New MRSA guidelines specify infection treatment

For many patients with a simple skin abscess, incision and drainage alone is adequate treatment, according to new guidelines for managing methicillin-resistant Staphylococcus aureus infections.

Physicians should combine antibiotics with such care when there are multiple infection sites and when the abscess is in an area that is difficult to drain, such as the face and hands, say new recommendations issued by the Infectious Diseases Society of America. Antibiotics should be prescribed when there is rapid progression of associated cellulitis, symptoms of systemic illness and associated comorbidities, including diabetes.

IDSA's first clinical practice guidelines on treating MRSA in adults and children were published online Jan. 4 in Clinical Infectious Diseases. The recommendations come as many physicians are struggling to manage the nation's uptick in health care- and community-associated MRSA cases with a limited number of antibiotics that can effectively treat the infections.

"The guidelines are meant to provide a framework to help physicians decide how to best evaluate and treat these infections," said lead guidelines author Catherine Liu, MD.

"It's important to remember that management of all MRSA infections should include identifying and eliminating the primary source or other sites of infection. ... There are other components to the treatment of these infections than just antibiotics," said Dr. Liu, an assistant clinical professor in the Division of Infectious Diseases in the Dept. of Medicine at the University of California, San Francisco.

MRSA is responsible for about 60% of skin infections seen in emergency departments, according to the IDSA. Less common, but more serious, is invasive MRSA, which kills an estimated 18,000 people each year, the society said. Such critical cases include pneumonia and infections of the blood, heart, bone, joints and central nervous system.

A panel of 13 infectious disease specialists developed the new recommendations for treating the "superbug" after analyzing hundreds of studies that were published between 1961 and 2010. The guidelines were reviewed and endorsed by the American Academy of Pediatrics, American College of Emergency Physicians and Pediatric Infectious Diseases Society.

Recommendations for primary care doctors

Key for primary care physicians are recommendations on treating skin and soft tissue infections associated with community-acquired MRSA and managing the recurrence of such conditions, which often are seen in the outpatient setting, Dr. Liu said.

In 2005, there were an estimated 14 million outpatient visits for suspected S. aureus skin and soft tissue infections in the U.S., according to the most recent data from the Centers for Disease Control and Prevention. Infectious diseases experts said the number of such visits probably has increased since then.

Also gaining attention is the growing number of children hospitalized with MRSA, said Meg Fisher, MD, immediate past chair of the AAP's Section on Infectious Diseases. In 1999, there were two cases of MRSA per 1,000 hospital admissions of children younger than 18, according to a May 2010 Pediatrics study of more than 64,000 children nationwide. The rate climbed to 20.7 cases per 1,000 admissions in 2008.

Among the most common MRSA-related challenges for pediatricians is that the bacterium tends to cause repeated and recurrent infections, Dr. Fisher said. "Everyone was hoping that the guidelines would say something definitive, but unfortunately the recommendations are pretty weak [on this topic]," said Dr. Fisher, pediatric infectious diseases specialist and medical director of the Children's Hospital at Monmouth Medical Center in New Jersey.

To prevent recurrent infections, IDSA suggests that physicians instruct patients to cover wounds that are draining with clean, dry bandages; wash themselves and their hands regularly; and avoid reusing or sharing personal items, such as razors and towels. Doctors also should encourage patients to clean surfaces that come in frequent contact with people's bare skin, such as counters and doorknobs.

Oral antibiotics can be prescribed for active infections that persist after patients improve their wound care and hygiene.

For children with minor skin infections, such as impetigo and secondarily infected skin lesions, including eczema, the antibiotic ointment mupirocin 2% can be used. IDSA recommends administering vancomycin to hospitalized children with complicated skin and soft tissue infections. Tetracyclines should not be used in children younger than 8 years.

The guidelines state that there are areas of controversy in which data are limited or conflicting and where additional research is needed. Such areas include the optimal management of recurrent skin and soft tissue infections and persistent MRSA bacteremia and vancomycin treatment failures.

"Hopefully, we'll have some more information to guide physicians on what the optimal regimen is for treating MRSA," Dr. Liu said. "This is the best we can provide people with now."