Fighting MRSA with conventional thinking
September 19, 2010
We are entering a new era, when proper cleaning may become an essential defense against serious, even life-threatening infections.
Proper cleaning is clearly associated with health since many common infections, such as cold viruses, are transmitted through direct contact and allergens that trigger asthma as well as other allergic reactions may accumulate if housekeeping is not sufficient.
For the most part, proper cleaning creates a healthier environment that reduces the risk of common, less serious diseases.
Cleaning as a lifeline
There are times when proper cleaning may be lifesaving.
This has been most obvious in hospitals and health care facilities.
Now, with the arrival of MRSA, it may be true for anywhere we live, work, and play.
MRSA is the abbreviation for methicillin-resistant Staphylococcus aureus, an emerging infection that, while not quite a “superbug,” has the potential to cause devastating infections and has even morphed into a particularly dangerous strain, USA 300, which is transmitted by skin-to-skin contact and is resistant to multiple antibiotics, and may morph again in the future.
Briefly, MRSA is a variant of staph which has acquired resistance to the antibiotic methicillin.
How did this happen?
Bacteria acquire resistance when an antibiotic is given and before long, the resistant strains become dominant.
The infection caused by the resistant bacteria crosses over to otherwise healthy people; the now “emerging” infectious disease becomes a public health problem and new antibiotics are urgently needed to keep up with them.
MRSA is at the stage right now where it can be treated, but it is clearly becoming more common and is on its way to becoming a serious public health problem.
Along the way, MRSA picked up some nasty habits — more accurately, bad genes.
MRSA acts like a more aggressive version of staph.
Patients who have a problem with their immune systems, for example during cancer chemotherapy, may get it in the hospital and it can take many forms.
Healthy people usually get it as a skin infection, in the form of an abscess, pimple or boil on the skin and it initially resembles and is often mistaken for a spider bite.
The infection can be treated with different antibiotics if it is recognized, but treatment often takes longer.
This is why the health community is concerned about MRSA.
How MRSA travels
In hospitals, staph and now MRSA is often present in fixtures and equipment and can be carried in the noses and hands of hospital personnel.
Outside the hospital, MRSA is spread mostly by skin contact or by intravenous drug users.
It can also be carried on people’s hands, in their noses, and on contaminated objects or surfaces.
Skin-to-skin or skin-surface-skin contact transmits the bacteria, often through a cut or abrasion on the skin.
Right now, the disease is most common in medical settings and places where people live closely together or have physical contact, such as athletes, military recruits, school children and prisoners.
Furthermore, it is also on its way to becoming a sexually transmitted disease.
What is are best practices?
It is clear that staph can live for a while on the floor, on a gym mat, in a bed, in a daycare center or in hospital equipment.
Cleaning is, therefore, an important part of stopping the transmission of MRSA.
What are the best practices to prevent this and do we need to clean every building as if it were a hospital?
Fortunately, not every building needs cleaning to the same level as a hospital, but we can learn a lot from the experience of hospitals, as they are the worst-case scenarios.
Hospitals have shown us that conventional disinfection can work against MRSA, but the cleaning has to be thorough and accompanied by decontamination of the patient and shared medical equipment, avoiding sharing of towels and other personal items, and by frequent hand-washing.
Radiators, shared medical equipment, furniture, door handles, televisions, floors and other flat surfaces, ventilation duct grills, and beds were all found to be contaminated within the hospital setting.
Outbreaks of MRSA have been controlled in hospitals and day care settings for special-needs children by thorough cleaning, vacuuming dust (rather than mopping, which was found to be ineffective), and meticulous attention to hard-to-clean equipment, including the nurse-call button.
The major problem in hospitals appears to be recontamination, which has been amply demonstrated.
In settings outside the hospital, it is not possible to enforce frequent hand-washing — other than by food handlers — or to insist on decontamination of visitors.
Keep in mind when cleaning
However, cleaning and disinfection of floors, vacuuming dust with HEPA-or micron filter-fitted vacuums, careful cleaning, disinfection of shared equipment, including computer peripherals, and attention to doorknobs are practices that will reduce the risk of transmitting MRSA.
Cleaning and decontamination of bedding and clothing may require washing at 40 to 60 degrees (C) using a disinfecting agent.
Cleaning other textile materials is obviously more difficult, but MRSA has been found in carpet, clothing, and upholstered furniture.
These should be vacuumed frequently to reduce dust, which can carry MRSA and other pathogens.
Soap and water cleaning is not adequate for control of bacterial contamination by pathogens, because the process removes bacteria mechanically, and so reduces the number of bacteria rather than killing it and preventing replication.
Chemical disinfection is required for effective sanitization.
Standards for disinfection that work for staph in general will probably work for MRSA.
Cleaning cloths are always a worry because they might spread bacteria when they are reused.
Results from comparison study
Comparisons of sanitization show that all-purpose cleaning cloths sanitized with quaternary ammonium disinfectants, whether antibacterial or not, showed less capacity to carry live staph than cleaning cloths disinfected with hot water or hypochlorite (bleach), but that kitchen-type conventional fabric cloths sanitized with hot water were almost as good.
Among the various disinfectants that could be used for direct application, products containing hypochlorite, phenolic, and quaternary ammonium compounds were effective against MRSA; the authors of this study concluded that these and other commercial disinfectants were more effective than natural products, such as vinegar.
Careful attention should be paid to cleaning and disinfection of gym mats, exercise machines, showers, and floor surfaces between uses that may involve skin contact.
Spray bottles with disinfectant that can be used for convenience to spray and wipe-down should be sufficient for solid surfaces; reusable coverings may be needed for some purposes.
Soap should be provided in dispensers, preferably touch-free, rather than shared bars of soap, and hands should be dried by individual and disposable towels or by air dryer.
Frequent hand-washing with soap and hot water or hand sanitizing with an instant, alcohol-based hand sanitizer when washing facilities are not available or convenient, should be practiced and encouraged in all common public areas, such as workplaces, schools, and fitness centers.
Facilities that offer personal services, such as steam rooms, saunas, hot tubs, swimming pools, immersion tanks, and washing machines, need to be allowed to dry and also disinfected periodically.
The protocol to be followed depends on the use and directions from the manufacturer.
Protection of cleaning personnel is also important.
Hand-washing with running water, alcohol-based hand rubs, and gloves, which must be washed or disposed of regularly, are important to protect the worker as well as to break any possible chain of transmission from cleaning and maintenance activities.
The risk of reintroduction of MRSA is a huge problem in hospitals, but less so in non-hospital settings.
In hospitals, MRSA is common and reintroduction is frequent.
Outside the hospital, it is still, fortunately, less common and reintroduction should be infrequent unless there is an unusually high prevalence of MRSA in the population, such as in prisons.
In any case, the risk of reintroduction will be a direct function of the frequency of skin-to-skin or skin-to-surface-to-skin contact.
Therefore, the cleaning schedule should be adjusted according to the level of activity, with more frequent disinfection the busier the room or facility is.
Evidence-derived standards are not yet available to provide more accurate guidance.
Dr. Tee L. Guidotti is a physician specializing in occupational and environmental medicine and pulmonary disease. He is professor and chairman of the Department of Environmental and Occupational Health in the School of Public Health and Health Services, George Washington University.