Legionella control in health and aged care facilities

When exposed to Legionella, most healthy individuals will not develop an illness, or will develop Pontiac fever rather than Legionnaires’ disease, but newborn babies, the very old and people with compromised immune systems are at increased risk of Legionella infection. Legionella is therefore of significant concern in health and aged care facilities because of the presence of people with clinical risk factors that increase both the likelihood and the potential severity of Legionella infection.

People at highest risk of acquiring legionellosis in healthcare facilities are:

• newborn babies (water birthing is a particular risk)
• older people (the disease is rare in children and most cases occur in people over the age of 50)
• males
• smokers
• people with
• chronic obstructive pulmonary disease
• diabetes
• therapeutic immunosuppression
• transplant immunosuppression
• diseases that result in immunodeficiency (eg HIV/AIDS)
• people undergoing chemotherapy.

Additional risk factors for healthcare associated infections include recent surgery, intubation and mechanical ventilation, aspiration of water contaminated with Legionella including nasogastric feeds and the use of respiratory therapy equipment contaminated with Legionella. Risks are further elevated if there has been recent plumbing work which has caused disturbance of biofilm or a prior history of nosocomial cases in the healthcare facility, given the difficulties of eradicating Legionella.

Potential sources of Legionella in a hospital setting include:

• Water distribution systems;
• Cooling water systems;
• Showers
• birthing pools and hydrotherapy pools;
• Respiratory therapy equipment
• Humidifiers;
• Decorative fountains;
• Ice machines

The management of Legionella risk in healthcare facilities is an ongoing process that involves the establishment, implementation and maintenance of control measures. The control measures and their maintenance should be documented in the risk management plan, and should be regularly monitored and reviewed for their effectiveness in reducing the overall risk.

The potential health risk posed by Legionella spp. within a healthcare facility can be mitigated by the application of appropriate air handling and water distribution system design, operation, maintenance, and management.

All healthcare facilities in WA require to have a water management plan to reduce the risk for Legionnaires’ disease associated with a building water system and devices. This water management plan should identify areas or devices in the building where Legionella might grow or spread to people so that the risk can be reduced.

The following Guidelines and Standards are available to assist in risk mitigation and ensure that the water management plan is comprehensive, effective, and in line with the relevant Guidelines and Standards:

• Australian Standard 3666 Part 1 to 4 Air-handling and water systems of buildings—Microbial control.
• The national standard for design, installation, commissioning, cleaning, operation and maintenance of air handling and water distribution systems. (This standard is adopted by the WA Health (Air-handling and Water Systems) Regulations 1994).
• enHealth Guidelines for Legionella Control in the operation and maintenance in water distribution systems in health and aged care facilities (enHealth Guidelines) published by enHealth in 2016 and endorsed by the Department of Health WA.
• The enHealth Guidelines provide a risk-based framework for controlling Legionella in health care settings, including routine water quality testing to verify that implemented measures (which can include engineering, maintenance and operational control) are having effect.
• Western Australia Health Facility Guidelines for Engineering Services
• Provide engineering design and operation guidelines for health facilities in WA. These guidelines apply to facilities built by the sector, hospitals and day procedure facilities. Compliance with the guidelines is mandatory when designing and operating public and private health facilities in WA.
• Australian Drinking Water Guidelines
• The national framework for safely managing drinking water as supplied to health facilities.

The enHealth Guidelines is supported by the National risk management plan template for legionella control in the operation of water systems (Word 500KB).

A risk management plan (RMP) is a document used to effectively manage water safety in the water distribution system within a facility. Steps in a risk management plan help to:

• describe a facility’s water distribution system
• identify the hazards, hazard sources and hazardous events relevant to the water in a facility’s water distribution system
• assess the risks associated with the identified hazards, hazard sources and hazardous events
• state the control measures to be implemented for the identified risks
• state how the control measures and effectiveness of the risk management plan will be monitored (operational monitoring and verification monitoring), including the corrective actions to be undertaken in response to obtaining a monitoring result outside a critical limit
• state the record keeping methods to be implemented for the risk management plan and
• state the frequency at which reviews of the risk management will occur.

The Environmental Health Directorate held a full-day Legionella Control in Healthcare Facilities Workshop on 28 October 2024. The workshop was targeted to the Health Service Provider’s and WA Health hospital facility managers and engineers who manage water-based air handling and water distribution systems in healthcare facilities. The aim of the workshop was to improve knowledge and skills regarding legionella risks and controls in healthcare facilities water distribution systems.

  The workshop videos can be accessed via the links below:

• Legionella and Healthcare Facilities – David Speers, PathWest (external site)
• Legionnaires disease investigations -Jaala Downes, Department of Health (external site)
• DOH Audit of Hospitals & Auditor General Report – Brian Labza, Department of Health (external site)
• Legionella Worksafe’s Role - Mark LEWIS, WorkSafe Division (external site)
• Health Air Handling and Water Systems Regulations – Richard Theobald, Department of Health (external site)
• Risk Management Framework and Audit Tool – Natalia Ramswell, Department of Health (external site)
• Royal Perth Hospital Legionella management – Ron Javat, Royal Perth Hospital (external site)
• Legionella control at Fiona Stanley Hospital – Rima Tamang and John McDonald, Fional Stanley Hospital (external site)