Presentation from NESHEP\'s October 2012 meeting - covering Legionella by Steve Taylor (OEL-APIX)

1. Legionella
Recap and Update

2. Overview
What is legionella bacteria?
How does it affect us?
How do we control it?
Case Studies
HSE 5 year study results

3. Legionella
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
•

4. 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 – 7.5
Uses sludge, scale, sediment, wood, rubber, rust are all
used as food sources
Raised CO2 and lowered O2, where growth is an issue

5. Legionella

6. Legionella
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
Pontiac fever is the allergic reaction to the bacteria

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

8. Legionella
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.
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

9. Legionella
250
200
150
Men
100 Women
50
0
0-9 10- 20- 30- 40- 50- 60- >70

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

11. Legionella
5%

12. Legionella
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 Physical processes – e.g. ionisation/UV

13. Legionella
How does temperature affect legionella?
70oC At 70oC killed virtually instantaneously
60oC At 60oC killed in 5 minutes
50oC At 50oC can survive for a matter of hours
Above 46oC Growth ceases
37oC 37oC Optimum growth rate
Below 37oC Multiplication decreases
20oC

14. Legionella
How can biocides affect legionella?

15. Legionella

16. Legionella
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.
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.

17. 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
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

18. Legionella
Case Studies
Edinburgh 2012
3 Fatalities from Legionnaires Disease
101 confirmed or suspected cases
2 companies served with improvement notices
Notices for – failing to have a biocide treatment programme
or a failure to maintain it on cooling towers

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

20. Legionella

21. Legionella

22. Legionella

23. Legionella
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