What is legionellosis & legionnaires disease?

Legionnaires’ disease is a

potentially fatal, multi-system respiratory illness, accompanied

by pneumonia. It attacks 2 to 5% of those exposed (representative

of those most susceptible).

The average mortality rate is approximately 15 to 20%.

It incubates in human hosts within 2 to 10 days of exposure and will not abate without medication. When diagnosed and treated early enough, the disease responds well to the antibiotics.

Legionellosis is the collective term used to cover a group of diseases caused by legionella bacteria.

Did you know Pontiac fever is a more common but milder illness caused by the same bacteria. Pontiac fever is a flu like illness which usually only lasts a few 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.

Could you have caught Pontiac Fever without knowing ?

Another illness Loichgoilhead Fever is also caused by legionella bacteria. Like Pontiac fever, loichgoilhead fever is not usually fatal and therefore often goes un reported.

Legionnaires' disease - what are the symptoms?

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

Where does it come from?

The Legionella bacteria that causes Legionnaires' disease is widespread in nature. It mainly lives in water, for example ponds, rivers, lakes and reservoirs where it does not usually cause problems. Infectious outbreaks occur from purpose-built water systems where temperatures are warm enough to encourage growth of the bacteria, e.g. in cooling towers, evaporative condensers, whirlpool spas (Jacuzzis) and importantly in domestic water system found in almost every work place. It is this that give rise for the need to set specific guidelines and legislation for the control of Legionnaires' disease in the work place.

The most documented community outbreaks in the UK have been linked to installations such as cooling towers or evaporative condensers that can spread droplets of water over a wide area and thus infect a large number of people at one time. However, it should be noted that the majority of Legionella infections reported are actually related to basic domestic water systems located in most buildings  where suitable areas for the bacterial growth and proliferation have developed.