More than 90,000 Americans get potentially deadly infections each year from a drug-resistant staph "superbug," the government reported Tuesday in its first overall estimate of invasive disease caused by the germ.Deaths tied to these infections may exceed those caused by AIDS, said one public health expert commenting on the new study.
          The report shows just how far one form of the staph germ has spread beyond its traditional hospital setting.The overall incidence rate was about 32 invasive infections per 100,000 people. That's an "astounding" figure, said an editorial in Wednesday's Journal of the American Medical Association, which published the study.
         Most drug-resistant staph cases are mild skin infections. But this study focused on invasive infections--those that enter the bloodstream or destroy flesh and can turn deadly. Researchers found that only about one-quarter involved hospitalized patients. However, more than half were in the health care system--people who had recently had surgery or were on kidney dialysis, for example. Open wounds and exposure to medical equipment are major ways the bug spreads.In recent years, the resistant germ has become more common in hospitals and it has been spreading through prisons, gyms and locker rooms, and in poor urban neighborhoods.The new study offers the broadest look yet at the pervasiveness of the most severe infections caused by the bug, called methicillin-resistant Staphylococcus aureus, or MRSA.