MRSA Information

Nationwide, there has been an increase in the number of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections among persons of all ages who previously were considered to be at low risk for this infection.

CA-MRSA infections are predominantly skin and soft tissue infections (SSTIs). The infection is often described as a “spider bite” or appears as reddened areas on the skin.

Proper infection-control practices and appropriate antimicrobial agent management can help limit the emergence and spread of MRSA in the community and health care settings.

Background
Staphylococcus aureus (S. aureus) is a gram-positive bacterium that can be found on the skin and in the nose of approximately 20% – 30% of healthy individuals. It is one of the most common causes for skin and soft tissue infections (SSTIs) in the United States and may also cause invasive disease, including surgical wound infections, bacteremia, pneumonia, necrotizing fasciitis, and toxic shock syndrome. During the past 50 years, treatment of S. aureus infections has become more difficult due to increasing antibiotic resistance.

Methicillin-resistant Staphylococcus aureus bacteria (MRSA) were first recognized in the 1960’s and soon became identified as a source of infection in hospitals and other health care facilities. Beginning in the 1990’s, there has been an increase in MRSA infections among persons who have onset in the community and who do not have health care facility exposure. This pathogen is referred to as community-associated methicillin-resistant Staphylococcus aureus or CA-MRSA. Since there is no nationwide surveillance system for CA-MRSA, the incidence and prevalence in the United States and in New York State are unknown at this time.

Until recently, reports of CA-MRSA outbreaks had been uncommon. However, nationwide and in New York State, outbreaks are being reported with increasing frequency in a variety of community settings, especially where there is close physical contact or close living conditions. Outbreaks have been reported among members of sports teams, children in day care centers, prisoners, injection drug users, men who have sex with men, military personnel living in a dormitory setting, and Native Americans. Frequent skin-to-skin contact between individuals, compromised skin surfaces, sharing of personal items that may become contaminated with wound drainage, contact with contaminated surfaces, and poor personal cleanliness and hygiene are factors that may increase the risk of CA-MRSA transmission.

The New York State Department of Health is advising health care providers about the growing number of CA-MRSA infections in persons of all ages who previously were considered to be at low risk for infection.

The information provided in this advisory is principally based on the report “Strategies for Clinical Management of MRSA in the Community: Summary of an Experts’ Meeting Convened by the Centers for Disease Control and Prevention. March 2006.”

Clinical Characteristics
The spectrum of disease caused by CA-MRSA appears to be similar to that of methicillin-susceptible S. aureus (MSSA). The severity of SSTIs varies from mild superficial infections to deeper soft-tissue abscesses requiring hospitalization for surgical incision and drainage and delivery of intravenous antibiotics. The most common clinical manifestations are:

• Abscesses/boils
• Carbuncles
• Cellulitis
• Folliculitis
• Furunculosis
• Impetigo
• Infected lacerations

Although CA-MRSA usually presents as a SSTI, it can also cause invasive disease. Invasive manifestations occur as complications of preceding SSTIs or viral respiratory tract infections (particularly influenza), as well as invasive disease without recognized preceding infections or risk factors.

Prevention and Control
Intact healthy skin is a natural barrier for infection. Therefore, preexisting cuts, abrasions or other irritated areas can contribute to skin infections, as bacteria find an entry point in the broken skin.

• Enforce strict compliance with hand hygiene.
• Use standard infection control precautions for all patients in outpatient and inpatient healthcare settings. This includes:
• Performing hand hygiene (handwashing or using alcohol-based hand gel) after touching body fluids or contaminated items (whether or not gloves are worn), between patients and when moving from a contaminated body site to a clean site on the same patients.
• Wearing gloves when managing wounds.
• Wearing gowns and eye protection as appropriate for procedures that are likely to generate splashes or sprays of body fluids.
• Using contact precautions for patients with abscesses or draining wounds in which wound drainage cannot be contained.
• Carefully dispose of dressings and other materials that come into contact with pus, nasal discharge, blood, and urine.
• Clean examination room surfaces and patient rooms with an EPA-registered hospital detergent/disinfectant, in accordance with label instructions, or a 1:100 solution of diluted bleach (one tablespoon bleach in 1 quart of water).

Use contact precautions for patients in acute care inpatient settings known or suspected to be infected or colonized with MRSA. This includes:

• Greater spatial separation of patients (through placing infected patients in private rooms or cohorting patients with similar infection status)
• Use gown and gloves for all contact with the patient or their environment
• Use dedicated non-critical patient-care equipment
• Precautions may be modified as appropriate for ambulatory care and other non-acute care inpatient settings based on risk factors for transmission.

Household and Community Setting:
Patient education is a critical component of SSTI case management. To prevent spread of MRSA to others in the community, patients with MRSA, family members, household members, and close contacts should be counseled about the following control recommendations.

• Not pick, scratch, or squeeze pimples or boils.
• Keep wounds covered, particularly those skin infections that produce pus.
• Carefully dispose of soiled dressings/bandages. Heavily soiled bandages or dressings should be placed in a plastic bag before discarding into the trash. If not heavily soiled, they may be placed directly into the trash.
• Refrain from sports or other activities that involve close contact if the patient cannot maintain adequate hygiene and keep wounds covered with clean, dry bandages during activity.
• Wash clothes, towels, sheets, uniforms, etc. and any other soiled items using hot water, laundry detergent and dry on the hottest cycle after each use. Pre-wash or rinse any item that has been contaminated with body fluids.

Patients and their family, household members, and close contacts should:

• Perform frequent handwashing with warm water and soap (preferably not bar soap), especially before and after touching or changing the dressing/bandage. Alcohol-based hand sanitizers may be used instead of soap and water, if hands are not visibly soiled. Whenever possible, dry hands with a paper towel and discard paper towel after use. If using clean disposable gloves to change a dressing/bandage, make sure that hands are washed before putting on and after taking off gloves.
• Maintain a clean environment. Make sure to clean and disinfect surfaces and objects in the immediate environment and shared common areas that may have become contaminated with wound drainage or infected body fluids. Wipe surfaces with a commercial disinfectant or a 1:100 solution of diluted bleach (1 tablespoon bleach in 1 quart water), and allow to air dry.
• Practice good personal hygiene including showering thoroughly each day and as soon as possible after physical activity, direct contact sports, or working out. Make sure to use a clean, dry towel.
• Not share personal care items (i.e., razors, towels, bar soap, and water bottles).
• Not share any topical preparations (i.e., ointments, balm, lotions, deodorants, antibiotic creams).
• Not shave body skin for cosmetic or wound care reasons, as shaving can create micro-abrasions that can permit entry of bacteria.

Resources:
Thompson's Health Information Library

Information on MRSA and CA-MRSA can also be found on the CDC website at:
http://www.cdc.gov/ncidod/dhqp/ar_mrsa_ca_public.html

and at the NYSDOH website at:
http://www.health.state.ny.us/diseases/communicable/staphylococcus_aureus/methicillin_resistant/fact_sheet.htm