MRSA Strain on the Rise in Hospitals
Study Shows Community-Associated MRSA Is Spreading in Health Care Facilities
Nov. 24, 2009 -- A potentially dangerous and rapidly spreading strain of the
"superbug" MRSA poses a much greater public health threat than previously
thought, new research shows.
Community-associated MRSA (CA-MRSA) is spreading in hospitals and other
health care facilities, according to a study in the December issue of
Emerging Infectious Diseases.
The CA-MRSA strain of superbug can be picked up in fitness centers, schools,
and other public places, and is increasing the already significant burden of
MRSA (methicillin-resistant Staphylococcus aureus) in hospitals, the
CA-MRSA and hospital-associated MRSA (HA-MRSA) are bacteria resistant to
most common antibiotics.
HA-MRSA infections occur mostly in hospitals and other health care settings,
including dialysis centers and nursing homes, and often strike mostly older
adults, people having invasive medical procedures, and people with weakened
CA-MRSA is a leading cause of serious skin and soft tissue infections,
entering the body through scrapes and cuts, the researchers say.
The study, which analyzed data from more than 300 microbiology labs across
the U.S., found a sevenfold increase in the proportion of CA-MRSA in
outpatients between 1999 and 2006.
This community-associated strain is making its way into hospitals, the
researchers say, increasing threats to patient safety because patients and
their doctors move back and forth between inpatient and outpatient units of
"This emerging epidemic of community-associated MRSA strains appears to add
to the already high MRSA burden in hospitals," Ramanan Laxminarayan, PhD, MPH,
a senior fellow at Extending the Cure, a project at the Resources for the
Future think tank in Washington, D.C., says in a news release.
This major increase in CA-MRSA, the researchers say, has become a major
Over the length of the study, the scientists report finding that the
proportion of MRSA had increased more than 90% among outpatients with staph,
and now accounts for more than 50% of all Staphyloccus aureus infections.
This was due, the findings suggest, almost entirely to an increase in
Similar increases in inpatients suggest these strains are spreading rapidly
"MRSA has generally been a significant problem only in hospitals," says Eili
Klein, MA, the lead author of the report and also a researcher at Resources for
the Future. "But the findings from this study suggest there is a significant
reservoir in the community as well."
This suggests that the increased cases of CA-MRSA are causing that bug to
spread from the community into hospitals, Klein says.
Hospitals need to take steps to stop this by stepping up infection control
procedures, the researchers say, adding that the best way to contain MRSA and
other superbugs is through surveillance and regular efforts aimed at infection
"Community-associated methicillin-resistant Staphylococcus aureus has become
a major problem in U.S. hospitals already dealing with high levels of
hospital-associated MRSA," the researchers write. They conclude that "more
rapid diagnostic methods are urgently needed to better aid physicians" in