Cases of community-acquired MRSA infection, the potentially deadly superbug that is resistant to most antibiotics, are increasing and spreading rapidly into hospitals as well, researchers reported today.

MRSA — methicillin-resistant Staphylococcus aureus -- can attack wounds and trigger lethal bloodstream infections. Infections cause about 20,000 deaths each year in the United States. MRSA has traditionally spread in hospitals, which is called hospital-acquired MRSA. "But the findings from this study suggest that there is a significant reservoir in the community as well," the lead author of the study, Eili Klein, said in a news release. Community-acquired strains can be picked up in almost any public place, such as schools and gyms.

The study analyzed data from 300 microbiology labs serving hospitals around the country and found a sevenfold jump in the proportion of community-acquired MRSA in outpatient hospital units. This is significant because healthcare professionals frequently move between outpatient care settings and hospitals, perhaps facilitating the spread of the germs. Researchers found that MRSA infections increased more than 90% among outpatients with staph infections and now account for more than half of all staph infections.

Community-acquired MRSA is generally less dangerous than hospital-acquired MRSA, but it can still be deadly. Hospital officials, who have already adopted procedures to limit the spread of MRSA, will have to redouble their efforts to stop the community-associated infections. "This emerging epidemic of community-associated MRSA strains appears to add to the already-high MRSA burden in hospitals," said Ramanan Laxminarayan, a researcher with Extending the Cure, a project that examines solutions to antibiotic resistance at the Washington, D.C.-based organization Resources for the Future. Resources for the Future conducted the study with support from the Robert Wood Johnson Foundation. The study appears online in the journal Emerging Infectious Diseases.

It’s important to know the symptoms of a potential MRSA infection because rapid treatment is critical. Here’s an MRSA symptoms fact sheet from the Mayo clinic