Most of the following information came from Dr. Jaime Carrizosa's presentation at the January 26, 2008, MRSA Symposium.
Staph aureus & MRSA:
Methicillin resistant Staph aureus (MRSA) infections have received a lot of media attention recently, but MRSA infections are not new. MRSA is a common bacteria that has been around for a long time. MRSA has become increasingly dangerous because it has acquired genes that make it more resistant to antibiotics.
MRSA is particularly worrisome because it is resistant to the common antibiotic methicillin, and because some patients can get very ill (and even die) from severe MRSA infections. But we still have antibiotics other than methicillin to treat MRSA infections.
And not all Staph aureus bacteria (S. aureus) are resistant to methicillin.
S. aureus resistance:
In intensive care units the percent of S. aureus resistant to antiobiotics has increased from 37% in 1995 to 60% in 2004. This increased resistance is being seen worldwide. However, we still have both oral and intravenous antibiotics that can treat MRSA infections.
Where S. aureus is found:
- 2/3 to 3/4 of us are colonized by S. aureus at some point
- 20% to 50% of us are colonized at any given time
- 0% - 20% of us are persistently colonized
- The nose is the most common site of colonization
- 80% to 90% of serious Staph infections come from bacteria a person has on their skin or in their system
S. aureus is the most common cause of:
- Heart infections (38%)
- Infections patients get while being in a healthcare facility (13%)
- Skin and soft tissue infections (20%)
- Infections in the bones or joints
- Infections in the blood stream
Types of S. aureus infections:
- Methicillin sensitive Staph aureus (MSSA)
- Methicillin resistant Staph aureus (MRSA); which includes:
- Hospital Acquired MRSA (HA-MRSA)
- Community-Acquired MRSA (CA-MRSA)
Percentage of all infections that are S.aureus:
- MSSA 2% - 10%
- MRSA 5% - 30%
Community-Acquired MRSA (CA-MRSA)
CA-MRSA is the term used for MRSA infections that get started outside the hospital setting. These infections usually presents as a skin infections.
Many patients with CA-MRSA will come in for a "spider bite", but the only spider bite that causes a skin infection is the brown recluse spider, and bites from the brown recluse are exceedingly rare in Florida. Physicians should consider your "spider bite" to be CA-MRSA until it is proven otherwise!
Treatment of CA-MRSA:
- 75% - 80% of patients with CA-MRSA present with skin infections
- Many cases can be treated with incision and drainage only - without antibiotics
- If an antibiotic is required, options for treating CA-MRSA in adults include:
- Trimethoprim/sulpha DS - 1 to 2 twice daily for 7-10 days
- Minocycline or Doxycycline 100mg twice daily for 7-10 days
- Clindomycin 300-450mg twice daily for 7-10 days (resistance to this is forming)
Pediatric oral antibiotic treatment options:
- Trimethoprim 8-12mg + sulpha 40-60mg/kg/day in 2 doses for 7-10 days
- Clindamycin 10-20mg/kg/day in 3-4 doses for 7-10 days (resistance is becoming more frequent)
Treatment of recurrent CA-MRSA furunculosis (boils):
- There is little evidence that there is a long-term benefit to trying to get rid of CA-MRSA in a patient who is a chronic carrier. Potential toxicity of agents, their cost, and the potential for creating resistance will need to be considered by your doctor.
Options for treatment include:
- A combination of topical, mucosal, and systemic antibiotics, such as oral Trimethoprim-sulpha, nasal mupirocin (Bactroban), or chlorhexidine showers (Hibiclens) 5 times a day
- Bleach baths (1 teaspoon of bleach per gallon of water) x 10 minutes 2 times/wk
- Environmental cleaning (bedclothes, towels, surfaces)
- More controversial is the consideration of treating people around you
- There may be some potential transmission from pets, so pet reservoirs need to be considered for recurrent cases
- Getting CA-MRSA from your environmental transmissions may need to be considered in some cases
MRSA – FAQs:
Does you need to use special techniques when culturing for MRSA?
- No. S. aureus is easy to culture using standard culture tubes
- The best place to culture for carriers is the nose
- Rapid screening tests for MRSA are available and might be considered if there is an urgency to make a diagnosis (see Xpert MRSA distributed by Cepheid)
How can I protect myself from getting MRSA?
The main way to protect against MRSA is by frequent and thorough hand washing.
Is MRSA a reportable disease?
Invasive MRSA infections in hospitals (i.e., positive blood cultures) are reportable. But routine positive cultures from skin and soft tissues are not.
What is the best anti-bacterial soap for MRSA?
Hibiclens - which is available over-the-counter.
Is Purell effective against MRSA?
All alcohol gels and foams like Purell are very effective against MRSA.
Should Bactroban be used to prevent MRSA colonization?
The routine use of Bactroban in the nose has not been shown to prevent colonization.
Should family members of MRSA patients use Hibiclens washes?
Family members of patients who are MRSA carriers should scrub weekly with Hibiclens. They should scrub more often if skin eruptions are present.
How are MRSA patients handled in emergency departments?
When it isn't possible to place a MRSA patient in a separate room, the emergency department should follow the principles of contact precautions (hand hygiene, gloves and gowns for contact, proper disinfection of the area after the patient is discharged) in areas only separated by curtains.*
What about transporting MRSA patients in or to the hospital?
A chief concern is avoiding actions that require any attendant to touch the patient and then possibly contaminate environmental surfaces (door handles, elevator buttons, etc). If a single caretaker is transporting a patient, gown and gloves should be worn until the patient is on the stretcher or wheelchair, and then gloves should be removed and hands washed.
If a patient requires hands-on intervention during transport, the safest approach is to have two individuals transport the patient. One should wear gown and gloves and is responsible for touching the patient, while the other (without gloves) handles the doors and elevator buttons.*
How is MRSA handled on behavioral units?
Most behavioral units are low-risk settings for the transmission of MRSA, so these units are treated like community settings and are considered exempt from hospital isolation guidelines (other than if a patient has an actively draining wound infected or colonized by MRSA). The best way to prevent MRSA transmission on a unit is to educate patients and staff to practice good hand hygiene. Patients should not share potentially contaminated personal items such as towels, soap or razors.*
How are hospital rooms cleaned once a MRSA patient is discharged?
Routine cleaning procedures should be followed for floors and walls. Surfaces visably soiled should be washed first before disinfecting. Frequently touched surfaces (bedrails, bathroom fixtures, etc) need special attention. Curtains should be cleaned when visably soiled. Most EPA-registered hospital disinfectants should adequately inactivate MRSA.*
How long does MRSA stay potentially infective in the environment?
Days to weeks.
* From "Questions About MRSA and Answers From the Experts" by Laura Stokowshi, RN, MS; http//www.medscape.com/viewarticle/546221
MRSA in Healthcare Settings - general information from the CDC website
Information About MRSA for Healthcare Personnel - an excellent resource from the CDC that outlines standard and contact precautions
MRSA Overview - by Joanne Barnett, Central Florida Regional Hospital
What the CDC is Doing About MRSA - from the CDC website
Skin and Soft-Tissue Infections Caused by MRSA - an article from the July 26, 2007 New England Journal of Medicine by Robert S. Daum, MD
Invasive MRSA - a summary of the October 17, 2007 Journal of the American Medical Association (JAMA) article that created widespread media and public interest in MRSA when it reported that MRSA was responsible for 18,650 hospital-related deaths in 2005
Reduce MRSA Infections - an Institute for Healthcare Improvement (IHI) website link
MRSA Patient Information:
MRSA at Home - a patient handout for what to do when family members have MRSA or are MRSA colonizers (from Rancho Los Amigos National Rehabilitation Center)
MRSA at Home (Spanish) - a patient handout in Spanish for what to do when family members have MRSA or are MRSA colonizers (from Rancho Los Amigos National Rehabilitation Center)
Living With MRSA - a patient brochure from the Washington State Department of Health
Hand washing information links:
Wash Hands Often - information on the Seminole County Health Department website
Henry the Hand - general handwashing information for children