According to the Institution of Occupational Safety and Health or IOSH, there are about 5,000 cases of Legionnaire’s Disease reported annually in the United Kingdom. In another report released by the Health Protection Agency in 2009, out of the 345 cases reported, 47 percent was contracted in the patients' communities, 5 percent was contracted while in the hospital, eleven percent was contracted while travelling locally, and 37 percent while traveling abroad. Out of 345 cases, 12 percent of this resulted in death.


Legionnaire’s Disease is caused by the bacterium known as legionella which thrives in water. However, there have been reported cases where it has been known to grow on soil. Experts have identified more than 50 species of the bacterium with Legionella pneumophila being identified as among the most lethal to humans. This bacterium has a short lifespan, lasting up to 72 hours. However, when the conditions are right, the bacterium can multiply rapidly. Among these factors are temperature, nutrients in the water, and stagnant water flow.

Among the symptoms of Legionnaire’s Disease are high fever, headaches, muscle pains and chills and dry cough. Some patients report difficulty in breathing while others also suffer from diarrhoea, confusion and delirium.

There are two ways a person can contract Legionnaire’s Disease. The first and most common way is through the inhalation of water droplets contaminated with the legionella bacterium. The second and rarer way for a person to contract the disease is when a liquid contaminated with the bacterium enters the person's lung via his windpipe. Almost everyone is susceptible to the bacterium and the disease. However, there are groups which are at higher risk against the bacterium. This includes smokers, heavy drinkers, people aged 45 years old and above, patients with chronic respiratory or kidney illnesses, and those who have a weak immune system.

The bacterium can be found almost anywhere water-based systems are used as long as the aforementioned conditions for growth and multiplication are met.

This includes: