OverviewWhat is legionella bacteria?How does it affect us?How do we control it?Case StudiesHSE 5 year study results
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 •
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
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
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
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
Legionella 250 200 150 Men 100 Women 50 0 0-9 10- 20- 30- 40- 50- 60- >70
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
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
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
Legionella How can biocides affect legionella?
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.
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
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
Legionella HSE 5 year study results – July 2012 HSE produced a in-depth report on cases from last 5 years
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