Legionella

Recap and UpdateRecap and Update

Overview

� What is legionella bacteria?

� How does it affect us?

� How do we control it?� How do we control it?

� Case Studies

� HSE 5 year study results

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�What is legionella bacteria?

• A rod shaped bacteria occurring naturally in water

• 40 or so species of the bacteria

• Legionella Pneumophila part of serogroup 1

•

Legionella

� Where is it and what conditions does it like?� Can live in natural and manmade water systems� 25oC – 45oC (37oC optimum)� Stagnant slow moving water� PH 6.5 – 7.5PH 6.5 – 7.5� Uses sludge, scale, sediment, wood, rubber, rust are all

used as food sources� Raised CO2 and lowered O2, where growth is an issue

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� How does it affect us?� Legionella bacteria causes both bacterial infections

and allergic reactions� Legionnaires disease is the bacterial infection which

causes a type of pneumonia causes a type of pneumonia � Pontiac fever is the allergic reaction to the bacteria

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� Legionnaires Disease – the symptoms� Flu like with headaches� Followed by fever � Chills and a consolidating pneumonia� Chest and abdominal pains� Chest and abdominal pains� Vomiting and diarrhoea�Mental confusion

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� Legionnaires Disease – properties and prognosis� Does not respond to penicillin � Starts abruptly after a 2 – 10 day incubation period� Causes systemic damage to kidneys liver and CNS� Causes permanent damage to those who recover e.g. � Causes permanent damage to those who recover e.g.

scarring of the lung� Non-infectious (no person to person transfer)� Prognosis � Previously fit and well 12% fatality rate� Hospitalised patients 25% fatality rate� Aged / Immunosuppressed 45% + fatality rate

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200

250

0

50

100

150

0-9 10- 20- 30- 40- 50- 60- >70

Men

Women

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� Pontiac Fever – the symptoms and prognosis� Flu like symptoms� 24-48 hour incubation period� Spontaneous recovery within 48 hours� No recorded fatalities� No recorded fatalities� Can occur at the same time as legionnaires disease

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5%5%

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� How do we control it?

�Using Temperature - e.g. >60oC HWS and <25oC CWS

�Using Flushing – e.g. maximisation of water movement

�Using Chemicals – e.g. chlorine/chlorine dioxide etc.�Using Chemicals – e.g. chlorine/chlorine dioxide etc.

�Using Physical processes – e.g. ionisation/UV

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6060ooCC

At 70At 70 ooC C killed virtuallykilled virtually instantaneouslyinstantaneously

At 60At 60 ooC killed in 5 minutesC killed in 5 minutes

7070ooCC

� How does temperature affect legionella?

2020ooCC

3737ooCC

5050ooCC

6060ooCC

3737ooC Optimum growth rateC Optimum growth rateBelow 37Below 37 ooCC Multiplication decreasesMultiplication decreases

Above 46Above 46 ooC Growth ceases C Growth ceases At 50At 50 ooC can survive for a matter of hoursC can survive for a matter of hours

At 60At 60 ooC killed in 5 minutesC killed in 5 minutes

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� How can biocides affect legionella?

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� What does L8 ask of employers?� To identify and assess sources of Risk for all

water systems regardless of size or volume

� To prepare a Written Scheme (or course of action) for preventing or controlling the Risk.for preventing or controlling the Risk.

� To implement and manage the scheme -appointing persons to be managerially responsible - the “Responsible Persons”.

� To Keep records and check that what has been done is effective.

Legionella

� Case Studies� Golf Resort in Dundee (2008)� A party stayed in lodge with a hot tub� 2 of the party began to feel ill, running a temperature� A doctor prescribed antibiotics for both� A doctor prescribed antibiotics for both� One persons condition deteriorated over night� Blood test showed he had legionnaires disease� The other sufferer also had tests showing pontiac fever� Unfortunately the LD sufferer died as a result� Samples showed legionella bacteria in hot tub� No risk assessment in place� £120,000 fine, plus costs

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� Case Studies� Edinburgh 2012� 3 Fatalities from Legionnaires Disease� 101 confirmed or suspected cases� 2 companies served with improvement notices� 2 companies served with improvement notices� Notices for – failing to have a biocide treatment programme

or a failure to maintain it on cooling towers

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� HSE 5 year study results – July 2012� HSE produced a in-depth report on cases from last 5 years

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� It’s clear more can be done

� Many non-compliances out there

� Essential that risk assessments are completed and a written scheme is drawn up and maintained

� No excuses, controls are simple

� Thank you for your time

� Any questions