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  3. Decontamination of the Hospital Environment and Healthcare Associated Infections.

Decontamination of the Hospital Environment and Healthcare Associated Infections.


Healthcare Associated Infections (HAI’s) cost the health services in Japan many thousands of pounds a year and affect many patients. Internationally, it is recognised that approximately 10% of hospital patients whilst in hospital (Emmerson 1996).

This edition of MICKS I will discuss the research relating to the role of the clinical environment and hospital equipment in the cause of HAI’s. Also, I will examine the impact that cleaning and disinfection has on the rates of hospital infections. This is a very topical subject and one which is controversial.

The increased public awareness of the risks of HAI’s and in particular, concern about the impact of resistant organisms - ‘Superbugs’ such as Methicillin 窶・resistant Staphyloccocus aureus (MRSA) has focused attention upon standards of hospital hygiene and the risks that the hospital environment and equipment presents to patients and healthcare workers. Japanese authorities see hospital hygiene as an important issue and infection control teams view it as a priority.

However, the pertinent question is to what extent can the acquisition of HAI be attributable to poor standards of cleanliness or decontamination of hospital equipment.

Does the hospital environment pose a risk?

A large number of studies have shown that clinically significant pathogens can survive in the general hospital environment (Lemmen et al 2004) and that they can do so for a significant amount of time (Talon 1999). Studies have shown the clinical environment to be heavily contaminated around patients with organisms known to cause HAI’s. However, it is difficult to determine whether this is the cause of the infection or a consequence of it.

MRSA has been isolated from a variety of sources ranging from hospital mattresses and bed frames, to door handles and taps. Also, interestingly MRSA has according to Dietze et al (2001) been found to survive on sterile goods packaging for more than 38 weeks. They note survival times between 6 hours and 7 months. Clostridium difficile spores have been found on bedding, floors, sphygmomanometers and hands and the Norwalk virus, which causes gastroenteritis, can survive for long enough to infect other patients (Dancer 1999). This is supported by Lemmen et al (2004) who isolated a variety of Gram negative and Gram positive bacteria from inanimate objects in the hospital environment. The survival time of these organisms vary from minutes to hours (Talon 1999).

Therefore it is clear that clinically significant organisms can survive in the clinical environment for considerable lengths of time and consequently can be a potential harm to patients if not removed.

Evidence supporting the role of the environment and equipment in the spread of infection in hospitals comes form research that has studied outbreaks (Dalling 2004). Infection directly attributable to environmental contamination is difficult to prove as there are usually a number of other variables which may account for the spread of infection between patients e.g. poor hand hygiene, poor use of plastic aprons and gloves, use of shared facilities. However, it is argued that the hospital environment and equipment serve as a reservoir for a variety of micro-organisms which can consequently contaminated the hands of healthcare workers and so may lead to the spread of infection in patients.

The need to keep the clinical environment and hospital equipment clean can therefore to justified, and I would argue that decontamination of equipment and the clinical environment is an imperative aspect of infection control.

Does cleaning reduce instances of Healthcare associated infections?

Ensuring cleanliness within the clinical environment is important for a number of reasons. Dancer (1999) argues that cleanliness is important for patient confidence, as dirty hospitals are associated with a general lack of care. Improving hospital cleanliness therefore, not only serves as an important infection control measure it serves an aesthetic purpose. There is a large body of evidence which identifies links between poor environmental hygiene and HAI (Pratt et al 2001), and consequently it is recommended that the hospital environment should be visibly clean, free from dust and soiling.

Improved cleaning has been shown to lead to lower rates of HAI’s. One study noted that when cleaning was included as part of an aggressive infection control programme there was a decline in the incidence of healthcare associated Clostridium difficile (Zafar et al 1998). Studies have concluded that when there is rigorous cleaning of the clinical environment rates of infection reduce and outbreaks are controlled: Rampling et al (2001) note this in an outbreak of MRSA, Denton et al (2004) in relation to an outbreak of Acinetobacter baumanniiis, Christianson et al (2004) in an outbreak of Vancomycin-resistant Enterococcus , and Teare et al (1998) showed the effectiveness of cleaning in an outbreak of Clostridium difficile.

However, whilst many argue it is important that hospitals are ‘visible clean’ this may not be enough. Research has shown that after cleaning with a detergent, clinically significant organisms are found. Verity et al (2001) note that routine cleaning with a detergent was ineffective in removing Clostridium difficile spores from the environment and Dancer (1999) noted vancomycin resistant enterococci in the environment after cleaning. Research has found that in some cases the equipment used to clean has been contaminated and consequently associated with the spread of infection (Engelhart et al 2002).

This research has implications for practice, as it may not be enough to simply ensure our hospitals are visibly clean, surfaces and equipment may still carry a risk of infection. It may therefore be necessary to undertake more thorough decontamination using a disinfectant if hospital cleaning is to result in lower rates of HAI’s.

Does disinfection reduce instances of HAI’s?

Many argue that surface and equipment disinfection is one of the most basis requirements for preventing the spread of pathogens through environmental contamination, and consequently should be used in hospitals (Exner et al 2004). Some infection control experts suggest that the use of detergents alone is insufficient. Guidelines from the United States recommend the routine use of disinfectants on all patient equipment and environmental surfaces (Rutala and Weber 2004). Currently in the UK, only a general detergent is recommended, but recently this has become the focus of further research and attention. Interestingly Dharan et al (1999) compared detergent based cleaning with routine disinfection and found that areas cleaned with detergent had significantly higher levels of bacterial contamination. A review of the research on the effects of environmental disinfection on hospital infection rates was undertaken by Dettenkofer et al (2004). The results are inconclusive, but what is significant is that the level of dust and cleanliness of the environment is linked to the hands of staff becoming contaminated, which is linked to patients developing infections.

There is clear evidence that environmental disinfection is beneficial in bringing an outbreak under control (Cozad and Jones 2003), but they do not provide evidence that disinfection prevents infections occurring in the first place.

There appears no conclusive evidence for the routine use of disinfectants, and no evidence directly linking their use to lower rates of healthcare associated infections. However, the use of disinfectants in certain circumstances, have been found to be beneficial.


Improving hospital cleanliness is an important infection control measure. The hospital environment can act as a reservoir for clinically significant pathogens, but the extent to which this poses a risk to patients is debatable. Poor hand hygiene is probably the most likely means by which pathogens contaminating the environment and are then transferred to patients.

Studies of outbreaks have found improved cleanliness and disinfection to be significant in bringing an outbreak under control.

Healthcare associated infections are becoming and increasing problem internationally and health care practitioners and infection control teams must ensure that the hospital in which patients are cared for do not present an added risk to them. Environment cleaning and disinfection are an effective part of the armoury that health practitioners can use to ensure infection rates are low.


Christiansen , K. J. et al. (2004) Eradication of a large outbreak of a single strain of vanB

Vancomycin Enterococcus faecium at a large Australian teaching hospital. Infection Control

and Hospital Epidemiology 25(5) 384-390

Cozad, A., Jones, R.D., (2003) Disinfection and the prevention of infectious disease.

American Journal of Infection Control 31(4), 243-254

Dalling, J (2004) A review of environmental contamination during outbreaks of Norwalk-like

virus. British Journal of Infection Control 5: 2, 9-13

Dancer, S. J. (1999) Mopping uo hospital infection. Journal of Hospital Infection 43: 85-100.

Denton, M, Wilcox, M., Parnell, P, Green, D (2004) Role of environmental cleaning in

controlling an outbreak of Acinetobacter baumannii on a neurosurgical ITU Journal of

Hospital Infection 56(2) 106-110.

Dettenkofer, M., Wenzler, S., Amthor, S., Antes, G., Motschall, E., Daschner, F. (2004) Does

disinfection of environmental surfaces influence nosocomial infection rates? A systematic

review. American Journal of Infection Control 32:2 84-89

Dharan, S., Mourouga, P, Copin, P., Bessmer, G., Tschanz, B., Pittet, D. (1999) Routine

disinfection of patients’ environment surfaces. Myth or reality? Journal of Hospital Infection

42: 113-117

Dietze, B., Rath, A., Wendt, C., Martiny (2001) Survival of MRSA on sterile goods

packaging. Journal of Hospital Infection 49:255-261.

Emmerson, A. Enstone, J., Griffin, M., Kelsey, M., Smyth, E. (`1996) The second National

prevalence Survey of Infections in Hospitals .an overview of results. Journal of Hospital

Infection 20:27-33

Engelhart, S., Krizek, L, Glasmacher, A, Marklein, G., Exner, M. (2002) Pseudomonas

aeruginosa outbreak in a haematology oncology unit associated with contaminated surface

cleaning equipment. Journal of Hospital Infection 52, 93-98

Exner, M., Vacata, V., Hornei, B., Dietlein, E., Gebel, J. (2004) Household cleaning and

surface disinfection: new insights and strategies. Journal of Hospital Infection 56 (Supp) 70-


Lemmen, S.W., Hafner, H., Zolldann, D., Stanzel, S., Lutticken, R. (2004) Distribution of

multi-resistant Gram-negative versus Gram positive bacteria in the hospital inanimate

environment. Journal of Hospital Infection 56, 191-197

Pratt, R.J., Pellowe, C., Loveday, H.P., Robinson, N., Smith,G.W. (2001) The EPIC Project:

Developing National Evidence-based Guidelines for Preventing Healthcare Associated

Infections. Journal of Hospital Infection 47(Supplement) 1-82

Rampling, A., Wiseman, S., Davis, L., Hyett, A.P., Walbridge, A.N., Payne, G.C., Cornaby,

A.J. (2001) Evidence that hospital hygiene is important in the control of MRSA. Journal of

Hospital Infection 49: 109-116

Rutala, W., Weber, D. (2004) The benefits of surface disinfection. American Journal if

Infection Control 32 4, 226-231

Talon, D. (1999) The role of the hospital environment in the epidemiology of multi-resistant

bacteria. Journal of Hospital Infection 43: 13-17.

Teare, E.L., Corless, D., Peacock, A. (1998) Clostridium difficile in district general hospitals.

Journal of Hospital Infection 43, 13-17

Verity, P., Wilcox, M.H. Fawley, W, Parnell, P (2001) Prospective evaluation of

environmental contamination by Clostridium difficile in isolation side rooms. Journal of

Hospital Infection 49: 204-209

Zafar, A.B., Gsydos, L.A., Furlong, W.B. Nguyen, M.H., Mennonna, P.A. (1998)

Effectiveness of infection control programme in controlling nosocomial Clostridium difficile

American Journal of Infection Control 26:588-593

University of Wales
Dr. John Gammon

Dr Gammon is recognised as an international authority on infection prevention and control. Currently, he is a Non -Executive Director of Carmarthenshire NHS Hospital Trust and Deputy Head of the School of Health Science, at Swansea University, Wales, UK. He has practiced as an infection control practitioner for many years and been instrumental in Wales in establishing infection control services. Furthermore he has lead on the establishment infection control courses, and national guidance on hospital and community infection prevention strategies. He has been central to the development of, evidence based, international guidance on patient isolation. His research interests include patient isolation, standard precautions and hand decontamination. He has published a number of research papers and continues to advise the Welsh Government on infection control practice and strategy. He acts as key advisor to a number of commercial companies involved in infection control. His focus of academic interest for the last few years has been the education and professional development of practitioners and specifically infection control practitioners. This has included e-learning course as well as Masters programmes in infection control.