Public Release: 

Nasal antibiotic ointment reduces infection risk after surgery

Johns Hopkins Medicine

In what may be the largest clinical trial to evaluate the effectiveness of antimicrobial agents in preventing surgical wound and hospital-based infections caused by Staphylococcus aureus, scientists at the University of Iowa and Johns Hopkins found that an antibiotic ointment, called mupirocin (moo-PIE-roe-sin), smeared inside the nose cut infection rates in half or better.

"Our results carry tremendous implications for reducing S. aureus surgical wound and other hospital-based infections, and for preventing illness and saving lives," says Trish Perl, M.D., associate professor of medicine, director of Hospital Epidemiology and Infection Control at Hopkins and an author of the study published in the June 13 issue of the New England Journal of Medicine.

Staphylococcus aureus is a widely distributed germ that normally resides in the nostrils of an estimated 25 to 30 percent of all hospitalized patients without causing harm. But it can contaminate surgical sites, causing severe and often deadly infections, especially in people with weakened immune systems, and contributing millions of dollars yearly to the costs of health care.

In the study, called MARS (for Mupirocin and the Risk of Staphyloccus aureus Infections), the researchers determined the rate of S. aureus surgical wound infections and other hospital-based infections in 4,030 adult patients who underwent various elective surgical procedures at the University of Iowa Hospitals and Clinics and the Veteran's Affairs Medical Center in Iowa City. Mupirocin antibiotic ointment, or a placebo, was applied to the inside of the nostrils twice daily for up to five days before surgery. Patients were followed for 30 days after surgery to determine if they acquired S. aureus infections.

While mupirocin ointment, made by GlaxoSmithKline, is highly effective at reducing the rate of S. aureus infections in patients undergoing surgery, as with any antibiotic, there is the risk of widespread resistance.

"This is a terrific drug, but the downside is that resistance does develop with overuse," says Perl. "You don't want to bathe the hospital in mupirocin. It is incumbent upon us as clinicians to use this drug in high risk patients when studies support its use."

Perl and colleagues looked at both non-resistant and resistant strains of S. aureus and found that a short, carefully planed mupirocin treatment - like that used in the study - does not appear to contribute to antibiotic resistance. Perl cautions that mupirocin use should be selective.


Other authors of the study are Joseph Cullen, M.D., Richard Wenzel, M.D., M.Sc., M. Bridget Zimmerman, Ph.D., Michael Pfaller, M.D., Deborah Sheppard, Jennifer Twombley, R.N., Pamela French, M.D., M.P.H., and Loreen Herwaldt, M.D. The study was funded by a research grant from GlaxoSmithKline.

On the Web: Johns Hopkins Infectious Diseases: Johns Hopkins Hospital Epidemiology and Infection Control:

The study was funded by a research grant from GlaxoSmithKline. Dr. Perl is paid by GlaxoSmithKline as a lecturer. The terms of this arrangement are being managed by the Johns Hopkins University in accordance with its conflict of interest policies.

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