What you need to know about MRSA

What you need to know about MRSA

Get Schooled looks at MRSA.
October 29, 2007

Methicillin-resistant staphylococcus aureus, or MRSA, infections have been featured in several news stories lately, including reports of cases in local schools. As of Friday, 12 confirmed cases had been reported in schools, most of them linked to athletes. Statewide, the number is more than 40. Here is some information about MRSA and how to avoid getting or spreading infections.

Q: What is Methicillin-resistant staphylococcus aureus?

A: Staphylococcus aureus, called staph, is a common type of bacteria found on the skin and in the nose and lungs of healthy people. It acts as a hitchhiker most of the time, causing no harm, but if a person gets a cut or other wound, or an illness that weakens the lining of the lungs, an infection can occur. Most staph infections respond to penicillin and similar antibiotics. MRSA is resistant to penicillin and related antibiotics, so other drugs must be used to treat it.

Q: How do you get an MRSA infection?

A: Staph bacteria, including MRSA, are spread by close contact with infected people or the things they touch. The bacteria are not spread through the air.

Q: How many MRSA infection cases have been reported by local schools?

A: As of Oct. 26, six medically confirmed MRSA infections had been reported by local schools. Only one person was hospitalized. All those with infections are receiving, or have completed, treatment.

Q: What are local schools doing about it?

A: They are working with local health officials to educate teachers, coaches, athletic directors and students about staph infections. School custodians are cleaning locker rooms, weight rooms and other common athletic areas and shared athletic equipment, with hospital-grade disinfectants. Schools also are encouraging students to follow simple prevention measures.

Q: What can I do to prevent an infection?

A: Health officials say the best way to prevent infection is to wash your hands frequently; avoid sharing personal items such as towels, razors, sports equipment and make-up; and cover wounds. If a wound becomes red, painful or slow to heal, see a physician.

Q: Where can I get more information?

A: If you have questions about what your school is doing, or want to report a medically confirmed case of MRSA infection, contact your school administrator or nurse. For more information about MRSA, visit the Virginia Department of Health Web site, which contains information about the bacteria and infection prevention measures: Sources: Virginia Department of Health; Centers for Disease Control and Prevention. Get Schooled! Have an education question that you'd like us to explore? Send it to getschooled@dailypress.com or call 757-247-4668.

Newport News, Va., Daily Press

Community-associated MRSA (CA-MRSA): an emerging pathogen in infective endocarditis.

Community-associated MRSA (CA-MRSA): an emerging pathogen in infective endocarditis.
B. Cherie Millar1, Bernard D. Prendergast2 and John E. Moore1,*
1 Northern Ireland Public Health Laboratory, Department of Bacteriology, Belfast City Hospital, Lisburn Road, Belfast BT9 7AD, Northern Ireland, UK 2 Department of Cardiology, John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK

* Corresponding author. Tel: +44-28-9026-3554; Fax: +44-28-9026-3991; E-mail: jemoore@niphl.dnet.co.uk

Over the last decade, a novel methicillin-resistant Staphylococcus aureus (MRSA) has emerged, primarily associated with healthy individuals within the community. This organism is distinct from healthcare-associated MRSA (HA-MRSA) in terms of epidemiology, microbiology and clinical manifestation and as such has been defined as community-associated MRSA (CA-MRSA). Given that S. aureus is a major aetiological agent of infective endocarditis (IE), particularly associated with the iv drug user population, reports of IE attributed to CA-MRSA are now emerging in the literature. The aims of this article are to (i) define and contrast CA-MRSA with HA-MRSA; (ii) review the published cases of CA-MRSA IE to date; and (iii) evaluate the current international recommendations for antibiotic prophylaxis and treatment regimens for IE in relation to CA-MRSA.

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has now emerged on five continents (Europe, Asia, Australia, North America and South America)1,2 over the last decade, but particularly in the USA, where there have been several seminal publications on this organism.3–5 CA-MRSA has distinctly different microbiological, epidemiological and molecular characteristics from those of healthcare-associated MRSA (HA-MRSA), and based on these differences (Table 1), new definitions have been published in an attempt to differentiate between these two organisms.6

CA-MRSA is usually associated with young healthy individuals in the community, who have no risk factors for acquisition of HA-MRSA. Several reports have documented CA-MRSA infections affecting individuals in prisons, military personnel, athletic populations, male homosexuals and ethnic populations (native Alaskans and American Indians, Hawaiian islanders). CA-MRSA is primarily associated with skin and soft tissue infections (abscesses, cellulitis and furunculosis); however, there have been severe cases of CA-MRSA infection associated with septic shock, bacteraemia and necrotizing pneumonia. For a comprehensive review on CA-MRSA, see Zetola et al.7 It remains unclear as to whether CA-MRSA evolved historically from the acquisition of SCCmec elements conferring methicillin resistance, through an altered penicillin-binding protein (PBP2') in the bacterial cell wall, within methicillin-susceptible S. aureus (MSSA) in the community or if CA-MRSA was originally derived from HA-MRSA.

More recently, infective endocarditis (IE) due to the involvement of CA-MRSA has been described. In order to identify cases of CA-MRSA IE, a thorough interrogation of the PubMed Search Engine was carried out by using several key words including ‘endocarditis’, ‘MRSA’ and ‘community’, seeking articles that were in print by July 2007 and which described clinical cases of IE associated with CA-MRSA. The determination of CA-MRSA was made by the original authors of the cases discussed, to include epidemiological, microbiological and molecular characteristics of each case, and a summary of these 23 published cases is detailed in Table 2. To date, reports of CA-MRSA IE have been limited to highly industrialized and developed regions including North America, Europe, Asia and Australia, though the majority (68%) of cases have originated in the USA. As yet, there have been no reports from developing nations, although this may reflect reporting bias and/or the absence of high-quality microbiological characterization. From the known epidemiological information recorded, CA-MRSA IE has been primarily acquired within the community and associated with a young, healthy population with no known risk factors for the acquisition of IE. It should be noted, however, that a large proportion of cases have a documented history of some form of skin lesion, including furunculosis, cellulitis and/or iv drug abuse. All cases reported to date have been associated with native valves, predominately the tricuspid valve (Table 3).

Where there has been sufficient epidemiological information provided, a comparison of clinical characteristics and outcome of these cases of CA-MRSA IE (Table 3) has been made with collated cases of native valve MSSA IE and native valve MRSA IE, taken from the merged database of the International Collaboration on Endocarditis (ICE), as previously published.18 This comparison shows a close correlation of CA-MRSA IE to MSSA IE, particularly in terms of age, acquisition in the community, vegetation location and embolic complications. Mortality associated with CA-MRSA IE has been shown, to date from the limited numbers of cases reported, to be markedly lower at 13%, in comparison with either HA-MRSA IE or MSSA IE, which is 37.2% and 23.2%, respectively (Table 3), whereas associated mortality due to Propionibacterium and Candida endocarditis has been 13.3% and 37%, respectively, as reported previously by ICE.19,20

Although CA-MRSA IE resembles MSSA IE more closely than MRSA IE, the antibiotic management of CA-MRSA IE requires a similar approach to treatment as MRSA IE, as a result of the resistance of CA-MRSA to ß-lactam agents. Although CA-MRSA tends to be more susceptible to antibiotic agents than HA-MRSA, treatment should follow current international guidelines as described by the British Society for Antimicrobial Chemotherapy (BSAC),21 the European Society for Cardiology (ESC)22 and the American Heart Association (AHA)23 (Table 4). In all the CA-MRSA IE cases described, patients received vancomycin, frequently combined with a second agent (rifampicin, gentamicin, linezolid, co-trimoxazole, daptomycin and clindamycin). In the majority of cases, the patients were treated solely by antimicrobial therapy; however, surgical intervention was performed in five cases, four of which had valve replacement and one case had a vegectomy. The mortality rate of 13% was markedly lower than that in MSSA IE or HA-MRSA IE (23% and 37%, respectively) (Table 3). As CA-MRSA is relatively more susceptible to treatment than HA-MRSA, this may eventually lead to a new set of specific treatment guidelines for CA-MRSA, as its antibiotic susceptibility may allow several novel combinations of agents to be used. However, it is difficult to evaluate such novel approaches, until clinical experience evolves. At present, we are not aware of any CA-MRSA that is resistant to vancomycin and, therefore, we do not believe that CA-MRSA should be regarded as being different in terms of the BSAC, AHA and ESC antibiotic guidelines. However, this is a situation that requires careful monitoring, as antibiotic susceptibility patterns may begin to evolve, if this organism becomes more endemic in healthcare settings, as is the case in the USA, with the associated diversity and quantity of anti-infectives used in the hospital setting.

Given that CA-MRSA is an organism that resides on skin and outer epithelial surfaces, this location may play a significant role in the potential introduction to the host. Consequently, it is important to give careful consideration to this ecological niche in relation to antibiotic prophylaxis. When the published cases are examined, none of the patients with CA-MRSA IE had documented classical risk factors for the acquisition of IE, e.g. heart murmur, structural heart disease or prior rheumatic fever. These data suggest that a new ‘at risk’ group may be emerging, namely, patients with some form of CA-MRSA skin lesion coupled with iv drug abuse or diabetes mellitus. At present, it is difficult to draw definitive conclusions, not least as the overall role of antibiotic prophylaxis for IE is currently undergoing major reappraisal. However, with increasing reports, careful consideration should be given to this potential new ‘at risk’ group.

Cardiologists and microbiologists need to be aware of the growing significance of this organism and its potential to cause IE. CA-MRSA, although an organism with its origins in the community, has already emerged in nosocomial transmission within healthcare settings, particularly neonatal intensive care units, where it has been involved in several types of infections. Although a very rare event to date, the risk remains relating to the potential for nosocomial IE, from CA-MRSA acquired in the community, but spreading in the healthcare setting. Unlike conventional IE, CA-MRSA has a worrying trait, appearing to cause IE in otherwise healthy and young patients akin to its more common presentation with skin lesions. The combination of CA-MRSA in skin lesions and skin trauma through injection (iv drug abuse and diabetes mellitus) may represent a new susceptible population for the acquisition of CA-MRSA IE. We therefore would encourage continued reporting and examination of the epidemiology of IE because of this causal organism in an attempt to define the optimal antibiotic treatment regimens, as well as the potential role (if any) for the prevention of this infection.

Oxford Journals

Using marker pens on patients: a potential source of cross infection with MRSA.

Using marker pens on patients: a potential source of cross infection with MRSA.
Ann R Coll Surg Engl. 2007 Oct

Tadiparthi S, Shokrollahi K, Juma A, Croall J.
Department of Plastic and Reconstructive Surgery, Countess of Chester Hospital, Chester, UK. tadiparthi@hotmail.co.uk

Keywords: MARKER PENS; MRSA; SURGICAL MARKING; CORRECT SITE SURGERY; NOSOCOMIAL INFECTION; PRE-OPERATIVE MARKING

INTRODUCTION: Marker pens are widely used in surgery but pre-operative marking of patients may be a cause of bacterial cross-infection.

PATIENTS AND METHODS: Two experiments were performed to assess whether marking pens can be cause of cross-infection: (i) 26 indelible marker pens were collected from surgical wards for analysis; and (ii) 'fresh' as well as 'dry' (artificially dried by removing cap and exposing tip for 2 h) new permanent marker pens, and whiteboard marker pens were inoculated by dipping the tips into various concentrations of methicillin-resistant Staphylococcus aureus (MRSA). Each pen was inoculated onto 2 blood agar plates at 0 (immediately after inoculation) to 30 min at various intervals, 4 h and 24 h. The plates were incubated for 18 h at 35 degrees C in an incubator.

RESULTS: Of 26 pens collected from the wards, 2 cultured Micrococci spp. (skin commensals). The constituents of new 'fresh' pen tips rapidly kill MRSA - in all cases by 4 h, but usually within minutes. At high inoculum concentrations, MRSA is not killed immediately. Dry marker pens harbour MRSA for at least 30 min and probably longer.

CONCLUSIONS: Marker pens can act as fomites for nosocomial infection. The ethanol-based ink in permanent marker pens has a bactericidal action against MRSA that starts within seconds, and they are likely to be safe to use with a gap of at least 2 min between patients. Usually, harmless skin commensals are not pathogenic except in immunocompromised patients. Old or dried-out marker pens can harbour pathogens and should be discarded before attempted use on patients. We recommend disposable markers for the immunocompromised and patients with a known positive MRSA status.

Ingenta

State must push for MRSA tests

State must push for MRSA tests

By BETSY McCAUGHEY First published: Thursday, October 25, 2007

The recent Journal of the American Medical Association report that more people in the United States are killed by super-bug staph infections than by HIV should spur state lawmakers into action.

Some 18,000 people die from methicillin-resistant Staphylococcus aureus (MRSA) infections each year, according to the report, and 85 percent of victims pick up the germ in hospitals and other health care facilities.

The death toll is significantly larger than previous estimates. Why?

Because it is based on patients' actual laboratory results rather than on what hospitals tell families or report on the death certificate. Many families that lose their loved one to a hospital infection are horrified to find that the death certificate says something else.

At last, MRSA victims are being counted. But exposing the size of the problem isn't enough. Other states are requiring hospitals to move aggressively against these infections. Hospitals in New York are doing too little.

In August, Illinois Gov. Rod Blagojevich signed a law requiring hospital patients to be routinely tested for MRSA. New Jersey and Pennsylvania passed similar legislation last summer.

The MRSA test is noninvasive, a simple skin or nasal swab. In 2003, a committee of the Society for Healthcare Epidemiology of America urged hospitals to initiate screening programs.

Hospitals such as Brigham & Women's in Boston, Johns Hopkins in Baltimore, Evanston Northwestern in Illinois, University of Pittsburgh in Pennsylvania, and Veterans' Administration medical centers are leading the way. But most hospitals in New York have been slow to act, and New York lawmakers have been even slower.

Why is MRSA testing needed?

Patients who unknowingly carry MRSA shed it in tiny particles on bed rails, wheelchairs, blood pressure cuffs, stethoscopes and the floor under their beds. They don't realize they have it, because the germ doesn't make you sick unless it gets inside your body through a catheter, a surgical incision or other open wound, or a ventilator.

MRSA can live for many hours on surfaces and fabrics. Doctors and other caregivers who lean over an MRSA-positive patient to change a dressing or do an examination often pick up the germ on their lab coats and transmit it to their next patient.

When a nurse wraps an inflatable blood pressure cuff around your bare arm, the cuff frequently contains live bacteria, including MRSA, left behind by a previous patient. Being in a room previously occupied by a patient unknowingly carrying MRSA puts you at risk.

Holland, Denmark and Finland once faced soaring rates of MRSA hospital infections, and nearly eradicated them. How?

By identifying patients carrying MRSA and taking precautions to prevent the germ from spreading to other patients on hands, equipment and clothing.

These precautions work in America, too. The University of Pittsburgh-Presbyterian Medical Center reduced MRSA infections by 90 percent, using screening and the same follow-up precautions.

Can hospitals afford to screen for MRSA?

They can't afford not to. When a patient develops an infection and has to spend many additional weeks hospitalized, the hospital isn't paid for most of that additional care.

"Virtually all published analyses" show that screening and follow-up precautions cost far less than treating hospital infections, according to the medical journal Lancet (September 2006). Most importantly, screening saves lives.

Screening also protects patients who have MRSA, because once you know that you carry it on your skin, added steps can be taken before and during your surgery to prevent the bacteria from getting inside your body.

New York lawmakers should enact a screening law. In addition, they should insist that all hospitals are inspected for cleanliness. MRSA spreads from patient to patient on unclean hands and inadequately cleaned equipment. Restaurants are inspected yearly for cleanliness, but not hospitals. Not even operating rooms. That's absurd.

Finally, there's the truth gap that the JAMA report exposed. Many more patients have been dying from MRSA than hospitals let on. New York already has enacted a hospital infection reporting law, but its value will depend on truthfulness. When hospitals fail to deal honestly with families about what killed their loved one, there ought to be a penalty.

Betsy McCaughey, a former New York lieutenant governor, is the founder and chairwoman of the nonprofit Committee to Reduce Infection Deaths

Times Union

French Clay Can Kill MRSA And 'Flesh-Eating' Bacteria

French Clay Can Kill MRSA And 'Flesh-Eating' Bacteria

ScienceDaily (Oct. 26, 2007) — French clay that kills several kinds of disease-causing bacteria is at the forefront of new research into age-old, nearly forgotten, but surprisingly potent cures. Among the malevolent bacteria that a French clay has been shown to fight is a "flesh-eating" bug (M. ulcerans) on the rise in Africa and the germ called MRSA, which was blamed for the recent deaths of two children in Virginia and Mississippi.

"There are very compelling reports of clay treating infections, but that's anecdotal evidence, not science," said Lynda Williams, an associate research professor in the School of Earth and Space Exploration at Arizona State University, Tempe. Williams is coordinating three teams of U.S. researchers (at ASU, USGS, and SUNY-Buffalo) studying healing clays under a two-year, $440,000 grant from the National Institutes of Health-National Center for Complementary and Alternative Medicine. Her ASU colleague Shelley Haydel is lending her expertise in clinical medicine to perform the microbiological research.

For thousands of years, people have used clay to heal wounds, soothe indigestion, and kill intestinal worms. Though the practice has declined in modern times, the recent rise of drug-resistant germs has scientists looking more closely at these ancient remedies to learn exactly what they can do and how they do it.

"We're beginning to generate the first scientific evidence of why some minerals might kill bacterial organisms and others might not," said Williams.

In laboratory tests at ASU's Biodesign Institute, co-PI Haydel, an assistant professor in the School of Life Sciences, showed that one clay killed bacteria responsible for many human illnesses, including: Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), penicillin-resistant S. aureus (PRSA), and pathogenic Escherichia coli (E. coli).

It also killed Mycobacterium ulcerans, a germ related to leprosy and tuberculosis that causes the flesh-eating disease Buruli ulcer. This effect was first described in 2002, by Line Brunet de Courssou, a French humanitarian working in the Ivory Coast, Africa, who cured Buruli ulcers with daily applications of French clay she knew from childhood. Currently, advanced cases of Buruli ulcer can only be cured by surgical excision or amputation.

The new medicinal clay research will be presented on Monday, 29 October 2007, at the Geological Society of America Annual Meeting in Denver.

In the same session there will be a related presentation describing the work 100 years ago of Julius Stumpf, a German physician and scientist who used white clay from Germany to treat a deadly form of Asian cholera; diphtheria; gangrene; ulcers of the tibia (a bone between the knee and foot); and the skin disease eczema.

Adapted from materials provided by Geological Society of America.

Science Daily

MRSA: Bacterium poses small risk if caught early

MRSA: Bacterium poses small risk if caught early

BY CHRIS A. COUROGEN / Of The Patriot-News, 10/24/07 10:20 PM EDTUPDATED: 10/25/07 10:14 AM EDT

MRSA — “superbug” or too much hype?

The drug-resistant bacterial infection has been dominating the headlines and feeding anxiety in schools, gyms and health care facilities across the nation.

The buzz began last week when a Journal of the American Medical Association study announced methicillin-resistant staphylococcus aureus — a staph infection — was responsible for more deaths each year in the U.S. than the AIDS virus.

Schools across the country began ordering disinfectant after last week’s death of a 17-year-old Virginia student.

The bacteria made news in the midstate this week when a Harrisburg School District seventh-grader was sent home after officials found out he had been diagnosed with MRSA. The boy was being treated with medication and a doctor’s note cleared him to return to class. District officials still kept him out on Wednesday after scrubbing down the Lincoln Elementary School Tuesday night.

While health experts stress that MRSA is serious, the vast majority of deaths caused by the staph infection are among people who contracted it in health care facilities.

“It is appropriate for the public to be concerned, but not fearful,” said Dr. Gregory M. Caputo, who heads the infection control team at Penn State Milton S. Hershey Medical Center.

Stacy Friedman, a spokeswoman for the state Health Department, agreed.

“What we want to stress is, it’s not only very preventable, it is very treatable,” said Friedman.

Closing down schools for cleaning and disinfecting “is really not necessary,” she said.

The district took cautionary steps that went beyond what health authorities advised.

“There has been so much in the press about MRSA. We wanted to be sure we were being as careful as we can be,” said Julie Botel, Harrisburg School District deputy superintendent.

“The truth of the matter is, the Centers for Disease Control and the PA Department of Health both told us it was not necessary to send him home,’’ Botel said. “In fact, they told us it was not necessary to clean the building.”

Harrisburg is not the only local school dealing with MRSA.

In Lancaster County, an elementary school student returned to class Monday in the Hempfield School District after being treated for MRSA. A student in Franklin County’s Greencastle-Antrim School District last week was diagnosed with the bacteria. While school officials there wouldn’t release any other information, they said all the district’s buildings would be cleaned.

And the Lebanon Daily News reports a Northern Lebanon High School student had surgery for an advanced case of the disease in September. The paper said the district’s superintendant was unaware of the case. Calls to the school district for comment were not returned.

Outside of health care facilities, MRSA is typically transmitted by direct skin-to-skin contact, according to the CDC.

Practicing good hygiene — washing with soap and water or an alcohol-based sanitizer, showering after exercise workouts, covering open wounds and not sharing personal items such as razors and towels — helps prevent infection.

Normal proper cleaning procedures are sufficient to combat MRSA, according to the CDC. Students and staff who become infected need not be isolated or sent home, as long as they are being treated and any wounds are properly covered.

“Concern is the appropriate response. Fear and panic are not the appropriate response,” said Caputo of the CDC. “It is not among the most common of fatal conditions or the most common community acquired conditions, such as flu or pneumonia. That puts it into perspective.”

The death rate from getting MRSA outside a health care facility is 0.5 per 100,000, according to the medical association study.

The key is to seek treatment early, before the infection spreads to the bloodstream, Caputo said. Although resistant to penicillin-related drugs, MRSA can be treated effectively and cured with other antibiotics.

Infections caused by staph bacteria, including MRSA, are manifested as skin infections that might look like spider bites, boils or pimples. Often they are sore to the touch, red and swollen, with pus or other drainage, according to the CDC.

There is no accurate measure of MRSA cases in the state. Health care institutions are not required to report it. Hospitals and long term care facilities will begin reporting MRSA infections acquired in their facilities next year under a recently passed Prescription for Pa., but that law does not mandate reporting of community acquired MRSA cases.

Both Friedman and Caputo welcomed the heightened awareness of MRSA that has come from the new study.

“It is a good opportunity to stress the importance of good personal hygiene,” Friedman said.

Very true, Botel said.

“There really is a silver lining going into the flu season,” Botel said. “It is good that our kids’ awareness is heightened about the importance of hand washing and good hygiene.”
CHRIS A. COUROGEN: 717-255-8112 or ccourogen@patriot-news.com

THE SYMPTOMS

The drug-resistant germ methicillin-resistant staphylococcus aureus, or MRSA, sometimes first appears on the skin as a red, swollen pimple or boil that might be painful or have pus. It can be spread by skin-to skin contact or by touching surfaces contaminated with the germ.

HOW DO YOU GET IT?

bacteria enters skin through a cut or a small break.
It’s spread by skin-to-skin contact.

it becomes more severe if it enters the bloodstream.

HOW TO AVOID IT

Avoid sharing personal items such as towels, sheets, razors, clothing and athletic equipment.

Keep wounds covered with sterile, dry bandages until they heal. Pus from infected sores often contains MRSA, and keeping wounds covered will help keep it from spreading.

Sanitize linens and wash gym and athletic clothes after each wearing.

Wash your hands. Scrub hands briskly for at least 15 seconds, then dry them with a disposable towel and use another towel to turn off the faucet. Carry a small bottle of hand sanitizer containing at least 62 percent alcohol.

Get tested. If you have a skin infection requiring treatment, ask if you should be tested for MRSA.

Source: Mayo Clinic

Article

Blair County High School Students Diagnosed With MRSA

Blair County High School Students Diagnosed With MRSA

10/26/2007 8:42 am

Four students from two Blair County are now the latest to have apparently contracted cases of Methicillin-Resistant Staphylococcus Aureus. It’s a bacterial skin infection commonly known as MRSA, and it can be deadly.

School officials say a student-athlete from Central High School in Martinsburg has been infected, as have three other students who attend classes in the Tyrone-Area School District. Spring Cove School District Superintendent Rodney Green reports that their student’s MRSA case was confirmed on Monday, and that prompted district officials to take quick action to keep the incident isolated.

The district has sent letters home to student’s parents explaining the situation. Green says the infected student realized there was a problem with a skin infection he acquired last week and he sought immediate medical treatment. The student had already been on antibiotics before the official MRSA confirmation was made.

Local health officials are calling the student’s cases an “isolated incident.”

Green says his district’s student has a community-acquired form of the bacteria, which is common among student athletes and can be treated with antibiotics. WRTA News has so far been unable to confirm the exact details surrounding the three students who became infected in Tyrone.

© Copyright 2004-2007 by WRTA.com

Antibiotic Selection for Infections Involving Methicillin-Resistant Staphylococcus aureus

Antibiotic Selection for Infections Involving Methicillin-Resistant Staphylococcus aureus

John G. Bartlett, MD

Choosing Appropriate Therapy for MRSA

The mainstay antibiotic for treatment of infections caused by MRSA has been vancomycin, a drug that was approved by the US Food and Drug administration (FDA) in 1956 but not used extensively until the last 20 years.[1] The escalating use of vancomycin is attributed to the increase in nosocomial infections caused by MRSA from 2% in 1974 to more than 50% in 2000.[1,21] Vancomycin is used mainly to treat patients with infections caused by MRSA, patients with infections caused by gram-positive bacteria in whom beta-lactam antibiotics are contraindicated, and patients with device- and catheter-associated infections.

Vancomycin has established efficacy and is currently recommended for endocarditic prophylaxis in penicillin-allergic patients undergoing invasive genitourinary or gastrointestinal procedures likely to result in transient bacteremia.[22] However, there are major concerns with the use of this drug. First, rapid infusion with vancomycin is associated with histamine release syndrome (red man syndrome), which usually can be corrected by slow infusion. However, 3% to 4% of patients appear to have true hypersensitivity reactions expressed as a maculopapular rash, and a small percentage have reversible marrow suppression.[21,23] Second, vancomycin is not available in an oral formulation for treatment of systemic infection, so patients are exposed to the risks and expenses of intravenous therapy. Third, some clinicians question the potency of vancomycin in selected settings because of slow clinical responses, clinical failures, and high rates of relapse.[24-28] Finally, many clinicians are concerned about the clinical significance of reduced susceptibility with VISA strains and the threat of vancomycin-resistant S aureus (VRSA).[17,18,29-31] Although the clinical significance of VISA is unclear,[16,29-31] the emergence of this organism alarmed those concerned about possibility of a vancomycin resistant strain. This became a reality in 2002, when the Centers for Disease Control and Prevention (CDC) published reports of 2 patients with infections caused by VRSA.[17,32] In both cases, the isolates contained the vanA gene of vancomycin resistance, presumably by transfer from vancomycin-resistant enterococci (VRE) at a co-infected site.

In April 2004, the CDC reported on the third documented clinical isolate of VRSA, which was obtained from a long-term care facility resident in New York.[33] On March 17, 2003, the isolate yielded S aureus, and laboratory tests indicated that it was resistant to vancomycin. Further testing revealed that the isolate contained both the mecA and vanA genes; however, the CDC states that the isolate appears unrelated epidemiologically to the 2 previously identified VRSA isolates. Although the New York isolate contained the vanA gene, the vancomycin MIC of the isolate appeared low when initially tested by an automated method. Vancomycin resistance was revealed using the broth microdilution reference method, a nonautomated testing technique. The CDC concluded that additional VRSA infections might have occurred but were undetected by laboratories using automated methods and recommends that potential VRSA isolates should be saved for confirmatory testing using nonautomated methods such as broth microdilution, agar dilution, or agar-gradient diffusion. The patient remains in a long-term care facility, and the New York State Department of Health continues to investigate this case

In the past 5 years, the FDA has approved 3 alternatives to vancomycin for treatment of infections caused by MRSA: quinupristin-dalfopristin, linezolid, and daptomycin. These agents have good in vitro activity against MRSA and most other clinically important gram-positive bacterial pathogens. A general comparison of these drugs is summarized in Table 3.

In addition, important advantages and disadvantages of these drugs include the following:

Quinupristin-dalfopristin is the first agent in the streptogramin class. It is indicated for the treatment of patients with serious or life-threatening infections associated with vancomycin-resistant Enterococcus faecium bacteremia and complicated skin and skin structure infections caused by S aureus and S pyogenes.[34] Investigators conducted a randomized, open-label, controlled clinical trial comparing quinupristin-dalfopristin 7.5 mg/kg q12h IV (n=221) with cefazolin 1g q8h IV (n=222) in the treatment of complicated skin and skin structure infections caused by suspected or confirmed MRSA. One hundred thirteen patients (51%) and 120 patients (54%) in the quinupristin-dalfopristin and cefazolin groups, respectively, were found to be clinically evaluable. Of these patients, the success rate was 66% in the quinupristin-dalfopristin group and 64% in the cefazolin group. In another trial, quinupristin-dalfopristin 7.5 mg/kg q12h IV (n=229) was compared with oxacillin 2 g q6h IV (n=221). Of the 105 patients (46%) in the quinupristin-dalfopristin arm and the 106 patients (48%) in the cefazolin arm who were found to be clinically evaluable, the success rate was 50% for those taking quinupristin-dalfopristin and 52% for those on cefazolin therapy.

The drug has a curious sensitivity profile, with activity against vancomycin-resistant E faecium but not against Enterococcus faecalis. Quinupristin-dalfopristin has been associated with venous irritation, which can be avoided if the drug is infused through a central line, and also with high rates of injection site reactions and often debilitating myalgias.

Linezolid is the first drug in the oxazolidinone class and is available in both oral and parenteral formulations. The oral formulation is nearly 100% bioavailable and is thus interchangeable with the parenteral formulation.[35] Linezolid is indicated in the treatment of vancomycin-resistant E faecium infections, nosocomial pneumonia caused by S aureus (methicillin-susceptible and -resistant strains) of Streptococcus pneumoniae (penicillin-resistant strains), complicated skin and skin structure infections including diabetic foot infections without concomitant osteomyelitis caused by S aureus, S pyogenes, and S agalactiae, and community-acquired pneumonia caused by S pneumoniae or S aureus.

In a randomized, multicenter, double-blind, double-dummy trial, 400 patients received linezolid 600 mg IV q12h followed by 600 mg PO q12h, and 419 patients received oxacillin 2g IV q6h followed by dicloxacillin 500 mg PO q6h. Two hundred forty-five (61%) patients in the linezolid arm and 242 patients (58%) in the oxacillin-dicloxacillin arm were clinically evaluable.

Cure rates were 90% in the linezolid group and 85% in the oxacillin-dicloxacillin group. The most common adverse events are nausea, vomiting, diarrhea, and headache, and cases of linezolid resistance have been reported.

Daptomycin is the most recent addition and represents a new class of antibiotics. Clinical trials showed good results in skin and soft tissue infections.[36] Adult patients with clinically documented complicated skin and skin structure infections were enrolled in 2 randomized, multinational, multicenter, investigator-blinded studies. One study was conducted primarily in the United States and South Africa, and the other was conducted at non-US sites only. A total of 534 patients received daptomycin 4 mg/kg IV q24h and 558 patients received the comparator drug, which consisted of either vancomycin 1 g q12h or a semisynthetic penicillin (ie, nafcillin, oxacillin, cloxacillin, flucloxacillin; 4-12 g IV per day). In the first study, clinical success rates in the clinically evaluable population were 76% (158/208) in the daptomycin group and 77% (158/206) in the comparator group. In the second study, clinical success rates in the clinically evaluable population were 89% (214/238) in patients taking daptomycin and 91% (226/250) in those treated with comparator drugs.

However, the failure rate of daptomycin was excessive in a controlled trial for community-acquired pneumonia. This observation is thought to be attributable to relatively poor penetration into epithelial lining fluid in the lung. Some authorities conclude that daptomycin may have a therapeutic niche with endocarditis caused by MRSA or VRE because of results in an animal model.[37] The most common adverse events include gastrointestinal disorders, general disorders (ie, injection site reactions, fever), and nervous system disorders.

Medscape

What are the criteria for distinguishing community-associated MRSA (CA-MRSA) from healthcare-associated MRSA (HA-MRSA)?

What are the criteria for distinguishing community-associated MRSA (CA-MRSA) from healthcare-associated MRSA (HA-MRSA)?

Persons with MRSA infections that meet all of the following criteria likely have CA-MRSA infections:

Diagnosis of MRSA was made in the outpatient setting or by a culture positive for MRSA within 48 hours after admission to the hospital.

No medical history of MRSA infection or colonization.

No medical history in the past year of:

Hospitalization
Admission to a nursing home, skilled nursing facility, or hospice
Dialysis
Surgery
No permanent indwelling catheters or medical devices that pass through the skin into the body.

What is the main way that staph or MRSA is transmitted in the community?

The main mode of transmission of staph and/or MRSA is via hands which may become contaminated by contact with a) colonized or infected individuals, b) colonized or infected body sites of other persons, or c) devices, items, or environmental surfaces contaminated with body fluids containing staph or MRSA. Other factors contributing to transmission include skin-to-skin contact, crowded conditions, and poor hygiene.

How is a MRSA infection diagnosed?

In general, a culture should be obtained from the infection site and sent to the microbiology laboratory. If S. aureus is isolated, the organism should be tested as follows to determine which antibiotics will be effective for treating the infection.

Skin Infection: Obtain either a small biopsy of skin or drainage from the infected site. A culture of a skin lesion is especially useful in recurrent or persistent cases of skin infection, in cases of antibiotic failure, and in cases that present with advanced or aggressive infections.

Pneumonia: Obtain a sputum culture (expectorated purulent sputum, respiratory lavage, or bronchoscopy).

Bloodstream Infection: Obtain blood cultures using aseptic techniques.

Urinary Infection: Obtain urine cultures using aseptic techniques.

How are CA-MRSA infections treated?

Staph skin infections, such as boils or abscesses, may be treated by incision and drainage, depending on severity. Antibiotic treatment, if indicated, should be guided by the susceptibility profile of the organism.

How do CA-MRSA and HA-MRSA strains differ?

Recently recognized outbreaks of MRSA in community settings have been associated with strains that have some unique microbiologic and genetic properties compared with the traditional hospital-based MRSA strains, suggesting some biologic properties (e.g., virulence factors) may allow the community strains to spread more easily or cause more skin disease. Additional studies are underway to characterize and compare the biologic properties of HA-MRSA and CA-MRSA strains.

There are at least three different S. aureus strains in the United States that can cause CA-MRSA infections. CDC continues to work with state and local health departments to gather organisms and epidemiologic data from known cases to determine why certain groups of people get these infections.

Are MRSA infections a reportable disease?

MRSA is reportable in several states. The decision to make a particular disease reportable to public health authorities is made by each state, based on the needs of that individual state. To find out if MRSA is reportable in your state, call your state health department.

CDC

MRSA Information for the Public

MRSA Information for the Public

What is Staphylococcus aureus (staph)?

Staphylococcus aureus, often referred to simply as "staph," are bacteria commonly carried on the skin or in the nose of healthy people. Approximately 25% to 30% of the population is colonized (when bacteria are present, but not causing an infection) in the nose with staph bacteria. Sometimes, staph can cause an infection. 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). However, staph bacteria also can cause serious infections (such as surgical wound infections, bloodstream infections, and pneumonia).

What is MRSA (methicillin-resistant Staphylococcus aureus)?

Some staph bacteria are resistant to antibiotics. MRSA is a type of staph that is resistant to antibiotics called beta-lactams. Beta-lactam antibiotics include methicillin and other more common antibiotics such as oxacillin, penicillin and amoxicillin. While 25% to 30% of the population is colonized with staph, approximately 1% is colonized with MRSA.

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 know 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.

How common are staph and MRSA infections?

Staph bacteria are one of the most common causes of skin infection in the United States and are a common cause of pneumonia, surgical wound infections, and bloodstream infections. The majority of MRSA infections occur among patients in hospitals or other healthcare settings; however, it is becoming more common in the community setting. Data from a prospective study in 2003, suggests that 12% of clinical MRSA infections are community-associated, but this varies by geographic region and population.

What does a staph or MRSA infection look like?

Staph bacteria, including MRSA, can cause skin infections that may look like a pimple or boil and can be red, swollen, painful, or have pus or other drainage. More serious infections may cause pneumonia, bloodstream infections, or surgical wound infections.

Are certain people at increased risk for community-associated staph or MRSA infections?

CDC has investigated clusters of CA-MRSA skin infections among athletes, military recruits, children, Pacific Islanders, Alaskan Natives, Native Americans, men who have sex with men, and prisoners.Factors that have been associated with the spread of MRSA skin infections include: close skin-to-skin contact, openings in the skin such as cuts or abrasions, contaminated items and surfaces, crowded living conditions, and poor hygiene.

How can I prevent staph or MRSA skin infections?

Practice good hygiene:

Keep your hands clean by washing thoroughly with soap and water or using an alcohol-based hand sanitizer.

Keep cuts and scrapes clean and covered with a bandage until healed.

Avoid contact with other people’s wounds or bandages.

Avoid sharing personal items such as towels or razors.

Are people who are positive for the human immune deficiency virus (HIV) at increased risk for MRSA?

Should they be taking special precautions?

People with weakened immune systems, which include some patients with HIV infection, may be at risk for more severe illness if they get infected with MRSA. People with HIV should follow the same prevention measures as those without HIV to prevent staph infections, including practice good hygiene, cover wounds (e.g., cuts or abrasions) with clean dry bandages, avoid sharing personal items such as towels and razors, and contact their doctor if they think they have an infection.

Can I get a staph or MRSA infection at my health club?

In the outbreaks of MRSA, the environment has not played a significant role in the transmission of MRSA. MRSA is transmitted most frequently by direct skin-to-skin contact. You can protect yourself from infections by practicing good hygiene (e.g., keeping your hands clean by washing with soap and water or using an alcohol-based hand rub and showering after working out); covering any open skin area such as abrasions or cuts with a clean dry bandage; avoiding sharing personal items such as towels or razors; using a barrier (e.g., clothing or a towel) between your skin and shared equipment; and wiping surfaces of equipment before and after use.

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

See your healthcare provider.

Are staph and MRSA infections treatable?

Yes.

Most staph and MRSA infections are treatable with antibiotics. If you are given an antibiotic, take all of the doses, even if the infection is getting better, unless your doctor tells you to stop taking it. Do not share antibiotics with other people or save unfinished antibiotics to use at another time.

However, many staph skin infections may be treated by draining the abscess or boil and may not require antibiotics. Drainage of skin boils or abscesses should only be done by a healthcare provider.

If after visiting your healthcare provider the infection is not getting better after a few days, contact them again. If other people you know or live with get the same infection tell them to go to their healthcare provider.

Is it possible that my staph or MRSA skin infection will come back after it is cured?

Yes. It is possible to have a staph or MRSA skin infection come back (recur) after it is cured. To prevent this from happening, follow your healthcare provider’s directions while you have the infection, and follow the prevention steps after the infection is gone.

If I have a staph, or MRSA skin infection, what can I do to prevent others from getting infected?

You can prevent spreading staph or MRSA skin infections to others by following these steps:

Cover your wound.

Keep wounds that are draining or have pus covered with clean, dry bandages.

Follow your healthcare provider’s instructions on proper care of the wound.

Pus from infected wounds can contain staph and MRSA, so keeping the infection covered will help prevent the spread to others. Bandages or tape can be discarded with the regular trash.

Clean your hands.

You, your family, and others in close contact should wash their hands frequently with soap and warm water or use an alcohol-based hand sanitizer, especially after changing the bandage or touching the infected wound.

Do not share personal items.

Avoid sharing personal items such as towels, washcloths, razors, clothing, or uniforms that may have had contact with the infected wound or bandage. Wash sheets, towels, and clothes that become soiled with water and laundry detergent. Drying clothes in a hot dryer, rather than air-drying, also helps kill bacteria in clothes.

Talk to your doctor.

Tell any healthcare providers who treat you that you have or had a staph or MRSA skin infection.

What should I do if someone I know has a staph or MRSA infection?

If you know someone that has a staph or MRSA infection you should follow the Prevention Steps

Welcome to MRSA Information

Welcome to MRSA Information, a blog dedicated to seperating fact from fiction, changing fears to understanding and hopefully providing us an avenue of successful prevention and treatment of this serious emerging infection.

What does MRSA stand for?

In short it means Methicillin-resistant Staphylococcus aureus.

What is MRSA?

MRSA is a type of Staphylococcus aureus resistant to certain antibiotics including methicillin and the more common antibiotics such as oxacillin, penicillin, and amoxicillin. MRSA incidence is on the rise in the U.S. and it has now become recognized as a major community-acquired pathogen.

In our blog we will share evidence based, peer reviewed information relating to causes, prevention, treatment, research and the future prognosis and control.

Pat O'Connor