A Diagnostics & Imaging Week

Evanston Northwestern Healthcare (ENH; Evanston, Illinois), which operates hospitals in three northern suburbs of Chicago, recently launched a systemwide admission screening program across those hospitals to detect methicillin-resistant Staphylococcus aureus (MRSA), a significant cause of hospital-acquired infections.

The Centers for Disease Control and Prevention (CDC; Atlanta) estimates that in 1999 there were 126,000 Americans in U.S. hospitals with infections from MRSA, and the problem has grown worse ever since.

Saying that emerging infections like MRSA are “most acute in large urban areas such as Chicago,” ENH said it has decided to tackle the problem head-on as a major patient safety initiative.

“This initiative is the first of its kind in the country that uses a combination of the electronic medical record [EMR] and same-day molecular testing to screen patients on admission and determine if they are infected with MRSA or are colonized with the bacteria but are not yet infected,” said Lance Peterson, MD, epidemiologist and director of clinical microbiology and infectious disease research at Evanston Northwestern Healthcare.

The combination of these technologies allows doctors to immediately identify and treat patients who may otherwise be unaware of having MRSA. The EMR contains an admission sheet as part of each patient’s treatment plan that prompts the admitting team to order and collect a nasal swab before a healthcare provider moves to the next computer screen. “This electronic ‘red flag’ alert ensures compliance and allows us to document cases in which a patient may refuse the test,” he said.

Peterson, who also is professor of pathology and medicine at Northwestern University’s Feinberg School of Medicine (Chicago), said, “No other hospital in the country has ENH’s level of commitment to reduce MRSA among its patient population.”

He added: “In fact, every member of our community ultimately will benefit from this initiative because patients with active MRSA infections will be isolated and receive immediate treatment; those colonized with the bacteria but not yet infected also will be treated so they don’t develop an active infection or unknowingly spread MRSA to others elsewhere in the hospital or community after they are discharged.”

Each patient’s nasal sample is tested using real-time DNA analysis developed by GeneOhm Sciences (San Diego). The test detects the microorganism at the molecular level and compresses the time frame to identify MRSA from the current two to four days, using traditional culture methods, to less than two hours, the hospital system said.

ENH said patients undergoing a complex medical procedure or surgery are highly susceptible to MRSA, which may already be present on their mucous membranes or skin. It said that one-fourth of the population carries staph bacteria without becoming sick, “but if someone carrying MRSA needs medical treatment such as surgery, there is real risk that the organism will invade the surgical incision.”

Symptoms of MRSA range from mild skin sores to life-threatening surgical wound infections and blood poisonings. Avoiding MRSA infections reduces the need for follow-up surgeries and additional hospitalizations, several weeks of intravenous antibiotics, and a prolonged risk of recurrent infection, ENH said.

“This also makes good economic sense,” said Peggy King, senior vice president, hospitals and clinics, at the hospital, “because it will reduce hospital days and costs associated with treating MRSA complications.”

She said ENH has screened regularly for S. aureus in its highest-risk patient areas, such as the Infant Special Care Unit, for the past two years, “and also conducted a targeted pilot program with a rapid molecular method to screen selected pre-operative patients undergoing knee replacement surgery.”

That program reduced the rate of post-surgical S. aureus infection nearly four-fold, King said. But when the hospital system conducted a prevalence study last September, it found that 8% of its patients in a one-day period of time were colonized with MRSA.

“This incidence reflects a recent finding that between 8% and 9% of inpatients in the Chicago metropolitan area are MRSA carriers and was the impetus for the current initiative,” said Peterson. “Our goal is to reduce the incidence of MRSA infections by 50% over the next two years among our patient population.”

Evanston Northwestern Healthcare includes Evanston, Glenbrook and Highland Park hospitals; ENH Medical Group, comprising 65 medical offices and facilities; ENH Home Services; ENH Research Institute and ENH Foundation.