Importance Of The Environment In MRSA Acquisitions The Case For Hospital Cleaning
By Stephanie J. Dancer, Director, Department of Microbiology, Southern General Hospital, Glasgow (Editor, Journal of Hospital Infection)

There is much concern over the state of hygiene in hospitals. The general public seem to associate visibly dirty wards with increasing rates of methicillin-resistant Staphylococcus aureus (MRSA) acquisition, but historically there has been little evidence that the environment is important in endemic hospital-acquired infection. This premise has been challenged since the increase in MRSA in hospitals in the past decade. Because a clean environment is usually taken for granted, it is not surprising that there is little evidence to show that cleanliness could be an important control factor in the spread of MRSA. Furthermore, the measurement of how clean a hospital is other than by visual assessment, which is both subjective and inaccurate, is difficult because such an assessment does not necessarily correlate with microbiological risk.

The issue of hospital-acquired infections in compounded by the current politically generated drive to reduce waiting lists. Hospitals are crowded with sick people in close proximity to one another, even though years of work in infection control have shown us that patients pass their microorganisms to those nearby. This was first recognized by Florence Nightingale in the 19th Century, at least 10 years before the advent of bacteriology. She concluded that the use of small, separate rooms could have prevented the high rate of mortality in maternity cases after an outbreak of erysipelas at a midwife training school. However, lack of isolation facilities and continued pressure on the availability of beds provide a serious challenge to standard principles of infection control.

A recent study has confirmed an association between MRSA bacteraemia rates, bed occupancies and even bed turnover times. However, not only do governmental faculties not understand the link between visible dirt and the presence of pathogenic microorganisms, they also do not support the premise that crowded hospitals facilitate the spread of infection.

Only a few studies provide evidence that cleaning reduces the risk of acquiring MRSA in health-care institutions. There is another way, however, of justifying cleaning as a useful control strategy for MRSA. We already have evidence to support each of the individual components of the staphylococcal transmission cycle between patients, staff and the inanimate environment. Much of the work on coagulase-positive staphylococcus, originally done 50 years ago, is as relevant for MRSA as it is for its susceptible predecessor.

The epidemiological properties of S. aureus, whether methicillin resistant or not, remain the same. One difference between the hospital staphylococcus of the 1960s and the current MRSA strains is that isoxazolyl penicillins (e.g. flucloxacillin) quickly cured patients with S. aureus infections before it had a chance to spread to other patients or into the environment. Additionally, the hospitals received more cleaning at that time, since they had not been exposed to today’s emphasis on cost cutting. Of course, we do not have a quick cure for MRSA – currently available drugs are either toxic or expensive, or relatively inefficient, and most have to be given parenterally. Resistance has already been shown for newly released agents. This condemns colonised or mildly infected patients to conservative management only, thus enhancing their risk for future sepsis as well as providing the organism with an opportunity for dispersal throughout the environment and to others.

Even if the epidemiology of staphylococcus has not changed over the years, there are, however, differences in the type of patients that are seen today and the clinical environments in which they are nursed. Patients are older, immunologically weaker, and are subjected to far more invasive procedures and devices than the patients of 50 years ago. Furthermore, there has been a huge influx of electronic equipment into the near-patient vicinity, providing more hand-touch sites that require a greater degree of sophisticated cleaning attention. Certain liquid cleaning agents would damage many items of medical and nursing equipment. All of these differences could have contributed towards an increase in MRSA acquisition in modern hospitals.

Given the preoccupation with hospital budgets, we need another strategy for tackling the presence of MRSA in our hospitals other than campaigning for more cleaning hours. Visual appearance is an unreliable guide to the presence of pathogenic microbes and, indeed, rates of infection. Perhaps targeting the areas in a hospital that constitute the highest risk for the presence of MRSA would be a feasible option in the short term. Buffing the floors in outpatient departments might improve the appearance of the waiting areas, but patients do not generally acquire MRSA from floors. The greatest risk for patients is contaminated near-patient hand-touch sites in clinical areas. This is borne out by studies that have seeded viral or other molecular fragments onto a door handle or a telephone, and then charted their movements over the course of a few days. Such studies show the importance of sites that human hands touch more frequently, and can be used as an indicator for what might happen regarding the spread of MRSA.

Cleaners (Environmental Services) should be included as an integral part of the infection-control team. They should be allocated more cleaning hours from the hospital budget, particularly when there is evidence for substantial savings. Cost of drugs alone to treat MRSA, without even considering the costs of extended bed-stay for infected patients, justifies targeting domestic resources in clinical areas. Furthermore, the increasing prevalence of MRSA and other multiple-drug-resistant bacteria in hospitals support the prioritization of cleaning and other control measures before definitive validation. We should have faith that we are doing the right thing.

If cleaner hospitals ultimately reduced the number of patients acquiring healthcare-associated MRSA, there should be a concomitant reduction of MRSA in the community, because acquisition in hospital invariably leads to patients taking the infection home. A cleaner culture adopted by hospitals might impinge on the community in other ways. The general public should consider their own attitude to hygiene when cleaning themselves and their homes, and when preparing food. Any societal erosion of hygiene might be caused by complacency emanating from the discovery of antimicrobial agents. This issue requires urgent appraisal, since the increasing numbers of community strains of MRSA have been associated with hygiene issues and more frequent antibiotic consumption. These community strains are more virulent than established hospital strains and have already shown their potential to start hospital outbreaks.

People look towards hospitals to treat the sick and set appropriate standards of hygiene. But modern hospitals are often cluttered, overcrowded, and visibly dirty. Cleaning staff and hours have been drastically reduced over the past decade. Even if scientific validation is obtained, regenerating interest in the removal of dirt in the 21st Century will require monumental effort.

Aside from its low status, cleaning costs money and it is hard work. It is difficult to measure the process of cleaning and its impact, or assess it against the risk of acquiring MRSA. We should take the half-century’s worth of data that we have and try to change things while we still can. We do not yet know exactly what impact cleaning could have on control, but this ignorance should not be used as an excuse for doing nothing.

(This article is edited from a Review published in Lancet. For a copy of the entire article, or to obtain Dr. Dancer’s contact information, contact Nicole Kenny at This e-mail address is being protected from spam bots, you need JavaScript enabled to view it ). '; document.write( '' ); document.write( addy_text83704 ); document.write( '<\/a>' ); //-->\n This e-mail address is being protected from spam bots, you need JavaScript enabled to view it