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.
These bacteria can be carried by healthy people and
live on their skin or in their noses.
An invasive form
of the disease is being blamed for the death Monday of a
17-year-old Virginia high school senior. Doctors said the
germ had spread to his kidneys, liver, lungs, and
muscles around his heart.
The researchers'
estimates are extrapolated from 2005 surveillance data
from nine mostly urban regions considered representative of
the country. There were 5,287 invasive infections
reported that year in people living in those regions,
which would translate to an estimated 94,360 cases
nationally, the researchers said.
Most cases were
life-threatening bloodstream infections. However, about
10% involved so-called flesh-eating disease, according to
the study led by researchers at the federal Centers
for Disease Control and Prevention.
There were 988
reported deaths among infected people in the study, for a
rate of 6.3 per 100,000. That would translate to 18,650
deaths annually, although the researchers don't know
if MRSA was the cause in all cases.
If these deaths
all were related to staph infections, the total would
exceed other better-known causes of death including AIDS --
which killed an estimated 17,011 Americans in 2005 --
said Elizabeth Bancroft of the Los Angeles County
Health Department, the editorial author.
The results
underscore the need for better prevention measures. That
includes curbing the overuse of antibiotics and improving
hand-washing and other hygiene procedures among
hospital workers, said the CDC's Dr. Scott Fridkin, a
study coauthor.
Some hospitals
have drastically cut infections by first isolating new
patients until they are screened for MRSA.
The bacteria
don't respond to penicillin-related antibiotics once
commonly used to treat them, partly because of overuse. They
can be treated with other drugs, but health officials
worry that their overuse could cause the germ to
become resistant to those too.
A survey earlier
this year suggested that MRSA infections, including
noninvasive mild forms, affect 46 out of every 1,000 U.S.
hospital and nursing home patients -- or as many as
5%. These patients are vulnerable because of open
wounds and invasive medical equipment that can help the
germ spread.
Buddy Creech, an
infectious disease specialist at Vanderbilt University,
said the JAMA study emphasizes the broad scope of the
drug-resistant staph ''epidemic,'' and highlights the
need for a vaccine, which he called ''the holy grail
of staphylococcal research.''
The regions
studied were the state of Connecticut, the city of
Baltimore, and the metropolitan areas of Atlanta;
Denver; Nashville; Portland, Ore.; Rochester, N.Y.;
St. Paul, Minn. [all communities within Ramsey County];
and metropolitan San Francisco. (Lindsey Tanner, AP)