The Legionella Control Association (LCA) looks at how Legionella can require different actions in healthcare settings.
Legionnaires’ disease is a potentially fatal illness that can affect anybody. As a healthcare-acquired infection, it has approximately three times the mortality rate compared to a community-acquired infection. In healthcare settings, there are usually enhanced control measures when compared to other buildings.
In this article we will explore some of these, but it is a specialist subject and those involved in legionella control in healthcare must be suitably experienced and competent.
Why healthcare?
People in a healthcare settings are generally more vulnerable to all types of infections. This may be because their illness makes them more susceptible, or their treatment may suppress their immune system.
In some cases, illness or treatment may make their immune system very weak and the patient particularly prone to infection.
These patients are typically treated in healthcare settings we call ‘augmented care’. Legionnaires’ disease in the general population mortality rate is 10-12 per cent. In healthcare settings the mortality rate can be >30 per cent, making Legionnaires’ disease a significant healthcare acquired infection.
Putting this in overall context, there are many more deaths from other infections in hospitals than there are from Legionella, but Legionella remains an important waterborne pathogen that must be managed
Overview
Legionnaires’ disease is a potentially fatal type of pneumonia, a bacterial lung infection. The disease is contracted from bacteria of the genus Legionella, within a water-based aerosol, entering the lungs. Exposure is generally preventable if water systems are properly maintained.
There are legal implications where there are failures to control this risk.
Legionella growth is considered a risk regardless of the strain or species of Legionella. Those responsible for healthcare buildings have a legal duty to control the risk.
The most recent data from PHE records 503 clinically diagnosed cases of Legionnaires’ Disease in England in 2019. It is estimated that there are around 6,000-9,000 undiagnosed cases each year in the UK.
Legionella proliferation
There are fundamental principles that reduce the risk of Legionella growth in water: avoid Legionella growth temperatures (20-45C); avoid stagnation so Legionella doesn’t have time to grow; avoid materials of construction that will support growth; control the release of water spray to minimise transmission risk; keep the system and the water in it clean so nutrients for Legionella are minimised; use water treatment techniques, particularly where any of the above cannot be controlled; and maintain the system properly.
These principles form the basis of the requirements of HSE’s Approved Code of Practice for the control of Legionella in water systems and HTM0401 – the health technical memoranda for Legionella control.
Legionella and the law
The Law applicable to Legionella control in most settings is the Health and Safety at Work Act (HASWA), but in healthcare the Health and Social Care Act (HSCA) takes precedence for patient aspects.
All regulated healthcare activity must be registered with the Care Quality Commission under HSCA.
HASWA describes the responsibility of an employer to protect their employees and any other stakeholders from risks that may arise from their undertaking.
HSCA regulation 12(2)(h) and regulation 15 contain the principles for legionella control: 12(2)(h) - risks of infection must be assessed, prevented, detected and controlled, including those that are health care associated; and 15 - facilities must be clean, secure, suitable, properly used, properly maintained and appropriately located.
Enforcement in healthcare premises where the patient is involved is the responsibility of the CQC under a memorandum of understanding between HSE and CQC. Where staff or other third parties are involved, the HSE lead enforcement action.
Different types of healthcare buildings Healthcare buildings are defined in HTM0401 as anywhere where healthcare is delivered.
This is a very loose definition and covers a wide range of risk levels. Healthcare settings in general tend to be higher risk environments for waterborne pathogens such as Legionella for two reasons: they tend to have complex and extensive water systems and patients are more susceptible.
These two factors are not fixed and will vary from building to building. e.g. a doctor’s surgery may have small and relatively simple water systems, but large hospital will often be very complex and involve systems that require careful monitoring, such as recirculating hot water. Oncology patients will generally have greater susceptibility compared to musculoskeletal patients.
Risk assessment
Healthcare premises must have a Legionella risk assessment.
This identifies risks associated with water systems and includes recommendations for elimination or substitution of the risk and for control scheme or water safety plan tasks to mitigate residual risk.
Risk assessment must be specific to water systems; with consideration given to the susceptibility of individuals who may be exposed. In healthcare settings, Legionella risk assessment is likely to be only part of a wider suite of risk assessments for all water based hazards.
Water safety groups, water safety plans and control measures
Any risk that is present needs to be controlled to an acceptable level.
The HSE uses the term as low as reasonably practicable (ALARP), and this is the target level of risk. Legionella control measures usually include maintaining temperature, use of water treatment, flushing and physical control.
In healthcare settings it is usual to have a water safety group (WSG). The WSG is a multidisciplinary group formed to oversee the commissioning, development, implementation and review of a water safety plan (WSP).
The aim of the WSG is to ensure the safety of all water used by patients/ residents, staff and visitors, to minimise the risk of infection associated with waterborne pathogens.
WSGs include stakeholders from estates, infection control, medical microbiology, nursing, augmented care, housekeeping/support services, specialist users of water (such as renal units), etc. There may also be an Authorising Engineer/independent adviser to provide external competent technical advice.
Healthcare organisations should have a WSP, which is a holistic safety plan for all water hazards.
This will usually incorporate all the various water based risk assessments (including Legionella) and their control measures. Where risk mitigation measures have conflicting outputs, they should be resolved as part of the holistic plan. e.g. measures to mitigate scalding risk can compromise measures to mitigate microbiological risk.
Positive Legionella results
In many healthcare settings, routine Legionella samples are included in the WSP. This is because the occupants have been identified in the risk assessment as a population more susceptible to legionnaires’ disease.
There is detailed specific advice within HTM0401 part B on response to positive legionella samples. Legionella Control Association (LCA) The LCA Code of Conduct is highlighted in ACoP L8 (Paragraph 83) as guidance to what standards service users should expect.
A voluntary membership with around 400 Members, LCA registered companies are specialists in Legionella Control.
The LCA audit members’ work to the LCA service delivery standards. Legionella risk assessment in healthcare settings is a specific subcategory for this auditing. Training and competence of those involved in service delivery is scrutinised and deficiencies must be addressed.
Summary
Legionnaires’ disease is potentially fatal but preventable.
Dutyholders in healthcare premises have a legal duty to ensure risks are identified and controlled. Legionella prosecutions can result in large fines and custodial sentences, and it is not necessary for there to be a death or case of disease for a successful prosecution.
