So what is Legionnaires’ disease? The HSE states that “Legionellosis is the collective name given to the pneumonia-like illness caused by legionella bacteria. This includes the most serious legionnaires’ disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever. Legionnaires’ disease is a potentially fatal form of pneumonia and everyone is susceptible to infection”. (http://www.hse.gov.uk/legionnaires/what-is.htm 11)
The disease is usually contracted by a person inhaling the legionella bacteria deep into the lowest part of the lungs. The bacterial organism is only able to enter the body when it is contained in a particle of less than 3 micro meters in diameter. Particles this small are able to suspend themselves in the air and travel great distances. The scientific term for these suspended particles is an aerosol. We can easily create aerosol particles using water in a variety of ways, some everyday examples are found in domestic hot and cold water systems, rainfall, hoses, and air conditioning units. The leigoinella bacterium itself is very widespread in nature and is found living in water, however only certain strains can harm humans. The typical symptoms of the disease are mild headaches, fever, muscular pain, a persistent cough, vomiting and diarrhoea. About half of the people who contract the disease may experience a change in their mental state becoming confused and disorientated. (blogs.independent.co.uk 4)
The disease is transmitted via purpose built water systems. In the UK very