Michael.Kelsey@nhs.net. When did pseudomonas become important? Rogers, D. E. (1959). "The...

Michael.Kelsey@nhs.net

When did pseudomonas become important?

Rogers, D. E. (1959). "The changing pattern of life-threatening microbial disease." N Engl J Med 261: 677-683.

• Compared microbial causes of death between 1938-1940 with 1957-1958

• E. coli deaths “superseded by an unusual pathogen, Pseudomonas aeruginosa”

• 1938-40 93% of infections causing death arose in the community

• 1957-58 53% hospital acquired

Is there a problem with P. aeruginosa?

Total numbers & P. aeruginosa bacteraemias in England

20,000

22,000

24,000

26,000

28,000

30,000

32,000

34,000

36,000

2006

1

2006

2

2006

3

2006

4

2007

1

2007

2

2007

3

2007

4

2008

1

2008

2

2008

3

2008

4

2009

1

2009

2

2009

3

2009

4

2010

1

2010

2

2010

3

2010

4

500

550

600

650

700

750

800

850

900

950

All bacteraemias

P. aeruginosa bacteraemias

2006-10 by quarter

Looked at another wayQuarter P. aeruginosa All bacteraemia % P. aeruginosa

2006-1 615 28,781 2.1%

2006-2 632 29,430 2.1%

2006-3 840 30,552 2.7%

2006-4 732 28,816 2.5%

2007-1 694 31,440 2.2%

2007-2 677 31,302 2.2%

2007-3 825 34,984 2.4%

2007-4 838 35,192 2.4%

2008-1 729 33,129 2.2%

2008-2 738 32,941 2.2%

2008-3 849 32,656 2.6%

2008-4 750 32,888 2.3%

2009-1 680 33,303 2.0%

2009-2 702 32,385 2.2%

2009-3 892 31,728 2.8%

2009-4 907 31,512 2.9%

2010-1 656 31,327 2.1%

2010-2 713 30,178 2.4%

2010-3 895 30,383 2.9%

2010-4 867 32,472 2.7%

Grand Total 15,231 635,399 2.4%

And looked at a 3rd way

Between 2004 & 2008 the number of Pseudomonal bacteraemias increased by 24%

http://www.rqia.org.uk/cms_resources/HEIG%20-%20Final%20Copy%20of%20Tap%20Study%20Report_att1_HPA%20NI%20Tap%20Study%20Report.pdf

http://www.rqia.org.uk/publications/rqia_reviews.cfm

A new source of P. aeruginosa

Wilson, M. G., R. C. Nelson, et al. (1961). "New source of Pseudomonas aeruginosa in a nursery." JAMA 175: 1146-1148.

Welsh estates alert the home countries

O.C. Durojaiye, N. Carbarns, S. Murray, S. Majumdar. Journal of Hospital Infection 78 (2011) 152–159. Outbreak of multidrug-resistant Pseudomonas aeruginosa in an intensive care unit.

6 August 2010From the Chief Medical Officer

Welsh Assembly Llywodraeth CynulliadGovernment CymruCathays Park Parc Cathays Cardiff CaerdyddCF10 3NQ CF10 3NQ

CMO(2010)13WATER SOURCES AND POTENTIAL FOR CROSS INFECTION FROM TAPS AND SINKS

Water quality at the point of entry into NHS premises

“drinking water must be wholesome at the time of supply”

The legislation Water Supply (Water Quality) Regulations 2000 (as amended in

2001, 2007 and 2010) , which implemented the European Council Drinking Water Directive 98/83/EC 1998.

Compliance with the quality standards is overseen by the Drinking Water Inspectorate

Microbiological standards or “Prescribed Concentrations or Values” (PCV) Escherichia coli and Enterococci

The standard is 0 per 100ml. Clostridium perfringens

The standard is 0 per 100ml. Coliform bacteria

The standard is 0 per 100ml. Colony Counts

The standard is ‘no abnormal change’# -”taste and odor problems”

#"no significant variation and no abnormal change is when all the results obtained in the two years (or in the results of the last 12 samples where less than this number has been taken in two years) are within plus or minus one order of magnitude of the mean for that zone“

Anon 1934. The bacteriological examination of water supplies, HMSO, London “Report 71”

Guidance on pseudomonads

Drinking Water Safety-Guidance to health and water professionals, 2009 (www.dwi.gov.uk)

HTM 04-01, 2006 Provided water is supplied from the public mains and its quality is

preserved by correct design, installation and maintenance, it can be regarded as microbiologically acceptable for use.Minimum hot water temp 55°C at furthest point, delivered at 41°Ctwice weekly flushing

WHO – Water Safety in Buildings, 2011 Hospitals need-water safety plans; higher quality than

drinking water; water treatment at the point of entry; pasteurisation of hot water systems >70°C

Other countries France

Colony counts and “nuisance” organisms

total viable counts (TVC) aerobic colony counts (ACC)

and heterotrophic plate counts

(HPC)

A heterotroph is an organism that cannot fix carbon and uses organic carbon for growth.

Sources of utilisable carbon in a hospital water distribution system

Provider surface bore hole

Added in distribution materials from constructionWater Regulation Advisory Schemes (http://www.wras.co.uk)

Water Supply (Water Fitings) Regs 1999

the unintended

Carbon content will vary in place and time

And then there is the plumbing

The natural history of pseudomonas and faucets 1

Water contains sufficient organic utilisable carbon for heterotrophic growth.

P. aeruginosa is present in the provider supply, or poor separation of clean & dirty contaminates the faucet,

or P. aeruginosa is introduced at installation/commissioning.

Biofilm is formed and persists and gives rise to: planktonic & sessile populations

Factors contributing to contamination 1 Concern for hand hygiene increased the

number of outlets and: reduces flushing increases relative dead legs

Delays between installation-commissioning-use

Circulation of hot water is between 60°C & 50°C

Aerators and coarse filters increase surface area

Why does the Flying Fickle Finger of Fait also point at Thermostatic Mixing Valves(TMVs)?

Factors contributing to contamination- are TMVs and infrared taps an issue?

Contamination occurs within the last 2 metres of the distribution system

TMVs contain larger surface areas of polymers which will support growth through liberation of utilisable carbon

Mixed water exiting a TMV is not hot enough to pasteurise

Flows are reduced and less turbulence to scour biofilm P. aeruginosa comes pre-installed Installation may be incorrect Infra red switching taps contain polymer diaphragms

adding to the utilisable carbon load

What has been done about the problem?

Produced interim guidance to assist in the prevention of the problem Organisation-water safety plan Risk assessment Water testing

Produce an appendix to HTM 04-01: The control of Legionella, hygiene, “safe” hot water, cold water and drinking water systems

http://www.dh.gov.uk/health/2013/03/pseudomonas-addendum/

What needs still to be done

revise HSE L8 document to take into account water quality and opportunistic infection other than Legionella.

Establish a standard for water AT THE POINT OF USE in healthcare premises. Hygiene Washer disinfectors Pharmacies

And that’s all I have time for folks

Still to be achieved in water safety

Encourage the industry to seek engineering solutions to the problem of tap & TMV design

Commission research Materials Growth Biofilm

Utilisable carbon sources added from materials in buildings

Water Regulation Advisory Schemes (http://www.wras.co.uk) Water Supply (Water Fitings) Regs 1999

fitting approval showers thermostatic mixer valves

(Buildcert, MES D08)

material approval BS 6920-2.4

England's DH responds

Diagram illustrating the components of a thermostatic mixing valve (TMV) & faucet

Hot water circulates continuously with a minimum temperature at the most distant part of 55°C. On return to the heat exchanger or calorifier the temperature must not be below 50°C.

Cold water distribution temperature must not exceed 20°C as this is the temperature above which Legionella will proliferate.

An adjustable thermostatic regulator that will blend incoming hot and cold water supplies to achieve an output at the faucet of between 41 and 43°C. The designs will require water to be provided above a certain pressureto function correctly.

The tap controls the flow at the faucet. Where these are operated by infrared sensors and an electronic solenoid, additional polymer surfaces are introduced together with a residual volume at a temperature that will encourage growth.

{The distance between the TMV and the tap or faucet can be critical. Water leaving the TMV is at most 43°C which is not sufficient to pasteurise. It will rapidly fall to ambient temperature and if contaminated will allow the proliferation of biofilm. Some devices incorporate the TMV within the tap design to minimise this distance.

The “flow straightener”, inserted at the tip of the faucet to reduce splashing. Often complex designs and are where scale and biofilm accumulate. They are always the leading “suspect” where there is a problem with P. aeruginosa. They are removable and manufacturers are producing designs of spout without them. The combination of water, air and utilisable carbon make them irisistable to P. aeruginosa.