Evanston Northwestern Healthcare Researchers Explain Effects of Large-Scale, Universal MRSA Surveillance Program That Supports Expanded Intervention

EVANSTON, Ill. -- Universal hospital surveillance of methicillin-resistant Staphylococcus aureus (MRSA) using a rapid molecular diagnostic test is effective in significantly reducing MRSA disease, according to research published in the Annals of Internal Medicine by a team of Evanston Northwestern Healthcare (ENH) researchers. The ENH study, "Universal Surveillance for [MRSA] in 3 Affiliated Hospitals," appears in the March 18, 2008 issue of the American College of Physicians journal, Annals of Internal Medicine.

Evanston Northwestern Healthcare became the first healthcare provider in the United States to launch a comprehensive, universal MRSA surveillance program, swabbing all inpatients at its three hospitals (Evanston, Glenbrook and Highland Park) for the MRSA bacteria, a potentially fatal infection that does not respond to common antibiotics and is a significant cause of hospital-acquired infections.

"The goal of the program was always to reduce the risk of MRSA infection to patients cared for by ENH. We achieved all our benchmarks by the end of the program's first year," said Lance R. Peterson, MD, FASCP, epidemiologist and a founder of the MRSA program at Evanston Northwestern Healthcare. "The program we began in August of 2005 had a major patient safety impact for all our patients and demonstrated that a comprehensive effort to reduce MRSA infection can be accomplished in the United States."

At its three hospitals, ENH was able to reduce MRSA infection rates by 70 percent in less than two years. ENH also demonstrated a systemwide compliance with admission testing of more than 90 percent. The program lowered the risk of other patients and staff becoming carriers of MRSA; and becoming a MRSA carrier is the highest risk for eventually developing an infection with this bacteria.

A new molecular screening test that was approved for patient use shortly before the program began facilitated the ENH initiative. This test shortens the testing time for finding MRSA to under two hours and permits the detection of MRSA carriers the day of admission so that they could be appropriately cared for to reduce spread to others. Peterson stated that, "Reducing spread of MRSA to new patients within the healthcare system is critical to eliminating this infection and the ENH program encompassing over 70,000 patients shows that such a patient-oriented program can be successful."

ENH researchers defined MRSA infection as a combination of all MRSA bloodstream, respiratory, urinary tract, and surgical site infections that occurred during admission and 30 days after discharge. The study concluded that universal screening was associated with a large reduction in MRSA disease during those timeframes.

The study examined the effect of two expanded MRSA surveillance interventions. It compared MRSA rates during and after hospital admission in three consecutive periods: baseline (12 months), MRSA surveillance for all admissions to the intensive care unit (12 months), and universal MRSA surveillance for all hospital admissions (21 months). Only universal surveillance was successful in significantly reducing healthcare-associated MRSA infections.

The screening program involved performing nasal swabs on all inpatients for colonization during the hospital admission process. Electronic medical record and same-day molecular diagnostic testing facilitated quick assessment for MRSA colonization and allowed hospital staff to promptly identify, isolate and treat MRSA-positive patients.

Peterson says, "Our program has successfully prevented nasal colonization of patients coming to ENH for their care. We want people to come here for their healthcare and not go home with something unexpected that will later cause an infection -- and the program is successful in doing just that."

Source: Evanston Northwestern Healthcare