How do I reduce the risk?

Try to avoid installing misting machines in your home or office. They may offer a certain degree of comfort, but they may also offer Legionella. It would be a good idea to stay clear of them at shopping malls as well.

Keep your water tanks clean. Legionella are usually found in tanks that are coated with sludge and slime, and will usually live as layers of scum or as parasites of amoebae. Deny them these privileges and you will reduce the risk of these organisms breeding in your water.

If you are running a hospital, regularly monitor the water supply and take corrective action before anything happens – not after! In the event of an outbreak or isolation of the organism, remember to follow up on your monitoring.

Keep your hot water hot – that means above 70 degrees Celsius. Cold water storage and distribution temperatures should be kept below 20 degrees Celsius.

Chlorination of water sources can wipe out Legionella – but only if the concentration is two parts per million (ppm) or greater. Be warned, however, that studies have shown that the organism will grow in the water once again within two weeks of disinfection. Also, some studies have indicated that the organism may survive chlorination with the help of amoebae, some of which can tolerate high levels of chlorine.

Ozonation (0.79mg/litre or greater) of a potable water supply may be useful in eradicating Legionella . This would be more practical for large buildings than for households, however.

Stay healthy. Avoid smoking – smokers have the highest incidence of coming down with Legionnaires’ Disease – and engaging in activities that could threaten your health. If you are immunocompromised, stay away from things that can generate aerosols such as fountains, whirlpool spas and misting devices. See a doctor if you are sick, and if you come down with pneumonia, make sure they screen you for Legionella. Under no circumstances should you play doctor and prescribe yourself antibiotics. Many of them will not work against this organism, and you may be encouraging antibiotics resistance.