XMRV, a mouse virus, may be an artifact of laboratory experiments rather than the cause of chronic fatigue syndrome. Whittemore Peterson Institute hide caption

itoggle caption Whittemore Peterson Institute

About half of meat and poultry samples nationwide had evidence of S. aureus contamination, a study found. Fuse hide caption

itoggle caption Fuse

A nurse uses an alcohol-based hand gel. A new $1 billion proposal from Health and Human Services aims to cut down on preventable hospital infections and patient readmissions. Dave Weaver/Associated Press hide caption

itoggle caption Dave Weaver/Associated Press