What are Legionella and Pseudomonas?
Legionella bacteria can cause Legionnaires’ disease, a difficult-to-treat form of pneumonia if inhaled in water droplets. Pseudomonas aeruginosa, another category of a pathogen, can infect almost any part of the body from the skin to the central nervous system. The threat from these organisms is very real. Between 3,700 and 4,000 P. aeruginosa infections are reported to the Health Protection Agency every year, and the fatality rate for hospital-acquired Legionnaires’ disease is close to 50% The UK has strong regulatory frameworks governing the design and operation of water supply systems. The HSE document Legionnaires’ disease: The control of legionella in water systems is the approved code of practice in the UK. While Legionella bacteria enter the water system of a building from the external supply, Pseudomonas aeruginosa is far more opportunistic. It can survive away from a water source for several hours and can enter water systems via outlets within the building, such as taps and shower heads, and colonise the pipework close to these fittings.