4.1 Water

Vulnerable (high-risk) patients may be at a greater risk of infection from water system-associated organisms following exposure to water within healthcare settings during the delivery of healthcare.

It is important that the potential infection risks from water systems are understood by those delivering care. This chapter sets out guidance to help reduce this risk.

 

4.1.1 High-risk patients

High-risk patients

High-risk patients are those who are vulnerable to infection as a result of a compromised immune system, underlying health conditions and associated medical treatments. 

High-risk patient groups should include as a minimum:  

• haematology
• oncology
• cardiac surgery
• bone marrow and stem cell transplant patients
• neonatal, paediatric and adult intensive care unit (ICU) patients
• transplant
• burns
• any other patients that are severely immunocompromised through disease or treatment

The types of infection that water system-associated organisms may cause include:

• bloodstream (including CVC-associated bloodstream infection)
• respiratory (pneumonia)
• skin and soft tissue (including insertion site infections around any invasive device)
• surgical site infection (for example endocarditis after cardiac surgery, wound infections)
• urinary tract infection (UTI)
• disseminated disease

Patients may become infected, colonised before they become infected or may be colonised with no active infection. 

4.1.2 Responsibilities

Water Safety Group (WSG)

Each NHS board should have a multidisciplinary water safety group. SHTM 04-01 part B describes in detail the role, responsibilities and membership of the WSG.

As a minimum this WSG should:

• have in place board water safety plans (WSP)
• identify high-risk patient groups and areas across all healthcare settings and include these in the WSP
  • high-risk patients can receive care or treatment out with high-risk settings (for example theatres or radiology) and this should also be considered within the WSP
• review all uses of water within healthcare settings and include these in water safety plans
• review risk assessments and water safety plans on a pre-agreed frequency (minimum annually) and when there are alterations, repairs, changes of use, building works, and incidents.
• have ongoing input throughout any new build or refurbishment project process including commissioning, handover and any associated HAI-SCRIBE
• have general oversight of water quality across the NHS board area
• confirm that water is of potable quality and that any other minimum testing requirements are being met
• ensure routine water testing is being undertaken where required
• review results, provide assurance and/or act upon out of specification water testing results
• ensure that clear responsibilities are defined for the interpretation, dissemination and actions of water results
• be assured that flushing requirements across the NHS board are being met including those areas which have low or altered occupancy and any which are unoccupied
• have an agreed plan regarding point of use (POU) filters which includes their requirement, selection, fitting, ongoing maintenance and their review
• ensure that HCWs, patients and care givers are supported to comply with and understand the importance of safe use of water practices
• comply with the roles and responsibilities as described in SHTM 04-01 Part B

4.1.3 Safe clinical care

• Safe use of water
• Minimise patient contact with tap water
• Use of sterile water
• Milk
• Use of ice

Safe use of water

It is important that the potential HAI risks from water systems are understood by those delivering care, specifically the potential transmission routes for water system-associated organisms, which can include:

• direct contact with water, for example oral care, washing and bathing, hydrotherapy
• indirect contact with contaminated equipment, medical products, staff and other patients
• aerosolisation from aerosols generated from the process of water splashing and spraying, and aerosols released from contaminated water-based equipment for example cardiopulmonary bypass machines and heater-cooler units used during cardiac surgery
• aspiration from inhalation of contaminated water into the airways, usually by patients that are intubated, via nasogastric tubes (where the contaminated water has been used to prepare the food), those requiring oral fluid replacement and those requiring orally administered medications

Minimise patient contact with tap water

Staff should consider the location and proximity of high-risk patients to tap water, drains and any associated splashing or spraying.

Alternatives to tap water, such as cleansing wipes, hand rub and water free shampoos should be considered while taking into account patient needs, patient choice and infection risk.

Use of sterile water 

• For severely immunocompromised patients, for example allogeneic stem cell transplant patients, sterile water should be considered for drinking, oral care and washing.
• Sterile water should be considered to replace tap water for washing babies within neonatal settings specifically for babies that:
  • are under 28 weeks gestation
  • have non-intact skin
  • have invasive devices 
  • are in humidified incubators

Milk

Powdered infant formulas should be prepared using freshly boiled water according to manufacturer’s instructions.

Frozen breast milk should be defrosted in one of the following ways:

• using a water-free warming device
• in a designated fridge
• at room temperature 

Any water free warming devices should be single patient use, and stored in an appropriate, clean and patient identifiable container, with a fitted lid.

Once defrosted, any unused milk should be discarded in accordance with local waste policy and never disposed of via a clinical wash hand basin (CWHB).

Use of ice

Installation of ice machines should be by approval of the Water Safety Group (WSG) and in accordance with manufacturer instructions and SHTM 04-01 Part A . A WSG approved cleaning, maintenance and audit schedule should also be in place.

Ice for consumption

• Ice for consumption by high-risk patients should not be made using ice-making machines.
• Where ice is required for consumption in these patient groups, it should be made by putting drinking water into single-use ice-making bags and frozen in a conventional freezer.
• Alternatively, iced water may be provided by freezing single bottles of commercially available spring water and allowing patients to drink that ice water as it melts.

Ice for treatment

• Where ice is required for treatment purposes by high-risk patients, it should not be made using an ice machine. It should be made using water obtained through a microbiological point of use (POU) filter, sterile water, or cooled boiled water in single-use ice-making bags and frozen in a conventional freezer. 
• Conventional freezers used in healthcare should be maintained and cleaned in line with manufacturer’s instructions with an agreed cleaning, maintenance and audit schedule in place.

4.1.4 Management of water outlets including taps and showers

• Clinical sinks including wash hand basins - safe practice points
• Showers 
• Surface contamination from spraying or splashing during water outlet use
• Flushing

 

Water outlets that are used infrequently or not at all may present a transmission risk from stagnant water and have the ability to contaminate the wider water system. Consideration should be given to removal of the outlet where there is no longer a clinical need for it. See SHTM 04-01 Parts A & B for further information.

Clinical sinks including wash hand basins – safe practice points

Below is an educational animation which focuses on clinical wash hand basins (CWHBs), their intended purpose, water associated infection risks, and what we all can do together to reduce this risk. The animation is supported by a poster for use beside CWHBs to locally promote good practice for health and care staff as well as the general public who may visit those settings. 

Animation: Good practice for clinical wash hand basins 

Poster: Good practice for clinical wash hand basins 

• All clinical sinks and CWHBs should conform to SHTM 64.
• There should be enough space in the sink to allow the required activity to be performed without touching the basin sides, fixtures, or fittings (for example, taps), including whilst point of use (POU) filters are installed.
• When filling equipment such as patient wash bowls these items should not touch the taps, POU filter, basin sides or drain outlet.
• Water flowing from the tap should not be able to flow directly into the drain as this can cause splashing.
• Hand hygiene product dispensers should be placed so that the contents cannot leak or spill into/onto water outlets.
• Clinical wash hand basins should only be used for the purpose of performing hand hygiene.
• Clinical wash hand basins should not be used for disposal of any foodstuffs, drinks, bodily fluids, clinical or medicinal waste.
• Do not wash or place medical or patient care equipment in clinical wash hand basins, patient sinks, showers or baths.
• Equipment should not be stored on or near to the sink.
• Personal items (for example toothpaste, cosmetics) should not be stored on the sink.

Showers

• Shower heads and hoses should be allowed to drain after use so that water is not retained in a loop in the hose
• The shower hose should not be long enough to allow the shower head to touch the shower drain or floor.
• Showers should be included in the flushing programme.

Staff should report any problems or concerns regarding the safety, maintenance, usage, and cleanliness of water outlets to the appropriate service for example estates and facilities department/ancillary staff.

Surface contamination from spraying or splashing during water outlet use

Water flowing from taps during use should not create any splashing onto surrounding surfaces or equipment.

• Drug preparation, aseptic or other clinical procedures should not be carried out in close proximity to sinks, water outlets or within surrounding areas where splashing may occur.
  • Splash zones may occur up to 2 metres from the water outlet, however risks should still be considered in areas where splash or spray exceeds this distance to manage these risks locally.
  • Other factors to consider include the environmental layout, location of equipment (fixed and moveable), placement of patients, whether patients are high risk, and the activities to be undertaken.
• If there is splashing of surrounding areas and relocation or reconfiguration of the water outlet is not possible, physical barriers such as impermeable, wipeable screens capable of withstanding cleaning agents can be considered.

Flushing

Flushing of taps should be undertaken at all outlets (See SHTM 04-01 Part B)  including little used outlets and outlets within low occupancy areas.

All departments should identify a responsible person to ensure that flushing of all outlets are being performed in their areas as specified, in practice this may be the Senior Charge Nurse, Clinical Lead or domestic manager.

• In high-risk settings, all outlets should be flushed at least daily for one minute.
• In all other settings, all outlets should be flushed twice weekly as a minimum for at least three minutes in occupied buildings and should be based on local risk assessment, taking into account the local water pressure, temperature and flow rate.
• For any outlet currently fitted with a POU filter, the filter should not be removed in order undertake flushing. 
• Outlet flushing should not cause splashing/spraying beyond the outlet. If flushing creates splashing or spraying onto adjacent surfaces, the area should be cleaned/disinfected (as per NIPCM Chapter 1) to reduce the risk of contamination and slippages and falls.
• Records should be maintained to demonstrate that flushing has been undertaken and for the appropriate duration.
• Using a pre-existing daily schedule to incorporate flushing, for example the local domestic cleaning schedule, can increase compliance.
• All staff involved with flushing responsibilities should be appropriately trained.

4.1.5 Water dependent equipment

• Neonatal incubators
• Cardiac cooler units
• Refillable bottles

 

Water dependent equipment includes any items of equipment that comes into direct or indirect contact with a patient or their environment and also uses or requires to process or hold water to function.

Water dependent equipment, is a potential infection source and should be considered as potential sources for infection as part of outbreak or incident investigations.

Neonatal incubators

• Sterile water (not tap water) should be used within humidifiers for neonatal incubators in accordance with manufacturers instructions.
• Neonatal incubators (including mattresses) should be completely dismantled, cleaned, decontaminated and thoroughly dried between patients (or every 7 days when used continuously by the same patient), using cleaning products that are compatible with the equipment and in accordance with manufacturer’s instructions. Any moisture left within or on the incubator can encourage microbial growth.
• The re-usable reservoirs of humidified incubators should be cleaned and sterilised between uses in a central decontamination unit, if manufacturer guidance allows.

Cardiac heater cooler units

• Health and care settings should refer to NHSScotland Guidance for Decontamination and testing of Cardiac Heater Cooler Units (HCUs).

Refillable bottles

• Refillable bottles should not be used in high-risk settings where patients receive care.
• Where appropriate for use, refillable bottles should be washed and thoroughly dried and protected from environmental contamination. Any moisture may promote the growth of microorganisms. 
• Products used in refillable bottles should be freshly made (never topped up) and discarded after 24 hours (or sooner as dependent on the solution). Manufacturer’s instructions should also be followed.

4.1.6 Point of Use (POU) filters

A POU filter is an external filter that is fitted to a water outlet (taps and showers) to filter out microorganisms and debris.

A POU filter does not remove or kill the microorganism, but traps micro-organisms allowing for the safe use of the water.

The water safety plan (WSP) approved by the WSG should state the types of POU filter which can be used. The WSG should agree local processes and responsibilities for the requirement, installation, maintenance, management and removal of POU filters.

• Installation of POU filters may be considered by the WSG or an IMT where a potential or actual clinical risk has been identified as being associated with the water.
• Ensure when a POU filter is fitted there is no additional splashing or spraying of water and that water does not flow directly into the drain.
• POU filters should be replaced as per manufacturer instructions or if visibly contaminated, damaged, or leaking.
• POU filters may be removed when the Water Safety Group and/or IMT determines that water quality can be maintained without the use of the filter.
  • Once the POU filter is removed the outlet and its associated pipework should be immediately cleaned and flushed to remove any accumulated debris.

 

4.1.7 Water testing

• Water testing at commissioning 
• Routine water testing
• Frequency of testing 
• Microbiological limits
• Selection of outlets for sampling
• Interpretation of routine water testing results

 

It is important that responsibilities for routine and ad hoc water testing are well defined by the Water Safety Group.

Each NHS board should have processes in place for the receipt, reporting and distribution of results which should include as a minimum:

• escalation of out of specification results. Exceptions should be recorded and rapidly disseminated to all WSG members and local IPC team (a record should be kept of distribution lists for reporting)
• clear responsibilities should be defined for interpretation and action of results

Water testing at commissioning

• In order to ensure IPC input and oversight of risk, IPC teams should be involved in the design and planning process and engaged through to commissioning and handover. This includes agreeing acceptable water sampling parameters and remedial actions to be taken if results are unacceptable.
• A full set of the analysed water sample results should be approved by the WSG before handover and before the system is brought into clinical use
• The WSG should confirm water is of potable quality and meets other minimal water testing requirements with clinical and microbiological oversight from the ICD/microbiologist on behalf of the WSG.
• After water system replacement/remedial activities, water sample analysis results should be approved by the IMT/ WSG or agreed local process.

What to test

A sampling plan with appropriate microbiological parameters and should be agreed by WSG prior to tender. As a minimum it should include testing in all settings for:

• Total Viable Counts (TVCs)
• coliform bacteria (including E.coli)
• Legionella spp.

Testing for P. aeruginosa should be carried out in high-risk settings.

Local risk assessment should determine if there are additional testing requirements.

When to test

Samples should be taken no sooner than five days and no later than seven days after a full disinfection process has been completed and a further set of samples should be taken immediately prior to handover.

• Analysis should be carried out by an independent accredited laboratory (United Kingdom Accreditation Service (UKAS) or ISO 9002). See SHTM 04-01 Part C.

Actions following commissioning results

As part of their commissioning water safety plan, the NHS board should have pre-agreed processes in place should the results of commissioning tests be unsatisfactory. For more details on commissioning, see SHTM 04-01 Part A and BS 8680.

Routine water testing

Results from routine water testing over time (trend analysis) provides evidence of effective control measures and also supports early detection of HAI risks.

What to test

The WSG should agree the routine water testing required and this should form part of the water safety plan. As a minimum:

• routine water testing should be undertaken for Pseudomonas aeruginosa and Legionella species in high-risk settings and areas where high-risk patients are treated
• a local risk assessment according to BS 8580-1 and BS 8580-2 should be undertaken to assess the need for routine water testing in other care areas and for organisms other than Legionella and Pseudomonas aeruginosa
• consider trend analysis for Total Viable Counts (TVCs) to monitor water quality as this may indicate when results are deviating from what is considered normal for that particular water system
• equipment and/or medical procedures that use water which is separate from the main hot and cold water distribution system should be routinely tested in line with relevant guidance/manufacturer’s instructions which includes:
  • water for heater cooler units (NHSScotland Guidance for Decontamination and testing of Cardiac Heater Cooler Units (HCUs)
  • water used for renal dialysis 
• Where no UKAS accreditation exists for routine testing of specific healthcare water system-associated microorganisms, boards should still consider testing. The UKAS Technical Bulletin highlights the following important points.
  • There will always be new and emerging organisms causing outbreaks, for which there will not yet be established or accredited methods but where microbiology testing laboratories play a vital role in determining the source of infection.
  • There is significant risk to patients if sources during outbreaks are not detected and mitigated against. The lack of UKAS accreditation for a specific test does not preclude laboratories from processing these samples. Such specimens can be processed provided the laboratory states on the report that the test is not UKAS accredited.

Frequency of testing 

As a minimum, testing for P. aeruginosa and Legionella spp. in high-risk settings should occur every 6 months.

The frequency of routine microbiological water testing in other areas and for other microorganisms should be based on a comprehensive risk assessment undertaken by the WSG.

Increases to the frequency of water testing should occur:

• during a suspected or confirmed outbreak where a link to the water system is being explored or considered
• if surveillance identifies an increased incidence of infection known or suspected to be associated with the water system
• after implementing any changes to the water system for example after biocide dosing, remedial works or a refurbishment project
• when thermal or chemical controls have failed or are failing (for example when levels of biocide are lower than the agreed limit)

Consideration should be given to increasing the frequency of routine water testing when pre-flush trend analysis demonstrates increasing colony forming units (cfu)/100 ml for P. aeruginosa.

Microbiological limits

Healthcare water systems

Recommended microbiological limits for water samples are detailed in the table below.

Note: Incubate drinking water system samples at 22˚C and 37˚C for 24 hours in accordance with BS EN ISO 6222.

Microbiological limits for healthcare water systems

Pathogen	Colony Forming Units (CFU)
Coliform bacteria (including Escherichia coli)	0 cfu/100ml
Enterococci	0 cfu/100ml
P. aeruginosa	0 cfu/100ml
Legionella spp.	Undetectable in high-risk units. <100 cfu/litre in non-high-risk units
Legionella pneumophila serogroup 1 (Lp1)	Undetectable
For all other gram-negative healthcare water system-associated organisms	0 cfu/ml

 

Additional microbiological limits 

The table below details recommended additional microbiological limits for water samples obtained from water dependent equipment.

Recommended additional microbiological limits for healthcare procedures that present an increased risk

Procedure	Colony Forming Units (CFU)	Total Viable Count  (TVC)	Endotoxin
Heater cooler unit water	0 cfu/100ml for Mycobacterium spp.	TVC cut-off levels of <100 cfu/ml	None
Hydrotherapy water	<20 cfu/litre for Legionella spp. 0 cfu/100ml for Staphylococcus aureus as part of wider investigations only (local decision)	TVC cut-off levels of <10 cfu/ml	None
Endoscopy final rinse water	0 cfu/100ml for Mycobacterium spp.	TVC cut-off levels of <10 cfu/100 ml	Endotoxin limit of <0.25 EU/ml
Final rinse water in surgical instrument washer disinfectors	TVC cut-off levels of <1 cfu/100 ml	None	Endotoxin limit of <0.25 EU/ml
Renal dialysis fluid and water	TVC cut-off levels of <50 cfu/ml	None	Endotoxin limit of <0.125 EU/ml

 

 

Selection of outlets for sampling 

For routine testing, samples collected should be pre-flush only unless otherwise directed by the WSG/IPCT or Microbiology.

• Pre-flush sampling in a busy ward may have to occur early in the morning or at another time when water outlet usage is lower.
• Pre-flush samples should be taken by collecting water straight from the outlet as it is first turned on.
• Pre-flush samples may help to identify colonisation in a particular outlet.

If post-flush samples are to be taken, the sample should be collected after first running the outlet to flush through the pipes. Post-flush samples may support differentiation between local and systemic colonisation following a positive pre-flush result (see BS 7592 for more information).

A planned targeted sampling plan should be developed by the WSG to include:

• up-to-date schematic of the systems, including identified sampling points
• risk assessment and identification of water sampling requirements which ensure areas identified as high-risk in terms of patient susceptibility are included
  • high-risk also includes areas supporting microorganism growth for example cooler parts of the hot water system or warmer parts of the cold water system

Take samples from the proximal and distal ends of each water system with a locally agreed number of sampling points between.

• The number of samples collected during any single round of sampling should be sufficient to be fully representative of the entire water distribution system.
• The outlets being sampled within clinical facilities should be rotated at each sampling round unless a decision has been made to sample all outlets every time.
• Outlets within ancillary facilities (including those shared by departments) such as staff kitchens, domestic services rooms (DSR), treatment rooms and preparation rooms, should be tested during every round of routine sampling.

Interpretation of routine water testing results

• Responsibilities for receiving and initial interpretation of water results should be agreed by the WSG and included in the WSP. This should include agreed processes for escalation of out of specification results.
• Any test results which are above the agreed microbiological limits should be escalated for attention by the Infection Prevention and Control Doctor and Consultant Microbiologist and the AE (water) where required.
• The clinical risk associated with the sample location should be considered when interpreting results.
• If water test results are above the microbiological limits, the following environmental factors should be reviewed to assist with interpretation of results (the water system’s schematic diagram may support this process):
  • water temperature
  • pH
  • residual disinfectant
  • water softeners
  • water turnover
• Routine water test results should be interpreted as a series of trends (over time) and with an awareness of the systems schematic and current condition.

Sampling results and actions following a non-compliant result (no patient cases)

• If coliforms are identified in a water sample, a repeat sample should be collected and tested to rule out a false positive.
• Whenever pre-flush sample results remain above the microbiological limits, pre- and post-flush samples should be collected to determine if there is a local or systemic contamination. Where post-flush samples remain above microbiological limits, it may indicate systemic contamination. Negative or low post-flush samples may indicate a local contamination (outlet and/or associated pipework and/or fittings near the outlet).
• Taking water samples from further back in the system (beyond the outlet itself) should be considered when positive pre-flush and post-flush sample test results are obtained.
• Following a positive water test result, an immediate review of existing control measures and risk assessment by the IPC team and estates team should be carried out to identify additional remedial/clinical actions required.
• If water continues to test positive following remedial intervention at the outlets, consider taking water samples from further back in the system (beyond the outlet itself).
• Repeat samples should be taken when disinfection/remedial actions have taken place to ensure effectiveness of actions.

Remedial actions following positive water results (no patient cases)

Remedial actions should be agreed by the WSG.

Remedial actions should be determined based on consideration of the water test results in context with the water system as a whole, any existing control measures, and the areas where the result has been obtained.

• When post-flush samples are negative or have low counts, remedial actions should be directed towards the outlet (and associated pipework and fittings).
• When attempting to remove or reduce microbial contamination at the outlet (inclusive of the drain) consider:

• • disinfection (chemical and/or heat treatment),
  • physical replacement of parts of the outlet
  • removal of the entire outlet (including dead-legs)
• If contamination is suspected to extend beyond the outlet (further back in the system) whole system water disinfection may be required.

For more information on whole water system disinfection see  (SHTM 04-01 part D ‘Disinfection of Domestic Water Systems’

 

 

4.1.8 Indications for routine environmental surface sampling

Routine environmental surface sampling may be beneficial in addition to routine water sampling if seeking to determine the extent of environmental contamination.  

Knowledge of environmental sources of contamination can support development of measures to prevent transmission from those sources to patients.

Environmental sources include any sites that are exposed to water.

• When deciding on the need for, and frequency of, routine environmental surface sampling, past incidents or outbreaks may help identify specific locations within the healthcare facility where contamination was previously detected or where relevant patient colonisations and infections occurred. This information allows for targeted sampling in areas that may pose a higher risk of transmission.

Environmental surface sampling can also be used to measure the effectiveness of any decontamination methods in use.

See 4.1.9 incident investigation for information on environmental surface sampling in response to clinical cases.

Actions following environmental surface sampling results 

• Results interpretation should be undertaken by the ICD/microbiologist/IMT. 

• Results may indicate the need to implement or strengthen control measures for example cleaning, decontamination, replacement of equipment/fixtures, and change to clinical practice/patient care. 

4.1.9 Incident investigation

• Preparedness
• Detection of a healthcare-associated infection incident or outbreak
• Investigation
• Water testing in response to clinical cases
• Environmental surface sampling in response to clinical cases
• Closing an incident

Preparedness

The water safety group should have an agreed WSP that covers all care settings and is inclusive of a business continuity/contingency arrangement in preparation for the event that a water source, for example mains water, system water, tap water, cannot be used or an area cannot be used due to widespread known or suspected contamination. 

All high-risk settings should have a setting-specific alert organism list for clinical isolates, which should be informed by the known historical epidemiology of that setting and allow for early identification of single cases of unusual environmental organisms.  

As a minimum, this alert organism list should include 

• Acinetobacter spp.
• Burkholderia spp.
• Chryseomonas indologenes
• Cupriavidus pauculus
• Legionella spp.
• Pseudomonas spp.
• non-tuberculous Mycobacteria (NTM)
• Serratia marcescens
• Sphingomonas spp. 
• Stenotrophomonas maltophilia

See Appendix 13 for more information on alert organisms including the locations/patient cohorts to which each apply. 

Detection of a healthcare-associated infection incident or outbreak

Colonisation or infection of gram-negative microorganisms or non-tuberculous mycobacteria, isolated from a clinical sample in any patient should raise a high degree of suspicion of a healthcare associated environmental link and should be investigated/reviewed.  

An environmental source should be considered when Enterobacteriaceae is isolated from a clinical sample and a data exceedance has been identified. 

Isolation of Legionella spp. from a clinical sample in any patient indicates transmission from the environment and should be investigated as a possible healthcare associated infection incident if the incubation period fits and there is no established link to a community source.  Further information can be found in the NIPCM A-Z of Pathogens for Legionella spp. 

When determining HAI status, the incubation period should be considered, acknowledging the wide variation (a few hours to years) for environmental organisms. 

• The incubation period for environmental organisms, particularly in high-risk groups may be relatively short and may not fit with the routinely applied 48 hour rule. 

• Careful consideration should be applied when assessing an HAI in this category, recognising also that whilst a patient is receiving antibiotics which may assist in selecting the gram-negative organism more readily, it should still be considered and investigated. 

Environmental organism outbreaks and incidents may occur over extended periods of time with significant time between cases. Consideration of an environmental link should be given to cases that have been identified over a wide time period.  

Ensure that the risk of a false negative result is considered and further sampling discussed. This can be supported by taking a measured approach to sampling from the outset.

Investigation

• A multi-disciplinary IMT chaired by the ICD/ Consultant in Public Health Medicine (CPHM) should be established when any water associated infection risk is identified, to support the board and WSG to manage the incident.
• Healthcare water system incidents should be assessed according to the NIPCM healthcare Infection Incident Assessment Tool (HIIAT). For more information see Chapter 3 of the NIPCM.
• The Incident Management Team (IMT) should consider all possible sources including the environment (the water supply itself plus the plumbing components) and patients as both may be sources that can lead to ongoing transmission of waterborne infectious agents to other patients and further contamination of the environment.
• If it is essential for the water outlets to remain in use, point of use (POU) filters should be installed while investigations are ongoing and remedial actions are being considered.

Water testing in response to clinical cases

The IMT should agree a water sampling plan to identify and prioritise potential sources taking account of the following: 

• the local water system for example the wash hand basin/shower in the patient's room 
• mains water supply 
• the layout and schematics of the associated water system 
• water associated equipment and procedures and any other sources of water exposure during patient care 
• the potential involvement of refillable bottles 
• historical water testing results/ trends 
• known epidemiological information (including historical) 
• the geographical distribution of any infected or colonised cases (during their entire healthcare journey) 

Water samples should be taken before disinfection of the water system or equipment or before any other remedial actions are initiated.

As a minimum, a pre-flush sample should be taken from each outlet being sampled. Post-flush samples should also be considered.

Sampling instructions can be found in SHTM 04-01 Part C 

• For sampling guidance specific to Legionella spp., BSI 7592:2022 ‘Sampling for Legionella bacteria in water systems – Code of practice’ should be followed.

Where no UKAS accreditation exists for specific healthcare water system-associated organisms, boards should still consider testing and can seek advice from ARHAI Scotland. See the UKAS Technical Bulletin for more information. 

Environmental surface sampling in response to clinical cases

Environmental surface sampling (swabbing) should be carried out when there is more than one working hypothesis and an environmental source is suspected.

• Consider data exceedance (for example sporadic cases of colonisation or infection over a set time period which might occur over many years).
• An environmental sampling plan should be agreed by the IMT.
• Identify and prioritise potential sources or reservoirs taking account of:
  • epidemiological information (including historical)
  • historical environmental and water sampling results
  • the geographical distribution of the infected and colonised cases throughout their entire healthcare journey
• Environmental sites would include any sites that are exposed to water.
• Environmental samples should be taken before environmental cleaning or decontamination occurs or any other environmental remedial actions have been initiated.

Closing an incident

When considering whether to declare an infection incident or outbreak as ‘closed’ or ‘over’ the IMT should be assured that transmission risks have been mitigated, including exposure from any remaining colonised or infected patients and that there is a surveillance plan in place to allow for early detection of any further potentially linked cases. 

 

Bed spacing

Guidance consistently recognises that bed spacing requirements contribute towards the control of HAIs. All NHS boards and care providers should aim to meet the minimum bed spacing requirements laid out in the guidance below and in keeping with the date of design and construction of the building. This takes account of ergonomics within the clinical environment and not just healthcare associated infection (HAI) risk.  Some other health and care settings may choose to adopt this guidance e.g. hospice settings.

Adult in-patient facilities designed post 2010 should achieve 3.6m (width) x 3.7m (depth) dimensions of SHPN 04-01, HBN 00-03 and SHFN 30.  Width of 3.6m is measured from bed centre to bed centre. Since 2014, HBN 00-03’s Figure 45 states a day treatment bay should achieve 2.45m width/centre-to-centre dimension.

Current NHS Scotland Guidance on bed spacing is listed below:

• Core guidance - General design for healthcare buildings (HBN 00-01)
• Core guidance - Clinical and clinical support spaces (HBN 00-03)
• Critical care units (HBN 04-02)
• HAI-SCRIBE Manual information for project teams (SHFN 30 Part A)
• HAI-SCRIBE Implementation strategy and assessment process (SHFN 30 Part B)
• HAI-SCRIBE question sets and checklists (SHFN 30 Part C)
• Adult in-patient facilities (SHPN 04-01)
• In-patient accommodation - supp 1 - Isolation facilities in acute settings (SHPN 4 sup 1)

 

Clinical Assurance

ARHAI Scotland’s Clinical Assurance programme provides clinical and infection prevention and control (IPC) expertise to complement the work undertaken by the NHSScotland’s Assure (NHSSA) assurance service. More information about the programme and a list of tools and guidance developed is available.

Key Stage Assurance Reviews (KSAR) focus on ensuring infection prevention and control is a key consideration for healthcare construction projects.  ARHAI Scotland have developed notes for NHS Board IPC Teams which aim to help navigate this process.    

• Notes for Board IPC Teams document to navigate the KSAR process     

 

Publications

Work undertaken and published to date has been cited here for ease of reference and use at a clinical level.

Many of these publications were produced prior to development of chapter 4 and were published outwith the existing manual methodology.

Updates to publications will be made where required as part of the ARHAI programme work plans.  

ARHAI Scotland will work with SG directorates responsible for these areas in planning to establish planned implementation.

Decontamination

• NHSScotland Guidance for decontamination of semi-critical ultrasound probes
• NHSScotland Guidance for Decontamination and testing of Cardiac Heater Cooler Units (HCUs). v1.0 | National Services Scotland

Alternative approaches to decontamination

• Literature Review and Practice Recommendations: Existing and emerging technologies used for decontamination of the healthcare environment
  • Antimicrobial Copper Surfaces
  • Antimicrobial Copper and Silver Solutions
  • ATP Bioluminescence and Fluorescent Markers (v2.0, June 2023)
  • Chlorine Dioxide
  • Electrolysed Water
  • HINS Light
  • Hydrogen Peroxide
  • Microfibre
  • Ozone
  • Steam
  • UV light (v2.0, November 2022)
  • Wipes (v2.0, December 2022)

Built environment

• NHSScotland Guidance for the interpretation and clinical management of endoscopy rinse water
• Literature Review and Recommendations: Management of Dental Unit Waterlines