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PLUMBING CONNECTION
WINTER 2015
THE BACTERIA PUZZLE
B
acteria are an inevitable part of life. Many are
benign or even beneficial to humans, but pathogenic
bacteria are harmful and even deadly. Most
healthy humans can easily fight these off, but people with
compromised immune systems – those who are elderly, ill,
or injured – are susceptible to bacterial infections that can
prove fatal. Two of the most common pathogenic bacteria
– legionella and pseudomonas – gain access and spread
through hospitals and aged care facilities via the water
system.
Legionella and pseudomonas are a worldwide problem
and yet there is a marked difference in the level of defences
throughout the world. Leading the charge is certainly the
UK and Europe. The UK has a standard in place for legionella
control in health and aged care facilities and is possibly the
largest market for temperature controlled outlets.
One of the largest producers of these outlets is Australian
– Reliance Worldwide supplies about a third of the British
demand – and yet Australia is much less advanced in
defending against bacterial infections in water supplies.
Peter Flynn, Export Manager for Reliance Worldwide,
estimates we’re about 10 years behind the UK.
“In the UK, the standard used to allow six metres of tepid
water. Then it went to one metre, then it went to ‘we prefer
you to put the thermostatic in the tap’,” Peter recalls. “I
don’t even think we have a distance in our plumbing code,
you can do anything you like.”
There is hope though.
“If you’d asked me twelve months ago, I would’ve said the
United States was not all that interested in legionella,” Peter
says. “Since about November last year, it’s now a hot topic.”
(For more discussion on Legionnaires control in the
States, read Matthew Freije’s article on page 42).
Reliance Worldwide is now seeing increased demand from
the United States for thermostatic controls. When they’ll
see demand from their home country is hard to tell.
JUST ONE PART OF THE PUZZLE
One of the reasons there is a lack of movement on
infection control is the sheer complexity of the solution.
There is no one way to tackle bacterial infections; instead a
myriad of tactics must be employed.
To explore the problem and the various solutions, we
spoke to four experts in water supply. The first was Peter,
mentioned above; next were Steve Gamble and Kevin Peel,
Senior Product Manager and Associate Director of New
Product Development respectively, from Rada Controls.
Lastly, we spoke to hydraulic project engineer Antonio Lo
Monte from Wood & Grieve Engineers.
THE PROBLEM
Before we can look at a solution, however, we must identify
the problem: legionella and pseudomonas. Through Rada’s
research into developing new, low infection-risk outlets,
Steve and Kevin became very familiar with both bacteria –
LEGIONELLA AND PSEUDOMONAS BACTERIA HAVE A PRESENCE IN HOSPITALS AND AGED CARE FACILITIES AROUND
THE WORLD.
KATE JORDAN
LOOKS AT WHAT NEEDS TO BE DONE TO CONTROL AND PREVENT FURTHER INFECTIONS.
INFECTION CONTROL
THE EFFECT OF TEMPERATURE ON LEGIONELLA
Temperature Range Effect on Legionella
70-80
Disinfection range
66
Legionella will die in 2 minutes
60
Legionella will die in 32 minutes
55
Legionella will die in 5-6 hours
50-55
Legionella can survive but do not multiply
20-50
Legionella growth range
Below 20
Legionella can survive but are dormant