ICUs see big drop in dangerous staph superbugs

[February 18, 2009]  CHICAGO (AP) -- A government report says the rate of dangerous staph infections has dropped dramatically in hospital intensive-care units, a rare encouraging sign about a hard-to-treat "superbug." The report involving nearly 600 hospitals is the largest to document a long-term decline in the level of IV tube-related infections of MRSA, a deadly drug-resistant staph germ.

The rate of MRSA bloodstream infections connected with intravenous tubes fell almost 50 percent between 1997 and 2007. The decline occurred at most types of intensive care units that reported these infections to the federal Centers for Disease Control and Prevention during the study period.

"We may actually be starting to get a toehold on" these dangerous germs, said Dr. Buddy Creech, a Vanderbilt University infectious disease specialist who was not involved in the research. "That's encouraging."

In 1997, there were an estimated 43 MRSA infections for every 100,000 intensive-care patients who spent a day hooked up to one of the these IV tubes. By 2007, that number dropped to just 21.

The study authors say the results are likely a sign that doctors and nurses are working harder at prevention efforts. These include frequent hand-washing, instrument sterilization and other measures.

The focus of the study were catheters that are typically threaded into an artery near the heart to deliver medicine or monitor vital signs. These tubes sometimes are hooked up for days and can increase the risks for infection from all kinds of bacteria.

Among the most dangerous are methicillin-resistant Staphylococcus aureus bacteria. These germs often live harmlessly on the skin or in the nose but can spread quickly and become deadly once they enter the bloodstream.

MRSA bacteria can't be treated with common antibiotics, and cause more than 90,000 serious infections and more than 18,000 deaths nationwide each year.

Such infections have been on the rise in schools and other community settings. But patients in health care settings are most vulnerable, and some states including Illinois have adopted or are considering laws requiring MRSA testing or other prevention steps in hospitals.

Incidence of both MRSA and more treatable staph bugs in ICUs fell during the 10-year study period, suggesting that stepped-up prevention efforts are starting to work, the study authors said.

The research appears in Wednesday's Journal of the American Medical Association. An editorial in the journal calls the report evidence of substantial, but also limited, progress.

For example, despite the overall drop in incidence, MRSA became a more common cause of the ICU infections examined than more easily treated staph germs. Over the 10 years, there were nearly 2,500 MRSA bloodstream infections linked to central-line IV tubes, accounting for almost 8 percent of all bloodstream infections associated with these tubes. Other more treatable staph infections accounted for fewer than 5 percent.

Also, the study only addresses infections in intensive-care units; it's unclear whether MRSA infections have declined in other hospital settings, said editorial author Dr. Michael William Climo, an infectious disease specialist at a Hunter Holmes McQuire Veterans Affairs Medical Center in Richmond, Va.

Lead study author Dr. Deron Burton of the CDC said despite the limitations, "We think that this is still a very important success story."

That's because ICU patients are "particularly vulnerable" with higher rates of hospital-related infections, he said.

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On the Net:

JAMA: http://jama.ama-assn.org/

CDC: http://www.cdc.gov/

[Associated Press; By LINDSEY TANNER]

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