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Legionella, a waterborne bacterium that causes Legionnaires’ disease, has been part of corporate consciousness for several decades now. There is a directive requiring legionella risk assessments to be done regularly on water systems as individuals who have inhaled contaminated water droplets may develop the potentially fatal lung disease.

It is actually possible to be exposed to legionella without getting sick. Healthy people generally have high immunity and wouldn’t be affected by exposure. However, even a healthy individual may succumb when directly exposed to high concentrations of the bacteria.

Legionella-contaminated water systems can cause significant damage to both life and reputation, hence the need to ensure that quality control is exercised in maintaining the water services of a facility.

There are ways to manage legionella risk; most of them involve water system maintenance.

  • Correct control of water temperature. Hot water should be stored at 60 degrees Celsius to all reach outlets at higher than 50 degrees Celsius while cold water should be kept cold at lower than 20 degrees Celsius.
  • Prevention of stagnant water conditions. A facility must maintain water turnover to keep the supply fresh.
  • Regular cleaning or treatment. Water systems, including the outlets, should be kept free of corrosion, dirt, or scale.

Although the United Kingdom has considerably fewer hospitalised cases of Legionnaires’ disease than the United States, legionella is still a valid cause for worry. For instance, outbreak investigations have reported both low and high levels of the bacteria in water samples from cooling towers. The implementation of cautionary measures is but prudent, especially in the case of hospitals and other healthcare facilities such as dental clinics, birthing centres, and nursing homes. It would be horribly ironic that patients would be infected by legionella in a place where they were hoping to have their health concerns addressed. For sure, not only does regular risk assessment protect those who use the water system, it also protects the facility from liability.

Legionella Risk Assessment may be easily done by sending out for test kits. A pack normally consists of one or more sterile bottles plus detailed instructions for gathering water samples. The process of determining the presence of legionella ordinarily takes about ten days, during which time the water samples are incubated to check for legionella growth. If the bacterium is present, the facility manager is alerted of the contamination. When a concentration of the bacteria is detected, the recommended course of action is to investigate by reviewing the water treatment program and taking remedial action by implementing disinfecting measures. After this, the water is to be retested every three to seven days until the results show up clear. High levels of contamination usually call for the immediate decontamination of the entire system.

Water system maintenance is essential to discourage legionella from occurring in the water of hospitals and health care facilities; however, your best bet for controlling the risk and ensuring safety is to regularly test for its presence.

+Duncan Hollis