Program Dramatically Reduces MRSA Surgical-site Infections

A quality-improvement project was found to dramatically reduce the rate of infections caused by methicillin-resistant Staphylococcus aureus (MRSA), according to a study published in the Archives of Internal Medicine.

Despite advances in infection control and prevention, surgical-site infections (SSIs) caused by MRSA continue to plague certain types of surgery, including cardiothoracic procedures; according to Edward E. Walsh, MD, the study’s lead author, MRSA wound infections following cardiac surgery have increased in recent years and carry significant morbidity and mortality.

At Rochester General Hospital, a large, a community-based hospital in New York State, MRSA accounted for 56% of postoperative infections. In order to improve the rate of MRSA infections on the cardiac surgical service, Walsh and colleagues initiated a quality-improvement program in February of 2007, comparing postoperative wound infection rates for the 3 years before and after introduction of a comprehensive MRSA intervention program.

According to the study, the intervention included preoperative screening for MRSA colonization, administration of intravenous vancomycin prophylaxis for identified carriers, administration of intranasal mupirocin calcium ointment to all patients regardless of colonization status for five days beginning the day before surgery, and application of mupirocin to chest tube sites at the time of removal. Patients were also rescreened upon discharge from the hospital.

SSI rates were compared between two groups: a baseline cohort of 2,766 patients who underwent cardiothoracic surgery between 2004 and 2007, and an intervention cohort of 2,496 patients who underwent such surgery between 2007 and 2010.

Researchers found that the MRSA SSI rate was 93% lower in the intervention cohort than in the baseline cohort, and that overall wound infection rates decreased from 2.1% to 0.8%. This reduction was “predominantly attributable to the decrease in MRSA SSIs,” they said, noting that the rate of SSIs caused by other organisms was similar between groups. During the intervention period, there was no change in the number of MRSA infections after noncardiac surgery.

“This MRSA intervention program, in which all patients receive intranasal mupirocin and patients colonized with MRSA receive vancomycin prophylaxis, has resulted in a near-complete and sustained elimination of MRSA wound infections after cardiac surgery,” they concluded.

In a comment of the study published in Journal Watch Infectious Diseases, Larry M. Baddour, MD, professor of medicine and chairman in the division of Infectious Diseases at Mayo Clinic College of Medicine, noted that “limitations in the study design could have resulted in underreporting of SSIs diagnosed after hospital discharge.” However, he said that “the impressive drop in MRSA cardiothoracic SSIs should prompt further evaluation of the prevention measures used in this investigation.”

For more information on this topic:

• Key Targets Identified for MRSA Vaccine
• How do you sanitize your smartphone in the hospital?
• MRSA: Hospital Prevention of New Infections