Lethal staph infections not so rare

Deadly drug-resistant staph infections, once largely confined to hospitals, are far more common in the general population than previously thought, according to a study in Thursday’s New England Journal of Medicine.

The study examined more than 1,600 cases of the infection caused by a strain of Staphylococcus aureus in Baltimore, Atlanta and Minnesota. Nearly one-fourth of those patients later required hospitalization.

The study, conducted by researchers from the Centers for Disease Control and Prevention and other institutions, confirmed that the organism is circulating widely in the general population.

“There was a remarkable association of a large number of cases, all caused by this drug-resistant strain,” said Dr. Henry F. Chambers, a staph expert at San Francisco General Hospital who wrote an editorial accompanying the study.

Common staph is present on the skin or in the nostrils of about one in three people, typically without causing illness.

In previous research, the drug-resistant strain was found to cause painful skin lesions that resembled infected spider bites, a deadly lung disease known as necrotizing pneumonia and toxic-shock syndrome – a type of blood poisoning that can be fatal.

But doctors outside of hospitals typically don’t look for drug-resistant staph, and therefore don’t order lab tests to verify the strain. Instead, they routinely prescribe ineffective antibiotics, sometimes leading to more severe illnesses and even deaths.

In a separate article in the journal, researchers reported that they have linked drug-resistant staph infections to a rare, often-deadly disease known as necrotizing fasciitis, or more commonly, “flesh eating” syndrome.

“Necrotizing fasciitis is a terrible disease, but before now, Staph aureus was never the cause,” said Dr. Robert Daum, a pediatrics professor at the University of Chicago and one of the first physicians to notice wider circulation of drug-resistant staph.

“Antibiotic resistance and virulence are converging,” he said. “It’s really disturbing.”

The few antibiotics that kill the resistant staph strain are costly, and likely to wane in potency over time, said Dr. Loren Miller, a researcher at the Los Angeles Biomedical Research Institute.

“The problem is we are not developing new antibiotics as fast as we used to because there are very few monetary incentives for pharmaceutical companies to do that,” Miller said. “The bugs are about two steps ahead of us.”