How to control the spread of MRSA
An EMS provider’s guide to stopping staph
By Kelly Grayson
Staphylococcus: It’s everywhere you look.
In the decades-old battle between antibiotics and bacteria, bacteria always seem to find a way to adapt and come back stronger. A big reason for this is the indiscriminate prescribing of antibiotics for viral syndromes, which are unaffected by antibiotics. The normal flora and fauna of our bodies, or sub-acute infections we didn’t even know we had, are exposed to a broad array of antibiotic drugs, and inevitably, some of them adapt and become resistant.
However, we can’t lay all the blame at the feet of our physicians. Patients demand treatment, and are often unwilling to accept the unwelcome truth that the best treatment course for their illness is to rest, rehydrate, and let their immune system do its job. They demand medicine, and if they don’t get it, they’ll find another doctor less principled in his prescribing practices.
Complicating matters is the fact that many patients simply ignore their medication instructions. Rather than take the full course of antibiotics, which is necessary to assure complete eradication of the offending pathogen, they often stop taking their antibiotics the moment they start to feel better. The weaker bacteria are killed off, and their hardier brethren remain to pass on their resistant qualities to the next generation. Such is how drug-resistant bacteria are born.
Dangerous to the EMS provider
One of more prevalent strains of drug-resistant bacteria today is methicillin-resistant Staphylococcus aureus, commonly known as MRSA. Staphylococcus aureus is part of the natural flora and fauna of the human body, present on the skin and in the nasal passages of roughly 20 percent of the population. Staph is an exceptionally hardy bacterium, able to survive for weeks or even months on dry environmental surfaces.[2,3]
Although staph can be non-pathogenic, it is one of the more common causes of skin infections and upper respiratory infections. Not only is staph endemic in the United States and abroad, its prevalence exploded in health care settings in the 1990s. A number of studies show that ambulances are a significant potential reservoir of the disease.
In one recent study of Chicago-area ambulances, Staphyloccus was found in 69 percent of the ambulances in the study, with 12 percent of those samples determined to be one of the methicillin-resistant strains. Another study showed 46% of the ambulances contaminated with MRSA.
Like any infectious pathogen, the key to controlling MRSA is in limiting its spread. To do this, EMS providers should be able to recognize the signs and symptoms of staph infection, including the patients most at risk; practice good personal hygiene; and thoroughly decontaminate the ambulance module and other environmental surfaces after each call.
Populations at risk
In the past, MRSA was most prevalent in health care environments. The number of invasive procedures performed and the compromised immune systems common in many of these patients combined to make hospitals, inpatient care facilities and ambulances ideal reservoirs for MRSA contamination.
However, since the 1990s, prevalence of community-acquired MRSA contamination has soared, and now all populations are at risk. Risk factors for community-acquired MRSA include:
- Close skin-to-skin contact
- Openings in the skin such as cuts or abrasions
- Contaminated items and surfaces
- Crowded living conditions
- Poor hygiene
As such, environments where one or more of these risk factors are present make them especially vulnerable to community-acquired MRSA contamination. These environments include:
- Athletic facilities
- Military barracks
- Correctional facilities
- Daycare centers
Hygiene and decontamination practices
Body substance isolation has been the infection control standard taught in EMT textbooks for many years. However, the skin-to-skin contamination possible with MRSA and the droplet inhalation potential for SARS and swine flu have necessitated revision of the old BSI guidelines. These comprehensive new guidelines now are called Standard Precautions:
- Hand hygiene
- Use of PPE
- Environmental cleaning and safe handling of potentially contaminated equipment
- Safe injection practices
- Respiratory hygiene and cough etiquette
Of these elements, the first three have the greatest potential to limit the spread of MRSA. It is important to understand that MRSA contamination is possible even through contact with unbroken skin. As such, hand hygiene, use of PPE and environmental decontamination are of paramount importance.
Regular hand washing and use of alcohol-based hand rubs are typically all that is necessary. Alcohol-based rubs and lotions are recommended as the primary source of hand hygiene, both for its broader spectrum of effectiveness, and because its ease of use compared to hand washing is thought to increase compliance, particularly at bedside. Forty to sixty seconds of hand washing is recommended if hands are visibly soiled with blood, soil or bodily fluids, or after caring for patients with known or suspected infectious diarrhea, such as novovirus or C. difficile.
Alcohol-based rubs should be used in the following situations:
- Before touching a patient, even if gloves will be worn
- Before exiting the patient care area after touching the patient or immediate environment
- After contact with body fluids or wound dressings
- Prior to performing IV cannulation or injection
- If hands will be moving from a contaminated-body site to a clean-body site
- After glove removal
Forty to sixty seconds of hand washing — taking care to avoid recontamination through door handles, faucet handles or paper towel dispenser — should be performed in the following situations:
- After contacting patients known or suspected to have infectious diarrhea
- Visibly soiled hands
Personal protective equipment
PPE generally consists of non-porous barrier devices, and should be worn whenever patient contact is anticipated. The extent of PPE worn will depend upon the specific nature of the call, but at minimum gloves should be worn for every patient contact. Although standard precautions do not require gloves for contact with intact skin, our skin is rarely 100% intact, and many infectious pathogens, such as MRSA, can live on the surface of intact skin. It is only prudent to wear gloves for every patient encounter.
Cleaning of the patient care environment generally consists of three levels of precautions:
- Cleaning: the removal of visible soil and contaminants, using detergent or chemical cleaners, and vigorous scrubbing. It is impossible to disinfect an area that still bears visible soiling.
- Disinfection: typically involves a chemical agent to remove all pathogenic microorganisms, but not typically bacterial spores.
- Sterilization: inactivation and removal of all microbial forms, including spores, utilizing boiling water or steam, high pressure or chemicals, or some combination of the three.
Generally, our methods of environmental decontamination in the prehospital realm are limited to cleaning and disinfection. Put particular emphasis on surfaces in direct contact with the patient such as cot mattress and rails, and surfaces in close proximity to the patient that are frequently touched, such as cabinet and exterior door latches, and work surfaces. In ambulances, often the most contaminated area is the action area to the right of the airway seat, where the on-board suction is typically mounted.
As always, proper hand hygiene is required during and after decontamination of patient care equipment and the ambulance module. General guidelines for environmental decontamination include:
- Use disposable whenever possible.
- Critical items (e.g., surgical instruments) are objects that enter sterile tissue or the vascular system and must be sterile prior to use.
- Semi-critical items (e.g., laryngoscopes) that contact mucous membranes or non-intact skin require high-level disinfection prior to reuse.
- Noncritical items (e.g., blood pressure cuffs) that may come in contact with intact skin but not mucous membranes should undergo low-level or intermediate-level disinfection depending on the nature and degree of contamination.
Environmental surfaces (e.g., floors, walls) are those that generally do not contact the patient during delivery of care. Cleaning may be all that is needed for the management of these surfaces, but if disinfection is indicated, low-level disinfection is appropriate.
Use an EPA-registered hospital disinfectant for low-level or intermediate-level disinfection. While most of the labels on these products specify a minimum contact time of 10 minutes, multiple studies have demonstrated efficacy of these disinfectants with a contact time of 60 seconds.
With the rise of community-acquired MRSA infections, all of the population is at risk. However, good hygiene, fresh gloves and vigorous disinfection before and after every call can greatly limit your risk of MRSA infection — and help prevent the spread of MRSA to your patients.
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2. Cimolai N (July 2008). "MRSA and the environment: implications for comprehensive control measures.” European Journal of Clinical Microbiology and Infectious Disease. 27 (7): 481–93.
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