Superbug breakout: They're harder to beat -- and recognize

Developments regarding certain types of drug-resistant bacteria underscore why such infections are a public health imperative.

By Kathleen Phalen Tomaselli, AMNews correspondent. Feb. 5, 2007.

At first Patricia Raymond, MD, thought it was just an atypical flare-up of a patient's long-standing ulcerative colitis, but it turned out to be community-acquired Clostridium difficile. Perhaps most surprising to the Chesapeake, Va., gastroenterologist was that the patient had no recent antibiotic history, the traditional precursor to C. diff.

Meanwhile, in Portland, Ore., an otherwise healthy young woman was diagnosed with community-associated methicillin-resistant Staphylococcus aureus. She succumbed to the microbial assault in 18 hours. "She was making two toxic shock toxins," says David Gilbert, MD, chief of infectious diseases at Providence Portland Medical Center.

And this year, in KwaZulu-Natal, South Africa, 53 tuberculosis patients were infected with an extensively drug-resistant -- XDR -- strain. Fifty-two died in less than a month.

Such grim tales have become all too familiar: virulent, refractory bugs; unusual microbial behaviors; more toxins; less treatments; and increasing antibiotic resistance.

"It knows no boundaries," says L. Clifford McDonald, MD, a Centers for Disease Control and Prevention medical epidemiologist. "Another factor, at least in cities, may be increased crowding, increased population and increased use of ."

In the past decade new and re-emerging microbial threats have continued to be a worldwide public health challenge. Most troublesome to scientists and physicians is the recent rise of resistant bacteria, particularly among the Big three: C. diff, CA-MRSA and XDR TB.