How Does Legionnaires’ Disease Develop?

Legionnaires' disease Legionnaires' (Legionellosis) is caused by Legionella Pneumophila, a bacterium usually found in streams, rivers and lakes.

Legionnaires' Disease is a serious form of the Legionellosis infection. Symptoms include chill
s, fever, a cough, tiredness and fatigue, headache and muscle ache and decreased appetite. Distinguishing Legionnaires' Disease can be difficult, as chest scans and X-rays taken from patients can often present as pneumonia. Additional tests will be required for a patient to be firmly diagnosed with Legionnaire’s Disease.

Pontiac Fever, which is a milder form of Legionellosis does not include pneumonia-loke symptoms. Symptoms include muscle ache and fever. Patients suffering frolegionairesm Pontiac Fever typically recover within 2-5 days with no need for medical treatment. The onset of Pontiac fever typically occurs within 2 hours and up to 2 days following exposure and Legionnaires' Disease within 2-10 days of exposure.

Hows does Legionnaires' Disease Grow?

If conditions are favourable, the bacteria may grow increasing the risks of Legionnaires’ disease and it is therefore important to control the risks by introducing appropriate measures.

Where is Legionnaires' Disease found?

The bacterium Legionella and related bacteria are common in natural water sources such as rivers, lakes and reservoirs, but usually in low numbers. They may also be found in purpose-built water systems such as cooling towers, evaporative condensers, hot and cold water systems and spa pools.

Legionnaires’ disease is caused by Legionella bacteria infecting a person’s lungs. It's usually caught by breathing in small droplets of contaminated water. The infection isn't contagious and can't be spread directly from person to person.

Large buildings, such as hotels, hospitalslegionaires 2, museums and office blocks, are more vulnerable to Legionella contamination because they have larger, more complex water supply systems in which the bacteria can quickly spread.

Legionella bacteria can grow and reproduce in a water. Conditions which cause the bacteria to grow rapidly are;

  • a water temperature of 20-45C (68-113F)
  • impurities in the water that the bacteria can use for food – such as rust, algae and limescale

Although rare, Legionnaires' disease has also come from contaminated showers, sprinkler systems and spas. This is why Water Hygiene Service’s monitoring work is extremely important in the fight against outbreaks of Legionella.

Legionella Monitoring 

Our monitoring work includes tasks such as;

  • weekly flushing of little-used outlets
  • monthly temperature test results of representative outlets
  • quarterly descaling of shower heads and spray taps
  • annual inspection of calorifier
  • sannual water storage tank inspection
  • Four-monthly legionella risk assessment review.

Contact us today to discuss any upcoming work you have and for more information on water safety and Legionella prevention.