Following the outbreak of Pseudomonas that killed three babies in a neonatal maternity unit in Northern Ireland, industry experts have issued guidance to hospital trusts on how to reduce the risk of Pseudomonas bacteria in water supplies.
The Department of Health’s chief medical officer and scientific advisor, Professor Dame Sally Davies, has published updated advice to assist health providers in preventing and controlling the superbug in special care units.
She said: “It is important the NHS takes all the necessary precautions to minimise the risk of contamination with Pseudomonas. aeruginosa bacteria, which can cause significant infections in very sick patients.
“The guidance we are issuing today reminds healthcare providers of the importance of high standards of infection control. It also provides them with helpful advice on best practice to prevent Pseudomonas in specialist care units, and gives clear and concise information on how to manage the risks.”
The publication follows the deaths of three babies at the Royal Jubilee Maternity Hospital. They were all found to have contracted Pseudomonas , which was later traced to taps on the ward.
Last week, Northern Ireland Health Minister Edwin Poots announced a ‘full and rigorous’ investigation into the outbreak. The probe will be chaired by Professor Patricia Ann Troop, former chief executive of the Health Protection Agency (HPA), and will be facilitated by the Regulation and Quality Improvement Authority (RQIA). It will investigate the reasons for the outbreak, the actions taken, and any lessons that can be learned. These areas for improvement are expected to include the development of updated guidance on water treatment and monitoring practices in healthcare settings.
In England, the advice covers best practice for handwashing and risk assessment. For handwashing it states:
- Only use the hand wash stations for hand washing
- Do not dispose of body fluids at the hand wash station
- Do not wash any patient equipment in hand wash basins
- Do not use basins for storing used equipment awaiting decontamination
- Wash patients on augmented care units with water from outlets demonstrated to be safe through water sampling and risk assessment
- Use all hand wash stations regularly
- Flush taps regularly, either automatically or manually, and keep a record of when they were flushed
- Report any problems to the infection prevention and control team
- Do not locate alcohol gel dispensers at hand wash stations
- Use pre-filled single-use bottles for alcohol-based handrubs or cleaning solutions
- Ensure all staff are properly trained
Advice on risk assessment includes:
- Set up a water safety group to develop an action plan for each trust
- Develop separate risk assessments for Legionnaires and Pseudomonas
- Ensure correct clean and dirty separation is maintained
- Ensure taps and thermostatic mixing valves have been commissioned and routinely validated according to the manufacturer’s instructions
Pseudomonas is a genus of gamma proteobacteria, belonging to the larger family of Pseudomonads. It is widely found in soil and stagnant water and can infect humans and plants. The bugs do not usually cause illness in healthy people, but are ‘opportunistic’, and can pose a major threat to intensive care patients and those with compromised immunity, including babies in neonatal units, burns patients and those with cancer.
The Health Protection Agency says infection rates are pretty steady, with between 3,700 and 4,000 verified cases every year. Nine out of 10 of these are caused by the Pseudomonas aeruginosa strain, which was behind the recent outbreak in Northern Ireland.
The bugs do not usually cause illness in healthy people, but are ‘opportunistic’, and can pose a major threat to intensive care patients and those with compromised immunity
The most common route to patients is through medical equipment, particularly plastic or rubber catheters or feeding tubes, or contaminated hands. Good hand hygiene is therefore vital.
Pseudomonas bacteria also thrive in water systems, particularly large-scale ones such as those found in big industrial buildings, leisure centres and hospitals. Older buildings are particularly at risk as, when the water system is adapted for a change of use or to feed new buildings, deadlegs are created that provide a breeding ground for Pseudomonas bacteria.
Once in a water system, the bugs grow rapidly, creating a biofilm on pipework. This protects and harbours them and allows them to quickly multiply and take hold. Pseudomonas is known to flourish particularly well where it has access to a higher level of oxygen and the temperature is between 11˚C-44˚C, although some are able to multiply at just 4˚C.
Where the water supply itself is concerned, there should be a two-pronged approach; the first to prevent colonisation through regular maintenance and flushing of the system. This includes ensuring water is not allowed to stagnate and that cold water pipes and tanks, in particular, are regularly maintained, cleaned and disinfected.
Once detected, any outbreaks should be treated speedily using methods such as continuous dosing of systems with chlorine dioxide, the installation on silver-copper ionisation equipment, and the use of UV and ozone.
Expert comment
Hospital estates and facilities managers will now be facing increased pressure, both to test their own systems to ensure they are free from bugs, and to put in place robust treatment plans should they detect any bacteria.
“In many cases, the Pseudomonas growth is directly related to Legionella growth, and similar treatment regimens should be used for the control of both,” says Jill Cooper, group microbiologist at B&V Water Treatment.
Pseudomonas species are widely present in the environment and in many cases will be present in low numbers in the incoming mains supply to healthcare premises. They can cause problems within water systems as they produce biofilm on surfaces.
All healthcare premises should have a Legionella risk assessment and regular review every two years as part of their control programme, Cooper said. This should be carried out by a reputable water treatment company, which will have risk assessors with specific training and experience in conducting such investigations. The risk assessment will primarily look at the risk associated with the development of Legionella bacteria within the water system, but the remedial measures recommended will also pinpoint ways in which Pseudomonas growth within the system can be minimised.
The removal of unused pipework (deadlegs) and oversized water tanks are actions that can be taken to minimise the risk of Pseudomonas growth, she pointed out. A quality risk assessment will also recommend a flushing regimen that will prevent stagnation of the water within pipework and minimise the development of biofilm containing Pseudomonas species.
Older buildings are particularly at risk as, when the water system is adapted, deadlegs are created that provide a breeding ground for bacteria
Such a risk assessment will also generally recommend a microbiological sampling regimen, which may include sampling for Pseudomonas species. If a regimen is implemented, it is very important to sample the incoming mains so that any results obtained throughout the wider water system can be compared with incoming levels, Cooper stressed. If samples are found with much higher levels of Pseudomonas within the premises than those present in the incoming mains, it is clear that conditions within the system are such that growth of Pseudomonas species is supported. It is also likely that a biofilm is present.
“To minimise the risk of Pseudomonas it is critical to ensure there is no stagnation of the cold water system and that cold water tanks are maintained, cleaned and disinfected as necessary,” she stated.
“If all remedial actions have been completed and all on-going monitoring, such as flushing and temperature controls, are maintained and the problem persists it may be necessary to implement a chemical dosing regimen to the water system on site. Standard treatments include continuous dosing of the water system with chlorine dioxide, the installation of silver-copper ionisation equipment and, to a limited extent, the use of UV and ozone. Point-of-use filters can also be used to reduce risk, but do not address any underlying microbiological problems.”
Tom Pellereau is the brains behind Absulox, a new water treatment product from B&V Water
The NHS is currently in late-stage talks with B&V Water over the potential impact its new product, Absulox, could have in hospitals and healthcare buildings across the UK.
Designed specifically to kill water-borne microbes, including Pseudomonas and Legionella, the treatment and disinfectant product uses the active ingredient hypochlorous acid, which is found in the human body’s immune system and is used to fight infection. This means it is non-damaging to human tissue.
In trials, the substance has been found to eliminate pathogens within seconds. It can also help to maintain pipework, ensuring bugs do not return once eradicated.
B&V’s head of product development, Richard Sinden, said: “Absulox is going to have major ramifications as a new weapon in the fight against Pseudomonas and Legionella and is therefore potentially life-saving technology.”
Tom Pellereau, star of the TV show The Apprentice and the man behind the creation of the product, added: “This has the ability to kill bacteria fast, safely and when in situ. It provides a new weapon in the fight against deadly viruses.”
