HTM0401 Addendum P.aeuginosa

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Water systemsHealth Technical Memorandum04-01: Addendum

Pseudomonas aeruginosa advice for augmentedcare units


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DH INFORMATION READER BOX

ClinicalCommissioner Development IM & T

Provider Development Finance

Improvement and Efficiency Social Care / Partnership Working

Estates

Best Practice Guidance

PolicyHR / Workforce

Management

Planning / Performance

Document Purpose

Gateway Reference 18520

Title HTM 04-01 - Addendum: Pseudomonas aeruginosa advice for

augmented care units

Author DH, Estates & facilities

Publication Date March 2013

Target Audience NHS Trust CEs, Care Trust CEs, Foundation Trust CEs , Medical

Directors, Directors of PH, Directors of Nursing, Allied HealthProfessionals, Communications Leads, Emergency Care Leads

Circulation List PCT Cluster CEs, SHA Cluster CEs

Description This addendum, aimed at all those involved with patient safety and

specifically estates and facilities and infection prevention and control

teams, focuses on specific additional measures to control/minimise therisk of P. aeruginosa. It may also have relevance to other opportunistic

pathogens such as Stenotrophomonas maltophilia, Burkholderia cepacia

and atypical mycobacteria.

Cross RefN/A

Superseded Docs Water sources and potential Pseudomonas aeruginosa contamination of

taps and water systems Advice for augmented care units

Action RequiredN/A

Timing N/A

Contact Details

For Recipient's Use

Phil Ashcroft

Estates & Facilities

Quarry HouseQuarry Hill

LS2 7UE

01132 545620

0


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Water systems

Health Technical Memorandum 04-01:AddendumPseudomonas aeruginosa advice or augmented care units

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Health Technical Memorandum 04-01 Addendum: Pseudomonas aeruginosa advice for augmented care units

You may re-use the text of this document (not including logos) free of charge in any format or medium,under the terms of the Open Government Licence. To view this licence, visitwww.nationalarchives.gov.uk/doc/open-government-licence/

Crown copyright 2013Published in electronic format only.

The Department of Health would like to thank all those who have helped to develop and produce thisguidance, including all those who commented and sent contributions during the technical engagementphase.

Photography by Zak Prior
http://www.nationalarchives.gov.uk/http://www.nationalarchives.gov.uk/doc/openhttp://www.nationalarchives.gov.uk/doc/openhttp://www.nationalarchives.gov.uk/http://www.nationalarchives.gov.uk/doc/openhttp://www.nationalarchives.gov.uk/doc/open


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Contents

Executive summary ivGlossary and list o abbreviations v

Chapter1 Introduction 1

Chapter2 Pseudomonas aeruginosa: overview 2Ecology 2

Transmission 2Source 2

Management o control 3

Chapter3 Design and selection o water outlets and fttings 4

Chapter4 Operational management 6Introduction 6

The Water Saety Group 6

Water saety plans (WSPs) 7

Protecting augmented care patients 10Sampling and testing orP. aeruginosa 11

What to do i a contamination problem is identifed 14

Appendix 1 Best practice advice relating to allclinical wash-hand basins in healthcare acilities 17

Appendix 2 Types and method o operation otaps and TMVs 18

Appendix 3 Water sampling 19

Appendix 4 Microbiological examination owater samples orP. aeruginosa 21

Appendix 5 Example o a typical risk assessment toinorm the WSP or augmented care units 25

Appendix 6 ExemplarP. aeruginosasample sheet 27

Reerences 28

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iv


Executive summary

In recent years there has been an increase inpublished evidence relating to outbreaks andincidents in augmented care units related toPseudomonas aeruginosa.

In March 2012, the Department of Health publishedWater sources and potential Pseudomonas aeruginosacontamination of taps and water systems: advice foraugmented care units. This addendum to HealthTechnical Memorandum 04-01 builds on and

supersedes the March 2012 guidance.

The document is concerned with controlling/minimising the risk of morbidity and mortality dueto P. aeruginosaassociated with water outlets andprovides guidance on:

assessing the risk to patients when water systems become contaminated with P. aeruginosaor other opportunistic pathogens;

remedial actions to take when a water systembecomes contaminated with P. aeruginosa;

protocols for sampling, testing and monitoringwater for P. aeruginosa; and

forming a Water Safety Group (WSG) and developing water safety plans (WSPs).

The guidance is directed towards healthcareorganisations providing patient care in augmentedcare settings. It is specifically aimed at Estates andFacilities departments and infection prevention andcontrol (IPC) teams.

For the purposes of this document, the patientgroups in an augmented care setting include:

a. those patients who are severely

immunosuppressed because of disease ortreatment: this will include transplant patientsand similar heavily immunosuppressed patientsduring high-risk periods in their therapy;

b. those cared for in units where organ support isnecessary, for example critical care (adultpaediatric and neonatal), renal, respiratory(may include cystic fibrosis units) or otherintensive care situations;

c. those patients who have extensive breaches intheir dermal integrity and require contact with

water as part of their continuing care, such asin those units caring for burns.


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Glossary and list o abbreviations

GlossaryAlert organisms:Alert organisms aremicroorganisms that have the potential to causeharm and disease in individuals and which can causean outbreak of infection in a hospital environment.

An alert organism is identified by the microbiologylaboratory and referred to the infection preventionand control (IPC) team for assessment of possible

healthcare-associated acquisition and to identify anypossible environmental/equipment sources.

Augmented care units/settings: There is no fixeddefinition of augmented care; individual providersmay wish to designate a particular service as one

where water quality must be of a highermicrobiological standard than that provided by thesupplier. While this document provides broadguidance, the water quality required will bedependent on both the type of patient and its

intended use. Most care that is designated asaugmented will be that where medical/nursingprocedures render the patients susceptible to invasivedisease from environmental and opportunisticpathogens such as Pseudomonas aeruginosaand otheralert organisms. In broad terms, these patient groups

will include:

a. those patients who are severelyimmunosuppressed because of disease ortreatment: this will include transplant patients

and similar heavily immunosuppressed patientsduring high-risk periods in their therapy;

b. those cared for in units where organ support isnecessary, for example critical care (adultpaediatric and neonatal), renal, respiratory(may include cystic fibrosis units) or otherintensive care situations;

c. those patients who have extensive breaches intheir dermal integrity and require contact with

water as part of their continuing care, such as

in those units caring for burns.

Biofilm:A biofilm is a complex layer ofmicroorganisms that have attached and grown on asurface. This form of growth provides a nicheenvironment for a wide range of microorganisms tointeract and where the secretion ofexopolysaccharides by bacteria will form anextracellular matrix for both bacteria and otherunicellular organisms such as amoebae and flagellates

to remain in a protected state.Blind end (or dead end): A length of pipe closed atone end through which no water passes.

Colony forming unit: Unit that gives rise to abacterial colony when grown on a solid medium; thismay be a single bacterial cell or a clump of cells.

Dead-leg: A pipe supplying water to a fittingthrough which water flows only when there is draw-off from the fitting.

Estates and Facilities management: This titleembraces the healthcare facilities themselves and theengineering and many other services containedtherein. Maintenance and management of thebuildings and engineering services is often referred toas hard FM (facilities management); activities suchas catering, cleaning, sterile supply services, laundryand linen supply is often referred to as soft FM.

Flow straightener: A device inserted into the spoutoutlet of a tap to modify flow, take out turbulence

and create an even stream of water (see photographbelow).

Point-of-use filter: A device comprising a filter

membrane that is fitted to water outlets such as tapsand showers at the point of water delivery to retainbacteria.

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Remediation: Any process that reduces the risk fromharmful agents such as microorganisms.

Transmission: Any mechanism by which an

infectious agent is spread from a person orenvironmental source to a susceptible person.

Water outlet: (In this document) refers mainly totaps and showerheads, but other outlets, as indicatedby risk assessments, may be considered important.

Water Safety Group (WSG): A multidisciplinarygroup formed to undertake the commissioning anddevelopment of the water safety plan (WSP). It alsoadvises on the remedial action required when watersystems or outlets are found to be contaminated and

the risk to susceptible patients is increased.

Water safety plan (WSP): A risk-managementapproach to the microbiological safety of water thatestablishes good practices in local water distributionand supply. It will identify potential microbiologicalhazards caused byP. aeruginosaand otheropportunistic pathogens, consider practical aspects,and detail appropriate control measures. WSPs are

working documents that need to be kept up-to-dateand reviewed whenever organisations make changes

to water supplies, uses of water and controlmeasures.

Water supply [to the hospital]: The water suppliedcan be via:

the mains water supply from the local waterundertaker (water company);

a hospital borehole; a combination of mains water and borehole

supply; emergency water provision (bulk tankered

water or bottled drinking water).

List o abbreviationscfu: colony forming units

DIPC: director of infection prevention andcontrol

HCAI Code of Practice: The Health and SocialCare Act 2008: Code of Practice on theprevention and control of infections and relatedguidance

IPC: infection prevention and control

MCA: milk cetrimide agar

MRD: maximum recovery diluent

PFI: private finance initiative

PHE: Public Health England

POU: point-of-use

TMV: thermostatic mixing valve

WRAS: Water Regulations Advisory Scheme

WSG: Water Safety Group

WSP: water safety plan

For definition of taps/TMVs, seeAppendix 2.

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1.0Introduction

1.1 This addendum to Health TechnicalMemorandum 04-01 is aimed at those involved withpatient safety and specifically Estates and Facilitiesand infection prevention and control (IPC) teams.

1.2 It focuses on the specific additional measures tocontrol/minimise the risk ofP. aeruginosa, but mayalso have relevance to other opportunistic pathogenssuch as Stenotrophomonas maltophilia, Burkholderiacepaciaand atypical mycobacteria.

1.3 The recommendations for the control ofLegionellaetc given in Health TechnicalMemorandum 04-01 remain extant.

1.4 Additional general requirements for the qualityassurance of water systems including those withinhealthcare facilities should be followed (see theHealth & Safety Executives Legionnaires disease:the control of legionella bacteria in water systems

Approved Code of Practice and guidance and theNHS Premises Assurance Model).

Chapter 1 Introduction

NHS Premises Assurance ModelThe NHS has developed, with the support of theDepartment of Health, the NHS Premises

Assurance Model (NHS PAM), whose remit is toprovide assurance for the healthcare environmentand to ensure service-users are protected againstrisks associated with such hazards as unsafepremises.

It allows NHS organisations to better understandthe effectiveness, quality and safety with whichthey manage their estate (including water safety)and how that links to the patient experience.

NHS PAM has been designed to apply to:

NHS foundation trusts; NHS trusts; mental health trusts; ambulance trusts; and community trusts.

For more information on how to use the tool,visit http://www.dh.gov.uk/health/2013/01/nhspam

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2.0 Pseudomonas aeruginosa:

overview

Ecology2.1 P. aeruginosais a Gram-negative bacterium,commonly found in wet or moist environments. It iscommonly associated with disease in humans withthe potential to cause infections in almost any organor tissue, especially in patients compromised by

underlying disease, age or immune deficiency (seeparagraph 2.3). Its significance as a pathogen isexacerbated by its resistance to antibiotics, virulencefactors and its ability to adapt to a wide range ofenvironments.

2.2 P. aeruginosathrives in relatively nutrient-poorenvironments at a range of different temperaturesand can become one of the species in biofilms wherea slime layer binds a mixed bacterial population tosurfaces. Although most bacteria will remain fixed

within the biofilm, some will become detachedresulting in free-floating (planktonic) forms that cancause contamination of the water layer above thebiofilm.

Transmission2.3 P. aeruginosais an opportunistic pathogen thatcan colonise and cause infection in patients who areimmunocompromised or whose defences have beenbreached (for example, via a surgical site,

tracheostomy or indwelling medical device such as avascular catheter). In most cases, colonisation willprecede infection. Some colonised patients willremain well but can act as sources for colonisationand infection of other patients. As a microorganismthat is often found in water, the more frequent thedirect or indirect contact between a susceptiblepatient and contaminated water, and the greater themicrobial contamination of the water, then thehigher the potential for patient colonisation orinfection.

2.4 Contaminated water in a hospital setting cantransmit P. aeruginosato patients through thefollowing ways:

direct contact with the water through: ingesting

bathing

contact with mucous membranes or surgical

site, or through splashing from water outlets or

basins (where the flow from the outletcauses splashback from the surface);

inhalation of aerosols from respiratoryequipment, devices that produce an aerosol oropen suctioning of wound irrigations;

medical devices/equipment rinsed with contaminated water;

indirect contact via healthcare workers handsfollowing washing hands in contaminated

water, from surfaces contaminated with wateror from contaminated equipment such asreusable wash-bowls.

Source2.5 It is generally accepted in the case ofLegionellathat the source of bacteria in hot- and cold-watersystems is the incoming water supply and that itbecomes a problem only if there is a failure of therecommended control measures (for example,maintenance of temperatures or water treatmentregimens).

2.6 In contrast to Legionella, the origin ofP. aeruginosais less certain. Its presence becomesevident at outlets from the system (for example taps)and can be found within the last two metres beforethe point of discharge of water. Devices fitted to, orclose to, the tap outlet (for example flow

straighteners) may exacerbate the problem byproviding the nutrients which support microbialgrowth, providing a surface area for oxygenation of


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water and leaching nutrients. The source, therefore,could be:

the incoming water supply from the water provider;

the water supply within the building (bothfrom the storage and distribution system),usually within biofilms;

the waste-water system (see Breathnach et al.2012); or

via external contamination from: clinical areas

outlet users

poor hygiene or processes during cleaning

splashback from contaminated drains.

2.7 Given this variety, the challenge for managersand staff is to risk-assess their particular operationalpractices in an attempt to minimise inoculation fromany of these sources.

Management o control2.8 Management of water systems to reduce the riskof microbial growth including opportunisticpathogens such as Legionellaand P. aeruginosais vitalto patient safety. It requires surveillance andmaintenance of control measures includingtemperature control, usage, cleaning and disinfectionmeasures as identified within the risk assessment andLegionellacontrol scheme for both hot- and cold-

water systems.

2.9 To prevent growth ofP. aeruginosa, controls arenecessary to manage the water system before andafter the outlet (comprehensive advice is given inChapter 4).

Chapter 2 Pseudomonas aeruginosa: overview

2.10 Estates and facilities staff should ensure accuraterecords and drawings/diagrams showing the layoutand operational manuals of the whole water systemare available. These staff should have receivedadequate training and be fully aware of the extent oftheir responsibilities. Strict adherence to therecommendations in Health TechnicalMemorandum 04-01 will help to achieve this (seeChapter 4).

2.11 IPC teams should:

ensure application of, and compliance with, theevidence-based guidelines for preventinghealthcare-associated infections in NHS

hospitals in England (see Pratt et al. (2007));

ensure best practice advice relating to wash-hand basins is followed to minimise the risk ofP. aeruginosacontamination (seeAppendix 1).

2.12 The Health and Social Care Act 2008: Code ofPractice on the prevention and control of infectionsand related guidance (the HCAI code of Practice)sets out the criteria against which a registeredproviders compliance with the requirements relatingto cleanliness and infection control will be assessed

by the Care Quality Commission. It also providesguidance on how the provider can interpret andmeet the registration requirement and comply withthe law. Criterion 2 states that providers shouldprovide and maintain a clean and appropriateenvironment in managed premises that facilitates theprevention and control of infections.

2.13 IPC teams should continue to monitor clinicalisolates ofP. aeruginosain risk-assessed augmentedcare units as an alert organism and be aware of

possible outbreaks or clusters of infection with thismicroorganism.

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3.0 Design and selection o water

outlets and ittings3.1With the change in focus towards improving thepatient environment and minimising the risk ofhealthcare-associated infections, there has been anincrease in the provision of single-bed rooms withen-suite facilities. Additionally, to promote goodhand hygiene, wash-hand basin provision hasincreased significantly in all clinical areas. However,

in many situations this has led to underused wateroutlets and low water throughput. Such outlets forma greater risk of contamination byP. aeruginosathanthose that are used more frequently.

3.2Water services have become more complex.Every effort should be made when planning,designing and installing new or modified systems tominimise and remove potential hazards (for exampleoversized water storage tanks, flexible hoses, stagnant

water, poor temperature control, long branch pipes

and dead-legs), as well as enabling access formonitoring and maintenance. Adapting existingsystems to improve safety is almost always the moreexpensive solution.

3.3 In new and existing premises, therefore, it isessential that the needs of individual patient washingand bathing requirements are carefully considered. Innew premises, the provision, correct siting andinstallation of showers and wash-hand basins,particularly in accommodation where patients are

unlikely to make use of them, requires assessment.For existing premises, and subject to a riskassessment, permanent removal of existing outletsand their associated pipework should be considered.

3.4 Tap design has evolved. In older installations,thermostatic control of water temperature wasachieved by a separate thermostatic mixing valve(TMV) (commonly called a t-shaped TMV),typically located behind the sanitary assembly panelto which a wash-hand basin or other assembly was

fitted, which then supplied water to the hotconnection of a manual mixing tap or separate tap(see Figure 4). Many new installations now include

are usually manually controlled (on and off) and canbe adjusted to further reduce outlet temperature tofully cold. For some applications, remote sensor-operated taps are available (many sensor taps alsohave the option of auto-flushing programmes andcan be linked to the hospitals building managementsystem). In some instances these developments have

led to a more complicated internal tap design whichmay increase the need for additional routinemaintenance (including decontamination) tomitigate the risk of contamination byP. aeruginosa.

3.5 The choice and type of water outlets for theaugmented care setting is therefore important (see

Appendix 2). This choice should be based on a riskassessment of infection-control and scalding issues.

3.6 There is some evidence that the more complexthe design of the outlet assembly (for example, somesensor-operated taps), the more prone toP. aeruginosacolonisation the outlet may be (seeBerthelot et al. 2006).

3.7 In intensive care and other critical care areas,where patients are unlikely to be able to use thewash-hand basins, the installation of non-TMVmixing taps may be the preferred control optionfollowing a risk assessment (see paragraph 1 in

Appendix 2).

Note:

For clinical wash-hand basins, Health BuildingNote 00-10 Part C Sanitary assemblies(formerly Health Technical Memorandum 64)recommends integral thermostatically controlled

water using either a single-lever tap or a sensortap for most applications and settings. If riskassessment justifies a different tap assembly forclinical wash-hand basins in augmented caresettings, then derogation from Health Building

Note 00-10 Part C may be considered so long asit is approved by the Water Safety Group (WSG).

taps of a modern design with integral TMVs. They


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Chapter 3 Design and selection o water outlets and fttings

3.8 In accordance with Health TechnicalMemorandum 04-01 Part A, TMVs should be fitted

where risk assessment has shown vulnerable patientsare at risk of scalding. This should be considered

when planning/designing new builds orrefurbishments. A TMV that is integral to the bodyof the tap/shower is preferred, as it is designed toalways draw cold water through every time the outletis used, thus helping to minimise the risk ofstagnation.

Note:

Scalding risk assessments should form part of thewater safety plan (WSP) before any decision is

made on the method of scalding risk control (seeparagraphs 4.114.26).

3.9 Owing to their high surface-area-to-volume ratioand location at the tap outlet, certain designs of flowstraightener may present a greater surface area forcolonisation and support the growth of organisms.Therefore, when selecting new taps, where possibleflow straighteners should be avoided/not included.Health Building Note 00-09 also advises againstusing aerators in outlets.

3.10 If retro-fitting new taps, it is important toensure that they are easy to use and practical for theexisting space.

3.11 For guidance on replacing taps, see paragraph4.49(k).

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4.0 Operational management

Note:

This addendum focuses on the specific additionalmeasures to control/minimise the risk ofP. aeruginosa, but may also have relevance to other opportunistic pathogens such as Stenotrophomonas maltophilia, Burkholderiacepaciaand atypical mycobacteria. Therecommendations for the control ofLegionella

given in Health Technical Memorandum 04-01remain extant; however, the operationalmanagement processes outlined in thisaddendum may also assist in the implementationof Health Technical Memorandum 04-01 Part B.

Introduction4.1 Healthcare organisations have an explicit dutyunder the Health and Safety at Work Act etc 1974 toassess and manage the risks posed by water systemson their premises. In accordance with the HCAICode of Practice, the healthcare organisations chiefexecutive is responsible for having systems in place tomanage and monitor the prevention and control ofinfection. These systems use risk assessments andconsider how susceptible patients are, and any risksthat their environment and other users may pose tothem. Ensuring these elements are in place will assistthe organisation to fulfil its duties in relation to theprovision of safe water systems. A programme of

audit should be in place to ensure that key policiesand practices are being implementedappropriately. This will inform the organisationsassurance framework.

The Water Saety Group4.2 The WSG is a multidisciplinary group formed toundertake the commissioning and development ofthe WSP. It also advises on the remedial actionrequired when water systems or outlets are found tobe contaminated and the risk to susceptible patientsis increased. The WSG may be a sub-group of theorganisations infection control committee or otherrelevant forum and could typically comprise:

the director of infection prevention and control(DIPC);

the IPC team; consultant medical microbiologist; the Estates and Facilities team (including hotel/

cleaning services staff and the ResponsiblePerson (Water));

senior nurses from relevant augmented careunits.

The chair of the group will be a local decision.

4.3 Irrespective of who chairs the group, they will beresponsible for ensuring it identifies microbiologicalhazards, assesses risks, identifies and monitorscontrol measures, and develops incident protocols.

4.4 Episodes of colonisation or infection withP. aeruginosathat could be related to the watersystem should be reported by the IPC team to the

chair of the WSG, who will be expected to initiatean appropriate investigation.

4.5 The WSG should always act in an appropriateand timely manner. Individual responsibilities shouldnot be restricted by the need to hold formalmeetings.

4.6 As part of its wider remit, the WSG shouldinclude representatives from areas where water maybe used in therapies, medical treatments ordecontamination processes (for example,

hydrotherapy, renal, sterile services).

Assurance/governance4.7 The WSG should be accountable to the DIPCand provide reports upwards, for example to theinfection control committee (although it isacknowledged that accountability arrangements forthe WSG will vary by healthcare provider).Irrespective of the route the healthcare providerdecides, it is important that accountability should

demonstrate effective governance and assurance.4.8 The WSG should monitor any proposeddevelopments on the design or installation of the

water distribution system and check that they are:
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likely to minimise the risk to patients, especially those treated in augmented care settings;

compliant with all extant legislation and DHpolicy and guidance.

4.9 All items of equipment that need to be attachedto the water distribution system and which may beused in direct care on patients should be approved bythe WSG.

4.10 The WSG will need to ensure that decisionsaffecting the safety and integrity of the water systemdo not go ahead without being agreed by them.

Note:

Where estates & facilities provider services arepart of a contract (including PFI), it is essentialthat these providers participate fully in all aspectsof estate & facilities management that can affectpatients. This includes responding to specificrequests from the IPC team and WSG, whichmay be in addition to relevant guidance anddocumentation.

Water saety plans (WSPs)4.11 To assist with understanding and mitigatingrisks associated with bacterial contamination of

water distribution and supply systems and associatedequipment, healthcare providers should develop a

WSP, which provides a risk-management approachto the microbiological safety of water and establishesgood practices in local water usage, distribution andsupply (see Figure 1). Those organisations with

existing robust water management policies forLegionellawill already have in place much of theintegral requirements for developing a WSP.

4.12 The first step in the development of a WSP isto gain a comprehensive understanding of the watersystem, including the range of potential hazards,hazardous events and risks that may arise duringstorage, delivery and use of water. It may require anunderstanding of the quality and management of the

water as provided and how that water is used.Fundamental to this and any subsequentinvestigation or review is the provision andavailability of accurate records/schematic drawings.

Chapter 4 Operational management

4.13With respect to P. aeruginosa, the WSP shouldidentify areas within hospitals with at-risk patientsand incorporate:

clinical risk assessment to identify those settingswhere patients are at significant risk fromP. aeruginosacontamination associated with

water use and its distribution system;

an engineering risk assessment of the watersystem;

operational monitoring of control measures; links to clinical surveillance which can offer an

early warning of poor water quality;

plans for the sampling and microbiologicaltesting of water in identified at-risk units (see

Appendices 3 and 4).

Note:

Appendix 4 has been developed to provide technical guidance for a range of laboratories, including NHS, Public Health England (PHE) and commercial laboratories that have the capability and capacity to undertake water

sampling and testing.

changes to the water system to remedy highcounts for P. aeruginosaand other opportunisticpathogens where appropriate;

adjustments to clinical practice until remedialactions have been demonstrated to be effective;

regular removal/cleaning/descaling orreplacement of the water outlets, hoses and

TMVs where there may be direct or indirectwater contact with patients (see HealthTechnical Memorandum 04-01);

amendments when changes are carried out andat annual review, including new builds,refurbishments and recently decommissionedclinical departments or units;

documentation and record-keeping (bestpractice examples of the types of documentationand record keeping required are given in Health

Technical Memorandum 04-01); a review of the results of any water testing

regimen undertaken.

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Figure 1 Documentation o management procedures (adapted rom Figure 4.1 in WHOs Water saety inbuildings)

Identification of potential hazards

Assess and prioritise risks

Determine existing control measures

Identify additional or improved control measures

System risk assessments

Identification of potential hazards

Define corrective actions

Implement and maintain monitoring andcontrol measures

Controlling risks

Verification and auditing

Description of water system

Supportivetrainingand

reviewp

rogrammes

Periodicrevie

w(atleastannually

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4.14 The WSP should identify potential alertorganisms and microbiological hazards caused byLegionella, P. aeruginosaand other opportunisticpathogens, consider practical aspects and detailappropriate control measures. The implementationof the WSP should be coordinated by theResponsible Person (Water). Implementation statusreports should be periodically submitted to the

WSG.

4.15 Development of the WSP will complement theexisting operational management requirements ofHealth Technical Memorandum 04-01 and the workthat has to be undertaken to fulfil the statutoryrequirement for aLegionellarisk assessment and

written scheme for its control and management.

4.16 The multidisciplinary group that developed theWSP also has a role in advising on the remedialaction and communication required, should one ormore outlets be found to be contaminated and wherethis may increase the risks to susceptible patients (seeparagraph 4.49).

4.17WSPs are working documents that need to bekept up-to-date and reviewed at least annually by the

WSG and whenever incidents occur or organisationsmake changes to:

water supplies and uses; control measures; its risk-management policies.

Risk assessments4.18 The risk assessments that inform the WSPshould identify potential microbiological hazards

caused byP. aeruginosaand other opportunisticpathogens, and the hazardous events and risks thatmay arise during storage, delivery and use of water inaugmented care settings.

4.19 They should identify actions to minimise theserisks and ensure that appropriate sampling,monitoring and clinical surveillance arrangementsare in place.

4.20 Risk assessments should be led by the DIPC, aconsultant microbiologist or the IPC team

representative and should consider:

the susceptibility of patients from each type ofwater use (including ice);

scalding risk; clinical practice where water may come into

contact with patients and their invasive devices;

the cleaning of patient equipment; the disposal of blood, body fluids and patients

wash-water;

the maintenance and cleaning of wash-handbasins and associated taps, specialist baths andother water outlets;

change in use (for example, clinical areachanged to office accommodation or vice-versa)due to refurbishment or operational necessity;

other devices that increase/decrease thetemperature of water (for example, ice-makingmachines, water chillers) which may not beappropriate in augmented care settings;

engineering assessment of water systems,including correct design installation,commissioning, maintenance and verificationof the effectiveness of control measures (seealso the Water Supply (Water Fittings)Regulations);

underused outlets; flushing policy; the unnecessary use of flexible hoses and any

containing inappropriate lining materials;

sampling, monitoring and testing programmethat needs to be put in place;

the need for outlets at wash-hand basins thatuse sensor operation and TMVs (remote/

integral);

education and training.4.21 Although not under the category of augmentedcare, situations will arise where surgical wounds maybecome contaminated from water outlets such asshowers. Similarly the practice of soaking leg ulcersor syringing ears may require consideration of themicrobiological quality of water used and willrequire local assessment.

4.22 The likelihood of hazardous events isinfluenced by the size and complexity of the watersystem and can be exacerbated by poor or over

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complicated design, construction, commissioning,operation and maintenance (see Chapter 3).

4.23 Once potential hazards and hazardous events

have been identified, the severity of risk needs to beassessed so that priorities for risk management can beestablished. The risk assessment needs to considerthe likelihood and severity of hazards and hazardousevents in the context of exposure (type, extent andfrequency) and the vulnerability of those exposed.

Although many hazards may threaten water quality,not all will represent a high risk. The aim should beto distinguish between high and low risks so thatattention can be focused on mitigating risks that aremore likely to cause harm to susceptible patients

who are experiencing augmented care (seeAppendix5 for an example risk assessment).

Action plan4.24When the risks have been identified, an actionplan needs to be developed with defined roles andresponsibilities, and agreed timescales to minimisethese risks. The action plan should include:

appropriate remedial actions, monitoringdetails and schedules for validation that showthe remedial actions are effective and subject toongoing verification. Completion dates shouldbe defined.

any training and competency issues required toensure compliance with this guidance.

Documentation4.25 All records pertaining to the risk assessmentand action plan should be held and managed by the

WSG.

Management o water saety risks and issues4.26 Identified water safety risks and issues shouldbe assessed, prioritised and included on a risk registerfor discussion and management by the WSG.

Protecting augmented care patients4.27 The following paragraphs give examples of bestpractice advice aimed at protecting the susceptible

patient and ensuring a safe environment:a. For direct contact with patients, water of a

known satisfactory quality should be used, thatis:

(i) water where testing has shown absence ofP. aeruginosa; or

(ii) water supplied through a point-of-use

(POU) filter; or

(iii) sterile water (for example, for skin contactfor babies in neonatal intensive care units).

b. Water outlets should be reviewed where theremay be direct or non-direct contact withpatients. This may also include reviewing theneed for the outlets/showers and their potentialremoval.

c. For patient hygiene, single-use wipes should be

considered.

d. Rigorous reinforcement of standard infectioncontrol practices, including refresher training,should be implemented.

e. The cleaning of clinical wash-hand basins andthe taps should be undertaken in a way thatdoes not allow cross-contamination from abacterial source to the tap (seeAppendix 1) .

f. The cleaning of patient contact equipment (forexample, tap handles, incubators, humidifiers,nebulisers and respiratory equipment) shouldbe reviewed. Options would be to:

(i) use single-use equipment;

(ii) if locally reprocessed even if used on thesame patient clean equipment with

water of a known satisfactory quality (see (a)above);

(iii) use single-use detergent wipes for cleaningincubators. If a disinfectant is used, it isimportant that it will not cause damage tothe material of the incubator.Manufacturers instructions should befollowed. Disinfectants should not be usedto clean incubators while occupied.

g. All other uses of water on augmented care unitsshould be considered (for example, the use ofice machines, drinking water fountains, bottled

water dispensers, wet shaving of patients whohave a central venous catheter inserted into thejugular vein and washing patients withindwelling devices) and appropriate action/changes to operational procedures taken.


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Notes:

1. Tap water should not be used in neonatalunits for the process of defrosting frozen breastmilk.

2. Water features should not be installed inaugmented care units.

h. All patient equipment should be stored clean,dry and away from potential splashing with

water.

i. All preparation areas for aseptic procedures anddrug preparation and any associated sterile

equipment should not be located where theyare at risk of splashing/contamination from

water outlets.

j. All taps that are used infrequently onaugmented care units should be flushedregularly (at least daily in the morning for oneminute). If the outlet is fitted with a POUfilter, the filter should not be removed in orderto flush the tap unless the manufacturersinstructions advise otherwise. A record should

be kept of when they were flushed. Some tapscan be programmed to flush automatically;such flushing may be recorded on the buildingmanagement system.

k. TMVs and associated components should beserviced, including descale anddecontamination, at recommended intervals(see the TMV approval scheme at http://www.buildcert.com/tmv3.htm).

l. A TMV that is integral to the body of the tap/shower should be considered, as it will alwaysdraw cold water through every time the outletis used, thus helping to minimise the risk ofstagnation.

m. Where taps are designed to be easilyremoved for maintenance purposes, theyshould be periodically removed for descalingand decontamination and/or placed in a

washer-disinfector (subject to the tap

manufacturers instructions).


n. It should be ensured that:

(i) accurate records and drawings cover all thehot- and cold-water systems and that they

have been updated following anymodification;

(ii) all services are properly labelled such thatthe individual services can be easilyidentified;

(iii) staff who are engaged in the installation,removal and replacement of outlets andassociated pipework and fittings are suitablytrained to prevent contamination of the

outlet and water system.

Sampling and testing orP. aeruginosa

Note:

Experience to date has shown no meaningful correlation between the presence and count of P. aeruginosaand total viable counts (TVC) ofbacteria. Consequently, the determination ofTVC need not be done routinely in parallel withtesting for P. aeruginosa.

P. aeruginosain the water supply4.28 P. aeruginosamay be present within the waterstorage, distribution and delivery systems and also inthe water supplied to the hospital.

4.29 The sampling protocol (Appendix 3) isintended to help healthcare providers establish

whether the water in augmented care units iscontaminated with P. aeruginosaand, if it is, to help

locate its origin and to monitor the efficacy ofremedial measures.

4.30 Biofilms exist on plumbing materialsthroughout the water system. Where present, mostP. aeruginosawill be found within two metres of thepoint of water delivery at the outlet that is, afterthe water has left the circulation system.

4.31While most bacteria are trapped within abiofilm, the biofilm will constantly generate bacteriathat are released as free-floating individual cells(planktonic forms), and parts of the biofilm mayslough off in clumps. The concentration of theseplanktonic bacteria will build up over time in the

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water adjacent to a biofilm when the water is of alow flow rate or stagnant, but will be diluted as wateris used and flows through the pipework or tapcontaining the biofilm.

4.32 It is essential to maximise the recovery of thesefree-floating planktonic bacteria that cause infection;therefore, water samples should be taken:

a. during a period of, preferably, no use (at least2 hours or preferably longer); or

b. low use.

4.33 The same water outlet can give very differentresults if sampled at times of normal use and may be

negative if water from the tap has been used before asample is collected.

4.34 The first water to be delivered from the outlet(pre-flush sample) should be collected to assess themicrobial contamination in the outlet.

4.35 If water flows over a biofilm containingP. aeruginosalocated at or near the outlet, planktonicbacteria arising from that biofilm will be diluted anda subsequent sample will give low bacterial counts. Ifcontamination is upstream in the system, this will

not affect bacterial counts.

4.36 The sample obtained after allowing water toflow from an outlet is referred to as a post-flushsample (see paragraphs 12 and 13 in Appendix3). Comparison of counts from pre- and post-flushsamples can help locate the source of theP. aeruginosa. If a pre-flush sample gives a highcount, subsequent paired pre- and post-flush samplesshould be tested to help locate the source of thecontamination.

4.37 In order to be able to carry out the appropriatemicrobiological examinations on a sample andprovide a meaningful interpretation of test results, itis essential that samples are collected in the correctmanner using the correct equipment and that thesampling protocol inAppendix 3 is adhered to.

4.38 Protocols for microbiological examination ofsamples are provided inAppendix 4.

Where to sample water outlets4.39 The water outlets to be sampled should bethose that supply water which:

has direct contact with patients;

is used to wash staff hands; or used to clean equipment that will have contact

with patients as determined by risk assessment.

When and how to sample water outlets4.40 The outlets identified above should be sampledto provide an initial assessment of contaminationlevels. There is no need to sample all taps that aredue to be sampled on the same occasion; samples canbe taken in batches on separate occasions. It mayassist the receiving laboratory if the samplingschedule is agreed beforehand (see Figure 2 and also

Appendix 3).

Interpretation o P. aeruginosatest results4.41 If test results are satisfactory (not detected),there is no need to repeat sampling for a period of sixmonths unless there are changes in the waterdistribution and delivery systems components orsystem configuration (for example, refurbishmentsthat could lead to the creation of dead-legs) oroccupancy.

4.42Water sampling could be undertaken within sixmonths if there are clinical evidence-based suspicions

that the water may be a source of patientcolonisation or infection (that is, with P. aeruginosaor another potentially water-associated pathogen).

4.43 If tests show counts of 110 cfu/100 mL, referto the WSG, who should risk-assess the use of waterin the unit. Simultaneously, retesting of the wateroutlet should be undertaken (see Figure 2 and Notebelow).

4.44 If test results are not satisfactory (>10 cfu/100 mL), further sampling along with an engineeringsurvey of the water system could be used to identifyproblem areas and modifications that may beimplemented to improve water quality.

4.45 After such interventions, the water should beresampled (see Figure 2 for suggested frequencies).

Note:

Figure 2 gives an example of samplingfrequencies. Sampling may be undertaken more

frequently according to the risk assessment. It isimportant that samples are taken as described inAppendix 3 to avoid false negatives.


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Figure 2 Summary o suggested water sampling and testing requencies

Not detected 110 cfu/100 mL >10 cfu/100 mL

Water sample (pre-flush)

Risk-assess removingoutlet from service andretest (pre-/post-flush)

Retest after an additional4 weeks

Reinstate outlet and retest

after an additional 2 weeks

Retest at 3 days

Remediation(see paragraph 4.49)

Retest (pre-/post-flush) +ve

ve

ve

ve

ve

+ve

+ve

+ve

Sample every 6 months

Satisfactory:no further action

required

Interpretation of pre- and post-flush counts A few positive outlets, where the majority of4.46 High counts in pre-flush samples but with low outlets are negative, would also indicate that counts or none detected at post-flush could indicate the source of contamination is at or close to the that areas/fittings at or near the outlets are the source outlet.of contamination (see Table 1).

If both pre- and post-flush samples from aparticular outlet are >100 cfu/100 mL and other

Table 1 Interpretation o pre- and post-lush counts

High P. aeruginosacount pre-lush (>10 cu/100 mL)and low post-lush count (10 cu/100 mL)and high post-lush count (>10 cu/100 mL)

Suggestive o a problem not related to a local wateroutlet but to a wider problem within the water supplysystem

13


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Figure 3 Summary o sampling procedure and interpretation o results orP. aeruginosa

No further actionrequired.

Samples taken in accordance with agreed written

protocols, on behalf of the Estates & Facilitiesdepartment, and correctly stored (if appropriate)and transported to a laboratory that is capable ofprocessing and testing.

Results requiring action are identified.Nominated people informed.Appropriate course of action per outlet isimplemented.

Results returned to nominated Estates &Facilities and IPC teams that are members of theWater Safety Group.

Not detected 110 cfu/100 mL >10 cfu/100 mL

See paragraph4.43

nearby outlets have no or low counts, this showsthat the single outlet is heavily contaminated,despite the high post-flush count. This could be

explored by testing dilutions of pre- and post-flush water samples from this outlet or by usingan extended flush such as for 5 minutes priorto post-flush sampling.

See paragraphs4.44 and 4.45

then be sampled to assess the extent of the problem(see Table 1).

4.48 Figure 3 provides a summary of the samplingprocedure and interpretation of results forP. aeruginosa.

What to do i a contamination problemis identiied4.49 Should risk assessment or water testing identifycontamination with P. aeruginosa, the followingriskreduction and preventive measures should beconsidered.

a. If a water outlet has been taken out of servicebecause of contamination with P. aeruginosa,continue daily flushing while the outlet is out

Note:

Overlaying sample results onto schematicdrawings of the system may help to identify thesource of contamination and locations foradditional sampling.

4.47 If the sampling indicates that the water servicesare the problem, then most outlets would possibly bepositive and other points in the water system could

14


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15


of normal use to prevent water stagnation andexacerbation of the contamination.

b. Where practical, consider removal of flow

straighteners. However, the removal of flowstraighteners may result in splashing andtherefore additional remedial action may needto be taken. If they are seen to be needed,periodically remove them and either clean/disinfect or replace them. Replacementfrequency should be verified by sampling/swabbing.

c. Splashing can promote dissemination oforganisms, resulting in basin outlets becoming

heavily contaminated. If splashing is found tobe a problem, investigate the causes. Examplecauses include:

(i) the taps designed flow profile isincompatible with the basin;

(ii) the tap discharges directly into the wasteaperture;

(iii) incorrect height between tap outlet andsurface of the basin;

(iv) excess water pressure;

(v) a blocked or malfunctioning flowstraightener.

d. Hand-washing should be supplemented withthe use of antimicrobial hand-rub.

e. To prevent water stagnation, check forunderused outlets assess frequency of usageand if necessary remove underused outlet(s).

For example, the provision of showers in areaswhere patients are predominantly confined tobed, and the resultant lack of use, could lead tostagnation.

f. Check connections to mixing taps to ensurethat the supply to the hot connection is notsupplied from an upstream TMV. In a hot-

water service, a dead-leg will exist between thecirculating pipework and hot connection of afitting such as a mixing tap. In the case of cold-

water services, sometimes there will be nodraw-off from any part of the system and theentire service is in effect a dead-leg. Tominimise the stagnation of water in a cold-

water system, it can be beneficial to arrange thepipework run so that it ends at a frequentlyused outlet. A dead-leg may also exist when aTMV is installed upstream of a mixing tap (seeFigure 4). Depending on the activities of the

room in which the tap is located, cold watermay never be drawn through the pipe betweenthe cold water connections of the mixing valveand mixing tap.

g. Assess the water system for blind ends anddead-legs (for example, where water is suppliedto both the cold-water outlet and a TMVsupplying an adjacent blended water outlet, assuch cold-water outlets in augmented care unitsmay be commonly underused). When

removing outlets, the branch hot- and cold-water pipes should also be cut back to the maindistribution pipework in order to eliminateblind ends.

Hot water

return

Cold water

supply

Hot water

flow

Hot water

return

Hot water

flow

In the case of (a), as the tap lever is moved progressively fromleft to right, only cold water will be drawn through initially.When fully to the right, cold water will cease to flow and water

will flow from the upstream TMV.

In the case of (b), if the lever remains in the fully hot position, asit is raised to draw-off water, there may never be flow from thedirect cold-water pipe supplying the tap.

(a) (b)

TMV

Mixed safe hotwater supply

to tap

TMV

Cold watersupply to tap

Manual mixingtap

Cold watersupply

Cold watersupply to tap

Figure 4 Dead-leg ormed by the cold pipework when aTMV is installed upstream o a mixing tap


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h. Assess the water distribution system for nonmetallic materials that may be used in itemssuch as inline valves, test points and flexiblehoses. They should be replaced according tothe guidance in safety alert (DH (2010) 03:Flexible water supply hoses.

i. All materials must be WRAS-approved andmust not leach chemicals that provide nutrientsthat support microbiological growth. Materialsshould also be compatible with the physicaland chemical characteristics of water suppliedto the building. Flexible pipes should only beused in exceptional circumstances (for example,

where height adjustment is necessary as ininstallations such as rise-and-fall baths andhand-held showers).

j. POU filters, where they can be fitted, may beused to provide water free ofP. aeruginosa.

Where fitted, regard filters primarily as atemporary measure until a permanent safeengineering solution is developed, althoughlong-term use of such filters may be required insome cases. Where POU filters are fitted totaps, follow the manufacturersrecommendations for renewal and replacementand note that the outer casing of a POU filter

and the inner surface can become contaminated (see Health Technical Memorandum 04-01 Part B).

k. In certain circumstances, the WSG may decideit is necessary to carry out a disinfection of thehot- and cold-water distribution systems thatsupply the unit to ensure that contaminatedoutlets are treated. See Health TechnicalMemorandum 04-01 (Part A Chapter 17) forguidance on how to carry out the disinfectionprocedure. Note that with respect toP. aeruginosa, hyperchlorination is not effectiveagainst established biofilms. Consider replacingcontaminated taps with new taps; however,there is currently a lack of scientific evidence tosuggest that this will provide a long-termsolution. When replacing taps, consider fitting:

(i) removable taps;

(ii) taps that are easy to use;

(iii) taps that can be readily dismantled for cleaning and disinfection;

(iv) taps to which a filter can be attached to the

spout outlet. Note: Such taps can be usedfor supplying water for cleaning incubatorsand other clinical equipment.

Note:

In the event of an outbreak or incident, further advice on the management ofP. aeruginosacontamination in water systems can be sought from PHE.
http://www.dh.gov.uk/en/Publicationsandstatistics/Lettersandcirculars/Estatesalerts/DH_115807http://www.dh.gov.uk/en/Publicationsandstatistics/Lettersandcirculars/Estatesalerts/DH_115807


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Appendix 1 Best practice advice relating to clinical wash-hand basins

Appendix 1 Best practice advice

relating to all clinical wash-handbasins in healthcare acilities

Notes:

1. Clinical wash-hand basins are particularly highrisk. It is therefore important to ensure thecleaning of these basins and the taps isundertaken in a way that does not allow cross-contamination from a bacterial source to the tap.During cleaning of basins and taps, there is a riskof contaminating tap outlets withmicroorganisms if the same cloth is used to cleanthe bowl of the basin or surrounding area beforethe tap. Waste-water drain outlets are particularlyrisky parts of the basin/system and are almostalways contaminated (see Breathnach et al. 2012).Bacteria may be of patient origin, so it is possible

that bacteria, including antibiotic-resistantorganisms, could seed the outlet, become residentin any biofilm and have the potential to betransmitted to other patients.

2. If POU filters are fitted to taps, the samecleaning regimen applies to the wash-hand basin,but clean the filter itself according to themanufacturers instructions. Take care to avoidcontaminating the external surface and outlet ofthe filter.

Use the clinical wash-hand basin only for hand-washing:

a. Do not dispose of body fluids at the clinicalwash-hand basin use the slophopper or sluicein the dirty utility area.

b. Do not wash any patient equipment in clinicalwash-hand basins.

c. Do not use clinical wash-hand basins for

storing used equipment awaiting decontamination.

d. Do not touch the spout outlet when washinghands.

e. Clean taps before the rest of the clinical wash-hand basin. Do not transfer contamination

from wash-hand basin to wash-hand basin.

f. Do not dispose of used environmental cleaningagents at clinical wash-hand basins.

g. Make sure that reusable containers containingenvironmental cleaning agents are used in amanner that will protect them fromcontamination with P. aeruginosa(see Aumeranet al. 2007; Ehrenkranz et al, 1980; Sautter etal., 1984).

h. Use non-fillable single-use bottles for antimicrobial hand-rub and soap.

i. Consider the appropriate positioning of soapand antimicrobial hand-rub dispensers. Thecompounds in the products can be a source ofnutrients to some microorganisms. Therefore,it is advisable to prevent soiling of the tap bydrips from the dispensers or during themovement of hands from the dispensers to thebasin when beginning hand-washing.

j. Identify and report any problems or concernsrelating to safety, maintenance and cleanlinessof wash-hand basins to the WSG. Escalateunresolved issues to higher management and/orthe IPC team as appropriate.

Management should ensure that all staff withresponsibility for cleaning should be adequatelytrained and made aware of the importance of highstandards of cleanliness. Refresher training should be

given where a specific area does not maintain theexpected standard of cleanliness. Visual monitoringof domestic staff should be undertaken by means ofregular audits.

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18


Appendix 2 Types and method o

operation o taps and TMVs

Manual mixing taps (non-TMV):1. There are three main types of manual mixing tap:

Single sequential lever operation. This is thesimplest type. As the lever is moved from left toright, or vice-versa, cold water begins to flow

and progressively hot water is introduced intothe tap body until a fully hot flow is achieved.

Single lever combined temperature and flowcontrol. This type has a lever that may bemoved from left to right to control temperatureand raised and lowered to control and turn onand off the water flow.

Dual lever. This type has separate levercontrols for both the hot and cold water supplyto the mixed temperature outlet. As these taps

are not normally accessible to patients, theprovision of a thermostatic control may be seenas unnecessary.

Note:

The decision whether to install a TMV in areasnot normally accessible to patients should bebased on a risk assessment (see paragraphs 4.114.26). If the risk assessment determines that thereis a potential scalding risk, the manual mixingtap should be:

a. preceded by a TMV to ensure that the hotwater at the point of discharge is suppliedat a safe temperature;

b. a Type 1 tap, which incorporates amaximum temperature stop to ensure bothhot and cold supplies are always flushed.

See Note after paragraph 3.7.

Sensor-operated tap2. This is essentially an outlet spout of a tap with nomanual lever or controls. On/off control of water isby means of a solenoid valve that is activated by aninfrared or similar sensor to detect the presence of

the user. (Some taps require the metal surface of thespout to be touched.) Water temperature iscontrolled by a TMV fitted upstream or downstreamof the solenoid valve.

Thermostatic mixing tap3. These are often referred to as mixing taps withintegral TMVs. They contain an automatictemperature-controlling device such as a TMV buthave an operating mechanism to adjust temperaturefrom fully cold to the maximum pre-set blended

water temperature permitted by the automaticdevice. In the event of failure of the cold watersupply, the mixed/blended temperature outlet port

will be automatically closed to prevent high watertemperature being discharged. The operating

mechanism can also control and turn on/off thewater flow. They can also be separate mechanisms,functioning independently, with one actuating theflow of mixed water at a fixed temperature and theother actuating the flow of cold water.

Thermostatic mixing valve (TMV)4. TMVs are typically configured as a t-shaped device

with opposing hot and cold water inlets and a mixed/blended temperature water outlet (see paragraph4.49(f)). They are pre-set to deliver a fixed

temperature and, in the event of failure of the cold-water supply pressure, will automatically close toprevent discharge of excessively hot water at the outlet.

Guidance on the selection of taps and basins used in healthcare is given in Health Building Note 00-10 Part C Sanitary assemblies.

For more information on the TMV approvalscheme, visit BuildCert at http://www.buildcert.com/tmv3.htm).

Information on the construction and operationof taps/TMVs used in healthcare can be foundon the TMVA website (http://www.tmva.org.uk).
http://www.buildcert.com/tmv3.htmhttp://www.buildcert.com/tmv3.htmhttp://www.tmva.org.uk/http://www.tmva.org.uk/http://www.buildcert.com/tmv3.htmhttp://www.buildcert.com/tmv3.htm


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Appendix 3 Water sampling

Appendix 3 Water sampling

1. Sampling should be undertaken by staff trained inthe appropriate technique for taking water samplesincluding the use of aseptic technique to minimiseextraneous contamination. The method used in thisguidance may differ from the collection of watersamples for other purposes (for example, forsamplingLegionella).

2. Carefully label samples such that the outlet can beclearly identified; system schematics indicating each

numbered outlet to be sampled can be helpful in thisrespect.

3. The main strategy for sampling is to take the firstsample of water (pre-flush) delivered from a tap at atime of no use (at least 2 hours or preferably longer)or, if that is not possible, during a time of its lowestusage. This will normally mean sampling in the earlymorning, although a variety of use patterns mayneed to be taken into account.

4. Disinfectants in the water, such as chlorine or

chlorine dioxide, will have residual activity aftertaking the sample and may inactivate bacteria in thesample prior to its processing. To preserve themicrobial content of the sample, neutralise oxidisingbiocides by dosing the sample bottle with 18 mg ofsodium thiosulphate (equating to 18 mg/L in thefinal sample, which will neutralise up to 50 ppmhypochlorite). Sterile bottles are normally purchasedcontaining the neutraliser. EDTA(ethylenediaminetetraacetic acid) may be used as aneutraliser for systems treated with copper and silver

ions (BS 7592). The relevant Health & SafetyExecutives advice regarding the use of elementalcopper as biocide should be consulted (http://www.hse.gov.uk/legionnaires/faqs.htm#silver-coppersystems). Where disinfectants are being applied tothe water system, take advice on the appropriateneutralisers to use.

5. The tap should not be disinfected by heat orchemicals before sampling (pre- or post-flush seeparagraph 12), nor should it be cleaned or disinfectedimmediately before sampling.

6. Label a sterile collection vessel (2001000 mLvolume) containing a suitable neutraliser for anybiocide the water may contain. The labellinginformation should contain details of the tap location,

senders reference, pre- or post-flush (see paragraph12), person sampling, date and time of sampling.

7. IfP. aeruginosahas been found in a pre-flushsample, take a second paired set of samples. The first

would be a pre-flush sample as before. Run the tapfor two minutes and take a second identical post-flush sample. Bacteria in this second sample (termedpost-flush) are more likely to originate further backin the water system. A substantially higher bacterial

count in the pre-flush sample, compared with thepost-flush, should direct remedial measures towardsthe tap and associated pipework and fittings near tothat outlet. A similar bacterial count in pre-flush andpost-flush samples indicates that attention shouldfocus on the whole water supply, storage anddistribution system. A more extensive samplingregimen should be considered throughout the waterdistribution system, particularly if that result isobtained from a number of outlets.

8. Although water sampling is the principal means ofsampling, there may be occasions when watersamples cannot be obtained immediately for analysis.In the event of a suspected outbreak, swabbing wateroutlets (as per section 5.4 of the StandingCommittee of Analysts (SCA) 2010 guidance) toobtain strains for typing may provide a means ofassessing a water outlet, but this does not replace

water sampling (see paragraph 15 on swabbing).

Procedure or obtaining the samples9. Pre-flush sample: Aseptically (that is, withouttouching the screw thread, inside of the cap or insideof the collection vessel) collect at least 200 mL waterin a sterile collection vessel containing neutraliser.Replace the cap and invert or shake to mix theneutraliser with the collected water.

10. Dependent upon the water distribution systemdesign, and the type of water outlet, the water feedto the outlet may be provided by:

a separate cold-water supply and hot-watersupply to separate outlets;

a separate cold-water supply and hot-watersupply, which may have its final temperaturecontrolled by the use of an integral TMV

within the outlet; or

19
http://www.hse.gov.uk/legionnaires/faqs.htm#silver-copper-systemshttp://www.hse.gov.uk/legionnaires/faqs.htm#silver-copper-systemshttp://www.hse.gov.uk/legionnaires/faqs.htm#silver-copper-systemshttp://www.environment-agency.gov.uk/static/documents/Research/MoDW-2-232.pdfhttp://www.environment-agency.gov.uk/static/documents/Research/MoDW-2-232.pdfhttp://www.environment-agency.gov.uk/static/documents/Research/MoDW-2-232.pdfhttp://www.environment-agency.gov.uk/static/documents/Research/MoDW-2-232.pdfhttp://www.hse.gov.uk/legionnaires/faqs.htm#silver-copper-systemshttp://www.hse.gov.uk/legionnaires/faqs.htm#silver-copper-systemshttp://www.hse.gov.uk/legionnaires/faqs.htm#silver-copper-systems


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Collect at least 200 mL water in a sterile collection vessel

a separate cold-water and a pre-blended hot-water supply that has had its temperaturereduced by a TMV prior to delivery to theoutlet.

11. For separate hot- and cold-water outlets, eachoutlet is individually tested with its own collectionvessel and outlet identifier. For blended outlets (thatis, where both hot and cold water come out of the

same outlet): sample water with the mixing tap set to the

fully cold position using an individualcollection vessel and outlet identifier, and notethe temperature setting;

sample the blended outlet set to the maximumavailable hot-water temperature using anindividual collection vessel and outlet identifier,and note the temperature setting.

12. Post-flush sample: where this is required, allow

the water to flow from the tap for 2 minutes (see

above) before collecting at least 200 mL water in asterile collection vessel with neutraliser. Replace thecap and invert or shake to mix the neutraliser withthe collected water. This sample, when takentogether with the pre-flush sample, will indicate

whether the tap outlet and its associated componentsis contaminated or if the contamination is remotefrom the point of delivery (see Table 1).

13. If a sample from a shower is required, then placea sterile bag over the outlet. Using sterile scissors, cuta small section off the corner and collect the samplein a sampling container (see PHEs (2013)Guidelines for the collection, microbiologicalexamination and interpretation of results from food,

water and environmental samples taken from the

healthcare environment (forthcoming)).Appropriate precautions should be taken tominimise aerosol production as described in BS7592.

14. The collected water should be processed within 2hours. If that is not possible, then it should berefrigerated within 2 hours and kept at 28C andprocessed within 24 hours.

15. To take a swab sample, remove a sterile swabfrom its container and insert the tip into the nozzle

of the tap. Care should be taken to ensure no othersurfaces come into contact with the tip of the swab.Rub the swab around that is, move it backwardsand forwards and up and down, as much as possible,on the inside surface of the tap outlet or flowstraightener (see photograph). Replace the swabcarefully in its container, again ensuring no othersurfaces come into contact with the tip of the swab.Place the swab in a transport medium or maximumrecovery diluent (MRD) and send to the laboratory.

A sterile swab should be rubbed on the inside surface of the tap outlet

or flow straightener


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Appendix 4 Microbiological examination o water samples or P. aeruginosa

Appendix 4 Microbiological

examination o water samples orP. aeruginosa

Notes:

This appendix has been developed to providetechnical guidance for a range of laboratories(including NHS, PHE and commercial

laboratories) that have the capability and capacityto undertake water sampling and testing.

Alternative water-testing methods other thanfiltration that can show equivalence and/orimprovement on the sensitivity and enumerationofP. aeruginosaare also acceptable.

An oxidase test alone is not sufficiently specific toidentifyP. aeruginosa.

Deinition1. P. aeruginosaare Gram-negative, oxidase-positivebacteria that, in the context of this method, grow onselective media containing cetrimide (cetyltrimethylammonium bromide), usually producepyocyanin, fluoresce under ultraviolet light 360 20nm, and hydrolyse casein. P. aeruginosaneeds to beidentified by the following methods identificationby a positive oxidase test alone is insufficient.

Testing principle2. A measured volume of the sample or a dilution ofthe sample is filtered through a membrane filter(0.45 microns) to retain bacteria and the filter isthen placed on a solid selective and differentialmedium.

3. CN agar contains cetyl trimethylammoniumbromide and nalidixic acidat concentrations that

will inhibit the growth of bacteria other thanP. aeruginosa. Other selective and differential agars

are available and acceptable if validated.

4. The membrane is incubated on a selective/differential agar and characteristic colonies arecounted. Confirmatory tests are carried out where

necessary (see paragraph 15) and the result iscalculated as the colony count per 100 mL of water.

5. P. aeruginosausually produces characteristic blue-green or brown colonies when incubated at 37C for

up to 48 hours. Confirmation of isolates is by subculture to milk agar supplemented with cetyltrimethylammonium bromide (commerciallyavailable) to demonstrate hydrolysis of casein.

Sample preparation and dilutions6. Water samples should be received and handled asdescribed in the SCAs 2002 guidance (currentlyunder review). For example, samples should beexamined as soon as is practicable on the day ofcollection. In exceptional circumstances, if there is a

delay, store at 28C and do not exceed 24 hoursbefore the commencement of analysis.

Filtration and incubation7. Aseptically measure and dispense 100 mL of watersample into the sterile filter-holder funnel. If thefunnel is graduated to indicate volume, this can alsoserve to measure the volume.

8. If high bacterial numbers are present in watersamples, it may be impossible to count individualcolonies accurately on the filter membrane.Therefore, if high counts are expected, a range ofdilutions made in sterile diluent (water, MRD orsimilar) can be processed in parallel with theundiluted sample. An example of this would be a1-in-10 and a 1-in-100 dilution processed as well asan undiluted sample. Filtration of 10 mL rather than100 mL is an alternative to filtering 100 mL of a 1-in10 solution.

9. Draw the water sample through the filter.

10. Aseptically place the membrane onto thepseudomonas selective and differential agar (seeparagraph 3) and incubate aerobically at 37C.

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Counting o colonies11. Examine plates after 22 hours 4 hours and 44hours 4 hours of incubation.

12. Count all colonies that produce a green/blue(demonstrating pyocyanin production), or reddish-brown pigment and those which fluoresce underultraviolet light (optional). Exposure of colonies todaylight for 24 hours enhances pigmentproduction. When there is a moderately heavygrowth ofP. aeruginosaand other organisms on themembrane, colonies adjacent to pyocyaninproducing colonies ofP. aeruginosacan also appeargreen after 44 hours 4 hours of incubation, makingthe interpretation of the count difficult. Observingthe plates after 22 hours 4 hours assists in theinterpretation in these instances.

Plate showing high counts of pyocyanin-producing colonies of

P. aeruginosa

Processing o swabs13. Swabs can show presence ofP. aeruginosabut willnot provide equivalent quantitative results as watersampling. They can be used to show the presence or

absence ofP. aeruginosaat the outlet.

14. In the laboratory, use the swab to inoculate aportion of an agar plate that is selective anddifferential for P. aeruginosa(see paragraphs 2 and 3).Streak the inoculum on the plate as for a clinicalsample. Incubate as described for filter samplesabove. Alternatively, after sampling, place the swabin 10 mL MRD, vortex, then plate out (using serialdilution) on the appropriate media and incubate asabove.

Conirmatory tests15. Colonies that clearly produce pyocyanin (green/blue pigmented) on the membrane are considered to

be P. aeruginosaand require no further testing. Othercolonies which fluoresce or are red/brown requireconfirmation. If more than one volume or dilutionhas been filtered, proceed if possible with themembrane yielding 2080 colonies to enableoptimum identification and accurate enumeration ofcolonies. Where there is doubt, perform additionaltests to yield reliable species identification.

16. To confirm other colonies, subculture from themembrane onto a milk cetrimide agar (MCA) plateand incubate at 37C for 22 hours 4 hours.Examine the plates for growth, pigment, fluorescenceand casein hydrolysis (clearing mediums opacityaround the colonies). If pigment production is poor,expose the MCA to daylight at room temperature for24 hours to enhance pigment production and reexamine.

17. P. aeruginosais oxidase-positive, hydrolyses caseinand produces pyocyanin and/or fluorescence.Occasionally atypical non-pigmented variants ofP. aeruginosaoccur. A pyocyanin-negative, casein

hydrolysis-positive, fluorescence-positive cultureshould be regarded as P. aeruginosa. Additional testsmay be necessary to differentiate non-pigmentedP. aeruginosafrom P. fluorescens(such as growth at42C or resistance to C-390, 9-chloro-9-(4diethylaminophenyl)-10-phenylacridan orphenanthroline or more extensive biochemical tests).

Table A1Colony on

CN agar

Oxidase

test

Fluorescing

on MCA

Caseinolytic

on MCA

Conirmed

P.aeruginosa

Blue orgreen

+ NT NT Yes

Fluorescingand notpigmented

+ + + Yes

Reddishbrownnon-luorescing

+ +/ + Yes

NT = No testing necessary

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Appendix 4 Microbiological examination o water samples or P. aeruginosa

Retention o P. aeruginosaisolates18. Where an investigation into clinical infections isunderway, inform the testing laboratory that the

isolates ofP. aeruginosaand associated samplinglocation information should be retained for aminimum of three months as they may be requiredfor typing at a later date.

19. It will then be the responsibility of the testinglaboratory to ensure that these isolates are suppliedto the typing laboratory (for example, PHE atColindale) when requested, and this should be

written into the contract for testing.

Calculation o results20. Express the results as colonies ofP. aeruginosaper100 mL of the undiluted sample, for example:

for 100 mL sample the count on the membrane;

for 10 mL of sample the count on the membrane multiplied by 10;

for 1 mL of sample the count on the membrane multiplied by 100.

Reporting21. IfP. aeruginosais not detected, report as Notdetected in 100 mL.

22. If the test organism is present, report as thenumber ofP. aeruginosaper 100 mL. Reports shouldbe specific to P. aeruginosa, and not genericPseudomonasspecies.

23. The sample reference originally submitted should

be reported with each result.

Microbiological typing24. Water and/or tap-swab isolates being sent toPHEs Antimicrobial Resistance and Healthcare

Associated Infections (AMRHAI) Reference Unit formolecular analysis ofP. aeruginosashould only be

referred if the isolates have been confirmed to beP. aeruginosaand if there is a possible link to theoutbreak strain under investigation.

25. Referrals ofP. aeruginosaisolates for typingshould only be sent after consultation with thetyping laboratory.

26. Where many taps are positive for P. aeruginosa,send one colony of the P. aeruginosafrom each watersample. Save the primary isolation plate for possiblefurther examination once the results of typing areknown and have been discussed with the typinglaboratory. Analysis of results to date has consistentlyshown that multiple picks have been representatives

of the same strain; since multiple taps are beingsampled, an idea of the extent of homogeneity orotherwise will still be gained where only one colonyis sent from each water sample.

27. If only two or three taps are positive forP. aeruginosa, then send two separate colony picks ofconfirmed P. aeruginosafrom the primary plate per

water sample to AMRHAI (taking the stipulations inparagraph 25 into account). Label these clearly asbeing from the same water sample (so that AMRHAIcan accumulate data on how common mixed strainsare seen in the same tap water).

28. It is important that the request forms haveinformation about the links between tap water andcases as illustrated in the following examples:

a. water from tap in room A ref patient X;

b. water from tap in sluice room;

c. tap water from room C with no cases.

29. It is important to recognise that there are sometypes ofP. aeruginosathat are relatively commonlyfound in the environment and among patientsamples globally. These include the PA14 clone andclone C; a match between patient and water samples

with these strains is not necessarily evidence oftransmission between the two.

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24


Filter

Aseptically place the membrane onto the pseudomonas selective and differential agar and incubate at

37C; examine after 22 hours 4 hours and 44 hours 4 hours

Count all colonies that produce a green/blue or reddish-brown pigment and those that fluoresce underUV light (optional)

Subculture non-pyocyanin-producing (green/blue) colonies to MCA and incubate at 37C for 22 4 hours

Calculate confirmed count and report as P. aeruginosa

Process within 2 hours. If not possible, refrigerate within 2 hours, keep at 28C and processwithin 24 hours

Maintain the cold chain during transport of the sample to the laboratory

Make any necessary dilutions

Flowchart showing the processing and enumeration ofP. aeruginosa by membrane filtration

Examine the plates for growth, pigment, fluorescence and casein hydrolysis. If pigment production is poor,expose the MCA to daylight at room temperature for 24 hours to enhance pigment production and

re-examine


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Appendix 5 Example o a typical risk assinorm the WSP or augmented care units

Infection/colonisation withPseudomonas aeruginosafrom contaminated water

Susceptible patients withinaugmented care units

USE OF WATER:For direct contact with patients, water ofa known satisfactory quality is used: water where testing has shown absenceof P. aeruginosa; or

water supplied through a point-of-use(POU) filter; or

sterile water (for skin contact for babiesin neonatal intensive care units).

ENGINEERING ASSESSMENT OF WATERSYSTEMS: Correct installation and commissioningof water systems in in line with HTM04-01 is adhered to

Schematic drawings are available forwater systems.

FLUSHING: Flushing of water outlets is carried outand documented.

SAMPLING: Plans for the sampling and microbio-logical testing of water are in place

Description of the hazardsPersons affected by thework activity and how

Existing controls Likeliho

Facility/ward/department: Assessment completed by:

Date:

(Names/titles):

Brief description of activity, location or equipment: to determine the level of risk that Pseudomonas aeruginosa from the watepatients in the unit

Note to reader: This is anexample risk assessment. The

control measures outlined arenot exhaustive but are forillustrative purposes only.Each healthcare provider willhave its own risks and willneed to carry out a riskassessment based on theserisks (see paragraphs 4.18-4.23 for examples of otherrisks and further guidance).2

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Risk scoring matrix

Risk scoring: Use the grid below to achieve and overall score for the risk by measuring across for the impact alikelihood.

IMPACT

1 2 3 4

LIKELIHO

OD

1 1 2 3 4

2 2 4 6 8

3 3 6 9 12

4 4 8 12 16

5 5 10 15 20

KeyGreenLow

AmberMedium

The resulting action plan should include:

Sources of information/persons consulted Further action if necessary to control the risk Person/s responsible for coordinating implementation of the acti Recommended timescales Date completed Revised risk rating


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Appendix 6 Exemplar P. aeruginosa sample sheet

Appendix 6 ExemplarP. aeruginosa

sample sheet

Hospital/site: St Lukes

Building: East Wing

Faculty/department/ward: 12

Time sample taken: 07.00

Date: 20 February 2013

Name of sampler (print): J. JONESBacterial species:Pseudomonas aeruginosa

Note: The tap should not be cleaned or disinfected by heat or chemicals immediately before sampling

RoomNo.

Roomname

Outlettype

OutletID No.

Pre-flushsample

Post-flushsample

Samples barcode (affixadjacent to sample details)

HTM0401 Addendum P.aeuginosa

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