I recently collated the top 4 questions from customers this year and decided to write an article about them…

 

 

Samples where Legionella is detected means someone could catch Legionnaires Disease?

There are multiple species, some have not been found to be pathogenic whereas some are less so. Microbiological water sample results are often categorised by species such as L. pneumophila serotype 1, serotype 2 – 14, Legionella Species and Total Legionella Species.

Although the AS 3666 (the standard for cooling tower management) includes a safe level for Legionella detection and an appropriate response, there is no such “safe level” described in domestic water systems at present and as per Queensland Health request, all species and CFU numbers need to be reported.

 

Are cooling towers the most likely cause Legionnaires Disease?

Potable water sources can just as often be a source of Legionella, a lot of the time the media report outbreaks of cooling towers as they tend to affect multiple people in densely populated areas.

Believe it or not, there is a form of Legionnaires Disease which can be transmitted through potting-mixture and don’t forget to drain the garden hose after you use it!

 

Legionnaires Disease is only a problem for high-risk individuals such as elderly, smokers or immunocompromised?

Although those groups are of an increased risk it has been estimated that 25% of cases are of people under 50-years-old.

Like how the flu can affect some people severely, we cannot always predict how our bodies will react to infections.

Is it worth gambling with your health, even if you think you are otherwise healthy?

 

Is Legionella only a problem in stagnant water or old buildings?

Sometimes even with an effective maintenance program including flushing and cleaning, Legionella can persist and it’s worth noting the importance of monitoring sampling.

Poor plumbing structures such as dead-legs can contribute to the growth of bacteria but sometimes levels of water disinfectants can dissipate at distal locations.

During warmer months the water temperature can easily reach 30℃, at which point most bacterial growth will peak.