MRSA Creeping Into Hospitals From the Outside

Nov. 25 -- TUESDAY, Nov. 24 (HealthDay News) -- Strains of antibiotic-resistant infections normally found in the community are increasingly showing up among hospital outpatients, raising the risk that inpatients could become infected, new research says.

From 1999 to 2006, researchers found a sevenfold increase in the incidence of outpatients with methicillin-resistant Staphylococcus aureus (MRSA) infections. Outpatients include people treated in emergency departments or surgical centers but not admitted, or at doctors' offices associated with hospitals.

This poses a risk to inpatients because many resources are used by both sets of patients. These include surgical centers and the doctors themselves, who often treat patients both inside and outside of hospitals.

"What this is suggesting is that outpatients are a significant source of MRSA, especially community-associated MRSA strains," said the study's lead author, Eili Klein, a doctoral candidate at Princeton University and a researcher at Resources for the Future, a Washington, D.C.-based think tank. "This suggests the need for incentives to make sure hospitals are not only taking steps to prevent hospital-associated strains from spreading among inpatients, but preventing the spread of community-associated strains through shared resources."

The study is published in the December issue of Emerging Infectious Diseases.

MRSA, which burst into the public consciousness in the 1990s, is named for its resistance to methicillin and other antibiotics. There are several strains, including those that emerged in hospitals, called "hospital associated," and those that emerged outside hospitals and tend to spread in schools and gyms, called "community associated."

While both types can cause serious, life-threatening illness, hospital-acquired strains are generally more virulent. The bacteria can get into wounds, causing deadly blood or lung infections. About 20,000 people in the United States die each year from the MRSA infections, according to background information in the study.