New research has discovered community strains of antibiotic-resistant infections by increasingly showing up among hospital outpatients, are raising the risk of the infection spreading amongst inpatients.

Researchers find, from 1999 to 2006, there has been a seven fold increase in outpatients with methicillin-resistant Staphylococcus aureus (MRSA) infections. Outpatients are patients who are not hospitalized, but receive treatment in emergency departments or surgical centres, or at doctors’ offices associated with hospitals.

This raises the risk of inpatients becoming infected with the community strain, as both outpatients and inpatients use many of the same resources, including surgical centres and the doctors themselves.

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

MRSA has been named for its resistance to methicillin and other antibiotics, bursting into public consciousness in the 1990s. There are several strains of it, including the ‘hospital associated’ i. e. the ones that emerged in hospitals, and the ‘community associated’ that emerged outside hospitals, tending to spread in schools and gyms.

Both strains cause serious, life-threatening illness, though the hospital-acquired strains tend to be generally more virulent. According to background information in the study, about 20,000- Americans die each year from MRSA infections, as the bacteria getting into wounds causes deadly blood or lung infections.

While, there have been several deaths amongst otherwise healthy people, including several children associated with community strains, typically, community-associated strains only cause skin or other soft tissue infections treatable with newer antibiotics.

Whilst, research shows hospital-associated infections remaining relatively stable from 1999 to 2003, even decreasing somewhat between 2003 and 2005, however, community-associated strains posing a risk to hospital inpatients are becoming far more commonplace rising 3.6% in 1999 to 28.2% in 2006, though the study did not find an increase in hospital-associated strains spreading in the community.