MRSA from the Center for Disease control and prevention...

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MRSA - Methicillin Resistant Staphylococcus aureus

Fact Sheet

The Centers for Disease Control and Prevention (CDC) has received

inquiries about infections with antibiotic-resistant Staphylococcus

aureus (including methicillin-resistant S. aureus [MRSA]) among

persons who have no apparent contact with the healthcare system. This

fact sheet addresses some of the most frequently asked questions.

What is Staphylococcus aureus?

Staphylococcus aureus, often referred to simply as " staph, " are

bacteria commonly carried on the skin or in the nose of healthy

people. Occasionally, staph can cause an infection; staph bacteria

are one of the most common causes of skin infections in the United

States. Most of these infections are minor (such as pimples and

boils) and most can be treated without antibiotics (also known as

antimicrobials or antibacterials). However, staph bacteria can also

cause serious infections (such as surgical wound infections and

pneumonia). In the past, most serious staph bacteria infections were

treated with a certain type of antibiotic related to penicillin. Over

the past 50 years, treatment of these infections has become more

difficult because staph bacteria have become resistant to various

antibiotics, including the commonly used penicillin-related

antibiotics (1). These resistant bacteria are called methicillin-

resistant Staphylococcus aureus, or MRSA.

Where are staph and MRSA found?

Staph bacteria and MRSA can be found on the skin and in the nose of

some people without causing illness. Top

What is the difference between colonization and infection?

Colonization occurs when the staph bacteria are present on or in the

body without causing illness. Approximately 25 to 30% of the

population is colonized in the nose with staph bacteria at a given

time (2).

Infection occurs when the staph bacteria cause disease in the person.

People also may be colonized or infected with MRSA, the staph

bacteria that are resistant to many antibiotics. Top

Who gets MRSA?

Staph bacteria can cause different kinds of illness, including skin

infections, bone infections, pneumonia, severe life-threatening

bloodstream infections, and others. Since MRSA is a staph bacterium,

it can cause the same kinds of infection as staph in general;

however, MRSA occurs more commonly among persons in hospitals and

healthcare facilities.

MRSA infection usually develops in hospitalized patients who are

elderly or very sick or who have an open wound (such as a bedsore) or

a tube going into their body (such as a urinary catheter or

intravenous [iV] catheter). MRSA infections acquired in hospitals and

healthcare settings can be severe. In addition, certain factors can

put some patients at higher risk for MRSA including prolonged

hospital stay, receiving broad-spectrum antibiotics, being

hospitalized in an intensive care or burn unit, spending time close

to other patients with MRSA, having recent surgery, or carrying MRSA

in the nose without developing illness (3-6).

MRSA causes illness in persons outside of hospitals and healthcare

facilities as well. Cases of MRSA diseases in the community have been

associated with recent antibiotic use, sharing contaminated items,

having active skin diseases, and living in crowded settings. Clusters

of skin infections caused by MRSA have been described among injecting

drug-users (7,8), aboriginals in Canada (9), New Zealand (10) or

Australia (11,12), Native Americans in the United States (13),

incarcerated persons (14), players of close-contact sports (15,16)

and other populations (17-23). Community-associated MRSA infections

are typically skin infections, but also can cause severe illness as

in the cases of four children who died from community-associated MRSA

(24). Most of the transmission in these settings appeared to be from

people with active MRSA skin infections. Top

How common is staph and MRSA?

Staph bacteria are one of the most common causes of skin infection in

the United States, and are a common cause of pneumonia and

bloodstream infections. Staph and MRSA infections are not routinely

reported to public health authorities, so a precise number is not

known. According to some estimates, as many as 100,000 persons are

hospitalized each year with MRSA infections, although only a small

proportion of these persons have disease onset occurring in the

community. Approximately 25 to 30% of the population is colonized in

the nose with staph bacteria at a given time (2). The numbers who are

colonized with MRSA at any one time is not known. CDC is currently

collaborating with state and local health departments to improve

surveillance for MRSA. Active, population-based surveillance in

selected regions of the United States is ongoing and will help

characterize the scope and risk factors for MRSA in the community. Top

Are staph and MRSA infections treatable?

Yes. Most staph bacteria and MRSA are susceptible to several

antibiotics. Furthermore, most staph skin infections can be treated

without antibiotics by draining the sore. However, if antibiotics are

prescribed, patients should complete the full course and call their

doctors if the infection does not get better. Patients who are only

colonized with staph bacteria or MRSA usually do not need treatment.

Top

How are staph and MRSA spread?

Staph bacteria and MRSA can spread among people having close contact

with infected people. MRSA is almost always spread by direct physical

contact, and not through the air. Spread may also occur through

indirect contact by touching objects (i.e., towels, sheets, wound

dressings, clothes, workout areas, sports equipment) contaminated by

the infected skin of a person with MRSA or staph bacteria. Top

How can I prevent staph or MRSA infections?

Practice good hygiene

1. Keep your hands clean by washing thoroughly with soap and water

2. Keep cuts and abrasions clean and covered with a proper dressing

(e.g., bandage) until healed

3. Avoid contact with other people's wounds or material contaminated

from wounds.

What should I do if I think I have a Staph or MRSA infection?

See your healthcare provider.

What is CDC doing to address MRSA in the community?

CDC is concerned about MRSA in communities and is working with

multiple partners on prevention strategies.

CDC is working with 4 states in a project to define the spectrum of

disease, determine populations affected, and developing studies to

define who is at particular risk for infection

CDC is working with state health departments to assist in the

development of surveillance systems for tracking MRSA in the

community

CDC is using the National Health and Nutritional Evaluation Survey

(NHANES) to estimate the number of individuals in the United States

who carry staph bacteria in their nose

CDC works with laboratories across the country to improve the

detection of MRSA through training personnel and use of appropriate

testing methods

CDC provides technical expertise to hospitals and state and local

health departments on infection control in healthcare settings,

including control of MRSA

CDC laboratories are working to characterize the unique features of

MRSA strains from the community.

Top

References:

1. Lowry FD. Staphylococcus aureus infections. New England Journal of

Medicine. 1998;339:520-32.

2. Kluytmans J, Van Belkum A, Verbrugh H. Nasal carriage of

Staphylococcus aureus: epidemiology, underlying mechanisms, and

associated risks. Clin Microbiol Rev. 1997;10:505-20.

3. Boyce JM. Methicillin-resistant Staphylococcus aureus. Detection,

epidemiology, and control measures. Infect Dis Clinics of North Am.

1989;3:901-13.

4. Herwaldt LA. Control of methicillin-resistant Staphylococcus

aureus in the hospital setting. Am J Medicine. 1999;106:11S-18S;

discussion 48S-52S.

5. Asensio A, Guerrero A, Quereda C, Lizan M, ez-Ferrer M.

Colonization and infection with methicillin-resistant Staphylococcus

aureus: associated factors and eradication. Infec Control Hosp

Epidemiol. 1996;17:20-8.

6. Mulligan ME, Murray-Leisure KA, Ribner BD, et al. Methicillin-

resistant Staphylococcus aureus: a consensus review of the

microbiology, pathogenesis, and epidemiology with implications for

prevention and management. Am J Medicine. 1993;94:313-28.

7. Saravolatz LD, Markowitz N, Arking L, Pohloh D, Fisher E.

Methicillin-resistant Staphylococcus aureus. Epidemiologic

oberservations during a community-acquired outbreak. ls of

Internal Medicine. 1982;96:11-16.

8. CDC. Community-acquired methicillin-resistant Staphylococcus

aureus infections—Michigan. MMWR. 1981;30:185-7.

9. Embil J, Ramotar K, Romance L, et al. Methicillin-resistant

Staphylococcus aureus in tertiary care institutions on the Canadian

prairies 1990-1992. Infection Control and Hospital Epidemiology 1994;

15:646-51.

10. Rings T, Findlay R, Lang S. Ethnicity and methicillin-resistant

S. aureus in South Auckland. New Zealand Medical Journal 1998;

111:151.

11. Maguire GP, Arthur AD, Boustead PJ, Dwyer B, Currie BJ. Emerging

epidemic of community-acquired methicillin-resistant Staphylococcus

aureus infection in the Northern Territory. Medical Journal of

Australia 1996; 1996; 164:721-3.

12. Collignon P, Gosbell I, Vickery A, Nimmo G, Stylianopoulos T,

Gottlieb T. Community-acquired methicillin-resistant Staphylococcus

aureus in Australia. Australian Group on Antimicrobial Resistance.

Lancet 1998; 352:145-6.

13. Groos A, Naimi T, Wolset D, - K, K, Cheek J.

Emergence of community-acquired methicillin-resistant Staphylococcus

aureus in a rural American Indian community (Abstract 1230), 39th

Annual Interscience Conference on Antimicrobial Agents and

Chemotherapy, San Francisco, CA, 1999.

14. Methicillin-resistant Staphylococcus aureus skin or soft tissue

infections in a state prison—Mississippi, 2000. MMWR 2001 Oct. 26. 50

(42); 919-922.

15. Lindenmayer JM, Schoenfeld S, O'Grady R, Carney JK. Methicillin-

resistant Staphylococcus aureus in a high school wrestling team and

the surrounding community. Archives of Internal Medicine 1998;

158:895-9.

16. Stacey AR, Endersby KE, Chan PC, Marples RR. An outbreak of

methicillin- resistant Staphylococcus aureus infection in a rugby

football team. British Journal of Sports Medicine 1998; 332: 153-4.

17. Kallen AJ, Driscoll TJ, Thornton S, Olson PE, Wallace MR.

Increase in community-acquired methicillin-resistant Staphylococcus

aureus at a Naval Medical Center. Infection Control and Hospital

Epidemiology 2000; 21: 223-6

18. Hussain FM, Boyle-Vavra S, Bethel CD, Daum RS. Current trends in

community-acquired methicillin-resistant Staphylococcus aureus at a

tertiary care pediatric facility. Pediatric Infectious Disease

Journal 2000; 19: 1163-6.

19. Feder HM, Jr. Methicillin-resistant Staphylococcus aureus

infections in 2 pediatric outpatients. Archives of Family Medicine

2000; 1163-6.

20. Goetz A, Posey K, Fleming J, et al. Methicillin-resistant

Staphylococcus aureus in the community: a hospital-based study.

Infection Control and Hospital Epidemiology 1999; 20: 689-91.

21. AL, Marcinak JK, Mangat PD, Schreckenberger PC. Community-

acquired and clindamycin-susceptible methicillin-resistant

Staphylococcus aureus in children. Pediatric Infectious Disease

Journal 1999; 18:993-1000.

22. Price MF, McBride ME, Wolf JE, Jr., Prevalence of methicillin-

resistant Staphylococcus aureus in a dermatology outpatient

population. Southern Medical Journal 1998: 91:369-71.

23. Herold BC, Immergluck LC, Maranan MC, et al. Community-acquired

methicillin-resistant Staphylococcus aureus in children with no

identified predisposing risk. JAMA 1998; 279:593-8.

24. From the Centers for Disease Control and Prevention. Four

pediatric deaths from community-acquired methicillin-resistant

Staphylococcus aureus—Minnesota and North Dakota, 1997-1999. JAMA

1999; 282: 1123-5