Reducing the risk of Legionnaires' disease

Many common aquatic bacteria like Legionella pneumophila are able to colonize man-made water systems. Poorly maintained systems or those that are seldom used provide ideal sites for growth and often also provide the means for aerosolizing the organism. Compounds leached from construction materials and the by-products of other organisms can be used as food by the Legionellaceae and can thus aid their growth. Keeping water systems clean and well serviced, keeping hot water at or above, and cold water below, recommended temperatures and additionally in cooling towers maintaining the required levels of biocide, will reduce or prevent the growth of legionellas. To be certain that the control measures are successful microbiological and chemical monitoring should be done. The results of this and the maintenance work undertaken should be kept in a log so that failures in treatment can be quickly seen and remedial action taken before any risk of infection arises. Adhering to these simple guidelines will go a long way to removing the risk of infection and will also provide systems that are more efficient and thus cheaper to run.