less harmful illnesses such as Pontiac fever and Lochgoilhead fever, which can affect all people.
Route of Infection
The main route of infection is primarily through inhalation of aerosols, fine droplets and mists. However, it can also be contracted by choking on contaminated water.
How does Legionella Grow?
Legionnaires’ disease, also known as Legionellosis, is a type of pneumonia, which can potentially be fatal although it varies in severity from case to case. Legionella bacteria can also cause other, less harmful illnesses such as Pontiac fever and Lochgoilhead fever, which can affect all people.
The following areas encourage legionella growth –
Stagnation
Areas where there is little to no flow of water. E.g. garden taps or school showers.
Temperature
Temperatures that promote legionella grow include 20-45°C, and often up to 55°C.
Materials
Materials that encourage growth such as steel, rubber, lead pipework.
Conditions
Poor water system conditions promote legionella growth. Conditions might include limescale, sediment, rust, sludge, algae, and sunlight.
Management
Poor management is one of the leading causes of legionella growth. Lack of training, understanding and competency often leads to non-compliance and increased risk of growth.
100°C
There will be no viable legionella.
60°C
Legionella will not multiply and will die in time.
20-50°C
Legionella will multiply.
Less than 20°C
Legionella will remain dormant.
Legionella & Temperatures
Temperatures that promote legionella growth include the ranges of 20-45°C. It is for this reason that temperatures between 20-50°C should be avoided to minimise the risk of legionella proliferation and potential exposure.
Legionella Symptoms & Facts
The following list of symptoms and facts help us to understand legionella in numbers. Susceptible people typically include: Over 50, heavy smoker, alcohol, no exercise, illness with respiratory or kidney complaints and cancer.
Symptoms
High fever, chills, headaches, severe muscular aches, dry non-productive cough, breathlessness, diarrhoea, vomiting, confusion/delirium
Incubation Period
2-10 days.
Causes
Often you have come into contact with a water system that contains legionella bacteria. This may be at home, at work, or in a public area.
Treatment
Antibiotics are typically prescribed to help ease the symptoms of legionnaires disease.
Diagnosis
A urine sample will be taken to determine if there is a detection of legionella bacteria presence.
Incidence & Mortality Rate
388 cases per year in the UK. The mortality rate for those who contract legionnaires disease is 12% and 30% in vulnerable persons.