Methicillin-Resistant Staphylococcus Aureus (MRSA) Presented by: Sandi Henley RN, CIC Texas Department of State Health Services, Region 7

Staphylococcus aureus Staphylococcus aureus, often referred to simply as "staph," are bacteria commonly carried on the skin or in the nose of healthy people.

Staph and More Staph Staphylococcus aureus: The staph bacteria are one of the most common causes of skin infections in the United States Most of these skin infections are minor (such as pimples and boils) and can be treated without antibiotics (also known as antimicrobials or antibacterials). Laypeople and health care professionals alike recognize Staphylococcus aureus as an important cause of disease and understand that antibiotic-resistant strains pose a threat to the community. Before the availability of antibiotics, invasive staphylococcal disease was often fatal, and the introduction of penicillin in the 1940s dramatically improved survival. Although penicillinase-producing strains soon emerged, methicillin and other penicillinase-stable B-lactam agents filled the breach.

Staphylococcus aureus However, staph bacteria also can cause serious infections (such as surgical wound infections, bloodstream infections, and pneumonia).

Staphylococcus aureus Approximately 25% to 30% of the population is colonized (when bacteria are present, but not causing an infection) in the nose with staph bacteria.

Staphylococcus aureus “THE SUPER BUG” Methicillin-resistant Staphylococcus aureus (MRSA) HA-MRSA – refers to Hospital (or Healthcare) Acquired Methicillin Resistant Staphylococcus aureus which occurs in a hospital or other healthcare related institution or in individuals receiving healthcare (ie dialysis) on an ongoing basis Increasingly important cause of healthcare-associated infections since 1970s CA-MRSA – refers to Community Acquired Methicillin Resistant Staphylococcus aureus which occurs in individuals that are normally healthy and not receiving healthcare on an ongoing basis for chronic conditions In 1990s, emerged as cause of infection in the community However, methicillin-resistant strains of S. aureus (MRSA), which are resistant to the entire class of -lactam agents, were identified almost immediately and are now found in hospitals worldwide. Despite the growing prevalence of MRSA in hospitals, these strains have been uncommon in the community. The absence of antibiotic selective pressure favoring their survival, detriment to fitness, and attenuated virulence were thought to make the resistant organisms unable to compete in the community.

MRSA While 25% to 30% of the population is colonized with staph approximately 1% is colonized with MRSA. Colonization is when an individual has the bacteria on their skin or mucus membranes but does have any disease, infection, from the bacteria.

Not a new “SUPERBUG” As shown on previous slides – been around since the 1970s Community acquired MRSA became more prevalent in the 1990’s

The following is an excerpt from TIME Magazine - Time - Sep 12, 1960 “Too sick even to cry, the tiny, four-week-old infant lay limply on its bed in a British hospital Tests of blood and pus samples, drawn from an inflamed abscess on the child's right hip, produced a chilling diagnosis: Staphylococcus aureus, of the dreaded "hospital type," which is resistant to penicillin and most antibiotics. With little hope of success, physicians administered massive doses of penicillin and streptomycin. Neither worked, and the child hovered near death.” This was an example of staph that was resistant to penicillin – a very dreaded event at the time. As an aside, the child did survive after being given a new antibiotic – which was a ß-lactam type still being tested. This is an example of a case that occurred in the 60’s, after Staph began exhibiting resistance to the antibiotics in use at that time - penicillin and streptomycin. This infant was given an experimental drug – related to Methicillin and did survive. Hope

Why are we seeing MRSA After the event of pencillinase producing Staph aureus – or a resistant form of Staph- in the 50 and 60’s, physicians begin using the ß-lactam antibiotics. Methicillin is a ß-lactam antibiotic It didn’t take many years for resistance to these ß-lactam antibiotics to emerge. This was the beginning of MRSA.

Time required for prevalence rates of resistance to reach 25% in hospitals Drug Year Introduced Years to Report Resistance Years until 25% Rate In hospitals 25% rate in community Penicillin 1941 1-2 6 15-20 Vancomycin 1956 40 ? Methicillin 1961 <1 25-30 45-50 (projected) Traditionally, beta-lactam antibiotics work by inhibiting penicillin-binding proteins. Methicillin was originally designed to resist beta-lactamase and remain effective against S aureus. As early as 1945, strains of S aureus acquired a secreted beta-lactamase that degrades penicillin, and this progression rendered methicillin ineffective against this bacteria Emerging Infectious Diseases, Vol 7, No 2, Mar-Apr 2001 The Changing Epidemiology of Staphylococcus aureus? Henry F. Chambers

December 16, 1993 Community-Acquired Methicillin-Resistant Staphylococcus aureus Infection To the Editor: We report a community-acquired methicillin-resistant Staphylococcus aureus infection in a 65-year-old woman who did not use intravenous drugs and was not a nursing home resident. The patient was hospitalized with endocarditis due to methicillin-resistant S. aureus. Neither she nor her husband had been hospitalized for the past 15 years. They had not visited a nursing home. No family members worked in a health care facility, and none used intravenous drugs. She became deaf, quadriplegic, and aphasic as a result of the infection and its treatment. Cells for culture were obtained from the hands, nose, and throats of family members, including the husband, two daughters, and two grandchildren. Methicillin-resistant S. aureus was isolated from the nose of a five-year-old grandson, who lived one block away. Six months later methicillin-resistant S. aureus was again isolated from the grandson. It was not found 18 months later. …………………………………………………………………………………………………………………………………………………….……………………………… We do not know the extent of colonization with methicillin-resistant S. aureus in the community. We hope that this case is an isolated one.

Who gets staph or MRSA infections? Staph infections, including MRSA, occur most frequently among persons in hospitals and healthcare facilities (such as nursing homes and dialysis centers) who have weakened immune systems. These healthcare-associated staph infections include surgical wound infections, urinary tract infections, bloodstream infections, and pneumonia.

What is community-associated MRSA (CA-MRSA)? Staph and MRSA can also cause illness in persons outside of hospitals and healthcare facilities. MRSA infections that are acquired by persons who have not been recently (within the past year) hospitalized or had a medical procedure (such as dialysis, surgery, catheters) are known as CA-MRSA infections. Staph or MRSA infections in the community are usually manifested as skin infections, such as pimples and boils, and occur in otherwise healthy people.

Contaminated Surfaces Risk Factors Defense Offense Frequent Contact Crowding Antimicrobial Use Compromised Skin Contaminated Surfaces and Shared Items Cleanliness

CA-MRSA Infections are Mainly Skin Infections Disease Syndrome (%) Skin/soft tissue 1,266 (77%) Wound (Traumatic) 157 (10%) Urinary Tract Infection 64 (4%) Sinusitis 61 (4%) Bacteremia 43 (3%) Pneumonia 31 (2%) Fridkin et al NEJM 2005;352:1436-44

Most Invasive MRSA Infections Are Healthcare-Associated 14% 86% As discussed most of the Invasive infections are those that are healthcare associated Klevens et al JAMA 2007;298:1763-71

Overall Incidence (all ages): Infections: 4.6 per 100,000 Incidence of Invasive CA-MRSA Infections and Deaths by Age Active Bacterial Core surveillance (ABCS), 2005 Incidence per 100,000 persons Overall Incidence (all ages): Infections: 4.6 per 100,000 Deaths: 0.5 per 100,000 This graph illustrates the incidence of INVASIVE Community Acquired MRSA by age of the patient. You will notice the blue bars which are the deaths are mostly in patients that are older. Klevens et al JAMA 2007;298:1763-71

Types of CA-MRSA Infections Furuncles Impetigo Scalded Skin Syndrome Necrotizing soft tissue infections Septic arthritis/osteomyelitis Pneumonia Endocarditis Toxic Shock Syndrome What has really exploded throughout the United States in the last 2 or 3 years has been the community-acquired, or CA-MRSA, infections. A number of different syndromes have been described: furuncles, impetigo, scalded skin syndrome, pneumonia, endocarditis, and toxic shock syndrome, as well as septic arthritis and osteomyelitis. Prosthetic joint infections are an increasingly difficult management problem due to MRSA infections; finally, necrotizing soft tissue infections have been associated with CA-MRSA.

HA-MRSA /CA-MRSA HA-MRSA CA-MRSA Age – mean 68 Underlying disease 76% Skin and Soft tissue 37% Respiratory tract 22% CA-MRSA Age – mean 23 Underlying disease 15% Skin and Soft tissue 75% Respiratory tract 6% In addition, there are some striking differences between clinical factors. The hospital-acquired strains were associated with older age, underlying disease. Skin and soft tissue infections accounted for about 37% of all-comers; respiratory infections, particularly ventilator-associated pneumonias, were more common than in the community-acquired strains. In contrast, the skin and soft tissue infections were predominant in the community-acquired infections. Underlying disease was fairly uncommon, and the mean age was 23 years Naimi TS et al. JAMA, 2003, 290:2976-2984

Community-Associated MRSA: CDC Population-Based Surveillance Definition MRSA culture in outpatient setting or 1st 48 hours of hospitalization AND patient lacks risk factors for healthcare-associated MRSA: Hospitalization Surgery Long-term care Dialysis Indwelling devices History of MRSA This is the definition developed by CDC to help differentiate those patients with CA-MRSA entering a hospital or seen in an outpatient basis from those with the HA-MRSA.

Outbreaks of MRSA in the Community Often first detected as clusters of abscesses or “spider bites” Various settings Sports participants Inmates in correctional facilities Military recruits Daycare attendees Native Americans / Alaskan Natives Men who have sex with men Tattoo recipients Individuals living in Long Term Shelters

Clinical Considerations - Evaluation MRSA should also be considered in differential diagnosis of severe disease compatible with S. aureus infection: Osteomyelitis Empyema Necrotizing pneumonia Septic arthritis Endocarditis Sepsis syndrome Necrotizing fasciitis Purpura fulminans Recommendations to physicians include considering Staph, not only MRSA, for patients with these infections.

Management of Skin Infections in the Era of CA-MRSA I&D should be routine for purulent skin lesions Obtain material for culture No data to suggest molecular typing or toxin-testing should guide management Empiric antimicrobial therapy may be needed Alternative agents have +’s and –’s: More data needed to identify optimal strategies Use local data for treatment Patient education is critical! Maintain adequate follow-up Today, physicians are also being advised to following these strategies when caring for patients with a skin infection. Many times the physician may feel that lancing or an I&D could be sufficient to treat these infections; but may also want to start a person with a skin infection on antimicrobial therapy. This is a clinical decision that will be made by the physician. Methicillin Resistant Staphylococcus aureus(MRSA) in the Community: Epidemiology and Management Rachel Gorwitz, MD, MPH; Division of Healthcare Quality Promotion; Centers for Disease Control and Prevention

Recommended Measures to Limit the Spread of Community-Associated MRSA Isolates.* Cover draining wounds with clean bandages. Wash hands, especially after contact with a contaminated wound. Launder clothing after contact with a contaminated area on the skin. Bathe regularly with use of soap. Avoid sharing items (e.g., towels, bedding, clothing, razors, or athletic equipment) that may become contaminated by contact with wounds or skin flora. Clean sports equipment with agents that are effective against staphylococci (e.g., a detergent or disinfectant registered by the Environmental Protection Agency, such as quaternary ammonium compounds or a solution of dilute bleach). *Gorwitz RJ, Jernigan DB, Powers JH, Jernigan JA. 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

Management of Severe / Invasive Infections Vancomycin remains a 1st-line therapy for severe infections possibly caused by MRSA Other IV agents may be appropriate Consult an infectious disease specialist. Final therapy decisions should be based on results of culture and susceptibility testing Severe community-acquired pneumonia: Vancomycin or linezolid if MRSA is a consideration* *IDSA/ATS Guidelines for treatment of CAP in adults: Mandell et al. CID 2007;44:S27-72

MRSA Symptoms Dependant on the part of the body affected. Remember most CA-MRSA are infection soft the skin or other soft tissue. Look for areas that are: Swollen Red Painful Pus-filled Many people mistake a staph skin infection for a spider bite

OTHER TYPES OF CA-MRSA INFECTIONS Staph that infects the lungs and causes pneumonia can lead to: Shortness of breath Fever Chills Not limited to CA-MRSA – all staph aureus can cause pneumonia Staph Pneumonia represents a relatively rare phenomenon.

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Appropriate Antibiotic Use

This video was produced in partnership with Kaiser Permanente Talking with Patients About Antibiotic Use: An Interaction Model This video displays a conversation between a healthcare provider and a patient. the physician explains to the patient the difference between bacteria and virus and why colds are not treated with antibiotics. Click here to start Video

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Should Schools Close? This decision will be made by school officials in consultation with local and/or state public health officials However, in most cases, it is not necessary because of a MRSA infection in a student

Should the school notify parents for each MRSA infection? Usually, it should not be necessary to inform the entire school community about a single MRSA infection HOWEVER – the school should be notified of a student’s MRSA infection so that appropriate steps can be taken to help prevent the spread of germs. Remember MRSA can be prevented by SIMPLE MEASURES such as hand hygiene and covering infections

SUMMARY New strains of MRSA have emerged in the community, with implications for management of skin infections and other staphylococcal infections. Incision and drainage remains a primary therapy for purulent skin infections. Oral treatment options are available for patients with skin infections that require ancillary antibiotic therapy. Patient education on proper wound care is a critical component of case management for patients with skin infections. Strategies focusing on increased awareness, early detection and appropriate management, enhanced hygiene, and maintenance of a clean environment have been successful in controlling clusters / outbreaks of infection.

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