Washington (AP) -- Sen. Robert C. Byrd, the senate's longest-serving member, has developed a serious infection and is being treated in the hospital with antibiotics.
Byrd's office described the staph infection Monday as minor and said the West Virginia democrat is responding well to treatment.
But it has been enough to delay his release from a Washington-area hospital, where he has remained for treatment of an earlier infection for more than two weeks.
Staph infections differ in severity depending on the site of infection, but are more of a threat to people with weakened immune systems and underlying chronic illnesses.
Byrd is 91.
(Copyright 2009 by the Associated Press. All rights reserved.)