By Amy Norton
MONDAY, April 21, 2014 (HealthDay News) -- An antibiotic-resistant "superbug," long a problem in health-care settings, is now taking up residence in people's homes, a new U.S. study finds.
Methicillin-resistant Staphylococcus aureus, commonly referred to as MRSA, was once mainly confined to places like hospitals and nursing homes, where it can cause severe conditions such as pneumonia and bloodstream infections.
But since the late 1980s, MRSA has also hit the wider community, where it usually causes skin infections, some of them potentially life-threatening. The bug is spread by skin-to-skin contact or through sharing supplies such as towels or razors. And certain groups are at increased risk, including athletes in contact sports and people living in cramped quarters, such as military barracks or prisons.
But in the new study, researchers found that such communal spaces are not the only major MRSA "reservoirs" out there.
"What our findings show is it's also endemic in households," said lead researcher Dr. Anne-Catrin Uhlemann, of Columbia University Medical Center in New York City.
MRSA is called a superbug because it is resistant to many common antibiotics. The new results, published April 21 in Proceedings of the National Academy of Sciences, are based on 161 New York City residents who contracted MRSA infections between 2009 and 2011.
Uhlemann's team analyzed the genetic makeup of MRSA samples from those patients, and took swabs from a comparison group of people the same age who had not fallen ill to see if they harbored any kind of S. aureus bacteria. The researchers also tested other members of each patient's household and their social contacts, and took samples from household surfaces to hunt for S. aureus contamination.
In the end, they found evidence that people's homes were "major reservoirs" of a MRSA strain called USA300 -- which is the chief cause of community MRSA infections across the United States.
Bacteria taken from people living in the same home, for example, were genetically very similar, while there was more genetic variability between samples from different households.
The implication, Uhlemann said, is that "we can't just treat the person with the infection. We have to attempt to remove the (MRSA) colonization from the home."