Correctional Medicine Institute

METHICILLIN-RESISTANT STAPHYLOCOCCUS
AUREUS (MRSA) IN THE HEADLINES

By Louis C. Tripoli, MD

Adjunct Assistant Professor of Medicine, Infectious Diseases, Johns Hopkins University

October 31, 2003

MRSA infection has been making the headlines all over the country. This infection is, of course, no stranger to correctional medicine, but as usual, it presents unique dimensions in the correctional setting and ones that require significant attention by providers as well as patient education and infection control professionals.

While MRSA has been present in the hospital setting for a considerable period of time, its emergence as a pathogen outside of hospitals has only recently become a problem. Traditionally, microorganisms that develop high-level resistance pay a competitive price to carry that antibiotic resistance. However, the staphylococcus aureus organism seems to defy all of the rules and this particular bug appears to be as virulent in its resistant form as it is in its wild type.

By the way, oxacillin resistance (ORSA) is equivalent to methicillin resistance (MRSA).

Is it a spider bite? Is it a skin-munching infection? Will it kill you? These are many of the questions that are posed by people who develop MRSA infection. In fact, most MRSA infections are minor infections of the skin which take the form of furuncles as well as pustules or boils. Generally, these conditions are self-limited. It is not always necessary to treat every infection aggressively. However, in the correctional setting there has been significant amount of misinformation on the "inmate grapevine" that attributes these otherwise unremarkable lesions to, most often, arachnid bites. In point of fact, arachnids rarely bite people, and most of the bites are inconsequential. The most significant injury can occur from envenomation by spider venom which is complex and has many potential side effects. However, a dissertation on spider venom is not within the scope of this particular article. Aside from the systemic effects of spider venom, it is commonly recognized that the bite of a brown recluse spider can have significant local effects on the skin. Again, the brown recluse Loxosceles reclusa is a spider that prefers, as its name suggests, isolated areas and is a rather shy and timid organism. It only bites when provoked or when trapped in clothing and most characteristically the bites occur at areas where the spider might settle in the clothing, such as the waistband. It is unusual for the spider to bite multiple times. It is found in the Midwest and Southeast and hibernates during the winter, so bites occur between March and October.

The skin may exhibit a hive (urticarial) lesion, a papule, or a pustule. In severe reactions, patients may develop systemic signs including rash, fever, headache, and other flu-like symptoms. The bite is generally painless. Only a small proportion of bites become necrotic, and the progression follows a characteristic pattern: a central blister with purple-gray discoloration (in Caucasians), surrounded by a white ring of blanched skin and a much larger halo of red. The lesion is termed the "red, white, and blue" sign. If skin breakdown occurs, the site becomes painful. It usually progress to a black eschar and may be slow to heal.

The misinterpretation of minor skin lesions as spider bites has led to a certain amount of litigation in various prison systems. Ironically, there is probably more potential harm to the inmate by the use of the chemicals that are used to eradicate spiders -- which aren't really there -- as opposed to the potential danger from a brown recluse spider.

Guidelines

Without a doubt, the best guideline in correctional medicine for the management of MRSA infection was provided by the Federal Bureau of Prisons authored by Newton Kendig, II, M.D., Capt. United States Public Health Service. There are some great advantages to these guidelines. First, they are available for free in the public domain and can be found on the website www.nicic.org. It takes a little bit of sleuthing to find the site where the guidelines are located, but the search is well worth it. In this document, Dr. Kendig and his staff lay out the issues surrounding methicillin-resistant staphylococcus aureus and its management in the correctional environment in a concise and reader-friendly way. Some of the more important and convenient aspects of this document include specific recommendations for management in the correctional setting. For example, these recommendations talk about the conservative management of minor skin lesions and the role of culture. It is important to understand that in most cases culture is not possible because there is no draining lesion. However, in the case of serious, deep, draining lesions, staphylococcal pneumonia or staphylococcal sepsis, the appropriate bodily fluid should be cultured.

Empiric treatment of most people without risk factors for MRSA should be undertaken with the usual antibiotics. However, there are segments of the population that may be at risk for MRSA and the clinician may wish to treat with antibiotics that are appropriate for this infection. These subsets include injection drug users, persons with type 1 diabetes mellitus, persons on Hemodialysis, those with AIDS, and people who have recently had surgery. Other factors that favor colonization with MRSA include: those with intravenous lines, patients who have recently been in a hospital, patients who have been on antistaphylococcal antibiotics in the recent past, patients with indwelling catheters or other hardware, and patients who have had a previous history of methicillin-resistant staphylococcus infections.

Unlike Smallpox, Staph doesn't fly. MRSA and other staphylococcal organisms are transferred from one person to another by contaminated hands. This is not a pathogen spread by aerosol.

Infection control is very important as well as decontamination of the environment and adherence to isolation policies. Dr. Kendig's document walks the reader through those various isolation procedures and summarizes them well.

While physicians tend to focus on treatment such as drainage and antibiotics, one cannot say enough about the importance of educating staff in the containment of this serious pathogen. For example, correctional officers need to be trained about what to do when handling an inmate with methicillin-resistant staphylococcus aureus.

Patient education: The Federal Bureau guideline contains a one-page handout. Various people are developing patient education aids such as videotapes and even meetings with infection control specialists. For those of you reading this article, it would be very helpful for the rest of us to hear about what you have done in your setting. (Please write to Ltripoli@pol.net)

Infection control measures can never be overemphasized. I am always amazed at the neglect of hand washing in the medical environments that I work in and visit. For example, I continue to notice that even in the hospital many healthcare professionals neglect hand washing to this day despite numerous admonitions over the years. In addition, many hospitals and public restrooms are set up so that people re-contaminate their hands after washing them.

The use of alcohol-containing antiseptic scrubs is common in the non-correctional setting, but because of security concerns, these particular disinfectants are not as available in the correctional setting as outside. It should be emphasized that adequate hand washing requires about 15-30 seconds with soap and water. In addition, surfaces that are used by multiple people should be decontaminated. This is especially true in the area of electronic medical records, where many people use the same keyboard over and over again, touch the same doorknobs, and use the same telephones. In particular with regard to staphylococcus, laundry should be washed in hot water for at least 25 minutes to be sure that the germ has been exterminated. Simple personal hygiene measures such as not sharing personal equipment with people who have MRSA infections should be emphasized to the inmates. An important aspect of correctional officer training is to facilitate inmate reporting of even minor-appearing skin infections so that there can be measures taken to make sure that this does not represent a methicillin-resistant staphylococcus outbreak.

Antibiotics

Another feature of this fine document is a listing of the appropriate antibiotics for methicillin-resistant Staph aureus infection. Many physicians do not know, for example, that trimethoprim-sulfamethoxazole is usually useful in patients who have MRSA, but it should be combined with rifampin, according to Kendig. In addition, an antibiotic in combination with rifampin should be used in all serious infections with the exception of vancomycin and linezolid. Both of these may be used as monotherapy. Linezolid has the advantage of being able to be given twice a day and can be used as monotherapy, but it is quite expensive. However, the expense may be worth it when compared to sending a patient to the hospital or to the infirmary for intravenous vancomycin. The clinician should remember that oral vancomycin is useless in systemic staphylococcal infections and should only be used to treat gastrointestinal overgrowth with Clostridium difficile.

Note that rifampin is never used alone to treat Staph infections, regardless of sensitivity results. It is also not generally used to eradicate carriage (it is used for this purpose to eradicate the carriage of Neisseria meningitidis). Local application of mupirocin is used for this purpose. Dr. Kendig's document contains specific instructions on how to apply this therapy.

As with all complex infectious diseases, involving a specialist is important, whether as a formal consultation or as an advisor. In some prisons, we involve the consultant with the primary care medical staff via teleconferencing, a process we have deemed "telementoring."

A new antibiotic, daptomycin, has recently been approved for Staphylococcal infections. It is not mentioned in the BOP document, probably because of its recent appearance. Here is some brief information about this new drug:

Daptomycin (Cubicin™)

Manufacturer: Cubist Pharmaceutical

Cost (AWP): $134.49/500mg vial ($75.31 per day for a 70kg patient)

FDA Indications

Treatment of complicated skin and skin structure infections caused by susceptible strains of Gram-positive microorganism (including MSSA and MRSA)

Usual Adult Dose

4mg/kg IV qd (FDA approved dose)

6mg/kg IV qd (ongoing trials for bacteremia and endocarditis, closer monitoring for myopathy recommended)

Daptomycin, a new cyclic lipopeptide, parenteral antibiotic with a spectrum of activity that is similar to linezolid which includes virtually all Gram positive organism including E. faecalis and E. faecium (including VRE) and S. aureus (including MRSA). A theoretical advantage of daptomycin for certain infections (i.e. endocarditis) is its bactericidal activity against MRSA and Enterococcus.

Daptomycin should not be used for pneumonia due to higher failure in clinical trials. Until more clinical data becomes available, daptomycin should not be relied upon for CNS or bone infections due to poor penetration of these tissues.

The Federal Bureau of Prisons' document also recommends the reporting and tracking of patients with methicillin-resistant staphylococcus aureus and offers a convenient form to do so. In addition, a very useful patient education handout appears at the end of the document.

Outbreaks (2 or more infections by the same strain in the same place):

The Federal Bureau of Prisons document again gives detailed instructions on managing outbreaks and defines an outbreak as the occurrence of methicillin-resistant staphylococcus infections in two or more patients at the same time with similar antibiotic-resistant patterns. Patient movement should be restricted by security staff in cases of patients who have confirmed methicillin-resistant staphylococcus infection.

Lets face it; antibiotic-resistant organisms are here to stay. The overuse of antibiotics has contributed to this problem and our current armamentarium for treating resistant infections will probably only be useful for another 5-10 years. We may be smarter than the germs, but they outnumber us by a significant amount. The lessons learned from containing methicillin-resistant staphylococcus aureus may also be applicable to other infections that we haven't even thought of but are certainly coming. Once again, the correctional healthcare provider is on the forefront of public health by our efforts to understand and control this significant infectious disease problem in our institutions. It is always important to develop bridges to noncorrectional public health agencies, not only to exchange information, but also to plan for transition of inmates from one setting to another who may have methicillin-resistant staphylococcus aureus. As usual, the correctional healthcare providers' public health duty does not end at the prison door.