IDSA announces first guidelines for treatment of MRSA infections

An antibiotic-resistant "superbug," MRSA is responsible for about 60 percent of skin infections seen in emergency rooms. The guidelines address treatment of these common infections, which are frequently mistaken for spider bites. They also address treatment of invasive MRSA, which is less common but far more serious, including pneumonia and infections of the blood, heart, bone, joints and central nervous system. Invasive MRSA kills about 18,000 people every year.

To be published in the Feb. 1 issue of Clinical Infectious Diseases, the guidelines are intended to guide physicians in their use of antibiotics for treatment of this common infection. Current treatment varies widely.

"MRSA has become a huge public health problem and physicians often struggle with how to treat it," said Catherine Liu, MD, lead author of the guidelines and assistant clinical professor in the Division of Infectious Diseases, University of California, San Francisco. "The guidelines establish a framework to help physicians determine how to evaluate and treat uncomplicated as well as invasive infections. It's designed to be a living document, meaning the recommendations will evolve as new information and antibiotics become available."

MRSA is a type of Staphylococcus aureus ("staph") bacterium that is resistant to first-line antibiotics. Although MRSA can be treated with other types of antibiotics, its resistance to those antibiotics is increasing as well. Overuse and misuse of antibiotics contribute to drug resistance, and the guidelines note that uncomplicated skin infections often can be treated without the use of antibiotics. The guidelines also call for the development of new and better antibiotics to treat invasive MRSA.

MRSA has been a concern in hospitals for decades (hospital-associated MRSA or HA-MRSA), but in the last 15 years, community strains of MRSA (community-associated MRSA or CA-MRSA) have become a serious problem among healthy people outside of the hospital. CA-MRSA often is spread in locker rooms, dormitories, jails and prisons, in homes and at daycare centers, usually through direct contact or by an object used by an infected person – such as towels, razors and sports equipment. It most frequently causes painful red, swollen bumps about the size of a pencil eraser or golf ball. These bumps often are filled with pus and can appear anywhere on the body, most often at the site of a cut or abrasion or areas covered by hair, such as the back of the neck, groin, buttocks and armpits.

MRSA is a bigger concern when it invades the body beyond the skin. An estimated 94,360 invasive MRSA infections occurred in the United States in 2005, and more than 18,000 people who were infected died, according to a large study published in the Journal of the American Medical Association. Most invasive disease was due to hospital-associated MRSA, but about one in seven cases was due to community-associated MRSA.

Good hygiene is the best defense against MRSA, according to the Centers for Disease Control and Prevention (CDC), including keeping the hands clean, keeping cuts and scrapes clean and covered with a bandage, avoiding contact with other people's wounds, and avoiding sharing personal items such as towels or razors.

The IDSA guidelines address a variety of infections caused by MRSA commonly encountered by emergency room doctors, pediatricians, primary care physicians, hospitalists, infectious diseases specialists, pharmacists and other health care providers. Topics include: how to manage skin and soft tissue infections likely caused by community-associated MRSA; how to treat recurrent skin infections; recommendations regarding use of the intravenous antibiotic vancomycin and other antibiotics used for the treatment of MRSA; how to manage invasive infections, such as pneumonia, and infections in the bones, joints, blood or heart; and how to treat newborns who are infected with MRSA.

The guidelines were reviewed and endorsed by the Pediatric Infectious Diseases Society, the American College of Emergency Physicians, and the American Academy of Pediatrics. The voluntary guidelines are not intended to take the place of a doctor's judgment, but rather support the decision-making process, which must be individualized according to each patient's circumstances.

The 13-member guidelines panel comprised of MRSA experts from around the country reviewed hundreds of scientific studies, papers and presentations. In addition to Dr. Liu, the MRSA guidelines panel includes: Arnold Bayer, Sara E. Cosgrove, Robert S. Daum, Scott K. Fridkin, Rachel J. Gorwitz, Sheldon L. Kaplan, Adolf W. Karchmer, Donald P. Levine, Barbara E. Murray, Michael J. Rybak, David A. Talan, and Henry F. Chambers.

Provided by Infectious Diseases Society of America