Andrew Vickers and
Andrew Brown–
Health Protection Programs
Public Health Services

> High risk facilities vs high risk systems
> Legionella risk
> Case investigations in high risk facilities
> Responding to identified risks
> Case studies

> The Legionella Regulations focus on high risk manufactured water systems (warm water systems)
> All types of potable water system (residential and commercial) can (and do) become colonised with
Legionella bacteria
> Healthcare and residential aged care facilities are high risk regardless of the types of systems
> Managing the risk requires a deliberate and coordinated effort

> Water safety guidance – designing and implementing water safety risk management plans

> Risk = Exposure ( to hazard ) x Probability x Severity
> Hazard: Legionella bacteria
> Legionnaires' disease is a serious and sometimes fatal form of pneumonia
> In addition to L. pneumophila , 20 Legionella species have been documented as human pathogens on the basis of their isolation from clinical material
(Diederen 2008)
.

> Risk = Exposure (to hazard) x Probability x Severity
> Exposure (aerosol):
> Showering
> 3500 – 35000 - 350000 CFU/mL
Source: An in-premise model for Legionella exposure during showering events.
by Schoen, Mary E and Ashbolt, Nicholas J, 2011

> Dental handpieces
> Nebulisers
> Humidifiers
> Water misters
> Spas
> Decorative fountains
> Taps
> Toilets
> Microaspiration of contaminated water into the lungs could be the mode of transmission in some cases
(Diederen 2008)
.
• Drinking water and ice machines

Risk factors for pulmonary microaspiration are:
> Being less alert due to medicines, illness, or other reasons
> Drinking large amounts of alcohol
> Dental problems
> Medicine to put you into a deep sleep for surgery
(general anaesthesia)
> Old age
> Poor gag reflex in people who are not alert (unconscious or semi-conscious) after a stroke or brain injury
> Problems with swallowing

> The highest risk of pneumonia linked to pulmonary microaspiration is seen in elderly individuals with a history of:
> •lung disease
> •seizures
> •stroke
> •dental problems
> •needing help eating

> Risk = Exposure (to hazard) x Probability x Severity
> Susceptible people (likelihood and severity/mortality increase with susceptibility):
• decreased immunity
• chronic diseases of the respiratory system
• renal deficiency
• diabetes
• old age
• people treated with corticosteroids
• tobacco smokers
• alcohol abusers
Source: Assessing Risk of Legionella by Andrew J Cooper; Howard R Barnes;
Eric R Myers 2004
• highest risk = use of immunosuppressive or immunodeficiency
> Hospitals and aged care facilities are high risk due to the susceptibility of patients/residents

> Regulated systems should not be the focus; compliance with regulations does not prevent colonisation
> Consider hot, cold and warm water
> Consider other exposure sources (dental chairs, humidifiers, misters, fountains, irrigation etc.)
> Consider microaspiration of drinking water (including chilled water) as a possible source.
> Collect samples to be representative of the systems and potential exposures. Rapid PCR method?
> Check storage and return temperatures on hot water loops
> Investigate solar preheat systems
> Review sampling and risk management plans
> Precautionary decontamination?

> Regulated notifications and disease investigations
> Any Legionella in a high risk facility water system is an unacceptable risk
> Ongoing notification (every annual inspection) = ongoing risk
> Prescribed chlorine decontamination is inadequate to resolve long term colonisation
> Removing dead legs and tap aerators, servicing TMVs, self draining shower hoses, tap flushing etc. will not resolve long term colonisation
> In many instances, ongoing/long term residual disinfection (chlorination) of cold incoming mains water is necessary – complex and difficult
> Precautionary decontaminations may be required in some case investigations

> LP2 case – onset late 2011
> Elderly female resident of suburban residential aged care facility
> Did not leave the facility during the incubation period
> No cooling towers nearby
> Regulated warm water system
> Case’s shower - 20 cfu/ml LP2-14 ; 240 cfu/ml LESP
> Case’s hand basin - 1700 cfu/ml LESP
> Previous notifications:
Sample   date
March   2011
May   2011
Source
2   x   Handbasins
Shower
Sample   type Result
Post
Decontamination
20   &   100   LP2
Annual   inspection 110   LP2 ‐ 14
‐ 14

> LP1 case – onset mid 2012 - fatality
> 70yo female terminally ill palliative care patient
> Had not left room (bedridden and sponge bathed)
> New facility (Dec 2011) with new plumbing and new meter
> No pre-commissioning chlorination conducted in accordance with appendix 1 of AS/NZS 3500.1:2003
> Investigation focussed on micro aspiration
> 100/mL LP1 found in sample from chilled drinking water dispenser serving ward
> Samples from four other chilled water dispensers at the facility contained LP1 (range 100-5300 cfu/mL)
> Also found issues with faulty boiler on HWS

> LP1 case – onset late 2013 - fatality
> Retirement village (SRF)
> Hot water system with TMVs
> Visual check of boiler temperature gauge indicated >60C
> Thermometer check of hot water indicated water was being stored at approx. 45C
> Hot and cold water pipes bundled together
> LP1 found in water samples from the shower and hand basin in case’s room (100 cfu/mL)
> SBT indicated match with clinical isolate
> LP2-14 & LESP found in warm and cold water throughout the facility (range 10-500 cfu/mL)
> No water management plan – no Legionella monitoring

> LP1 case – onset early 2014 - fatality
> 89 yo male resident of suburban residential aged care facility
> Did not leave the facility during the incubation period
> Registered warm water system
> LP1 found in hot and cold water samples from case’s room (range 40-750 cfu/mL)
> SBT indicated match with clinical isolate
> LP1 found in water samples from numerous other rooms throughout the facility (range 10-700 cfu/mL)
> Ongoing and regular history of Legionella detection (13 notifications total) 2009, 2010, 2011, 2012, 2013 prior to case notification