Pros and Cons of MRSA Screening

This morning’s Chicago Tribune announced that Illinois is reviewing a bill (see SB233 and HB378) to require hospitals to perform tests for methicillin-resistant staphylococcus aureus (MRSA) in all intensive care and “at risk” patients, such as those transferred from nursing homes.

The program requires "active surveillance" for MRSA using a rapid polymerase chain reaction (PCR) assay specific for the super-bug. If positive, strict contact isolation measures are employed, including the use of plastic gowns and gloves and plastic stethoscopes.

Evanston Northwestern Healthcare has taken a very pro-active approach at MRSA screening, spearheaded by Dr. Lance Peterson. Every patient admitted to our hospitals has a nasal swab performed and patients who test positive are placed in contact isolation. According to the Tribune this morning:

Evanston Northwestern went from 1200 cases of patient-to-patient MRSA transmission in 2003 to 80 cases in 2006, and the $600,000-a-year program saved twice as much as it cost by reducing infections, Peterson said.

But this surveillance program is not without its critics.

Active surveillance for MRSA is "an important tool I want to be able to use, but I don't want to be told where and when I have to use it," said Dr. Stephen Weber, an infectious disease specialist at the University of Chicago Medical Center.

Instead, Weber argued, hospitals should be free to direct resources toward the most compelling concerns in their institutions. For instance, the University of Chicago is focusing on reducing infections at surgical sites, which will help control MRSA as well as other drug-resistant bacteria, Weber said.

"It's probably not a good idea to legislate a one-size-fits-all approach, because hospitals have different problems," said Dr. Gary Noskin, associate chief medical officer at Northwestern Memorial Hospital. "The best approach is to rely on each institution's expertise."

Since the bill is supported by the Illinois Hospital Association, a strong push for this initiative seem inevitable.

But from the patient's perspective, contact isolation is no picnic. In my anecdotal experience, I believe patients placed in contact isolation have less contact with health care providers of all types when "isolated." Putting on the gown and gloves and using poor-fidelity plastic stethoscopes has its limitations for the patient, especially in the noisy ICU setting. Medical students and residents rarely visit these patients out of concerns of spreading germs. Teaching rounds are almost never conducted on these patients for similar reasons.

The polymerase chain reaction test used to screen these patients has some limitations as well, including a 1% false positive rate for MRSA. This means that 1% of patients that test positive for MRSA, actually do not have the bug (there is cross reactivity with methicillin sensitive staphylococcus aureus I am told in a small percentage of cases). In these cases, some patients (admittedly few) will be relegated to contact isolation, even though they have a more benign form of staphylococcus aureus in their nose.

So is this legislation the answer? I don't know. But it is sure to have significant implications - both good and bad - for our patients.

-Wes