Affliction, Paperback/Laurell K. Hamilton

Micah's estranged father lies dying, rotting away inside from some strange ailment that has his doctors whispering about -zombie disease.- Anita Blake makes her living off of zombies--but these aren't the kind she knows so well. These creatures hunt in daylight, and are as fast and strong as vampires. If they bite you, you become just like them. And round and round it goes...Where will it stop? Even Anita Blake doesn't know.