Drug-Resistant Strain of Swine Flu Identified

Drug-resistant strains of swine flu are cropping up around the globe - with four cases confirmed at a North Carolina hospital on Friday.

The virus reported at Duke University Medical Center doesn't respond to Tamiflu, one of two medications used to treat severe cases of the bug.

Epidemic experts say they are investigating the apparent spread of Tamiflu-resistant swine flu virus among four patients at Duke University Medical Center in Durham, N.C., and five in a hospital in Wales.

These clusters appear to be the first in which a virus resistant to the antiviral Tamiflu, a mainstay of flu treat, has spread from person to person, researchers said Friday.