Pseudomonas aeruginosa and hospital water systems-1 21

Report
Pseudomonas aeruginosa and
hospital water systems
Dr Chinari P K Subudhi
Consultant Microbiologist & Clinical Lead
Salford Royal Hospital
Outbreaks of P. aeruginosa

Intensive care units

Neonatal intensive care units

Burns units

Haematology units
Premature babies in NICU

Very susceptible to infection with P.aeruginosa

Immature immune system

Immature and delicate skin – can be damaged and
infected easily

Presence of devices i.e ventilation, catheters, etc
increase the risk of colonisation and infection

Incubator – humid environment – favourable for P.
aeruginosa to thrive
Water - reservoir or vehicle

Moist environment and aqueous solutions in
health care settings have potential to serve as
reservoirs for water borne organisms

Favourable circumstances eg., temperature,
presence of source of nutrition, etc – can
facilitate active growth of organisms or they
remain for long periods in highly stable and
resistant forms
Water – point source outbreaks

Contaminated water baths

Humidifying equipment for ventilators

Taps and sink drains

Feeding bottles

Mineral water bottle
Water borne infections – Modes of transmission

Direct contact (eg. hydrotherapy pool)

Ingestion of water (eg. consuming contaminated ice)

Indirect contact transmission (eg. contaminated hands,
devices, equipment, surfaces etc)

Inhalation of aerosols dispersed from water sources i.e.
from fountains, showers, cooling towers, air-conditioning
units

Aspiration of contaminated water
Water borne bacterial agents causing infections or
outbreaks in health care facilities

Legionella sp.

Pseudomonas aeruginosa

Other Gram negative bacteria – Pseudomonas sp,
Burkholderia cepacia, Ralstonia picketii, Stenotrophomonas
maltophila, Sphingomonas sp, Acinetobacter sp, Enterobacter
sp, Serratia sp.

Nontuberculous mycobacteria
Pseudomonas aeruginosa

Commonly found in soil, water and plants

Can colonise healthy humans and animals

Tolerant to temperature as high as 45°C to 50°C

Can produce a biofilm which creates a protective
layer when it grows in the water system

Opportunistic pathogen – more likely to infect those
who are already very sick or vulnerable

Relatively resistant to many antibiotics
Pseudomonas aeruginosa (culture)
Habitat of P.aeruginosa in hospitals

Can colonise moist surfaces of patients on
axilla, ear, perineum, wounds, etc

Can be isolated from other moist, inanimate
environments including water in sinks and
drains, toilets and showers

Hospital equipment that comes in contact with
water such as mops, respiratory ventilators,
cleaning solutions and food and food processing
machines, can be source
Pseudomonas and water systems
Water systems frequently colonised with
Pseudomonas with biofilms developing in pipework,
taps and U bends when there is a source of carbon
for growth
Insufficient temperature favours growth – below
55°C in hot water pipes and above 20°C in cold
water pipes
 Stagnant water in system if taps are not used or
flushed regularly
 Secondary contamination of taps and sinks because
of inappropriate infection control practices

Human carriage of P. aeruginosa

Up to 7% of healthy humans carry in throat,
nasal mucosa or on the skin

Faecal carriage rates – 15% to 25% reported,
higher in vegetarians

Dies rapidly on dry human skin

Survives well in moist or superhydrated skin
Examples of community acquired
infections due to P. aeruginosa

Skin infections – Folliculitis - related to use of hot tubs,
whirlpools, swimming pools, other baths; Toe web rot in
soldiers – interdigital space between the toes

Eye infection in contact lens wearers (extended wear
variety) – Ulcerative keratitis – because of contamination of
the contact lens solutions

Ear infections – Otitis externa (Swimmer’s ear)

Respiratory tract infections – Cystic fibrosis, Bronchiectasis
Hot tub folliculitis
Health care associated infections (HCAI) – P.
aeruginosa

Ventilator associated pneumonia

Hospital acquired pneumonia

Urinary tract infections – catheter associated

Wound infections – eg. burns, ulcers, exit sites

Bacteremia
Patient on mechanical ventilation
Department of Health, March 2012

Water sources and potential Pseudomonas aeruginosa
contamination of taps and water systems
Advice for augmented care units
Previous guidance issued by CMO in August 2010 & February 2012 as
“Dear Colleague” letters
Best practice technical guidance to reduce risk to patients and
recommendations to establish systems to monitor, prevent and control
infections
Intended for professionals engaged in infection prevention and control,
estates and facilities and the Responsible person (Water)
Advice to health care providers

Assessing risk to patients if water systems become
contaminated with P.aeruginosa or other pathogens

What actions to take if water systems become
contaminated with P.aeruginosa

Protocol for sampling, testing and monitoring water for
P.aeruginosa

Developing local water safety plans
Risk assessment

Should be undertaken to identify actions to
mitigate risks by June 2012

To ensure appropriate sampling, monitoring and
clinical surveillance arrangements are being
implemented and adhered to

To undertake appropriate water sampling by end
of 2012 where required
Water Safety Group

A multi-disciplinary group to undertake risk assessment and management
of water safety issues

Identification of microbiological hazards, assessing risks, identifies and
monitors control measures and develop incident protocols

Can be a sub-group of the hospital’s Infection control committee

Accountable to DIPC

Comprising:
◦
◦
◦
◦
◦
◦
Infection prevention and control team
Consultant Medical Microbiologist
Estates and Facilities
Senior nurses from relevant augmented care units
Hotel / cleaning services
Director of infection prevention and control (DIPC)
Risk assessment in hospitals

Local risk assessment required for identification
of vulnerable patient groups

Case mix and patient susceptibility varies
between units

Risk assessment of environment and practices

For incorporating appropriate preventative
measures and monitoring arrangements
Augmented care units
Critical Care areas – Adult ICU, Pediatric
ICU, Neonatal ICU
 High Dependency units
 Burns units
 Transplant Units
 Haematology – Oncology wards
 Renal units / wards

Hospital water systems and patient safety

Correct maintenance of hot and cold water
supply systems

Continuous delivery of microbiologically
safe water

Effective management and operation
throughout the water supply and
distribution system
Role of Infection prevention and
control teams

Ensure application of and compliance with appropriate
guidelines to prevent HCAI

Ensure best practice advice relating to hand wash stations
is followed to minimise risk of P.aeruginosa contamination

Continue to monitor clinical isolates of P.aeruginosa as an
alert organism

To be aware of possible outbreaks of infection with
P.aeruginosa
Hand wash stations – Best practice

ONLY FOR HANDWASHING
No disposal of body fluids
 No disposal of used environmental cleaning fluids
 No washing of patient equipment
 No storing of used equipment awaiting decontamination
 Taps should be cleaned before the rest of the handbasin
(NHS Cleaning manual)
 Washing patients with water from outlets
demonstrated to be safe

Flushing taps

HTM 04-01 Part B, Chapter 5

All taps that are infrequently used – to be
flushed regularly manually – at least daily in the
morning for 1 minute

Some taps can be programmed to flush
automatically, such flushing could be recorded
on the building management system

Keep a record of when the taps were flushed
Wash hand stations – problems / concerns

Identify any problems or concern relating
to safety, maintenance and cleaning of
wash hand stations to
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Infection Prevention & Control Team
Estates
Facilities Department
Infection control committee – if there are
unresolved issues
Risk assessment - factors to consider

Susceptibility of patient groups

Clinical practice and ongoing care of invasive devices

Cleaning of patient equipment

Engineering assessment of water systems – installation,
commissioning and maintenance

Sampling and monitoring programme
Water safety plan (WSP) – Legionella and
P.aeruginosa

To assist with understanding and mitigating risks
associated with bacterial contamination of
water distribution and supply system

To provide a risk-management approach to the
microbiological safety of water

To establish good practices in local water
distribution and supply
WSPs

Working documents should be kept up to date and to be
reviewed annually

Responsible person (Water) should lead the development
of WSP and will be responsible for it’s implementation

Complement the existing Operational management
requirements of HTM 04-0

Complement the work that has to be undertaken to fulfill
the statutory requirement for a Legionella risk assessment
and written scheme for the control and management of
Legionella
Protecting the patients when water contamination
problem is suspected / confirmed
Use water of a known satisfactory quality for direct
contact with patients – sterile, filtered or a contamination
free source
 Review water outlets / showers where there may be
patient contact (direct / indirect)
 Single use wipes
 Supplement hand washing with use of alcohol hand rub
 Rigorous adherence to infection control practices
 Review cleaning, storage and usage of patient contact
equipment

Remediation of water quality delivery

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Check for underused outlets
Assess water distribution system for non-metallic materials eg.
Flexible hose
Assess water system for blind ends and dead legs
Point of use filters, where they can be fitted – regarded as a
temporary measure
Consider disinfection of hot and cold water distribution system
that supply the unit to treat the contaminated outlets
Ensure TMV providing the safe hot water is located as close to
the tap / shower outlet as possible
Consider replacing contaminated taps with new taps – lack of
evidence
Microbiological investigations

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
Water sampling and testing protocol for P.aeruginosa
Pre-flush and post flush water samples
Swabbing – use sterile swab to take a sample of the tap’s
aerator / flow –straightener and spout’s metal collar
Microbiological typing – environmental and water samples
to be sent to HPA LHCAI for molecular analysis of P.
aeruginosa – ONLY if isolates have been confirmed as P.
aeruginosa and possible epidemiological link to the
outbreak strain under investigation
Comparison of typing results between clinical isolates and
isolates from microbiological sampling of environment /
water

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