Legionella - Facts & Figures

What is Legionnaires' Disease

Legionnaires' Disease is a type of pneumonia. Legionella are natural aquatic bacteria occurring widely in the natural aquatic environment but most frequently in water at temperatures between 20°C and 50°C.

They have been isolated from rivers, lakes, ponds, thermally polluted waters, mud, natural thermal ponds and even on the canopy of tropical rain forests.

Legionnaires disease is a disease caused by the organism LEGIONELLA PNEUMOPHILA, which is found naturally in water and soil where it is normally harmless. However, when it gets the right conditions of temperature, nutrient supply and pH, it multiplies rapidly, and if there is aerosol formation and a susceptible population, are all the ingredients are in place for an outbreak.

The term "Legionnaires disease" was first coined to describe an explosive common source outbreak of pneumonia caused by an unknown agent afflicting persons attending an American Legion Convention in Philadelphia in July 1976. Of 192 diagnosed cases, 20 were fatal. Examinations of lung tissue from some of the fatal cases demonstrated the presence of a previously unknown organism which was eventually called LEGIONELLA PNEUMOPHILA. Although there are at least 44 species of legionellae, L. Pneumophila is by far the most important human pathogen.

Legionnaires Disease mainly affects adults, with men being more at risk than women. The greatest incidence of disease is in men over 40 years of age who also smoke. Persons who are immuno-compromised or suffering from respiratory disorders are also at higher risk. Infection is by inhalation of contaminated water droplets. If antibiotics are administered soon after diagnosis, significant mortality reductions can result.

What Systems do Legionella Colonise?

Sources of outbreaks have been traced to:-

  • Hot and cold water systems
  • Cooling towers
  • Spa baths
  • Oil/water emulsions used for lubricating lathes
  • Misting devices
  • Decorative fountains and water features
  • Dentistry tools
  • TMV's (thermostatic mixing valves)

...more Information, click the links below.


For More Information Contact:

EMS Pathology Management
iCon Environmental Innovation Centre, Eastern Way, Daventry, NN11 0QB
Tel: 01327 844848
FAX: 01327 844849
Internet: technical@legionnaires-disease.com