MRSA becoming more prevalent among outpatients — What should you do?

Cases of methicillin-resistant Staphylococcus aureus (MRSA) are increasing among outpatients and driving up costs; in fact, a just-released study indicates that the proportion of MRSA increased more than 90% among outpatients with staph over the course of the study.1

"I think what we're seeing, what the data definitely are showing us, is that MRSA is much more prevalent in the community as a whole," says Linda R. Greene, RN, MPS, CIC, director of infection prevention and control, Rochester (NY) General Health System, and member of the board of directors for the Association for Professionals in Infection Control and Epidemiology (APIC). Indeed, the study found a seven-fold increase in the proportion of community-acquired strains of MRSA in outpatient hospital units between 1999 and 2006.

"If you are an outpatient surgery manager, you have to have a high level of awareness that there are not only people who have had previous hospitalizations and have the health care-acquired strain, but there are young, relatively healthy people who have the community-acquired strains," she says.

In a study just published by Duke University Hospital, in Durham, NC, post-surgical infections due to MRSA can cost as much as $60,000 per patient.2

Deverick J. Anderson, MD, MPH, an infectious diseases specialist at Duke University Medical Center and lead author of the study, said, "We found that patients with surgical-site infections [SSIs] due to MRSA were 35 times more likely to be readmitted and seven times more likely to die within 90 days compared to uninfected surgical patients. These patients also required more than three weeks of additional hospitalization and accrued more than $60,000 in additional charges."

The researchers found most of the outcomes for MRSA compared to methicillin-sensitive Staphylococcus aureus (MSSA) were worse, as anticipated; however one finding was surprising, according to Anderson. "Our findings show that methicillin resistance contributed to longer hospital stays and increased hospital charges but did not increase the risk of mortality," he said.

The data show that patients with surgical-site infections due to MRSA compared to MSSA on average required six more days of hospitalization and incurred $24,000 in additional charges. "For the seven hospitals we looked at, the total estimated cost resulting from surgical-site infections due to MRSA was more than $19 million," Anderson said.

MRSA kills about 20,000 people in the United States each year, according to a statement released with the study.3 The study's authors say that infection control policies should consider the role of outpatients in the spread of MRSA and that policies should promote interventions to prevent MRSA from spreading from outpatient to inpatient areas. However, some infection control experts take a different approach.

Alex Kallen, MD, medical epidemiologist at the Centers for Disease Control and Prevention (CDC), says, "It makes more sense the other way: Prevent inpatient going to outpatient." Kallen points out that while hospital-based MRSA has existed since the 1960s or '70s, primarily in hospitals, the community-associated MRSA "developed out of the blue." "It seems like outpatient surgery centers see themselves on the border between these two things," he says.

Preoperative screening for MRSA is controversial and not routinely recommended, say sources interviewed by Same-Day Surgery. However, early results of a study in Otolaryngology — Head and Neck Surgery showed potential benefit in pre-op screening for Staphylococcus aureus (SA) for reducing MRSA infection rates.4 Screening and treatment of MRSA-colonized patients preoperatively might reduce infectious complications in otolaryngology, the authors found. However, larger studies are needed, they added.

Approach screening on a case-by-case basis, advises Henry F. Chambers, MD, professor of medicine in the Division of Infectious Diseases, University of California, San Francisco. "For example, depending on procedure, consider the risk of the procedure for being infected, and whether the patient population has post-op infections caused by MRSA," Chambers says.

Track patient infections so you know the infection rate by procedure, he advises. "Regardless of what organism causes the infection, if your rate is too high, steps need to be taken to correct that," he says. "If there are a lot of complicating infections caused by MRSA, look at your infection control practices." In the outpatient setting, when you see infections, "MRSA is on the table as a possibility causing that infection," Chambers says.

However, in Chambers' view, "screening patients is overemphasized as a first step." Kallen says strains of SA are spread from one person to another "with the health care worker in between." His advice? "Use common sense," he says. Infection control experts offer these suggestions:

Consider preoperative antibiotics.

The preoperative antibiotic is important since the drug is targeted at those microorganisms that normally colonize the skin and could subsequently get into the surgical wound, Greene says. Guidelines in the Surgical Care Improvement Project (SCIP) call for the antibiotic to be administered within one hour prior to surgery, she says. For some drugs such as vancomycin, the guidelines allow for a two-hour time period, Greene says.

"Recommendations for preoperative antibiotics suggest that when patients are known to be colonized or infected with MRSA, a drug that targets MRSA should be added or substituted in the preoperative antibiotic regime," she says. "This would hopefully reduce the risk that patients who carry MRSA on their skin would become infected with MRSA in the surgical wound."

Perform a thorough nursing assessment.

Because outpatient surgery patients might be carriers of MRSA, or infected with the disease, a "very good patient assessment" is important, Greene says. An accurate assessment is important prior to surgery. Providers should ascertain patient history including previous history of resistant organisms such as MRSA as part of the routine preoperative history and physical. Likewise, on presentation to the preoperative area, a through patient assessment would include routine vital signs, skin assessment including any new skin lesions, history of MRSA, verification of the information obtained preoperatively, and any changes since the preoperative history and physical. With the community-acquired strains, the disease might present as what appears to be a spider bite or a boil, she says.

Practice good hand antisepsis.

Clean your hands after contact with people, Kallen advises. "If there are open or draining MRSA wounds, keep them covered, and practice hand hygiene before and after contact with that wound," he says.

Use gloves, Green emphasizes. "Just because you're in an outpatient setting, it doesn't mean you shouldn't have those things available; so if someone has secretions, excretions, drainage, there's gloves and personal protective equipment" available, she says.

Educate patients to remind caregivers to use hand antisepsis, Greene advises. "Have patients be own their advocates when they come into any health care setting," she says. "That's the other important message."

Address equipment disinfection.

Note that equipment or chairs could become soiled with potential contamination from wound drainage of a patient with MRSA, Kallen says.

In the outpatient setting, there is a rapid turnover of patients, Greene points out. "You must thoroughly disinfect equipment between patients," she says. "Far too often we ignore those basics."

The community-acquired strain can be transmitted from what appears to be a young, healthy person to another patient, Greene warns. "It's really just being very proactive and remembering, just because you're dealing with healthy adults, it doesn't mean you shouldn't be very aware and practice all those things," she says.

Focus on preventing all SSIs.

Preventing SSIs, not just MRSA, is the No. 1 desired outcome, Kallen emphasizes.

"It's important to have good infection control process prevention for all SSIs, for all bugs," he says. If you focus simply on MRSA, that "will lead to underappreciation of regular Staph aureus," Kallen says.

Keep up with new research.

Many ongoing studies are addressing decolonization of MRSA and the benefits, Kallen says. "Keep your ears tuned to that type of research," he advises.


  1. Klein E, Smith DL, Laxminarayan R. Community-associated methicillin-resistant Staphylococcus aureus in Outpatients, United States, 1999-2006. Emerg Infect Dis 2009; 15. DOI: 10.3201/eid1512.081341.
  2. Anderson DJ, Kaye KS, Chen LF, et al. Clinical and financial outcomes due to methicillin resistant Staphylococcus aureus surgical-site infection: A multi-center matched outcomes study. PLoS ONE 2009. Doi:10.1371/journal.pone.0008305.
  3. Campbell K. New study finds MRSA on the rise in hospital outpatients — Sevenfold increase in potentially lethal superbug. Nov. 24, 2009. Accessed at
  4. Richer SL, Wenig BL. The efficacy of preoperative screening and the treatment of methicillin-resistant Staphylococcus aureus in an otolaryngology surgical practice. Otolaryngology — Head Neck Surg 2009; 140:29-32. Also presented at the 112th meeting of the American Academy of Otolaryngology — Head and Neck Surgery. Chicago; September 2008.